diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/openpgp/read.go')
| -rw-r--r-- | vendor/golang.org/x/crypto/openpgp/read.go | 442 |
1 files changed, 0 insertions, 442 deletions
diff --git a/vendor/golang.org/x/crypto/openpgp/read.go b/vendor/golang.org/x/crypto/openpgp/read.go deleted file mode 100644 index 6ec664f4..00000000 --- a/vendor/golang.org/x/crypto/openpgp/read.go +++ /dev/null @@ -1,442 +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 openpgp implements high level operations on OpenPGP messages. -package openpgp // import "golang.org/x/crypto/openpgp" - -import ( - "crypto" - _ "crypto/sha256" - "hash" - "io" - "strconv" - - "golang.org/x/crypto/openpgp/armor" - "golang.org/x/crypto/openpgp/errors" - "golang.org/x/crypto/openpgp/packet" -) - -// SignatureType is the armor type for a PGP signature. -var SignatureType = "PGP SIGNATURE" - -// readArmored reads an armored block with the given type. -func readArmored(r io.Reader, expectedType string) (body io.Reader, err error) { - block, err := armor.Decode(r) - if err != nil { - return - } - - if block.Type != expectedType { - return nil, errors.InvalidArgumentError("expected '" + expectedType + "', got: " + block.Type) - } - - return block.Body, nil -} - -// MessageDetails contains the result of parsing an OpenPGP encrypted and/or -// signed message. -type MessageDetails struct { - IsEncrypted bool // true if the message was encrypted. - EncryptedToKeyIds []uint64 // the list of recipient key ids. - IsSymmetricallyEncrypted bool // true if a passphrase could have decrypted the message. - DecryptedWith Key // the private key used to decrypt the message, if any. - IsSigned bool // true if the message is signed. - SignedByKeyId uint64 // the key id of the signer, if any. - SignedBy *Key // the key of the signer, if available. - LiteralData *packet.LiteralData // the metadata of the contents - UnverifiedBody io.Reader // the contents of the message. - - // If IsSigned is true and SignedBy is non-zero then the signature will - // be verified as UnverifiedBody is read. The signature cannot be - // checked until the whole of UnverifiedBody is read so UnverifiedBody - // must be consumed until EOF before the data can be trusted. Even if a - // message isn't signed (or the signer is unknown) the data may contain - // an authentication code that is only checked once UnverifiedBody has - // been consumed. Once EOF has been seen, the following fields are - // valid. (An authentication code failure is reported as a - // SignatureError error when reading from UnverifiedBody.) - SignatureError error // nil if the signature is good. - Signature *packet.Signature // the signature packet itself, if v4 (default) - SignatureV3 *packet.SignatureV3 // the signature packet if it is a v2 or v3 signature - - decrypted io.ReadCloser -} - -// A PromptFunction is used as a callback by functions that may need to decrypt -// a private key, or prompt for a passphrase. It is called with a list of -// acceptable, encrypted private keys and a boolean that indicates whether a -// passphrase is usable. It should either decrypt a private key or return a -// passphrase to try. If the decrypted private key or given passphrase isn't -// correct, the function will be called again, forever. Any error returned will -// be passed up. -type PromptFunction func(keys []Key, symmetric bool) ([]byte, error) - -// A keyEnvelopePair is used to store a private key with the envelope that -// contains a symmetric key, encrypted with that key. -type keyEnvelopePair struct { - key Key - encryptedKey *packet.EncryptedKey -} - -// ReadMessage parses an OpenPGP message that may be signed and/or encrypted. -// The given KeyRing should contain both public keys (for signature -// verification) and, possibly encrypted, private keys for decrypting. -// If config is nil, sensible defaults will be used. -func ReadMessage(r io.Reader, keyring KeyRing, prompt PromptFunction, config *packet.Config) (md *MessageDetails, err error) { - var p packet.Packet - - var symKeys []*packet.SymmetricKeyEncrypted - var pubKeys []keyEnvelopePair - var se *packet.SymmetricallyEncrypted - - packets := packet.NewReader(r) - md = new(MessageDetails) - md.IsEncrypted = true - - // The message, if encrypted, starts with a number of packets - // containing an encrypted decryption key. The decryption key is either - // encrypted to a public key, or with a passphrase. This loop - // collects these packets. -ParsePackets: - for { - p, err = packets.Next() - if err != nil { - return nil, err - } - switch p := p.(type) { - case *packet.SymmetricKeyEncrypted: - // This packet contains the decryption key encrypted with a passphrase. - md.IsSymmetricallyEncrypted = true - symKeys = append(symKeys, p) - case *packet.EncryptedKey: - // This packet contains the decryption key encrypted to a public key. - md.EncryptedToKeyIds = append(md.EncryptedToKeyIds, p.KeyId) - switch p.Algo { - case packet.PubKeyAlgoRSA, packet.PubKeyAlgoRSAEncryptOnly, packet.PubKeyAlgoElGamal: - break - default: - continue - } - var keys []Key - if p.KeyId == 0 { - keys = keyring.DecryptionKeys() - } else { - keys = keyring.KeysById(p.KeyId) - } - for _, k := range keys { - pubKeys = append(pubKeys, keyEnvelopePair{k, p}) - } - case *packet.SymmetricallyEncrypted: - se = p - break ParsePackets - case *packet.Compressed, *packet.LiteralData, *packet.OnePassSignature: - // This message isn't encrypted. - if len(symKeys) != 0 || len(pubKeys) != 0 { - return nil, errors.StructuralError("key material not followed by encrypted message") - } - packets.Unread(p) - return readSignedMessage(packets, nil, keyring) - } - } - - var candidates []Key - var decrypted io.ReadCloser - - // Now that we have the list of encrypted keys we need to decrypt at - // least one of them or, if we cannot, we need to call the prompt - // function so that it can decrypt a key or give us a passphrase. -FindKey: - for { - // See if any of the keys already have a private key available - candidates = candidates[:0] - candidateFingerprints := make(map[string]bool) - - for _, pk := range pubKeys { - if pk.key.PrivateKey == nil { - continue - } - if !pk.key.PrivateKey.Encrypted { - if len(pk.encryptedKey.Key) == 0 { - pk.encryptedKey.Decrypt(pk.key.PrivateKey, config) - } - if len(pk.encryptedKey.Key) == 0 { - continue - } - decrypted, err = se.Decrypt(pk.encryptedKey.CipherFunc, pk.encryptedKey.Key) - if err != nil && err != errors.ErrKeyIncorrect { - return nil, err - } - if decrypted != nil { - md.DecryptedWith = pk.key - break FindKey - } - } else { - fpr := string(pk.key.PublicKey.Fingerprint[:]) - if v := candidateFingerprints[fpr]; v { - continue - } - candidates = append(candidates, pk.key) - candidateFingerprints[fpr] = true - } - } - - if len(candidates) == 0 && len(symKeys) == 0 { - return nil, errors.ErrKeyIncorrect - } - - if prompt == nil { - return nil, errors.ErrKeyIncorrect - } - - passphrase, err := prompt(candidates, len(symKeys) != 0) - if err != nil { - return nil, err - } - - // Try the symmetric passphrase first - if len(symKeys) != 0 && passphrase != nil { - for _, s := range symKeys { - key, cipherFunc, err := s.Decrypt(passphrase) - if err == nil { - decrypted, err = se.Decrypt(cipherFunc, key) - if err != nil && err != errors.ErrKeyIncorrect { - return nil, err - } - if decrypted != nil { - break FindKey - } - } - - } - } - } - - md.decrypted = decrypted - if err := packets.Push(decrypted); err != nil { - return nil, err - } - return readSignedMessage(packets, md, keyring) -} - -// readSignedMessage reads a possibly signed message if mdin is non-zero then -// that structure is updated and returned. Otherwise a fresh MessageDetails is -// used. -func readSignedMessage(packets *packet.Reader, mdin *MessageDetails, keyring KeyRing) (md *MessageDetails, err error) { - if mdin == nil { - mdin = new(MessageDetails) - } - md = mdin - - var p packet.Packet - var h hash.Hash - var wrappedHash hash.Hash -FindLiteralData: - for { - p, err = packets.Next() - if err != nil { - return nil, err - } - switch p := p.(type) { - case *packet.Compressed: - if err := packets.Push(p.Body); err != nil { - return nil, err - } - case *packet.OnePassSignature: - if !p.IsLast { - return nil, errors.UnsupportedError("nested signatures") - } - - h, wrappedHash, err = hashForSignature(p.Hash, p.SigType) - if err != nil { - md = nil - return - } - - md.IsSigned = true - md.SignedByKeyId = p.KeyId - keys := keyring.KeysByIdUsage(p.KeyId, packet.KeyFlagSign) - if len(keys) > 0 { - md.SignedBy = &keys[0] - } - case *packet.LiteralData: - md.LiteralData = p - break FindLiteralData - } - } - - if md.SignedBy != nil { - md.UnverifiedBody = &signatureCheckReader{packets, h, wrappedHash, md} - } else if md.decrypted != nil { - md.UnverifiedBody = checkReader{md} - } else { - md.UnverifiedBody = md.LiteralData.Body - } - - return md, nil -} - -// hashForSignature returns a pair of hashes that can be used to verify a -// signature. The signature may specify that the contents of the signed message -// should be preprocessed (i.e. to normalize line endings). Thus this function -// returns two hashes. The second should be used to hash the message itself and -// performs any needed preprocessing. -func hashForSignature(hashId crypto.Hash, sigType packet.SignatureType) (hash.Hash, hash.Hash, error) { - if !hashId.Available() { - return nil, nil, errors.UnsupportedError("hash not available: " + strconv.Itoa(int(hashId))) - } - h := hashId.New() - - switch sigType { - case packet.SigTypeBinary: - return h, h, nil - case packet.SigTypeText: - return h, NewCanonicalTextHash(h), nil - } - - return nil, nil, errors.UnsupportedError("unsupported signature type: " + strconv.Itoa(int(sigType))) -} - -// checkReader wraps an io.Reader from a LiteralData packet. When it sees EOF -// it closes the ReadCloser from any SymmetricallyEncrypted packet to trigger -// MDC checks. -type checkReader struct { - md *MessageDetails -} - -func (cr checkReader) Read(buf []byte) (n int, err error) { - n, err = cr.md.LiteralData.Body.Read(buf) - if err == io.EOF { - mdcErr := cr.md.decrypted.Close() - if mdcErr != nil { - err = mdcErr - } - } - return -} - -// signatureCheckReader wraps an io.Reader from a LiteralData packet and hashes -// the data as it is read. When it sees an EOF from the underlying io.Reader -// it parses and checks a trailing Signature packet and triggers any MDC checks. -type signatureCheckReader struct { - packets *packet.Reader - h, wrappedHash hash.Hash - md *MessageDetails -} - -func (scr *signatureCheckReader) Read(buf []byte) (n int, err error) { - n, err = scr.md.LiteralData.Body.Read(buf) - scr.wrappedHash.Write(buf[:n]) - if err == io.EOF { - var p packet.Packet - p, scr.md.SignatureError = scr.packets.Next() - if scr.md.SignatureError != nil { - return - } - - var ok bool - if scr.md.Signature, ok = p.(*packet.Signature); ok { - scr.md.SignatureError = scr.md.SignedBy.PublicKey.VerifySignature(scr.h, scr.md.Signature) - } else if scr.md.SignatureV3, ok = p.(*packet.SignatureV3); ok { - scr.md.SignatureError = scr.md.SignedBy.PublicKey.VerifySignatureV3(scr.h, scr.md.SignatureV3) - } else { - scr.md.SignatureError = errors.StructuralError("LiteralData not followed by Signature") - return - } - - // The SymmetricallyEncrypted packet, if any, might have an - // unsigned hash of its own. In order to check this we need to - // close that Reader. - if scr.md.decrypted != nil { - mdcErr := scr.md.decrypted.Close() - if mdcErr != nil { - err = mdcErr - } - } - } - return -} - -// CheckDetachedSignature takes a signed file and a detached signature and -// returns the signer if the signature is valid. If the signer isn't known, -// ErrUnknownIssuer is returned. -func CheckDetachedSignature(keyring KeyRing, signed, signature io.Reader) (signer *Entity, err error) { - var issuerKeyId uint64 - var hashFunc crypto.Hash - var sigType packet.SignatureType - var keys []Key - var p packet.Packet - - packets := packet.NewReader(signature) - for { - p, err = packets.Next() - if err == io.EOF { - return nil, errors.ErrUnknownIssuer - } - if err != nil { - return nil, err - } - - switch sig := p.(type) { - case *packet.Signature: - if sig.IssuerKeyId == nil { - return nil, errors.StructuralError("signature doesn't have an issuer") - } - issuerKeyId = *sig.IssuerKeyId - hashFunc = sig.Hash - sigType = sig.SigType - case *packet.SignatureV3: - issuerKeyId = sig.IssuerKeyId - hashFunc = sig.Hash - sigType = sig.SigType - default: - return nil, errors.StructuralError("non signature packet found") - } - - keys = keyring.KeysByIdUsage(issuerKeyId, packet.KeyFlagSign) - if len(keys) > 0 { - break - } - } - - if len(keys) == 0 { - panic("unreachable") - } - - h, wrappedHash, err := hashForSignature(hashFunc, sigType) - if err != nil { - return nil, err - } - - if _, err := io.Copy(wrappedHash, signed); err != nil && err != io.EOF { - return nil, err - } - - for _, key := range keys { - switch sig := p.(type) { - case *packet.Signature: - err = key.PublicKey.VerifySignature(h, sig) - case *packet.SignatureV3: - err = key.PublicKey.VerifySignatureV3(h, sig) - default: - panic("unreachable") - } - - if err == nil { - return key.Entity, nil - } - } - - return nil, err -} - -// CheckArmoredDetachedSignature performs the same actions as -// CheckDetachedSignature but expects the signature to be armored. -func CheckArmoredDetachedSignature(keyring KeyRing, signed, signature io.Reader) (signer *Entity, err error) { - body, err := readArmored(signature, SignatureType) - if err != nil { - return - } - - return CheckDetachedSignature(keyring, signed, body) -} |