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

* Update golang x/crypto dependencies (#2923)

* Fix govendor for x/crupto curve25519 (#2925)
This commit is contained in:
Lauris BH 2017-11-21 06:25:53 +02:00 committed by GitHub
parent c31e8777b7
commit be41955407
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
31 changed files with 1341 additions and 492 deletions

8
vendor/golang.org/x/crypto/curve25519/const_amd64.h generated vendored Normal file
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@ -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

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@ -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
GLOBL ·REDMASK51(SB), 8, $8
// These constants cannot be encoded in non-MOVQ immediates.
// We access them directly from memory instead.
DATA ·_121666_213(SB)/8, $996687872
GLOBL ·_121666_213(SB), 8, $8

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@ -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
MOVQ 0(DI),SI
MOVQ 80(DI),DX
MOVQ 8(DI),CX
MOVQ 88(DI),R8
MOVQ SI,R9
CMOVQEQ DX,SI
CMOVQEQ R9,DX
MOVQ CX,R9
CMOVQEQ R8,CX
CMOVQEQ R9,R8
MOVQ SI,0(DI)
MOVQ DX,80(DI)
MOVQ CX,8(DI)
MOVQ R8,88(DI)
MOVQ 16(DI),SI
MOVQ 96(DI),DX
MOVQ 24(DI),CX
MOVQ 104(DI),R8
MOVQ SI,R9
CMOVQEQ DX,SI
CMOVQEQ R9,DX
MOVQ CX,R9
CMOVQEQ R8,CX
CMOVQEQ R9,R8
MOVQ SI,16(DI)
MOVQ DX,96(DI)
MOVQ CX,24(DI)
MOVQ R8,104(DI)
MOVQ 32(DI),SI
MOVQ 112(DI),DX
MOVQ 40(DI),CX
MOVQ 120(DI),R8
MOVQ SI,R9
CMOVQEQ DX,SI
CMOVQEQ R9,DX
MOVQ CX,R9
CMOVQEQ R8,CX
CMOVQEQ R9,R8
MOVQ SI,32(DI)
MOVQ DX,112(DI)
MOVQ CX,40(DI)
MOVQ R8,120(DI)
MOVQ 48(DI),SI
MOVQ 128(DI),DX
MOVQ 56(DI),CX
MOVQ 136(DI),R8
MOVQ SI,R9
CMOVQEQ DX,SI
CMOVQEQ R9,DX
MOVQ CX,R9
CMOVQEQ R8,CX
CMOVQEQ R9,R8
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
SUBQ $1, SI
NOTQ SI
MOVQ SI, X15
PSHUFD $0x44, X15, X15
MOVOU 0(DI), X0
MOVOU 16(DI), X2
MOVOU 32(DI), X4
MOVOU 48(DI), X6
MOVOU 64(DI), X8
MOVOU 80(DI), X1
MOVOU 96(DI), X3
MOVOU 112(DI), X5
MOVOU 128(DI), X7
MOVOU 144(DI), X9
MOVO X1, X10
MOVO X3, X11
MOVO X5, X12
MOVO X7, X13
MOVO X9, X14
PXOR X0, X10
PXOR X2, X11
PXOR X4, X12
PXOR X6, X13
PXOR X8, X14
PAND X15, X10
PAND X15, X11
PAND X15, X12
PAND X15, X13
PAND X15, X14
PXOR X10, X0
PXOR X10, X1
PXOR X11, X2
PXOR X11, X3
PXOR X12, X4
PXOR X12, X5
PXOR X13, X6
PXOR X13, X7
PXOR X14, X8
PXOR X14, X9
MOVOU X0, 0(DI)
MOVOU X2, 16(DI)
MOVOU X4, 32(DI)
MOVOU X6, 48(DI)
MOVOU X8, 64(DI)
MOVOU X1, 80(DI)
MOVOU X3, 96(DI)
MOVOU X5, 112(DI)
MOVOU X7, 128(DI)
MOVOU X9, 144(DI)
RET

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@ -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]
}
for i := range g {
g[i] ^= x[i]
t := b & (f[i] ^ g[i])
f[i] ^= t
g[i] ^= t
}
}
@ -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
r = int64(in[0])
r |= int64(in[1]) << 8
r |= int64(in[2]) << 16
r |= int64(in[3]) << 24
return r
return int64(binary.LittleEndian.Uint32(in))
}
func feFromBytes(dst *fieldElement, src *[32]byte) {

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@ -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.

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@ -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

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@ -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

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@ -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

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@ -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

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@ -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[:])
}

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@ -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.
func (b *buffer) eof() error {
// the data has been consumed will receive io.EOF.
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

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@ -251,10 +251,18 @@ type CertChecker struct {
// for user certificates.
SupportedCriticalOptions []string
// IsAuthority should return true if the key is recognized as
// an authority. This allows for certificates to be signed by other
// certificates.
IsAuthority func(auth PublicKey) bool
// IsUserAuthority should return true if the key is recognized as an
// authority for the given user certificate. This allows for
// certificates to be signed by other certificates. This must be set
// 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

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

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@ -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)
}

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@ -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
// handshake to validate the server's host key. A nil HostKeyCallback
// implies that all host keys are accepted.
HostKeyCallback func(hostname string, remote net.Addr, key PublicKey) error
// HostKeyCallback is called during the cryptographic
// handshake to validate the server's host key. The client
// configuration must supply this callback for the connection
// 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
}
}

View File

@ -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
// enquiry to test if each key is acceptable to the remote. The second
// stage attempts to authenticate with the valid keys obtained in the
// first stage.
// Authentication is performed by sending an enquiry to test if a key is
// acceptable to the remote. If the key is acceptable, the client will
// attempt to authenticate with the valid key. If not the client will repeat
// 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 {
pub := signer.PublicKey()
for _, signer := range signers {
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

View File

@ -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.
c.RekeyThreshold = 1 << 30
}
if c.RekeyThreshold < minRekeyThreshold {
// cipher specific default
} else 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
}
}

View File

@ -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

View File

@ -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"

View File

@ -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
mu sync.Mutex
cond *sync.Cond
sentInitPacket []byte
sentInitMsg *kexInitMsg
writtenSinceKex uint64
writeError error
// Algorithms agreed in the last key exchange.
algorithms *algorithms
readPacketsLeft uint32
readBytesLeft int64
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),
config: config,
incoming: make(chan []byte, chanSize),
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.
t.mu.Lock()
defer t.mu.Unlock()
if t.writeError == nil {
t.writeError = t.readError
}
t.cond.Broadcast()
// Stop writers too.
t.recordWriteError(t.readError)
// Unblock the writer should it wait for this.
close(t.startKex)
// Don't close t.requestKex; it's also written to from writePacket.
}
func (t *handshakeTransport) readOnePacket() ([]byte, error) {
if t.readSinceKex > t.config.RekeyThreshold {
if err := t.requestKeyChange(); err != nil {
return nil, err
func (t *handshakeTransport) pushPacket(p []byte) error {
if debugHandshake {
t.printPacket(p, true)
}
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 debugHandshake {
if p[0] == msgChannelData || p[0] == msgChannelExtendedData {
log.Printf("%s got data (packet %d bytes)", t.id(), len(p))
} else {
msg, err := decode(p)
log.Printf("%s got %T %v (%v)", t.id(), msg, msg, err)
}
if t.readPacketsLeft > 0 {
t.readPacketsLeft--
} else {
t.requestKeyExchange()
}
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)
if err != nil {
// drop connection
t.conn.Close()
t.writeError = err
kex := pendingKex{
done: make(chan error, 1),
otherInit: p,
}
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
// connection, or a subsequent one.
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
// sendKexInit sends a key change message.
func (t *handshakeTransport) sendKexInit() error {
t.mu.Lock()
// If this is the initial key change, but we already have a sessionID,
// 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.
defer t.mu.Unlock()
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 {
return nil, nil, err
if err := t.pushPacket(packetCopy); err != nil {
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) enterKeyExchangeLocked(otherInitPacket []byte) error {
func (t *handshakeTransport) enterKeyExchange(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
serverInit = otherInit
clientInit, serverInit = serverInit, clientInit
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)
if err != nil {
return nil, err
}
err = t.hostKeyCallback(t.dialAddress, t.remoteAddr, hostKey)
if err != nil {
return nil, err
}
return result, nil

View File

@ -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),
p: p,
g: new(big.Int).SetInt64(2),
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),
p: p,
g: new(big.Int).SetInt64(2),
p: p,
pMinus1: new(big.Int).Sub(p, bigOne),
}

View File

@ -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{
P: w.P,
Q: w.Q,
G: w.G,
},
Y: w.Y,
Parameters: param,
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
// Signer instance. ECDSA keys must use P-256, P-384 or P-521.
// *ecdsa.PrivateKey or any other crypto.Signer and returns a
// 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
Priv []byte
Comment string
Pad []byte `ssh:"rest"`
Rest []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
if pk1.Keytype != KeyAlgoED25519 {
// we only handle ed25519 and rsa keys currently
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 {
return nil, errors.New("ssh: padding not as expected")
}
}
if len(pk1.Priv) != ed25519.PrivateKeySize {
return nil, errors.New("ssh: private key unexpected length")
}
pk := ed25519.PrivateKey(make([]byte, ed25519.PrivateKeySize))
copy(pk, pk1.Priv)
return &pk, nil
}
// FingerprintLegacyMD5 returns the user presentation of the key's
// fingerprint as described by RFC 4716 section 4.
func FingerprintLegacyMD5(pubKey PublicKey) string {
md5sum := md5.Sum(pubKey.Marshal())
hexarray := make([]string, len(md5sum))
for i, c := range md5sum {
hexarray[i] = hex.EncodeToString([]byte{c})
}
return strings.Join(hexarray, ":")
}
// 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
}

View File

@ -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)}
}},
}

View File

@ -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

View File

@ -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 {

View File

@ -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
// user. Permissions, except for "source-address", must be enforced in
// the server application layer, after successful authentication. The
// Permissions are passed on in ServerConn so a server implementation
// can honor them.
// specific to a user or a specific authentication method for a user.
// The Permissions value for a successful authentication attempt is
// available in ServerConn, so it can be used to pass information from
// the user-authentication phase to the application layer.
type Permissions struct {
// Critical options restrict default permissions. Common
// restrictions are "source-address" and "force-command". If
// the server cannot enforce the restriction, or does not
// recognize it, the user should not authenticate.
// CriticalOptions indicate restrictions to the default
// permissions, and are typically used in conjunction with
// user certificates. The standard for SSH certificates
// 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
// "permit-agent-forwarding", "permit-X11-forwarding". Lack of
// support for an extension does not preclude authenticating a
// user.
// offer on authenticated connections. Lack of support for an
// extension does not preclude authenticating a user. Common
// extensions are "permit-agent-forwarding",
// "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
// key authentication. It must return true if the given public key is
// valid for the given user. For example, see CertChecker.Authenticate.
// PublicKeyCallback, if non-nil, is called when a client
// offers a public key for authentication. It must return a nil error
// 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 {
if bytes.Equal(allowedIP, tcpAddr.IP) {
return nil
}
} else {
_, ipNet, err := net.ParseCIDR(sourceAddr)
if err != nil {
return fmt.Errorf("ssh: error parsing source-address restriction %q: %v", sourceAddr, err)
}
for _, sourceAddr := range strings.Split(sourceAddrs, ",") {
if allowedIP := net.ParseIP(sourceAddr); allowedIP != nil {
if allowedIP.Equal(tcpAddr.IP) {
return nil
}
} else {
_, ipNet, err := net.ParseCIDR(sourceAddr)
if err != nil {
return fmt.Errorf("ssh: error parsing source-address restriction %q: %v", sourceAddr, err)
}
if ipNet.Contains(tcpAddr.IP) {
return nil
if ipNet.Contains(tcpAddr.IP) {
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

View File

@ -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

115
vendor/golang.org/x/crypto/ssh/streamlocal.go generated vendored Normal file
View File

@ -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",
}
}

View File

@ -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)
if err != nil {
return nil, err
switch n {
case "tcp", "tcp4", "tcp6":
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
raddr *net.TCPAddr // the raddr of the incoming connection
newCh NewChannel // the ssh client channel underlying this forward
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,
make(chan forward, 1),
laddr: addr,
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
if err := Unmarshal(ch.ExtraData(), &payload); err != nil {
ch.Reject(ConnectionFailed, "could not parse forwarded-tcpip payload: "+err.Error())
continue
}
var (
laddr net.Addr
raddr net.Addr
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
// addresses should list the address, in string
// format. It is implied that this should be an IP
// address, as it would be impossible to connect to it
// otherwise.
laddr, err := parseTCPAddr(payload.Addr, payload.Port)
if err != nil {
ch.Reject(ConnectionFailed, err.Error())
continue
}
raddr, err := parseTCPAddr(payload.OriginAddr, payload.OriginPort)
if err != nil {
ch.Reject(ConnectionFailed, err.Error())
continue
}
// RFC 4254 section 7.2 specifies that incoming
// addresses should list the address, in string
// format. It is implied that this should be an IP
// address, as it would be impossible to connect to it
// otherwise.
laddr, err = parseTCPAddr(payload.Addr, payload.Port)
if err != nil {
ch.Reject(ConnectionFailed, err.Error())
continue
}
raddr, err = parseTCPAddr(payload.OriginAddr, payload.OriginPort)
if err != nil {
ch.Reject(ConnectionFailed, err.Error())
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 {
f.c <- forward{ch, &raddr}
if laddr.Network() == f.laddr.Network() && laddr.String() == f.laddr.String() {
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.
host, portString, err := net.SplitHostPort(addr)
if err != nil {
return nil, err
var ch Channel
switch n {
case "tcp", "tcp4", "tcp6":
// 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")
}

View File

@ -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) {
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) {
@ -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())

30
vendor/vendor.json vendored
View File

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