Switch to dep for dependency management

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

View File

@@ -6,10 +6,16 @@ package ssh
import (
"bufio"
"bytes"
"errors"
"io"
"log"
)
// debugTransport if set, will print packet types as they go over the
// wire. No message decoding is done, to minimize the impact on timing.
const debugTransport = false
const (
gcmCipherID = "aes128-gcm@openssh.com"
aes128cbcID = "aes128-cbc"
@@ -22,7 +28,9 @@ type packetConn interface {
// Encrypt and send a packet of data to the remote peer.
writePacket(packet []byte) error
// Read a packet from the connection
// Read a packet from the connection. The read is blocking,
// i.e. if error is nil, then the returned byte slice is
// always non-empty.
readPacket() ([]byte, error)
// Close closes the write-side of the connection.
@@ -38,7 +46,7 @@ type transport struct {
bufReader *bufio.Reader
bufWriter *bufio.Writer
rand io.Reader
isClient bool
io.Closer
}
@@ -69,24 +77,53 @@ type connectionState struct {
// both directions are triggered by reading and writing a msgNewKey packet
// respectively.
func (t *transport) prepareKeyChange(algs *algorithms, kexResult *kexResult) error {
if ciph, err := newPacketCipher(t.reader.dir, algs.r, kexResult); err != nil {
ciph, err := newPacketCipher(t.reader.dir, algs.r, kexResult)
if err != nil {
return err
} else {
t.reader.pendingKeyChange <- ciph
}
t.reader.pendingKeyChange <- ciph
if ciph, err := newPacketCipher(t.writer.dir, algs.w, kexResult); err != nil {
ciph, err = newPacketCipher(t.writer.dir, algs.w, kexResult)
if err != nil {
return err
} else {
t.writer.pendingKeyChange <- ciph
}
t.writer.pendingKeyChange <- ciph
return nil
}
func (t *transport) printPacket(p []byte, write bool) {
if len(p) == 0 {
return
}
who := "server"
if t.isClient {
who = "client"
}
what := "read"
if write {
what = "write"
}
log.Println(what, who, p[0])
}
// Read and decrypt next packet.
func (t *transport) readPacket() ([]byte, error) {
return t.reader.readPacket(t.bufReader)
func (t *transport) readPacket() (p []byte, err error) {
for {
p, err = t.reader.readPacket(t.bufReader)
if err != nil {
break
}
if len(p) == 0 || (p[0] != msgIgnore && p[0] != msgDebug) {
break
}
}
if debugTransport {
t.printPacket(p, false)
}
return p, err
}
func (s *connectionState) readPacket(r *bufio.Reader) ([]byte, error) {
@@ -103,7 +140,7 @@ func (s *connectionState) readPacket(r *bufio.Reader) ([]byte, error) {
case cipher := <-s.pendingKeyChange:
s.packetCipher = cipher
default:
return nil, errors.New("ssh: got bogus newkeys message.")
return nil, errors.New("ssh: got bogus newkeys message")
}
case msgDisconnect:
@@ -129,6 +166,9 @@ func (s *connectionState) readPacket(r *bufio.Reader) ([]byte, error) {
}
func (t *transport) writePacket(packet []byte) error {
if debugTransport {
t.printPacket(packet, true)
}
return t.writer.writePacket(t.bufWriter, t.rand, packet)
}
@@ -169,6 +209,8 @@ func newTransport(rwc io.ReadWriteCloser, rand io.Reader, isClient bool) *transp
},
Closer: rwc,
}
t.isClient = isClient
if isClient {
t.reader.dir = serverKeys
t.writer.dir = clientKeys
@@ -191,51 +233,22 @@ var (
clientKeys = direction{[]byte{'A'}, []byte{'C'}, []byte{'E'}}
)
// generateKeys generates key material for IV, MAC and encryption.
func generateKeys(d direction, algs directionAlgorithms, kex *kexResult) (iv, key, macKey []byte) {
cipherMode := cipherModes[algs.Cipher]
macMode := macModes[algs.MAC]
iv = make([]byte, cipherMode.ivSize)
key = make([]byte, cipherMode.keySize)
macKey = make([]byte, macMode.keySize)
generateKeyMaterial(iv, d.ivTag, kex)
generateKeyMaterial(key, d.keyTag, kex)
generateKeyMaterial(macKey, d.macKeyTag, kex)
return
}
// setupKeys sets the cipher and MAC keys from kex.K, kex.H and sessionId, as
// described in RFC 4253, section 6.4. direction should either be serverKeys
// (to setup server->client keys) or clientKeys (for client->server keys).
func newPacketCipher(d direction, algs directionAlgorithms, kex *kexResult) (packetCipher, error) {
iv, key, macKey := generateKeys(d, algs, kex)
cipherMode := cipherModes[algs.Cipher]
macMode := macModes[algs.MAC]
if algs.Cipher == gcmCipherID {
return newGCMCipher(iv, key, macKey)
}
iv := make([]byte, cipherMode.ivSize)
key := make([]byte, cipherMode.keySize)
macKey := make([]byte, macMode.keySize)
if algs.Cipher == aes128cbcID {
return newAESCBCCipher(iv, key, macKey, algs)
}
generateKeyMaterial(iv, d.ivTag, kex)
generateKeyMaterial(key, d.keyTag, kex)
generateKeyMaterial(macKey, d.macKeyTag, kex)
if algs.Cipher == tripledescbcID {
return newTripleDESCBCCipher(iv, key, macKey, algs)
}
c := &streamPacketCipher{
mac: macModes[algs.MAC].new(macKey),
}
c.macResult = make([]byte, c.mac.Size())
var err error
c.cipher, err = cipherModes[algs.Cipher].createStream(key, iv)
if err != nil {
return nil, err
}
return c, nil
return cipherModes[algs.Cipher].create(key, iv, macKey, algs)
}
// generateKeyMaterial fills out with key material generated from tag, K, H
@@ -300,7 +313,7 @@ func readVersion(r io.Reader) ([]byte, error) {
var ok bool
var buf [1]byte
for len(versionString) < maxVersionStringBytes {
for length := 0; length < maxVersionStringBytes; length++ {
_, err := io.ReadFull(r, buf[:])
if err != nil {
return nil, err
@@ -308,6 +321,13 @@ func readVersion(r io.Reader) ([]byte, error) {
// The RFC says that the version should be terminated with \r\n
// but several SSH servers actually only send a \n.
if buf[0] == '\n' {
if !bytes.HasPrefix(versionString, []byte("SSH-")) {
// RFC 4253 says we need to ignore all version string lines
// except the one containing the SSH version (provided that
// all the lines do not exceed 255 bytes in total).
versionString = versionString[:0]
continue
}
ok = true
break
}