diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/openpgp/packet/symmetric_key_encrypted.go')
-rw-r--r-- | vendor/golang.org/x/crypto/openpgp/packet/symmetric_key_encrypted.go | 155 |
1 files changed, 0 insertions, 155 deletions
diff --git a/vendor/golang.org/x/crypto/openpgp/packet/symmetric_key_encrypted.go b/vendor/golang.org/x/crypto/openpgp/packet/symmetric_key_encrypted.go deleted file mode 100644 index 744c2d2..0000000 --- a/vendor/golang.org/x/crypto/openpgp/packet/symmetric_key_encrypted.go +++ /dev/null @@ -1,155 +0,0 @@ -// 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 ( - "bytes" - "crypto/cipher" - "io" - "strconv" - - "golang.org/x/crypto/openpgp/errors" - "golang.org/x/crypto/openpgp/s2k" -) - -// This is the largest session key that we'll support. Since no 512-bit cipher -// has even been seriously used, this is comfortably large. -const maxSessionKeySizeInBytes = 64 - -// SymmetricKeyEncrypted represents a passphrase protected session key. See RFC -// 4880, section 5.3. -type SymmetricKeyEncrypted struct { - CipherFunc CipherFunction - s2k func(out, in []byte) - encryptedKey []byte -} - -const symmetricKeyEncryptedVersion = 4 - -func (ske *SymmetricKeyEncrypted) parse(r io.Reader) error { - // RFC 4880, section 5.3. - var buf [2]byte - if _, err := readFull(r, buf[:]); err != nil { - return err - } - if buf[0] != symmetricKeyEncryptedVersion { - return errors.UnsupportedError("SymmetricKeyEncrypted version") - } - ske.CipherFunc = CipherFunction(buf[1]) - - if ske.CipherFunc.KeySize() == 0 { - return errors.UnsupportedError("unknown cipher: " + strconv.Itoa(int(buf[1]))) - } - - var err error - ske.s2k, err = s2k.Parse(r) - if err != nil { - return err - } - - encryptedKey := make([]byte, maxSessionKeySizeInBytes) - // The session key may follow. We just have to try and read to find - // out. If it exists then we limit it to maxSessionKeySizeInBytes. - n, err := readFull(r, encryptedKey) - if err != nil && err != io.ErrUnexpectedEOF { - return err - } - - if n != 0 { - if n == maxSessionKeySizeInBytes { - return errors.UnsupportedError("oversized encrypted session key") - } - ske.encryptedKey = encryptedKey[:n] - } - - return nil -} - -// Decrypt attempts to decrypt an encrypted session key and returns the key and -// the cipher to use when decrypting a subsequent Symmetrically Encrypted Data -// packet. -func (ske *SymmetricKeyEncrypted) Decrypt(passphrase []byte) ([]byte, CipherFunction, error) { - key := make([]byte, ske.CipherFunc.KeySize()) - ske.s2k(key, passphrase) - - if len(ske.encryptedKey) == 0 { - return key, ske.CipherFunc, nil - } - - // the IV is all zeros - iv := make([]byte, ske.CipherFunc.blockSize()) - c := cipher.NewCFBDecrypter(ske.CipherFunc.new(key), iv) - plaintextKey := make([]byte, len(ske.encryptedKey)) - c.XORKeyStream(plaintextKey, ske.encryptedKey) - cipherFunc := CipherFunction(plaintextKey[0]) - if cipherFunc.blockSize() == 0 { - return nil, ske.CipherFunc, errors.UnsupportedError("unknown cipher: " + strconv.Itoa(int(cipherFunc))) - } - plaintextKey = plaintextKey[1:] - if l, cipherKeySize := len(plaintextKey), cipherFunc.KeySize(); l != cipherFunc.KeySize() { - return nil, cipherFunc, errors.StructuralError("length of decrypted key (" + strconv.Itoa(l) + ") " + - "not equal to cipher keysize (" + strconv.Itoa(cipherKeySize) + ")") - } - return plaintextKey, cipherFunc, nil -} - -// SerializeSymmetricKeyEncrypted serializes a symmetric key packet to w. The -// packet contains a random session key, encrypted by a key derived from the -// given passphrase. The session key is returned and must be passed to -// SerializeSymmetricallyEncrypted. -// If config is nil, sensible defaults will be used. -func SerializeSymmetricKeyEncrypted(w io.Writer, passphrase []byte, config *Config) (key []byte, err error) { - cipherFunc := config.Cipher() - keySize := cipherFunc.KeySize() - if keySize == 0 { - return nil, errors.UnsupportedError("unknown cipher: " + strconv.Itoa(int(cipherFunc))) - } - - s2kBuf := new(bytes.Buffer) - keyEncryptingKey := make([]byte, keySize) - // s2k.Serialize salts and stretches the passphrase, and writes the - // resulting key to keyEncryptingKey and the s2k descriptor to s2kBuf. - err = s2k.Serialize(s2kBuf, keyEncryptingKey, config.Random(), passphrase, &s2k.Config{Hash: config.Hash(), S2KCount: config.PasswordHashIterations()}) - if err != nil { - return - } - s2kBytes := s2kBuf.Bytes() - - packetLength := 2 /* header */ + len(s2kBytes) + 1 /* cipher type */ + keySize - err = serializeHeader(w, packetTypeSymmetricKeyEncrypted, packetLength) - if err != nil { - return - } - - var buf [2]byte - buf[0] = symmetricKeyEncryptedVersion - buf[1] = byte(cipherFunc) - _, err = w.Write(buf[:]) - if err != nil { - return - } - _, err = w.Write(s2kBytes) - if err != nil { - return - } - - sessionKey := make([]byte, keySize) - _, err = io.ReadFull(config.Random(), sessionKey) - if err != nil { - return - } - iv := make([]byte, cipherFunc.blockSize()) - c := cipher.NewCFBEncrypter(cipherFunc.new(keyEncryptingKey), iv) - encryptedCipherAndKey := make([]byte, keySize+1) - c.XORKeyStream(encryptedCipherAndKey, buf[1:]) - c.XORKeyStream(encryptedCipherAndKey[1:], sessionKey) - _, err = w.Write(encryptedCipherAndKey) - if err != nil { - return - } - - key = sessionKey - return -} |