chore: vendor

vendor/github.com/ProtonMail/go-crypto/openpgp/packet/symmetrically_encrypted.go

@@ -0,0 +1,90 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package packet
+
+import (
+	"io"
+
+	"github.com/ProtonMail/go-crypto/openpgp/errors"
+)
+
+const aeadSaltSize = 32
+
+// SymmetricallyEncrypted represents a symmetrically encrypted byte string. The
+// encrypted Contents will consist of more OpenPGP packets. See RFC 4880,
+// sections 5.7 and 5.13.
+type SymmetricallyEncrypted struct {
+	Version            int
+	Contents           io.Reader // contains tag for version 2
+	IntegrityProtected bool      // If true it is type 18 (with MDC or AEAD). False is packet type 9
+
+	// Specific to version 1
+	prefix []byte
+
+	// Specific to version 2
+	Cipher        CipherFunction
+	Mode          AEADMode
+	ChunkSizeByte byte
+	Salt          [aeadSaltSize]byte
+}
+
+const (
+	symmetricallyEncryptedVersionMdc  = 1
+	symmetricallyEncryptedVersionAead = 2
+)
+
+func (se *SymmetricallyEncrypted) parse(r io.Reader) error {
+	if se.IntegrityProtected {
+		// See RFC 4880, section 5.13.
+		var buf [1]byte
+		_, err := readFull(r, buf[:])
+		if err != nil {
+			return err
+		}
+
+		switch buf[0] {
+		case symmetricallyEncryptedVersionMdc:
+			se.Version = symmetricallyEncryptedVersionMdc
+		case symmetricallyEncryptedVersionAead:
+			se.Version = symmetricallyEncryptedVersionAead
+			if err := se.parseAead(r); err != nil {
+				return err
+			}
+		default:
+			return errors.UnsupportedError("unknown SymmetricallyEncrypted version")
+		}
+	}
+	se.Contents = r
+	return nil
+}
+
+// Decrypt returns a ReadCloser, from which the decrypted Contents of the
+// packet can be read. An incorrect key will only be detected after trying
+// to decrypt the entire data.
+func (se *SymmetricallyEncrypted) Decrypt(c CipherFunction, key []byte) (io.ReadCloser, error) {
+	if se.Version == symmetricallyEncryptedVersionAead {
+		return se.decryptAead(key)
+	}
+
+	return se.decryptMdc(c, key)
+}
+
+// SerializeSymmetricallyEncrypted serializes a symmetrically encrypted packet
+// to w and returns a WriteCloser to which the to-be-encrypted packets can be
+// written.
+// If config is nil, sensible defaults will be used.
+func SerializeSymmetricallyEncrypted(w io.Writer, c CipherFunction, aeadSupported bool, cipherSuite CipherSuite, key []byte, config *Config) (Contents io.WriteCloser, err error) {
+	writeCloser := noOpCloser{w}
+	ciphertext, err := serializeStreamHeader(writeCloser, packetTypeSymmetricallyEncryptedIntegrityProtected)
+	if err != nil {
+		return
+	}
+
+	if aeadSupported {
+		return serializeSymmetricallyEncryptedAead(ciphertext, cipherSuite, config.AEADConfig.ChunkSizeByte(), config.Random(), key)
+	}
+
+	return serializeSymmetricallyEncryptedMdc(ciphertext, c, key, config)
+}