chore: vendor

vendor/github.com/theupdateframework/notary/tuf/LICENSE

@@ -0,0 +1,30 @@
+Copyright (c) 2015, Docker Inc.
+Copyright (c) 2014-2015 Prime Directive, Inc.
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Prime Directive, Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/theupdateframework/notary/tuf/README.md

@@ -0,0 +1,6 @@
+## Credits
+
+This implementation was originally forked from [flynn/go-tuf](https://github.com/flynn/go-tuf)
+
+This implementation retains the same 3 Clause BSD license present on 
+the original flynn implementation.

vendor/github.com/theupdateframework/notary/tuf/builder.go

@@ -0,0 +1,732 @@
+package tuf
+
+import (
+	"fmt"
+
+	"github.com/docker/go/canonical/json"
+	"github.com/theupdateframework/notary"
+
+	"github.com/theupdateframework/notary/trustpinning"
+	"github.com/theupdateframework/notary/tuf/data"
+	"github.com/theupdateframework/notary/tuf/signed"
+	"github.com/theupdateframework/notary/tuf/utils"
+)
+
+// ErrBuildDone is returned when any functions are called on RepoBuilder, and it
+// is already finished building
+var ErrBuildDone = fmt.Errorf(
+	"the builder has finished building and cannot accept any more input or produce any more output")
+
+// ErrInvalidBuilderInput is returned when RepoBuilder.Load is called
+// with the wrong type of metadata for the state that it's in
+type ErrInvalidBuilderInput struct{ msg string }
+
+func (e ErrInvalidBuilderInput) Error() string {
+	return e.msg
+}
+
+// ConsistentInfo is the consistent name and size of a role, or just the name
+// of the role and a -1 if no file metadata for the role is known
+type ConsistentInfo struct {
+	RoleName data.RoleName
+	fileMeta data.FileMeta
+}
+
+// ChecksumKnown determines whether or not we know enough to provide a size and
+// consistent name
+func (c ConsistentInfo) ChecksumKnown() bool {
+	// empty hash, no size : this is the zero value
+	return len(c.fileMeta.Hashes) > 0 || c.fileMeta.Length != 0
+}
+
+// ConsistentName returns the consistent name (rolename.sha256) for the role
+// given this consistent information
+func (c ConsistentInfo) ConsistentName() string {
+	return utils.ConsistentName(c.RoleName.String(), c.fileMeta.Hashes[notary.SHA256])
+}
+
+// Length returns the expected length of the role as per this consistent
+// information - if no checksum information is known, the size is -1.
+func (c ConsistentInfo) Length() int64 {
+	if c.ChecksumKnown() {
+		return c.fileMeta.Length
+	}
+	return -1
+}
+
+// RepoBuilder is an interface for an object which builds a tuf.Repo
+type RepoBuilder interface {
+	Load(roleName data.RoleName, content []byte, minVersion int, allowExpired bool) error
+	LoadRootForUpdate(content []byte, minVersion int, isFinal bool) error
+	GenerateSnapshot(prev *data.SignedSnapshot) ([]byte, int, error)
+	GenerateTimestamp(prev *data.SignedTimestamp) ([]byte, int, error)
+	Finish() (*Repo, *Repo, error)
+	BootstrapNewBuilder() RepoBuilder
+	BootstrapNewBuilderWithNewTrustpin(trustpin trustpinning.TrustPinConfig) RepoBuilder
+
+	// informative functions
+	IsLoaded(roleName data.RoleName) bool
+	GetLoadedVersion(roleName data.RoleName) int
+	GetConsistentInfo(roleName data.RoleName) ConsistentInfo
+}
+
+// finishedBuilder refuses any more input or output
+type finishedBuilder struct{}
+
+func (f finishedBuilder) Load(roleName data.RoleName, content []byte, minVersion int, allowExpired bool) error {
+	return ErrBuildDone
+}
+func (f finishedBuilder) LoadRootForUpdate(content []byte, minVersion int, isFinal bool) error {
+	return ErrBuildDone
+}
+func (f finishedBuilder) GenerateSnapshot(prev *data.SignedSnapshot) ([]byte, int, error) {
+	return nil, 0, ErrBuildDone
+}
+func (f finishedBuilder) GenerateTimestamp(prev *data.SignedTimestamp) ([]byte, int, error) {
+	return nil, 0, ErrBuildDone
+}
+func (f finishedBuilder) Finish() (*Repo, *Repo, error)    { return nil, nil, ErrBuildDone }
+func (f finishedBuilder) BootstrapNewBuilder() RepoBuilder { return f }
+func (f finishedBuilder) BootstrapNewBuilderWithNewTrustpin(trustpin trustpinning.TrustPinConfig) RepoBuilder {
+	return f
+}
+func (f finishedBuilder) IsLoaded(roleName data.RoleName) bool        { return false }
+func (f finishedBuilder) GetLoadedVersion(roleName data.RoleName) int { return 0 }
+func (f finishedBuilder) GetConsistentInfo(roleName data.RoleName) ConsistentInfo {
+	return ConsistentInfo{RoleName: roleName}
+}
+
+// NewRepoBuilder is the only way to get a pre-built RepoBuilder
+func NewRepoBuilder(gun data.GUN, cs signed.CryptoService, trustpin trustpinning.TrustPinConfig) RepoBuilder {
+	return NewBuilderFromRepo(gun, NewRepo(cs), trustpin)
+}
+
+// NewBuilderFromRepo allows us to bootstrap a builder given existing repo data.
+// YOU PROBABLY SHOULDN'T BE USING THIS OUTSIDE OF TESTING CODE!!!
+func NewBuilderFromRepo(gun data.GUN, repo *Repo, trustpin trustpinning.TrustPinConfig) RepoBuilder {
+	return &repoBuilderWrapper{
+		RepoBuilder: &repoBuilder{
+			repo:                 repo,
+			invalidRoles:         NewRepo(nil),
+			gun:                  gun,
+			trustpin:             trustpin,
+			loadedNotChecksummed: make(map[data.RoleName][]byte),
+		},
+	}
+}
+
+// repoBuilderWrapper embeds a repoBuilder, but once Finish is called, swaps
+// the embed out with a finishedBuilder
+type repoBuilderWrapper struct {
+	RepoBuilder
+}
+
+func (rbw *repoBuilderWrapper) Finish() (*Repo, *Repo, error) {
+	switch rbw.RepoBuilder.(type) {
+	case finishedBuilder:
+		return rbw.RepoBuilder.Finish()
+	default:
+		old := rbw.RepoBuilder
+		rbw.RepoBuilder = finishedBuilder{}
+		return old.Finish()
+	}
+}
+
+// repoBuilder actually builds a tuf.Repo
+type repoBuilder struct {
+	repo         *Repo
+	invalidRoles *Repo
+
+	// needed for root trust pininng verification
+	gun      data.GUN
+	trustpin trustpinning.TrustPinConfig
+
+	// in case we load root and/or targets before snapshot and timestamp (
+	// or snapshot and not timestamp), so we know what to verify when the
+	// data with checksums come in
+	loadedNotChecksummed map[data.RoleName][]byte
+
+	// bootstrapped values to validate a new root
+	prevRoot                 *data.SignedRoot
+	bootstrappedRootChecksum *data.FileMeta
+
+	// for bootstrapping the next builder
+	nextRootChecksum *data.FileMeta
+}
+
+func (rb *repoBuilder) Finish() (*Repo, *Repo, error) {
+	return rb.repo, rb.invalidRoles, nil
+}
+
+func (rb *repoBuilder) BootstrapNewBuilder() RepoBuilder {
+	return &repoBuilderWrapper{RepoBuilder: &repoBuilder{
+		repo:                 NewRepo(rb.repo.cryptoService),
+		invalidRoles:         NewRepo(nil),
+		gun:                  rb.gun,
+		loadedNotChecksummed: make(map[data.RoleName][]byte),
+		trustpin:             rb.trustpin,
+
+		prevRoot:                 rb.repo.Root,
+		bootstrappedRootChecksum: rb.nextRootChecksum,
+	}}
+}
+
+func (rb *repoBuilder) BootstrapNewBuilderWithNewTrustpin(trustpin trustpinning.TrustPinConfig) RepoBuilder {
+	return &repoBuilderWrapper{RepoBuilder: &repoBuilder{
+		repo:                 NewRepo(rb.repo.cryptoService),
+		gun:                  rb.gun,
+		loadedNotChecksummed: make(map[data.RoleName][]byte),
+		trustpin:             trustpin,
+
+		prevRoot:                 rb.repo.Root,
+		bootstrappedRootChecksum: rb.nextRootChecksum,
+	}}
+}
+
+// IsLoaded returns whether a particular role has already been loaded
+func (rb *repoBuilder) IsLoaded(roleName data.RoleName) bool {
+	switch roleName {
+	case data.CanonicalRootRole:
+		return rb.repo.Root != nil
+	case data.CanonicalSnapshotRole:
+		return rb.repo.Snapshot != nil
+	case data.CanonicalTimestampRole:
+		return rb.repo.Timestamp != nil
+	default:
+		return rb.repo.Targets[roleName] != nil
+	}
+}
+
+// GetLoadedVersion returns the metadata version, if it is loaded, or 1 (the
+// minimum valid version number) otherwise
+func (rb *repoBuilder) GetLoadedVersion(roleName data.RoleName) int {
+	switch {
+	case roleName == data.CanonicalRootRole && rb.repo.Root != nil:
+		return rb.repo.Root.Signed.Version
+	case roleName == data.CanonicalSnapshotRole && rb.repo.Snapshot != nil:
+		return rb.repo.Snapshot.Signed.Version
+	case roleName == data.CanonicalTimestampRole && rb.repo.Timestamp != nil:
+		return rb.repo.Timestamp.Signed.Version
+	default:
+		if tgts, ok := rb.repo.Targets[roleName]; ok {
+			return tgts.Signed.Version
+		}
+	}
+
+	return 1
+}
+
+// GetConsistentInfo returns the consistent name and size of a role, if it is known,
+// otherwise just the rolename and a -1 for size (both of which are inside a
+// ConsistentInfo object)
+func (rb *repoBuilder) GetConsistentInfo(roleName data.RoleName) ConsistentInfo {
+	info := ConsistentInfo{RoleName: roleName} // starts out with unknown filemeta
+	switch roleName {
+	case data.CanonicalTimestampRole:
+		// we do not want to get a consistent timestamp, but we do want to
+		// limit its size
+		info.fileMeta.Length = notary.MaxTimestampSize
+	case data.CanonicalSnapshotRole:
+		if rb.repo.Timestamp != nil {
+			info.fileMeta = rb.repo.Timestamp.Signed.Meta[roleName.String()]
+		}
+	case data.CanonicalRootRole:
+		switch {
+		case rb.bootstrappedRootChecksum != nil:
+			info.fileMeta = *rb.bootstrappedRootChecksum
+		case rb.repo.Snapshot != nil:
+			info.fileMeta = rb.repo.Snapshot.Signed.Meta[roleName.String()]
+		}
+	default:
+		if rb.repo.Snapshot != nil {
+			info.fileMeta = rb.repo.Snapshot.Signed.Meta[roleName.String()]
+		}
+	}
+	return info
+}
+
+func (rb *repoBuilder) Load(roleName data.RoleName, content []byte, minVersion int, allowExpired bool) error {
+	return rb.loadOptions(roleName, content, minVersion, allowExpired, false, false)
+}
+
+// LoadRootForUpdate adds additional flags for updating the root.json file
+func (rb *repoBuilder) LoadRootForUpdate(content []byte, minVersion int, isFinal bool) error {
+	if err := rb.loadOptions(data.CanonicalRootRole, content, minVersion, !isFinal, !isFinal, true); err != nil {
+		return err
+	}
+	if !isFinal {
+		rb.prevRoot = rb.repo.Root
+	}
+	return nil
+}
+
+// loadOptions adds additional flags that should only be used for updating the root.json
+func (rb *repoBuilder) loadOptions(roleName data.RoleName, content []byte, minVersion int, allowExpired, skipChecksum, allowLoaded bool) error {
+	if !data.ValidRole(roleName) {
+		return ErrInvalidBuilderInput{msg: fmt.Sprintf("%s is an invalid role", roleName)}
+	}
+
+	if !allowLoaded && rb.IsLoaded(roleName) {
+		return ErrInvalidBuilderInput{msg: fmt.Sprintf("%s has already been loaded", roleName)}
+	}
+
+	var err error
+	switch roleName {
+	case data.CanonicalRootRole:
+		break
+	case data.CanonicalTimestampRole, data.CanonicalSnapshotRole, data.CanonicalTargetsRole:
+		err = rb.checkPrereqsLoaded([]data.RoleName{data.CanonicalRootRole})
+	default: // delegations
+		err = rb.checkPrereqsLoaded([]data.RoleName{data.CanonicalRootRole, data.CanonicalTargetsRole})
+	}
+	if err != nil {
+		return err
+	}
+
+	switch roleName {
+	case data.CanonicalRootRole:
+		return rb.loadRoot(content, minVersion, allowExpired, skipChecksum)
+	case data.CanonicalSnapshotRole:
+		return rb.loadSnapshot(content, minVersion, allowExpired)
+	case data.CanonicalTimestampRole:
+		return rb.loadTimestamp(content, minVersion, allowExpired)
+	case data.CanonicalTargetsRole:
+		return rb.loadTargets(content, minVersion, allowExpired)
+	default:
+		return rb.loadDelegation(roleName, content, minVersion, allowExpired)
+	}
+}
+
+func (rb *repoBuilder) checkPrereqsLoaded(prereqRoles []data.RoleName) error {
+	for _, req := range prereqRoles {
+		if !rb.IsLoaded(req) {
+			return ErrInvalidBuilderInput{msg: fmt.Sprintf("%s must be loaded first", req)}
+		}
+	}
+	return nil
+}
+
+// GenerateSnapshot generates a new snapshot given a previous (optional) snapshot
+// We can't just load the previous snapshot, because it may have been signed by a different
+// snapshot key (maybe from a previous root version).  Note that we need the root role and
+// targets role to be loaded, because we need to generate metadata for both (and we need
+// the root to be loaded so we can get the snapshot role to sign with)
+func (rb *repoBuilder) GenerateSnapshot(prev *data.SignedSnapshot) ([]byte, int, error) {
+	switch {
+	case rb.repo.cryptoService == nil:
+		return nil, 0, ErrInvalidBuilderInput{msg: "cannot generate snapshot without a cryptoservice"}
+	case rb.IsLoaded(data.CanonicalSnapshotRole):
+		return nil, 0, ErrInvalidBuilderInput{msg: "snapshot has already been loaded"}
+	case rb.IsLoaded(data.CanonicalTimestampRole):
+		return nil, 0, ErrInvalidBuilderInput{msg: "cannot generate snapshot if timestamp has already been loaded"}
+	}
+
+	if err := rb.checkPrereqsLoaded([]data.RoleName{data.CanonicalRootRole}); err != nil {
+		return nil, 0, err
+	}
+
+	// If there is no previous snapshot, we need to generate one, and so the targets must
+	// have already been loaded.  Otherwise, so long as the previous snapshot structure is
+	// valid (it has a targets meta), we're good.
+	switch prev {
+	case nil:
+		if err := rb.checkPrereqsLoaded([]data.RoleName{data.CanonicalTargetsRole}); err != nil {
+			return nil, 0, err
+		}
+
+		if err := rb.repo.InitSnapshot(); err != nil {
+			rb.repo.Snapshot = nil
+			return nil, 0, err
+		}
+	default:
+		if err := data.IsValidSnapshotStructure(prev.Signed); err != nil {
+			return nil, 0, err
+		}
+		rb.repo.Snapshot = prev
+	}
+
+	sgnd, err := rb.repo.SignSnapshot(data.DefaultExpires(data.CanonicalSnapshotRole))
+	if err != nil {
+		rb.repo.Snapshot = nil
+		return nil, 0, err
+	}
+
+	sgndJSON, err := json.Marshal(sgnd)
+	if err != nil {
+		rb.repo.Snapshot = nil
+		return nil, 0, err
+	}
+
+	// loadedNotChecksummed should currently contain the root awaiting checksumming,
+	// since it has to have been loaded.  Since the snapshot was generated using
+	// the root and targets data (there may not be any) that have been loaded,
+	// remove all of them from rb.loadedNotChecksummed
+	for tgtName := range rb.repo.Targets {
+		delete(rb.loadedNotChecksummed, data.RoleName(tgtName))
+	}
+	delete(rb.loadedNotChecksummed, data.CanonicalRootRole)
+
+	// The timestamp can't have been loaded yet, so we want to cache the snapshot
+	// bytes so we can validate the checksum when a timestamp gets generated or
+	// loaded later.
+	rb.loadedNotChecksummed[data.CanonicalSnapshotRole] = sgndJSON
+
+	return sgndJSON, rb.repo.Snapshot.Signed.Version, nil
+}
+
+// GenerateTimestamp generates a new timestamp given a previous (optional) timestamp
+// We can't just load the previous timestamp, because it may have been signed by a different
+// timestamp key (maybe from a previous root version)
+func (rb *repoBuilder) GenerateTimestamp(prev *data.SignedTimestamp) ([]byte, int, error) {
+	switch {
+	case rb.repo.cryptoService == nil:
+		return nil, 0, ErrInvalidBuilderInput{msg: "cannot generate timestamp without a cryptoservice"}
+	case rb.IsLoaded(data.CanonicalTimestampRole):
+		return nil, 0, ErrInvalidBuilderInput{msg: "timestamp has already been loaded"}
+	}
+
+	// SignTimestamp always serializes the loaded snapshot and signs in the data, so we must always
+	// have the snapshot loaded first
+	if err := rb.checkPrereqsLoaded([]data.RoleName{data.CanonicalRootRole, data.CanonicalSnapshotRole}); err != nil {
+		return nil, 0, err
+	}
+
+	switch prev {
+	case nil:
+		if err := rb.repo.InitTimestamp(); err != nil {
+			rb.repo.Timestamp = nil
+			return nil, 0, err
+		}
+	default:
+		if err := data.IsValidTimestampStructure(prev.Signed); err != nil {
+			return nil, 0, err
+		}
+		rb.repo.Timestamp = prev
+	}
+
+	sgnd, err := rb.repo.SignTimestamp(data.DefaultExpires(data.CanonicalTimestampRole))
+	if err != nil {
+		rb.repo.Timestamp = nil
+		return nil, 0, err
+	}
+
+	sgndJSON, err := json.Marshal(sgnd)
+	if err != nil {
+		rb.repo.Timestamp = nil
+		return nil, 0, err
+	}
+
+	// The snapshot should have been loaded (and not checksummed, since a timestamp
+	// cannot have been loaded), so it is awaiting checksumming. Since this
+	// timestamp was generated using the snapshot awaiting checksumming, we can
+	// remove it from rb.loadedNotChecksummed. There should be no other items
+	// awaiting checksumming now since loading/generating a snapshot should have
+	// cleared out everything else in `loadNotChecksummed`.
+	delete(rb.loadedNotChecksummed, data.CanonicalSnapshotRole)
+
+	return sgndJSON, rb.repo.Timestamp.Signed.Version, nil
+}
+
+// loadRoot loads a root if one has not been loaded
+func (rb *repoBuilder) loadRoot(content []byte, minVersion int, allowExpired, skipChecksum bool) error {
+	roleName := data.CanonicalRootRole
+
+	signedObj, err := rb.bytesToSigned(content, data.CanonicalRootRole, skipChecksum)
+	if err != nil {
+		return err
+	}
+	// ValidateRoot validates against the previous root's role, as well as validates that the root
+	// itself is self-consistent with its own signatures and thresholds.
+	// This assumes that ValidateRoot calls data.RootFromSigned, which validates
+	// the metadata, rather than just unmarshalling signedObject into a SignedRoot object itself.
+	signedRoot, err := trustpinning.ValidateRoot(rb.prevRoot, signedObj, rb.gun, rb.trustpin)
+	if err != nil {
+		return err
+	}
+
+	if err := signed.VerifyVersion(&(signedRoot.Signed.SignedCommon), minVersion); err != nil {
+		return err
+	}
+
+	if !allowExpired { // check must go at the end because all other validation should pass
+		if err := signed.VerifyExpiry(&(signedRoot.Signed.SignedCommon), roleName); err != nil {
+			return err
+		}
+	}
+
+	rootRole, err := signedRoot.BuildBaseRole(data.CanonicalRootRole)
+	if err != nil { // this should never happen since the root has been validated
+		return err
+	}
+	rb.repo.Root = signedRoot
+	rb.repo.originalRootRole = rootRole
+	return nil
+}
+
+func (rb *repoBuilder) loadTimestamp(content []byte, minVersion int, allowExpired bool) error {
+	roleName := data.CanonicalTimestampRole
+
+	timestampRole, err := rb.repo.Root.BuildBaseRole(roleName)
+	if err != nil { // this should never happen, since it's already been validated
+		return err
+	}
+
+	signedObj, err := rb.bytesToSignedAndValidateSigs(timestampRole, content)
+	if err != nil {
+		return err
+	}
+
+	signedTimestamp, err := data.TimestampFromSigned(signedObj)
+	if err != nil {
+		return err
+	}
+
+	if err := signed.VerifyVersion(&(signedTimestamp.Signed.SignedCommon), minVersion); err != nil {
+		return err
+	}
+
+	if !allowExpired { // check must go at the end because all other validation should pass
+		if err := signed.VerifyExpiry(&(signedTimestamp.Signed.SignedCommon), roleName); err != nil {
+			return err
+		}
+	}
+
+	if err := rb.validateChecksumsFromTimestamp(signedTimestamp); err != nil {
+		return err
+	}
+
+	rb.repo.Timestamp = signedTimestamp
+	return nil
+}
+
+func (rb *repoBuilder) loadSnapshot(content []byte, minVersion int, allowExpired bool) error {
+	roleName := data.CanonicalSnapshotRole
+
+	snapshotRole, err := rb.repo.Root.BuildBaseRole(roleName)
+	if err != nil { // this should never happen, since it's already been validated
+		return err
+	}
+
+	signedObj, err := rb.bytesToSignedAndValidateSigs(snapshotRole, content)
+	if err != nil {
+		return err
+	}
+
+	signedSnapshot, err := data.SnapshotFromSigned(signedObj)
+	if err != nil {
+		return err
+	}
+
+	if err := signed.VerifyVersion(&(signedSnapshot.Signed.SignedCommon), minVersion); err != nil {
+		return err
+	}
+
+	if !allowExpired { // check must go at the end because all other validation should pass
+		if err := signed.VerifyExpiry(&(signedSnapshot.Signed.SignedCommon), roleName); err != nil {
+			return err
+		}
+	}
+
+	// at this point, the only thing left to validate is existing checksums - we can use
+	// this snapshot to bootstrap the next builder if needed - and we don't need to do
+	// the 2-value assignment since we've already validated the signedSnapshot, which MUST
+	// have root metadata
+	rootMeta := signedSnapshot.Signed.Meta[data.CanonicalRootRole.String()]
+	rb.nextRootChecksum = &rootMeta
+
+	if err := rb.validateChecksumsFromSnapshot(signedSnapshot); err != nil {
+		return err
+	}
+
+	rb.repo.Snapshot = signedSnapshot
+	return nil
+}
+
+func (rb *repoBuilder) loadTargets(content []byte, minVersion int, allowExpired bool) error {
+	roleName := data.CanonicalTargetsRole
+
+	targetsRole, err := rb.repo.Root.BuildBaseRole(roleName)
+	if err != nil { // this should never happen, since it's already been validated
+		return err
+	}
+
+	signedObj, err := rb.bytesToSignedAndValidateSigs(targetsRole, content)
+	if err != nil {
+		return err
+	}
+
+	signedTargets, err := data.TargetsFromSigned(signedObj, roleName)
+	if err != nil {
+		return err
+	}
+
+	if err := signed.VerifyVersion(&(signedTargets.Signed.SignedCommon), minVersion); err != nil {
+		return err
+	}
+
+	if !allowExpired { // check must go at the end because all other validation should pass
+		if err := signed.VerifyExpiry(&(signedTargets.Signed.SignedCommon), roleName); err != nil {
+			return err
+		}
+	}
+
+	signedTargets.Signatures = signedObj.Signatures
+	rb.repo.Targets[roleName] = signedTargets
+	return nil
+}
+
+func (rb *repoBuilder) loadDelegation(roleName data.RoleName, content []byte, minVersion int, allowExpired bool) error {
+	delegationRole, err := rb.repo.GetDelegationRole(roleName)
+	if err != nil {
+		return err
+	}
+
+	// bytesToSigned checks checksum
+	signedObj, err := rb.bytesToSigned(content, roleName, false)
+	if err != nil {
+		return err
+	}
+
+	signedTargets, err := data.TargetsFromSigned(signedObj, roleName)
+	if err != nil {
+		return err
+	}
+
+	if err := signed.VerifyVersion(&(signedTargets.Signed.SignedCommon), minVersion); err != nil {
+		// don't capture in invalidRoles because the role we received is a rollback
+		return err
+	}
+
+	// verify signature
+	if err := signed.VerifySignatures(signedObj, delegationRole.BaseRole); err != nil {
+		rb.invalidRoles.Targets[roleName] = signedTargets
+		return err
+	}
+
+	if !allowExpired { // check must go at the end because all other validation should pass
+		if err := signed.VerifyExpiry(&(signedTargets.Signed.SignedCommon), roleName); err != nil {
+			rb.invalidRoles.Targets[roleName] = signedTargets
+			return err
+		}
+	}
+
+	signedTargets.Signatures = signedObj.Signatures
+	rb.repo.Targets[roleName] = signedTargets
+	return nil
+}
+
+func (rb *repoBuilder) validateChecksumsFromTimestamp(ts *data.SignedTimestamp) error {
+	sn, ok := rb.loadedNotChecksummed[data.CanonicalSnapshotRole]
+	if ok {
+		// by this point, the SignedTimestamp has been validated so it must have a snapshot hash
+		snMeta := ts.Signed.Meta[data.CanonicalSnapshotRole.String()].Hashes
+		if err := data.CheckHashes(sn, data.CanonicalSnapshotRole.String(), snMeta); err != nil {
+			return err
+		}
+		delete(rb.loadedNotChecksummed, data.CanonicalSnapshotRole)
+	}
+	return nil
+}
+
+func (rb *repoBuilder) validateChecksumsFromSnapshot(sn *data.SignedSnapshot) error {
+	var goodRoles []data.RoleName
+	for roleName, loadedBytes := range rb.loadedNotChecksummed {
+		switch roleName {
+		case data.CanonicalSnapshotRole, data.CanonicalTimestampRole:
+			break
+		default:
+			if err := data.CheckHashes(loadedBytes, roleName.String(), sn.Signed.Meta[roleName.String()].Hashes); err != nil {
+				return err
+			}
+			goodRoles = append(goodRoles, roleName)
+		}
+	}
+	for _, roleName := range goodRoles {
+		delete(rb.loadedNotChecksummed, roleName)
+	}
+	return nil
+}
+
+func (rb *repoBuilder) validateChecksumFor(content []byte, roleName data.RoleName) error {
+	// validate the bootstrap checksum for root, if provided
+	if roleName == data.CanonicalRootRole && rb.bootstrappedRootChecksum != nil {
+		if err := data.CheckHashes(content, roleName.String(), rb.bootstrappedRootChecksum.Hashes); err != nil {
+			return err
+		}
+	}
+
+	// but we also want to cache the root content, so that when the snapshot is
+	// loaded it is validated (to make sure everything in the repo is self-consistent)
+	checksums := rb.getChecksumsFor(roleName)
+	if checksums != nil { // as opposed to empty, in which case hash check should fail
+		if err := data.CheckHashes(content, roleName.String(), *checksums); err != nil {
+			return err
+		}
+	} else if roleName != data.CanonicalTimestampRole {
+		// timestamp is the only role which does not need to be checksummed, but
+		// for everything else, cache the contents in the list of roles that have
+		// not been checksummed by the snapshot/timestamp yet
+		rb.loadedNotChecksummed[roleName] = content
+	}
+
+	return nil
+}
+
+// Checksums the given bytes, and if they validate, convert to a data.Signed object.
+// If a checksums are nil (as opposed to empty), adds the bytes to the list of roles that
+// haven't been checksummed (unless it's a timestamp, which has no checksum reference).
+func (rb *repoBuilder) bytesToSigned(content []byte, roleName data.RoleName, skipChecksum bool) (*data.Signed, error) {
+	if !skipChecksum {
+		if err := rb.validateChecksumFor(content, roleName); err != nil {
+			return nil, err
+		}
+	}
+
+	// unmarshal to signed
+	signedObj := &data.Signed{}
+	if err := json.Unmarshal(content, signedObj); err != nil {
+		return nil, err
+	}
+
+	return signedObj, nil
+}
+
+func (rb *repoBuilder) bytesToSignedAndValidateSigs(role data.BaseRole, content []byte) (*data.Signed, error) {
+
+	signedObj, err := rb.bytesToSigned(content, role.Name, false)
+	if err != nil {
+		return nil, err
+	}
+
+	// verify signature
+	if err := signed.VerifySignatures(signedObj, role); err != nil {
+		return nil, err
+	}
+
+	return signedObj, nil
+}
+
+// If the checksum reference (the loaded timestamp for the snapshot role, and
+// the loaded snapshot for every other role except timestamp and snapshot) is nil,
+// then return nil for the checksums, meaning that the checksum is not yet
+// available.  If the checksum reference *is* loaded, then always returns the
+// Hashes object for the given role - if it doesn't exist, returns an empty Hash
+// object (against which any checksum validation would fail).
+func (rb *repoBuilder) getChecksumsFor(role data.RoleName) *data.Hashes {
+	var hashes data.Hashes
+	switch role {
+	case data.CanonicalTimestampRole:
+		return nil
+	case data.CanonicalSnapshotRole:
+		if rb.repo.Timestamp == nil {
+			return nil
+		}
+		hashes = rb.repo.Timestamp.Signed.Meta[data.CanonicalSnapshotRole.String()].Hashes
+	default:
+		if rb.repo.Snapshot == nil {
+			return nil
+		}
+		hashes = rb.repo.Snapshot.Signed.Meta[role.String()].Hashes
+	}
+	return &hashes
+}

vendor/github.com/theupdateframework/notary/tuf/data/errors.go

@@ -0,0 +1,53 @@
+package data
+
+import "fmt"
+
+// ErrInvalidMetadata is the error to be returned when metadata is invalid
+type ErrInvalidMetadata struct {
+	role RoleName
+	msg  string
+}
+
+func (e ErrInvalidMetadata) Error() string {
+	return fmt.Sprintf("%s type metadata invalid: %s", e.role.String(), e.msg)
+}
+
+// ErrMissingMeta - couldn't find the FileMeta object for the given Role, or
+// the FileMeta object contained no supported checksums
+type ErrMissingMeta struct {
+	Role string
+}
+
+func (e ErrMissingMeta) Error() string {
+	return fmt.Sprintf("no checksums for supported algorithms were provided for %s", e.Role)
+}
+
+// ErrInvalidChecksum is the error to be returned when checksum is invalid
+type ErrInvalidChecksum struct {
+	alg string
+}
+
+func (e ErrInvalidChecksum) Error() string {
+	return fmt.Sprintf("%s checksum invalid", e.alg)
+}
+
+// ErrMismatchedChecksum is the error to be returned when checksum is mismatched
+type ErrMismatchedChecksum struct {
+	alg      string
+	name     string
+	expected string
+}
+
+func (e ErrMismatchedChecksum) Error() string {
+	return fmt.Sprintf("%s checksum for %s did not match: expected %s", e.alg, e.name,
+		e.expected)
+}
+
+// ErrCertExpired is the error to be returned when a certificate has expired
+type ErrCertExpired struct {
+	CN string
+}
+
+func (e ErrCertExpired) Error() string {
+	return fmt.Sprintf("certificate with CN %s is expired", e.CN)
+}

vendor/github.com/theupdateframework/notary/tuf/data/keys.go

@@ -0,0 +1,529 @@
+package data
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"crypto/sha256"
+	"crypto/x509"
+	"encoding/asn1"
+	"encoding/hex"
+	"errors"
+	"io"
+	"math/big"
+
+	"github.com/docker/go/canonical/json"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/crypto/ed25519"
+)
+
+// PublicKey is the necessary interface for public keys
+type PublicKey interface {
+	ID() string
+	Algorithm() string
+	Public() []byte
+}
+
+// PrivateKey adds the ability to access the private key
+type PrivateKey interface {
+	PublicKey
+	Sign(rand io.Reader, msg []byte, opts crypto.SignerOpts) (signature []byte, err error)
+	Private() []byte
+	CryptoSigner() crypto.Signer
+	SignatureAlgorithm() SigAlgorithm
+}
+
+// KeyPair holds the public and private key bytes
+type KeyPair struct {
+	Public  []byte `json:"public"`
+	Private []byte `json:"private"`
+}
+
+// Keys represents a map of key ID to PublicKey object. It's necessary
+// to allow us to unmarshal into an interface via the json.Unmarshaller
+// interface
+type Keys map[string]PublicKey
+
+// UnmarshalJSON implements the json.Unmarshaller interface
+func (ks *Keys) UnmarshalJSON(data []byte) error {
+	parsed := make(map[string]TUFKey)
+	err := json.Unmarshal(data, &parsed)
+	if err != nil {
+		return err
+	}
+	final := make(map[string]PublicKey)
+	for k, tk := range parsed {
+		final[k] = typedPublicKey(tk)
+	}
+	*ks = final
+	return nil
+}
+
+// KeyList represents a list of keys
+type KeyList []PublicKey
+
+// UnmarshalJSON implements the json.Unmarshaller interface
+func (ks *KeyList) UnmarshalJSON(data []byte) error {
+	parsed := make([]TUFKey, 0, 1)
+	err := json.Unmarshal(data, &parsed)
+	if err != nil {
+		return err
+	}
+	final := make([]PublicKey, 0, len(parsed))
+	for _, tk := range parsed {
+		final = append(final, typedPublicKey(tk))
+	}
+	*ks = final
+	return nil
+}
+
+// IDs generates a list of the hex encoded key IDs in the KeyList
+func (ks KeyList) IDs() []string {
+	keyIDs := make([]string, 0, len(ks))
+	for _, k := range ks {
+		keyIDs = append(keyIDs, k.ID())
+	}
+	return keyIDs
+}
+
+func typedPublicKey(tk TUFKey) PublicKey {
+	switch tk.Algorithm() {
+	case ECDSAKey:
+		return &ECDSAPublicKey{TUFKey: tk}
+	case ECDSAx509Key:
+		return &ECDSAx509PublicKey{TUFKey: tk}
+	case RSAKey:
+		return &RSAPublicKey{TUFKey: tk}
+	case RSAx509Key:
+		return &RSAx509PublicKey{TUFKey: tk}
+	case ED25519Key:
+		return &ED25519PublicKey{TUFKey: tk}
+	}
+	return &UnknownPublicKey{TUFKey: tk}
+}
+
+func typedPrivateKey(tk TUFKey) (PrivateKey, error) {
+	private := tk.Value.Private
+	tk.Value.Private = nil
+	switch tk.Algorithm() {
+	case ECDSAKey:
+		return NewECDSAPrivateKey(
+			&ECDSAPublicKey{
+				TUFKey: tk,
+			},
+			private,
+		)
+	case ECDSAx509Key:
+		return NewECDSAPrivateKey(
+			&ECDSAx509PublicKey{
+				TUFKey: tk,
+			},
+			private,
+		)
+	case RSAKey:
+		return NewRSAPrivateKey(
+			&RSAPublicKey{
+				TUFKey: tk,
+			},
+			private,
+		)
+	case RSAx509Key:
+		return NewRSAPrivateKey(
+			&RSAx509PublicKey{
+				TUFKey: tk,
+			},
+			private,
+		)
+	case ED25519Key:
+		return NewED25519PrivateKey(
+			ED25519PublicKey{
+				TUFKey: tk,
+			},
+			private,
+		)
+	}
+	return &UnknownPrivateKey{
+		TUFKey:     tk,
+		privateKey: privateKey{private: private},
+	}, nil
+}
+
+// NewPublicKey creates a new, correctly typed PublicKey, using the
+// UnknownPublicKey catchall for unsupported ciphers
+func NewPublicKey(alg string, public []byte) PublicKey {
+	tk := TUFKey{
+		Type: alg,
+		Value: KeyPair{
+			Public: public,
+		},
+	}
+	return typedPublicKey(tk)
+}
+
+// NewPrivateKey creates a new, correctly typed PrivateKey, using the
+// UnknownPrivateKey catchall for unsupported ciphers
+func NewPrivateKey(pubKey PublicKey, private []byte) (PrivateKey, error) {
+	tk := TUFKey{
+		Type: pubKey.Algorithm(),
+		Value: KeyPair{
+			Public:  pubKey.Public(),
+			Private: private, // typedPrivateKey moves this value
+		},
+	}
+	return typedPrivateKey(tk)
+}
+
+// UnmarshalPublicKey is used to parse individual public keys in JSON
+func UnmarshalPublicKey(data []byte) (PublicKey, error) {
+	var parsed TUFKey
+	err := json.Unmarshal(data, &parsed)
+	if err != nil {
+		return nil, err
+	}
+	return typedPublicKey(parsed), nil
+}
+
+// UnmarshalPrivateKey is used to parse individual private keys in JSON
+func UnmarshalPrivateKey(data []byte) (PrivateKey, error) {
+	var parsed TUFKey
+	err := json.Unmarshal(data, &parsed)
+	if err != nil {
+		return nil, err
+	}
+	return typedPrivateKey(parsed)
+}
+
+// TUFKey is the structure used for both public and private keys in TUF.
+// Normally it would make sense to use a different structures for public and
+// private keys, but that would change the key ID algorithm (since the canonical
+// JSON would be different). This structure should normally be accessed through
+// the PublicKey or PrivateKey interfaces.
+type TUFKey struct {
+	id    string
+	Type  string  `json:"keytype"`
+	Value KeyPair `json:"keyval"`
+}
+
+// Algorithm returns the algorithm of the key
+func (k TUFKey) Algorithm() string {
+	return k.Type
+}
+
+// ID efficiently generates if necessary, and caches the ID of the key
+func (k *TUFKey) ID() string {
+	if k.id == "" {
+		pubK := TUFKey{
+			Type: k.Algorithm(),
+			Value: KeyPair{
+				Public:  k.Public(),
+				Private: nil,
+			},
+		}
+		data, err := json.MarshalCanonical(&pubK)
+		if err != nil {
+			logrus.Error("Error generating key ID:", err)
+		}
+		digest := sha256.Sum256(data)
+		k.id = hex.EncodeToString(digest[:])
+	}
+	return k.id
+}
+
+// Public returns the public bytes
+func (k TUFKey) Public() []byte {
+	return k.Value.Public
+}
+
+// Public key types
+
+// ECDSAPublicKey represents an ECDSA key using a raw serialization
+// of the public key
+type ECDSAPublicKey struct {
+	TUFKey
+}
+
+// ECDSAx509PublicKey represents an ECDSA key using an x509 cert
+// as the serialized format of the public key
+type ECDSAx509PublicKey struct {
+	TUFKey
+}
+
+// RSAPublicKey represents an RSA key using a raw serialization
+// of the public key
+type RSAPublicKey struct {
+	TUFKey
+}
+
+// RSAx509PublicKey represents an RSA key using an x509 cert
+// as the serialized format of the public key
+type RSAx509PublicKey struct {
+	TUFKey
+}
+
+// ED25519PublicKey represents an ED25519 key using a raw serialization
+// of the public key
+type ED25519PublicKey struct {
+	TUFKey
+}
+
+// UnknownPublicKey is a catchall for key types that are not supported
+type UnknownPublicKey struct {
+	TUFKey
+}
+
+// NewECDSAPublicKey initializes a new public key with the ECDSAKey type
+func NewECDSAPublicKey(public []byte) *ECDSAPublicKey {
+	return &ECDSAPublicKey{
+		TUFKey: TUFKey{
+			Type: ECDSAKey,
+			Value: KeyPair{
+				Public:  public,
+				Private: nil,
+			},
+		},
+	}
+}
+
+// NewECDSAx509PublicKey initializes a new public key with the ECDSAx509Key type
+func NewECDSAx509PublicKey(public []byte) *ECDSAx509PublicKey {
+	return &ECDSAx509PublicKey{
+		TUFKey: TUFKey{
+			Type: ECDSAx509Key,
+			Value: KeyPair{
+				Public:  public,
+				Private: nil,
+			},
+		},
+	}
+}
+
+// NewRSAPublicKey initializes a new public key with the RSA type
+func NewRSAPublicKey(public []byte) *RSAPublicKey {
+	return &RSAPublicKey{
+		TUFKey: TUFKey{
+			Type: RSAKey,
+			Value: KeyPair{
+				Public:  public,
+				Private: nil,
+			},
+		},
+	}
+}
+
+// NewRSAx509PublicKey initializes a new public key with the RSAx509Key type
+func NewRSAx509PublicKey(public []byte) *RSAx509PublicKey {
+	return &RSAx509PublicKey{
+		TUFKey: TUFKey{
+			Type: RSAx509Key,
+			Value: KeyPair{
+				Public:  public,
+				Private: nil,
+			},
+		},
+	}
+}
+
+// NewED25519PublicKey initializes a new public key with the ED25519Key type
+func NewED25519PublicKey(public []byte) *ED25519PublicKey {
+	return &ED25519PublicKey{
+		TUFKey: TUFKey{
+			Type: ED25519Key,
+			Value: KeyPair{
+				Public:  public,
+				Private: nil,
+			},
+		},
+	}
+}
+
+// Private key types
+type privateKey struct {
+	private []byte
+}
+
+type signer struct {
+	signer crypto.Signer
+}
+
+// ECDSAPrivateKey represents a private ECDSA key
+type ECDSAPrivateKey struct {
+	PublicKey
+	privateKey
+	signer
+}
+
+// RSAPrivateKey represents a private RSA key
+type RSAPrivateKey struct {
+	PublicKey
+	privateKey
+	signer
+}
+
+// ED25519PrivateKey represents a private ED25519 key
+type ED25519PrivateKey struct {
+	ED25519PublicKey
+	privateKey
+}
+
+// UnknownPrivateKey is a catchall for unsupported key types
+type UnknownPrivateKey struct {
+	TUFKey
+	privateKey
+}
+
+// NewECDSAPrivateKey initializes a new ECDSA private key
+func NewECDSAPrivateKey(public PublicKey, private []byte) (*ECDSAPrivateKey, error) {
+	switch public.(type) {
+	case *ECDSAPublicKey, *ECDSAx509PublicKey:
+	default:
+		return nil, errors.New("invalid public key type provided to NewECDSAPrivateKey")
+	}
+	ecdsaPrivKey, err := x509.ParseECPrivateKey(private)
+	if err != nil {
+		return nil, err
+	}
+	return &ECDSAPrivateKey{
+		PublicKey:  public,
+		privateKey: privateKey{private: private},
+		signer:     signer{signer: ecdsaPrivKey},
+	}, nil
+}
+
+// NewRSAPrivateKey initialized a new RSA private key
+func NewRSAPrivateKey(public PublicKey, private []byte) (*RSAPrivateKey, error) {
+	switch public.(type) {
+	case *RSAPublicKey, *RSAx509PublicKey:
+	default:
+		return nil, errors.New("invalid public key type provided to NewRSAPrivateKey")
+	}
+	rsaPrivKey, err := x509.ParsePKCS1PrivateKey(private)
+	if err != nil {
+		return nil, err
+	}
+	return &RSAPrivateKey{
+		PublicKey:  public,
+		privateKey: privateKey{private: private},
+		signer:     signer{signer: rsaPrivKey},
+	}, nil
+}
+
+// NewED25519PrivateKey initialized a new ED25519 private key
+func NewED25519PrivateKey(public ED25519PublicKey, private []byte) (*ED25519PrivateKey, error) {
+	return &ED25519PrivateKey{
+		ED25519PublicKey: public,
+		privateKey:       privateKey{private: private},
+	}, nil
+}
+
+// Private return the serialized private bytes of the key
+func (k privateKey) Private() []byte {
+	return k.private
+}
+
+// CryptoSigner returns the underlying crypto.Signer for use cases where we need the default
+// signature or public key functionality (like when we generate certificates)
+func (s signer) CryptoSigner() crypto.Signer {
+	return s.signer
+}
+
+// CryptoSigner returns the ED25519PrivateKey which already implements crypto.Signer
+func (k ED25519PrivateKey) CryptoSigner() crypto.Signer {
+	return nil
+}
+
+// CryptoSigner returns the UnknownPrivateKey which already implements crypto.Signer
+func (k UnknownPrivateKey) CryptoSigner() crypto.Signer {
+	return nil
+}
+
+type ecdsaSig struct {
+	R *big.Int
+	S *big.Int
+}
+
+// Sign creates an ecdsa signature
+func (k ECDSAPrivateKey) Sign(rand io.Reader, msg []byte, opts crypto.SignerOpts) (signature []byte, err error) {
+	ecdsaPrivKey, ok := k.CryptoSigner().(*ecdsa.PrivateKey)
+	if !ok {
+		return nil, errors.New("signer was based on the wrong key type")
+	}
+	hashed := sha256.Sum256(msg)
+	sigASN1, err := ecdsaPrivKey.Sign(rand, hashed[:], opts)
+	if err != nil {
+		return nil, err
+	}
+
+	sig := ecdsaSig{}
+	_, err = asn1.Unmarshal(sigASN1, &sig)
+	if err != nil {
+		return nil, err
+	}
+	rBytes, sBytes := sig.R.Bytes(), sig.S.Bytes()
+	octetLength := (ecdsaPrivKey.Params().BitSize + 7) >> 3
+
+	// MUST include leading zeros in the output
+	rBuf := make([]byte, octetLength-len(rBytes), octetLength)
+	sBuf := make([]byte, octetLength-len(sBytes), octetLength)
+
+	rBuf = append(rBuf, rBytes...)
+	sBuf = append(sBuf, sBytes...)
+	return append(rBuf, sBuf...), nil
+}
+
+// Sign creates an rsa signature
+func (k RSAPrivateKey) Sign(rand io.Reader, msg []byte, opts crypto.SignerOpts) (signature []byte, err error) {
+	hashed := sha256.Sum256(msg)
+	if opts == nil {
+		opts = &rsa.PSSOptions{
+			SaltLength: rsa.PSSSaltLengthEqualsHash,
+			Hash:       crypto.SHA256,
+		}
+	}
+	return k.CryptoSigner().Sign(rand, hashed[:], opts)
+}
+
+// Sign creates an ed25519 signature
+func (k ED25519PrivateKey) Sign(rand io.Reader, msg []byte, opts crypto.SignerOpts) (signature []byte, err error) {
+	priv := make([]byte, ed25519.PrivateKeySize)
+	// The ed25519 key is serialized as public key then private key, so just use private key here.
+	copy(priv, k.private[ed25519.PublicKeySize:])
+	return ed25519.Sign(ed25519.PrivateKey(priv), msg)[:], nil
+}
+
+// Sign on an UnknownPrivateKey raises an error because the client does not
+// know how to sign with this key type.
+func (k UnknownPrivateKey) Sign(rand io.Reader, msg []byte, opts crypto.SignerOpts) (signature []byte, err error) {
+	return nil, errors.New("unknown key type, cannot sign")
+}
+
+// SignatureAlgorithm returns the SigAlgorithm for a ECDSAPrivateKey
+func (k ECDSAPrivateKey) SignatureAlgorithm() SigAlgorithm {
+	return ECDSASignature
+}
+
+// SignatureAlgorithm returns the SigAlgorithm for a RSAPrivateKey
+func (k RSAPrivateKey) SignatureAlgorithm() SigAlgorithm {
+	return RSAPSSSignature
+}
+
+// SignatureAlgorithm returns the SigAlgorithm for a ED25519PrivateKey
+func (k ED25519PrivateKey) SignatureAlgorithm() SigAlgorithm {
+	return EDDSASignature
+}
+
+// SignatureAlgorithm returns the SigAlgorithm for an UnknownPrivateKey
+func (k UnknownPrivateKey) SignatureAlgorithm() SigAlgorithm {
+	return ""
+}
+
+// PublicKeyFromPrivate returns a new TUFKey based on a private key, with
+// the private key bytes guaranteed to be nil.
+func PublicKeyFromPrivate(pk PrivateKey) PublicKey {
+	return typedPublicKey(TUFKey{
+		Type: pk.Algorithm(),
+		Value: KeyPair{
+			Public:  pk.Public(),
+			Private: nil,
+		},
+	})
+}

vendor/github.com/theupdateframework/notary/tuf/data/roles.go

@@ -0,0 +1,339 @@
+package data
+
+import (
+	"fmt"
+	"path"
+	"regexp"
+	"strings"
+
+	"github.com/sirupsen/logrus"
+)
+
+// Canonical base role names
+var (
+	CanonicalRootRole      RoleName = "root"
+	CanonicalTargetsRole   RoleName = "targets"
+	CanonicalSnapshotRole  RoleName = "snapshot"
+	CanonicalTimestampRole RoleName = "timestamp"
+)
+
+// BaseRoles is an easy to iterate list of the top level
+// roles.
+var BaseRoles = []RoleName{
+	CanonicalRootRole,
+	CanonicalTargetsRole,
+	CanonicalSnapshotRole,
+	CanonicalTimestampRole,
+}
+
+// Regex for validating delegation names
+var delegationRegexp = regexp.MustCompile("^[-a-z0-9_/]+$")
+
+// ErrNoSuchRole indicates the roles doesn't exist
+type ErrNoSuchRole struct {
+	Role RoleName
+}
+
+func (e ErrNoSuchRole) Error() string {
+	return fmt.Sprintf("role does not exist: %s", e.Role)
+}
+
+// ErrInvalidRole represents an error regarding a role. Typically
+// something like a role for which sone of the public keys were
+// not found in the TUF repo.
+type ErrInvalidRole struct {
+	Role   RoleName
+	Reason string
+}
+
+func (e ErrInvalidRole) Error() string {
+	if e.Reason != "" {
+		return fmt.Sprintf("tuf: invalid role %s. %s", e.Role, e.Reason)
+	}
+	return fmt.Sprintf("tuf: invalid role %s.", e.Role)
+}
+
+// ValidRole only determines the name is semantically
+// correct. For target delegated roles, it does NOT check
+// the appropriate parent roles exist.
+func ValidRole(name RoleName) bool {
+	if IsDelegation(name) {
+		return true
+	}
+
+	for _, v := range BaseRoles {
+		if name == v {
+			return true
+		}
+	}
+	return false
+}
+
+// IsDelegation checks if the role is a delegation or a root role
+func IsDelegation(role RoleName) bool {
+	strRole := role.String()
+	targetsBase := CanonicalTargetsRole + "/"
+
+	whitelistedChars := delegationRegexp.MatchString(strRole)
+
+	// Limit size of full role string to 255 chars for db column size limit
+	correctLength := len(role) < 256
+
+	// Removes ., .., extra slashes, and trailing slash
+	isClean := path.Clean(strRole) == strRole
+	return strings.HasPrefix(strRole, targetsBase.String()) &&
+		whitelistedChars &&
+		correctLength &&
+		isClean
+}
+
+// IsBaseRole checks if the role is a base role
+func IsBaseRole(role RoleName) bool {
+	for _, baseRole := range BaseRoles {
+		if role == baseRole {
+			return true
+		}
+	}
+	return false
+}
+
+// IsWildDelegation determines if a role represents a valid wildcard delegation
+// path, i.e. targets/*, targets/foo/*.
+// The wildcard may only appear as the final part of the delegation and must
+// be a whole segment, i.e. targets/foo* is not a valid wildcard delegation.
+func IsWildDelegation(role RoleName) bool {
+	if path.Clean(role.String()) != role.String() {
+		return false
+	}
+	base := role.Parent()
+	if !(IsDelegation(base) || base == CanonicalTargetsRole) {
+		return false
+	}
+	return role[len(role)-2:] == "/*"
+}
+
+// BaseRole is an internal representation of a root/targets/snapshot/timestamp role, with its public keys included
+type BaseRole struct {
+	Keys      map[string]PublicKey
+	Name      RoleName
+	Threshold int
+}
+
+// NewBaseRole creates a new BaseRole object with the provided parameters
+func NewBaseRole(name RoleName, threshold int, keys ...PublicKey) BaseRole {
+	r := BaseRole{
+		Name:      name,
+		Threshold: threshold,
+		Keys:      make(map[string]PublicKey),
+	}
+	for _, k := range keys {
+		r.Keys[k.ID()] = k
+	}
+	return r
+}
+
+// ListKeys retrieves the public keys valid for this role
+func (b BaseRole) ListKeys() KeyList {
+	return listKeys(b.Keys)
+}
+
+// ListKeyIDs retrieves the list of key IDs valid for this role
+func (b BaseRole) ListKeyIDs() []string {
+	return listKeyIDs(b.Keys)
+}
+
+// Equals returns whether this BaseRole equals another BaseRole
+func (b BaseRole) Equals(o BaseRole) bool {
+	if b.Threshold != o.Threshold || b.Name != o.Name || len(b.Keys) != len(o.Keys) {
+		return false
+	}
+
+	for keyID, key := range b.Keys {
+		oKey, ok := o.Keys[keyID]
+		if !ok || key.ID() != oKey.ID() {
+			return false
+		}
+	}
+
+	return true
+}
+
+// DelegationRole is an internal representation of a delegation role, with its public keys included
+type DelegationRole struct {
+	BaseRole
+	Paths []string
+}
+
+func listKeys(keyMap map[string]PublicKey) KeyList {
+	keys := KeyList{}
+	for _, key := range keyMap {
+		keys = append(keys, key)
+	}
+	return keys
+}
+
+func listKeyIDs(keyMap map[string]PublicKey) []string {
+	keyIDs := []string{}
+	for id := range keyMap {
+		keyIDs = append(keyIDs, id)
+	}
+	return keyIDs
+}
+
+// Restrict restricts the paths and path hash prefixes for the passed in delegation role,
+// returning a copy of the role with validated paths as if it was a direct child
+func (d DelegationRole) Restrict(child DelegationRole) (DelegationRole, error) {
+	if !d.IsParentOf(child) {
+		return DelegationRole{}, fmt.Errorf("%s is not a parent of %s", d.Name, child.Name)
+	}
+	return DelegationRole{
+		BaseRole: BaseRole{
+			Keys:      child.Keys,
+			Name:      child.Name,
+			Threshold: child.Threshold,
+		},
+		Paths: RestrictDelegationPathPrefixes(d.Paths, child.Paths),
+	}, nil
+}
+
+// IsParentOf returns whether the passed in delegation role is the direct child of this role,
+// determined by delegation name.
+// Ex: targets/a is a direct parent of targets/a/b, but targets/a is not a direct parent of targets/a/b/c
+func (d DelegationRole) IsParentOf(child DelegationRole) bool {
+	return path.Dir(child.Name.String()) == d.Name.String()
+}
+
+// CheckPaths checks if a given path is valid for the role
+func (d DelegationRole) CheckPaths(path string) bool {
+	return checkPaths(path, d.Paths)
+}
+
+func checkPaths(path string, permitted []string) bool {
+	for _, p := range permitted {
+		if strings.HasPrefix(path, p) {
+			return true
+		}
+	}
+	return false
+}
+
+// RestrictDelegationPathPrefixes returns the list of valid delegationPaths that are prefixed by parentPaths
+func RestrictDelegationPathPrefixes(parentPaths, delegationPaths []string) []string {
+	validPaths := []string{}
+	if len(delegationPaths) == 0 {
+		return validPaths
+	}
+
+	// Validate each individual delegation path
+	for _, delgPath := range delegationPaths {
+		isPrefixed := false
+		for _, parentPath := range parentPaths {
+			if strings.HasPrefix(delgPath, parentPath) {
+				isPrefixed = true
+				break
+			}
+		}
+		// If the delegation path did not match prefix against any parent path, it is not valid
+		if isPrefixed {
+			validPaths = append(validPaths, delgPath)
+		}
+	}
+	return validPaths
+}
+
+// RootRole is a cut down role as it appears in the root.json
+// Eventually should only be used for immediately before and after serialization/deserialization
+type RootRole struct {
+	KeyIDs    []string `json:"keyids"`
+	Threshold int      `json:"threshold"`
+}
+
+// Role is a more verbose role as they appear in targets delegations
+// Eventually should only be used for immediately before and after serialization/deserialization
+type Role struct {
+	RootRole
+	Name  RoleName `json:"name"`
+	Paths []string `json:"paths,omitempty"`
+}
+
+// NewRole creates a new Role object from the given parameters
+func NewRole(name RoleName, threshold int, keyIDs, paths []string) (*Role, error) {
+	if IsDelegation(name) {
+		if len(paths) == 0 {
+			logrus.Debugf("role %s with no Paths will never be able to publish content until one or more are added", name)
+		}
+	}
+	if threshold < 1 {
+		return nil, ErrInvalidRole{Role: name}
+	}
+	if !ValidRole(name) {
+		return nil, ErrInvalidRole{Role: name}
+	}
+	return &Role{
+		RootRole: RootRole{
+			KeyIDs:    keyIDs,
+			Threshold: threshold,
+		},
+		Name:  name,
+		Paths: paths,
+	}, nil
+
+}
+
+// CheckPaths checks if a given path is valid for the role
+func (r Role) CheckPaths(path string) bool {
+	return checkPaths(path, r.Paths)
+}
+
+// AddKeys merges the ids into the current list of role key ids
+func (r *Role) AddKeys(ids []string) {
+	r.KeyIDs = mergeStrSlices(r.KeyIDs, ids)
+}
+
+// AddPaths merges the paths into the current list of role paths
+func (r *Role) AddPaths(paths []string) error {
+	if len(paths) == 0 {
+		return nil
+	}
+	r.Paths = mergeStrSlices(r.Paths, paths)
+	return nil
+}
+
+// RemoveKeys removes the ids from the current list of key ids
+func (r *Role) RemoveKeys(ids []string) {
+	r.KeyIDs = subtractStrSlices(r.KeyIDs, ids)
+}
+
+// RemovePaths removes the paths from the current list of role paths
+func (r *Role) RemovePaths(paths []string) {
+	r.Paths = subtractStrSlices(r.Paths, paths)
+}
+
+func mergeStrSlices(orig, new []string) []string {
+	have := make(map[string]bool)
+	for _, e := range orig {
+		have[e] = true
+	}
+	merged := make([]string, len(orig), len(orig)+len(new))
+	copy(merged, orig)
+	for _, e := range new {
+		if !have[e] {
+			merged = append(merged, e)
+		}
+	}
+	return merged
+}
+
+func subtractStrSlices(orig, remove []string) []string {
+	kill := make(map[string]bool)
+	for _, e := range remove {
+		kill[e] = true
+	}
+	var keep []string
+	for _, e := range orig {
+		if !kill[e] {
+			keep = append(keep, e)
+		}
+	}
+	return keep
+}

vendor/github.com/theupdateframework/notary/tuf/data/root.go

@@ -0,0 +1,171 @@
+package data
+
+import (
+	"fmt"
+
+	"github.com/docker/go/canonical/json"
+)
+
+// SignedRoot is a fully unpacked root.json
+type SignedRoot struct {
+	Signatures []Signature
+	Signed     Root
+	Dirty      bool
+}
+
+// Root is the Signed component of a root.json
+type Root struct {
+	SignedCommon
+	Keys               Keys                   `json:"keys"`
+	Roles              map[RoleName]*RootRole `json:"roles"`
+	ConsistentSnapshot bool                   `json:"consistent_snapshot"`
+}
+
+// isValidRootStructure returns an error, or nil, depending on whether the content of the struct
+// is valid for root metadata.  This does not check signatures or expiry, just that
+// the metadata content is valid.
+func isValidRootStructure(r Root) error {
+	expectedType := TUFTypes[CanonicalRootRole]
+	if r.Type != expectedType {
+		return ErrInvalidMetadata{
+			role: CanonicalRootRole, msg: fmt.Sprintf("expected type %s, not %s", expectedType, r.Type)}
+	}
+
+	if r.Version < 1 {
+		return ErrInvalidMetadata{
+			role: CanonicalRootRole, msg: "version cannot be less than 1"}
+	}
+
+	// all the base roles MUST appear in the root.json - other roles are allowed,
+	// but other than the mirror role (not currently supported) are out of spec
+	for _, roleName := range BaseRoles {
+		roleObj, ok := r.Roles[roleName]
+		if !ok || roleObj == nil {
+			return ErrInvalidMetadata{
+				role: CanonicalRootRole, msg: fmt.Sprintf("missing %s role specification", roleName)}
+		}
+		if err := isValidRootRoleStructure(CanonicalRootRole, roleName, *roleObj, r.Keys); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func isValidRootRoleStructure(metaContainingRole, rootRoleName RoleName, r RootRole, validKeys Keys) error {
+	if r.Threshold < 1 {
+		return ErrInvalidMetadata{
+			role: metaContainingRole,
+			msg:  fmt.Sprintf("invalid threshold specified for %s: %v ", rootRoleName, r.Threshold),
+		}
+	}
+	for _, keyID := range r.KeyIDs {
+		if _, ok := validKeys[keyID]; !ok {
+			return ErrInvalidMetadata{
+				role: metaContainingRole,
+				msg:  fmt.Sprintf("key ID %s specified in %s without corresponding key", keyID, rootRoleName),
+			}
+		}
+	}
+	return nil
+}
+
+// NewRoot initializes a new SignedRoot with a set of keys, roles, and the consistent flag
+func NewRoot(keys map[string]PublicKey, roles map[RoleName]*RootRole, consistent bool) (*SignedRoot, error) {
+	signedRoot := &SignedRoot{
+		Signatures: make([]Signature, 0),
+		Signed: Root{
+			SignedCommon: SignedCommon{
+				Type:    TUFTypes[CanonicalRootRole],
+				Version: 0,
+				Expires: DefaultExpires(CanonicalRootRole),
+			},
+			Keys:               keys,
+			Roles:              roles,
+			ConsistentSnapshot: consistent,
+		},
+		Dirty: true,
+	}
+
+	return signedRoot, nil
+}
+
+// BuildBaseRole returns a copy of a BaseRole using the information in this SignedRoot for the specified role name.
+// Will error for invalid role name or key metadata within this SignedRoot
+func (r SignedRoot) BuildBaseRole(roleName RoleName) (BaseRole, error) {
+	roleData, ok := r.Signed.Roles[roleName]
+	if !ok {
+		return BaseRole{}, ErrInvalidRole{Role: roleName, Reason: "role not found in root file"}
+	}
+	// Get all public keys for the base role from TUF metadata
+	keyIDs := roleData.KeyIDs
+	pubKeys := make(map[string]PublicKey)
+	for _, keyID := range keyIDs {
+		pubKey, ok := r.Signed.Keys[keyID]
+		if !ok {
+			return BaseRole{}, ErrInvalidRole{
+				Role:   roleName,
+				Reason: fmt.Sprintf("key with ID %s was not found in root metadata", keyID),
+			}
+		}
+		pubKeys[keyID] = pubKey
+	}
+
+	return BaseRole{
+		Name:      roleName,
+		Keys:      pubKeys,
+		Threshold: roleData.Threshold,
+	}, nil
+}
+
+// ToSigned partially serializes a SignedRoot for further signing
+func (r SignedRoot) ToSigned() (*Signed, error) {
+	s, err := defaultSerializer.MarshalCanonical(r.Signed)
+	if err != nil {
+		return nil, err
+	}
+	// cast into a json.RawMessage
+	signed := json.RawMessage{}
+	err = signed.UnmarshalJSON(s)
+	if err != nil {
+		return nil, err
+	}
+	sigs := make([]Signature, len(r.Signatures))
+	copy(sigs, r.Signatures)
+	return &Signed{
+		Signatures: sigs,
+		Signed:     &signed,
+	}, nil
+}
+
+// MarshalJSON returns the serialized form of SignedRoot as bytes
+func (r SignedRoot) MarshalJSON() ([]byte, error) {
+	signed, err := r.ToSigned()
+	if err != nil {
+		return nil, err
+	}
+	return defaultSerializer.Marshal(signed)
+}
+
+// RootFromSigned fully unpacks a Signed object into a SignedRoot and ensures
+// that it is a valid SignedRoot
+func RootFromSigned(s *Signed) (*SignedRoot, error) {
+	r := Root{}
+	if s.Signed == nil {
+		return nil, ErrInvalidMetadata{
+			role: CanonicalRootRole,
+			msg:  "root file contained an empty payload",
+		}
+	}
+	if err := defaultSerializer.Unmarshal(*s.Signed, &r); err != nil {
+		return nil, err
+	}
+	if err := isValidRootStructure(r); err != nil {
+		return nil, err
+	}
+	sigs := make([]Signature, len(s.Signatures))
+	copy(sigs, s.Signatures)
+	return &SignedRoot{
+		Signatures: sigs,
+		Signed:     r,
+	}, nil
+}

vendor/github.com/theupdateframework/notary/tuf/data/serializer.go

@@ -0,0 +1,36 @@
+package data
+
+import "github.com/docker/go/canonical/json"
+
+// Serializer is an interface that can marshal and unmarshal TUF data.  This
+// is expected to be a canonical JSON marshaller
+type serializer interface {
+	MarshalCanonical(from interface{}) ([]byte, error)
+	Marshal(from interface{}) ([]byte, error)
+	Unmarshal(from []byte, to interface{}) error
+}
+
+// CanonicalJSON marshals to and from canonical JSON
+type canonicalJSON struct{}
+
+// MarshalCanonical returns the canonical JSON form of a thing
+func (c canonicalJSON) MarshalCanonical(from interface{}) ([]byte, error) {
+	return json.MarshalCanonical(from)
+}
+
+// Marshal returns the regular non-canonical JSON form of a thing
+func (c canonicalJSON) Marshal(from interface{}) ([]byte, error) {
+	return json.Marshal(from)
+}
+
+// Unmarshal unmarshals some JSON bytes
+func (c canonicalJSON) Unmarshal(from []byte, to interface{}) error {
+	return json.Unmarshal(from, to)
+}
+
+// defaultSerializer is a canonical JSON serializer
+var defaultSerializer serializer = canonicalJSON{}
+
+func setDefaultSerializer(s serializer) {
+	defaultSerializer = s
+}

vendor/github.com/theupdateframework/notary/tuf/data/snapshot.go

@@ -0,0 +1,169 @@
+package data
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/docker/go/canonical/json"
+	"github.com/sirupsen/logrus"
+	"github.com/theupdateframework/notary"
+)
+
+// SignedSnapshot is a fully unpacked snapshot.json
+type SignedSnapshot struct {
+	Signatures []Signature
+	Signed     Snapshot
+	Dirty      bool
+}
+
+// Snapshot is the Signed component of a snapshot.json
+type Snapshot struct {
+	SignedCommon
+	Meta Files `json:"meta"`
+}
+
+// IsValidSnapshotStructure returns an error, or nil, depending on whether the content of the
+// struct is valid for snapshot metadata.  This does not check signatures or expiry, just that
+// the metadata content is valid.
+func IsValidSnapshotStructure(s Snapshot) error {
+	expectedType := TUFTypes[CanonicalSnapshotRole]
+	if s.Type != expectedType {
+		return ErrInvalidMetadata{
+			role: CanonicalSnapshotRole, msg: fmt.Sprintf("expected type %s, not %s", expectedType, s.Type)}
+	}
+
+	if s.Version < 1 {
+		return ErrInvalidMetadata{
+			role: CanonicalSnapshotRole, msg: "version cannot be less than one"}
+	}
+
+	for _, file := range []RoleName{CanonicalRootRole, CanonicalTargetsRole} {
+		// Meta is a map of FileMeta, so if the role isn't in the map it returns
+		// an empty FileMeta, which has an empty map, and you can check on keys
+		// from an empty map.
+		//
+		// For now sha256 is required and sha512 is not.
+		if _, ok := s.Meta[file.String()].Hashes[notary.SHA256]; !ok {
+			return ErrInvalidMetadata{
+				role: CanonicalSnapshotRole,
+				msg:  fmt.Sprintf("missing %s sha256 checksum information", file.String()),
+			}
+		}
+		if err := CheckValidHashStructures(s.Meta[file.String()].Hashes); err != nil {
+			return ErrInvalidMetadata{
+				role: CanonicalSnapshotRole,
+				msg:  fmt.Sprintf("invalid %s checksum information, %v", file.String(), err),
+			}
+		}
+	}
+	return nil
+}
+
+// NewSnapshot initializes a SignedSnapshot with a given top level root
+// and targets objects
+func NewSnapshot(root *Signed, targets *Signed) (*SignedSnapshot, error) {
+	logrus.Debug("generating new snapshot...")
+	targetsJSON, err := json.Marshal(targets)
+	if err != nil {
+		logrus.Debug("Error Marshalling Targets")
+		return nil, err
+	}
+	rootJSON, err := json.Marshal(root)
+	if err != nil {
+		logrus.Debug("Error Marshalling Root")
+		return nil, err
+	}
+	rootMeta, err := NewFileMeta(bytes.NewReader(rootJSON), NotaryDefaultHashes...)
+	if err != nil {
+		return nil, err
+	}
+	targetsMeta, err := NewFileMeta(bytes.NewReader(targetsJSON), NotaryDefaultHashes...)
+	if err != nil {
+		return nil, err
+	}
+	return &SignedSnapshot{
+		Signatures: make([]Signature, 0),
+		Signed: Snapshot{
+			SignedCommon: SignedCommon{
+				Type:    TUFTypes[CanonicalSnapshotRole],
+				Version: 0,
+				Expires: DefaultExpires(CanonicalSnapshotRole),
+			},
+			Meta: Files{
+				CanonicalRootRole.String():    rootMeta,
+				CanonicalTargetsRole.String(): targetsMeta,
+			},
+		},
+	}, nil
+}
+
+// ToSigned partially serializes a SignedSnapshot for further signing
+func (sp *SignedSnapshot) ToSigned() (*Signed, error) {
+	s, err := defaultSerializer.MarshalCanonical(sp.Signed)
+	if err != nil {
+		return nil, err
+	}
+	signed := json.RawMessage{}
+	err = signed.UnmarshalJSON(s)
+	if err != nil {
+		return nil, err
+	}
+	sigs := make([]Signature, len(sp.Signatures))
+	copy(sigs, sp.Signatures)
+	return &Signed{
+		Signatures: sigs,
+		Signed:     &signed,
+	}, nil
+}
+
+// AddMeta updates a role in the snapshot with new meta
+func (sp *SignedSnapshot) AddMeta(role RoleName, meta FileMeta) {
+	sp.Signed.Meta[role.String()] = meta
+	sp.Dirty = true
+}
+
+// GetMeta gets the metadata for a particular role, returning an error if it's
+// not found
+func (sp *SignedSnapshot) GetMeta(role RoleName) (*FileMeta, error) {
+	if meta, ok := sp.Signed.Meta[role.String()]; ok {
+		if _, ok := meta.Hashes["sha256"]; ok {
+			return &meta, nil
+		}
+	}
+	return nil, ErrMissingMeta{Role: role.String()}
+}
+
+// DeleteMeta removes a role from the snapshot. If the role doesn't
+// exist in the snapshot, it's a noop.
+func (sp *SignedSnapshot) DeleteMeta(role RoleName) {
+	if _, ok := sp.Signed.Meta[role.String()]; ok {
+		delete(sp.Signed.Meta, role.String())
+		sp.Dirty = true
+	}
+}
+
+// MarshalJSON returns the serialized form of SignedSnapshot as bytes
+func (sp *SignedSnapshot) MarshalJSON() ([]byte, error) {
+	signed, err := sp.ToSigned()
+	if err != nil {
+		return nil, err
+	}
+	return defaultSerializer.Marshal(signed)
+}
+
+// SnapshotFromSigned fully unpacks a Signed object into a SignedSnapshot
+func SnapshotFromSigned(s *Signed) (*SignedSnapshot, error) {
+	sp := Snapshot{}
+	if err := defaultSerializer.Unmarshal(*s.Signed, &sp); err != nil {
+		return nil, err
+	}
+	if err := IsValidSnapshotStructure(sp); err != nil {
+		return nil, err
+	}
+	sigs := make([]Signature, len(s.Signatures))
+	copy(sigs, s.Signatures)
+	return &SignedSnapshot{
+		Signatures: sigs,
+		Signed:     sp,
+	}, nil
+}

vendor/github.com/theupdateframework/notary/tuf/data/targets.go

@@ -0,0 +1,201 @@
+package data
+
+import (
+	"errors"
+	"fmt"
+	"path"
+
+	"github.com/docker/go/canonical/json"
+)
+
+// SignedTargets is a fully unpacked targets.json, or target delegation
+// json file
+type SignedTargets struct {
+	Signatures []Signature
+	Signed     Targets
+	Dirty      bool
+}
+
+// Targets is the Signed components of a targets.json or delegation json file
+type Targets struct {
+	SignedCommon
+	Targets     Files       `json:"targets"`
+	Delegations Delegations `json:"delegations,omitempty"`
+}
+
+// isValidTargetsStructure returns an error, or nil, depending on whether the content of the struct
+// is valid for targets metadata.  This does not check signatures or expiry, just that
+// the metadata content is valid.
+func isValidTargetsStructure(t Targets, roleName RoleName) error {
+	if roleName != CanonicalTargetsRole && !IsDelegation(roleName) {
+		return ErrInvalidRole{Role: roleName}
+	}
+
+	// even if it's a delegated role, the metadata type is "Targets"
+	expectedType := TUFTypes[CanonicalTargetsRole]
+	if t.Type != expectedType {
+		return ErrInvalidMetadata{
+			role: roleName, msg: fmt.Sprintf("expected type %s, not %s", expectedType, t.Type)}
+	}
+
+	if t.Version < 1 {
+		return ErrInvalidMetadata{role: roleName, msg: "version cannot be less than one"}
+	}
+
+	for _, roleObj := range t.Delegations.Roles {
+		if !IsDelegation(roleObj.Name) || path.Dir(roleObj.Name.String()) != roleName.String() {
+			return ErrInvalidMetadata{
+				role: roleName, msg: fmt.Sprintf("delegation role %s invalid", roleObj.Name)}
+		}
+		if err := isValidRootRoleStructure(roleName, roleObj.Name, roleObj.RootRole, t.Delegations.Keys); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// NewTargets initializes a new empty SignedTargets object
+func NewTargets() *SignedTargets {
+	return &SignedTargets{
+		Signatures: make([]Signature, 0),
+		Signed: Targets{
+			SignedCommon: SignedCommon{
+				Type:    TUFTypes["targets"],
+				Version: 0,
+				Expires: DefaultExpires("targets"),
+			},
+			Targets:     make(Files),
+			Delegations: *NewDelegations(),
+		},
+		Dirty: true,
+	}
+}
+
+// GetMeta attempts to find the targets entry for the path. It
+// will return nil in the case of the target not being found.
+func (t SignedTargets) GetMeta(path string) *FileMeta {
+	for p, meta := range t.Signed.Targets {
+		if p == path {
+			return &meta
+		}
+	}
+	return nil
+}
+
+// GetValidDelegations filters the delegation roles specified in the signed targets, and
+// only returns roles that are direct children and restricts their paths
+func (t SignedTargets) GetValidDelegations(parent DelegationRole) []DelegationRole {
+	roles := t.buildDelegationRoles()
+	result := []DelegationRole{}
+	for _, r := range roles {
+		validRole, err := parent.Restrict(r)
+		if err != nil {
+			continue
+		}
+		result = append(result, validRole)
+	}
+	return result
+}
+
+// BuildDelegationRole returns a copy of a DelegationRole using the information in this SignedTargets for the specified role name.
+// Will error for invalid role name or key metadata within this SignedTargets.  Path data is not validated.
+func (t *SignedTargets) BuildDelegationRole(roleName RoleName) (DelegationRole, error) {
+	for _, role := range t.Signed.Delegations.Roles {
+		if role.Name == roleName {
+			pubKeys := make(map[string]PublicKey)
+			for _, keyID := range role.KeyIDs {
+				pubKey, ok := t.Signed.Delegations.Keys[keyID]
+				if !ok {
+					// Couldn't retrieve all keys, so stop walking and return invalid role
+					return DelegationRole{}, ErrInvalidRole{
+						Role:   roleName,
+						Reason: "role lists unknown key " + keyID + " as a signing key",
+					}
+				}
+				pubKeys[keyID] = pubKey
+			}
+			return DelegationRole{
+				BaseRole: BaseRole{
+					Name:      role.Name,
+					Keys:      pubKeys,
+					Threshold: role.Threshold,
+				},
+				Paths: role.Paths,
+			}, nil
+		}
+	}
+	return DelegationRole{}, ErrNoSuchRole{Role: roleName}
+}
+
+// helper function to create DelegationRole structures from all delegations in a SignedTargets,
+// these delegations are read directly from the SignedTargets and not modified or validated
+func (t SignedTargets) buildDelegationRoles() []DelegationRole {
+	var roles []DelegationRole
+	for _, roleData := range t.Signed.Delegations.Roles {
+		delgRole, err := t.BuildDelegationRole(roleData.Name)
+		if err != nil {
+			continue
+		}
+		roles = append(roles, delgRole)
+	}
+	return roles
+}
+
+// AddTarget adds or updates the meta for the given path
+func (t *SignedTargets) AddTarget(path string, meta FileMeta) {
+	t.Signed.Targets[path] = meta
+	t.Dirty = true
+}
+
+// AddDelegation will add a new delegated role with the given keys,
+// ensuring the keys either already exist, or are added to the map
+// of delegation keys
+func (t *SignedTargets) AddDelegation(role *Role, keys []*PublicKey) error {
+	return errors.New("Not Implemented")
+}
+
+// ToSigned partially serializes a SignedTargets for further signing
+func (t *SignedTargets) ToSigned() (*Signed, error) {
+	s, err := defaultSerializer.MarshalCanonical(t.Signed)
+	if err != nil {
+		return nil, err
+	}
+	signed := json.RawMessage{}
+	err = signed.UnmarshalJSON(s)
+	if err != nil {
+		return nil, err
+	}
+	sigs := make([]Signature, len(t.Signatures))
+	copy(sigs, t.Signatures)
+	return &Signed{
+		Signatures: sigs,
+		Signed:     &signed,
+	}, nil
+}
+
+// MarshalJSON returns the serialized form of SignedTargets as bytes
+func (t *SignedTargets) MarshalJSON() ([]byte, error) {
+	signed, err := t.ToSigned()
+	if err != nil {
+		return nil, err
+	}
+	return defaultSerializer.Marshal(signed)
+}
+
+// TargetsFromSigned fully unpacks a Signed object into a SignedTargets, given
+// a role name (so it can validate the SignedTargets object)
+func TargetsFromSigned(s *Signed, roleName RoleName) (*SignedTargets, error) {
+	t := Targets{}
+	if err := defaultSerializer.Unmarshal(*s.Signed, &t); err != nil {
+		return nil, err
+	}
+	if err := isValidTargetsStructure(t, roleName); err != nil {
+		return nil, err
+	}
+	sigs := make([]Signature, len(s.Signatures))
+	copy(sigs, s.Signatures)
+	return &SignedTargets{
+		Signatures: sigs,
+		Signed:     t,
+	}, nil
+}

vendor/github.com/theupdateframework/notary/tuf/data/timestamp.go

@@ -0,0 +1,136 @@
+package data
+
+import (
+	"bytes"
+	"fmt"
+
+	"github.com/docker/go/canonical/json"
+	"github.com/theupdateframework/notary"
+)
+
+// SignedTimestamp is a fully unpacked timestamp.json
+type SignedTimestamp struct {
+	Signatures []Signature
+	Signed     Timestamp
+	Dirty      bool
+}
+
+// Timestamp is the Signed component of a timestamp.json
+type Timestamp struct {
+	SignedCommon
+	Meta Files `json:"meta"`
+}
+
+// IsValidTimestampStructure returns an error, or nil, depending on whether the content of the struct
+// is valid for timestamp metadata.  This does not check signatures or expiry, just that
+// the metadata content is valid.
+func IsValidTimestampStructure(t Timestamp) error {
+	expectedType := TUFTypes[CanonicalTimestampRole]
+	if t.Type != expectedType {
+		return ErrInvalidMetadata{
+			role: CanonicalTimestampRole, msg: fmt.Sprintf("expected type %s, not %s", expectedType, t.Type)}
+	}
+
+	if t.Version < 1 {
+		return ErrInvalidMetadata{
+			role: CanonicalTimestampRole, msg: "version cannot be less than one"}
+	}
+
+	// Meta is a map of FileMeta, so if the role isn't in the map it returns
+	// an empty FileMeta, which has an empty map, and you can check on keys
+	// from an empty map.
+	//
+	// For now sha256 is required and sha512 is not.
+	if _, ok := t.Meta[CanonicalSnapshotRole.String()].Hashes[notary.SHA256]; !ok {
+		return ErrInvalidMetadata{
+			role: CanonicalTimestampRole, msg: "missing snapshot sha256 checksum information"}
+	}
+	if err := CheckValidHashStructures(t.Meta[CanonicalSnapshotRole.String()].Hashes); err != nil {
+		return ErrInvalidMetadata{
+			role: CanonicalTimestampRole, msg: fmt.Sprintf("invalid snapshot checksum information, %v", err)}
+	}
+
+	return nil
+}
+
+// NewTimestamp initializes a timestamp with an existing snapshot
+func NewTimestamp(snapshot *Signed) (*SignedTimestamp, error) {
+	snapshotJSON, err := json.Marshal(snapshot)
+	if err != nil {
+		return nil, err
+	}
+	snapshotMeta, err := NewFileMeta(bytes.NewReader(snapshotJSON), NotaryDefaultHashes...)
+	if err != nil {
+		return nil, err
+	}
+	return &SignedTimestamp{
+		Signatures: make([]Signature, 0),
+		Signed: Timestamp{
+			SignedCommon: SignedCommon{
+				Type:    TUFTypes[CanonicalTimestampRole],
+				Version: 0,
+				Expires: DefaultExpires(CanonicalTimestampRole),
+			},
+			Meta: Files{
+				CanonicalSnapshotRole.String(): snapshotMeta,
+			},
+		},
+	}, nil
+}
+
+// ToSigned partially serializes a SignedTimestamp such that it can
+// be signed
+func (ts *SignedTimestamp) ToSigned() (*Signed, error) {
+	s, err := defaultSerializer.MarshalCanonical(ts.Signed)
+	if err != nil {
+		return nil, err
+	}
+	signed := json.RawMessage{}
+	err = signed.UnmarshalJSON(s)
+	if err != nil {
+		return nil, err
+	}
+	sigs := make([]Signature, len(ts.Signatures))
+	copy(sigs, ts.Signatures)
+	return &Signed{
+		Signatures: sigs,
+		Signed:     &signed,
+	}, nil
+}
+
+// GetSnapshot gets the expected snapshot metadata hashes in the timestamp metadata,
+// or nil if it doesn't exist
+func (ts *SignedTimestamp) GetSnapshot() (*FileMeta, error) {
+	snapshotExpected, ok := ts.Signed.Meta[CanonicalSnapshotRole.String()]
+	if !ok {
+		return nil, ErrMissingMeta{Role: CanonicalSnapshotRole.String()}
+	}
+	return &snapshotExpected, nil
+}
+
+// MarshalJSON returns the serialized form of SignedTimestamp as bytes
+func (ts *SignedTimestamp) MarshalJSON() ([]byte, error) {
+	signed, err := ts.ToSigned()
+	if err != nil {
+		return nil, err
+	}
+	return defaultSerializer.Marshal(signed)
+}
+
+// TimestampFromSigned parsed a Signed object into a fully unpacked
+// SignedTimestamp
+func TimestampFromSigned(s *Signed) (*SignedTimestamp, error) {
+	ts := Timestamp{}
+	if err := defaultSerializer.Unmarshal(*s.Signed, &ts); err != nil {
+		return nil, err
+	}
+	if err := IsValidTimestampStructure(ts); err != nil {
+		return nil, err
+	}
+	sigs := make([]Signature, len(s.Signatures))
+	copy(sigs, s.Signatures)
+	return &SignedTimestamp{
+		Signatures: sigs,
+		Signed:     ts,
+	}, nil
+}

vendor/github.com/theupdateframework/notary/tuf/data/types.go

@@ -0,0 +1,390 @@
+package data
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"crypto/sha512"
+	"crypto/subtle"
+	"encoding/hex"
+	"fmt"
+	"hash"
+	"io"
+	"io/ioutil"
+	"path"
+	"strings"
+	"time"
+
+	"github.com/docker/go/canonical/json"
+	"github.com/sirupsen/logrus"
+	"github.com/theupdateframework/notary"
+)
+
+// GUN is a Globally Unique Name. It is used to identify trust collections.
+// An example usage of this is for container image repositories.
+// For example: myregistry.io/myuser/myimage
+type GUN string
+
+func (g GUN) String() string {
+	return string(g)
+}
+
+// RoleName type for specifying role
+type RoleName string
+
+func (r RoleName) String() string {
+	return string(r)
+}
+
+// Parent provides the parent path role from the provided child role
+func (r RoleName) Parent() RoleName {
+	return RoleName(path.Dir(r.String()))
+}
+
+// MetadataRoleMapToStringMap generates a map string of bytes from a map RoleName of bytes
+func MetadataRoleMapToStringMap(roles map[RoleName][]byte) map[string][]byte {
+	metadata := make(map[string][]byte)
+	for k, v := range roles {
+		metadata[k.String()] = v
+	}
+	return metadata
+}
+
+// NewRoleList generates an array of RoleName objects from a slice of strings
+func NewRoleList(roles []string) []RoleName {
+	var roleNames []RoleName
+	for _, role := range roles {
+		roleNames = append(roleNames, RoleName(role))
+	}
+	return roleNames
+}
+
+// RolesListToStringList generates an array of string objects from a slice of roles
+func RolesListToStringList(roles []RoleName) []string {
+	var roleNames []string
+	for _, role := range roles {
+		roleNames = append(roleNames, role.String())
+	}
+	return roleNames
+}
+
+// SigAlgorithm for types of signatures
+type SigAlgorithm string
+
+func (k SigAlgorithm) String() string {
+	return string(k)
+}
+
+const defaultHashAlgorithm = "sha256"
+
+// NotaryDefaultExpiries is the construct used to configure the default expiry times of
+// the various role files.
+var NotaryDefaultExpiries = map[RoleName]time.Duration{
+	CanonicalRootRole:      notary.NotaryRootExpiry,
+	CanonicalTargetsRole:   notary.NotaryTargetsExpiry,
+	CanonicalSnapshotRole:  notary.NotarySnapshotExpiry,
+	CanonicalTimestampRole: notary.NotaryTimestampExpiry,
+}
+
+// Signature types
+const (
+	EDDSASignature       SigAlgorithm = "eddsa"
+	RSAPSSSignature      SigAlgorithm = "rsapss"
+	RSAPKCS1v15Signature SigAlgorithm = "rsapkcs1v15"
+	ECDSASignature       SigAlgorithm = "ecdsa"
+	PyCryptoSignature    SigAlgorithm = "pycrypto-pkcs#1 pss"
+)
+
+// Key types
+const (
+	ED25519Key   = "ed25519"
+	RSAKey       = "rsa"
+	RSAx509Key   = "rsa-x509"
+	ECDSAKey     = "ecdsa"
+	ECDSAx509Key = "ecdsa-x509"
+)
+
+// TUFTypes is the set of metadata types
+var TUFTypes = map[RoleName]string{
+	CanonicalRootRole:      "Root",
+	CanonicalTargetsRole:   "Targets",
+	CanonicalSnapshotRole:  "Snapshot",
+	CanonicalTimestampRole: "Timestamp",
+}
+
+// ValidTUFType checks if the given type is valid for the role
+func ValidTUFType(typ string, role RoleName) bool {
+	if ValidRole(role) {
+		// All targets delegation roles must have
+		// the valid type is for targets.
+		if role == "" {
+			// role is unknown and does not map to
+			// a type
+			return false
+		}
+		if strings.HasPrefix(role.String(), CanonicalTargetsRole.String()+"/") {
+			role = CanonicalTargetsRole
+		}
+	}
+	// most people will just use the defaults so have this optimal check
+	// first. Do comparison just in case there is some unknown vulnerability
+	// if a key and value in the map differ.
+	if v, ok := TUFTypes[role]; ok {
+		return typ == v
+	}
+	return false
+}
+
+// Signed is the high level, partially deserialized metadata object
+// used to verify signatures before fully unpacking, or to add signatures
+// before fully packing
+type Signed struct {
+	Signed     *json.RawMessage `json:"signed"`
+	Signatures []Signature      `json:"signatures"`
+}
+
+// SignedCommon contains the fields common to the Signed component of all
+// TUF metadata files
+type SignedCommon struct {
+	Type    string    `json:"_type"`
+	Expires time.Time `json:"expires"`
+	Version int       `json:"version"`
+}
+
+// SignedMeta is used in server validation where we only need signatures
+// and common fields
+type SignedMeta struct {
+	Signed     SignedCommon `json:"signed"`
+	Signatures []Signature  `json:"signatures"`
+}
+
+// Signature is a signature on a piece of metadata
+type Signature struct {
+	KeyID     string       `json:"keyid"`
+	Method    SigAlgorithm `json:"method"`
+	Signature []byte       `json:"sig"`
+	IsValid   bool         `json:"-"`
+}
+
+// Files is the map of paths to file meta container in targets and delegations
+// metadata files
+type Files map[string]FileMeta
+
+// Hashes is the map of hash type to digest created for each metadata
+// and target file
+type Hashes map[string][]byte
+
+// NotaryDefaultHashes contains the default supported hash algorithms.
+var NotaryDefaultHashes = []string{notary.SHA256, notary.SHA512}
+
+// FileMeta contains the size and hashes for a metadata or target file. Custom
+// data can be optionally added.
+type FileMeta struct {
+	Length int64            `json:"length"`
+	Hashes Hashes           `json:"hashes"`
+	Custom *json.RawMessage `json:"custom,omitempty"`
+}
+
+// Equals returns true if the other FileMeta object is equivalent to this one
+func (f FileMeta) Equals(o FileMeta) bool {
+	if o.Length != f.Length || len(o.Hashes) != len(f.Hashes) {
+		return false
+	}
+	if f.Custom == nil && o.Custom != nil || f.Custom != nil && o.Custom == nil {
+		return false
+	}
+	// we don't care if these are valid hashes, just that they are equal
+	for key, val := range f.Hashes {
+		if !bytes.Equal(val, o.Hashes[key]) {
+			return false
+		}
+	}
+	if f.Custom == nil && o.Custom == nil {
+		return true
+	}
+	fBytes, err := f.Custom.MarshalJSON()
+	if err != nil {
+		return false
+	}
+	oBytes, err := o.Custom.MarshalJSON()
+	if err != nil {
+		return false
+	}
+	return bytes.Equal(fBytes, oBytes)
+}
+
+// CheckHashes verifies all the checksums specified by the "hashes" of the payload.
+func CheckHashes(payload []byte, name string, hashes Hashes) error {
+	cnt := 0
+
+	// k, v indicate the hash algorithm and the corresponding value
+	for k, v := range hashes {
+		switch k {
+		case notary.SHA256:
+			checksum := sha256.Sum256(payload)
+			if subtle.ConstantTimeCompare(checksum[:], v) == 0 {
+				return ErrMismatchedChecksum{alg: notary.SHA256, name: name, expected: hex.EncodeToString(v)}
+			}
+			cnt++
+		case notary.SHA512:
+			checksum := sha512.Sum512(payload)
+			if subtle.ConstantTimeCompare(checksum[:], v) == 0 {
+				return ErrMismatchedChecksum{alg: notary.SHA512, name: name, expected: hex.EncodeToString(v)}
+			}
+			cnt++
+		}
+	}
+
+	if cnt == 0 {
+		return ErrMissingMeta{Role: name}
+	}
+
+	return nil
+}
+
+// CompareMultiHashes verifies that the two Hashes passed in can represent the same data.
+// This means that both maps must have at least one key defined for which they map, and no conflicts.
+// Note that we check the intersection of map keys, which adds support for non-default hash algorithms in notary
+func CompareMultiHashes(hashes1, hashes2 Hashes) error {
+	// First check if the two hash structures are valid
+	if err := CheckValidHashStructures(hashes1); err != nil {
+		return err
+	}
+	if err := CheckValidHashStructures(hashes2); err != nil {
+		return err
+	}
+	// Check if they have at least one matching hash, and no conflicts
+	cnt := 0
+	for hashAlg, hash1 := range hashes1 {
+
+		hash2, ok := hashes2[hashAlg]
+		if !ok {
+			continue
+		}
+
+		if subtle.ConstantTimeCompare(hash1[:], hash2[:]) == 0 {
+			return fmt.Errorf("mismatched %s checksum", hashAlg)
+		}
+		// If we reached here, we had a match
+		cnt++
+	}
+
+	if cnt == 0 {
+		return fmt.Errorf("at least one matching hash needed")
+	}
+
+	return nil
+}
+
+// CheckValidHashStructures returns an error, or nil, depending on whether
+// the content of the hashes is valid or not.
+func CheckValidHashStructures(hashes Hashes) error {
+	cnt := 0
+
+	for k, v := range hashes {
+		switch k {
+		case notary.SHA256:
+			if len(v) != sha256.Size {
+				return ErrInvalidChecksum{alg: notary.SHA256}
+			}
+			cnt++
+		case notary.SHA512:
+			if len(v) != sha512.Size {
+				return ErrInvalidChecksum{alg: notary.SHA512}
+			}
+			cnt++
+		}
+	}
+
+	if cnt == 0 {
+		return fmt.Errorf("at least one supported hash needed")
+	}
+
+	return nil
+}
+
+// NewFileMeta generates a FileMeta object from the reader, using the
+// hash algorithms provided
+func NewFileMeta(r io.Reader, hashAlgorithms ...string) (FileMeta, error) {
+	if len(hashAlgorithms) == 0 {
+		hashAlgorithms = []string{defaultHashAlgorithm}
+	}
+	hashes := make(map[string]hash.Hash, len(hashAlgorithms))
+	for _, hashAlgorithm := range hashAlgorithms {
+		var h hash.Hash
+		switch hashAlgorithm {
+		case notary.SHA256:
+			h = sha256.New()
+		case notary.SHA512:
+			h = sha512.New()
+		default:
+			return FileMeta{}, fmt.Errorf("Unknown hash algorithm: %s", hashAlgorithm)
+		}
+		hashes[hashAlgorithm] = h
+		r = io.TeeReader(r, h)
+	}
+	n, err := io.Copy(ioutil.Discard, r)
+	if err != nil {
+		return FileMeta{}, err
+	}
+	m := FileMeta{Length: n, Hashes: make(Hashes, len(hashes))}
+	for hashAlgorithm, h := range hashes {
+		m.Hashes[hashAlgorithm] = h.Sum(nil)
+	}
+	return m, nil
+}
+
+// Delegations holds a tier of targets delegations
+type Delegations struct {
+	Keys  Keys    `json:"keys"`
+	Roles []*Role `json:"roles"`
+}
+
+// NewDelegations initializes an empty Delegations object
+func NewDelegations() *Delegations {
+	return &Delegations{
+		Keys:  make(map[string]PublicKey),
+		Roles: make([]*Role, 0),
+	}
+}
+
+// These values are recommended TUF expiry times.
+var defaultExpiryTimes = map[RoleName]time.Duration{
+	CanonicalRootRole:      notary.Year,
+	CanonicalTargetsRole:   90 * notary.Day,
+	CanonicalSnapshotRole:  7 * notary.Day,
+	CanonicalTimestampRole: notary.Day,
+}
+
+// SetDefaultExpiryTimes allows one to change the default expiries.
+func SetDefaultExpiryTimes(times map[RoleName]time.Duration) {
+	for key, value := range times {
+		if _, ok := defaultExpiryTimes[key]; !ok {
+			logrus.Errorf("Attempted to set default expiry for an unknown role: %s", key.String())
+			continue
+		}
+		defaultExpiryTimes[key] = value
+	}
+}
+
+// DefaultExpires gets the default expiry time for the given role
+func DefaultExpires(role RoleName) time.Time {
+	if d, ok := defaultExpiryTimes[role]; ok {
+		return time.Now().Add(d)
+	}
+	var t time.Time
+	return t.UTC().Round(time.Second)
+}
+
+type unmarshalledSignature Signature
+
+// UnmarshalJSON does a custom unmarshalling of the signature JSON
+func (s *Signature) UnmarshalJSON(data []byte) error {
+	uSignature := unmarshalledSignature{}
+	err := json.Unmarshal(data, &uSignature)
+	if err != nil {
+		return err
+	}
+	uSignature.Method = SigAlgorithm(strings.ToLower(string(uSignature.Method)))
+	*s = Signature(uSignature)
+	return nil
+}

vendor/github.com/theupdateframework/notary/tuf/signed/ed25519.go

@@ -0,0 +1,111 @@
+package signed
+
+import (
+	"crypto/rand"
+	"errors"
+
+	"github.com/theupdateframework/notary/trustmanager"
+	"github.com/theupdateframework/notary/tuf/data"
+	"github.com/theupdateframework/notary/tuf/utils"
+)
+
+type edCryptoKey struct {
+	role    data.RoleName
+	privKey data.PrivateKey
+}
+
+// Ed25519 implements a simple in memory cryptosystem for ED25519 keys
+type Ed25519 struct {
+	keys map[string]edCryptoKey
+}
+
+// NewEd25519 initializes a new empty Ed25519 CryptoService that operates
+// entirely in memory
+func NewEd25519() *Ed25519 {
+	return &Ed25519{
+		make(map[string]edCryptoKey),
+	}
+}
+
+// AddKey allows you to add a private key
+func (e *Ed25519) AddKey(role data.RoleName, gun data.GUN, k data.PrivateKey) error {
+	e.addKey(role, k)
+	return nil
+}
+
+// addKey allows you to add a private key
+func (e *Ed25519) addKey(role data.RoleName, k data.PrivateKey) {
+	e.keys[k.ID()] = edCryptoKey{
+		role:    role,
+		privKey: k,
+	}
+}
+
+// RemoveKey deletes a key from the signer
+func (e *Ed25519) RemoveKey(keyID string) error {
+	delete(e.keys, keyID)
+	return nil
+}
+
+// ListKeys returns the list of keys IDs for the role
+func (e *Ed25519) ListKeys(role data.RoleName) []string {
+	keyIDs := make([]string, 0, len(e.keys))
+	for id, edCryptoKey := range e.keys {
+		if edCryptoKey.role == role {
+			keyIDs = append(keyIDs, id)
+		}
+	}
+	return keyIDs
+}
+
+// ListAllKeys returns the map of keys IDs to role
+func (e *Ed25519) ListAllKeys() map[string]data.RoleName {
+	keys := make(map[string]data.RoleName)
+	for id, edKey := range e.keys {
+		keys[id] = edKey.role
+	}
+	return keys
+}
+
+// Create generates a new key and returns the public part
+func (e *Ed25519) Create(role data.RoleName, gun data.GUN, algorithm string) (data.PublicKey, error) {
+	if algorithm != data.ED25519Key {
+		return nil, errors.New("only ED25519 supported by this cryptoservice")
+	}
+
+	private, err := utils.GenerateED25519Key(rand.Reader)
+	if err != nil {
+		return nil, err
+	}
+
+	e.addKey(role, private)
+	return data.PublicKeyFromPrivate(private), nil
+}
+
+// PublicKeys returns a map of public keys for the ids provided, when those IDs are found
+// in the store.
+func (e *Ed25519) PublicKeys(keyIDs ...string) (map[string]data.PublicKey, error) {
+	k := make(map[string]data.PublicKey)
+	for _, keyID := range keyIDs {
+		if edKey, ok := e.keys[keyID]; ok {
+			k[keyID] = data.PublicKeyFromPrivate(edKey.privKey)
+		}
+	}
+	return k, nil
+}
+
+// GetKey returns a single public key based on the ID
+func (e *Ed25519) GetKey(keyID string) data.PublicKey {
+	if privKey, _, err := e.GetPrivateKey(keyID); err == nil {
+		return data.PublicKeyFromPrivate(privKey)
+	}
+	return nil
+}
+
+// GetPrivateKey returns a single private key and role if present, based on the ID
+func (e *Ed25519) GetPrivateKey(keyID string) (data.PrivateKey, data.RoleName, error) {
+	if k, ok := e.keys[keyID]; ok {
+		return k.privKey, k.role, nil
+	}
+	return nil, "", trustmanager.ErrKeyNotFound{KeyID: keyID}
+}

vendor/github.com/theupdateframework/notary/tuf/signed/errors.go

@@ -0,0 +1,98 @@
+package signed
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/theupdateframework/notary/tuf/data"
+)
+
+// ErrInsufficientSignatures - can not create enough signatures on a piece of
+// metadata
+type ErrInsufficientSignatures struct {
+	FoundKeys     int
+	NeededKeys    int
+	MissingKeyIDs []string
+}
+
+func (e ErrInsufficientSignatures) Error() string {
+	candidates := ""
+	if len(e.MissingKeyIDs) > 0 {
+		candidates = fmt.Sprintf(" (%s)", strings.Join(e.MissingKeyIDs, ", "))
+	}
+
+	if e.FoundKeys == 0 {
+		return fmt.Sprintf("signing keys not available: need %d keys from %d possible keys%s",
+			e.NeededKeys, len(e.MissingKeyIDs), candidates)
+	}
+	return fmt.Sprintf("not enough signing keys: found %d of %d needed keys - %d other possible keys%s",
+		e.FoundKeys, e.NeededKeys, len(e.MissingKeyIDs), candidates)
+}
+
+// ErrExpired indicates a piece of metadata has expired
+type ErrExpired struct {
+	Role    data.RoleName
+	Expired string
+}
+
+func (e ErrExpired) Error() string {
+	return fmt.Sprintf("%s expired at %v", e.Role.String(), e.Expired)
+}
+
+// ErrLowVersion indicates the piece of metadata has a version number lower than
+// a version number we're already seen for this role
+type ErrLowVersion struct {
+	Actual  int
+	Current int
+}
+
+func (e ErrLowVersion) Error() string {
+	return fmt.Sprintf("version %d is lower than current version %d", e.Actual, e.Current)
+}
+
+// ErrRoleThreshold indicates we did not validate enough signatures to meet the threshold
+type ErrRoleThreshold struct {
+	Msg string
+}
+
+func (e ErrRoleThreshold) Error() string {
+	if e.Msg == "" {
+		return "valid signatures did not meet threshold"
+	}
+	return e.Msg
+}
+
+// ErrInvalidKeyType indicates the types for the key and signature it's associated with are
+// mismatched. Probably a sign of malicious behaviour
+type ErrInvalidKeyType struct{}
+
+func (e ErrInvalidKeyType) Error() string {
+	return "key type is not valid for signature"
+}
+
+// ErrInvalidKeyID indicates the specified key ID was incorrect for its associated data
+type ErrInvalidKeyID struct{}
+
+func (e ErrInvalidKeyID) Error() string {
+	return "key ID is not valid for key content"
+}
+
+// ErrInvalidKeyLength indicates that while we may support the cipher, the provided
+// key length is not specifically supported, i.e. we support RSA, but not 1024 bit keys
+type ErrInvalidKeyLength struct {
+	msg string
+}
+
+func (e ErrInvalidKeyLength) Error() string {
+	return fmt.Sprintf("key length is not supported: %s", e.msg)
+}
+
+// ErrNoKeys indicates no signing keys were found when trying to sign
+type ErrNoKeys struct {
+	KeyIDs []string
+}
+
+func (e ErrNoKeys) Error() string {
+	return fmt.Sprintf("could not find necessary signing keys, at least one of these keys must be available: %s",
+		strings.Join(e.KeyIDs, ", "))
+}

vendor/github.com/theupdateframework/notary/tuf/signed/interface.go

@@ -0,0 +1,47 @@
+package signed
+
+import "github.com/theupdateframework/notary/tuf/data"
+
+// KeyService provides management of keys locally. It will never
+// accept or provide private keys. Communication between the KeyService
+// and a SigningService happen behind the Create function.
+type KeyService interface {
+	// Create issues a new key pair and is responsible for loading
+	// the private key into the appropriate signing service.
+	Create(role data.RoleName, gun data.GUN, algorithm string) (data.PublicKey, error)
+
+	// AddKey adds a private key to the specified role and gun
+	AddKey(role data.RoleName, gun data.GUN, key data.PrivateKey) error
+
+	// GetKey retrieves the public key if present, otherwise it returns nil
+	GetKey(keyID string) data.PublicKey
+
+	// GetPrivateKey retrieves the private key and role if present and retrievable,
+	// otherwise it returns nil and an error
+	GetPrivateKey(keyID string) (data.PrivateKey, data.RoleName, error)
+
+	// RemoveKey deletes the specified key, and returns an error only if the key
+	// removal fails. If the key doesn't exist, no error should be returned.
+	RemoveKey(keyID string) error
+
+	// ListKeys returns a list of key IDs for the role, or an empty list or
+	// nil if there are no keys.
+	ListKeys(role data.RoleName) []string
+
+	// ListAllKeys returns a map of all available signing key IDs to role, or
+	// an empty map or nil if there are no keys.
+	ListAllKeys() map[string]data.RoleName
+}
+
+// CryptoService is deprecated and all instances of its use should be
+// replaced with KeyService
+type CryptoService interface {
+	KeyService
+}
+
+// Verifier defines an interface for verifying signatures. An implementer
+// of this interface should verify signatures for one and only one
+// signing scheme.
+type Verifier interface {
+	Verify(key data.PublicKey, sig []byte, msg []byte) error
+}

vendor/github.com/theupdateframework/notary/tuf/signed/sign.go

@@ -0,0 +1,114 @@
+package signed
+
+// The Sign function is a choke point for all code paths that do signing.
+// We use this fact to do key ID translation. There are 2 types of key ID:
+//   - Scoped: the key ID based purely on the data that appears in the TUF
+//             files. This may be wrapped by a certificate that scopes the
+//             key to be used in a specific context.
+//   - Canonical: the key ID based purely on the public key bytes. This is
+//             used by keystores to easily identify keys that may be reused
+//             in many scoped locations.
+// Currently these types only differ in the context of Root Keys in Notary
+// for which the root key is wrapped using an x509 certificate.
+
+import (
+	"crypto/rand"
+
+	"github.com/sirupsen/logrus"
+	"github.com/theupdateframework/notary/trustmanager"
+	"github.com/theupdateframework/notary/tuf/data"
+	"github.com/theupdateframework/notary/tuf/utils"
+)
+
+// Sign takes a data.Signed and a cryptoservice containing private keys,
+// calculates and adds at least minSignature signatures using signingKeys the
+// data.Signed.  It will also clean up any signatures that are not in produced
+// by either a signingKey or an otherWhitelistedKey.
+// Note that in most cases, otherWhitelistedKeys should probably be null. They
+// are for keys you don't want to sign with, but you also don't want to remove
+// existing signatures by those keys.  For instance, if you want to call Sign
+// multiple times with different sets of signing keys without undoing removing
+// signatures produced by the previous call to Sign.
+func Sign(service CryptoService, s *data.Signed, signingKeys []data.PublicKey,
+	minSignatures int, otherWhitelistedKeys []data.PublicKey) error {
+
+	logrus.Debugf("sign called with %d/%d required keys", minSignatures, len(signingKeys))
+	signatures := make([]data.Signature, 0, len(s.Signatures)+1)
+	signingKeyIDs := make(map[string]struct{})
+	tufIDs := make(map[string]data.PublicKey)
+
+	privKeys := make(map[string]data.PrivateKey)
+
+	// Get all the private key objects related to the public keys
+	missingKeyIDs := []string{}
+	for _, key := range signingKeys {
+		canonicalID, err := utils.CanonicalKeyID(key)
+		tufIDs[key.ID()] = key
+		if err != nil {
+			return err
+		}
+		k, _, err := service.GetPrivateKey(canonicalID)
+		if err != nil {
+			if _, ok := err.(trustmanager.ErrKeyNotFound); ok {
+				missingKeyIDs = append(missingKeyIDs, canonicalID)
+				continue
+			}
+			return err
+		}
+		privKeys[key.ID()] = k
+	}
+
+	// include the list of otherWhitelistedKeys
+	for _, key := range otherWhitelistedKeys {
+		if _, ok := tufIDs[key.ID()]; !ok {
+			tufIDs[key.ID()] = key
+		}
+	}
+
+	// Check to ensure we have enough signing keys
+	if len(privKeys) < minSignatures {
+		return ErrInsufficientSignatures{FoundKeys: len(privKeys),
+			NeededKeys: minSignatures, MissingKeyIDs: missingKeyIDs}
+	}
+
+	emptyStruct := struct{}{}
+	// Do signing and generate list of signatures
+	for keyID, pk := range privKeys {
+		sig, err := pk.Sign(rand.Reader, *s.Signed, nil)
+		if err != nil {
+			logrus.Debugf("Failed to sign with key: %s. Reason: %v", keyID, err)
+			return err
+		}
+		signingKeyIDs[keyID] = emptyStruct
+		signatures = append(signatures, data.Signature{
+			KeyID:     keyID,
+			Method:    pk.SignatureAlgorithm(),
+			Signature: sig[:],
+		})
+	}
+
+	for i := range s.Signatures {
+		sig := s.Signatures[i]
+		if _, ok := signingKeyIDs[sig.KeyID]; ok {
+			// key is in the set of key IDs for which a signature has been created
+			continue
+		}
+		var (
+			k  data.PublicKey
+			ok bool
+		)
+		if k, ok = tufIDs[sig.KeyID]; !ok {
+			// key is no longer a valid signing key
+			continue
+		}
+		if err := VerifySignature(*s.Signed, &sig, k); err != nil {
+			// signature is no longer valid
+			continue
+		}
+		// keep any signatures that still represent valid keys and are
+		// themselves valid
+		signatures = append(signatures, sig)
+	}
+	s.Signatures = signatures
+	return nil
+}

vendor/github.com/theupdateframework/notary/tuf/signed/verifiers.go

@@ -0,0 +1,264 @@
+package signed
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"crypto/sha256"
+	"crypto/x509"
+	"encoding/pem"
+	"fmt"
+	"math/big"
+
+	"github.com/sirupsen/logrus"
+	"github.com/theupdateframework/notary/tuf/data"
+	"golang.org/x/crypto/ed25519"
+)
+
+const (
+	minRSAKeySizeBit  = 2048 // 2048 bits = 256 bytes
+	minRSAKeySizeByte = minRSAKeySizeBit / 8
+)
+
+// Verifiers serves as a map of all verifiers available on the system and
+// can be injected into a verificationService. For testing and configuration
+// purposes, it will not be used by default.
+var Verifiers = map[data.SigAlgorithm]Verifier{
+	data.RSAPSSSignature:      RSAPSSVerifier{},
+	data.RSAPKCS1v15Signature: RSAPKCS1v15Verifier{},
+	data.PyCryptoSignature:    RSAPyCryptoVerifier{},
+	data.ECDSASignature:       ECDSAVerifier{},
+	data.EDDSASignature:       Ed25519Verifier{},
+}
+
+// Ed25519Verifier used to verify Ed25519 signatures
+type Ed25519Verifier struct{}
+
+// Verify checks that an ed25519 signature is valid
+func (v Ed25519Verifier) Verify(key data.PublicKey, sig []byte, msg []byte) error {
+	if key.Algorithm() != data.ED25519Key {
+		return ErrInvalidKeyType{}
+	}
+	sigBytes := make([]byte, ed25519.SignatureSize)
+	if len(sig) != ed25519.SignatureSize {
+		logrus.Debugf("signature length is incorrect, must be %d, was %d.", ed25519.SignatureSize, len(sig))
+		return ErrInvalid
+	}
+	copy(sigBytes, sig)
+
+	keyBytes := make([]byte, ed25519.PublicKeySize)
+	pub := key.Public()
+	if len(pub) != ed25519.PublicKeySize {
+		logrus.Errorf("public key is incorrect size, must be %d, was %d.", ed25519.PublicKeySize, len(pub))
+		return ErrInvalidKeyLength{msg: fmt.Sprintf("ed25519 public key must be %d bytes.", ed25519.PublicKeySize)}
+	}
+	n := copy(keyBytes, key.Public())
+	if n < ed25519.PublicKeySize {
+		logrus.Errorf("failed to copy the key, must have %d bytes, copied %d bytes.", ed25519.PublicKeySize, n)
+		return ErrInvalid
+	}
+
+	if !ed25519.Verify(ed25519.PublicKey(keyBytes), msg, sigBytes) {
+		logrus.Debugf("failed ed25519 verification")
+		return ErrInvalid
+	}
+	return nil
+}
+
+func verifyPSS(key interface{}, digest, sig []byte) error {
+	rsaPub, ok := key.(*rsa.PublicKey)
+	if !ok {
+		logrus.Debugf("value was not an RSA public key")
+		return ErrInvalid
+	}
+
+	if rsaPub.N.BitLen() < minRSAKeySizeBit {
+		logrus.Debugf("RSA keys less than 2048 bits are not acceptable, provided key has length %d.", rsaPub.N.BitLen())
+		return ErrInvalidKeyLength{msg: fmt.Sprintf("RSA key must be at least %d bits.", minRSAKeySizeBit)}
+	}
+
+	if len(sig) < minRSAKeySizeByte {
+		logrus.Debugf("RSA keys less than 2048 bits are not acceptable, provided signature has length %d.", len(sig))
+		return ErrInvalid
+	}
+
+	opts := rsa.PSSOptions{SaltLength: sha256.Size, Hash: crypto.SHA256}
+	if err := rsa.VerifyPSS(rsaPub, crypto.SHA256, digest[:], sig, &opts); err != nil {
+		logrus.Debugf("failed RSAPSS verification: %s", err)
+		return ErrInvalid
+	}
+	return nil
+}
+
+func getRSAPubKey(key data.PublicKey) (crypto.PublicKey, error) {
+	algorithm := key.Algorithm()
+	var pubKey crypto.PublicKey
+
+	switch algorithm {
+	case data.RSAx509Key:
+		pemCert, _ := pem.Decode([]byte(key.Public()))
+		if pemCert == nil {
+			logrus.Debugf("failed to decode PEM-encoded x509 certificate")
+			return nil, ErrInvalid
+		}
+		cert, err := x509.ParseCertificate(pemCert.Bytes)
+		if err != nil {
+			logrus.Debugf("failed to parse x509 certificate: %s\n", err)
+			return nil, ErrInvalid
+		}
+		pubKey = cert.PublicKey
+	case data.RSAKey:
+		var err error
+		pubKey, err = x509.ParsePKIXPublicKey(key.Public())
+		if err != nil {
+			logrus.Debugf("failed to parse public key: %s\n", err)
+			return nil, ErrInvalid
+		}
+	default:
+		// only accept RSA keys
+		logrus.Debugf("invalid key type for RSAPSS verifier: %s", algorithm)
+		return nil, ErrInvalidKeyType{}
+	}
+
+	return pubKey, nil
+}
+
+// RSAPSSVerifier checks RSASSA-PSS signatures
+type RSAPSSVerifier struct{}
+
+// Verify does the actual check.
+func (v RSAPSSVerifier) Verify(key data.PublicKey, sig []byte, msg []byte) error {
+	// will return err if keytype is not a recognized RSA type
+	pubKey, err := getRSAPubKey(key)
+	if err != nil {
+		return err
+	}
+
+	digest := sha256.Sum256(msg)
+
+	return verifyPSS(pubKey, digest[:], sig)
+}
+
+// RSAPKCS1v15Verifier checks RSA PKCS1v15 signatures
+type RSAPKCS1v15Verifier struct{}
+
+// Verify does the actual verification
+func (v RSAPKCS1v15Verifier) Verify(key data.PublicKey, sig []byte, msg []byte) error {
+	// will return err if keytype is not a recognized RSA type
+	pubKey, err := getRSAPubKey(key)
+	if err != nil {
+		return err
+	}
+	digest := sha256.Sum256(msg)
+
+	rsaPub, ok := pubKey.(*rsa.PublicKey)
+	if !ok {
+		logrus.Debugf("value was not an RSA public key")
+		return ErrInvalid
+	}
+
+	if rsaPub.N.BitLen() < minRSAKeySizeBit {
+		logrus.Debugf("RSA keys less than 2048 bits are not acceptable, provided key has length %d.", rsaPub.N.BitLen())
+		return ErrInvalidKeyLength{msg: fmt.Sprintf("RSA key must be at least %d bits.", minRSAKeySizeBit)}
+	}
+
+	if len(sig) < minRSAKeySizeByte {
+		logrus.Debugf("RSA keys less than 2048 bits are not acceptable, provided signature has length %d.", len(sig))
+		return ErrInvalid
+	}
+
+	if err = rsa.VerifyPKCS1v15(rsaPub, crypto.SHA256, digest[:], sig); err != nil {
+		logrus.Errorf("Failed verification: %s", err.Error())
+		return ErrInvalid
+	}
+	return nil
+}
+
+// RSAPyCryptoVerifier checks RSASSA-PSS signatures
+type RSAPyCryptoVerifier struct{}
+
+// Verify does the actual check.
+// N.B. We have not been able to make this work in a way that is compatible
+// with PyCrypto.
+func (v RSAPyCryptoVerifier) Verify(key data.PublicKey, sig []byte, msg []byte) error {
+	digest := sha256.Sum256(msg)
+	if key.Algorithm() != data.RSAKey {
+		return ErrInvalidKeyType{}
+	}
+
+	k, _ := pem.Decode([]byte(key.Public()))
+	if k == nil {
+		logrus.Debugf("failed to decode PEM-encoded x509 certificate")
+		return ErrInvalid
+	}
+
+	pub, err := x509.ParsePKIXPublicKey(k.Bytes)
+	if err != nil {
+		logrus.Debugf("failed to parse public key: %s\n", err)
+		return ErrInvalid
+	}
+
+	return verifyPSS(pub, digest[:], sig)
+}
+
+// ECDSAVerifier checks ECDSA signatures, decoding the keyType appropriately
+type ECDSAVerifier struct{}
+
+// Verify does the actual check.
+func (v ECDSAVerifier) Verify(key data.PublicKey, sig []byte, msg []byte) error {
+	algorithm := key.Algorithm()
+	var pubKey crypto.PublicKey
+
+	switch algorithm {
+	case data.ECDSAx509Key:
+		pemCert, _ := pem.Decode([]byte(key.Public()))
+		if pemCert == nil {
+			logrus.Debugf("failed to decode PEM-encoded x509 certificate for keyID: %s", key.ID())
+			logrus.Debugf("certificate bytes: %s", string(key.Public()))
+			return ErrInvalid
+		}
+		cert, err := x509.ParseCertificate(pemCert.Bytes)
+		if err != nil {
+			logrus.Debugf("failed to parse x509 certificate: %s\n", err)
+			return ErrInvalid
+		}
+		pubKey = cert.PublicKey
+	case data.ECDSAKey:
+		var err error
+		pubKey, err = x509.ParsePKIXPublicKey(key.Public())
+		if err != nil {
+			logrus.Debugf("Failed to parse private key for keyID: %s, %s\n", key.ID(), err)
+			return ErrInvalid
+		}
+	default:
+		// only accept ECDSA keys.
+		logrus.Debugf("invalid key type for ECDSA verifier: %s", algorithm)
+		return ErrInvalidKeyType{}
+	}
+
+	ecdsaPubKey, ok := pubKey.(*ecdsa.PublicKey)
+	if !ok {
+		logrus.Debugf("value isn't an ECDSA public key")
+		return ErrInvalid
+	}
+
+	sigLength := len(sig)
+	expectedOctetLength := 2 * ((ecdsaPubKey.Params().BitSize + 7) >> 3)
+	if sigLength != expectedOctetLength {
+		logrus.Debugf("signature had an unexpected length")
+		return ErrInvalid
+	}
+
+	rBytes, sBytes := sig[:sigLength/2], sig[sigLength/2:]
+	r := new(big.Int).SetBytes(rBytes)
+	s := new(big.Int).SetBytes(sBytes)
+
+	digest := sha256.Sum256(msg)
+
+	if !ecdsa.Verify(ecdsaPubKey, digest[:], r, s) {
+		logrus.Debugf("failed ECDSA signature validation")
+		return ErrInvalid
+	}
+
+	return nil
+}

vendor/github.com/theupdateframework/notary/tuf/signed/verify.go

@@ -0,0 +1,123 @@
+package signed
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/docker/go/canonical/json"
+	"github.com/sirupsen/logrus"
+	"github.com/theupdateframework/notary/tuf/data"
+	"github.com/theupdateframework/notary/tuf/utils"
+)
+
+// Various basic signing errors
+var (
+	ErrNoSignatures = errors.New("tuf: data has no signatures")
+	ErrInvalid      = errors.New("tuf: signature verification failed")
+	ErrWrongType    = errors.New("tuf: meta file has wrong type")
+)
+
+// IsExpired checks if the given time passed before the present time
+func IsExpired(t time.Time) bool {
+	return t.Before(time.Now())
+}
+
+// VerifyExpiry returns ErrExpired if the metadata is expired
+func VerifyExpiry(s *data.SignedCommon, role data.RoleName) error {
+	if IsExpired(s.Expires) {
+		logrus.Errorf("Metadata for %s expired", role)
+		return ErrExpired{Role: role, Expired: s.Expires.Format("Mon Jan 2 15:04:05 MST 2006")}
+	}
+	return nil
+}
+
+// VerifyVersion returns ErrLowVersion if the metadata version is lower than the min version
+func VerifyVersion(s *data.SignedCommon, minVersion int) error {
+	if s.Version < minVersion {
+		return ErrLowVersion{Actual: s.Version, Current: minVersion}
+	}
+	return nil
+}
+
+// VerifySignatures checks the we have sufficient valid signatures for the given role
+func VerifySignatures(s *data.Signed, roleData data.BaseRole) error {
+	if len(s.Signatures) == 0 {
+		return ErrNoSignatures
+	}
+
+	if roleData.Threshold < 1 {
+		return ErrRoleThreshold{}
+	}
+	logrus.Debugf("%s role has key IDs: %s", roleData.Name, strings.Join(roleData.ListKeyIDs(), ","))
+
+	// remarshal the signed part so we can verify the signature, since the signature has
+	// to be of a canonically marshalled signed object
+	var decoded map[string]interface{}
+	if err := json.Unmarshal(*s.Signed, &decoded); err != nil {
+		return err
+	}
+	msg, err := json.MarshalCanonical(decoded)
+	if err != nil {
+		return err
+	}
+
+	valid := make(map[string]struct{})
+	for i := range s.Signatures {
+		sig := &(s.Signatures[i])
+		logrus.Debug("verifying signature for key ID: ", sig.KeyID)
+		key, ok := roleData.Keys[sig.KeyID]
+		if !ok {
+			logrus.Debugf("continuing b/c keyid lookup was nil: %s\n", sig.KeyID)
+			continue
+		}
+		// Check that the signature key ID actually matches the content ID of the key
+		if key.ID() != sig.KeyID {
+			return ErrInvalidKeyID{}
+		}
+		if err := VerifySignature(msg, sig, key); err != nil {
+			logrus.Debugf("continuing b/c %s", err.Error())
+			continue
+		}
+		valid[sig.KeyID] = struct{}{}
+	}
+	if len(valid) < roleData.Threshold {
+		return ErrRoleThreshold{
+			Msg: fmt.Sprintf("valid signatures did not meet threshold for %s", roleData.Name),
+		}
+	}
+
+	return nil
+}
+
+// VerifySignature checks a single signature and public key against a payload
+// If the signature is verified, the signature's is valid field will actually
+// be mutated to be equal to the boolean true
+func VerifySignature(msg []byte, sig *data.Signature, pk data.PublicKey) error {
+	// method lookup is consistent due to Unmarshal JSON doing lower case for us.
+	method := sig.Method
+	verifier, ok := Verifiers[method]
+	if !ok {
+		return fmt.Errorf("signing method is not supported: %s", sig.Method)
+	}
+
+	if err := verifier.Verify(pk, sig.Signature, msg); err != nil {
+		return fmt.Errorf("signature was invalid")
+	}
+	sig.IsValid = true
+	return nil
+}
+
+// VerifyPublicKeyMatchesPrivateKey checks if the private key and the public keys forms valid key pairs.
+// Supports both x509 certificate PublicKeys and non-certificate PublicKeys
+func VerifyPublicKeyMatchesPrivateKey(privKey data.PrivateKey, pubKey data.PublicKey) error {
+	pubKeyID, err := utils.CanonicalKeyID(pubKey)
+	if err != nil {
+		return fmt.Errorf("could not verify key pair: %v", err)
+	}
+	if privKey == nil || pubKeyID != privKey.ID() {
+		return fmt.Errorf("private key is nil or does not match public key")
+	}
+	return nil
+}

vendor/github.com/theupdateframework/notary/tuf/utils/pkcs8.go

@@ -0,0 +1,341 @@
+// Package utils contains tuf related utility functions however this file is hard
+// forked from https://github.com/youmark/pkcs8 package. It has been further modified
+// based on the requirements of Notary. For converting keys into PKCS#8 format,
+// original package expected *crypto.PrivateKey interface, which then type inferred
+// to either *rsa.PrivateKey or *ecdsa.PrivateKey depending on the need and later
+// converted to ASN.1 DER encoded form, this whole process was superfluous here as
+// keys are already being kept in ASN.1 DER format wrapped in data.PrivateKey
+// structure. With these changes, package has became tightly coupled with notary as
+// most of the method signatures have been updated. Moreover support for ED25519
+// keys has been added as well. License for original package is following:
+//
+// The MIT License (MIT)
+//
+// # Copyright (c) 2014 youmark
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+package utils
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/sha1" // #nosec
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/asn1"
+	"errors"
+	"fmt"
+
+	"golang.org/x/crypto/pbkdf2"
+
+	"github.com/theupdateframework/notary/tuf/data"
+)
+
+// Copy from crypto/x509
+var (
+	oidPublicKeyRSA   = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 1, 1}
+	oidPublicKeyDSA   = asn1.ObjectIdentifier{1, 2, 840, 10040, 4, 1}
+	oidPublicKeyECDSA = asn1.ObjectIdentifier{1, 2, 840, 10045, 2, 1}
+	// crypto/x509 doesn't have support for ED25519
+	// http://www.oid-info.com/get/1.3.6.1.4.1.11591.15.1
+	oidPublicKeyED25519 = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 11591, 15, 1}
+)
+
+// Copy from crypto/x509
+var (
+	oidNamedCurveP224 = asn1.ObjectIdentifier{1, 3, 132, 0, 33}
+	oidNamedCurveP256 = asn1.ObjectIdentifier{1, 2, 840, 10045, 3, 1, 7}
+	oidNamedCurveP384 = asn1.ObjectIdentifier{1, 3, 132, 0, 34}
+	oidNamedCurveP521 = asn1.ObjectIdentifier{1, 3, 132, 0, 35}
+)
+
+// Copy from crypto/x509
+func oidFromNamedCurve(curve elliptic.Curve) (asn1.ObjectIdentifier, bool) {
+	switch curve {
+	case elliptic.P224():
+		return oidNamedCurveP224, true
+	case elliptic.P256():
+		return oidNamedCurveP256, true
+	case elliptic.P384():
+		return oidNamedCurveP384, true
+	case elliptic.P521():
+		return oidNamedCurveP521, true
+	}
+
+	return nil, false
+}
+
+// Unecrypted PKCS8
+var (
+	oidPKCS5PBKDF2 = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 5, 12}
+	oidPBES2       = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 5, 13}
+	oidAES256CBC   = asn1.ObjectIdentifier{2, 16, 840, 1, 101, 3, 4, 1, 42}
+)
+
+type ecPrivateKey struct {
+	Version       int
+	PrivateKey    []byte
+	NamedCurveOID asn1.ObjectIdentifier `asn1:"optional,explicit,tag:0"`
+	PublicKey     asn1.BitString        `asn1:"optional,explicit,tag:1"`
+}
+
+type privateKeyInfo struct {
+	Version             int
+	PrivateKeyAlgorithm []asn1.ObjectIdentifier
+	PrivateKey          []byte
+}
+
+// Encrypted PKCS8
+type pbkdf2Params struct {
+	Salt           []byte
+	IterationCount int
+}
+
+type pbkdf2Algorithms struct {
+	IDPBKDF2     asn1.ObjectIdentifier
+	PBKDF2Params pbkdf2Params
+}
+
+type pbkdf2Encs struct {
+	EncryAlgo asn1.ObjectIdentifier
+	IV        []byte
+}
+
+type pbes2Params struct {
+	KeyDerivationFunc pbkdf2Algorithms
+	EncryptionScheme  pbkdf2Encs
+}
+
+type pbes2Algorithms struct {
+	IDPBES2     asn1.ObjectIdentifier
+	PBES2Params pbes2Params
+}
+
+type encryptedPrivateKeyInfo struct {
+	EncryptionAlgorithm pbes2Algorithms
+	EncryptedData       []byte
+}
+
+// pkcs8 reflects an ASN.1, PKCS#8 PrivateKey.
+// copied from https://github.com/golang/go/blob/964639cc338db650ccadeafb7424bc8ebb2c0f6c/src/crypto/x509/pkcs8.go#L17
+type pkcs8 struct {
+	Version    int
+	Algo       pkix.AlgorithmIdentifier
+	PrivateKey []byte
+}
+
+func parsePKCS8ToTufKey(der []byte) (data.PrivateKey, error) {
+	var key pkcs8
+
+	if _, err := asn1.Unmarshal(der, &key); err != nil {
+		if _, ok := err.(asn1.StructuralError); ok {
+			return nil, errors.New("could not decrypt private key")
+		}
+		return nil, err
+	}
+
+	if key.Algo.Algorithm.Equal(oidPublicKeyED25519) {
+		tufED25519PrivateKey, err := ED25519ToPrivateKey(key.PrivateKey)
+		if err != nil {
+			return nil, fmt.Errorf("could not convert ed25519.PrivateKey to data.PrivateKey: %v", err)
+		}
+
+		return tufED25519PrivateKey, nil
+	}
+
+	privKey, err := x509.ParsePKCS8PrivateKey(der)
+	if err != nil {
+		return nil, err
+	}
+
+	switch priv := privKey.(type) {
+	case *rsa.PrivateKey:
+		tufRSAPrivateKey, err := RSAToPrivateKey(priv)
+		if err != nil {
+			return nil, fmt.Errorf("could not convert rsa.PrivateKey to data.PrivateKey: %v", err)
+		}
+
+		return tufRSAPrivateKey, nil
+	case *ecdsa.PrivateKey:
+		tufECDSAPrivateKey, err := ECDSAToPrivateKey(priv)
+		if err != nil {
+			return nil, fmt.Errorf("could not convert ecdsa.PrivateKey to data.PrivateKey: %v", err)
+		}
+
+		return tufECDSAPrivateKey, nil
+	}
+
+	return nil, errors.New("unsupported key type")
+}
+
+// ParsePKCS8ToTufKey requires PKCS#8 key in DER format and returns data.PrivateKey
+// Password should be provided in case of Encrypted PKCS#8 key, else it should be nil.
+func ParsePKCS8ToTufKey(der []byte, password []byte) (data.PrivateKey, error) {
+	if password == nil {
+		return parsePKCS8ToTufKey(der)
+	}
+
+	var privKey encryptedPrivateKeyInfo
+	if _, err := asn1.Unmarshal(der, &privKey); err != nil {
+		return nil, errors.New("pkcs8: only PKCS #5 v2.0 supported")
+	}
+
+	if !privKey.EncryptionAlgorithm.IDPBES2.Equal(oidPBES2) {
+		return nil, errors.New("pkcs8: only PBES2 supported")
+	}
+
+	if !privKey.EncryptionAlgorithm.PBES2Params.KeyDerivationFunc.IDPBKDF2.Equal(oidPKCS5PBKDF2) {
+		return nil, errors.New("pkcs8: only PBKDF2 supported")
+	}
+
+	encParam := privKey.EncryptionAlgorithm.PBES2Params.EncryptionScheme
+	kdfParam := privKey.EncryptionAlgorithm.PBES2Params.KeyDerivationFunc.PBKDF2Params
+
+	switch {
+	case encParam.EncryAlgo.Equal(oidAES256CBC):
+		iv := encParam.IV
+		salt := kdfParam.Salt
+		iter := kdfParam.IterationCount
+
+		encryptedKey := privKey.EncryptedData
+		symkey := pbkdf2.Key(password, salt, iter, 32, sha1.New)
+		block, err := aes.NewCipher(symkey)
+		if err != nil {
+			return nil, err
+		}
+		mode := cipher.NewCBCDecrypter(block, iv)
+		mode.CryptBlocks(encryptedKey, encryptedKey)
+
+		// no need to explicitly remove padding, as ASN.1 unmarshalling will automatically discard it
+		key, err := parsePKCS8ToTufKey(encryptedKey)
+		if err != nil {
+			return nil, errors.New("pkcs8: incorrect password")
+		}
+
+		return key, nil
+	default:
+		return nil, errors.New("pkcs8: only AES-256-CBC supported")
+	}
+
+}
+
+func convertTUFKeyToPKCS8(priv data.PrivateKey) ([]byte, error) {
+	var pkey privateKeyInfo
+
+	switch priv.Algorithm() {
+	case data.RSAKey, data.RSAx509Key:
+		// Per RFC5958, if publicKey is present, then version is set to v2(1) else version is set to v1(0).
+		// But openssl set to v1 even publicKey is present
+		pkey.Version = 0
+		pkey.PrivateKeyAlgorithm = make([]asn1.ObjectIdentifier, 1)
+		pkey.PrivateKeyAlgorithm[0] = oidPublicKeyRSA
+		pkey.PrivateKey = priv.Private()
+	case data.ECDSAKey, data.ECDSAx509Key:
+		// To extract Curve value, parsing ECDSA key to *ecdsa.PrivateKey
+		eckey, err := x509.ParseECPrivateKey(priv.Private())
+		if err != nil {
+			return nil, err
+		}
+
+		oidNamedCurve, ok := oidFromNamedCurve(eckey.Curve)
+		if !ok {
+			return nil, errors.New("pkcs8: unknown elliptic curve")
+		}
+
+		// Per RFC5958, if publicKey is present, then version is set to v2(1) else version is set to v1(0).
+		// But openssl set to v1 even publicKey is present
+		pkey.Version = 1
+		pkey.PrivateKeyAlgorithm = make([]asn1.ObjectIdentifier, 2)
+		pkey.PrivateKeyAlgorithm[0] = oidPublicKeyECDSA
+		pkey.PrivateKeyAlgorithm[1] = oidNamedCurve
+		pkey.PrivateKey = priv.Private()
+	case data.ED25519Key:
+		pkey.Version = 0
+		pkey.PrivateKeyAlgorithm = make([]asn1.ObjectIdentifier, 1)
+		pkey.PrivateKeyAlgorithm[0] = oidPublicKeyED25519
+		pkey.PrivateKey = priv.Private()
+	default:
+		return nil, fmt.Errorf("algorithm %s not supported", priv.Algorithm())
+	}
+
+	return asn1.Marshal(pkey)
+}
+
+func convertTUFKeyToPKCS8Encrypted(priv data.PrivateKey, password []byte) ([]byte, error) {
+	// Convert private key into PKCS8 format
+	pkey, err := convertTUFKeyToPKCS8(priv)
+	if err != nil {
+		return nil, err
+	}
+
+	// Calculate key from password based on PKCS5 algorithm
+	// Use 8 byte salt, 16 byte IV, and 2048 iteration
+	iter := 2048
+	salt := make([]byte, 8)
+	iv := make([]byte, 16)
+	_, err = rand.Reader.Read(salt)
+	if err != nil {
+		return nil, err
+	}
+
+	_, err = rand.Reader.Read(iv)
+	if err != nil {
+		return nil, err
+	}
+
+	key := pbkdf2.Key(password, salt, iter, 32, sha1.New)
+
+	// Use AES256-CBC mode, pad plaintext with PKCS5 padding scheme
+	padding := aes.BlockSize - len(pkey)%aes.BlockSize
+	if padding > 0 {
+		n := len(pkey)
+		pkey = append(pkey, make([]byte, padding)...)
+		for i := 0; i < padding; i++ {
+			pkey[n+i] = byte(padding)
+		}
+	}
+
+	encryptedKey := make([]byte, len(pkey))
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	mode := cipher.NewCBCEncrypter(block, iv)
+	mode.CryptBlocks(encryptedKey, pkey)
+
+	pbkdf2algo := pbkdf2Algorithms{oidPKCS5PBKDF2, pbkdf2Params{salt, iter}}
+	pbkdf2encs := pbkdf2Encs{oidAES256CBC, iv}
+	pbes2algo := pbes2Algorithms{oidPBES2, pbes2Params{pbkdf2algo, pbkdf2encs}}
+
+	encryptedPkey := encryptedPrivateKeyInfo{pbes2algo, encryptedKey}
+	return asn1.Marshal(encryptedPkey)
+}
+
+// ConvertTUFKeyToPKCS8 converts a private key (data.Private) to PKCS#8 and returns in DER format
+// if password is not nil, it would convert the Private Key to Encrypted PKCS#8.
+func ConvertTUFKeyToPKCS8(priv data.PrivateKey, password []byte) ([]byte, error) {
+	if password == nil {
+		return convertTUFKeyToPKCS8(priv)
+	}
+	return convertTUFKeyToPKCS8Encrypted(priv, password)
+}

vendor/github.com/theupdateframework/notary/tuf/utils/role_sort.go

@@ -0,0 +1,31 @@
+package utils
+
+import (
+	"strings"
+)
+
+// RoleList is a list of roles
+type RoleList []string
+
+// Len returns the length of the list
+func (r RoleList) Len() int {
+	return len(r)
+}
+
+// Less returns true if the item at i should be sorted
+// before the item at j. It's an unstable partial ordering
+// based on the number of segments, separated by "/", in
+// the role name
+func (r RoleList) Less(i, j int) bool {
+	segsI := strings.Split(r[i], "/")
+	segsJ := strings.Split(r[j], "/")
+	if len(segsI) == len(segsJ) {
+		return r[i] < r[j]
+	}
+	return len(segsI) < len(segsJ)
+}
+
+// Swap the items at 2 locations in the list
+func (r RoleList) Swap(i, j int) {
+	r[i], r[j] = r[j], r[i]
+}

vendor/github.com/theupdateframework/notary/tuf/utils/stack.go

@@ -0,0 +1,85 @@
+package utils
+
+import (
+	"fmt"
+	"sync"
+)
+
+// ErrEmptyStack is used when an action that requires some
+// content is invoked and the stack is empty
+type ErrEmptyStack struct {
+	action string
+}
+
+func (err ErrEmptyStack) Error() string {
+	return fmt.Sprintf("attempted to %s with empty stack", err.action)
+}
+
+// ErrBadTypeCast is used by PopX functions when the item
+// cannot be typed to X
+type ErrBadTypeCast struct{}
+
+func (err ErrBadTypeCast) Error() string {
+	return "attempted to do a typed pop and item was not of type"
+}
+
+// Stack is a simple type agnostic stack implementation
+type Stack struct {
+	s []interface{}
+	l sync.Mutex
+}
+
+// NewStack create a new stack
+func NewStack() *Stack {
+	s := &Stack{
+		s: make([]interface{}, 0),
+	}
+	return s
+}
+
+// Push adds an item to the top of the stack.
+func (s *Stack) Push(item interface{}) {
+	s.l.Lock()
+	defer s.l.Unlock()
+	s.s = append(s.s, item)
+}
+
+// Pop removes and returns the top item on the stack, or returns
+// ErrEmptyStack if the stack has no content
+func (s *Stack) Pop() (interface{}, error) {
+	s.l.Lock()
+	defer s.l.Unlock()
+	l := len(s.s)
+	if l > 0 {
+		item := s.s[l-1]
+		s.s = s.s[:l-1]
+		return item, nil
+	}
+	return nil, ErrEmptyStack{action: "Pop"}
+}
+
+// PopString attempts to cast the top item on the stack to the string type.
+// If this succeeds, it removes and returns the top item. If the item
+// is not of the string type, ErrBadTypeCast is returned. If the stack
+// is empty, ErrEmptyStack is returned
+func (s *Stack) PopString() (string, error) {
+	s.l.Lock()
+	defer s.l.Unlock()
+	l := len(s.s)
+	if l > 0 {
+		item := s.s[l-1]
+		if item, ok := item.(string); ok {
+			s.s = s.s[:l-1]
+			return item, nil
+		}
+		return "", ErrBadTypeCast{}
+	}
+	return "", ErrEmptyStack{action: "PopString"}
+}
+
+// Empty returns true if the stack is empty
+func (s *Stack) Empty() bool {
+	s.l.Lock()
+	defer s.l.Unlock()
+	return len(s.s) == 0
+}

vendor/github.com/theupdateframework/notary/tuf/utils/utils.go

@@ -0,0 +1,119 @@
+package utils
+
+import (
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/hex"
+	"fmt"
+	"io"
+
+	"github.com/theupdateframework/notary/tuf/data"
+)
+
+// StrSliceContains checks if the given string appears in the slice
+func StrSliceContains(ss []string, s string) bool {
+	for _, v := range ss {
+		if v == s {
+			return true
+		}
+	}
+	return false
+}
+
+// RoleNameSliceContains checks if the given string appears in the slice
+func RoleNameSliceContains(ss []data.RoleName, s data.RoleName) bool {
+	for _, v := range ss {
+		if v == s {
+			return true
+		}
+	}
+	return false
+}
+
+// RoleNameSliceRemove removes the given RoleName from the slice, returning a new slice
+func RoleNameSliceRemove(ss []data.RoleName, s data.RoleName) []data.RoleName {
+	res := []data.RoleName{}
+	for _, v := range ss {
+		if v != s {
+			res = append(res, v)
+		}
+	}
+	return res
+}
+
+// NoopCloser is a simple Reader wrapper that does nothing when Close is
+// called
+type NoopCloser struct {
+	io.Reader
+}
+
+// Close does nothing for a NoopCloser
+func (nc *NoopCloser) Close() error {
+	return nil
+}
+
+// DoHash returns the digest of d using the hashing algorithm named
+// in alg
+func DoHash(alg string, d []byte) []byte {
+	switch alg {
+	case "sha256":
+		digest := sha256.Sum256(d)
+		return digest[:]
+	case "sha512":
+		digest := sha512.Sum512(d)
+		return digest[:]
+	}
+	return nil
+}
+
+// UnusedDelegationKeys prunes a list of keys, returning those that are no
+// longer in use for a given targets file
+func UnusedDelegationKeys(t data.SignedTargets) []string {
+	// compare ids to all still active key ids in all active roles
+	// with the targets file
+	found := make(map[string]bool)
+	for _, r := range t.Signed.Delegations.Roles {
+		for _, id := range r.KeyIDs {
+			found[id] = true
+		}
+	}
+	var discard []string
+	for id := range t.Signed.Delegations.Keys {
+		if !found[id] {
+			discard = append(discard, id)
+		}
+	}
+	return discard
+}
+
+// RemoveUnusedKeys determines which keys in the slice of IDs are no longer
+// used in the given targets file and removes them from the delegated keys
+// map
+func RemoveUnusedKeys(t *data.SignedTargets) {
+	unusedIDs := UnusedDelegationKeys(*t)
+	for _, id := range unusedIDs {
+		delete(t.Signed.Delegations.Keys, id)
+	}
+}
+
+// FindRoleIndex returns the index of the role named <name> or -1 if no
+// matching role is found.
+func FindRoleIndex(rs []*data.Role, name data.RoleName) int {
+	for i, r := range rs {
+		if r.Name == name {
+			return i
+		}
+	}
+	return -1
+}
+
+// ConsistentName generates the appropriate HTTP URL path for the role,
+// based on whether the repo is marked as consistent. The RemoteStore
+// is responsible for adding file extensions.
+func ConsistentName(role string, hashSHA256 []byte) string {
+	if len(hashSHA256) > 0 {
+		hash := hex.EncodeToString(hashSHA256)
+		return fmt.Sprintf("%s.%s", role, hash)
+	}
+	return role
+}

vendor/github.com/theupdateframework/notary/tuf/utils/x509.go

@@ -0,0 +1,564 @@
+package utils
+
+import (
+	"bytes"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"math/big"
+	"time"
+
+	"github.com/sirupsen/logrus"
+	"github.com/theupdateframework/notary"
+	"github.com/theupdateframework/notary/tuf/data"
+	"golang.org/x/crypto/ed25519"
+)
+
+// CanonicalKeyID returns the ID of the public bytes version of a TUF key.
+// On regular RSA/ECDSA TUF keys, this is just the key ID.  On X509 RSA/ECDSA
+// TUF keys, this is the key ID of the public key part of the key in the leaf cert
+func CanonicalKeyID(k data.PublicKey) (string, error) {
+	if k == nil {
+		return "", errors.New("public key is nil")
+	}
+	switch k.Algorithm() {
+	case data.ECDSAx509Key, data.RSAx509Key:
+		return X509PublicKeyID(k)
+	default:
+		return k.ID(), nil
+	}
+}
+
+// LoadCertFromPEM returns the first certificate found in a bunch of bytes or error
+// if nothing is found. Taken from https://golang.org/src/crypto/x509/cert_pool.go#L85.
+func LoadCertFromPEM(pemBytes []byte) (*x509.Certificate, error) {
+	for len(pemBytes) > 0 {
+		var block *pem.Block
+		block, pemBytes = pem.Decode(pemBytes)
+		if block == nil {
+			return nil, errors.New("no certificates found in PEM data")
+		}
+		if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
+			continue
+		}
+
+		cert, err := x509.ParseCertificate(block.Bytes)
+		if err != nil {
+			continue
+		}
+
+		return cert, nil
+	}
+
+	return nil, errors.New("no certificates found in PEM data")
+}
+
+// X509PublicKeyID returns a public key ID as a string, given a
+// data.PublicKey that contains an X509 Certificate
+func X509PublicKeyID(certPubKey data.PublicKey) (string, error) {
+	// Note that this only loads the first certificate from the public key
+	cert, err := LoadCertFromPEM(certPubKey.Public())
+	if err != nil {
+		return "", err
+	}
+	pubKeyBytes, err := x509.MarshalPKIXPublicKey(cert.PublicKey)
+	if err != nil {
+		return "", err
+	}
+
+	var key data.PublicKey
+	switch certPubKey.Algorithm() {
+	case data.ECDSAx509Key:
+		key = data.NewECDSAPublicKey(pubKeyBytes)
+	case data.RSAx509Key:
+		key = data.NewRSAPublicKey(pubKeyBytes)
+	}
+
+	return key.ID(), nil
+}
+
+func parseLegacyPrivateKey(block *pem.Block, passphrase string) (data.PrivateKey, error) {
+	var privKeyBytes []byte
+	var err error
+	if x509.IsEncryptedPEMBlock(block) {
+		privKeyBytes, err = x509.DecryptPEMBlock(block, []byte(passphrase))
+		if err != nil {
+			return nil, errors.New("could not decrypt private key")
+		}
+	} else {
+		privKeyBytes = block.Bytes
+	}
+
+	switch block.Type {
+	case "RSA PRIVATE KEY":
+		rsaPrivKey, err := x509.ParsePKCS1PrivateKey(privKeyBytes)
+		if err != nil {
+			return nil, fmt.Errorf("could not parse DER encoded key: %v", err)
+		}
+
+		tufRSAPrivateKey, err := RSAToPrivateKey(rsaPrivKey)
+		if err != nil {
+			return nil, fmt.Errorf("could not convert rsa.PrivateKey to data.PrivateKey: %v", err)
+		}
+
+		return tufRSAPrivateKey, nil
+	case "EC PRIVATE KEY":
+		ecdsaPrivKey, err := x509.ParseECPrivateKey(privKeyBytes)
+		if err != nil {
+			return nil, fmt.Errorf("could not parse DER encoded private key: %v", err)
+		}
+
+		tufECDSAPrivateKey, err := ECDSAToPrivateKey(ecdsaPrivKey)
+		if err != nil {
+			return nil, fmt.Errorf("could not convert ecdsa.PrivateKey to data.PrivateKey: %v", err)
+		}
+
+		return tufECDSAPrivateKey, nil
+	case "ED25519 PRIVATE KEY":
+		// We serialize ED25519 keys by concatenating the private key
+		// to the public key and encoding with PEM. See the
+		// ED25519ToPrivateKey function.
+		tufECDSAPrivateKey, err := ED25519ToPrivateKey(privKeyBytes)
+		if err != nil {
+			return nil, fmt.Errorf("could not convert ecdsa.PrivateKey to data.PrivateKey: %v", err)
+		}
+
+		return tufECDSAPrivateKey, nil
+
+	default:
+		return nil, fmt.Errorf("unsupported key type %q", block.Type)
+	}
+}
+
+// ParsePEMPrivateKey returns a data.PrivateKey from a PEM encoded private key. It
+// supports PKCS#8 as well as RSA/ECDSA (PKCS#1) only in non-FIPS mode and
+// attempts to decrypt using the passphrase, if encrypted.
+func ParsePEMPrivateKey(pemBytes []byte, passphrase string) (data.PrivateKey, error) {
+	return parsePEMPrivateKey(pemBytes, passphrase, notary.FIPSEnabled())
+}
+
+func parsePEMPrivateKey(pemBytes []byte, passphrase string, fips bool) (data.PrivateKey, error) {
+	block, _ := pem.Decode(pemBytes)
+	if block == nil {
+		return nil, errors.New("no valid private key found")
+	}
+
+	switch block.Type {
+	case "RSA PRIVATE KEY", "EC PRIVATE KEY", "ED25519 PRIVATE KEY":
+		if fips {
+			return nil, fmt.Errorf("%s not supported in FIPS mode", block.Type)
+		}
+		return parseLegacyPrivateKey(block, passphrase)
+	case "ENCRYPTED PRIVATE KEY", "PRIVATE KEY":
+		if passphrase == "" {
+			return ParsePKCS8ToTufKey(block.Bytes, nil)
+		}
+		return ParsePKCS8ToTufKey(block.Bytes, []byte(passphrase))
+	default:
+		return nil, fmt.Errorf("unsupported key type %q", block.Type)
+	}
+}
+
+// CertToPEM is a utility function returns a PEM encoded x509 Certificate
+func CertToPEM(cert *x509.Certificate) []byte {
+	pemCert := pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: cert.Raw})
+
+	return pemCert
+}
+
+// CertChainToPEM is a utility function returns a PEM encoded chain of x509 Certificates, in the order they are passed
+func CertChainToPEM(certChain []*x509.Certificate) ([]byte, error) {
+	var pemBytes bytes.Buffer
+	for _, cert := range certChain {
+		if err := pem.Encode(&pemBytes, &pem.Block{Type: "CERTIFICATE", Bytes: cert.Raw}); err != nil {
+			return nil, err
+		}
+	}
+	return pemBytes.Bytes(), nil
+}
+
+// LoadCertFromFile loads the first certificate from the file provided. The
+// data is expected to be PEM Encoded and contain one of more certificates
+// with PEM type "CERTIFICATE"
+func LoadCertFromFile(filename string) (*x509.Certificate, error) {
+	certs, err := LoadCertBundleFromFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	return certs[0], nil
+}
+
+// LoadCertBundleFromFile loads certificates from the []byte provided. The
+// data is expected to be PEM Encoded and contain one of more certificates
+// with PEM type "CERTIFICATE"
+func LoadCertBundleFromFile(filename string) ([]*x509.Certificate, error) {
+	b, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+
+	return LoadCertBundleFromPEM(b)
+}
+
+// LoadCertBundleFromPEM loads certificates from the []byte provided. The
+// data is expected to be PEM Encoded and contain one of more certificates
+// with PEM type "CERTIFICATE"
+func LoadCertBundleFromPEM(pemBytes []byte) ([]*x509.Certificate, error) {
+	certificates := []*x509.Certificate{}
+	var block *pem.Block
+	block, pemBytes = pem.Decode(pemBytes)
+	for ; block != nil; block, pemBytes = pem.Decode(pemBytes) {
+		if block.Type == "CERTIFICATE" {
+			cert, err := x509.ParseCertificate(block.Bytes)
+			if err != nil {
+				return nil, err
+			}
+			certificates = append(certificates, cert)
+		} else {
+			return nil, fmt.Errorf("invalid pem block type: %s", block.Type)
+		}
+	}
+
+	if len(certificates) == 0 {
+		return nil, fmt.Errorf("no valid certificates found")
+	}
+
+	return certificates, nil
+}
+
+// GetLeafCerts parses a list of x509 Certificates and returns all of them
+// that aren't CA
+func GetLeafCerts(certs []*x509.Certificate) []*x509.Certificate {
+	var leafCerts []*x509.Certificate
+	for _, cert := range certs {
+		if cert.IsCA {
+			continue
+		}
+		leafCerts = append(leafCerts, cert)
+	}
+	return leafCerts
+}
+
+// GetIntermediateCerts parses a list of x509 Certificates and returns all of the
+// ones marked as a CA, to be used as intermediates
+func GetIntermediateCerts(certs []*x509.Certificate) []*x509.Certificate {
+	var intCerts []*x509.Certificate
+	for _, cert := range certs {
+		if cert.IsCA {
+			intCerts = append(intCerts, cert)
+		}
+	}
+	return intCerts
+}
+
+// ParsePEMPublicKey returns a data.PublicKey from a PEM encoded public key or certificate.
+func ParsePEMPublicKey(pubKeyBytes []byte) (data.PublicKey, error) {
+	pemBlock, _ := pem.Decode(pubKeyBytes)
+	if pemBlock == nil {
+		return nil, errors.New("no valid public key found")
+	}
+
+	switch pemBlock.Type {
+	case "CERTIFICATE":
+		cert, err := x509.ParseCertificate(pemBlock.Bytes)
+		if err != nil {
+			return nil, fmt.Errorf("could not parse provided certificate: %v", err)
+		}
+		err = ValidateCertificate(cert, true)
+		if err != nil {
+			return nil, fmt.Errorf("invalid certificate: %v", err)
+		}
+		return CertToKey(cert), nil
+	case "PUBLIC KEY":
+		keyType, err := keyTypeForPublicKey(pemBlock.Bytes)
+		if err != nil {
+			return nil, err
+		}
+		return data.NewPublicKey(keyType, pemBlock.Bytes), nil
+	default:
+		return nil, fmt.Errorf("unsupported PEM block type %q, expected CERTIFICATE or PUBLIC KEY", pemBlock.Type)
+	}
+}
+
+func keyTypeForPublicKey(pubKeyBytes []byte) (string, error) {
+	pub, err := x509.ParsePKIXPublicKey(pubKeyBytes)
+	if err != nil {
+		return "", fmt.Errorf("unable to parse pem encoded public key: %v", err)
+	}
+	switch pub.(type) {
+	case *ecdsa.PublicKey:
+		return data.ECDSAKey, nil
+	case *rsa.PublicKey:
+		return data.RSAKey, nil
+	}
+	return "", fmt.Errorf("unknown public key format")
+}
+
+// ValidateCertificate returns an error if the certificate is not valid for notary
+// Currently this is only ensuring the public key has a large enough modulus if RSA,
+// using a non SHA1 signature algorithm, and an optional time expiry check
+func ValidateCertificate(c *x509.Certificate, checkExpiry bool) error {
+	if (c.NotBefore).After(c.NotAfter) {
+		return fmt.Errorf("certificate validity window is invalid")
+	}
+	// Can't have SHA1 sig algorithm
+	if c.SignatureAlgorithm == x509.SHA1WithRSA || c.SignatureAlgorithm == x509.DSAWithSHA1 || c.SignatureAlgorithm == x509.ECDSAWithSHA1 {
+		return fmt.Errorf("certificate with CN %s uses invalid SHA1 signature algorithm", c.Subject.CommonName)
+	}
+	// If we have an RSA key, make sure it's long enough
+	if c.PublicKeyAlgorithm == x509.RSA {
+		rsaKey, ok := c.PublicKey.(*rsa.PublicKey)
+		if !ok {
+			return fmt.Errorf("unable to parse RSA public key")
+		}
+		if rsaKey.N.BitLen() < notary.MinRSABitSize {
+			return fmt.Errorf("RSA bit length is too short")
+		}
+	}
+	if checkExpiry {
+		now := time.Now()
+		tomorrow := now.AddDate(0, 0, 1)
+		// Give one day leeway on creation "before" time, check "after" against today
+		if (tomorrow).Before(c.NotBefore) || now.After(c.NotAfter) {
+			return data.ErrCertExpired{CN: c.Subject.CommonName}
+		}
+		// If this certificate is expiring within 6 months, put out a warning
+		if (c.NotAfter).Before(time.Now().AddDate(0, 6, 0)) {
+			logrus.Warnf("certificate with CN %s is near expiry", c.Subject.CommonName)
+		}
+	}
+	return nil
+}
+
+// GenerateKey returns a new private key using the provided algorithm or an
+// error detailing why the key could not be generated
+func GenerateKey(algorithm string) (data.PrivateKey, error) {
+	switch algorithm {
+	case data.ECDSAKey:
+		return GenerateECDSAKey(rand.Reader)
+	case data.ED25519Key:
+		return GenerateED25519Key(rand.Reader)
+	}
+	return nil, fmt.Errorf("private key type not supported for key generation: %s", algorithm)
+}
+
+// RSAToPrivateKey converts an rsa.Private key to a TUF data.PrivateKey type
+func RSAToPrivateKey(rsaPrivKey *rsa.PrivateKey) (data.PrivateKey, error) {
+	// Get a DER-encoded representation of the PublicKey
+	rsaPubBytes, err := x509.MarshalPKIXPublicKey(&rsaPrivKey.PublicKey)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal public key: %v", err)
+	}
+
+	// Get a DER-encoded representation of the PrivateKey
+	rsaPrivBytes := x509.MarshalPKCS1PrivateKey(rsaPrivKey)
+
+	pubKey := data.NewRSAPublicKey(rsaPubBytes)
+	return data.NewRSAPrivateKey(pubKey, rsaPrivBytes)
+}
+
+// GenerateECDSAKey generates an ECDSA Private key and returns a TUF PrivateKey
+func GenerateECDSAKey(random io.Reader) (data.PrivateKey, error) {
+	ecdsaPrivKey, err := ecdsa.GenerateKey(elliptic.P256(), random)
+	if err != nil {
+		return nil, err
+	}
+
+	tufPrivKey, err := ECDSAToPrivateKey(ecdsaPrivKey)
+	if err != nil {
+		return nil, err
+	}
+
+	logrus.Debugf("generated ECDSA key with keyID: %s", tufPrivKey.ID())
+
+	return tufPrivKey, nil
+}
+
+// GenerateED25519Key generates an ED25519 private key and returns a TUF
+// PrivateKey. The serialization format we use is just the public key bytes
+// followed by the private key bytes
+func GenerateED25519Key(random io.Reader) (data.PrivateKey, error) {
+	pub, priv, err := ed25519.GenerateKey(random)
+	if err != nil {
+		return nil, err
+	}
+
+	var serialized [ed25519.PublicKeySize + ed25519.PrivateKeySize]byte
+	copy(serialized[:], pub[:])
+	copy(serialized[ed25519.PublicKeySize:], priv[:])
+
+	tufPrivKey, err := ED25519ToPrivateKey(serialized[:])
+	if err != nil {
+		return nil, err
+	}
+
+	logrus.Debugf("generated ED25519 key with keyID: %s", tufPrivKey.ID())
+
+	return tufPrivKey, nil
+}
+
+// ECDSAToPrivateKey converts an ecdsa.Private key to a TUF data.PrivateKey type
+func ECDSAToPrivateKey(ecdsaPrivKey *ecdsa.PrivateKey) (data.PrivateKey, error) {
+	// Get a DER-encoded representation of the PublicKey
+	ecdsaPubBytes, err := x509.MarshalPKIXPublicKey(&ecdsaPrivKey.PublicKey)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal public key: %v", err)
+	}
+
+	// Get a DER-encoded representation of the PrivateKey
+	ecdsaPrivKeyBytes, err := x509.MarshalECPrivateKey(ecdsaPrivKey)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal private key: %v", err)
+	}
+
+	pubKey := data.NewECDSAPublicKey(ecdsaPubBytes)
+	return data.NewECDSAPrivateKey(pubKey, ecdsaPrivKeyBytes)
+}
+
+// ED25519ToPrivateKey converts a serialized ED25519 key to a TUF
+// data.PrivateKey type
+func ED25519ToPrivateKey(privKeyBytes []byte) (data.PrivateKey, error) {
+	if len(privKeyBytes) != ed25519.PublicKeySize+ed25519.PrivateKeySize {
+		return nil, errors.New("malformed ed25519 private key")
+	}
+
+	pubKey := data.NewED25519PublicKey(privKeyBytes[:ed25519.PublicKeySize])
+	return data.NewED25519PrivateKey(*pubKey, privKeyBytes)
+}
+
+// ExtractPrivateKeyAttributes extracts role and gun values from private key bytes
+func ExtractPrivateKeyAttributes(pemBytes []byte) (data.RoleName, data.GUN, error) {
+	return extractPrivateKeyAttributes(pemBytes, notary.FIPSEnabled())
+}
+
+func extractPrivateKeyAttributes(pemBytes []byte, fips bool) (data.RoleName, data.GUN, error) {
+	block, _ := pem.Decode(pemBytes)
+	if block == nil {
+		return "", "", errors.New("PEM block is empty")
+	}
+
+	switch block.Type {
+	case "RSA PRIVATE KEY", "EC PRIVATE KEY", "ED25519 PRIVATE KEY":
+		if fips {
+			return "", "", fmt.Errorf("%s not supported in FIPS mode", block.Type)
+		}
+	case "PRIVATE KEY", "ENCRYPTED PRIVATE KEY":
+		// do nothing for PKCS#8 keys
+	default:
+		return "", "", errors.New("unknown key format")
+	}
+	return data.RoleName(block.Headers["role"]), data.GUN(block.Headers["gun"]), nil
+}
+
+// ConvertPrivateKeyToPKCS8 converts a data.PrivateKey to PKCS#8 Format
+func ConvertPrivateKeyToPKCS8(key data.PrivateKey, role data.RoleName, gun data.GUN, passphrase string) ([]byte, error) {
+	var (
+		err       error
+		der       []byte
+		blockType = "PRIVATE KEY"
+	)
+
+	if passphrase == "" {
+		der, err = ConvertTUFKeyToPKCS8(key, nil)
+	} else {
+		blockType = "ENCRYPTED PRIVATE KEY"
+		der, err = ConvertTUFKeyToPKCS8(key, []byte(passphrase))
+	}
+	if err != nil {
+		return nil, fmt.Errorf("unable to convert to PKCS8 key")
+	}
+
+	headers := make(map[string]string)
+	if role != "" {
+		headers["role"] = role.String()
+	}
+
+	if gun != "" {
+		headers["gun"] = gun.String()
+	}
+
+	return pem.EncodeToMemory(&pem.Block{Bytes: der, Type: blockType, Headers: headers}), nil
+}
+
+// CertToKey transforms a single input certificate into its corresponding
+// PublicKey
+func CertToKey(cert *x509.Certificate) data.PublicKey {
+	block := pem.Block{Type: "CERTIFICATE", Bytes: cert.Raw}
+	pemdata := pem.EncodeToMemory(&block)
+
+	switch cert.PublicKeyAlgorithm {
+	case x509.RSA:
+		return data.NewRSAx509PublicKey(pemdata)
+	case x509.ECDSA:
+		return data.NewECDSAx509PublicKey(pemdata)
+	default:
+		logrus.Debugf("Unknown key type parsed from certificate: %v", cert.PublicKeyAlgorithm)
+		return nil
+	}
+}
+
+// CertsToKeys transforms each of the input certificate chains into its corresponding
+// PublicKey
+func CertsToKeys(leafCerts map[string]*x509.Certificate, intCerts map[string][]*x509.Certificate) map[string]data.PublicKey {
+	keys := make(map[string]data.PublicKey)
+	for id, leafCert := range leafCerts {
+		if key, err := CertBundleToKey(leafCert, intCerts[id]); err == nil {
+			keys[key.ID()] = key
+		}
+	}
+	return keys
+}
+
+// CertBundleToKey creates a TUF key from a leaf certs and a list of
+// intermediates
+func CertBundleToKey(leafCert *x509.Certificate, intCerts []*x509.Certificate) (data.PublicKey, error) {
+	certBundle := []*x509.Certificate{leafCert}
+	certBundle = append(certBundle, intCerts...)
+	certChainPEM, err := CertChainToPEM(certBundle)
+	if err != nil {
+		return nil, err
+	}
+	var newKey data.PublicKey
+	// Use the leaf cert's public key algorithm for typing
+	switch leafCert.PublicKeyAlgorithm {
+	case x509.RSA:
+		newKey = data.NewRSAx509PublicKey(certChainPEM)
+	case x509.ECDSA:
+		newKey = data.NewECDSAx509PublicKey(certChainPEM)
+	default:
+		logrus.Debugf("Unknown key type parsed from certificate: %v", leafCert.PublicKeyAlgorithm)
+		return nil, x509.ErrUnsupportedAlgorithm
+	}
+	return newKey, nil
+}
+
+// NewCertificate returns an X509 Certificate following a template, given a Common Name and validity interval.
+func NewCertificate(commonName string, startTime, endTime time.Time) (*x509.Certificate, error) {
+	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
+
+	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
+	if err != nil {
+		return nil, fmt.Errorf("failed to generate new certificate: %v", err)
+	}
+
+	return &x509.Certificate{
+		SerialNumber: serialNumber,
+		Subject: pkix.Name{
+			CommonName: commonName,
+		},
+		NotBefore: startTime,
+		NotAfter:  endTime,
+
+		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageCodeSigning},
+		BasicConstraintsValid: true,
+	}, nil
+}

vendor/github.com/theupdateframework/notary/tuf/validation/errors.go

@@ -0,0 +1,126 @@
+package validation
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// VALIDATION ERRORS
+
+// ErrValidation represents a general validation error
+type ErrValidation struct {
+	Msg string
+}
+
+func (err ErrValidation) Error() string {
+	return fmt.Sprintf("An error occurred during validation: %s", err.Msg)
+}
+
+// ErrBadHierarchy represents missing metadata.  Currently: a missing snapshot
+// at this current time. When delegations are implemented it will also
+// represent a missing delegation parent
+type ErrBadHierarchy struct {
+	Missing string
+	Msg     string
+}
+
+func (err ErrBadHierarchy) Error() string {
+	return fmt.Sprintf("Metadata hierarchy is incomplete: %s", err.Msg)
+}
+
+// ErrBadRoot represents a failure validating the root
+type ErrBadRoot struct {
+	Msg string
+}
+
+func (err ErrBadRoot) Error() string {
+	return fmt.Sprintf("The root metadata is invalid: %s", err.Msg)
+}
+
+// ErrBadTargets represents a failure to validate a targets (incl delegations)
+type ErrBadTargets struct {
+	Msg string
+}
+
+func (err ErrBadTargets) Error() string {
+	return fmt.Sprintf("The targets metadata is invalid: %s", err.Msg)
+}
+
+// ErrBadSnapshot represents a failure to validate the snapshot
+type ErrBadSnapshot struct {
+	Msg string
+}
+
+func (err ErrBadSnapshot) Error() string {
+	return fmt.Sprintf("The snapshot metadata is invalid: %s", err.Msg)
+}
+
+// END VALIDATION ERRORS
+
+// SerializableError is a struct that can be used to serialize an error as JSON
+type SerializableError struct {
+	Name  string
+	Error error
+}
+
+// UnmarshalJSON attempts to unmarshal the error into the right type
+func (s *SerializableError) UnmarshalJSON(text []byte) (err error) {
+	var x struct{ Name string }
+	err = json.Unmarshal(text, &x)
+	if err != nil {
+		return
+	}
+	var theError error
+	switch x.Name {
+	case "ErrValidation":
+		var e struct{ Error ErrValidation }
+		err = json.Unmarshal(text, &e)
+		theError = e.Error
+	case "ErrBadHierarchy":
+		var e struct{ Error ErrBadHierarchy }
+		err = json.Unmarshal(text, &e)
+		theError = e.Error
+	case "ErrBadRoot":
+		var e struct{ Error ErrBadRoot }
+		err = json.Unmarshal(text, &e)
+		theError = e.Error
+	case "ErrBadTargets":
+		var e struct{ Error ErrBadTargets }
+		err = json.Unmarshal(text, &e)
+		theError = e.Error
+	case "ErrBadSnapshot":
+		var e struct{ Error ErrBadSnapshot }
+		err = json.Unmarshal(text, &e)
+		theError = e.Error
+	default:
+		err = fmt.Errorf("do not know how to unmarshal %s", x.Name)
+		return
+	}
+	if err != nil {
+		return
+	}
+	s.Name = x.Name
+	s.Error = theError
+	return nil
+}
+
+// NewSerializableError serializes one of the above errors into JSON
+func NewSerializableError(err error) (*SerializableError, error) {
+	// make sure it's one of our errors
+	var name string
+	switch err.(type) {
+	case ErrValidation:
+		name = "ErrValidation"
+	case ErrBadHierarchy:
+		name = "ErrBadHierarchy"
+	case ErrBadRoot:
+		name = "ErrBadRoot"
+	case ErrBadTargets:
+		name = "ErrBadTargets"
+	case ErrBadSnapshot:
+		name = "ErrBadSnapshot"
+	default:
+		return nil, fmt.Errorf("does not support serializing non-validation errors")
+	}
+	return &SerializableError{Name: name, Error: err}, nil
+}