diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/openpgp/packet/symmetrically_encrypted.go')
-rw-r--r-- | vendor/golang.org/x/crypto/openpgp/packet/symmetrically_encrypted.go | 290 |
1 files changed, 0 insertions, 290 deletions
diff --git a/vendor/golang.org/x/crypto/openpgp/packet/symmetrically_encrypted.go b/vendor/golang.org/x/crypto/openpgp/packet/symmetrically_encrypted.go deleted file mode 100644 index 6126030..0000000 --- a/vendor/golang.org/x/crypto/openpgp/packet/symmetrically_encrypted.go +++ /dev/null @@ -1,290 +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 ( - "crypto/cipher" - "crypto/sha1" - "crypto/subtle" - "golang.org/x/crypto/openpgp/errors" - "hash" - "io" - "strconv" -) - -// 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 { - MDC bool // true iff this is a type 18 packet and thus has an embedded MAC. - contents io.Reader - prefix []byte -} - -const symmetricallyEncryptedVersion = 1 - -func (se *SymmetricallyEncrypted) parse(r io.Reader) error { - if se.MDC { - // See RFC 4880, section 5.13. - var buf [1]byte - _, err := readFull(r, buf[:]) - if err != nil { - return err - } - if buf[0] != symmetricallyEncryptedVersion { - 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 can, with high probability, be detected -// immediately and this will result in a KeyIncorrect error being returned. -func (se *SymmetricallyEncrypted) Decrypt(c CipherFunction, key []byte) (io.ReadCloser, error) { - keySize := c.KeySize() - if keySize == 0 { - return nil, errors.UnsupportedError("unknown cipher: " + strconv.Itoa(int(c))) - } - if len(key) != keySize { - return nil, errors.InvalidArgumentError("SymmetricallyEncrypted: incorrect key length") - } - - if se.prefix == nil { - se.prefix = make([]byte, c.blockSize()+2) - _, err := readFull(se.contents, se.prefix) - if err != nil { - return nil, err - } - } else if len(se.prefix) != c.blockSize()+2 { - return nil, errors.InvalidArgumentError("can't try ciphers with different block lengths") - } - - ocfbResync := OCFBResync - if se.MDC { - // MDC packets use a different form of OCFB mode. - ocfbResync = OCFBNoResync - } - - s := NewOCFBDecrypter(c.new(key), se.prefix, ocfbResync) - if s == nil { - return nil, errors.ErrKeyIncorrect - } - - plaintext := cipher.StreamReader{S: s, R: se.contents} - - if se.MDC { - // MDC packets have an embedded hash that we need to check. - h := sha1.New() - h.Write(se.prefix) - return &seMDCReader{in: plaintext, h: h}, nil - } - - // Otherwise, we just need to wrap plaintext so that it's a valid ReadCloser. - return seReader{plaintext}, nil -} - -// seReader wraps an io.Reader with a no-op Close method. -type seReader struct { - in io.Reader -} - -func (ser seReader) Read(buf []byte) (int, error) { - return ser.in.Read(buf) -} - -func (ser seReader) Close() error { - return nil -} - -const mdcTrailerSize = 1 /* tag byte */ + 1 /* length byte */ + sha1.Size - -// An seMDCReader wraps an io.Reader, maintains a running hash and keeps hold -// of the most recent 22 bytes (mdcTrailerSize). Upon EOF, those bytes form an -// MDC packet containing a hash of the previous contents which is checked -// against the running hash. See RFC 4880, section 5.13. -type seMDCReader struct { - in io.Reader - h hash.Hash - trailer [mdcTrailerSize]byte - scratch [mdcTrailerSize]byte - trailerUsed int - error bool - eof bool -} - -func (ser *seMDCReader) Read(buf []byte) (n int, err error) { - if ser.error { - err = io.ErrUnexpectedEOF - return - } - if ser.eof { - err = io.EOF - return - } - - // If we haven't yet filled the trailer buffer then we must do that - // first. - for ser.trailerUsed < mdcTrailerSize { - n, err = ser.in.Read(ser.trailer[ser.trailerUsed:]) - ser.trailerUsed += n - if err == io.EOF { - if ser.trailerUsed != mdcTrailerSize { - n = 0 - err = io.ErrUnexpectedEOF - ser.error = true - return - } - ser.eof = true - n = 0 - return - } - - if err != nil { - n = 0 - return - } - } - - // If it's a short read then we read into a temporary buffer and shift - // the data into the caller's buffer. - if len(buf) <= mdcTrailerSize { - n, err = readFull(ser.in, ser.scratch[:len(buf)]) - copy(buf, ser.trailer[:n]) - ser.h.Write(buf[:n]) - copy(ser.trailer[:], ser.trailer[n:]) - copy(ser.trailer[mdcTrailerSize-n:], ser.scratch[:]) - if n < len(buf) { - ser.eof = true - err = io.EOF - } - return - } - - n, err = ser.in.Read(buf[mdcTrailerSize:]) - copy(buf, ser.trailer[:]) - ser.h.Write(buf[:n]) - copy(ser.trailer[:], buf[n:]) - - if err == io.EOF { - ser.eof = true - } - return -} - -// This is a new-format packet tag byte for a type 19 (MDC) packet. -const mdcPacketTagByte = byte(0x80) | 0x40 | 19 - -func (ser *seMDCReader) Close() error { - if ser.error { - return errors.SignatureError("error during reading") - } - - for !ser.eof { - // We haven't seen EOF so we need to read to the end - var buf [1024]byte - _, err := ser.Read(buf[:]) - if err == io.EOF { - break - } - if err != nil { - return errors.SignatureError("error during reading") - } - } - - if ser.trailer[0] != mdcPacketTagByte || ser.trailer[1] != sha1.Size { - return errors.SignatureError("MDC packet not found") - } - ser.h.Write(ser.trailer[:2]) - - final := ser.h.Sum(nil) - if subtle.ConstantTimeCompare(final, ser.trailer[2:]) != 1 { - return errors.SignatureError("hash mismatch") - } - return nil -} - -// An seMDCWriter writes through to an io.WriteCloser while maintains a running -// hash of the data written. On close, it emits an MDC packet containing the -// running hash. -type seMDCWriter struct { - w io.WriteCloser - h hash.Hash -} - -func (w *seMDCWriter) Write(buf []byte) (n int, err error) { - w.h.Write(buf) - return w.w.Write(buf) -} - -func (w *seMDCWriter) Close() (err error) { - var buf [mdcTrailerSize]byte - - buf[0] = mdcPacketTagByte - buf[1] = sha1.Size - w.h.Write(buf[:2]) - digest := w.h.Sum(nil) - copy(buf[2:], digest) - - _, err = w.w.Write(buf[:]) - if err != nil { - return - } - return w.w.Close() -} - -// noOpCloser is like an ioutil.NopCloser, but for an io.Writer. -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 -} - -// 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, key []byte, config *Config) (contents io.WriteCloser, err error) { - if c.KeySize() != len(key) { - return nil, errors.InvalidArgumentError("SymmetricallyEncrypted.Serialize: bad key length") - } - writeCloser := noOpCloser{w} - ciphertext, err := serializeStreamHeader(writeCloser, packetTypeSymmetricallyEncryptedMDC) - if err != nil { - return - } - - _, err = ciphertext.Write([]byte{symmetricallyEncryptedVersion}) - if err != nil { - return - } - - block := c.new(key) - blockSize := block.BlockSize() - iv := make([]byte, blockSize) - _, err = config.Random().Read(iv) - if err != nil { - return - } - s, prefix := NewOCFBEncrypter(block, iv, OCFBNoResync) - _, err = ciphertext.Write(prefix) - if err != nil { - return - } - plaintext := cipher.StreamWriter{S: s, W: ciphertext} - - h := sha1.New() - h.Write(iv) - h.Write(iv[blockSize-2:]) - contents = &seMDCWriter{w: plaintext, h: h} - return -} |