chore: make deps, go mod vendor

vendor/github.com/ProtonMail/go-crypto/openpgp/ed448/ed448.go

@@ -0,0 +1,119 @@
+// Package ed448 implements the ed448 signature algorithm for OpenPGP
+// as defined in the Open PGP crypto refresh.
+package ed448
+
+import (
+	"crypto/subtle"
+	"io"
+
+	"github.com/ProtonMail/go-crypto/openpgp/errors"
+	ed448lib "github.com/cloudflare/circl/sign/ed448"
+)
+
+const (
+	// PublicKeySize is the size, in bytes, of public keys in this package.
+	PublicKeySize = ed448lib.PublicKeySize
+	// SeedSize is the size, in bytes, of private key seeds.
+	// The private key representation used by RFC 8032.
+	SeedSize = ed448lib.SeedSize
+	// SignatureSize is the size, in bytes, of signatures generated and verified by this package.
+	SignatureSize = ed448lib.SignatureSize
+)
+
+type PublicKey struct {
+	// Point represents the elliptic curve point of the public key.
+	Point []byte
+}
+
+type PrivateKey struct {
+	PublicKey
+	// Key the private key representation by RFC 8032,
+	// encoded as seed | public key point.
+	Key []byte
+}
+
+// NewPublicKey creates a new empty ed448 public key.
+func NewPublicKey() *PublicKey {
+	return &PublicKey{}
+}
+
+// NewPrivateKey creates a new empty private key referencing the public key.
+func NewPrivateKey(key PublicKey) *PrivateKey {
+	return &PrivateKey{
+		PublicKey: key,
+	}
+}
+
+// Seed returns the ed448 private key secret seed.
+// The private key representation by RFC 8032.
+func (pk *PrivateKey) Seed() []byte {
+	return pk.Key[:SeedSize]
+}
+
+// MarshalByteSecret returns the underlying seed of the private key.
+func (pk *PrivateKey) MarshalByteSecret() []byte {
+	return pk.Seed()
+}
+
+// UnmarshalByteSecret computes the private key from the secret seed
+// and stores it in the private key object.
+func (sk *PrivateKey) UnmarshalByteSecret(seed []byte) error {
+	sk.Key = ed448lib.NewKeyFromSeed(seed)
+	return nil
+}
+
+// GenerateKey generates a fresh private key with the provided randomness source.
+func GenerateKey(rand io.Reader) (*PrivateKey, error) {
+	publicKey, privateKey, err := ed448lib.GenerateKey(rand)
+	if err != nil {
+		return nil, err
+	}
+	privateKeyOut := new(PrivateKey)
+	privateKeyOut.PublicKey.Point = publicKey[:]
+	privateKeyOut.Key = privateKey[:]
+	return privateKeyOut, nil
+}
+
+// Sign signs a message with the ed448 algorithm.
+// priv MUST be a valid key! Check this with Validate() before use.
+func Sign(priv *PrivateKey, message []byte) ([]byte, error) {
+	// Ed448 is used with the empty string as a context string.
+	// See https://datatracker.ietf.org/doc/html/draft-ietf-openpgp-crypto-refresh-08#section-13.7
+	return ed448lib.Sign(priv.Key, message, ""), nil
+}
+
+// Verify verifies a ed448 signature
+func Verify(pub *PublicKey, message []byte, signature []byte) bool {
+	// Ed448 is used with the empty string as a context string.
+	// See https://datatracker.ietf.org/doc/html/draft-ietf-openpgp-crypto-refresh-08#section-13.7
+	return ed448lib.Verify(pub.Point, message, signature, "")
+}
+
+// Validate checks if the ed448 private key is valid
+func Validate(priv *PrivateKey) error {
+	expectedPrivateKey := ed448lib.NewKeyFromSeed(priv.Seed())
+	if subtle.ConstantTimeCompare(priv.Key, expectedPrivateKey) == 0 {
+		return errors.KeyInvalidError("ed448: invalid ed448 secret")
+	}
+	if subtle.ConstantTimeCompare(priv.PublicKey.Point, expectedPrivateKey[SeedSize:]) == 0 {
+		return errors.KeyInvalidError("ed448: invalid ed448 public key")
+	}
+	return nil
+}
+
+// ENCODING/DECODING signature:
+
+// WriteSignature encodes and writes an ed448 signature to writer.
+func WriteSignature(writer io.Writer, signature []byte) error {
+	_, err := writer.Write(signature)
+	return err
+}
+
+// ReadSignature decodes an ed448 signature from a reader.
+func ReadSignature(reader io.Reader) ([]byte, error) {
+	signature := make([]byte, SignatureSize)
+	if _, err := io.ReadFull(reader, signature); err != nil {
+		return nil, err
+	}
+	return signature, nil
+}