--- /dev/null
+// 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 openpgp
+
+import (
+ "crypto"
+ "hash"
+ "io"
+ "strconv"
+ "time"
+
+ "golang.org/x/crypto/openpgp/armor"
+ "golang.org/x/crypto/openpgp/errors"
+ "golang.org/x/crypto/openpgp/packet"
+ "golang.org/x/crypto/openpgp/s2k"
+)
+
+// DetachSign signs message with the private key from signer (which must
+// already have been decrypted) and writes the signature to w.
+// If config is nil, sensible defaults will be used.
+func DetachSign(w io.Writer, signer *Entity, message io.Reader, config *packet.Config) error {
+ return detachSign(w, signer, message, packet.SigTypeBinary, config)
+}
+
+// ArmoredDetachSign signs message with the private key from signer (which
+// must already have been decrypted) and writes an armored signature to w.
+// If config is nil, sensible defaults will be used.
+func ArmoredDetachSign(w io.Writer, signer *Entity, message io.Reader, config *packet.Config) (err error) {
+ return armoredDetachSign(w, signer, message, packet.SigTypeBinary, config)
+}
+
+// DetachSignText signs message (after canonicalising the line endings) with
+// the private key from signer (which must already have been decrypted) and
+// writes the signature to w.
+// If config is nil, sensible defaults will be used.
+func DetachSignText(w io.Writer, signer *Entity, message io.Reader, config *packet.Config) error {
+ return detachSign(w, signer, message, packet.SigTypeText, config)
+}
+
+// ArmoredDetachSignText signs message (after canonicalising the line endings)
+// with the private key from signer (which must already have been decrypted)
+// and writes an armored signature to w.
+// If config is nil, sensible defaults will be used.
+func ArmoredDetachSignText(w io.Writer, signer *Entity, message io.Reader, config *packet.Config) error {
+ return armoredDetachSign(w, signer, message, packet.SigTypeText, config)
+}
+
+func armoredDetachSign(w io.Writer, signer *Entity, message io.Reader, sigType packet.SignatureType, config *packet.Config) (err error) {
+ out, err := armor.Encode(w, SignatureType, nil)
+ if err != nil {
+ return
+ }
+ err = detachSign(out, signer, message, sigType, config)
+ if err != nil {
+ return
+ }
+ return out.Close()
+}
+
+func detachSign(w io.Writer, signer *Entity, message io.Reader, sigType packet.SignatureType, config *packet.Config) (err error) {
+ if signer.PrivateKey == nil {
+ return errors.InvalidArgumentError("signing key doesn't have a private key")
+ }
+ if signer.PrivateKey.Encrypted {
+ return errors.InvalidArgumentError("signing key is encrypted")
+ }
+
+ sig := new(packet.Signature)
+ sig.SigType = sigType
+ sig.PubKeyAlgo = signer.PrivateKey.PubKeyAlgo
+ sig.Hash = config.Hash()
+ sig.CreationTime = config.Now()
+ sig.IssuerKeyId = &signer.PrivateKey.KeyId
+
+ h, wrappedHash, err := hashForSignature(sig.Hash, sig.SigType)
+ if err != nil {
+ return
+ }
+ io.Copy(wrappedHash, message)
+
+ err = sig.Sign(h, signer.PrivateKey, config)
+ if err != nil {
+ return
+ }
+
+ return sig.Serialize(w)
+}
+
+// FileHints contains metadata about encrypted files. This metadata is, itself,
+// encrypted.
+type FileHints struct {
+ // IsBinary can be set to hint that the contents are binary data.
+ IsBinary bool
+ // FileName hints at the name of the file that should be written. It's
+ // truncated to 255 bytes if longer. It may be empty to suggest that the
+ // file should not be written to disk. It may be equal to "_CONSOLE" to
+ // suggest the data should not be written to disk.
+ FileName string
+ // ModTime contains the modification time of the file, or the zero time if not applicable.
+ ModTime time.Time
+}
+
+// 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)
+}
+
+// intersectPreferences mutates and returns a prefix of a that contains only
+// the values in the intersection of a and b. The order of a is preserved.
+func intersectPreferences(a []uint8, b []uint8) (intersection []uint8) {
+ var j int
+ for _, v := range a {
+ for _, v2 := range b {
+ if v == v2 {
+ a[j] = v
+ j++
+ break
+ }
+ }
+ }
+
+ return a[:j]
+}
+
+func hashToHashId(h crypto.Hash) uint8 {
+ v, ok := s2k.HashToHashId(h)
+ if !ok {
+ panic("tried to convert unknown hash")
+ }
+ return v
+}
+
+// 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),
+ }
+ // In the event that a recipient doesn't specify any supported ciphers
+ // or hash functions, these are the ones that we assume that every
+ // implementation supports.
+ defaultCiphers := candidateCiphers[len(candidateCiphers)-1:]
+ defaultHashes := candidateHashes[len(candidateHashes)-1:]
+
+ 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 || len(candidateHashes) == 0 {
+ return nil, errors.InvalidArgumentError("cannot encrypt because recipient set shares no common algorithms")
+ }
+
+ cipher := packet.CipherFunction(candidateCiphers[0])
+ // If the cipher specified 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
+}
+
+// signatureWriter hashes the contents of a message while passing it along to
+// literalData. When closed, it closes literalData, writes a signature packet
+// to encryptedData and then also closes encryptedData.
+type signatureWriter struct {
+ encryptedData io.WriteCloser
+ literalData io.WriteCloser
+ hashType crypto.Hash
+ h hash.Hash
+ signer *packet.PrivateKey
+ config *packet.Config
+}
+
+func (s signatureWriter) Write(data []byte) (int, error) {
+ s.h.Write(data)
+ return s.literalData.Write(data)
+}
+
+func (s signatureWriter) Close() error {
+ sig := &packet.Signature{
+ SigType: packet.SigTypeBinary,
+ PubKeyAlgo: s.signer.PubKeyAlgo,
+ Hash: s.hashType,
+ CreationTime: s.config.Now(),
+ IssuerKeyId: &s.signer.KeyId,
+ }
+
+ if err := sig.Sign(s.h, s.signer, s.config); err != nil {
+ return err
+ }
+ if err := s.literalData.Close(); err != nil {
+ return err
+ }
+ if err := sig.Serialize(s.encryptedData); err != nil {
+ return err
+ }
+ return s.encryptedData.Close()
+}
+
+// noOpCloser is like an ioutil.NopCloser, but for an io.Writer.
+// TODO: we have two of these in OpenPGP packages alone. This probably needs
+// to be promoted somewhere more common.
+type noOpCloser struct {
+ w io.Writer
+}
+
+func (c noOpCloser) Write(data []byte) (n int, err error) {
+ return c.w.Write(data)
+}
+
+func (c noOpCloser) Close() error {
+ return nil
+}
projects / github / fretlink / terraform-provider-statuscake.git / blobdiff