TUN-6158: Update golang.org/x/crypto

This commit is contained in:
Nuno Diegues 2022-05-02 09:34:39 +01:00
parent 3254d08173
commit e8fe34773c
27 changed files with 572 additions and 3769 deletions

2
go.mod
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@ -35,7 +35,7 @@ require (
go.opentelemetry.io/otel/trace v1.6.3
go.opentelemetry.io/proto/otlp v0.15.0
go.uber.org/automaxprocs v1.4.0
golang.org/x/crypto v0.0.0-20210921155107-089bfa567519
golang.org/x/crypto v0.0.0-20220427172511-eb4f295cb31f
golang.org/x/net v0.0.0-20220114011407-0dd24b26b47d
golang.org/x/sync v0.0.0-20210220032951-036812b2e83c
golang.org/x/sys v0.0.0-20220114195835-da31bd327af9

4
go.sum
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@ -636,8 +636,9 @@ golang.org/x/crypto v0.0.0-20201002170205-7f63de1d35b0/go.mod h1:LzIPMQfyMNhhGPh
golang.org/x/crypto v0.0.0-20201112155050-0c6587e931a9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
golang.org/x/crypto v0.0.0-20210817164053-32db794688a5/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
golang.org/x/crypto v0.0.0-20210920023735-84f357641f63/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
golang.org/x/crypto v0.0.0-20210921155107-089bfa567519 h1:7I4JAnoQBe7ZtJcBaYHi5UtiO8tQHbUSXxL+pnGRANg=
golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
golang.org/x/crypto v0.0.0-20220427172511-eb4f295cb31f h1:OeJjE6G4dgCY4PIXvIRQbE8+RX+uXZyGhUy/ksMGJoc=
golang.org/x/crypto v0.0.0-20220427172511-eb4f295cb31f/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
golang.org/x/exp v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
golang.org/x/exp v0.0.0-20190510132918-efd6b22b2522/go.mod h1:ZjyILWgesfNpC6sMxTJOJm9Kp84zZh5NQWvqDGG3Qr8=
@ -723,6 +724,7 @@ golang.org/x/net v0.0.0-20210503060351-7fd8e65b6420/go.mod h1:9nx3DQGgdP8bBQD5qx
golang.org/x/net v0.0.0-20210525063256-abc453219eb5/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
golang.org/x/net v0.0.0-20210726213435-c6fcb2dbf985/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
golang.org/x/net v0.0.0-20210917221730-978cfadd31cf/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
golang.org/x/net v0.0.0-20211209124913-491a49abca63/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
golang.org/x/net v0.0.0-20211216030914-fe4d6282115f/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
golang.org/x/net v0.0.0-20220114011407-0dd24b26b47d h1:1n1fc535VhN8SYtD4cDUyNlfpAF2ROMM9+11equK3hs=

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@ -15,6 +15,7 @@ const bufSize = 256
// xorKeyStreamVX is an assembly implementation of XORKeyStream. It must only
// be called when the vector facility is available. Implementation in asm_s390x.s.
//
//go:noescape
func xorKeyStreamVX(dst, src []byte, key *[8]uint32, nonce *[3]uint32, counter *uint32)

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@ -407,7 +407,12 @@ func (s *String) ReadASN1Enum(out *int) bool {
func (s *String) readBase128Int(out *int) bool {
ret := 0
for i := 0; len(*s) > 0; i++ {
if i == 4 {
if i == 5 {
return false
}
// Avoid overflowing int on a 32-bit platform.
// We don't want different behavior based on the architecture.
if ret >= 1<<(31-7) {
return false
}
ret <<= 7

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@ -1,13 +1,16 @@
// Code generated by command: go run fe_amd64_asm.go -out ../fe_amd64.s -stubs ../fe_amd64.go -pkg field. DO NOT EDIT.
//go:build amd64 && gc && !purego
// +build amd64,gc,!purego
package field
// feMul sets out = a * b. It works like feMulGeneric.
//
//go:noescape
func feMul(out *Element, a *Element, b *Element)
// feSquare sets out = a * a. It works like feSquareGeneric.
//
//go:noescape
func feSquare(out *Element, a *Element)

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@ -1,13 +1,7 @@
// Copyright 2016 The Go Authors. All rights reserved.
// Copyright 2019 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.
// In Go 1.13, the ed25519 package was promoted to the standard library as
// crypto/ed25519, and this package became a wrapper for the standard library one.
//
//go:build !go1.13
// +build !go1.13
// Package ed25519 implements the Ed25519 signature algorithm. See
// https://ed25519.cr.yp.to/.
//
@ -16,21 +10,15 @@
// representation includes a public key suffix to make multiple signing
// operations with the same key more efficient. This package refers to the RFC
// 8032 private key as the “seed”.
//
// Beginning with Go 1.13, the functionality of this package was moved to the
// standard library as crypto/ed25519. This package only acts as a compatibility
// wrapper.
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"
"errors"
"crypto/ed25519"
"io"
"strconv"
"golang.org/x/crypto/ed25519/internal/edwards25519"
)
const (
@ -45,57 +33,21 @@ const (
)
// PublicKey is the type of Ed25519 public keys.
type PublicKey []byte
//
// This type is an alias for crypto/ed25519's PublicKey type.
// See the crypto/ed25519 package for the methods on this type.
type PublicKey = ed25519.PublicKey
// PrivateKey is the type of Ed25519 private keys. It implements crypto.Signer.
type PrivateKey []byte
// Public returns the PublicKey corresponding to priv.
func (priv PrivateKey) Public() crypto.PublicKey {
publicKey := make([]byte, PublicKeySize)
copy(publicKey, priv[32:])
return PublicKey(publicKey)
}
// Seed returns the private key seed corresponding to priv. It is provided for
// interoperability with RFC 8032. RFC 8032's private keys correspond to seeds
// in this package.
func (priv PrivateKey) Seed() []byte {
seed := make([]byte, SeedSize)
copy(seed, priv[:32])
return seed
}
// Sign signs the given message with priv.
// Ed25519 performs two passes over messages to be signed and therefore cannot
// handle pre-hashed messages. Thus opts.HashFunc() must return zero to
// indicate the message hasn't been hashed. This can be achieved by passing
// crypto.Hash(0) as the value for opts.
func (priv PrivateKey) Sign(rand io.Reader, message []byte, opts crypto.SignerOpts) (signature []byte, err error) {
if opts.HashFunc() != crypto.Hash(0) {
return nil, errors.New("ed25519: cannot sign hashed message")
}
return Sign(priv, message), nil
}
//
// This type is an alias for crypto/ed25519's PrivateKey type.
// See the crypto/ed25519 package for the methods on this type.
type PrivateKey = ed25519.PrivateKey
// GenerateKey generates a public/private key pair using entropy from rand.
// If rand is nil, crypto/rand.Reader will be used.
func GenerateKey(rand io.Reader) (PublicKey, PrivateKey, error) {
if rand == nil {
rand = cryptorand.Reader
}
seed := make([]byte, SeedSize)
if _, err := io.ReadFull(rand, seed); err != nil {
return nil, nil, err
}
privateKey := NewKeyFromSeed(seed)
publicKey := make([]byte, PublicKeySize)
copy(publicKey, privateKey[32:])
return publicKey, privateKey, nil
return ed25519.GenerateKey(rand)
}
// NewKeyFromSeed calculates a private key from a seed. It will panic if
@ -103,121 +55,17 @@ func GenerateKey(rand io.Reader) (PublicKey, PrivateKey, error) {
// with RFC 8032. RFC 8032's private keys correspond to seeds in this
// package.
func NewKeyFromSeed(seed []byte) PrivateKey {
if l := len(seed); l != SeedSize {
panic("ed25519: bad seed length: " + strconv.Itoa(l))
}
digest := sha512.Sum512(seed)
digest[0] &= 248
digest[31] &= 127
digest[31] |= 64
var A edwards25519.ExtendedGroupElement
var hBytes [32]byte
copy(hBytes[:], digest[:])
edwards25519.GeScalarMultBase(&A, &hBytes)
var publicKeyBytes [32]byte
A.ToBytes(&publicKeyBytes)
privateKey := make([]byte, PrivateKeySize)
copy(privateKey, seed)
copy(privateKey[32:], publicKeyBytes[:])
return privateKey
return ed25519.NewKeyFromSeed(seed)
}
// Sign signs the message with privateKey and returns a signature. It will
// panic if len(privateKey) is not PrivateKeySize.
func Sign(privateKey PrivateKey, message []byte) []byte {
if l := len(privateKey); l != PrivateKeySize {
panic("ed25519: bad private key length: " + strconv.Itoa(l))
}
h := sha512.New()
h.Write(privateKey[:32])
var digest1, messageDigest, hramDigest [64]byte
var expandedSecretKey [32]byte
h.Sum(digest1[:0])
copy(expandedSecretKey[:], digest1[:])
expandedSecretKey[0] &= 248
expandedSecretKey[31] &= 63
expandedSecretKey[31] |= 64
h.Reset()
h.Write(digest1[32:])
h.Write(message)
h.Sum(messageDigest[:0])
var messageDigestReduced [32]byte
edwards25519.ScReduce(&messageDigestReduced, &messageDigest)
var R edwards25519.ExtendedGroupElement
edwards25519.GeScalarMultBase(&R, &messageDigestReduced)
var encodedR [32]byte
R.ToBytes(&encodedR)
h.Reset()
h.Write(encodedR[:])
h.Write(privateKey[32:])
h.Write(message)
h.Sum(hramDigest[:0])
var hramDigestReduced [32]byte
edwards25519.ScReduce(&hramDigestReduced, &hramDigest)
var s [32]byte
edwards25519.ScMulAdd(&s, &hramDigestReduced, &expandedSecretKey, &messageDigestReduced)
signature := make([]byte, SignatureSize)
copy(signature[:], encodedR[:])
copy(signature[32:], s[:])
return signature
return ed25519.Sign(privateKey, message)
}
// Verify reports whether sig is a valid signature of message by publicKey. It
// will panic if len(publicKey) is not PublicKeySize.
func Verify(publicKey PublicKey, message, sig []byte) bool {
if l := len(publicKey); l != PublicKeySize {
panic("ed25519: bad public key length: " + strconv.Itoa(l))
}
if len(sig) != SignatureSize || sig[63]&224 != 0 {
return false
}
var A edwards25519.ExtendedGroupElement
var publicKeyBytes [32]byte
copy(publicKeyBytes[:], publicKey)
if !A.FromBytes(&publicKeyBytes) {
return false
}
edwards25519.FeNeg(&A.X, &A.X)
edwards25519.FeNeg(&A.T, &A.T)
h := sha512.New()
h.Write(sig[:32])
h.Write(publicKey[:])
h.Write(message)
var digest [64]byte
h.Sum(digest[:0])
var hReduced [32]byte
edwards25519.ScReduce(&hReduced, &digest)
var R edwards25519.ProjectiveGroupElement
var s [32]byte
copy(s[:], sig[32:])
// https://tools.ietf.org/html/rfc8032#section-5.1.7 requires that s be in
// the range [0, order) in order to prevent signature malleability.
if !edwards25519.ScMinimal(&s) {
return false
}
edwards25519.GeDoubleScalarMultVartime(&R, &hReduced, &A, &s)
var checkR [32]byte
R.ToBytes(&checkR)
return bytes.Equal(sig[:32], checkR[:])
return ed25519.Verify(publicKey, message, sig)
}

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@ -1,74 +0,0 @@
// Copyright 2019 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.
//go:build go1.13
// +build go1.13
// Package ed25519 implements the Ed25519 signature algorithm. See
// https://ed25519.cr.yp.to/.
//
// These functions are also compatible with the “Ed25519” function defined in
// RFC 8032. However, unlike RFC 8032's formulation, this package's private key
// representation includes a public key suffix to make multiple signing
// operations with the same key more efficient. This package refers to the RFC
// 8032 private key as the “seed”.
//
// Beginning with Go 1.13, the functionality of this package was moved to the
// standard library as crypto/ed25519. This package only acts as a compatibility
// wrapper.
package ed25519
import (
"crypto/ed25519"
"io"
)
const (
// PublicKeySize is the size, in bytes, of public keys as used in this package.
PublicKeySize = 32
// PrivateKeySize is the size, in bytes, of private keys as used in this package.
PrivateKeySize = 64
// SignatureSize is the size, in bytes, of signatures generated and verified by this package.
SignatureSize = 64
// SeedSize is the size, in bytes, of private key seeds. These are the private key representations used by RFC 8032.
SeedSize = 32
)
// PublicKey is the type of Ed25519 public keys.
//
// This type is an alias for crypto/ed25519's PublicKey type.
// See the crypto/ed25519 package for the methods on this type.
type PublicKey = ed25519.PublicKey
// PrivateKey is the type of Ed25519 private keys. It implements crypto.Signer.
//
// This type is an alias for crypto/ed25519's PrivateKey type.
// See the crypto/ed25519 package for the methods on this type.
type PrivateKey = ed25519.PrivateKey
// GenerateKey generates a public/private key pair using entropy from rand.
// If rand is nil, crypto/rand.Reader will be used.
func GenerateKey(rand io.Reader) (PublicKey, PrivateKey, error) {
return ed25519.GenerateKey(rand)
}
// NewKeyFromSeed calculates a private key from a seed. It will panic if
// len(seed) is not SeedSize. This function is provided for interoperability
// with RFC 8032. RFC 8032's private keys correspond to seeds in this
// package.
func NewKeyFromSeed(seed []byte) PrivateKey {
return ed25519.NewKeyFromSeed(seed)
}
// Sign signs the message with privateKey and returns a signature. It will
// panic if len(privateKey) is not PrivateKeySize.
func Sign(privateKey PrivateKey, message []byte) []byte {
return ed25519.Sign(privateKey, message)
}
// Verify reports whether sig is a valid signature of message by publicKey. It
// will panic if len(publicKey) is not PublicKeySize.
func Verify(publicKey PublicKey, message, sig []byte) bool {
return ed25519.Verify(publicKey, message, sig)
}

File diff suppressed because it is too large Load Diff

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@ -279,7 +279,6 @@ const (
// finalize completes the modular reduction of h and computes
//
// out = h + s mod 2¹²⁸
//
func finalize(out *[TagSize]byte, h *[3]uint64, s *[2]uint64) {
h0, h1, h2 := h[0], h[1], h[2]

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@ -14,6 +14,7 @@ import (
// updateVX is an assembly implementation of Poly1305 that uses vector
// instructions. It must only be called if the vector facility (vx) is
// available.
//
//go:noescape
func updateVX(state *macState, msg []byte)

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@ -14,8 +14,10 @@ import (
"time"
)
// These constants from [PROTOCOL.certkeys] represent the algorithm names
// for certificate types supported by this package.
// Certificate algorithm names from [PROTOCOL.certkeys]. These values can appear
// in Certificate.Type, PublicKey.Type, and ClientConfig.HostKeyAlgorithms.
// Unlike key algorithm names, these are not passed to AlgorithmSigner and don't
// appear in the Signature.Format field.
const (
CertAlgoRSAv01 = "ssh-rsa-cert-v01@openssh.com"
CertAlgoDSAv01 = "ssh-dss-cert-v01@openssh.com"
@ -25,6 +27,21 @@ const (
CertAlgoSKECDSA256v01 = "sk-ecdsa-sha2-nistp256-cert-v01@openssh.com"
CertAlgoED25519v01 = "ssh-ed25519-cert-v01@openssh.com"
CertAlgoSKED25519v01 = "sk-ssh-ed25519-cert-v01@openssh.com"
// CertAlgoRSASHA256v01 and CertAlgoRSASHA512v01 can't appear as a
// Certificate.Type (or PublicKey.Type), but only in
// ClientConfig.HostKeyAlgorithms.
CertAlgoRSASHA256v01 = "rsa-sha2-256-cert-v01@openssh.com"
CertAlgoRSASHA512v01 = "rsa-sha2-512-cert-v01@openssh.com"
)
const (
// Deprecated: use CertAlgoRSAv01.
CertSigAlgoRSAv01 = CertAlgoRSAv01
// Deprecated: use CertAlgoRSASHA256v01.
CertSigAlgoRSASHA2256v01 = CertAlgoRSASHA256v01
// Deprecated: use CertAlgoRSASHA512v01.
CertSigAlgoRSASHA2512v01 = CertAlgoRSASHA512v01
)
// Certificate types distinguish between host and user
@ -423,6 +440,16 @@ func (c *Certificate) SignCert(rand io.Reader, authority Signer) error {
}
c.SignatureKey = authority.PublicKey()
// Default to KeyAlgoRSASHA512 for ssh-rsa signers.
if v, ok := authority.(AlgorithmSigner); ok && v.PublicKey().Type() == KeyAlgoRSA {
sig, err := v.SignWithAlgorithm(rand, c.bytesForSigning(), KeyAlgoRSASHA512)
if err != nil {
return err
}
c.Signature = sig
return nil
}
sig, err := authority.Sign(rand, c.bytesForSigning())
if err != nil {
return err
@ -431,26 +458,40 @@ func (c *Certificate) SignCert(rand io.Reader, authority Signer) error {
return nil
}
var certAlgoNames = map[string]string{
KeyAlgoRSA: CertAlgoRSAv01,
KeyAlgoDSA: CertAlgoDSAv01,
KeyAlgoECDSA256: CertAlgoECDSA256v01,
KeyAlgoECDSA384: CertAlgoECDSA384v01,
KeyAlgoECDSA521: CertAlgoECDSA521v01,
KeyAlgoSKECDSA256: CertAlgoSKECDSA256v01,
KeyAlgoED25519: CertAlgoED25519v01,
KeyAlgoSKED25519: CertAlgoSKED25519v01,
// certKeyAlgoNames is a mapping from known certificate algorithm names to the
// corresponding public key signature algorithm.
var certKeyAlgoNames = map[string]string{
CertAlgoRSAv01: KeyAlgoRSA,
CertAlgoRSASHA256v01: KeyAlgoRSASHA256,
CertAlgoRSASHA512v01: KeyAlgoRSASHA512,
CertAlgoDSAv01: KeyAlgoDSA,
CertAlgoECDSA256v01: KeyAlgoECDSA256,
CertAlgoECDSA384v01: KeyAlgoECDSA384,
CertAlgoECDSA521v01: KeyAlgoECDSA521,
CertAlgoSKECDSA256v01: KeyAlgoSKECDSA256,
CertAlgoED25519v01: KeyAlgoED25519,
CertAlgoSKED25519v01: KeyAlgoSKED25519,
}
// certToPrivAlgo returns the underlying algorithm for a certificate algorithm.
// Panics if a non-certificate algorithm is passed.
func certToPrivAlgo(algo string) string {
for privAlgo, pubAlgo := range certAlgoNames {
if pubAlgo == algo {
return privAlgo
// underlyingAlgo returns the signature algorithm associated with algo (which is
// an advertised or negotiated public key or host key algorithm). These are
// usually the same, except for certificate algorithms.
func underlyingAlgo(algo string) string {
if a, ok := certKeyAlgoNames[algo]; ok {
return a
}
return algo
}
// certificateAlgo returns the certificate algorithms that uses the provided
// underlying signature algorithm.
func certificateAlgo(algo string) (certAlgo string, ok bool) {
for certName, algoName := range certKeyAlgoNames {
if algoName == algo {
return certName, true
}
}
panic("unknown cert algorithm")
return "", false
}
func (cert *Certificate) bytesForSigning() []byte {
@ -494,13 +535,13 @@ func (c *Certificate) Marshal() []byte {
return result
}
// Type returns the key name. It is part of the PublicKey interface.
// Type returns the certificate algorithm name. It is part of the PublicKey interface.
func (c *Certificate) Type() string {
algo, ok := certAlgoNames[c.Key.Type()]
certName, ok := certificateAlgo(c.Key.Type())
if !ok {
panic("unknown cert key type " + c.Key.Type())
panic("unknown certificate type for key type " + c.Key.Type())
}
return algo
return certName
}
// Verify verifies a signature against the certificate's public

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@ -394,6 +394,10 @@ func (c *gcmCipher) readCipherPacket(seqNum uint32, r io.Reader) ([]byte, error)
}
c.incIV()
if len(plain) == 0 {
return nil, errors.New("ssh: empty packet")
}
padding := plain[0]
if padding < 4 {
// padding is a byte, so it automatically satisfies
@ -710,6 +714,10 @@ func (c *chacha20Poly1305Cipher) readCipherPacket(seqNum uint32, r io.Reader) ([
plain := c.buf[4:contentEnd]
s.XORKeyStream(plain, plain)
if len(plain) == 0 {
return nil, errors.New("ssh: empty packet")
}
padding := plain[0]
if padding < 4 {
// padding is a byte, so it automatically satisfies

View File

@ -113,14 +113,18 @@ func (c *connection) clientHandshake(dialAddress string, config *ClientConfig) e
return c.clientAuthenticate(config)
}
// verifyHostKeySignature verifies the host key obtained in the key
// exchange.
func verifyHostKeySignature(hostKey PublicKey, result *kexResult) error {
// verifyHostKeySignature verifies the host key obtained in the key exchange.
// algo is the negotiated algorithm, and may be a certificate type.
func verifyHostKeySignature(hostKey PublicKey, algo string, result *kexResult) error {
sig, rest, ok := parseSignatureBody(result.Signature)
if len(rest) > 0 || !ok {
return errors.New("ssh: signature parse error")
}
if a := underlyingAlgo(algo); sig.Format != a {
return fmt.Errorf("ssh: invalid signature algorithm %q, expected %q", sig.Format, a)
}
return hostKey.Verify(result.H, sig)
}
@ -224,11 +228,11 @@ type ClientConfig struct {
// be used for the connection. If empty, a reasonable default is used.
ClientVersion string
// HostKeyAlgorithms lists the key types that the client will
// accept from the server as host key, in order of
// HostKeyAlgorithms lists the public key algorithms that the client will
// accept from the server for host key authentication, in order of
// preference. If empty, a reasonable default is used. Any
// string returned from PublicKey.Type method may be used, or
// any of the CertAlgoXxxx and KeyAlgoXxxx constants.
// string returned from a PublicKey.Type method may be used, or
// any of the CertAlgo and KeyAlgo constants.
HostKeyAlgorithms []string
// Timeout is the maximum amount of time for the TCP connection to establish.

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@ -9,6 +9,7 @@ import (
"errors"
"fmt"
"io"
"strings"
)
type authResult int
@ -29,6 +30,33 @@ func (c *connection) clientAuthenticate(config *ClientConfig) error {
if err != nil {
return err
}
// The server may choose to send a SSH_MSG_EXT_INFO at this point (if we
// advertised willingness to receive one, which we always do) or not. See
// RFC 8308, Section 2.4.
extensions := make(map[string][]byte)
if len(packet) > 0 && packet[0] == msgExtInfo {
var extInfo extInfoMsg
if err := Unmarshal(packet, &extInfo); err != nil {
return err
}
payload := extInfo.Payload
for i := uint32(0); i < extInfo.NumExtensions; i++ {
name, rest, ok := parseString(payload)
if !ok {
return parseError(msgExtInfo)
}
value, rest, ok := parseString(rest)
if !ok {
return parseError(msgExtInfo)
}
extensions[string(name)] = value
payload = rest
}
packet, err = c.transport.readPacket()
if err != nil {
return err
}
}
var serviceAccept serviceAcceptMsg
if err := Unmarshal(packet, &serviceAccept); err != nil {
return err
@ -41,7 +69,7 @@ func (c *connection) clientAuthenticate(config *ClientConfig) error {
sessionID := c.transport.getSessionID()
for auth := AuthMethod(new(noneAuth)); auth != nil; {
ok, methods, err := auth.auth(sessionID, config.User, c.transport, config.Rand)
ok, methods, err := auth.auth(sessionID, config.User, c.transport, config.Rand, extensions)
if err != nil {
return err
}
@ -93,7 +121,7 @@ type AuthMethod interface {
// If authentication is not successful, a []string of alternative
// method names is returned. If the slice is nil, it will be ignored
// and the previous set of possible methods will be reused.
auth(session []byte, user string, p packetConn, rand io.Reader) (authResult, []string, error)
auth(session []byte, user string, p packetConn, rand io.Reader, extensions map[string][]byte) (authResult, []string, error)
// method returns the RFC 4252 method name.
method() string
@ -102,7 +130,7 @@ type AuthMethod interface {
// "none" authentication, RFC 4252 section 5.2.
type noneAuth int
func (n *noneAuth) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
func (n *noneAuth) auth(session []byte, user string, c packetConn, rand io.Reader, _ map[string][]byte) (authResult, []string, error) {
if err := c.writePacket(Marshal(&userAuthRequestMsg{
User: user,
Service: serviceSSH,
@ -122,7 +150,7 @@ func (n *noneAuth) method() string {
// a function call, e.g. by prompting the user.
type passwordCallback func() (password string, err error)
func (cb passwordCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
func (cb passwordCallback) auth(session []byte, user string, c packetConn, rand io.Reader, _ map[string][]byte) (authResult, []string, error) {
type passwordAuthMsg struct {
User string `sshtype:"50"`
Service string
@ -189,7 +217,46 @@ func (cb publicKeyCallback) method() string {
return "publickey"
}
func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
func pickSignatureAlgorithm(signer Signer, extensions map[string][]byte) (as AlgorithmSigner, algo string) {
keyFormat := signer.PublicKey().Type()
// Like in sendKexInit, if the public key implements AlgorithmSigner we
// assume it supports all algorithms, otherwise only the key format one.
as, ok := signer.(AlgorithmSigner)
if !ok {
return algorithmSignerWrapper{signer}, keyFormat
}
extPayload, ok := extensions["server-sig-algs"]
if !ok {
// If there is no "server-sig-algs" extension, fall back to the key
// format algorithm.
return as, keyFormat
}
// The server-sig-algs extension only carries underlying signature
// algorithm, but we are trying to select a protocol-level public key
// algorithm, which might be a certificate type. Extend the list of server
// supported algorithms to include the corresponding certificate algorithms.
serverAlgos := strings.Split(string(extPayload), ",")
for _, algo := range serverAlgos {
if certAlgo, ok := certificateAlgo(algo); ok {
serverAlgos = append(serverAlgos, certAlgo)
}
}
keyAlgos := algorithmsForKeyFormat(keyFormat)
algo, err := findCommon("public key signature algorithm", keyAlgos, serverAlgos)
if err != nil {
// If there is no overlap, try the key anyway with the key format
// algorithm, to support servers that fail to list all supported
// algorithms.
return as, keyFormat
}
return as, algo
}
func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand io.Reader, extensions map[string][]byte) (authResult, []string, error) {
// 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
@ -201,7 +268,10 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
}
var methods []string
for _, signer := range signers {
ok, err := validateKey(signer.PublicKey(), user, c)
pub := signer.PublicKey()
as, algo := pickSignatureAlgorithm(signer, extensions)
ok, err := validateKey(pub, algo, user, c)
if err != nil {
return authFailure, nil, err
}
@ -209,13 +279,13 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
continue
}
pub := signer.PublicKey()
pubKey := pub.Marshal()
sign, err := signer.Sign(rand, buildDataSignedForAuth(session, userAuthRequestMsg{
data := buildDataSignedForAuth(session, userAuthRequestMsg{
User: user,
Service: serviceSSH,
Method: cb.method(),
}, []byte(pub.Type()), pubKey))
}, algo, pubKey)
sign, err := as.SignWithAlgorithm(rand, data, underlyingAlgo(algo))
if err != nil {
return authFailure, nil, err
}
@ -229,7 +299,7 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
Service: serviceSSH,
Method: cb.method(),
HasSig: true,
Algoname: pub.Type(),
Algoname: algo,
PubKey: pubKey,
Sig: sig,
}
@ -266,26 +336,25 @@ func containsMethod(methods []string, method string) bool {
}
// validateKey validates the key provided is acceptable to the server.
func validateKey(key PublicKey, user string, c packetConn) (bool, error) {
func validateKey(key PublicKey, algo string, user string, c packetConn) (bool, error) {
pubKey := key.Marshal()
msg := publickeyAuthMsg{
User: user,
Service: serviceSSH,
Method: "publickey",
HasSig: false,
Algoname: key.Type(),
Algoname: algo,
PubKey: pubKey,
}
if err := c.writePacket(Marshal(&msg)); err != nil {
return false, err
}
return confirmKeyAck(key, c)
return confirmKeyAck(key, algo, c)
}
func confirmKeyAck(key PublicKey, c packetConn) (bool, error) {
func confirmKeyAck(key PublicKey, algo string, c packetConn) (bool, error) {
pubKey := key.Marshal()
algoname := key.Type()
for {
packet, err := c.readPacket()
@ -302,14 +371,14 @@ func confirmKeyAck(key PublicKey, c packetConn) (bool, error) {
if err := Unmarshal(packet, &msg); err != nil {
return false, err
}
if msg.Algo != algoname || !bytes.Equal(msg.PubKey, pubKey) {
if msg.Algo != algo || !bytes.Equal(msg.PubKey, pubKey) {
return false, nil
}
return true, nil
case msgUserAuthFailure:
return false, nil
default:
return false, unexpectedMessageError(msgUserAuthSuccess, packet[0])
return false, unexpectedMessageError(msgUserAuthPubKeyOk, packet[0])
}
}
}
@ -330,6 +399,7 @@ func PublicKeysCallback(getSigners func() (signers []Signer, err error)) AuthMet
// along with a list of remaining authentication methods to try next and
// an error if an unexpected response was received.
func handleAuthResponse(c packetConn) (authResult, []string, error) {
gotMsgExtInfo := false
for {
packet, err := c.readPacket()
if err != nil {
@ -341,6 +411,12 @@ func handleAuthResponse(c packetConn) (authResult, []string, error) {
if err := handleBannerResponse(c, packet); err != nil {
return authFailure, nil, err
}
case msgExtInfo:
// Ignore post-authentication RFC 8308 extensions, once.
if gotMsgExtInfo {
return authFailure, nil, unexpectedMessageError(msgUserAuthSuccess, packet[0])
}
gotMsgExtInfo = true
case msgUserAuthFailure:
var msg userAuthFailureMsg
if err := Unmarshal(packet, &msg); err != nil {
@ -380,10 +456,10 @@ func handleBannerResponse(c packetConn, packet []byte) error {
// disabling echoing (e.g. for passwords), and return all the answers.
// Challenge may be called multiple times in a single session. After
// successful authentication, the server may send a challenge with no
// questions, for which the user and instruction messages should be
// questions, for which the name and instruction messages should be
// printed. RFC 4256 section 3.3 details how the UI should behave for
// both CLI and GUI environments.
type KeyboardInteractiveChallenge func(user, instruction string, questions []string, echos []bool) (answers []string, err error)
type KeyboardInteractiveChallenge func(name, instruction string, questions []string, echos []bool) (answers []string, err error)
// KeyboardInteractive returns an AuthMethod using a prompt/response
// sequence controlled by the server.
@ -395,7 +471,7 @@ func (cb KeyboardInteractiveChallenge) method() string {
return "keyboard-interactive"
}
func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packetConn, rand io.Reader, _ map[string][]byte) (authResult, []string, error) {
type initiateMsg struct {
User string `sshtype:"50"`
Service string
@ -412,6 +488,7 @@ func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packe
return authFailure, nil, err
}
gotMsgExtInfo := false
for {
packet, err := c.readPacket()
if err != nil {
@ -425,6 +502,13 @@ func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packe
return authFailure, nil, err
}
continue
case msgExtInfo:
// Ignore post-authentication RFC 8308 extensions, once.
if gotMsgExtInfo {
return authFailure, nil, unexpectedMessageError(msgUserAuthInfoRequest, packet[0])
}
gotMsgExtInfo = true
continue
case msgUserAuthInfoRequest:
// OK
case msgUserAuthFailure:
@ -465,7 +549,7 @@ func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packe
return authFailure, nil, errors.New("ssh: extra data following keyboard-interactive pairs")
}
answers, err := cb(msg.User, msg.Instruction, prompts, echos)
answers, err := cb(msg.Name, msg.Instruction, prompts, echos)
if err != nil {
return authFailure, nil, err
}
@ -497,9 +581,9 @@ type retryableAuthMethod struct {
maxTries int
}
func (r *retryableAuthMethod) auth(session []byte, user string, c packetConn, rand io.Reader) (ok authResult, methods []string, err error) {
func (r *retryableAuthMethod) auth(session []byte, user string, c packetConn, rand io.Reader, extensions map[string][]byte) (ok authResult, methods []string, err error) {
for i := 0; r.maxTries <= 0 || i < r.maxTries; i++ {
ok, methods, err = r.authMethod.auth(session, user, c, rand)
ok, methods, err = r.authMethod.auth(session, user, c, rand, extensions)
if ok != authFailure || err != nil { // either success, partial success or error terminate
return ok, methods, err
}
@ -542,7 +626,7 @@ type gssAPIWithMICCallback struct {
target string
}
func (g *gssAPIWithMICCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
func (g *gssAPIWithMICCallback) auth(session []byte, user string, c packetConn, rand io.Reader, _ map[string][]byte) (authResult, []string, error) {
m := &userAuthRequestMsg{
User: user,
Service: serviceSSH,

View File

@ -44,11 +44,11 @@ var preferredCiphers = []string{
// supportedKexAlgos specifies the supported key-exchange algorithms in
// preference order.
var supportedKexAlgos = []string{
kexAlgoCurve25519SHA256,
kexAlgoCurve25519SHA256, kexAlgoCurve25519SHA256LibSSH,
// P384 and P521 are not constant-time yet, but since we don't
// reuse ephemeral keys, using them for ECDH should be OK.
kexAlgoECDH256, kexAlgoECDH384, kexAlgoECDH521,
kexAlgoDH14SHA1, kexAlgoDH1SHA1,
kexAlgoDH14SHA256, kexAlgoDH14SHA1, kexAlgoDH1SHA1,
}
// serverForbiddenKexAlgos contains key exchange algorithms, that are forbidden
@ -61,18 +61,20 @@ var serverForbiddenKexAlgos = map[string]struct{}{
// preferredKexAlgos specifies the default preference for key-exchange algorithms
// in preference order.
var preferredKexAlgos = []string{
kexAlgoCurve25519SHA256,
kexAlgoCurve25519SHA256, kexAlgoCurve25519SHA256LibSSH,
kexAlgoECDH256, kexAlgoECDH384, kexAlgoECDH521,
kexAlgoDH14SHA1,
kexAlgoDH14SHA256, kexAlgoDH14SHA1,
}
// supportedHostKeyAlgos specifies the supported host-key algorithms (i.e. methods
// of authenticating servers) in preference order.
var supportedHostKeyAlgos = []string{
CertAlgoRSASHA512v01, CertAlgoRSASHA256v01,
CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01,
CertAlgoECDSA384v01, CertAlgoECDSA521v01, CertAlgoED25519v01,
KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521,
KeyAlgoRSASHA512, KeyAlgoRSASHA256,
KeyAlgoRSA, KeyAlgoDSA,
KeyAlgoED25519,
@ -87,19 +89,33 @@ var supportedMACs = []string{
var supportedCompressions = []string{compressionNone}
// hashFuncs keeps the mapping of supported algorithms to their respective
// hashes needed for signature verification.
// hashFuncs keeps the mapping of supported signature algorithms to their
// respective hashes needed for signing and verification.
var hashFuncs = map[string]crypto.Hash{
KeyAlgoRSA: crypto.SHA1,
KeyAlgoRSASHA256: crypto.SHA256,
KeyAlgoRSASHA512: crypto.SHA512,
KeyAlgoDSA: crypto.SHA1,
KeyAlgoECDSA256: crypto.SHA256,
KeyAlgoECDSA384: crypto.SHA384,
KeyAlgoECDSA521: crypto.SHA512,
CertAlgoRSAv01: crypto.SHA1,
CertAlgoDSAv01: crypto.SHA1,
CertAlgoECDSA256v01: crypto.SHA256,
CertAlgoECDSA384v01: crypto.SHA384,
CertAlgoECDSA521v01: crypto.SHA512,
// KeyAlgoED25519 doesn't pre-hash.
KeyAlgoSKECDSA256: crypto.SHA256,
KeyAlgoSKED25519: crypto.SHA256,
}
// algorithmsForKeyFormat returns the supported signature algorithms for a given
// public key format (PublicKey.Type), in order of preference. See RFC 8332,
// Section 2. See also the note in sendKexInit on backwards compatibility.
func algorithmsForKeyFormat(keyFormat string) []string {
switch keyFormat {
case KeyAlgoRSA:
return []string{KeyAlgoRSASHA256, KeyAlgoRSASHA512, KeyAlgoRSA}
case CertAlgoRSAv01:
return []string{CertAlgoRSASHA256v01, CertAlgoRSASHA512v01, CertAlgoRSAv01}
default:
return []string{keyFormat}
}
}
// unexpectedMessageError results when the SSH message that we received didn't
@ -146,6 +162,11 @@ func (a *directionAlgorithms) rekeyBytes() int64 {
return 1 << 30
}
var aeadCiphers = map[string]bool{
gcmCipherID: true,
chacha20Poly1305ID: true,
}
type algorithms struct {
kex string
hostKey string
@ -181,15 +202,19 @@ func findAgreedAlgorithms(isClient bool, clientKexInit, serverKexInit *kexInitMs
return
}
if !aeadCiphers[ctos.Cipher] {
ctos.MAC, err = findCommon("client to server MAC", clientKexInit.MACsClientServer, serverKexInit.MACsClientServer)
if err != nil {
return
}
}
if !aeadCiphers[stoc.Cipher] {
stoc.MAC, err = findCommon("server to client MAC", clientKexInit.MACsServerClient, serverKexInit.MACsServerClient)
if err != nil {
return
}
}
ctos.Compression, err = findCommon("client to server compression", clientKexInit.CompressionClientServer, serverKexInit.CompressionClientServer)
if err != nil {
@ -272,8 +297,9 @@ func (c *Config) SetDefaults() {
}
// buildDataSignedForAuth returns the data that is signed in order to prove
// possession of a private key. See RFC 4252, section 7.
func buildDataSignedForAuth(sessionID []byte, req userAuthRequestMsg, algo, pubKey []byte) []byte {
// possession of a private key. See RFC 4252, section 7. algo is the advertised
// algorithm, and may be a certificate type.
func buildDataSignedForAuth(sessionID []byte, req userAuthRequestMsg, algo string, pubKey []byte) []byte {
data := struct {
Session []byte
Type byte
@ -281,7 +307,7 @@ func buildDataSignedForAuth(sessionID []byte, req userAuthRequestMsg, algo, pubK
Service string
Method string
Sign bool
Algo []byte
Algo string
PubKey []byte
}{
sessionID,

View File

@ -12,6 +12,7 @@ the multiplexed nature of SSH is exposed to users that wish to support
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

View File

@ -455,14 +455,38 @@ func (t *handshakeTransport) sendKexInit() error {
}
io.ReadFull(rand.Reader, msg.Cookie[:])
if len(t.hostKeys) > 0 {
isServer := len(t.hostKeys) > 0
if isServer {
for _, k := range t.hostKeys {
msg.ServerHostKeyAlgos = append(
msg.ServerHostKeyAlgos, k.PublicKey().Type())
// If k is an AlgorithmSigner, presume it supports all signature algorithms
// associated with the key format. (Ideally AlgorithmSigner would have a
// method to advertise supported algorithms, but it doesn't. This means that
// adding support for a new algorithm is a breaking change, as we will
// immediately negotiate it even if existing implementations don't support
// it. If that ever happens, we'll have to figure something out.)
// If k is not an AlgorithmSigner, we can only assume it only supports the
// algorithms that matches the key format. (This means that Sign can't pick
// a different default.)
keyFormat := k.PublicKey().Type()
if _, ok := k.(AlgorithmSigner); ok {
msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, algorithmsForKeyFormat(keyFormat)...)
} else {
msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, keyFormat)
}
}
} else {
msg.ServerHostKeyAlgos = t.hostKeyAlgorithms
// As a client we opt in to receiving SSH_MSG_EXT_INFO so we know what
// algorithms the server supports for public key authentication. See RFC
// 8308, Section 2.1.
if firstKeyExchange := t.sessionID == nil; firstKeyExchange {
msg.KexAlgos = make([]string, 0, len(t.config.KeyExchanges)+1)
msg.KexAlgos = append(msg.KexAlgos, t.config.KeyExchanges...)
msg.KexAlgos = append(msg.KexAlgos, "ext-info-c")
}
}
packet := Marshal(msg)
// writePacket destroys the contents, so save a copy.
@ -582,9 +606,9 @@ func (t *handshakeTransport) enterKeyExchange(otherInitPacket []byte) error {
var result *kexResult
if len(t.hostKeys) > 0 {
result, err = t.server(kex, t.algorithms, &magics)
result, err = t.server(kex, &magics)
} else {
result, err = t.client(kex, t.algorithms, &magics)
result, err = t.client(kex, &magics)
}
if err != nil {
@ -611,19 +635,52 @@ func (t *handshakeTransport) enterKeyExchange(otherInitPacket []byte) error {
return nil
}
func (t *handshakeTransport) server(kex kexAlgorithm, algs *algorithms, magics *handshakeMagics) (*kexResult, error) {
var hostKey Signer
for _, k := range t.hostKeys {
if algs.hostKey == k.PublicKey().Type() {
hostKey = k
}
// algorithmSignerWrapper is an AlgorithmSigner that only supports the default
// key format algorithm.
//
// This is technically a violation of the AlgorithmSigner interface, but it
// should be unreachable given where we use this. Anyway, at least it returns an
// error instead of panicing or producing an incorrect signature.
type algorithmSignerWrapper struct {
Signer
}
r, err := kex.Server(t.conn, t.config.Rand, magics, hostKey)
func (a algorithmSignerWrapper) SignWithAlgorithm(rand io.Reader, data []byte, algorithm string) (*Signature, error) {
if algorithm != underlyingAlgo(a.PublicKey().Type()) {
return nil, errors.New("ssh: internal error: algorithmSignerWrapper invoked with non-default algorithm")
}
return a.Sign(rand, data)
}
func pickHostKey(hostKeys []Signer, algo string) AlgorithmSigner {
for _, k := range hostKeys {
if algo == k.PublicKey().Type() {
return algorithmSignerWrapper{k}
}
k, ok := k.(AlgorithmSigner)
if !ok {
continue
}
for _, a := range algorithmsForKeyFormat(k.PublicKey().Type()) {
if algo == a {
return k
}
}
}
return nil
}
func (t *handshakeTransport) server(kex kexAlgorithm, magics *handshakeMagics) (*kexResult, error) {
hostKey := pickHostKey(t.hostKeys, t.algorithms.hostKey)
if hostKey == nil {
return nil, errors.New("ssh: internal error: negotiated unsupported signature type")
}
r, err := kex.Server(t.conn, t.config.Rand, magics, hostKey, t.algorithms.hostKey)
return r, err
}
func (t *handshakeTransport) client(kex kexAlgorithm, algs *algorithms, magics *handshakeMagics) (*kexResult, error) {
func (t *handshakeTransport) client(kex kexAlgorithm, magics *handshakeMagics) (*kexResult, error) {
result, err := kex.Client(t.conn, t.config.Rand, magics)
if err != nil {
return nil, err
@ -634,7 +691,7 @@ func (t *handshakeTransport) client(kex kexAlgorithm, algs *algorithms, magics *
return nil, err
}
if err := verifyHostKeySignature(hostKey, result); err != nil {
if err := verifyHostKeySignature(hostKey, t.algorithms.hostKey, result); err != nil {
return nil, err
}

170
vendor/golang.org/x/crypto/ssh/kex.go generated vendored
View File

@ -22,10 +22,12 @@ import (
const (
kexAlgoDH1SHA1 = "diffie-hellman-group1-sha1"
kexAlgoDH14SHA1 = "diffie-hellman-group14-sha1"
kexAlgoDH14SHA256 = "diffie-hellman-group14-sha256"
kexAlgoECDH256 = "ecdh-sha2-nistp256"
kexAlgoECDH384 = "ecdh-sha2-nistp384"
kexAlgoECDH521 = "ecdh-sha2-nistp521"
kexAlgoCurve25519SHA256 = "curve25519-sha256@libssh.org"
kexAlgoCurve25519SHA256LibSSH = "curve25519-sha256@libssh.org"
kexAlgoCurve25519SHA256 = "curve25519-sha256"
// For the following kex only the client half contains a production
// ready implementation. The server half only consists of a minimal
@ -75,8 +77,9 @@ func (m *handshakeMagics) write(w io.Writer) {
// kexAlgorithm abstracts different key exchange algorithms.
type kexAlgorithm interface {
// Server runs server-side key agreement, signing the result
// with a hostkey.
Server(p packetConn, rand io.Reader, magics *handshakeMagics, s Signer) (*kexResult, error)
// with a hostkey. algo is the negotiated algorithm, and may
// be a certificate type.
Server(p packetConn, rand io.Reader, magics *handshakeMagics, s AlgorithmSigner, algo string) (*kexResult, error)
// Client runs the client-side key agreement. Caller is
// responsible for verifying the host key signature.
@ -86,6 +89,7 @@ type kexAlgorithm interface {
// dhGroup is a multiplicative group suitable for implementing Diffie-Hellman key agreement.
type dhGroup struct {
g, p, pMinus1 *big.Int
hashFunc crypto.Hash
}
func (group *dhGroup) diffieHellman(theirPublic, myPrivate *big.Int) (*big.Int, error) {
@ -96,8 +100,6 @@ func (group *dhGroup) diffieHellman(theirPublic, myPrivate *big.Int) (*big.Int,
}
func (group *dhGroup) Client(c packetConn, randSource io.Reader, magics *handshakeMagics) (*kexResult, error) {
hashFunc := crypto.SHA1
var x *big.Int
for {
var err error
@ -132,7 +134,7 @@ func (group *dhGroup) Client(c packetConn, randSource io.Reader, magics *handsha
return nil, err
}
h := hashFunc.New()
h := group.hashFunc.New()
magics.write(h)
writeString(h, kexDHReply.HostKey)
writeInt(h, X)
@ -146,12 +148,11 @@ func (group *dhGroup) Client(c packetConn, randSource io.Reader, magics *handsha
K: K,
HostKey: kexDHReply.HostKey,
Signature: kexDHReply.Signature,
Hash: crypto.SHA1,
Hash: group.hashFunc,
}, nil
}
func (group *dhGroup) Server(c packetConn, randSource io.Reader, magics *handshakeMagics, priv Signer) (result *kexResult, err error) {
hashFunc := crypto.SHA1
func (group *dhGroup) Server(c packetConn, randSource io.Reader, magics *handshakeMagics, priv AlgorithmSigner, algo string) (result *kexResult, err error) {
packet, err := c.readPacket()
if err != nil {
return
@ -179,7 +180,7 @@ func (group *dhGroup) Server(c packetConn, randSource io.Reader, magics *handsha
hostKeyBytes := priv.PublicKey().Marshal()
h := hashFunc.New()
h := group.hashFunc.New()
magics.write(h)
writeString(h, hostKeyBytes)
writeInt(h, kexDHInit.X)
@ -193,7 +194,7 @@ func (group *dhGroup) Server(c packetConn, randSource io.Reader, magics *handsha
// H is already a hash, but the hostkey signing will apply its
// own key-specific hash algorithm.
sig, err := signAndMarshal(priv, randSource, H)
sig, err := signAndMarshal(priv, randSource, H, algo)
if err != nil {
return nil, err
}
@ -211,7 +212,7 @@ func (group *dhGroup) Server(c packetConn, randSource io.Reader, magics *handsha
K: K,
HostKey: hostKeyBytes,
Signature: sig,
Hash: crypto.SHA1,
Hash: group.hashFunc,
}, err
}
@ -314,7 +315,7 @@ func validateECPublicKey(curve elliptic.Curve, x, y *big.Int) bool {
return true
}
func (kex *ecdh) Server(c packetConn, rand io.Reader, magics *handshakeMagics, priv Signer) (result *kexResult, err error) {
func (kex *ecdh) Server(c packetConn, rand io.Reader, magics *handshakeMagics, priv AlgorithmSigner, algo string) (result *kexResult, err error) {
packet, err := c.readPacket()
if err != nil {
return nil, err
@ -359,7 +360,7 @@ func (kex *ecdh) Server(c packetConn, rand io.Reader, magics *handshakeMagics, p
// H is already a hash, but the hostkey signing will apply its
// own key-specific hash algorithm.
sig, err := signAndMarshal(priv, rand, H)
sig, err := signAndMarshal(priv, rand, H, algo)
if err != nil {
return nil, err
}
@ -384,39 +385,62 @@ func (kex *ecdh) Server(c packetConn, rand io.Reader, magics *handshakeMagics, p
}, nil
}
// ecHash returns the hash to match the given elliptic curve, see RFC
// 5656, section 6.2.1
func ecHash(curve elliptic.Curve) crypto.Hash {
bitSize := curve.Params().BitSize
switch {
case bitSize <= 256:
return crypto.SHA256
case bitSize <= 384:
return crypto.SHA384
}
return crypto.SHA512
}
var kexAlgoMap = map[string]kexAlgorithm{}
func init() {
// This is the group called diffie-hellman-group1-sha1 in RFC
// 4253 and Oakley Group 2 in RFC 2409.
// This is the group called diffie-hellman-group1-sha1 in
// RFC 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,
pMinus1: new(big.Int).Sub(p, bigOne),
hashFunc: crypto.SHA1,
}
// This is the group called diffie-hellman-group14-sha1 in RFC
// 4253 and Oakley Group 14 in RFC 3526.
// This are the groups called diffie-hellman-group14-sha1 and
// diffie-hellman-group14-sha256 in RFC 4253 and RFC 8268,
// and Oakley Group 14 in RFC 3526.
p, _ = new(big.Int).SetString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
kexAlgoMap[kexAlgoDH14SHA1] = &dhGroup{
group14 := &dhGroup{
g: new(big.Int).SetInt64(2),
p: p,
pMinus1: new(big.Int).Sub(p, bigOne),
}
kexAlgoMap[kexAlgoDH14SHA1] = &dhGroup{
g: group14.g, p: group14.p, pMinus1: group14.pMinus1,
hashFunc: crypto.SHA1,
}
kexAlgoMap[kexAlgoDH14SHA256] = &dhGroup{
g: group14.g, p: group14.p, pMinus1: group14.pMinus1,
hashFunc: crypto.SHA256,
}
kexAlgoMap[kexAlgoECDH521] = &ecdh{elliptic.P521()}
kexAlgoMap[kexAlgoECDH384] = &ecdh{elliptic.P384()}
kexAlgoMap[kexAlgoECDH256] = &ecdh{elliptic.P256()}
kexAlgoMap[kexAlgoCurve25519SHA256] = &curve25519sha256{}
kexAlgoMap[kexAlgoCurve25519SHA256LibSSH] = &curve25519sha256{}
kexAlgoMap[kexAlgoDHGEXSHA1] = &dhGEXSHA{hashFunc: crypto.SHA1}
kexAlgoMap[kexAlgoDHGEXSHA256] = &dhGEXSHA{hashFunc: crypto.SHA256}
}
// curve25519sha256 implements the curve25519-sha256@libssh.org key
// agreement protocol, as described in
// https://git.libssh.org/projects/libssh.git/tree/doc/curve25519-sha256@libssh.org.txt
// curve25519sha256 implements the curve25519-sha256 (formerly known as
// curve25519-sha256@libssh.org) key exchange method, as described in RFC 8731.
type curve25519sha256 struct{}
type curve25519KeyPair struct {
@ -486,7 +510,7 @@ func (kex *curve25519sha256) Client(c packetConn, rand io.Reader, magics *handsh
}, nil
}
func (kex *curve25519sha256) Server(c packetConn, rand io.Reader, magics *handshakeMagics, priv Signer) (result *kexResult, err error) {
func (kex *curve25519sha256) Server(c packetConn, rand io.Reader, magics *handshakeMagics, priv AlgorithmSigner, algo string) (result *kexResult, err error) {
packet, err := c.readPacket()
if err != nil {
return
@ -527,7 +551,7 @@ func (kex *curve25519sha256) Server(c packetConn, rand io.Reader, magics *handsh
H := h.Sum(nil)
sig, err := signAndMarshal(priv, rand, H)
sig, err := signAndMarshal(priv, rand, H, algo)
if err != nil {
return nil, err
}
@ -553,7 +577,6 @@ func (kex *curve25519sha256) Server(c packetConn, rand io.Reader, magics *handsh
// diffie-hellman-group-exchange-sha256 key agreement protocols,
// as described in RFC 4419
type dhGEXSHA struct {
g, p *big.Int
hashFunc crypto.Hash
}
@ -563,14 +586,7 @@ const (
dhGroupExchangeMaximumBits = 8192
)
func (gex *dhGEXSHA) diffieHellman(theirPublic, myPrivate *big.Int) (*big.Int, error) {
if theirPublic.Sign() <= 0 || theirPublic.Cmp(gex.p) >= 0 {
return nil, fmt.Errorf("ssh: DH parameter out of bounds")
}
return new(big.Int).Exp(theirPublic, myPrivate, gex.p), nil
}
func (gex dhGEXSHA) Client(c packetConn, randSource io.Reader, magics *handshakeMagics) (*kexResult, error) {
func (gex *dhGEXSHA) Client(c packetConn, randSource io.Reader, magics *handshakeMagics) (*kexResult, error) {
// Send GexRequest
kexDHGexRequest := kexDHGexRequestMsg{
MinBits: dhGroupExchangeMinimumBits,
@ -587,35 +603,29 @@ func (gex dhGEXSHA) Client(c packetConn, randSource io.Reader, magics *handshake
return nil, err
}
var kexDHGexGroup kexDHGexGroupMsg
if err = Unmarshal(packet, &kexDHGexGroup); err != nil {
var msg kexDHGexGroupMsg
if err = Unmarshal(packet, &msg); err != nil {
return nil, err
}
// reject if p's bit length < dhGroupExchangeMinimumBits or > dhGroupExchangeMaximumBits
if kexDHGexGroup.P.BitLen() < dhGroupExchangeMinimumBits || kexDHGexGroup.P.BitLen() > dhGroupExchangeMaximumBits {
return nil, fmt.Errorf("ssh: server-generated gex p is out of range (%d bits)", kexDHGexGroup.P.BitLen())
if msg.P.BitLen() < dhGroupExchangeMinimumBits || msg.P.BitLen() > dhGroupExchangeMaximumBits {
return nil, fmt.Errorf("ssh: server-generated gex p is out of range (%d bits)", msg.P.BitLen())
}
gex.p = kexDHGexGroup.P
gex.g = kexDHGexGroup.G
// Check if g is safe by verifing that g > 1 and g < p - 1
one := big.NewInt(1)
var pMinusOne = &big.Int{}
pMinusOne.Sub(gex.p, one)
if gex.g.Cmp(one) != 1 && gex.g.Cmp(pMinusOne) != -1 {
// Check if g is safe by verifying that 1 < g < p-1
pMinusOne := new(big.Int).Sub(msg.P, bigOne)
if msg.G.Cmp(bigOne) <= 0 || msg.G.Cmp(pMinusOne) >= 0 {
return nil, fmt.Errorf("ssh: server provided gex g is not safe")
}
// Send GexInit
var pHalf = &big.Int{}
pHalf.Rsh(gex.p, 1)
pHalf := new(big.Int).Rsh(msg.P, 1)
x, err := rand.Int(randSource, pHalf)
if err != nil {
return nil, err
}
X := new(big.Int).Exp(gex.g, x, gex.p)
X := new(big.Int).Exp(msg.G, x, msg.P)
kexDHGexInit := kexDHGexInitMsg{
X: X,
}
@ -634,13 +644,13 @@ func (gex dhGEXSHA) Client(c packetConn, randSource io.Reader, magics *handshake
return nil, err
}
kInt, err := gex.diffieHellman(kexDHGexReply.Y, x)
if err != nil {
return nil, err
if kexDHGexReply.Y.Cmp(bigOne) <= 0 || kexDHGexReply.Y.Cmp(pMinusOne) >= 0 {
return nil, errors.New("ssh: DH parameter out of bounds")
}
kInt := new(big.Int).Exp(kexDHGexReply.Y, x, msg.P)
// Check if k is safe by verifing that k > 1 and k < p - 1
if kInt.Cmp(one) != 1 && kInt.Cmp(pMinusOne) != -1 {
// Check if k is safe by verifying that k > 1 and k < p - 1
if kInt.Cmp(bigOne) <= 0 || kInt.Cmp(pMinusOne) >= 0 {
return nil, fmt.Errorf("ssh: derived k is not safe")
}
@ -650,8 +660,8 @@ func (gex dhGEXSHA) Client(c packetConn, randSource io.Reader, magics *handshake
binary.Write(h, binary.BigEndian, uint32(dhGroupExchangeMinimumBits))
binary.Write(h, binary.BigEndian, uint32(dhGroupExchangePreferredBits))
binary.Write(h, binary.BigEndian, uint32(dhGroupExchangeMaximumBits))
writeInt(h, gex.p)
writeInt(h, gex.g)
writeInt(h, msg.P)
writeInt(h, msg.G)
writeInt(h, X)
writeInt(h, kexDHGexReply.Y)
K := make([]byte, intLength(kInt))
@ -670,7 +680,7 @@ func (gex dhGEXSHA) Client(c packetConn, randSource io.Reader, magics *handshake
// Server half implementation of the Diffie Hellman Key Exchange with SHA1 and SHA256.
//
// This is a minimal implementation to satisfy the automated tests.
func (gex dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshakeMagics, priv Signer) (result *kexResult, err error) {
func (gex dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshakeMagics, priv AlgorithmSigner, algo string) (result *kexResult, err error) {
// Receive GexRequest
packet, err := c.readPacket()
if err != nil {
@ -681,35 +691,17 @@ func (gex dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshake
return
}
// smoosh the user's preferred size into our own limits
if kexDHGexRequest.PreferedBits > dhGroupExchangeMaximumBits {
kexDHGexRequest.PreferedBits = dhGroupExchangeMaximumBits
}
if kexDHGexRequest.PreferedBits < dhGroupExchangeMinimumBits {
kexDHGexRequest.PreferedBits = dhGroupExchangeMinimumBits
}
// fix min/max if they're inconsistent. technically, we could just pout
// and hang up, but there's no harm in giving them the benefit of the
// doubt and just picking a bitsize for them.
if kexDHGexRequest.MinBits > kexDHGexRequest.PreferedBits {
kexDHGexRequest.MinBits = kexDHGexRequest.PreferedBits
}
if kexDHGexRequest.MaxBits < kexDHGexRequest.PreferedBits {
kexDHGexRequest.MaxBits = kexDHGexRequest.PreferedBits
}
// Send GexGroup
// This is the group called diffie-hellman-group14-sha1 in RFC
// 4253 and Oakley Group 14 in RFC 3526.
p, _ := new(big.Int).SetString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
gex.p = p
gex.g = big.NewInt(2)
g := big.NewInt(2)
kexDHGexGroup := kexDHGexGroupMsg{
P: gex.p,
G: gex.g,
msg := &kexDHGexGroupMsg{
P: p,
G: g,
}
if err := c.writePacket(Marshal(&kexDHGexGroup)); err != nil {
if err := c.writePacket(Marshal(msg)); err != nil {
return nil, err
}
@ -723,19 +715,19 @@ func (gex dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshake
return
}
var pHalf = &big.Int{}
pHalf.Rsh(gex.p, 1)
pHalf := new(big.Int).Rsh(p, 1)
y, err := rand.Int(randSource, pHalf)
if err != nil {
return
}
Y := new(big.Int).Exp(g, y, p)
Y := new(big.Int).Exp(gex.g, y, gex.p)
kInt, err := gex.diffieHellman(kexDHGexInit.X, y)
if err != nil {
return nil, err
pMinusOne := new(big.Int).Sub(p, bigOne)
if kexDHGexInit.X.Cmp(bigOne) <= 0 || kexDHGexInit.X.Cmp(pMinusOne) >= 0 {
return nil, errors.New("ssh: DH parameter out of bounds")
}
kInt := new(big.Int).Exp(kexDHGexInit.X, y, p)
hostKeyBytes := priv.PublicKey().Marshal()
@ -745,8 +737,8 @@ func (gex dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshake
binary.Write(h, binary.BigEndian, uint32(dhGroupExchangeMinimumBits))
binary.Write(h, binary.BigEndian, uint32(dhGroupExchangePreferredBits))
binary.Write(h, binary.BigEndian, uint32(dhGroupExchangeMaximumBits))
writeInt(h, gex.p)
writeInt(h, gex.g)
writeInt(h, p)
writeInt(h, g)
writeInt(h, kexDHGexInit.X)
writeInt(h, Y)
@ -758,7 +750,7 @@ func (gex dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshake
// H is already a hash, but the hostkey signing will apply its
// own key-specific hash algorithm.
sig, err := signAndMarshal(priv, randSource, H)
sig, err := signAndMarshal(priv, randSource, H, algo)
if err != nil {
return nil, err
}

View File

@ -30,8 +30,9 @@ import (
"golang.org/x/crypto/ssh/internal/bcrypt_pbkdf"
)
// These constants represent the algorithm names for key types supported by this
// package.
// Public key algorithms names. These values can appear in PublicKey.Type,
// ClientConfig.HostKeyAlgorithms, Signature.Format, or as AlgorithmSigner
// arguments.
const (
KeyAlgoRSA = "ssh-rsa"
KeyAlgoDSA = "ssh-dss"
@ -41,16 +42,21 @@ const (
KeyAlgoECDSA521 = "ecdsa-sha2-nistp521"
KeyAlgoED25519 = "ssh-ed25519"
KeyAlgoSKED25519 = "sk-ssh-ed25519@openssh.com"
// KeyAlgoRSASHA256 and KeyAlgoRSASHA512 are only public key algorithms, not
// public key formats, so they can't appear as a PublicKey.Type. The
// corresponding PublicKey.Type is KeyAlgoRSA. See RFC 8332, Section 2.
KeyAlgoRSASHA256 = "rsa-sha2-256"
KeyAlgoRSASHA512 = "rsa-sha2-512"
)
// These constants represent non-default signature algorithms that are supported
// as algorithm parameters to AlgorithmSigner.SignWithAlgorithm methods. See
// [PROTOCOL.agent] section 4.5.1 and
// https://tools.ietf.org/html/draft-ietf-curdle-rsa-sha2-10
const (
SigAlgoRSA = "ssh-rsa"
SigAlgoRSASHA2256 = "rsa-sha2-256"
SigAlgoRSASHA2512 = "rsa-sha2-512"
// Deprecated: use KeyAlgoRSA.
SigAlgoRSA = KeyAlgoRSA
// Deprecated: use KeyAlgoRSASHA256.
SigAlgoRSASHA2256 = KeyAlgoRSASHA256
// Deprecated: use KeyAlgoRSASHA512.
SigAlgoRSASHA2512 = KeyAlgoRSASHA512
)
// parsePubKey parses a public key of the given algorithm.
@ -70,7 +76,7 @@ func parsePubKey(in []byte, algo string) (pubKey PublicKey, rest []byte, err err
case KeyAlgoSKED25519:
return parseSKEd25519(in)
case CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01, CertAlgoECDSA384v01, CertAlgoECDSA521v01, CertAlgoSKECDSA256v01, CertAlgoED25519v01, CertAlgoSKED25519v01:
cert, err := parseCert(in, certToPrivAlgo(algo))
cert, err := parseCert(in, certKeyAlgoNames[algo])
if err != nil {
return nil, nil, err
}
@ -289,18 +295,21 @@ func MarshalAuthorizedKey(key PublicKey) []byte {
return b.Bytes()
}
// PublicKey is an abstraction of different types of public keys.
// PublicKey represents a public key using an unspecified algorithm.
//
// Some PublicKeys provided by this package also implement CryptoPublicKey.
type PublicKey interface {
// Type returns the key's type, e.g. "ssh-rsa".
// Type returns the key format name, e.g. "ssh-rsa".
Type() string
// Marshal returns the serialized key data in SSH wire format,
// with the name prefix. To unmarshal the returned data, use
// the ParsePublicKey function.
// Marshal returns the serialized key data in SSH wire format, with the name
// prefix. To unmarshal the returned data, use the ParsePublicKey function.
Marshal() []byte
// Verify that sig is a signature on the given data using this
// key. This function will hash the data appropriately first.
// Verify that sig is a signature on the given data using this key. This
// method will hash the data appropriately first. sig.Format is allowed to
// be any signature algorithm compatible with the key type, the caller
// should check if it has more stringent requirements.
Verify(data []byte, sig *Signature) error
}
@ -311,25 +320,32 @@ type CryptoPublicKey interface {
}
// A Signer can create signatures that verify against a public key.
//
// Some Signers provided by this package also implement AlgorithmSigner.
type Signer interface {
// PublicKey returns an associated PublicKey instance.
// PublicKey returns the associated PublicKey.
PublicKey() PublicKey
// Sign returns raw signature for the given data. This method
// will apply the hash specified for the keytype to the data.
// Sign returns a signature for the given data. This method will hash the
// data appropriately first. The signature algorithm is expected to match
// the key format returned by the PublicKey.Type method (and not to be any
// alternative algorithm supported by the key format).
Sign(rand io.Reader, data []byte) (*Signature, error)
}
// A AlgorithmSigner is a Signer that also supports specifying a specific
// algorithm to use for signing.
// An AlgorithmSigner is a Signer that also supports specifying an algorithm to
// use for signing.
//
// An AlgorithmSigner can't advertise the algorithms it supports, so it should
// be prepared to be invoked with every algorithm supported by the public key
// format.
type AlgorithmSigner interface {
Signer
// SignWithAlgorithm is like Signer.Sign, but allows specification of a
// non-default signing algorithm. See the SigAlgo* constants in this
// package for signature algorithms supported by this package. Callers may
// pass an empty string for the algorithm in which case the AlgorithmSigner
// will use its default algorithm.
// SignWithAlgorithm is like Signer.Sign, but allows specifying a desired
// signing algorithm. Callers may pass an empty string for the algorithm in
// which case the AlgorithmSigner will use a default algorithm. This default
// doesn't currently control any behavior in this package.
SignWithAlgorithm(rand io.Reader, data []byte, algorithm string) (*Signature, error)
}
@ -381,17 +397,11 @@ func (r *rsaPublicKey) Marshal() []byte {
}
func (r *rsaPublicKey) Verify(data []byte, sig *Signature) error {
var hash crypto.Hash
switch sig.Format {
case SigAlgoRSA:
hash = crypto.SHA1
case SigAlgoRSASHA2256:
hash = crypto.SHA256
case SigAlgoRSASHA2512:
hash = crypto.SHA512
default:
supportedAlgos := algorithmsForKeyFormat(r.Type())
if !contains(supportedAlgos, sig.Format) {
return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, r.Type())
}
hash := hashFuncs[sig.Format]
h := hash.New()
h.Write(data)
digest := h.Sum(nil)
@ -466,7 +476,7 @@ func (k *dsaPublicKey) Verify(data []byte, sig *Signature) error {
if sig.Format != k.Type() {
return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, k.Type())
}
h := crypto.SHA1.New()
h := hashFuncs[sig.Format].New()
h.Write(data)
digest := h.Sum(nil)
@ -499,7 +509,7 @@ func (k *dsaPrivateKey) PublicKey() PublicKey {
}
func (k *dsaPrivateKey) Sign(rand io.Reader, data []byte) (*Signature, error) {
return k.SignWithAlgorithm(rand, data, "")
return k.SignWithAlgorithm(rand, data, k.PublicKey().Type())
}
func (k *dsaPrivateKey) SignWithAlgorithm(rand io.Reader, data []byte, algorithm string) (*Signature, error) {
@ -507,7 +517,7 @@ func (k *dsaPrivateKey) SignWithAlgorithm(rand io.Reader, data []byte, algorithm
return nil, fmt.Errorf("ssh: unsupported signature algorithm %s", algorithm)
}
h := crypto.SHA1.New()
h := hashFuncs[k.PublicKey().Type()].New()
h.Write(data)
digest := h.Sum(nil)
r, s, err := dsa.Sign(rand, k.PrivateKey, digest)
@ -603,19 +613,6 @@ func supportedEllipticCurve(curve elliptic.Curve) bool {
return curve == elliptic.P256() || curve == elliptic.P384() || curve == elliptic.P521()
}
// ecHash returns the hash to match the given elliptic curve, see RFC
// 5656, section 6.2.1
func ecHash(curve elliptic.Curve) crypto.Hash {
bitSize := curve.Params().BitSize
switch {
case bitSize <= 256:
return crypto.SHA256
case bitSize <= 384:
return crypto.SHA384
}
return crypto.SHA512
}
// parseECDSA parses an ECDSA key according to RFC 5656, section 3.1.
func parseECDSA(in []byte) (out PublicKey, rest []byte, err error) {
var w struct {
@ -671,7 +668,7 @@ func (k *ecdsaPublicKey) Verify(data []byte, sig *Signature) error {
return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, k.Type())
}
h := ecHash(k.Curve).New()
h := hashFuncs[sig.Format].New()
h.Write(data)
digest := h.Sum(nil)
@ -775,7 +772,7 @@ func (k *skECDSAPublicKey) Verify(data []byte, sig *Signature) error {
return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, k.Type())
}
h := ecHash(k.Curve).New()
h := hashFuncs[sig.Format].New()
h.Write([]byte(k.application))
appDigest := h.Sum(nil)
@ -874,7 +871,7 @@ func (k *skEd25519PublicKey) Verify(data []byte, sig *Signature) error {
return fmt.Errorf("invalid size %d for Ed25519 public key", l)
}
h := sha256.New()
h := hashFuncs[sig.Format].New()
h.Write([]byte(k.application))
appDigest := h.Sum(nil)
@ -961,44 +958,20 @@ func (s *wrappedSigner) PublicKey() PublicKey {
}
func (s *wrappedSigner) Sign(rand io.Reader, data []byte) (*Signature, error) {
return s.SignWithAlgorithm(rand, data, "")
return s.SignWithAlgorithm(rand, data, s.pubKey.Type())
}
func (s *wrappedSigner) SignWithAlgorithm(rand io.Reader, data []byte, algorithm string) (*Signature, error) {
var hashFunc crypto.Hash
if _, ok := s.pubKey.(*rsaPublicKey); ok {
// RSA keys support a few hash functions determined by the requested signature algorithm
switch algorithm {
case "", SigAlgoRSA:
algorithm = SigAlgoRSA
hashFunc = crypto.SHA1
case SigAlgoRSASHA2256:
hashFunc = crypto.SHA256
case SigAlgoRSASHA2512:
hashFunc = crypto.SHA512
default:
return nil, fmt.Errorf("ssh: unsupported signature algorithm %s", algorithm)
}
} else {
// The only supported algorithm for all other key types is the same as the type of the key
if algorithm == "" {
algorithm = s.pubKey.Type()
} else if algorithm != s.pubKey.Type() {
return nil, fmt.Errorf("ssh: unsupported signature algorithm %s", algorithm)
}
switch key := s.pubKey.(type) {
case *dsaPublicKey:
hashFunc = crypto.SHA1
case *ecdsaPublicKey:
hashFunc = ecHash(key.Curve)
case ed25519PublicKey:
default:
return nil, fmt.Errorf("ssh: unsupported key type %T", key)
}
supportedAlgos := algorithmsForKeyFormat(s.pubKey.Type())
if !contains(supportedAlgos, algorithm) {
return nil, fmt.Errorf("ssh: unsupported signature algorithm %q for key format %q", algorithm, s.pubKey.Type())
}
hashFunc := hashFuncs[algorithm]
var digest []byte
if hashFunc != 0 {
h := hashFunc.New()

View File

@ -141,6 +141,14 @@ type serviceAcceptMsg struct {
Service string `sshtype:"6"`
}
// See RFC 8308, section 2.3
const msgExtInfo = 7
type extInfoMsg struct {
NumExtensions uint32 `sshtype:"7"`
Payload []byte `ssh:"rest"`
}
// See RFC 4252, section 5.
const msgUserAuthRequest = 50
@ -180,9 +188,9 @@ const msgUserAuthInfoRequest = 60
const msgUserAuthInfoResponse = 61
type userAuthInfoRequestMsg struct {
User string `sshtype:"60"`
Name string `sshtype:"60"`
Instruction string
DeprecatedLanguage string
Language string
NumPrompts uint32
Prompts []byte `ssh:"rest"`
}
@ -782,6 +790,8 @@ func decode(packet []byte) (interface{}, error) {
msg = new(serviceRequestMsg)
case msgServiceAccept:
msg = new(serviceAcceptMsg)
case msgExtInfo:
msg = new(extInfoMsg)
case msgKexInit:
msg = new(kexInitMsg)
case msgKexDHInit:
@ -843,6 +853,7 @@ var packetTypeNames = map[byte]string{
msgDisconnect: "disconnectMsg",
msgServiceRequest: "serviceRequestMsg",
msgServiceAccept: "serviceAcceptMsg",
msgExtInfo: "extInfoMsg",
msgKexInit: "kexInitMsg",
msgKexDHInit: "kexDHInitMsg",
msgKexDHReply: "kexDHReplyMsg",

View File

@ -120,7 +120,7 @@ type ServerConfig struct {
}
// AddHostKey adds a private key as a host key. If an existing host
// key exists with the same algorithm, it is overwritten. Each server
// key exists with the same public key format, it is replaced. Each server
// config must have at least one host key.
func (s *ServerConfig) AddHostKey(key Signer) {
for i, k := range s.hostKeys {
@ -212,9 +212,10 @@ func NewServerConn(c net.Conn, config *ServerConfig) (*ServerConn, <-chan NewCha
}
// signAndMarshal signs the data with the appropriate algorithm,
// and serializes the result in SSH wire format.
func signAndMarshal(k Signer, rand io.Reader, data []byte) ([]byte, error) {
sig, err := k.Sign(rand, data)
// and serializes the result in SSH wire format. algo is the negotiate
// algorithm and may be a certificate type.
func signAndMarshal(k AlgorithmSigner, rand io.Reader, data []byte, algo string) ([]byte, error) {
sig, err := k.SignWithAlgorithm(rand, data, underlyingAlgo(algo))
if err != nil {
return nil, err
}
@ -284,7 +285,7 @@ func (s *connection) serverHandshake(config *ServerConfig) (*Permissions, error)
func isAcceptableAlgo(algo string) bool {
switch algo {
case KeyAlgoRSA, KeyAlgoDSA, KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521, KeyAlgoSKECDSA256, KeyAlgoED25519, KeyAlgoSKED25519,
case KeyAlgoRSA, KeyAlgoRSASHA256, KeyAlgoRSASHA512, KeyAlgoDSA, KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521, KeyAlgoSKECDSA256, KeyAlgoED25519, KeyAlgoSKED25519,
CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01, CertAlgoECDSA384v01, CertAlgoECDSA521v01, CertAlgoSKECDSA256v01, CertAlgoED25519v01, CertAlgoSKED25519v01:
return true
}
@ -553,6 +554,7 @@ userAuthLoop:
if !ok || len(payload) > 0 {
return nil, parseError(msgUserAuthRequest)
}
// Ensure the public key algo and signature algo
// are supported. Compare the private key
// algorithm name that corresponds to algo with
@ -562,7 +564,12 @@ userAuthLoop:
authErr = fmt.Errorf("ssh: algorithm %q not accepted", sig.Format)
break
}
signedData := buildDataSignedForAuth(sessionID, userAuthReq, algoBytes, pubKeyData)
if underlyingAlgo(algo) != sig.Format {
authErr = fmt.Errorf("ssh: signature %q not compatible with selected algorithm %q", sig.Format, algo)
break
}
signedData := buildDataSignedForAuth(sessionID, userAuthReq, algo, pubKeyData)
if err := pubKey.Verify(signedData, sig); err != nil {
return nil, err
@ -633,6 +640,30 @@ userAuthLoop:
}
authFailures++
if config.MaxAuthTries > 0 && authFailures >= config.MaxAuthTries {
// If we have hit the max attempts, don't bother sending the
// final SSH_MSG_USERAUTH_FAILURE message, since there are
// no more authentication methods which can be attempted,
// and this message may cause the client to re-attempt
// authentication while we send the disconnect message.
// Continue, and trigger the disconnect at the start of
// the loop.
//
// The SSH specification is somewhat confusing about this,
// RFC 4252 Section 5.1 requires each authentication failure
// be responded to with a respective SSH_MSG_USERAUTH_FAILURE
// message, but Section 4 says the server should disconnect
// after some number of attempts, but it isn't explicit which
// message should take precedence (i.e. should there be a failure
// message than a disconnect message, or if we are going to
// disconnect, should we only send that message.)
//
// Either way, OpenSSH disconnects immediately after the last
// failed authnetication attempt, and given they are typically
// considered the golden implementation it seems reasonable
// to match that behavior.
continue
}
var failureMsg userAuthFailureMsg
if config.PasswordCallback != nil {
@ -670,7 +701,7 @@ type sshClientKeyboardInteractive struct {
*connection
}
func (c *sshClientKeyboardInteractive) Challenge(user, instruction string, questions []string, echos []bool) (answers []string, err error) {
func (c *sshClientKeyboardInteractive) Challenge(name, instruction string, questions []string, echos []bool) (answers []string, err error) {
if len(questions) != len(echos) {
return nil, errors.New("ssh: echos and questions must have equal length")
}
@ -682,6 +713,7 @@ func (c *sshClientKeyboardInteractive) Challenge(user, instruction string, quest
}
if err := c.transport.writePacket(Marshal(&userAuthInfoRequestMsg{
Name: name,
Instruction: instruction,
NumPrompts: uint32(len(questions)),
Prompts: prompts,

View File

@ -85,6 +85,7 @@ const (
IXANY = 39
IXOFF = 40
IMAXBEL = 41
IUTF8 = 42 // RFC 8160
ISIG = 50
ICANON = 51
XCASE = 52

View File

@ -238,15 +238,19 @@ var (
// (to setup server->client keys) or clientKeys (for client->server keys).
func newPacketCipher(d direction, algs directionAlgorithms, kex *kexResult) (packetCipher, error) {
cipherMode := cipherModes[algs.Cipher]
macMode := macModes[algs.MAC]
iv := make([]byte, cipherMode.ivSize)
key := make([]byte, cipherMode.keySize)
macKey := make([]byte, macMode.keySize)
generateKeyMaterial(iv, d.ivTag, kex)
generateKeyMaterial(key, d.keyTag, kex)
var macKey []byte
if !aeadCiphers[algs.Cipher] {
macMode := macModes[algs.MAC]
macKey = make([]byte, macMode.keySize)
generateKeyMaterial(macKey, d.macKeyTag, kex)
}
return cipherModes[algs.Cipher].create(key, iv, macKey, algs)
}

3
vendor/modules.txt vendored
View File

@ -384,7 +384,7 @@ go.opentelemetry.io/proto/otlp/trace/v1
go.uber.org/automaxprocs/internal/cgroups
go.uber.org/automaxprocs/internal/runtime
go.uber.org/automaxprocs/maxprocs
# golang.org/x/crypto v0.0.0-20210921155107-089bfa567519
# golang.org/x/crypto v0.0.0-20220427172511-eb4f295cb31f
## explicit; go 1.17
golang.org/x/crypto/blake2b
golang.org/x/crypto/blowfish
@ -395,7 +395,6 @@ golang.org/x/crypto/cryptobyte/asn1
golang.org/x/crypto/curve25519
golang.org/x/crypto/curve25519/internal/field
golang.org/x/crypto/ed25519
golang.org/x/crypto/ed25519/internal/edwards25519
golang.org/x/crypto/hkdf
golang.org/x/crypto/internal/poly1305
golang.org/x/crypto/internal/subtle