Golang SerializeSymmetricallyEncrypted Beispiele

Golang SerializeSymmetricallyEncrypted - 2 Beispiele gefunden. Dies sind die am besten bewerteten Golang Beispiele für die github.com/keybase/go-crypto/openpgp/packet.SerializeSymmetricallyEncrypted, die aus Open Source-Projekten extrahiert wurden. Sie können Beispiele bewerten, um die Qualität der Beispiele zu verbessern.
Beispiel #1
0
// SymmetricallyEncrypt acts like gpg -c: it encrypts a file with a passphrase.
// The resulting WriteCloser must be closed after the contents of the file have
// been written.
// If config is nil, sensible defaults will be used.
func SymmetricallyEncrypt(ciphertext io.Writer, passphrase []byte, hints *FileHints, config *packet.Config) (plaintext io.WriteCloser, err error) {
	if hints == nil {
		hints = &FileHints{}
	}

	key, err := packet.SerializeSymmetricKeyEncrypted(ciphertext, passphrase, config)
	if err != nil {
		return
	}
	w, err := packet.SerializeSymmetricallyEncrypted(ciphertext, config.Cipher(), key, config)
	if err != nil {
		return
	}

	literaldata := w
	if algo := config.Compression(); algo != packet.CompressionNone {
		var compConfig *packet.CompressionConfig
		if config != nil {
			compConfig = config.CompressionConfig
		}
		literaldata, err = packet.SerializeCompressed(w, algo, compConfig)
		if err != nil {
			return
		}
	}

	var epochSeconds uint32
	if !hints.ModTime.IsZero() {
		epochSeconds = uint32(hints.ModTime.Unix())
	}
	return packet.SerializeLiteral(literaldata, hints.IsBinary, hints.FileName, epochSeconds)
}
Beispiel #2
0
// Encrypt encrypts a message to a number of recipients and, optionally, signs
// it. hints contains optional information, that is also encrypted, that aids
// the recipients in processing the message. The resulting WriteCloser must
// be closed after the contents of the file have been written.
// If config is nil, sensible defaults will be used.
func Encrypt(ciphertext io.Writer, to []*Entity, signed *Entity, hints *FileHints, config *packet.Config) (plaintext io.WriteCloser, err error) {
	var signer *packet.PrivateKey
	if signed != nil {
		signKey, ok := signed.signingKey(config.Now())
		if !ok {
			return nil, errors.InvalidArgumentError("no valid signing keys")
		}
		signer = signKey.PrivateKey
		if signer == nil {
			return nil, errors.InvalidArgumentError("no private key in signing key")
		}
		if signer.Encrypted {
			return nil, errors.InvalidArgumentError("signing key must be decrypted")
		}
	}

	// These are the possible ciphers that we'll use for the message.
	candidateCiphers := []uint8{
		uint8(packet.CipherAES128),
		uint8(packet.CipherAES256),
		uint8(packet.CipherCAST5),
	}
	// These are the possible hash functions that we'll use for the signature.
	candidateHashes := []uint8{
		hashToHashId(crypto.SHA256),
		hashToHashId(crypto.SHA512),
		hashToHashId(crypto.SHA1),
		hashToHashId(crypto.RIPEMD160),
	}

	// If no preferences were specified, assume something safe and reasonable.
	defaultCiphers := []uint8{
		uint8(packet.CipherAES128),
		uint8(packet.CipherAES192),
		uint8(packet.CipherAES256),
		uint8(packet.CipherCAST5),
	}

	defaultHashes := []uint8{
		hashToHashId(crypto.SHA256),
		hashToHashId(crypto.SHA512),
		hashToHashId(crypto.RIPEMD160),
	}

	encryptKeys := make([]Key, len(to))
	for i := range to {
		var ok bool
		encryptKeys[i], ok = to[i].encryptionKey(config.Now())
		if !ok {
			return nil, errors.InvalidArgumentError("cannot encrypt a message to key id " + strconv.FormatUint(to[i].PrimaryKey.KeyId, 16) + " because it has no encryption keys")
		}

		sig := to[i].primaryIdentity().SelfSignature

		preferredSymmetric := sig.PreferredSymmetric
		if len(preferredSymmetric) == 0 {
			preferredSymmetric = defaultCiphers
		}
		preferredHashes := sig.PreferredHash
		if len(preferredHashes) == 0 {
			preferredHashes = defaultHashes
		}
		candidateCiphers = intersectPreferences(candidateCiphers, preferredSymmetric)
		candidateHashes = intersectPreferences(candidateHashes, preferredHashes)
	}

	if len(candidateCiphers) == 0 {
		return nil, errors.InvalidArgumentError("cannot encrypt because recipient set shares no common ciphers")
	}
	if len(candidateHashes) == 0 {
		return nil, errors.InvalidArgumentError("cannot encrypt because recipient set shares no common hashes")
	}

	cipher := packet.CipherFunction(candidateCiphers[0])
	// If the cipher specifed by config is a candidate, we'll use that.
	configuredCipher := config.Cipher()
	for _, c := range candidateCiphers {
		cipherFunc := packet.CipherFunction(c)
		if cipherFunc == configuredCipher {
			cipher = cipherFunc
			break
		}
	}

	var hash crypto.Hash
	for _, hashId := range candidateHashes {
		if h, ok := s2k.HashIdToHash(hashId); ok && h.Available() {
			hash = h
			break
		}
	}

	// If the hash specified by config is a candidate, we'll use that.
	if configuredHash := config.Hash(); configuredHash.Available() {
		for _, hashId := range candidateHashes {
			if h, ok := s2k.HashIdToHash(hashId); ok && h == configuredHash {
				hash = h
				break
			}
		}
	}

	if hash == 0 {
		hashId := candidateHashes[0]
		name, ok := s2k.HashIdToString(hashId)
		if !ok {
			name = "#" + strconv.Itoa(int(hashId))
		}
		return nil, errors.InvalidArgumentError("cannot encrypt because no candidate hash functions are compiled in. (Wanted " + name + " in this case.)")
	}

	symKey := make([]byte, cipher.KeySize())
	if _, err := io.ReadFull(config.Random(), symKey); err != nil {
		return nil, err
	}

	for _, key := range encryptKeys {
		if err := packet.SerializeEncryptedKey(ciphertext, key.PublicKey, cipher, symKey, config); err != nil {
			return nil, err
		}
	}

	encryptedData, err := packet.SerializeSymmetricallyEncrypted(ciphertext, cipher, symKey, config)
	if err != nil {
		return
	}

	if signer != nil {
		ops := &packet.OnePassSignature{
			SigType:    packet.SigTypeBinary,
			Hash:       hash,
			PubKeyAlgo: signer.PubKeyAlgo,
			KeyId:      signer.KeyId,
			IsLast:     true,
		}
		if err := ops.Serialize(encryptedData); err != nil {
			return nil, err
		}
	}

	if hints == nil {
		hints = &FileHints{}
	}

	w := encryptedData
	if signer != nil {
		// If we need to write a signature packet after the literal
		// data then we need to stop literalData from closing
		// encryptedData.
		w = noOpCloser{encryptedData}

	}
	var epochSeconds uint32
	if !hints.ModTime.IsZero() {
		epochSeconds = uint32(hints.ModTime.Unix())
	}
	literalData, err := packet.SerializeLiteral(w, hints.IsBinary, hints.FileName, epochSeconds)
	if err != nil {
		return nil, err
	}

	if signer != nil {
		return signatureWriter{encryptedData, literalData, hash, hash.New(), signer, config}, nil
	}
	return literalData, nil
}