Update golang x/crypto dependencies (#2923) (#2951)

* Update golang x/crypto dependencies (#2923)

* Fix govendor for x/crupto curve25519 (#2925)

vendor/golang.org/x/crypto/curve25519/const_amd64.h

@@ -0,0 +1,8 @@
+// Copyright 2012 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.
+
+// This code was translated into a form compatible with 6a from the public
+// domain sources in SUPERCOP: https://bench.cr.yp.to/supercop.html
+
+#define REDMASK51     0x0007FFFFFFFFFFFF

vendor/golang.org/x/crypto/curve25519/const_amd64.s

@@ -3,12 +3,12 @@
 // license that can be found in the LICENSE file.
 
 // This code was translated into a form compatible with 6a from the public
-// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
+// domain sources in SUPERCOP: https://bench.cr.yp.to/supercop.html
 
 // +build amd64,!gccgo,!appengine
 
-DATA ·REDMASK51(SB)/8, $0x0007FFFFFFFFFFFF
+// These constants cannot be encoded in non-MOVQ immediates.
-GLOBL ·REDMASK51(SB), 8, $8
+// We access them directly from memory instead.
 
 DATA ·_121666_213(SB)/8, $996687872
 GLOBL ·_121666_213(SB), 8, $8

vendor/golang.org/x/crypto/curve25519/cswap_amd64.s

@@ -2,87 +2,64 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// This code was translated into a form compatible with 6a from the public
-// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
-
 // +build amd64,!gccgo,!appengine
 
-// func cswap(inout *[5]uint64, v uint64)
+// func cswap(inout *[4][5]uint64, v uint64)
 TEXT ·cswap(SB),7,$0
 	MOVQ inout+0(FP),DI
 	MOVQ v+8(FP),SI
 
-	CMPQ SI,$1
+	SUBQ $1, SI
-	MOVQ 0(DI),SI
+	NOTQ SI
-	MOVQ 80(DI),DX
+	MOVQ SI, X15
-	MOVQ 8(DI),CX
+	PSHUFD $0x44, X15, X15
-	MOVQ 88(DI),R8
+
-	MOVQ SI,R9
+	MOVOU 0(DI), X0
-	CMOVQEQ DX,SI
+	MOVOU 16(DI), X2
-	CMOVQEQ R9,DX
+	MOVOU 32(DI), X4
-	MOVQ CX,R9
+	MOVOU 48(DI), X6
-	CMOVQEQ R8,CX
+	MOVOU 64(DI), X8
-	CMOVQEQ R9,R8
+	MOVOU 80(DI), X1
-	MOVQ SI,0(DI)
+	MOVOU 96(DI), X3
-	MOVQ DX,80(DI)
+	MOVOU 112(DI), X5
-	MOVQ CX,8(DI)
+	MOVOU 128(DI), X7
-	MOVQ R8,88(DI)
+	MOVOU 144(DI), X9
-	MOVQ 16(DI),SI
+
-	MOVQ 96(DI),DX
+	MOVO X1, X10
-	MOVQ 24(DI),CX
+	MOVO X3, X11
-	MOVQ 104(DI),R8
+	MOVO X5, X12
-	MOVQ SI,R9
+	MOVO X7, X13
-	CMOVQEQ DX,SI
+	MOVO X9, X14
-	CMOVQEQ R9,DX
+
-	MOVQ CX,R9
+	PXOR X0, X10
-	CMOVQEQ R8,CX
+	PXOR X2, X11
-	CMOVQEQ R9,R8
+	PXOR X4, X12
-	MOVQ SI,16(DI)
+	PXOR X6, X13
-	MOVQ DX,96(DI)
+	PXOR X8, X14
-	MOVQ CX,24(DI)
+	PAND X15, X10
-	MOVQ R8,104(DI)
+	PAND X15, X11
-	MOVQ 32(DI),SI
+	PAND X15, X12
-	MOVQ 112(DI),DX
+	PAND X15, X13
-	MOVQ 40(DI),CX
+	PAND X15, X14
-	MOVQ 120(DI),R8
+	PXOR X10, X0
-	MOVQ SI,R9
+	PXOR X10, X1
-	CMOVQEQ DX,SI
+	PXOR X11, X2
-	CMOVQEQ R9,DX
+	PXOR X11, X3
-	MOVQ CX,R9
+	PXOR X12, X4
-	CMOVQEQ R8,CX
+	PXOR X12, X5
-	CMOVQEQ R9,R8
+	PXOR X13, X6
-	MOVQ SI,32(DI)
+	PXOR X13, X7
-	MOVQ DX,112(DI)
+	PXOR X14, X8
-	MOVQ CX,40(DI)
+	PXOR X14, X9
-	MOVQ R8,120(DI)
+
-	MOVQ 48(DI),SI
+	MOVOU X0, 0(DI)
-	MOVQ 128(DI),DX
+	MOVOU X2, 16(DI)
-	MOVQ 56(DI),CX
+	MOVOU X4, 32(DI)
-	MOVQ 136(DI),R8
+	MOVOU X6, 48(DI)
-	MOVQ SI,R9
+	MOVOU X8, 64(DI)
-	CMOVQEQ DX,SI
+	MOVOU X1, 80(DI)
-	CMOVQEQ R9,DX
+	MOVOU X3, 96(DI)
-	MOVQ CX,R9
+	MOVOU X5, 112(DI)
-	CMOVQEQ R8,CX
+	MOVOU X7, 128(DI)
-	CMOVQEQ R9,R8
+	MOVOU X9, 144(DI)
-	MOVQ SI,48(DI)
-	MOVQ DX,128(DI)
-	MOVQ CX,56(DI)
-	MOVQ R8,136(DI)
-	MOVQ 64(DI),SI
-	MOVQ 144(DI),DX
-	MOVQ 72(DI),CX
-	MOVQ 152(DI),R8
-	MOVQ SI,R9
-	CMOVQEQ DX,SI
-	CMOVQEQ R9,DX
-	MOVQ CX,R9
-	CMOVQEQ R8,CX
-	CMOVQEQ R9,R8
-	MOVQ SI,64(DI)
-	MOVQ DX,144(DI)
-	MOVQ CX,72(DI)
-	MOVQ R8,152(DI)
-	MOVQ DI,AX
-	MOVQ SI,DX
 	RET

vendor/golang.org/x/crypto/curve25519/curve25519.go

@@ -2,12 +2,16 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// We have a implementation in amd64 assembly so this code is only run on
+// We have an implementation in amd64 assembly so this code is only run on
 // non-amd64 platforms. The amd64 assembly does not support gccgo.
 // +build !amd64 gccgo appengine
 
 package curve25519
 
+import (
+	"encoding/binary"
+)
+
 // This code is a port of the public domain, "ref10" implementation of
 // curve25519 from SUPERCOP 20130419 by D. J. Bernstein.
 
@@ -50,17 +54,11 @@ func feCopy(dst, src *fieldElement) {
 //
 // Preconditions: b in {0,1}.
 func feCSwap(f, g *fieldElement, b int32) {
-	var x fieldElement
 	b = -b
-	for i := range x {
-		x[i] = b & (f[i] ^ g[i])
-	}
-
 	for i := range f {
-		f[i] ^= x[i]
+		t := b & (f[i] ^ g[i])
-	}
+		f[i] ^= t
-	for i := range g {
+		g[i] ^= t
-		g[i] ^= x[i]
 	}
 }
 
@@ -75,12 +73,7 @@ func load3(in []byte) int64 {
 
 // load4 reads a 32-bit, little-endian value from in.
 func load4(in []byte) int64 {
-	var r int64
+	return int64(binary.LittleEndian.Uint32(in))
-	r = int64(in[0])
-	r |= int64(in[1]) << 8
-	r |= int64(in[2]) << 16
-	r |= int64(in[3]) << 24
-	return r
 }
 
 func feFromBytes(dst *fieldElement, src *[32]byte) {

vendor/golang.org/x/crypto/curve25519/doc.go

@@ -3,7 +3,7 @@
 // license that can be found in the LICENSE file.
 
 // Package curve25519 provides an implementation of scalar multiplication on
-// the elliptic curve known as curve25519. See http://cr.yp.to/ecdh.html
+// the elliptic curve known as curve25519. See https://cr.yp.to/ecdh.html
 package curve25519 // import "golang.org/x/crypto/curve25519"
 
 // basePoint is the x coordinate of the generator of the curve.

vendor/golang.org/x/crypto/curve25519/freeze_amd64.s

@@ -3,10 +3,12 @@
 // license that can be found in the LICENSE file.
 
 // This code was translated into a form compatible with 6a from the public
-// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
+// domain sources in SUPERCOP: https://bench.cr.yp.to/supercop.html
 
 // +build amd64,!gccgo,!appengine
 
+#include "const_amd64.h"
+
 // func freeze(inout *[5]uint64)
 TEXT ·freeze(SB),7,$0-8
 	MOVQ inout+0(FP), DI
@@ -16,7 +18,7 @@ TEXT ·freeze(SB),7,$0-8
 	MOVQ 16(DI),CX
 	MOVQ 24(DI),R8
 	MOVQ 32(DI),R9
-	MOVQ ·REDMASK51(SB),AX
+	MOVQ $REDMASK51,AX
 	MOVQ AX,R10
 	SUBQ $18,R10
 	MOVQ $3,R11

vendor/golang.org/x/crypto/curve25519/ladderstep_amd64.s

@@ -3,10 +3,12 @@
 // license that can be found in the LICENSE file.
 
 // This code was translated into a form compatible with 6a from the public
-// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
+// domain sources in SUPERCOP: https://bench.cr.yp.to/supercop.html
 
 // +build amd64,!gccgo,!appengine
 
+#include "const_amd64.h"
+
 // func ladderstep(inout *[5][5]uint64)
 TEXT ·ladderstep(SB),0,$296-8
 	MOVQ inout+0(FP),DI
@@ -118,7 +120,7 @@ TEXT ·ladderstep(SB),0,$296-8
 	MULQ 72(SP)
 	ADDQ AX,R12
 	ADCQ DX,R13
-	MOVQ ·REDMASK51(SB),DX
+	MOVQ $REDMASK51,DX
 	SHLQ $13,CX:SI
 	ANDQ DX,SI
 	SHLQ $13,R9:R8
@@ -233,7 +235,7 @@ TEXT ·ladderstep(SB),0,$296-8
 	MULQ 32(SP)
 	ADDQ AX,R12
 	ADCQ DX,R13
-	MOVQ ·REDMASK51(SB),DX
+	MOVQ $REDMASK51,DX
 	SHLQ $13,CX:SI
 	ANDQ DX,SI
 	SHLQ $13,R9:R8
@@ -438,7 +440,7 @@ TEXT ·ladderstep(SB),0,$296-8
 	MULQ 72(SP)
 	ADDQ AX,R12
 	ADCQ DX,R13
-	MOVQ ·REDMASK51(SB),DX
+	MOVQ $REDMASK51,DX
 	SHLQ $13,CX:SI
 	ANDQ DX,SI
 	SHLQ $13,R9:R8
@@ -588,7 +590,7 @@ TEXT ·ladderstep(SB),0,$296-8
 	MULQ 32(SP)
 	ADDQ AX,R12
 	ADCQ DX,R13
-	MOVQ ·REDMASK51(SB),DX
+	MOVQ $REDMASK51,DX
 	SHLQ $13,CX:SI
 	ANDQ DX,SI
 	SHLQ $13,R9:R8
@@ -728,7 +730,7 @@ TEXT ·ladderstep(SB),0,$296-8
 	MULQ 152(DI)
 	ADDQ AX,R12
 	ADCQ DX,R13
-	MOVQ ·REDMASK51(SB),DX
+	MOVQ $REDMASK51,DX
 	SHLQ $13,CX:SI
 	ANDQ DX,SI
 	SHLQ $13,R9:R8
@@ -843,7 +845,7 @@ TEXT ·ladderstep(SB),0,$296-8
 	MULQ 192(DI)
 	ADDQ AX,R12
 	ADCQ DX,R13
-	MOVQ ·REDMASK51(SB),DX
+	MOVQ $REDMASK51,DX
 	SHLQ $13,CX:SI
 	ANDQ DX,SI
 	SHLQ $13,R9:R8
@@ -993,7 +995,7 @@ TEXT ·ladderstep(SB),0,$296-8
 	MULQ 32(DI)
 	ADDQ AX,R12
 	ADCQ DX,R13
-	MOVQ ·REDMASK51(SB),DX
+	MOVQ $REDMASK51,DX
 	SHLQ $13,CX:SI
 	ANDQ DX,SI
 	SHLQ $13,R9:R8
@@ -1143,7 +1145,7 @@ TEXT ·ladderstep(SB),0,$296-8
 	MULQ 112(SP)
 	ADDQ AX,R12
 	ADCQ DX,R13
-	MOVQ ·REDMASK51(SB),DX
+	MOVQ $REDMASK51,DX
 	SHLQ $13,CX:SI
 	ANDQ DX,SI
 	SHLQ $13,R9:R8
@@ -1329,7 +1331,7 @@ TEXT ·ladderstep(SB),0,$296-8
 	MULQ 192(SP)
 	ADDQ AX,R12
 	ADCQ DX,R13
-	MOVQ ·REDMASK51(SB),DX
+	MOVQ $REDMASK51,DX
 	SHLQ $13,CX:SI
 	ANDQ DX,SI
 	SHLQ $13,R9:R8

vendor/golang.org/x/crypto/curve25519/mul_amd64.s

@@ -3,10 +3,12 @@
 // license that can be found in the LICENSE file.
 
 // This code was translated into a form compatible with 6a from the public
-// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
+// domain sources in SUPERCOP: https://bench.cr.yp.to/supercop.html
 
 // +build amd64,!gccgo,!appengine
 
+#include "const_amd64.h"
+
 // func mul(dest, a, b *[5]uint64)
 TEXT ·mul(SB),0,$16-24
 	MOVQ dest+0(FP), DI
@@ -121,7 +123,7 @@ TEXT ·mul(SB),0,$16-24
 	MULQ 32(CX)
 	ADDQ AX,R14
 	ADCQ DX,R15
-	MOVQ ·REDMASK51(SB),SI
+	MOVQ $REDMASK51,SI
 	SHLQ $13,R9:R8
 	ANDQ SI,R8
 	SHLQ $13,R11:R10

vendor/golang.org/x/crypto/curve25519/square_amd64.s

@@ -3,10 +3,12 @@
 // license that can be found in the LICENSE file.
 
 // This code was translated into a form compatible with 6a from the public
-// domain sources in SUPERCOP: http://bench.cr.yp.to/supercop.html
+// domain sources in SUPERCOP: https://bench.cr.yp.to/supercop.html
 
 // +build amd64,!gccgo,!appengine
 
+#include "const_amd64.h"
+
 // func square(out, in *[5]uint64)
 TEXT ·square(SB),7,$0-16
 	MOVQ out+0(FP), DI
@@ -84,7 +86,7 @@ TEXT ·square(SB),7,$0-16
 	MULQ 32(SI)
 	ADDQ AX,R13
 	ADCQ DX,R14
-	MOVQ ·REDMASK51(SB),SI
+	MOVQ $REDMASK51,SI
 	SHLQ $13,R8:CX
 	ANDQ SI,CX
 	SHLQ $13,R10:R9

vendor/golang.org/x/crypto/ed25519/ed25519.go

@@ -3,20 +3,20 @@
 // license that can be found in the LICENSE file.
 
 // Package ed25519 implements the Ed25519 signature algorithm. See
-// http://ed25519.cr.yp.to/.
+// https://ed25519.cr.yp.to/.
 //
 // These functions are also compatible with the “Ed25519” function defined in
-// https://tools.ietf.org/html/draft-irtf-cfrg-eddsa-05.
+// RFC 8032.
 package ed25519
 
 // This code is a port of the public domain, “ref10” implementation of ed25519
 // from SUPERCOP.
 
 import (
+	"bytes"
 	"crypto"
 	cryptorand "crypto/rand"
 	"crypto/sha512"
-	"crypto/subtle"
 	"errors"
 	"io"
 	"strconv"
@@ -177,5 +177,5 @@ func Verify(publicKey PublicKey, message, sig []byte) bool {
 
 	var checkR [32]byte
 	R.ToBytes(&checkR)
-	return subtle.ConstantTimeCompare(sig[:32], checkR[:]) == 1
+	return bytes.Equal(sig[:32], checkR[:])
 }

vendor/golang.org/x/crypto/ssh/buffer.go

@@ -51,13 +51,12 @@ func (b *buffer) write(buf []byte) {
 }
 
 // eof closes the buffer. Reads from the buffer once all
-// the data has been consumed will receive os.EOF.
+// the data has been consumed will receive io.EOF.
-func (b *buffer) eof() error {
+func (b *buffer) eof() {
 	b.Cond.L.Lock()
 	b.closed = true
 	b.Cond.Signal()
 	b.Cond.L.Unlock()
-	return nil
 }
 
 // Read reads data from the internal buffer in buf.  Reads will block

vendor/golang.org/x/crypto/ssh/certs.go

@@ -251,10 +251,18 @@ type CertChecker struct {
 	// for user certificates.
 	SupportedCriticalOptions []string
 
-	// IsAuthority should return true if the key is recognized as
+	// IsUserAuthority should return true if the key is recognized as an
-	// an authority. This allows for certificates to be signed by other
+	// authority for the given user certificate. This allows for
-	// certificates.
+	// certificates to be signed by other certificates. This must be set
-	IsAuthority func(auth PublicKey) bool
+	// if this CertChecker will be checking user certificates.
+	IsUserAuthority func(auth PublicKey) bool
+
+	// IsHostAuthority should report whether the key is recognized as
+	// an authority for this host. This allows for certificates to be
+	// signed by other keys, and for those other keys to only be valid
+	// signers for particular hostnames. This must be set if this
+	// CertChecker will be checking host certificates.
+	IsHostAuthority func(auth PublicKey, address string) bool
 
 	// Clock is used for verifying time stamps. If nil, time.Now
 	// is used.
@@ -268,7 +276,7 @@ type CertChecker struct {
 	// HostKeyFallback is called when CertChecker.CheckHostKey encounters a
 	// public key that is not a certificate. It must implement host key
 	// validation or else, if nil, all such keys are rejected.
-	HostKeyFallback func(addr string, remote net.Addr, key PublicKey) error
+	HostKeyFallback HostKeyCallback
 
 	// IsRevoked is called for each certificate so that revocation checking
 	// can be implemented. It should return true if the given certificate
@@ -290,8 +298,17 @@ func (c *CertChecker) CheckHostKey(addr string, remote net.Addr, key PublicKey)
 	if cert.CertType != HostCert {
 		return fmt.Errorf("ssh: certificate presented as a host key has type %d", cert.CertType)
 	}
+	if !c.IsHostAuthority(cert.SignatureKey, addr) {
+		return fmt.Errorf("ssh: no authorities for hostname: %v", addr)
+	}
 
-	return c.CheckCert(addr, cert)
+	hostname, _, err := net.SplitHostPort(addr)
+	if err != nil {
+		return err
+	}
+
+	// Pass hostname only as principal for host certificates (consistent with OpenSSH)
+	return c.CheckCert(hostname, cert)
 }
 
 // Authenticate checks a user certificate. Authenticate can be used as
@@ -308,6 +325,9 @@ func (c *CertChecker) Authenticate(conn ConnMetadata, pubKey PublicKey) (*Permis
 	if cert.CertType != UserCert {
 		return nil, fmt.Errorf("ssh: cert has type %d", cert.CertType)
 	}
+	if !c.IsUserAuthority(cert.SignatureKey) {
+		return nil, fmt.Errorf("ssh: certificate signed by unrecognized authority")
+	}
 
 	if err := c.CheckCert(conn.User(), cert); err != nil {
 		return nil, err
@@ -356,10 +376,6 @@ func (c *CertChecker) CheckCert(principal string, cert *Certificate) error {
 		}
 	}
 
-	if !c.IsAuthority(cert.SignatureKey) {
-		return fmt.Errorf("ssh: certificate signed by unrecognized authority")
-	}
-
 	clock := c.Clock
 	if clock == nil {
 		clock = time.Now

vendor/golang.org/x/crypto/ssh/channel.go

@@ -461,8 +461,8 @@ func (m *mux) newChannel(chanType string, direction channelDirection, extraData
 		pending:          newBuffer(),
 		extPending:       newBuffer(),
 		direction:        direction,
-		incomingRequests: make(chan *Request, 16),
+		incomingRequests: make(chan *Request, chanSize),
-		msg:              make(chan interface{}, 16),
+		msg:              make(chan interface{}, chanSize),
 		chanType:         chanType,
 		extraData:        extraData,
 		mux:              m,

vendor/golang.org/x/crypto/ssh/cipher.go

@@ -135,6 +135,7 @@ 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 +151,14 @@ 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 +167,12 @@ 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 +197,17 @@ 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 +223,13 @@ 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 +246,37 @@ 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 +304,7 @@ type gcmCipher struct {
 	buf    []byte
 }
 
-func newGCMCipher(iv, key, macKey []byte) (packetCipher, error) {
+func newGCMCipher(iv, key []byte) (packetCipher, error) {
 	c, err := aes.NewCipher(key)
 	if err != nil {
 		return nil, err
@@ -344,7 +392,9 @@ 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)
 	}
 

vendor/golang.org/x/crypto/ssh/client.go

@@ -5,15 +5,17 @@
 package ssh
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
 	"net"
+	"os"
 	"sync"
 	"time"
 )
 
 // Client implements a traditional SSH client that supports shells,
-// subprocesses, port forwarding and tunneled dialing.
+// subprocesses, TCP port/streamlocal forwarding and tunneled dialing.
 type Client struct {
 	Conn
 
@@ -40,7 +42,7 @@ func (c *Client) HandleChannelOpen(channelType string) <-chan NewChannel {
 		return nil
 	}
 
-	ch = make(chan NewChannel, 16)
+	ch = make(chan NewChannel, chanSize)
 	c.channelHandlers[channelType] = ch
 	return ch
 }
@@ -59,6 +61,7 @@ func NewClient(c Conn, chans <-chan NewChannel, reqs <-chan *Request) *Client {
 		conn.forwards.closeAll()
 	}()
 	go conn.forwards.handleChannels(conn.HandleChannelOpen("forwarded-tcpip"))
+	go conn.forwards.handleChannels(conn.HandleChannelOpen("forwarded-streamlocal@openssh.com"))
 	return conn
 }
 
@@ -68,6 +71,11 @@ func NewClient(c Conn, chans <-chan NewChannel, reqs <-chan *Request) *Client {
 func NewClientConn(c net.Conn, addr string, config *ClientConfig) (Conn, <-chan NewChannel, <-chan *Request, error) {
 	fullConf := *config
 	fullConf.SetDefaults()
+	if fullConf.HostKeyCallback == nil {
+		c.Close()
+		return nil, nil, nil, errors.New("ssh: must specify HostKeyCallback")
+	}
+
 	conn := &connection{
 		sshConn: sshConn{conn: c},
 	}
@@ -97,13 +105,11 @@ func (c *connection) clientHandshake(dialAddress string, config *ClientConfig) e
 	c.transport = newClientTransport(
 		newTransport(c.sshConn.conn, config.Rand, true /* is client */),
 		c.clientVersion, c.serverVersion, config, dialAddress, c.sshConn.RemoteAddr())
-	if err := c.transport.requestInitialKeyChange(); err != nil {
+	if err := c.transport.waitSession(); err != nil {
 		return err
 	}
 
-	// We just did the key change, so the session ID is established.
 	c.sessionID = c.transport.getSessionID()
-
 	return c.clientAuthenticate(config)
 }
 
@@ -175,6 +181,17 @@ func Dial(network, addr string, config *ClientConfig) (*Client, error) {
 	return NewClient(c, chans, reqs), nil
 }
 
+// HostKeyCallback is the function type used for verifying server
+// keys.  A HostKeyCallback must return nil if the host key is OK, or
+// an error to reject it. It receives the hostname as passed to Dial
+// or NewClientConn. The remote address is the RemoteAddr of the
+// net.Conn underlying the the SSH connection.
+type HostKeyCallback func(hostname string, remote net.Addr, key PublicKey) error
+
+// BannerCallback is the function type used for treat the banner sent by
+// the server. A BannerCallback receives the message sent by the remote server.
+type BannerCallback func(message string) error
+
 // A ClientConfig structure is used to configure a Client. It must not be
 // modified after having been passed to an SSH function.
 type ClientConfig struct {
@@ -190,10 +207,18 @@ type ClientConfig struct {
 	// be used during authentication.
 	Auth []AuthMethod
 
-	// HostKeyCallback, if not nil, is called during the cryptographic
+	// HostKeyCallback is called during the cryptographic
-	// handshake to validate the server's host key. A nil HostKeyCallback
+	// handshake to validate the server's host key. The client
-	// implies that all host keys are accepted.
+	// configuration must supply this callback for the connection
-	HostKeyCallback func(hostname string, remote net.Addr, key PublicKey) error
+	// to succeed. The functions InsecureIgnoreHostKey or
+	// FixedHostKey can be used for simplistic host key checks.
+	HostKeyCallback HostKeyCallback
+
+	// BannerCallback is called during the SSH dance to display a custom
+	// server's message. The client configuration can supply this callback to
+	// handle it as wished. The function BannerDisplayStderr can be used for
+	// simplistic display on Stderr.
+	BannerCallback BannerCallback
 
 	// ClientVersion contains the version identification string that will
 	// be used for the connection. If empty, a reasonable default is used.
@@ -211,3 +236,43 @@ type ClientConfig struct {
 	// A Timeout of zero means no timeout.
 	Timeout time.Duration
 }
+
+// InsecureIgnoreHostKey returns a function that can be used for
+// ClientConfig.HostKeyCallback to accept any host key. It should
+// not be used for production code.
+func InsecureIgnoreHostKey() HostKeyCallback {
+	return func(hostname string, remote net.Addr, key PublicKey) error {
+		return nil
+	}
+}
+
+type fixedHostKey struct {
+	key PublicKey
+}
+
+func (f *fixedHostKey) check(hostname string, remote net.Addr, key PublicKey) error {
+	if f.key == nil {
+		return fmt.Errorf("ssh: required host key was nil")
+	}
+	if !bytes.Equal(key.Marshal(), f.key.Marshal()) {
+		return fmt.Errorf("ssh: host key mismatch")
+	}
+	return nil
+}
+
+// FixedHostKey returns a function for use in
+// ClientConfig.HostKeyCallback to accept only a specific host key.
+func FixedHostKey(key PublicKey) HostKeyCallback {
+	hk := &fixedHostKey{key}
+	return hk.check
+}
+
+// BannerDisplayStderr returns a function that can be used for
+// ClientConfig.BannerCallback to display banners on os.Stderr.
+func BannerDisplayStderr() BannerCallback {
+	return func(banner string) error {
+		_, err := os.Stderr.WriteString(banner)
+
+		return err
+	}
+}

vendor/golang.org/x/crypto/ssh/client_auth.go

@@ -30,8 +30,10 @@ func (c *connection) clientAuthenticate(config *ClientConfig) error {
 	// then any untried methods suggested by the server.
 	tried := make(map[string]bool)
 	var lastMethods []string
+
+	sessionID := c.transport.getSessionID()
 	for auth := AuthMethod(new(noneAuth)); auth != nil; {
-		ok, methods, err := auth.auth(c.transport.getSessionID(), config.User, c.transport, config.Rand)
+		ok, methods, err := auth.auth(sessionID, config.User, c.transport, config.Rand)
 		if err != nil {
 			return err
 		}
@@ -177,31 +179,26 @@ func (cb publicKeyCallback) method() string {
 }
 
 func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (bool, []string, error) {
-	// Authentication is performed in two stages. The first stage sends an
+	// Authentication is performed by sending an enquiry to test if a key is
-	// enquiry to test if each key is acceptable to the remote. The second
+	// acceptable to the remote. If the key is acceptable, the client will
-	// stage attempts to authenticate with the valid keys obtained in the
+	// attempt to authenticate with the valid key.  If not the client will repeat
-	// first stage.
+	// the process with the remaining keys.
 
 	signers, err := cb()
 	if err != nil {
 		return false, nil, err
 	}
-	var validKeys []Signer
-	for _, signer := range signers {
-		if ok, err := validateKey(signer.PublicKey(), user, c); ok {
-			validKeys = append(validKeys, signer)
-		} else {
-			if err != nil {
-				return false, nil, err
-			}
-		}
-	}
-
-	// methods that may continue if this auth is not successful.
 	var methods []string
-	for _, signer := range validKeys {
+	for _, signer := range signers {
-		pub := signer.PublicKey()
+		ok, err := validateKey(signer.PublicKey(), user, c)
+		if err != nil {
+			return false, nil, err
+		}
+		if !ok {
+			continue
+		}
 
+		pub := signer.PublicKey()
 		pubKey := pub.Marshal()
 		sign, err := signer.Sign(rand, buildDataSignedForAuth(session, userAuthRequestMsg{
 			User:    user,
@@ -234,13 +231,29 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
 		if err != nil {
 			return false, nil, err
 		}
-		if success {
+
+		// If authentication succeeds or the list of available methods does not
+		// contain the "publickey" method, do not attempt to authenticate with any
+		// other keys.  According to RFC 4252 Section 7, the latter can occur when
+		// additional authentication methods are required.
+		if success || !containsMethod(methods, cb.method()) {
 			return success, methods, err
 		}
 	}
+
 	return false, methods, nil
 }
 
+func containsMethod(methods []string, method string) bool {
+	for _, m := range methods {
+		if m == method {
+			return true
+		}
+	}
+
+	return false
+}
+
 // validateKey validates the key provided is acceptable to the server.
 func validateKey(key PublicKey, user string, c packetConn) (bool, error) {
 	pubKey := key.Marshal()
@@ -270,7 +283,9 @@ func confirmKeyAck(key PublicKey, c packetConn) (bool, error) {
 		}
 		switch packet[0] {
 		case msgUserAuthBanner:
-			// TODO(gpaul): add callback to present the banner to the user
+			if err := handleBannerResponse(c, packet); err != nil {
+				return false, err
+			}
 		case msgUserAuthPubKeyOk:
 			var msg userAuthPubKeyOkMsg
 			if err := Unmarshal(packet, &msg); err != nil {
@@ -312,7 +327,9 @@ func handleAuthResponse(c packetConn) (bool, []string, error) {
 
 		switch packet[0] {
 		case msgUserAuthBanner:
-			// TODO: add callback to present the banner to the user
+			if err := handleBannerResponse(c, packet); err != nil {
+				return false, nil, err
+			}
 		case msgUserAuthFailure:
 			var msg userAuthFailureMsg
 			if err := Unmarshal(packet, &msg); err != nil {
@@ -327,6 +344,24 @@ func handleAuthResponse(c packetConn) (bool, []string, error) {
 	}
 }
 
+func handleBannerResponse(c packetConn, packet []byte) error {
+	var msg userAuthBannerMsg
+	if err := Unmarshal(packet, &msg); err != nil {
+		return err
+	}
+
+	transport, ok := c.(*handshakeTransport)
+	if !ok {
+		return nil
+	}
+
+	if transport.bannerCallback != nil {
+		return transport.bannerCallback(msg.Message)
+	}
+
+	return nil
+}
+
 // KeyboardInteractiveChallenge should print questions, optionally
 // disabling echoing (e.g. for passwords), and return all the answers.
 // Challenge may be called multiple times in a single session. After
@@ -336,7 +371,7 @@ func handleAuthResponse(c packetConn) (bool, []string, error) {
 // both CLI and GUI environments.
 type KeyboardInteractiveChallenge func(user, instruction string, questions []string, echos []bool) (answers []string, err error)
 
-// KeyboardInteractive returns a AuthMethod using a prompt/response
+// KeyboardInteractive returns an AuthMethod using a prompt/response
 // sequence controlled by the server.
 func KeyboardInteractive(challenge KeyboardInteractiveChallenge) AuthMethod {
 	return challenge
@@ -372,7 +407,9 @@ func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packe
 		// like handleAuthResponse, but with less options.
 		switch packet[0] {
 		case msgUserAuthBanner:
-			// TODO: Print banners during userauth.
+			if err := handleBannerResponse(c, packet); err != nil {
+				return false, nil, err
+			}
 			continue
 		case msgUserAuthInfoRequest:
 			// OK

vendor/golang.org/x/crypto/ssh/common.go

@@ -9,6 +9,7 @@ import (
 	"crypto/rand"
 	"fmt"
 	"io"
+	"math"
 	"sync"
 
 	_ "crypto/sha1"
@@ -40,7 +41,7 @@ var supportedKexAlgos = []string{
 	kexAlgoDH14SHA1, kexAlgoDH1SHA1,
 }
 
-// supportedKexAlgos specifies the supported host-key algorithms (i.e. methods
+// supportedHostKeyAlgos specifies the supported host-key algorithms (i.e. methods
 // of authenticating servers) in preference order.
 var supportedHostKeyAlgos = []string{
 	CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01,
@@ -56,7 +57,7 @@ var supportedHostKeyAlgos = []string{
 // This is based on RFC 4253, section 6.4, but with hmac-md5 variants removed
 // because they have reached the end of their useful life.
 var supportedMACs = []string{
-	"hmac-sha2-256", "hmac-sha1", "hmac-sha1-96",
+	"hmac-sha2-256-etm@openssh.com", "hmac-sha2-256", "hmac-sha1", "hmac-sha1-96",
 }
 
 var supportedCompressions = []string{compressionNone}
@@ -104,6 +105,21 @@ type directionAlgorithms struct {
 	Compression string
 }
 
+// rekeyBytes returns a rekeying intervals in bytes.
+func (a *directionAlgorithms) rekeyBytes() int64 {
+	// According to RFC4344 block ciphers should rekey after
+	// 2^(BLOCKSIZE/4) blocks. For all AES flavors BLOCKSIZE is
+	// 128.
+	switch a.Cipher {
+	case "aes128-ctr", "aes192-ctr", "aes256-ctr", gcmCipherID, aes128cbcID:
+		return 16 * (1 << 32)
+
+	}
+
+	// For others, stick with RFC4253 recommendation to rekey after 1 Gb of data.
+	return 1 << 30
+}
+
 type algorithms struct {
 	kex     string
 	hostKey string
@@ -171,7 +187,7 @@ type Config struct {
 
 	// The maximum number of bytes sent or received after which a
 	// new key is negotiated. It must be at least 256. If
-	// unspecified, 1 gigabyte is used.
+	// unspecified, a size suitable for the chosen cipher is used.
 	RekeyThreshold uint64
 
 	// The allowed key exchanges algorithms. If unspecified then a
@@ -215,11 +231,12 @@ func (c *Config) SetDefaults() {
 	}
 
 	if c.RekeyThreshold == 0 {
-		// RFC 4253, section 9 suggests rekeying after 1G.
+		// cipher specific default
-		c.RekeyThreshold = 1 << 30
+	} else if c.RekeyThreshold < minRekeyThreshold {
-	}
-	if c.RekeyThreshold < minRekeyThreshold {
 		c.RekeyThreshold = minRekeyThreshold
+	} else if c.RekeyThreshold >= math.MaxInt64 {
+		// Avoid weirdness if somebody uses -1 as a threshold.
+		c.RekeyThreshold = math.MaxInt64
 	}
 }
 

vendor/golang.org/x/crypto/ssh/connection.go

@@ -25,7 +25,7 @@ type ConnMetadata interface {
 	// User returns the user ID for this connection.
 	User() string
 
-	// SessionID returns the sesson hash, also denoted by H.
+	// SessionID returns the session hash, also denoted by H.
 	SessionID() []byte
 
 	// ClientVersion returns the client's version string as hashed

vendor/golang.org/x/crypto/ssh/doc.go

@@ -14,5 +14,8 @@ others.
 References:
   [PROTOCOL.certkeys]: http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/PROTOCOL.certkeys?rev=HEAD
   [SSH-PARAMETERS]:    http://www.iana.org/assignments/ssh-parameters/ssh-parameters.xml#ssh-parameters-1
+
+This package does not fall under the stability promise of the Go language itself,
+so its API may be changed when pressing needs arise.
 */
 package ssh // import "golang.org/x/crypto/ssh"

vendor/golang.org/x/crypto/ssh/handshake.go

@@ -19,6 +19,11 @@ import (
 // messages are wrong when using ECDH.
 const debugHandshake = false
 
+// chanSize sets the amount of buffering SSH connections. This is
+// primarily for testing: setting chanSize=0 uncovers deadlocks more
+// quickly.
+const chanSize = 16
+
 // keyingTransport is a packet based transport that supports key
 // changes. It need not be thread-safe. It should pass through
 // msgNewKeys in both directions.
@@ -53,34 +58,65 @@ type handshakeTransport struct {
 	incoming  chan []byte
 	readError error
 
+	mu             sync.Mutex
+	writeError     error
+	sentInitPacket []byte
+	sentInitMsg    *kexInitMsg
+	pendingPackets [][]byte // Used when a key exchange is in progress.
+
+	// If the read loop wants to schedule a kex, it pings this
+	// channel, and the write loop will send out a kex
+	// message.
+	requestKex chan struct{}
+
+	// If the other side requests or confirms a kex, its kexInit
+	// packet is sent here for the write loop to find it.
+	startKex chan *pendingKex
+
 	// data for host key checking
-	hostKeyCallback func(hostname string, remote net.Addr, key PublicKey) error
+	hostKeyCallback HostKeyCallback
 	dialAddress     string
 	remoteAddr      net.Addr
 
-	readSinceKex uint64
+	// bannerCallback is non-empty if we are the client and it has been set in
+	// ClientConfig. In that case it is called during the user authentication
+	// dance to handle a custom server's message.
+	bannerCallback BannerCallback
 
-	// Protects the writing side of the connection
+	// Algorithms agreed in the last key exchange.
-	mu              sync.Mutex
+	algorithms *algorithms
-	cond            *sync.Cond
+
-	sentInitPacket  []byte
+	readPacketsLeft uint32
-	sentInitMsg     *kexInitMsg
+	readBytesLeft   int64
-	writtenSinceKex uint64
+
-	writeError      error
+	writePacketsLeft uint32
+	writeBytesLeft   int64
 
 	// The session ID or nil if first kex did not complete yet.
 	sessionID []byte
 }
 
+type pendingKex struct {
+	otherInit []byte
+	done      chan error
+}
+
 func newHandshakeTransport(conn keyingTransport, config *Config, clientVersion, serverVersion []byte) *handshakeTransport {
 	t := &handshakeTransport{
 		conn:          conn,
 		serverVersion: serverVersion,
 		clientVersion: clientVersion,
-		incoming:      make(chan []byte, 16),
+		incoming:      make(chan []byte, chanSize),
-		config:        config,
+		requestKex:    make(chan struct{}, 1),
+		startKex:      make(chan *pendingKex, 1),
+
+		config: config,
 	}
-	t.cond = sync.NewCond(&t.mu)
+	t.resetReadThresholds()
+	t.resetWriteThresholds()
+
+	// We always start with a mandatory key exchange.
+	t.requestKex <- struct{}{}
 	return t
 }
 
@@ -89,12 +125,14 @@ func newClientTransport(conn keyingTransport, clientVersion, serverVersion []byt
 	t.dialAddress = dialAddr
 	t.remoteAddr = addr
 	t.hostKeyCallback = config.HostKeyCallback
+	t.bannerCallback = config.BannerCallback
 	if config.HostKeyAlgorithms != nil {
 		t.hostKeyAlgorithms = config.HostKeyAlgorithms
 	} else {
 		t.hostKeyAlgorithms = supportedHostKeyAlgos
 	}
 	go t.readLoop()
+	go t.kexLoop()
 	return t
 }
 
@@ -102,6 +140,7 @@ func newServerTransport(conn keyingTransport, clientVersion, serverVersion []byt
 	t := newHandshakeTransport(conn, &config.Config, clientVersion, serverVersion)
 	t.hostKeys = config.hostKeys
 	go t.readLoop()
+	go t.kexLoop()
 	return t
 }
 
@@ -109,6 +148,20 @@ func (t *handshakeTransport) getSessionID() []byte {
 	return t.sessionID
 }
 
+// waitSession waits for the session to be established. This should be
+// the first thing to call after instantiating handshakeTransport.
+func (t *handshakeTransport) waitSession() error {
+	p, err := t.readPacket()
+	if err != nil {
+		return err
+	}
+	if p[0] != msgNewKeys {
+		return fmt.Errorf("ssh: first packet should be msgNewKeys")
+	}
+
+	return nil
+}
+
 func (t *handshakeTransport) id() string {
 	if len(t.hostKeys) > 0 {
 		return "server"
@@ -116,6 +169,20 @@ func (t *handshakeTransport) id() string {
 	return "client"
 }
 
+func (t *handshakeTransport) printPacket(p []byte, write bool) {
+	action := "got"
+	if write {
+		action = "sent"
+	}
+
+	if p[0] == msgChannelData || p[0] == msgChannelExtendedData {
+		log.Printf("%s %s data (packet %d bytes)", t.id(), action, len(p))
+	} else {
+		msg, err := decode(p)
+		log.Printf("%s %s %T %v (%v)", t.id(), action, msg, msg, err)
+	}
+}
+
 func (t *handshakeTransport) readPacket() ([]byte, error) {
 	p, ok := <-t.incoming
 	if !ok {
@@ -125,8 +192,10 @@ func (t *handshakeTransport) readPacket() ([]byte, error) {
 }
 
 func (t *handshakeTransport) readLoop() {
+	first := true
 	for {
-		p, err := t.readOnePacket()
+		p, err := t.readOnePacket(first)
+		first = false
 		if err != nil {
 			t.readError = err
 			close(t.incoming)
@@ -138,67 +207,217 @@ func (t *handshakeTransport) readLoop() {
 		t.incoming <- p
 	}
 
-	// If we can't read, declare the writing part dead too.
+	// Stop writers too.
-	t.mu.Lock()
+	t.recordWriteError(t.readError)
-	defer t.mu.Unlock()
+
-	if t.writeError == nil {
+	// Unblock the writer should it wait for this.
-		t.writeError = t.readError
+	close(t.startKex)
-	}
+
-	t.cond.Broadcast()
+	// Don't close t.requestKex; it's also written to from writePacket.
 }
 
-func (t *handshakeTransport) readOnePacket() ([]byte, error) {
+func (t *handshakeTransport) pushPacket(p []byte) error {
-	if t.readSinceKex > t.config.RekeyThreshold {
+	if debugHandshake {
-		if err := t.requestKeyChange(); err != nil {
+		t.printPacket(p, true)
-			return nil, err
+	}
+	return t.conn.writePacket(p)
+}
+
+func (t *handshakeTransport) getWriteError() error {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	return t.writeError
+}
+
+func (t *handshakeTransport) recordWriteError(err error) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if t.writeError == nil && err != nil {
+		t.writeError = err
+	}
+}
+
+func (t *handshakeTransport) requestKeyExchange() {
+	select {
+	case t.requestKex <- struct{}{}:
+	default:
+		// something already requested a kex, so do nothing.
+	}
+}
+
+func (t *handshakeTransport) resetWriteThresholds() {
+	t.writePacketsLeft = packetRekeyThreshold
+	if t.config.RekeyThreshold > 0 {
+		t.writeBytesLeft = int64(t.config.RekeyThreshold)
+	} else if t.algorithms != nil {
+		t.writeBytesLeft = t.algorithms.w.rekeyBytes()
+	} else {
+		t.writeBytesLeft = 1 << 30
+	}
+}
+
+func (t *handshakeTransport) kexLoop() {
+
+write:
+	for t.getWriteError() == nil {
+		var request *pendingKex
+		var sent bool
+
+		for request == nil || !sent {
+			var ok bool
+			select {
+			case request, ok = <-t.startKex:
+				if !ok {
+					break write
+				}
+			case <-t.requestKex:
+				break
+			}
+
+			if !sent {
+				if err := t.sendKexInit(); err != nil {
+					t.recordWriteError(err)
+					break
+				}
+				sent = true
+			}
 		}
+
+		if err := t.getWriteError(); err != nil {
+			if request != nil {
+				request.done <- err
+			}
+			break
+		}
+
+		// We're not servicing t.requestKex, but that is OK:
+		// we never block on sending to t.requestKex.
+
+		// We're not servicing t.startKex, but the remote end
+		// has just sent us a kexInitMsg, so it can't send
+		// another key change request, until we close the done
+		// channel on the pendingKex request.
+
+		err := t.enterKeyExchange(request.otherInit)
+
+		t.mu.Lock()
+		t.writeError = err
+		t.sentInitPacket = nil
+		t.sentInitMsg = nil
+
+		t.resetWriteThresholds()
+
+		// we have completed the key exchange. Since the
+		// reader is still blocked, it is safe to clear out
+		// the requestKex channel. This avoids the situation
+		// where: 1) we consumed our own request for the
+		// initial kex, and 2) the kex from the remote side
+		// caused another send on the requestKex channel,
+	clear:
+		for {
+			select {
+			case <-t.requestKex:
+				//
+			default:
+				break clear
+			}
+		}
+
+		request.done <- t.writeError
+
+		// kex finished. Push packets that we received while
+		// the kex was in progress. Don't look at t.startKex
+		// and don't increment writtenSinceKex: if we trigger
+		// another kex while we are still busy with the last
+		// one, things will become very confusing.
+		for _, p := range t.pendingPackets {
+			t.writeError = t.pushPacket(p)
+			if t.writeError != nil {
+				break
+			}
+		}
+		t.pendingPackets = t.pendingPackets[:0]
+		t.mu.Unlock()
 	}
 
+	// drain startKex channel. We don't service t.requestKex
+	// because nobody does blocking sends there.
+	go func() {
+		for init := range t.startKex {
+			init.done <- t.writeError
+		}
+	}()
+
+	// Unblock reader.
+	t.conn.Close()
+}
+
+// The protocol uses uint32 for packet counters, so we can't let them
+// reach 1<<32.  We will actually read and write more packets than
+// this, though: the other side may send more packets, and after we
+// hit this limit on writing we will send a few more packets for the
+// key exchange itself.
+const packetRekeyThreshold = (1 << 31)
+
+func (t *handshakeTransport) resetReadThresholds() {
+	t.readPacketsLeft = packetRekeyThreshold
+	if t.config.RekeyThreshold > 0 {
+		t.readBytesLeft = int64(t.config.RekeyThreshold)
+	} else if t.algorithms != nil {
+		t.readBytesLeft = t.algorithms.r.rekeyBytes()
+	} else {
+		t.readBytesLeft = 1 << 30
+	}
+}
+
+func (t *handshakeTransport) readOnePacket(first bool) ([]byte, error) {
 	p, err := t.conn.readPacket()
 	if err != nil {
 		return nil, err
 	}
 
-	t.readSinceKex += uint64(len(p))
+	if t.readPacketsLeft > 0 {
-	if debugHandshake {
+		t.readPacketsLeft--
-		if p[0] == msgChannelData || p[0] == msgChannelExtendedData {
+	} else {
-			log.Printf("%s got data (packet %d bytes)", t.id(), len(p))
+		t.requestKeyExchange()
-		} else {
-			msg, err := decode(p)
-			log.Printf("%s got %T %v (%v)", t.id(), msg, msg, err)
-		}
 	}
+
+	if t.readBytesLeft > 0 {
+		t.readBytesLeft -= int64(len(p))
+	} else {
+		t.requestKeyExchange()
+	}
+
+	if debugHandshake {
+		t.printPacket(p, false)
+	}
+
+	if first && p[0] != msgKexInit {
+		return nil, fmt.Errorf("ssh: first packet should be msgKexInit")
+	}
+
 	if p[0] != msgKexInit {
 		return p, nil
 	}
 
-	t.mu.Lock()
-
 	firstKex := t.sessionID == nil
 
-	err = t.enterKeyExchangeLocked(p)
+	kex := pendingKex{
-	if err != nil {
+		done:      make(chan error, 1),
-		// drop connection
+		otherInit: p,
-		t.conn.Close()
-		t.writeError = err
 	}
+	t.startKex <- &kex
+	err = <-kex.done
 
 	if debugHandshake {
 		log.Printf("%s exited key exchange (first %v), err %v", t.id(), firstKex, err)
 	}
 
-	// Unblock writers.
-	t.sentInitMsg = nil
-	t.sentInitPacket = nil
-	t.cond.Broadcast()
-	t.writtenSinceKex = 0
-	t.mu.Unlock()
-
 	if err != nil {
 		return nil, err
 	}
 
-	t.readSinceKex = 0
+	t.resetReadThresholds()
 
 	// By default, a key exchange is hidden from higher layers by
 	// translating it into msgIgnore.
@@ -213,61 +432,16 @@ func (t *handshakeTransport) readOnePacket() ([]byte, error) {
 	return successPacket, nil
 }
 
-// keyChangeCategory describes whether a key exchange is the first on a
+// sendKexInit sends a key change message.
-// connection, or a subsequent one.
+func (t *handshakeTransport) sendKexInit() error {
-type keyChangeCategory bool
-
-const (
-	firstKeyExchange      keyChangeCategory = true
-	subsequentKeyExchange keyChangeCategory = false
-)
-
-// sendKexInit sends a key change message, and returns the message
-// that was sent. After initiating the key change, all writes will be
-// blocked until the change is done, and a failed key change will
-// close the underlying transport. This function is safe for
-// concurrent use by multiple goroutines.
-func (t *handshakeTransport) sendKexInit(isFirst keyChangeCategory) error {
-	var err error
-
 	t.mu.Lock()
-	// If this is the initial key change, but we already have a sessionID,
+	defer t.mu.Unlock()
-	// then do nothing because the key exchange has already completed
-	// asynchronously.
-	if !isFirst || t.sessionID == nil {
-		_, _, err = t.sendKexInitLocked(isFirst)
-	}
-	t.mu.Unlock()
-	if err != nil {
-		return err
-	}
-	if isFirst {
-		if packet, err := t.readPacket(); err != nil {
-			return err
-		} else if packet[0] != msgNewKeys {
-			return unexpectedMessageError(msgNewKeys, packet[0])
-		}
-	}
-	return nil
-}
-
-func (t *handshakeTransport) requestInitialKeyChange() error {
-	return t.sendKexInit(firstKeyExchange)
-}
-
-func (t *handshakeTransport) requestKeyChange() error {
-	return t.sendKexInit(subsequentKeyExchange)
-}
-
-// sendKexInitLocked sends a key change message. t.mu must be locked
-// while this happens.
-func (t *handshakeTransport) sendKexInitLocked(isFirst keyChangeCategory) (*kexInitMsg, []byte, error) {
-	// kexInits may be sent either in response to the other side,
-	// or because our side wants to initiate a key change, so we
-	// may have already sent a kexInit. In that case, don't send a
-	// second kexInit.
 	if t.sentInitMsg != nil {
-		return t.sentInitMsg, t.sentInitPacket, nil
+		// kexInits may be sent either in response to the other side,
+		// or because our side wants to initiate a key change, so we
+		// may have already sent a kexInit. In that case, don't send a
+		// second kexInit.
+		return nil
 	}
 
 	msg := &kexInitMsg{
@@ -295,53 +469,65 @@ func (t *handshakeTransport) sendKexInitLocked(isFirst keyChangeCategory) (*kexI
 	packetCopy := make([]byte, len(packet))
 	copy(packetCopy, packet)
 
-	if err := t.conn.writePacket(packetCopy); err != nil {
+	if err := t.pushPacket(packetCopy); err != nil {
-		return nil, nil, err
+		return err
 	}
 
 	t.sentInitMsg = msg
 	t.sentInitPacket = packet
-	return msg, packet, nil
+
+	return nil
 }
 
 func (t *handshakeTransport) writePacket(p []byte) error {
-	t.mu.Lock()
-	defer t.mu.Unlock()
-
-	if t.writtenSinceKex > t.config.RekeyThreshold {
-		t.sendKexInitLocked(subsequentKeyExchange)
-	}
-	for t.sentInitMsg != nil && t.writeError == nil {
-		t.cond.Wait()
-	}
-	if t.writeError != nil {
-		return t.writeError
-	}
-	t.writtenSinceKex += uint64(len(p))
-
 	switch p[0] {
 	case msgKexInit:
 		return errors.New("ssh: only handshakeTransport can send kexInit")
 	case msgNewKeys:
 		return errors.New("ssh: only handshakeTransport can send newKeys")
-	default:
-		return t.conn.writePacket(p)
 	}
+
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if t.writeError != nil {
+		return t.writeError
+	}
+
+	if t.sentInitMsg != nil {
+		// Copy the packet so the writer can reuse the buffer.
+		cp := make([]byte, len(p))
+		copy(cp, p)
+		t.pendingPackets = append(t.pendingPackets, cp)
+		return nil
+	}
+
+	if t.writeBytesLeft > 0 {
+		t.writeBytesLeft -= int64(len(p))
+	} else {
+		t.requestKeyExchange()
+	}
+
+	if t.writePacketsLeft > 0 {
+		t.writePacketsLeft--
+	} else {
+		t.requestKeyExchange()
+	}
+
+	if err := t.pushPacket(p); err != nil {
+		t.writeError = err
+	}
+
+	return nil
 }
 
 func (t *handshakeTransport) Close() error {
 	return t.conn.Close()
 }
 
-// enterKeyExchange runs the key exchange. t.mu must be held while running this.
+func (t *handshakeTransport) enterKeyExchange(otherInitPacket []byte) error {
-func (t *handshakeTransport) enterKeyExchangeLocked(otherInitPacket []byte) error {
 	if debugHandshake {
 		log.Printf("%s entered key exchange", t.id())
 	}
-	myInit, myInitPacket, err := t.sendKexInitLocked(subsequentKeyExchange)
-	if err != nil {
-		return err
-	}
 
 	otherInit := &kexInitMsg{}
 	if err := Unmarshal(otherInitPacket, otherInit); err != nil {
@@ -352,20 +538,20 @@ func (t *handshakeTransport) enterKeyExchangeLocked(otherInitPacket []byte) erro
 		clientVersion: t.clientVersion,
 		serverVersion: t.serverVersion,
 		clientKexInit: otherInitPacket,
-		serverKexInit: myInitPacket,
+		serverKexInit: t.sentInitPacket,
 	}
 
 	clientInit := otherInit
-	serverInit := myInit
+	serverInit := t.sentInitMsg
 	if len(t.hostKeys) == 0 {
-		clientInit = myInit
+		clientInit, serverInit = serverInit, clientInit
-		serverInit = otherInit
 
-		magics.clientKexInit = myInitPacket
+		magics.clientKexInit = t.sentInitPacket
 		magics.serverKexInit = otherInitPacket
 	}
 
-	algs, err := findAgreedAlgorithms(clientInit, serverInit)
+	var err error
+	t.algorithms, err = findAgreedAlgorithms(clientInit, serverInit)
 	if err != nil {
 		return err
 	}
@@ -388,16 +574,16 @@ func (t *handshakeTransport) enterKeyExchangeLocked(otherInitPacket []byte) erro
 		}
 	}
 
-	kex, ok := kexAlgoMap[algs.kex]
+	kex, ok := kexAlgoMap[t.algorithms.kex]
 	if !ok {
-		return fmt.Errorf("ssh: unexpected key exchange algorithm %v", algs.kex)
+		return fmt.Errorf("ssh: unexpected key exchange algorithm %v", t.algorithms.kex)
 	}
 
 	var result *kexResult
 	if len(t.hostKeys) > 0 {
-		result, err = t.server(kex, algs, &magics)
+		result, err = t.server(kex, t.algorithms, &magics)
 	} else {
-		result, err = t.client(kex, algs, &magics)
+		result, err = t.client(kex, t.algorithms, &magics)
 	}
 
 	if err != nil {
@@ -409,7 +595,9 @@ func (t *handshakeTransport) enterKeyExchangeLocked(otherInitPacket []byte) erro
 	}
 	result.SessionID = t.sessionID
 
-	t.conn.prepareKeyChange(algs, result)
+	if err := t.conn.prepareKeyChange(t.algorithms, result); err != nil {
+		return err
+	}
 	if err = t.conn.writePacket([]byte{msgNewKeys}); err != nil {
 		return err
 	}
@@ -449,11 +637,9 @@ func (t *handshakeTransport) client(kex kexAlgorithm, algs *algorithms, magics *
 		return nil, err
 	}
 
-	if t.hostKeyCallback != nil {
+	err = t.hostKeyCallback(t.dialAddress, t.remoteAddr, hostKey)
-		err = t.hostKeyCallback(t.dialAddress, t.remoteAddr, hostKey)
+	if err != nil {
-		if err != nil {
+		return nil, err
-			return nil, err
-		}
 	}
 
 	return result, nil

vendor/golang.org/x/crypto/ssh/kex.go

@@ -383,8 +383,8 @@ func init() {
 	// 4253 and Oakley Group 2 in RFC 2409.
 	p, _ := new(big.Int).SetString("FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF", 16)
 	kexAlgoMap[kexAlgoDH1SHA1] = &dhGroup{
-		g: new(big.Int).SetInt64(2),
+		g:       new(big.Int).SetInt64(2),
-		p: p,
+		p:       p,
 		pMinus1: new(big.Int).Sub(p, bigOne),
 	}
 
@@ -393,8 +393,8 @@ func init() {
 	p, _ = new(big.Int).SetString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
 
 	kexAlgoMap[kexAlgoDH14SHA1] = &dhGroup{
-		g: new(big.Int).SetInt64(2),
+		g:       new(big.Int).SetInt64(2),
-		p: p,
+		p:       p,
 		pMinus1: new(big.Int).Sub(p, bigOne),
 	}
 

vendor/golang.org/x/crypto/ssh/keys.go

@@ -10,10 +10,13 @@ import (
 	"crypto/dsa"
 	"crypto/ecdsa"
 	"crypto/elliptic"
+	"crypto/md5"
 	"crypto/rsa"
+	"crypto/sha256"
 	"crypto/x509"
 	"encoding/asn1"
 	"encoding/base64"
+	"encoding/hex"
 	"encoding/pem"
 	"errors"
 	"fmt"
@@ -364,6 +367,17 @@ func (r *dsaPublicKey) Type() string {
 	return "ssh-dss"
 }
 
+func checkDSAParams(param *dsa.Parameters) error {
+	// SSH specifies FIPS 186-2, which only provided a single size
+	// (1024 bits) DSA key. FIPS 186-3 allows for larger key
+	// sizes, which would confuse SSH.
+	if l := param.P.BitLen(); l != 1024 {
+		return fmt.Errorf("ssh: unsupported DSA key size %d", l)
+	}
+
+	return nil
+}
+
 // parseDSA parses an DSA key according to RFC 4253, section 6.6.
 func parseDSA(in []byte) (out PublicKey, rest []byte, err error) {
 	var w struct {
@@ -374,13 +388,18 @@ func parseDSA(in []byte) (out PublicKey, rest []byte, err error) {
 		return nil, nil, err
 	}
 
+	param := dsa.Parameters{
+		P: w.P,
+		Q: w.Q,
+		G: w.G,
+	}
+	if err := checkDSAParams(&param); err != nil {
+		return nil, nil, err
+	}
+
 	key := &dsaPublicKey{
-		Parameters: dsa.Parameters{
+		Parameters: param,
-			P: w.P,
+		Y:          w.Y,
-			Q: w.Q,
-			G: w.G,
-		},
-		Y: w.Y,
 	}
 	return key, w.Rest, nil
 }
@@ -627,19 +646,28 @@ func (k *ecdsaPublicKey) CryptoPublicKey() crypto.PublicKey {
 }
 
 // NewSignerFromKey takes an *rsa.PrivateKey, *dsa.PrivateKey,
-// *ecdsa.PrivateKey or any other crypto.Signer and returns a corresponding
+// *ecdsa.PrivateKey or any other crypto.Signer and returns a
-// Signer instance. ECDSA keys must use P-256, P-384 or P-521.
+// corresponding Signer instance. ECDSA keys must use P-256, P-384 or
+// P-521. DSA keys must use parameter size L1024N160.
 func NewSignerFromKey(key interface{}) (Signer, error) {
 	switch key := key.(type) {
 	case crypto.Signer:
 		return NewSignerFromSigner(key)
 	case *dsa.PrivateKey:
-		return &dsaPrivateKey{key}, nil
+		return newDSAPrivateKey(key)
 	default:
 		return nil, fmt.Errorf("ssh: unsupported key type %T", key)
 	}
 }
 
+func newDSAPrivateKey(key *dsa.PrivateKey) (Signer, error) {
+	if err := checkDSAParams(&key.PublicKey.Parameters); err != nil {
+		return nil, err
+	}
+
+	return &dsaPrivateKey{key}, nil
+}
+
 type wrappedSigner struct {
 	signer crypto.Signer
 	pubKey PublicKey
@@ -753,6 +781,18 @@ func ParsePrivateKey(pemBytes []byte) (Signer, error) {
 	return NewSignerFromKey(key)
 }
 
+// ParsePrivateKeyWithPassphrase returns a Signer from a PEM encoded private
+// key and passphrase. It supports the same keys as
+// ParseRawPrivateKeyWithPassphrase.
+func ParsePrivateKeyWithPassphrase(pemBytes, passPhrase []byte) (Signer, error) {
+	key, err := ParseRawPrivateKeyWithPassphrase(pemBytes, passPhrase)
+	if err != nil {
+		return nil, err
+	}
+
+	return NewSignerFromKey(key)
+}
+
 // encryptedBlock tells whether a private key is
 // encrypted by examining its Proc-Type header
 // for a mention of ENCRYPTED
@@ -787,6 +827,43 @@ func ParseRawPrivateKey(pemBytes []byte) (interface{}, error) {
 	}
 }
 
+// ParseRawPrivateKeyWithPassphrase returns a private key decrypted with
+// passphrase from a PEM encoded private key. If wrong passphrase, return
+// x509.IncorrectPasswordError.
+func ParseRawPrivateKeyWithPassphrase(pemBytes, passPhrase []byte) (interface{}, error) {
+	block, _ := pem.Decode(pemBytes)
+	if block == nil {
+		return nil, errors.New("ssh: no key found")
+	}
+	buf := block.Bytes
+
+	if encryptedBlock(block) {
+		if x509.IsEncryptedPEMBlock(block) {
+			var err error
+			buf, err = x509.DecryptPEMBlock(block, passPhrase)
+			if err != nil {
+				if err == x509.IncorrectPasswordError {
+					return nil, err
+				}
+				return nil, fmt.Errorf("ssh: cannot decode encrypted private keys: %v", err)
+			}
+		}
+	}
+
+	switch block.Type {
+	case "RSA PRIVATE KEY":
+		return x509.ParsePKCS1PrivateKey(buf)
+	case "EC PRIVATE KEY":
+		return x509.ParseECPrivateKey(buf)
+	case "DSA PRIVATE KEY":
+		return ParseDSAPrivateKey(buf)
+	case "OPENSSH PRIVATE KEY":
+		return parseOpenSSHPrivateKey(buf)
+	default:
+		return nil, fmt.Errorf("ssh: unsupported key type %q", block.Type)
+	}
+}
+
 // ParseDSAPrivateKey returns a DSA private key from its ASN.1 DER encoding, as
 // specified by the OpenSSL DSA man page.
 func ParseDSAPrivateKey(der []byte) (*dsa.PrivateKey, error) {
@@ -795,8 +872,8 @@ func ParseDSAPrivateKey(der []byte) (*dsa.PrivateKey, error) {
 		P       *big.Int
 		Q       *big.Int
 		G       *big.Int
-		Priv    *big.Int
 		Pub     *big.Int
+		Priv    *big.Int
 	}
 	rest, err := asn1.Unmarshal(der, &k)
 	if err != nil {
@@ -813,15 +890,15 @@ func ParseDSAPrivateKey(der []byte) (*dsa.PrivateKey, error) {
 				Q: k.Q,
 				G: k.G,
 			},
-			Y: k.Priv,
+			Y: k.Pub,
 		},
-		X: k.Pub,
+		X: k.Priv,
 	}, nil
 }
 
 // Implemented based on the documentation at
 // https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.key
-func parseOpenSSHPrivateKey(key []byte) (*ed25519.PrivateKey, error) {
+func parseOpenSSHPrivateKey(key []byte) (crypto.PrivateKey, error) {
 	magic := append([]byte("openssh-key-v1"), 0)
 	if !bytes.Equal(magic, key[0:len(magic)]) {
 		return nil, errors.New("ssh: invalid openssh private key format")
@@ -841,14 +918,15 @@ func parseOpenSSHPrivateKey(key []byte) (*ed25519.PrivateKey, error) {
 		return nil, err
 	}
 
+	if w.KdfName != "none" || w.CipherName != "none" {
+		return nil, errors.New("ssh: cannot decode encrypted private keys")
+	}
+
 	pk1 := struct {
 		Check1  uint32
 		Check2  uint32
 		Keytype string
-		Pub     []byte
+		Rest    []byte `ssh:"rest"`
-		Priv    []byte
-		Comment string
-		Pad     []byte `ssh:"rest"`
 	}{}
 
 	if err := Unmarshal(w.PrivKeyBlock, &pk1); err != nil {
@@ -859,22 +937,95 @@ func parseOpenSSHPrivateKey(key []byte) (*ed25519.PrivateKey, error) {
 		return nil, errors.New("ssh: checkint mismatch")
 	}
 
-	// we only handle ed25519 keys currently
+	// we only handle ed25519 and rsa keys currently
-	if pk1.Keytype != KeyAlgoED25519 {
+	switch pk1.Keytype {
+	case KeyAlgoRSA:
+		// https://github.com/openssh/openssh-portable/blob/master/sshkey.c#L2760-L2773
+		key := struct {
+			N       *big.Int
+			E       *big.Int
+			D       *big.Int
+			Iqmp    *big.Int
+			P       *big.Int
+			Q       *big.Int
+			Comment string
+			Pad     []byte `ssh:"rest"`
+		}{}
+
+		if err := Unmarshal(pk1.Rest, &key); err != nil {
+			return nil, err
+		}
+
+		for i, b := range key.Pad {
+			if int(b) != i+1 {
+				return nil, errors.New("ssh: padding not as expected")
+			}
+		}
+
+		pk := &rsa.PrivateKey{
+			PublicKey: rsa.PublicKey{
+				N: key.N,
+				E: int(key.E.Int64()),
+			},
+			D:      key.D,
+			Primes: []*big.Int{key.P, key.Q},
+		}
+
+		if err := pk.Validate(); err != nil {
+			return nil, err
+		}
+
+		pk.Precompute()
+
+		return pk, nil
+	case KeyAlgoED25519:
+		key := struct {
+			Pub     []byte
+			Priv    []byte
+			Comment string
+			Pad     []byte `ssh:"rest"`
+		}{}
+
+		if err := Unmarshal(pk1.Rest, &key); err != nil {
+			return nil, err
+		}
+
+		if len(key.Priv) != ed25519.PrivateKeySize {
+			return nil, errors.New("ssh: private key unexpected length")
+		}
+
+		for i, b := range key.Pad {
+			if int(b) != i+1 {
+				return nil, errors.New("ssh: padding not as expected")
+			}
+		}
+
+		pk := ed25519.PrivateKey(make([]byte, ed25519.PrivateKeySize))
+		copy(pk, key.Priv)
+		return &pk, nil
+	default:
 		return nil, errors.New("ssh: unhandled key type")
 	}
-
+}
-	for i, b := range pk1.Pad {
+
-		if int(b) != i+1 {
+// FingerprintLegacyMD5 returns the user presentation of the key's
-			return nil, errors.New("ssh: padding not as expected")
+// fingerprint as described by RFC 4716 section 4.
-		}
+func FingerprintLegacyMD5(pubKey PublicKey) string {
-	}
+	md5sum := md5.Sum(pubKey.Marshal())
-
+	hexarray := make([]string, len(md5sum))
-	if len(pk1.Priv) != ed25519.PrivateKeySize {
+	for i, c := range md5sum {
-		return nil, errors.New("ssh: private key unexpected length")
+		hexarray[i] = hex.EncodeToString([]byte{c})
-	}
+	}
-
+	return strings.Join(hexarray, ":")
-	pk := ed25519.PrivateKey(make([]byte, ed25519.PrivateKeySize))
+}
-	copy(pk, pk1.Priv)
+
-	return &pk, nil
+// FingerprintSHA256 returns the user presentation of the key's
+// fingerprint as unpadded base64 encoded sha256 hash.
+// This format was introduced from OpenSSH 6.8.
+// https://www.openssh.com/txt/release-6.8
+// https://tools.ietf.org/html/rfc4648#section-3.2 (unpadded base64 encoding)
+func FingerprintSHA256(pubKey PublicKey) string {
+	sha256sum := sha256.Sum256(pubKey.Marshal())
+	hash := base64.RawStdEncoding.EncodeToString(sha256sum[:])
+	return "SHA256:" + hash
 }

vendor/golang.org/x/crypto/ssh/mac.go

@@ -15,6 +15,7 @@ import (
 
 type macMode struct {
 	keySize int
+	etm     bool
 	new     func(key []byte) hash.Hash
 }
 
@@ -45,13 +46,16 @@ func (t truncatingMAC) Size() int {
 func (t truncatingMAC) BlockSize() int { return t.hmac.BlockSize() }
 
 var macModes = map[string]*macMode{
-	"hmac-sha2-256": {32, func(key []byte) hash.Hash {
+	"hmac-sha2-256-etm@openssh.com": {32, true, func(key []byte) hash.Hash {
 		return hmac.New(sha256.New, key)
 	}},
-	"hmac-sha1": {20, func(key []byte) hash.Hash {
+	"hmac-sha2-256": {32, false, func(key []byte) hash.Hash {
+		return hmac.New(sha256.New, key)
+	}},
+	"hmac-sha1": {20, false, func(key []byte) hash.Hash {
 		return hmac.New(sha1.New, key)
 	}},
-	"hmac-sha1-96": {20, func(key []byte) hash.Hash {
+	"hmac-sha1-96": {20, false, func(key []byte) hash.Hash {
 		return truncatingMAC{12, hmac.New(sha1.New, key)}
 	}},
 }

vendor/golang.org/x/crypto/ssh/messages.go

@@ -23,10 +23,6 @@ const (
 	msgUnimplemented = 3
 	msgDebug         = 4
 	msgNewKeys       = 21
-
-	// Standard authentication messages
-	msgUserAuthSuccess = 52
-	msgUserAuthBanner  = 53
 )
 
 // SSH messages:
@@ -137,6 +133,18 @@ type userAuthFailureMsg struct {
 	PartialSuccess bool
 }
 
+// See RFC 4252, section 5.1
+const msgUserAuthSuccess = 52
+
+// See RFC 4252, section 5.4
+const msgUserAuthBanner = 53
+
+type userAuthBannerMsg struct {
+	Message string `sshtype:"53"`
+	// unused, but required to allow message parsing
+	Language string
+}
+
 // See RFC 4256, section 3.2
 const msgUserAuthInfoRequest = 60
 const msgUserAuthInfoResponse = 61

vendor/golang.org/x/crypto/ssh/mux.go

@@ -116,9 +116,9 @@ func (m *mux) Wait() error {
 func newMux(p packetConn) *mux {
 	m := &mux{
 		conn:             p,
-		incomingChannels: make(chan NewChannel, 16),
+		incomingChannels: make(chan NewChannel, chanSize),
 		globalResponses:  make(chan interface{}, 1),
-		incomingRequests: make(chan *Request, 16),
+		incomingRequests: make(chan *Request, chanSize),
 		errCond:          newCond(),
 	}
 	if debugMux {

vendor/golang.org/x/crypto/ssh/server.go

@@ -10,26 +10,38 @@ import (
 	"fmt"
 	"io"
 	"net"
+	"strings"
 )
 
 // The Permissions type holds fine-grained permissions that are
-// specific to a user or a specific authentication method for a
+// specific to a user or a specific authentication method for a user.
-// user. Permissions, except for "source-address", must be enforced in
+// The Permissions value for a successful authentication attempt is
-// the server application layer, after successful authentication. The
+// available in ServerConn, so it can be used to pass information from
-// Permissions are passed on in ServerConn so a server implementation
+// the user-authentication phase to the application layer.
-// can honor them.
 type Permissions struct {
-	// Critical options restrict default permissions. Common
+	// CriticalOptions indicate restrictions to the default
-	// restrictions are "source-address" and "force-command". If
+	// permissions, and are typically used in conjunction with
-	// the server cannot enforce the restriction, or does not
+	// user certificates. The standard for SSH certificates
-	// recognize it, the user should not authenticate.
+	// defines "force-command" (only allow the given command to
+	// execute) and "source-address" (only allow connections from
+	// the given address). The SSH package currently only enforces
+	// the "source-address" critical option. It is up to server
+	// implementations to enforce other critical options, such as
+	// "force-command", by checking them after the SSH handshake
+	// is successful. In general, SSH servers should reject
+	// connections that specify critical options that are unknown
+	// or not supported.
 	CriticalOptions map[string]string
 
 	// Extensions are extra functionality that the server may
-	// offer on authenticated connections. Common extensions are
+	// offer on authenticated connections. Lack of support for an
-	// "permit-agent-forwarding", "permit-X11-forwarding". Lack of
+	// extension does not preclude authenticating a user. Common
-	// support for an extension does not preclude authenticating a
+	// extensions are "permit-agent-forwarding",
-	// user.
+	// "permit-X11-forwarding". The Go SSH library currently does
+	// not act on any extension, and it is up to server
+	// implementations to honor them. Extensions can be used to
+	// pass data from the authentication callbacks to the server
+	// application layer.
 	Extensions map[string]string
 }
 
@@ -44,13 +56,24 @@ type ServerConfig struct {
 	// authenticating.
 	NoClientAuth bool
 
+	// MaxAuthTries specifies the maximum number of authentication attempts
+	// permitted per connection. If set to a negative number, the number of
+	// attempts are unlimited. If set to zero, the number of attempts are limited
+	// to 6.
+	MaxAuthTries int
+
 	// PasswordCallback, if non-nil, is called when a user
 	// attempts to authenticate using a password.
 	PasswordCallback func(conn ConnMetadata, password []byte) (*Permissions, error)
 
-	// PublicKeyCallback, if non-nil, is called when a client attempts public
+	// PublicKeyCallback, if non-nil, is called when a client
-	// key authentication. It must return true if the given public key is
+	// offers a public key for authentication. It must return a nil error
-	// valid for the given user. For example, see CertChecker.Authenticate.
+	// if the given public key can be used to authenticate the
+	// given user. For example, see CertChecker.Authenticate. A
+	// call to this function does not guarantee that the key
+	// offered is in fact used to authenticate. To record any data
+	// depending on the public key, store it inside a
+	// Permissions.Extensions entry.
 	PublicKeyCallback func(conn ConnMetadata, key PublicKey) (*Permissions, error)
 
 	// KeyboardInteractiveCallback, if non-nil, is called when
@@ -72,6 +95,10 @@ type ServerConfig struct {
 	// Note that RFC 4253 section 4.2 requires that this string start with
 	// "SSH-2.0-".
 	ServerVersion string
+
+	// BannerCallback, if present, is called and the return string is sent to
+	// the client after key exchange completed but before authentication.
+	BannerCallback func(conn ConnMetadata) string
 }
 
 // AddHostKey adds a private key as a host key. If an existing host
@@ -142,6 +169,10 @@ type ServerConn struct {
 func NewServerConn(c net.Conn, config *ServerConfig) (*ServerConn, <-chan NewChannel, <-chan *Request, error) {
 	fullConf := *config
 	fullConf.SetDefaults()
+	if fullConf.MaxAuthTries == 0 {
+		fullConf.MaxAuthTries = 6
+	}
+
 	s := &connection{
 		sshConn: sshConn{conn: c},
 	}
@@ -188,7 +219,7 @@ func (s *connection) serverHandshake(config *ServerConfig) (*Permissions, error)
 	tr := newTransport(s.sshConn.conn, config.Rand, false /* not client */)
 	s.transport = newServerTransport(tr, s.clientVersion, s.serverVersion, config)
 
-	if err := s.transport.requestInitialKeyChange(); err != nil {
+	if err := s.transport.waitSession(); err != nil {
 		return nil, err
 	}
 
@@ -231,7 +262,7 @@ func isAcceptableAlgo(algo string) bool {
 	return false
 }
 
-func checkSourceAddress(addr net.Addr, sourceAddr string) error {
+func checkSourceAddress(addr net.Addr, sourceAddrs string) error {
 	if addr == nil {
 		return errors.New("ssh: no address known for client, but source-address match required")
 	}
@@ -241,33 +272,71 @@ func checkSourceAddress(addr net.Addr, sourceAddr string) error {
 		return fmt.Errorf("ssh: remote address %v is not an TCP address when checking source-address match", addr)
 	}
 
-	if allowedIP := net.ParseIP(sourceAddr); allowedIP != nil {
+	for _, sourceAddr := range strings.Split(sourceAddrs, ",") {
-		if bytes.Equal(allowedIP, tcpAddr.IP) {
+		if allowedIP := net.ParseIP(sourceAddr); allowedIP != nil {
-			return nil
+			if allowedIP.Equal(tcpAddr.IP) {
-		}
+				return nil
-	} else {
+			}
-		_, ipNet, err := net.ParseCIDR(sourceAddr)
+		} else {
-		if err != nil {
+			_, ipNet, err := net.ParseCIDR(sourceAddr)
-			return fmt.Errorf("ssh: error parsing source-address restriction %q: %v", sourceAddr, err)
+			if err != nil {
-		}
+				return fmt.Errorf("ssh: error parsing source-address restriction %q: %v", sourceAddr, err)
+			}
 
-		if ipNet.Contains(tcpAddr.IP) {
+			if ipNet.Contains(tcpAddr.IP) {
-			return nil
+				return nil
+			}
 		}
 	}
 
 	return fmt.Errorf("ssh: remote address %v is not allowed because of source-address restriction", addr)
 }
 
+// ServerAuthError implements the error interface. It appends any authentication
+// errors that may occur, and is returned if all of the authentication methods
+// provided by the user failed to authenticate.
+type ServerAuthError struct {
+	// Errors contains authentication errors returned by the authentication
+	// callback methods.
+	Errors []error
+}
+
+func (l ServerAuthError) Error() string {
+	var errs []string
+	for _, err := range l.Errors {
+		errs = append(errs, err.Error())
+	}
+	return "[" + strings.Join(errs, ", ") + "]"
+}
+
 func (s *connection) serverAuthenticate(config *ServerConfig) (*Permissions, error) {
-	var err error
+	sessionID := s.transport.getSessionID()
 	var cache pubKeyCache
 	var perms *Permissions
 
+	authFailures := 0
+	var authErrs []error
+
 userAuthLoop:
 	for {
+		if authFailures >= config.MaxAuthTries && config.MaxAuthTries > 0 {
+			discMsg := &disconnectMsg{
+				Reason:  2,
+				Message: "too many authentication failures",
+			}
+
+			if err := s.transport.writePacket(Marshal(discMsg)); err != nil {
+				return nil, err
+			}
+
+			return nil, discMsg
+		}
+
 		var userAuthReq userAuthRequestMsg
 		if packet, err := s.transport.readPacket(); err != nil {
+			if err == io.EOF {
+				return nil, &ServerAuthError{Errors: authErrs}
+			}
 			return nil, err
 		} else if err = Unmarshal(packet, &userAuthReq); err != nil {
 			return nil, err
@@ -278,6 +347,19 @@ userAuthLoop:
 		}
 
 		s.user = userAuthReq.User
+
+		if authFailures == 0 && config.BannerCallback != nil {
+			msg := config.BannerCallback(s)
+			if msg != "" {
+				bannerMsg := &userAuthBannerMsg{
+					Message: msg,
+				}
+				if err := s.transport.writePacket(Marshal(bannerMsg)); err != nil {
+					return nil, err
+				}
+			}
+		}
+
 		perms = nil
 		authErr := errors.New("no auth passed yet")
 
@@ -286,6 +368,11 @@ userAuthLoop:
 			if config.NoClientAuth {
 				authErr = nil
 			}
+
+			// allow initial attempt of 'none' without penalty
+			if authFailures == 0 {
+				authFailures--
+			}
 		case "password":
 			if config.PasswordCallback == nil {
 				authErr = errors.New("ssh: password auth not configured")
@@ -357,6 +444,7 @@ userAuthLoop:
 			if isQuery {
 				// The client can query if the given public key
 				// would be okay.
+
 				if len(payload) > 0 {
 					return nil, parseError(msgUserAuthRequest)
 				}
@@ -385,7 +473,7 @@ userAuthLoop:
 				if !isAcceptableAlgo(sig.Format) {
 					break
 				}
-				signedData := buildDataSignedForAuth(s.transport.getSessionID(), userAuthReq, algoBytes, pubKeyData)
+				signedData := buildDataSignedForAuth(sessionID, userAuthReq, algoBytes, pubKeyData)
 
 				if err := pubKey.Verify(signedData, sig); err != nil {
 					return nil, err
@@ -398,6 +486,8 @@ userAuthLoop:
 			authErr = fmt.Errorf("ssh: unknown method %q", userAuthReq.Method)
 		}
 
+		authErrs = append(authErrs, authErr)
+
 		if config.AuthLogCallback != nil {
 			config.AuthLogCallback(s, userAuthReq.Method, authErr)
 		}
@@ -406,6 +496,8 @@ userAuthLoop:
 			break userAuthLoop
 		}
 
+		authFailures++
+
 		var failureMsg userAuthFailureMsg
 		if config.PasswordCallback != nil {
 			failureMsg.Methods = append(failureMsg.Methods, "password")
@@ -421,12 +513,12 @@ userAuthLoop:
 			return nil, errors.New("ssh: no authentication methods configured but NoClientAuth is also false")
 		}
 
-		if err = s.transport.writePacket(Marshal(&failureMsg)); err != nil {
+		if err := s.transport.writePacket(Marshal(&failureMsg)); err != nil {
 			return nil, err
 		}
 	}
 
-	if err = s.transport.writePacket([]byte{msgUserAuthSuccess}); err != nil {
+	if err := s.transport.writePacket([]byte{msgUserAuthSuccess}); err != nil {
 		return nil, err
 	}
 	return perms, nil

vendor/golang.org/x/crypto/ssh/session.go

@@ -231,6 +231,26 @@ func (s *Session) RequestSubsystem(subsystem string) error {
 	return err
 }
 
+// RFC 4254 Section 6.7.
+type ptyWindowChangeMsg struct {
+	Columns uint32
+	Rows    uint32
+	Width   uint32
+	Height  uint32
+}
+
+// WindowChange informs the remote host about a terminal window dimension change to h rows and w columns.
+func (s *Session) WindowChange(h, w int) error {
+	req := ptyWindowChangeMsg{
+		Columns: uint32(w),
+		Rows:    uint32(h),
+		Width:   uint32(w * 8),
+		Height:  uint32(h * 8),
+	}
+	_, err := s.ch.SendRequest("window-change", false, Marshal(&req))
+	return err
+}
+
 // RFC 4254 Section 6.9.
 type signalMsg struct {
 	Signal string

vendor/golang.org/x/crypto/ssh/streamlocal.go

@@ -0,0 +1,115 @@
+package ssh
+
+import (
+	"errors"
+	"io"
+	"net"
+)
+
+// streamLocalChannelOpenDirectMsg is a struct used for SSH_MSG_CHANNEL_OPEN message
+// with "direct-streamlocal@openssh.com" string.
+//
+// See openssh-portable/PROTOCOL, section 2.4. connection: Unix domain socket forwarding
+// https://github.com/openssh/openssh-portable/blob/master/PROTOCOL#L235
+type streamLocalChannelOpenDirectMsg struct {
+	socketPath string
+	reserved0  string
+	reserved1  uint32
+}
+
+// forwardedStreamLocalPayload is a struct used for SSH_MSG_CHANNEL_OPEN message
+// with "forwarded-streamlocal@openssh.com" string.
+type forwardedStreamLocalPayload struct {
+	SocketPath string
+	Reserved0  string
+}
+
+// streamLocalChannelForwardMsg is a struct used for SSH2_MSG_GLOBAL_REQUEST message
+// with "streamlocal-forward@openssh.com"/"cancel-streamlocal-forward@openssh.com" string.
+type streamLocalChannelForwardMsg struct {
+	socketPath string
+}
+
+// ListenUnix is similar to ListenTCP but uses a Unix domain socket.
+func (c *Client) ListenUnix(socketPath string) (net.Listener, error) {
+	m := streamLocalChannelForwardMsg{
+		socketPath,
+	}
+	// send message
+	ok, _, err := c.SendRequest("streamlocal-forward@openssh.com", true, Marshal(&m))
+	if err != nil {
+		return nil, err
+	}
+	if !ok {
+		return nil, errors.New("ssh: streamlocal-forward@openssh.com request denied by peer")
+	}
+	ch := c.forwards.add(&net.UnixAddr{Name: socketPath, Net: "unix"})
+
+	return &unixListener{socketPath, c, ch}, nil
+}
+
+func (c *Client) dialStreamLocal(socketPath string) (Channel, error) {
+	msg := streamLocalChannelOpenDirectMsg{
+		socketPath: socketPath,
+	}
+	ch, in, err := c.OpenChannel("direct-streamlocal@openssh.com", Marshal(&msg))
+	if err != nil {
+		return nil, err
+	}
+	go DiscardRequests(in)
+	return ch, err
+}
+
+type unixListener struct {
+	socketPath string
+
+	conn *Client
+	in   <-chan forward
+}
+
+// Accept waits for and returns the next connection to the listener.
+func (l *unixListener) Accept() (net.Conn, error) {
+	s, ok := <-l.in
+	if !ok {
+		return nil, io.EOF
+	}
+	ch, incoming, err := s.newCh.Accept()
+	if err != nil {
+		return nil, err
+	}
+	go DiscardRequests(incoming)
+
+	return &chanConn{
+		Channel: ch,
+		laddr: &net.UnixAddr{
+			Name: l.socketPath,
+			Net:  "unix",
+		},
+		raddr: &net.UnixAddr{
+			Name: "@",
+			Net:  "unix",
+		},
+	}, nil
+}
+
+// Close closes the listener.
+func (l *unixListener) Close() error {
+	// this also closes the listener.
+	l.conn.forwards.remove(&net.UnixAddr{Name: l.socketPath, Net: "unix"})
+	m := streamLocalChannelForwardMsg{
+		l.socketPath,
+	}
+	ok, _, err := l.conn.SendRequest("cancel-streamlocal-forward@openssh.com", true, Marshal(&m))
+	if err == nil && !ok {
+		err = errors.New("ssh: cancel-streamlocal-forward@openssh.com failed")
+	}
+	return err
+}
+
+// Addr returns the listener's network address.
+func (l *unixListener) Addr() net.Addr {
+	return &net.UnixAddr{
+		Name: l.socketPath,
+		Net:  "unix",
+	}
+}

vendor/golang.org/x/crypto/ssh/tcpip.go

@@ -20,12 +20,20 @@ import (
 // addr. Incoming connections will be available by calling Accept on
 // the returned net.Listener. The listener must be serviced, or the
 // SSH connection may hang.
+// N must be "tcp", "tcp4", "tcp6", or "unix".
 func (c *Client) Listen(n, addr string) (net.Listener, error) {
-	laddr, err := net.ResolveTCPAddr(n, addr)
+	switch n {
-	if err != nil {
+	case "tcp", "tcp4", "tcp6":
-		return nil, err
+		laddr, err := net.ResolveTCPAddr(n, addr)
+		if err != nil {
+			return nil, err
+		}
+		return c.ListenTCP(laddr)
+	case "unix":
+		return c.ListenUnix(addr)
+	default:
+		return nil, fmt.Errorf("ssh: unsupported protocol: %s", n)
 	}
-	return c.ListenTCP(laddr)
 }
 
 // Automatic port allocation is broken with OpenSSH before 6.0. See
@@ -116,7 +124,7 @@ func (c *Client) ListenTCP(laddr *net.TCPAddr) (net.Listener, error) {
 	}
 
 	// Register this forward, using the port number we obtained.
-	ch := c.forwards.add(*laddr)
+	ch := c.forwards.add(laddr)
 
 	return &tcpListener{laddr, c, ch}, nil
 }
@@ -131,7 +139,7 @@ type forwardList struct {
 // forwardEntry represents an established mapping of a laddr on a
 // remote ssh server to a channel connected to a tcpListener.
 type forwardEntry struct {
-	laddr net.TCPAddr
+	laddr net.Addr
 	c     chan forward
 }
 
@@ -139,16 +147,16 @@ type forwardEntry struct {
 // arguments to add/remove/lookup should be address as specified in
 // the original forward-request.
 type forward struct {
-	newCh NewChannel   // the ssh client channel underlying this forward
+	newCh NewChannel // the ssh client channel underlying this forward
-	raddr *net.TCPAddr // the raddr of the incoming connection
+	raddr net.Addr   // the raddr of the incoming connection
 }
 
-func (l *forwardList) add(addr net.TCPAddr) chan forward {
+func (l *forwardList) add(addr net.Addr) chan forward {
 	l.Lock()
 	defer l.Unlock()
 	f := forwardEntry{
-		addr,
+		laddr: addr,
-		make(chan forward, 1),
+		c:     make(chan forward, 1),
 	}
 	l.entries = append(l.entries, f)
 	return f.c
@@ -176,44 +184,69 @@ func parseTCPAddr(addr string, port uint32) (*net.TCPAddr, error) {
 
 func (l *forwardList) handleChannels(in <-chan NewChannel) {
 	for ch := range in {
-		var payload forwardedTCPPayload
+		var (
-		if err := Unmarshal(ch.ExtraData(), &payload); err != nil {
+			laddr net.Addr
-			ch.Reject(ConnectionFailed, "could not parse forwarded-tcpip payload: "+err.Error())
+			raddr net.Addr
-			continue
+			err   error
-		}
+		)
+		switch channelType := ch.ChannelType(); channelType {
+		case "forwarded-tcpip":
+			var payload forwardedTCPPayload
+			if err = Unmarshal(ch.ExtraData(), &payload); err != nil {
+				ch.Reject(ConnectionFailed, "could not parse forwarded-tcpip payload: "+err.Error())
+				continue
+			}
 
-		// RFC 4254 section 7.2 specifies that incoming
+			// RFC 4254 section 7.2 specifies that incoming
-		// addresses should list the address, in string
+			// addresses should list the address, in string
-		// format. It is implied that this should be an IP
+			// format. It is implied that this should be an IP
-		// address, as it would be impossible to connect to it
+			// address, as it would be impossible to connect to it
-		// otherwise.
+			// otherwise.
-		laddr, err := parseTCPAddr(payload.Addr, payload.Port)
+			laddr, err = parseTCPAddr(payload.Addr, payload.Port)
-		if err != nil {
+			if err != nil {
-			ch.Reject(ConnectionFailed, err.Error())
+				ch.Reject(ConnectionFailed, err.Error())
-			continue
+				continue
-		}
+			}
-		raddr, err := parseTCPAddr(payload.OriginAddr, payload.OriginPort)
+			raddr, err = parseTCPAddr(payload.OriginAddr, payload.OriginPort)
-		if err != nil {
+			if err != nil {
-			ch.Reject(ConnectionFailed, err.Error())
+				ch.Reject(ConnectionFailed, err.Error())
-			continue
+				continue
-		}
+			}
 
-		if ok := l.forward(*laddr, *raddr, ch); !ok {
+		case "forwarded-streamlocal@openssh.com":
+			var payload forwardedStreamLocalPayload
+			if err = Unmarshal(ch.ExtraData(), &payload); err != nil {
+				ch.Reject(ConnectionFailed, "could not parse forwarded-streamlocal@openssh.com payload: "+err.Error())
+				continue
+			}
+			laddr = &net.UnixAddr{
+				Name: payload.SocketPath,
+				Net:  "unix",
+			}
+			raddr = &net.UnixAddr{
+				Name: "@",
+				Net:  "unix",
+			}
+		default:
+			panic(fmt.Errorf("ssh: unknown channel type %s", channelType))
+		}
+		if ok := l.forward(laddr, raddr, ch); !ok {
 			// Section 7.2, implementations MUST reject spurious incoming
 			// connections.
 			ch.Reject(Prohibited, "no forward for address")
 			continue
 		}
+
 	}
 }
 
 // remove removes the forward entry, and the channel feeding its
 // listener.
-func (l *forwardList) remove(addr net.TCPAddr) {
+func (l *forwardList) remove(addr net.Addr) {
 	l.Lock()
 	defer l.Unlock()
 	for i, f := range l.entries {
-		if addr.IP.Equal(f.laddr.IP) && addr.Port == f.laddr.Port {
+		if addr.Network() == f.laddr.Network() && addr.String() == f.laddr.String() {
 			l.entries = append(l.entries[:i], l.entries[i+1:]...)
 			close(f.c)
 			return
@@ -231,12 +264,12 @@ func (l *forwardList) closeAll() {
 	l.entries = nil
 }
 
-func (l *forwardList) forward(laddr, raddr net.TCPAddr, ch NewChannel) bool {
+func (l *forwardList) forward(laddr, raddr net.Addr, ch NewChannel) bool {
 	l.Lock()
 	defer l.Unlock()
 	for _, f := range l.entries {
-		if laddr.IP.Equal(f.laddr.IP) && laddr.Port == f.laddr.Port {
+		if laddr.Network() == f.laddr.Network() && laddr.String() == f.laddr.String() {
-			f.c <- forward{ch, &raddr}
+			f.c <- forward{newCh: ch, raddr: raddr}
 			return true
 		}
 	}
@@ -262,7 +295,7 @@ func (l *tcpListener) Accept() (net.Conn, error) {
 	}
 	go DiscardRequests(incoming)
 
-	return &tcpChanConn{
+	return &chanConn{
 		Channel: ch,
 		laddr:   l.laddr,
 		raddr:   s.raddr,
@@ -277,7 +310,7 @@ func (l *tcpListener) Close() error {
 	}
 
 	// this also closes the listener.
-	l.conn.forwards.remove(*l.laddr)
+	l.conn.forwards.remove(l.laddr)
 	ok, _, err := l.conn.SendRequest("cancel-tcpip-forward", true, Marshal(&m))
 	if err == nil && !ok {
 		err = errors.New("ssh: cancel-tcpip-forward failed")
@@ -293,29 +326,52 @@ func (l *tcpListener) Addr() net.Addr {
 // Dial initiates a connection to the addr from the remote host.
 // The resulting connection has a zero LocalAddr() and RemoteAddr().
 func (c *Client) Dial(n, addr string) (net.Conn, error) {
-	// Parse the address into host and numeric port.
+	var ch Channel
-	host, portString, err := net.SplitHostPort(addr)
+	switch n {
-	if err != nil {
+	case "tcp", "tcp4", "tcp6":
-		return nil, err
+		// Parse the address into host and numeric port.
+		host, portString, err := net.SplitHostPort(addr)
+		if err != nil {
+			return nil, err
+		}
+		port, err := strconv.ParseUint(portString, 10, 16)
+		if err != nil {
+			return nil, err
+		}
+		ch, err = c.dial(net.IPv4zero.String(), 0, host, int(port))
+		if err != nil {
+			return nil, err
+		}
+		// Use a zero address for local and remote address.
+		zeroAddr := &net.TCPAddr{
+			IP:   net.IPv4zero,
+			Port: 0,
+		}
+		return &chanConn{
+			Channel: ch,
+			laddr:   zeroAddr,
+			raddr:   zeroAddr,
+		}, nil
+	case "unix":
+		var err error
+		ch, err = c.dialStreamLocal(addr)
+		if err != nil {
+			return nil, err
+		}
+		return &chanConn{
+			Channel: ch,
+			laddr: &net.UnixAddr{
+				Name: "@",
+				Net:  "unix",
+			},
+			raddr: &net.UnixAddr{
+				Name: addr,
+				Net:  "unix",
+			},
+		}, nil
+	default:
+		return nil, fmt.Errorf("ssh: unsupported protocol: %s", n)
 	}
-	port, err := strconv.ParseUint(portString, 10, 16)
-	if err != nil {
-		return nil, err
-	}
-	// Use a zero address for local and remote address.
-	zeroAddr := &net.TCPAddr{
-		IP:   net.IPv4zero,
-		Port: 0,
-	}
-	ch, err := c.dial(net.IPv4zero.String(), 0, host, int(port))
-	if err != nil {
-		return nil, err
-	}
-	return &tcpChanConn{
-		Channel: ch,
-		laddr:   zeroAddr,
-		raddr:   zeroAddr,
-	}, nil
 }
 
 // DialTCP connects to the remote address raddr on the network net,
@@ -332,7 +388,7 @@ func (c *Client) DialTCP(n string, laddr, raddr *net.TCPAddr) (net.Conn, error)
 	if err != nil {
 		return nil, err
 	}
-	return &tcpChanConn{
+	return &chanConn{
 		Channel: ch,
 		laddr:   laddr,
 		raddr:   raddr,
@@ -366,26 +422,26 @@ type tcpChan struct {
 	Channel // the backing channel
 }
 
-// tcpChanConn fulfills the net.Conn interface without
+// chanConn fulfills the net.Conn interface without
 // the tcpChan having to hold laddr or raddr directly.
-type tcpChanConn struct {
+type chanConn struct {
 	Channel
 	laddr, raddr net.Addr
 }
 
 // LocalAddr returns the local network address.
-func (t *tcpChanConn) LocalAddr() net.Addr {
+func (t *chanConn) LocalAddr() net.Addr {
 	return t.laddr
 }
 
 // RemoteAddr returns the remote network address.
-func (t *tcpChanConn) RemoteAddr() net.Addr {
+func (t *chanConn) RemoteAddr() net.Addr {
 	return t.raddr
 }
 
 // SetDeadline sets the read and write deadlines associated
 // with the connection.
-func (t *tcpChanConn) SetDeadline(deadline time.Time) error {
+func (t *chanConn) SetDeadline(deadline time.Time) error {
 	if err := t.SetReadDeadline(deadline); err != nil {
 		return err
 	}
@@ -396,12 +452,14 @@ func (t *tcpChanConn) SetDeadline(deadline time.Time) error {
 // A zero value for t means Read will not time out.
 // After the deadline, the error from Read will implement net.Error
 // with Timeout() == true.
-func (t *tcpChanConn) SetReadDeadline(deadline time.Time) error {
+func (t *chanConn) SetReadDeadline(deadline time.Time) error {
+	// for compatibility with previous version,
+	// the error message contains "tcpChan"
 	return errors.New("ssh: tcpChan: deadline not supported")
 }
 
 // SetWriteDeadline exists to satisfy the net.Conn interface
 // but is not implemented by this type.  It always returns an error.
-func (t *tcpChanConn) SetWriteDeadline(deadline time.Time) error {
+func (t *chanConn) SetWriteDeadline(deadline time.Time) error {
 	return errors.New("ssh: tcpChan: deadline not supported")
 }

vendor/golang.org/x/crypto/ssh/transport.go

@@ -8,8 +8,13 @@ import (
 	"bufio"
 	"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 +27,9 @@ 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 +45,7 @@ type transport struct {
 	bufReader *bufio.Reader
 	bufWriter *bufio.Writer
 	rand      io.Reader
-
+	isClient  bool
 	io.Closer
 }
 
@@ -84,9 +91,38 @@ func (t *transport) prepareKeyChange(algs *algorithms, kexResult *kexResult) err
 	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) {
+func (t *transport) readPacket() (p []byte, err error) {
-	return t.reader.readPacket(t.bufReader)
+	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) {
@@ -129,6 +165,9 @@ 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 +208,8 @@ 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
@@ -213,7 +254,7 @@ func newPacketCipher(d direction, algs directionAlgorithms, kex *kexResult) (pac
 	iv, key, macKey := generateKeys(d, algs, kex)
 
 	if algs.Cipher == gcmCipherID {
-		return newGCMCipher(iv, key, macKey)
+		return newGCMCipher(iv, key)
 	}
 
 	if algs.Cipher == aes128cbcID {
@@ -226,6 +267,7 @@ func newPacketCipher(d direction, algs directionAlgorithms, kex *kexResult) (pac
 
 	c := &streamPacketCipher{
 		mac: macModes[algs.MAC].new(macKey),
+		etm: macModes[algs.MAC].etm,
 	}
 	c.macResult = make([]byte, c.mac.Size())
 

vendor/vendor.json

@@ -1279,40 +1279,40 @@
 			"revisionTime": "2016-09-14T08:04:27Z"
 		},
 		{
-			"checksumSHA1": "dwOedwBJ1EIK9+S3t108Bx054Y8=",
+			"checksumSHA1": "IQkUIOnvlf0tYloFx9mLaXSvXWQ=",
 			"path": "golang.org/x/crypto/curve25519",
-			"revision": "9477e0b78b9ac3d0b03822fd95422e2fe07627cd",
+			"revision": "9f005a07e0d31d45e6656d241bb5c0f2efd4bc94",
-			"revisionTime": "2016-10-31T15:37:30Z"
+			"revisionTime": "2017-09-21T17:41:56Z"
 		},
 		{
-			"checksumSHA1": "wGb//LjBPNxYHqk+dcLo7BjPXK8=",
+			"checksumSHA1": "1hwn8cgg4EVXhCpJIqmMbzqnUo0=",
 			"path": "golang.org/x/crypto/ed25519",
-			"revision": "9477e0b78b9ac3d0b03822fd95422e2fe07627cd",
+			"revision": "9f005a07e0d31d45e6656d241bb5c0f2efd4bc94",
-			"revisionTime": "2016-10-31T15:37:30Z"
+			"revisionTime": "2017-09-21T17:41:56Z"
 		},
 		{
 			"checksumSHA1": "LXFcVx8I587SnWmKycSDEq9yvK8=",
 			"path": "golang.org/x/crypto/ed25519/internal/edwards25519",
-			"revision": "9477e0b78b9ac3d0b03822fd95422e2fe07627cd",
+			"revision": "9f005a07e0d31d45e6656d241bb5c0f2efd4bc94",
-			"revisionTime": "2016-10-31T15:37:30Z"
+			"revisionTime": "2017-09-21T17:41:56Z"
 		},
 		{
 			"checksumSHA1": "MCeXr2RNeiG1XG6V+er1OR0qyeo=",
 			"path": "golang.org/x/crypto/md4",
-			"revision": "ede567c8e044a5913dad1d1af3696d9da953104c",
+			"revision": "9f005a07e0d31d45e6656d241bb5c0f2efd4bc94",
-			"revisionTime": "2016-11-04T19:41:44Z"
+			"revisionTime": "2017-09-21T17:41:56Z"
 		},
 		{
 			"checksumSHA1": "1MGpGDQqnUoRpv7VEcQrXOBydXE=",
 			"path": "golang.org/x/crypto/pbkdf2",
-			"revision": "8e06e8ddd9629eb88639aba897641bff8031f1d3",
+			"revision": "9f005a07e0d31d45e6656d241bb5c0f2efd4bc94",
-			"revisionTime": "2016-09-10T18:59:01Z"
+			"revisionTime": "2017-09-21T17:41:56Z"
 		},
 		{
-			"checksumSHA1": "LlElMHeTC34ng8eHzjvtUhAgrr8=",
+			"checksumSHA1": "YXeyyvak2xbvsqj5MBHMzyG+22M=",
 			"path": "golang.org/x/crypto/ssh",
-			"revision": "9477e0b78b9ac3d0b03822fd95422e2fe07627cd",
+			"revision": "9f005a07e0d31d45e6656d241bb5c0f2efd4bc94",
-			"revisionTime": "2016-10-31T15:37:30Z"
+			"revisionTime": "2017-09-21T17:41:56Z"
 		},
 		{
 			"checksumSHA1": "9jjO5GjLa0XF/nfWihF02RoH4qc=",