balki/pgweb
1
0
Fork 0
Code Pull Requests Activity

Switch to dep for dependency management

Browse Source
This commit is contained in:
Dan Sosedoff
2018-08-31 21:49:24 -05:00
parent 847f47c5d3
commit ad81f666a5
537 changed files with 167100 additions and 34410 deletions
Download Patch File Download Diff File Expand all files Collapse all files

319
vendor/golang.org/x/crypto/ssh/cipher.go generated vendored
View File

@@ -16,6 +16,10 @@ import (
"hash"
"io"
"io/ioutil"
"math/bits"
"golang.org/x/crypto/internal/chacha20"
"golang.org/x/crypto/poly1305"
)
const (
@@ -53,78 +57,78 @@ func newRC4(key, iv []byte) (cipher.Stream, error) {
return rc4.NewCipher(key)
}
type streamCipherMode struct {
keySize int
ivSize int
skip int
createFunc func(key, iv []byte) (cipher.Stream, error)
type cipherMode struct {
keySize int
ivSize int
create func(key, iv []byte, macKey []byte, algs directionAlgorithms) (packetCipher, error)
}
func (c *streamCipherMode) createStream(key, iv []byte) (cipher.Stream, error) {
if len(key) < c.keySize {
panic("ssh: key length too small for cipher")
}
if len(iv) < c.ivSize {
panic("ssh: iv too small for cipher")
}
stream, err := c.createFunc(key[:c.keySize], iv[:c.ivSize])
if err != nil {
return nil, err
}
var streamDump []byte
if c.skip > 0 {
streamDump = make([]byte, 512)
}
for remainingToDump := c.skip; remainingToDump > 0; {
dumpThisTime := remainingToDump
if dumpThisTime > len(streamDump) {
dumpThisTime = len(streamDump)
func streamCipherMode(skip int, createFunc func(key, iv []byte) (cipher.Stream, error)) func(key, iv []byte, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
return func(key, iv, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
stream, err := createFunc(key, iv)
if err != nil {
return nil, err
}
stream.XORKeyStream(streamDump[:dumpThisTime], streamDump[:dumpThisTime])
remainingToDump -= dumpThisTime
}
return stream, nil
var streamDump []byte
if skip > 0 {
streamDump = make([]byte, 512)
}
for remainingToDump := skip; remainingToDump > 0; {
dumpThisTime := remainingToDump
if dumpThisTime > len(streamDump) {
dumpThisTime = len(streamDump)
}
stream.XORKeyStream(streamDump[:dumpThisTime], streamDump[:dumpThisTime])
remainingToDump -= dumpThisTime
}
mac := macModes[algs.MAC].new(macKey)
return &streamPacketCipher{
mac: mac,
etm: macModes[algs.MAC].etm,
macResult: make([]byte, mac.Size()),
cipher: stream,
}, nil
}
}
// cipherModes documents properties of supported ciphers. Ciphers not included
// are not supported and will not be negotiated, even if explicitly requested in
// ClientConfig.Crypto.Ciphers.
var cipherModes = map[string]*streamCipherMode{
var cipherModes = map[string]*cipherMode{
// Ciphers from RFC4344, which introduced many CTR-based ciphers. Algorithms
// are defined in the order specified in the RFC.
"aes128-ctr": {16, aes.BlockSize, 0, newAESCTR},
"aes192-ctr": {24, aes.BlockSize, 0, newAESCTR},
"aes256-ctr": {32, aes.BlockSize, 0, newAESCTR},
"aes128-ctr": {16, aes.BlockSize, streamCipherMode(0, newAESCTR)},
"aes192-ctr": {24, aes.BlockSize, streamCipherMode(0, newAESCTR)},
"aes256-ctr": {32, aes.BlockSize, streamCipherMode(0, newAESCTR)},
// Ciphers from RFC4345, which introduces security-improved arcfour ciphers.
// They are defined in the order specified in the RFC.
"arcfour128": {16, 0, 1536, newRC4},
"arcfour256": {32, 0, 1536, newRC4},
"arcfour128": {16, 0, streamCipherMode(1536, newRC4)},
"arcfour256": {32, 0, streamCipherMode(1536, newRC4)},
// Cipher defined in RFC 4253, which describes SSH Transport Layer Protocol.
// Note that this cipher is not safe, as stated in RFC 4253: "Arcfour (and
// RC4) has problems with weak keys, and should be used with caution."
// RFC4345 introduces improved versions of Arcfour.
"arcfour": {16, 0, 0, newRC4},
"arcfour": {16, 0, streamCipherMode(0, newRC4)},
// AES-GCM is not a stream cipher, so it is constructed with a
// special case. If we add any more non-stream ciphers, we
// should invest a cleaner way to do this.
gcmCipherID: {16, 12, 0, nil},
// AEAD ciphers
gcmCipherID: {16, 12, newGCMCipher},
chacha20Poly1305ID: {64, 0, newChaCha20Cipher},
// CBC mode is insecure and so is not included in the default config.
// (See http://www.isg.rhul.ac.uk/~kp/SandPfinal.pdf). If absolutely
// needed, it's possible to specify a custom Config to enable it.
// You should expect that an active attacker can recover plaintext if
// you do.
aes128cbcID: {16, aes.BlockSize, 0, nil},
aes128cbcID: {16, aes.BlockSize, newAESCBCCipher},
// 3des-cbc is insecure and is disabled by default.
tripledescbcID: {24, des.BlockSize, 0, nil},
// 3des-cbc is insecure and is not included in the default
// config.
tripledescbcID: {24, des.BlockSize, newTripleDESCBCCipher},
}
// prefixLen is the length of the packet prefix that contains the packet length
@@ -135,6 +139,7 @@ const prefixLen = 5
type streamPacketCipher struct {
mac hash.Hash
cipher cipher.Stream
etm bool
// The following members are to avoid per-packet allocations.
prefix [prefixLen]byte
@@ -150,7 +155,14 @@ func (s *streamPacketCipher) readPacket(seqNum uint32, r io.Reader) ([]byte, err
return nil, err
}
s.cipher.XORKeyStream(s.prefix[:], s.prefix[:])
var encryptedPaddingLength [1]byte
if s.mac != nil && s.etm {
copy(encryptedPaddingLength[:], s.prefix[4:5])
s.cipher.XORKeyStream(s.prefix[4:5], s.prefix[4:5])
} else {
s.cipher.XORKeyStream(s.prefix[:], s.prefix[:])
}
length := binary.BigEndian.Uint32(s.prefix[0:4])
paddingLength := uint32(s.prefix[4])
@@ -159,7 +171,12 @@ func (s *streamPacketCipher) readPacket(seqNum uint32, r io.Reader) ([]byte, err
s.mac.Reset()
binary.BigEndian.PutUint32(s.seqNumBytes[:], seqNum)
s.mac.Write(s.seqNumBytes[:])
s.mac.Write(s.prefix[:])
if s.etm {
s.mac.Write(s.prefix[:4])
s.mac.Write(encryptedPaddingLength[:])
} else {
s.mac.Write(s.prefix[:])
}
macSize = uint32(s.mac.Size())
}
@@ -184,10 +201,17 @@ func (s *streamPacketCipher) readPacket(seqNum uint32, r io.Reader) ([]byte, err
}
mac := s.packetData[length-1:]
data := s.packetData[:length-1]
if s.mac != nil && s.etm {
s.mac.Write(data)
}
s.cipher.XORKeyStream(data, data)
if s.mac != nil {
s.mac.Write(data)
if !s.etm {
s.mac.Write(data)
}
s.macResult = s.mac.Sum(s.macResult[:0])
if subtle.ConstantTimeCompare(s.macResult, mac) != 1 {
return nil, errors.New("ssh: MAC failure")
@@ -203,7 +227,13 @@ func (s *streamPacketCipher) writePacket(seqNum uint32, w io.Writer, rand io.Rea
return errors.New("ssh: packet too large")
}
paddingLength := packetSizeMultiple - (prefixLen+len(packet))%packetSizeMultiple
aadlen := 0
if s.mac != nil && s.etm {
// packet length is not encrypted for EtM modes
aadlen = 4
}
paddingLength := packetSizeMultiple - (prefixLen+len(packet)-aadlen)%packetSizeMultiple
if paddingLength < 4 {
paddingLength += packetSizeMultiple
}
@@ -220,15 +250,37 @@ func (s *streamPacketCipher) writePacket(seqNum uint32, w io.Writer, rand io.Rea
s.mac.Reset()
binary.BigEndian.PutUint32(s.seqNumBytes[:], seqNum)
s.mac.Write(s.seqNumBytes[:])
if s.etm {
// For EtM algorithms, the packet length must stay unencrypted,
// but the following data (padding length) must be encrypted
s.cipher.XORKeyStream(s.prefix[4:5], s.prefix[4:5])
}
s.mac.Write(s.prefix[:])
if !s.etm {
// For non-EtM algorithms, the algorithm is applied on unencrypted data
s.mac.Write(packet)
s.mac.Write(padding)
}
}
if !(s.mac != nil && s.etm) {
// For EtM algorithms, the padding length has already been encrypted
// and the packet length must remain unencrypted
s.cipher.XORKeyStream(s.prefix[:], s.prefix[:])
}
s.cipher.XORKeyStream(packet, packet)
s.cipher.XORKeyStream(padding, padding)
if s.mac != nil && s.etm {
// For EtM algorithms, packet and padding must be encrypted
s.mac.Write(packet)
s.mac.Write(padding)
}
s.cipher.XORKeyStream(s.prefix[:], s.prefix[:])
s.cipher.XORKeyStream(packet, packet)
s.cipher.XORKeyStream(padding, padding)
if _, err := w.Write(s.prefix[:]); err != nil {
return err
}
@@ -256,7 +308,7 @@ type gcmCipher struct {
buf []byte
}
func newGCMCipher(iv, key, macKey []byte) (packetCipher, error) {
func newGCMCipher(key, iv, unusedMacKey []byte, unusedAlgs directionAlgorithms) (packetCipher, error) {
c, err := aes.NewCipher(key)
if err != nil {
return nil, err
@@ -324,7 +376,7 @@ func (c *gcmCipher) readPacket(seqNum uint32, r io.Reader) ([]byte, error) {
}
length := binary.BigEndian.Uint32(c.prefix[:])
if length > maxPacket {
return nil, errors.New("ssh: max packet length exceeded.")
return nil, errors.New("ssh: max packet length exceeded")
}
if cap(c.buf) < int(length+gcmTagSize) {
@@ -344,7 +396,9 @@ func (c *gcmCipher) readPacket(seqNum uint32, r io.Reader) ([]byte, error) {
c.incIV()
padding := plain[0]
if padding < 4 || padding >= 20 {
if padding < 4 {
// padding is a byte, so it automatically satisfies
// the maximum size, which is 255.
return nil, fmt.Errorf("ssh: illegal padding %d", padding)
}
@@ -372,7 +426,7 @@ type cbcCipher struct {
oracleCamouflage uint32
}
func newCBCCipher(c cipher.Block, iv, key, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
func newCBCCipher(c cipher.Block, key, iv, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
cbc := &cbcCipher{
mac: macModes[algs.MAC].new(macKey),
decrypter: cipher.NewCBCDecrypter(c, iv),
@@ -386,13 +440,13 @@ func newCBCCipher(c cipher.Block, iv, key, macKey []byte, algs directionAlgorith
return cbc, nil
}
func newAESCBCCipher(iv, key, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
func newAESCBCCipher(key, iv, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
c, err := aes.NewCipher(key)
if err != nil {
return nil, err
}
cbc, err := newCBCCipher(c, iv, key, macKey, algs)
cbc, err := newCBCCipher(c, key, iv, macKey, algs)
if err != nil {
return nil, err
}
@@ -400,13 +454,13 @@ func newAESCBCCipher(iv, key, macKey []byte, algs directionAlgorithms) (packetCi
return cbc, nil
}
func newTripleDESCBCCipher(iv, key, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
func newTripleDESCBCCipher(key, iv, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
c, err := des.NewTripleDESCipher(key)
if err != nil {
return nil, err
}
cbc, err := newCBCCipher(c, iv, key, macKey, algs)
cbc, err := newCBCCipher(c, key, iv, macKey, algs)
if err != nil {
return nil, err
}
@@ -498,11 +552,11 @@ func (c *cbcCipher) readPacketLeaky(seqNum uint32, r io.Reader) ([]byte, error)
c.packetData = c.packetData[:entirePacketSize]
}
if n, err := io.ReadFull(r, c.packetData[firstBlockLength:]); err != nil {
n, err := io.ReadFull(r, c.packetData[firstBlockLength:])
if err != nil {
return nil, err
} else {
c.oracleCamouflage -= uint32(n)
}
c.oracleCamouflage -= uint32(n)
remainingCrypted := c.packetData[firstBlockLength:macStart]
c.decrypter.CryptBlocks(remainingCrypted, remainingCrypted)
@@ -577,3 +631,140 @@ func (c *cbcCipher) writePacket(seqNum uint32, w io.Writer, rand io.Reader, pack
return nil
}
const chacha20Poly1305ID = "chacha20-poly1305@openssh.com"
// chacha20Poly1305Cipher implements the chacha20-poly1305@openssh.com
// AEAD, which is described here:
//
// https://tools.ietf.org/html/draft-josefsson-ssh-chacha20-poly1305-openssh-00
//
// the methods here also implement padding, which RFC4253 Section 6
// also requires of stream ciphers.
type chacha20Poly1305Cipher struct {
lengthKey [8]uint32
contentKey [8]uint32
buf []byte
}
func newChaCha20Cipher(key, unusedIV, unusedMACKey []byte, unusedAlgs directionAlgorithms) (packetCipher, error) {
if len(key) != 64 {
panic(len(key))
}
c := &chacha20Poly1305Cipher{
buf: make([]byte, 256),
}
for i := range c.contentKey {
c.contentKey[i] = binary.LittleEndian.Uint32(key[i*4 : (i+1)*4])
}
for i := range c.lengthKey {
c.lengthKey[i] = binary.LittleEndian.Uint32(key[(i+8)*4 : (i+9)*4])
}
return c, nil
}
func (c *chacha20Poly1305Cipher) readPacket(seqNum uint32, r io.Reader) ([]byte, error) {
nonce := [3]uint32{0, 0, bits.ReverseBytes32(seqNum)}
s := chacha20.New(c.contentKey, nonce)
var polyKey [32]byte
s.XORKeyStream(polyKey[:], polyKey[:])
s.Advance() // skip next 32 bytes
encryptedLength := c.buf[:4]
if _, err := io.ReadFull(r, encryptedLength); err != nil {
return nil, err
}
var lenBytes [4]byte
chacha20.New(c.lengthKey, nonce).XORKeyStream(lenBytes[:], encryptedLength)
length := binary.BigEndian.Uint32(lenBytes[:])
if length > maxPacket {
return nil, errors.New("ssh: invalid packet length, packet too large")
}
contentEnd := 4 + length
packetEnd := contentEnd + poly1305.TagSize
if uint32(cap(c.buf)) < packetEnd {
c.buf = make([]byte, packetEnd)
copy(c.buf[:], encryptedLength)
} else {
c.buf = c.buf[:packetEnd]
}
if _, err := io.ReadFull(r, c.buf[4:packetEnd]); err != nil {
return nil, err
}
var mac [poly1305.TagSize]byte
copy(mac[:], c.buf[contentEnd:packetEnd])
if !poly1305.Verify(&mac, c.buf[:contentEnd], &polyKey) {
return nil, errors.New("ssh: MAC failure")
}
plain := c.buf[4:contentEnd]
s.XORKeyStream(plain, plain)
padding := plain[0]
if padding < 4 {
// padding is a byte, so it automatically satisfies
// the maximum size, which is 255.
return nil, fmt.Errorf("ssh: illegal padding %d", padding)
}
if int(padding)+1 >= len(plain) {
return nil, fmt.Errorf("ssh: padding %d too large", padding)
}
plain = plain[1 : len(plain)-int(padding)]
return plain, nil
}
func (c *chacha20Poly1305Cipher) writePacket(seqNum uint32, w io.Writer, rand io.Reader, payload []byte) error {
nonce := [3]uint32{0, 0, bits.ReverseBytes32(seqNum)}
s := chacha20.New(c.contentKey, nonce)
var polyKey [32]byte
s.XORKeyStream(polyKey[:], polyKey[:])
s.Advance() // skip next 32 bytes
// There is no blocksize, so fall back to multiple of 8 byte
// padding, as described in RFC 4253, Sec 6.
const packetSizeMultiple = 8
padding := packetSizeMultiple - (1+len(payload))%packetSizeMultiple
if padding < 4 {
padding += packetSizeMultiple
}
// size (4 bytes), padding (1), payload, padding, tag.
totalLength := 4 + 1 + len(payload) + padding + poly1305.TagSize
if cap(c.buf) < totalLength {
c.buf = make([]byte, totalLength)
} else {
c.buf = c.buf[:totalLength]
}
binary.BigEndian.PutUint32(c.buf, uint32(1+len(payload)+padding))
chacha20.New(c.lengthKey, nonce).XORKeyStream(c.buf, c.buf[:4])
c.buf[4] = byte(padding)
copy(c.buf[5:], payload)
packetEnd := 5 + len(payload) + padding
if _, err := io.ReadFull(rand, c.buf[5+len(payload):packetEnd]); err != nil {
return err
}
s.XORKeyStream(c.buf[4:], c.buf[4:packetEnd])
var mac [poly1305.TagSize]byte
poly1305.Sum(&mac, c.buf[:packetEnd], &polyKey)
copy(c.buf[packetEnd:], mac[:])
if _, err := w.Write(c.buf); err != nil {
return err
}
return nil
}