Update dependencies and build to go1.22 (#2113)

* Update dependencies and build to go1.22

* Fix api changes wrt to dependencies

* Update golangci config
This commit is contained in:
Wim
2024-05-23 23:44:31 +02:00
committed by GitHub
parent 56e7bd01ca
commit 2f33fe86f5
1556 changed files with 3279522 additions and 1924375 deletions

View File

@@ -16,8 +16,9 @@ import (
// 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.
// Unlike key algorithm names, these are not passed to AlgorithmSigner nor
// returned by MultiAlgorithmSigner and don't appear in the Signature.Format
// field.
const (
CertAlgoRSAv01 = "ssh-rsa-cert-v01@openssh.com"
CertAlgoDSAv01 = "ssh-dss-cert-v01@openssh.com"
@@ -255,10 +256,17 @@ func NewCertSigner(cert *Certificate, signer Signer) (Signer, error) {
return nil, errors.New("ssh: signer and cert have different public key")
}
if algorithmSigner, ok := signer.(AlgorithmSigner); ok {
switch s := signer.(type) {
case MultiAlgorithmSigner:
return &multiAlgorithmSigner{
AlgorithmSigner: &algorithmOpenSSHCertSigner{
&openSSHCertSigner{cert, signer}, s},
supportedAlgorithms: s.Algorithms(),
}, nil
case AlgorithmSigner:
return &algorithmOpenSSHCertSigner{
&openSSHCertSigner{cert, signer}, algorithmSigner}, nil
} else {
&openSSHCertSigner{cert, signer}, s}, nil
default:
return &openSSHCertSigner{cert, signer}, nil
}
}
@@ -432,7 +440,9 @@ func (c *CertChecker) CheckCert(principal string, cert *Certificate) error {
}
// SignCert signs the certificate with an authority, setting the Nonce,
// SignatureKey, and Signature fields.
// SignatureKey, and Signature fields. If the authority implements the
// MultiAlgorithmSigner interface the first algorithm in the list is used. This
// is useful if you want to sign with a specific algorithm.
func (c *Certificate) SignCert(rand io.Reader, authority Signer) error {
c.Nonce = make([]byte, 32)
if _, err := io.ReadFull(rand, c.Nonce); err != nil {
@@ -440,8 +450,20 @@ 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 {
if v, ok := authority.(MultiAlgorithmSigner); ok {
if len(v.Algorithms()) == 0 {
return errors.New("the provided authority has no signature algorithm")
}
// Use the first algorithm in the list.
sig, err := v.SignWithAlgorithm(rand, c.bytesForSigning(), v.Algorithms()[0])
if err != nil {
return err
}
c.Signature = sig
return nil
} else if v, ok := authority.(AlgorithmSigner); ok && v.PublicKey().Type() == KeyAlgoRSA {
// Default to KeyAlgoRSASHA512 for ssh-rsa signers.
// TODO: consider using KeyAlgoRSASHA256 as default.
sig, err := v.SignWithAlgorithm(rand, c.bytesForSigning(), KeyAlgoRSASHA512)
if err != nil {
return err

View File

@@ -187,9 +187,11 @@ type channel struct {
pending *buffer
extPending *buffer
// windowMu protects myWindow, the flow-control window.
windowMu sync.Mutex
myWindow uint32
// windowMu protects myWindow, the flow-control window, and myConsumed,
// the number of bytes consumed since we last increased myWindow
windowMu sync.Mutex
myWindow uint32
myConsumed uint32
// writeMu serializes calls to mux.conn.writePacket() and
// protects sentClose and packetPool. This mutex must be
@@ -332,14 +334,24 @@ func (ch *channel) handleData(packet []byte) error {
return nil
}
func (c *channel) adjustWindow(n uint32) error {
func (c *channel) adjustWindow(adj uint32) error {
c.windowMu.Lock()
// Since myWindow is managed on our side, and can never exceed
// the initial window setting, we don't worry about overflow.
c.myWindow += uint32(n)
// Since myConsumed and myWindow are managed on our side, and can never
// exceed the initial window setting, we don't worry about overflow.
c.myConsumed += adj
var sendAdj uint32
if (channelWindowSize-c.myWindow > 3*c.maxIncomingPayload) ||
(c.myWindow < channelWindowSize/2) {
sendAdj = c.myConsumed
c.myConsumed = 0
c.myWindow += sendAdj
}
c.windowMu.Unlock()
if sendAdj == 0 {
return nil
}
return c.sendMessage(windowAdjustMsg{
AdditionalBytes: uint32(n),
AdditionalBytes: sendAdj,
})
}

View File

@@ -82,7 +82,7 @@ func NewClientConn(c net.Conn, addr string, config *ClientConfig) (Conn, <-chan
if err := conn.clientHandshake(addr, &fullConf); err != nil {
c.Close()
return nil, nil, nil, fmt.Errorf("ssh: handshake failed: %v", err)
return nil, nil, nil, fmt.Errorf("ssh: handshake failed: %w", err)
}
conn.mux = newMux(conn.transport)
return conn, conn.mux.incomingChannels, conn.mux.incomingRequests, nil

View File

@@ -71,7 +71,9 @@ func (c *connection) clientAuthenticate(config *ClientConfig) error {
for auth := AuthMethod(new(noneAuth)); auth != nil; {
ok, methods, err := auth.auth(sessionID, config.User, c.transport, config.Rand, extensions)
if err != nil {
return err
// We return the error later if there is no other method left to
// try.
ok = authFailure
}
if ok == authSuccess {
// success
@@ -101,6 +103,12 @@ func (c *connection) clientAuthenticate(config *ClientConfig) error {
}
}
}
if auth == nil && err != nil {
// We have an error and there are no other authentication methods to
// try, so we return it.
return err
}
}
return fmt.Errorf("ssh: unable to authenticate, attempted methods %v, no supported methods remain", tried)
}
@@ -217,21 +225,45 @@ func (cb publicKeyCallback) method() string {
return "publickey"
}
func pickSignatureAlgorithm(signer Signer, extensions map[string][]byte) (as AlgorithmSigner, algo string) {
func pickSignatureAlgorithm(signer Signer, extensions map[string][]byte) (MultiAlgorithmSigner, string, error) {
var as MultiAlgorithmSigner
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
// If the signer implements MultiAlgorithmSigner we use the algorithms it
// support, if it implements AlgorithmSigner we assume it supports all
// algorithms, otherwise only the key format one.
switch s := signer.(type) {
case MultiAlgorithmSigner:
as = s
case AlgorithmSigner:
as = &multiAlgorithmSigner{
AlgorithmSigner: s,
supportedAlgorithms: algorithmsForKeyFormat(underlyingAlgo(keyFormat)),
}
default:
as = &multiAlgorithmSigner{
AlgorithmSigner: algorithmSignerWrapper{signer},
supportedAlgorithms: []string{underlyingAlgo(keyFormat)},
}
}
getFallbackAlgo := func() (string, error) {
// Fallback to use if there is no "server-sig-algs" extension or a
// common algorithm cannot be found. We use the public key format if the
// MultiAlgorithmSigner supports it, otherwise we return an error.
if !contains(as.Algorithms(), underlyingAlgo(keyFormat)) {
return "", fmt.Errorf("ssh: no common public key signature algorithm, server only supports %q for key type %q, signer only supports %v",
underlyingAlgo(keyFormat), keyFormat, as.Algorithms())
}
return keyFormat, nil
}
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
// If there is no "server-sig-algs" extension use the fallback
// algorithm.
algo, err := getFallbackAlgo()
return as, algo, err
}
// The server-sig-algs extension only carries underlying signature
@@ -245,15 +277,22 @@ func pickSignatureAlgorithm(signer Signer, extensions map[string][]byte) (as Alg
}
}
keyAlgos := algorithmsForKeyFormat(keyFormat)
// Filter algorithms based on those supported by MultiAlgorithmSigner.
var keyAlgos []string
for _, algo := range algorithmsForKeyFormat(keyFormat) {
if contains(as.Algorithms(), underlyingAlgo(algo)) {
keyAlgos = append(keyAlgos, algo)
}
}
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
// If there is no overlap, return the fallback algorithm to support
// servers that fail to list all supported algorithms.
algo, err := getFallbackAlgo()
return as, algo, err
}
return as, algo
return as, algo, nil
}
func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand io.Reader, extensions map[string][]byte) (authResult, []string, error) {
@@ -267,14 +306,39 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
return authFailure, nil, err
}
var methods []string
for _, signer := range signers {
pub := signer.PublicKey()
as, algo := pickSignatureAlgorithm(signer, extensions)
var errSigAlgo error
origSignersLen := len(signers)
for idx := 0; idx < len(signers); idx++ {
signer := signers[idx]
pub := signer.PublicKey()
as, algo, err := pickSignatureAlgorithm(signer, extensions)
if err != nil && errSigAlgo == nil {
// If we cannot negotiate a signature algorithm store the first
// error so we can return it to provide a more meaningful message if
// no other signers work.
errSigAlgo = err
continue
}
ok, err := validateKey(pub, algo, user, c)
if err != nil {
return authFailure, nil, err
}
// OpenSSH 7.2-7.7 advertises support for rsa-sha2-256 and rsa-sha2-512
// in the "server-sig-algs" extension but doesn't support these
// algorithms for certificate authentication, so if the server rejects
// the key try to use the obtained algorithm as if "server-sig-algs" had
// not been implemented if supported from the algorithm signer.
if !ok && idx < origSignersLen && isRSACert(algo) && algo != CertAlgoRSAv01 {
if contains(as.Algorithms(), KeyAlgoRSA) {
// We retry using the compat algorithm after all signers have
// been tried normally.
signers = append(signers, &multiAlgorithmSigner{
AlgorithmSigner: as,
supportedAlgorithms: []string{KeyAlgoRSA},
})
}
}
if !ok {
continue
}
@@ -317,22 +381,12 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
// 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 == authSuccess || !containsMethod(methods, cb.method()) {
if success == authSuccess || !contains(methods, cb.method()) {
return success, methods, err
}
}
return authFailure, methods, nil
}
func containsMethod(methods []string, method string) bool {
for _, m := range methods {
if m == method {
return true
}
}
return false
return authFailure, methods, errSigAlgo
}
// validateKey validates the key provided is acceptable to the server.
@@ -350,10 +404,10 @@ func validateKey(key PublicKey, algo string, user string, c packetConn) (bool, e
return false, err
}
return confirmKeyAck(key, algo, c)
return confirmKeyAck(key, c)
}
func confirmKeyAck(key PublicKey, algo string, c packetConn) (bool, error) {
func confirmKeyAck(key PublicKey, c packetConn) (bool, error) {
pubKey := key.Marshal()
for {
@@ -371,7 +425,15 @@ func confirmKeyAck(key PublicKey, algo string, c packetConn) (bool, error) {
if err := Unmarshal(packet, &msg); err != nil {
return false, err
}
if msg.Algo != algo || !bytes.Equal(msg.PubKey, pubKey) {
// According to RFC 4252 Section 7 the algorithm in
// SSH_MSG_USERAUTH_PK_OK should match that of the request but some
// servers send the key type instead. OpenSSH allows any algorithm
// that matches the public key, so we do the same.
// https://github.com/openssh/openssh-portable/blob/86bdd385/sshconnect2.c#L709
if !contains(algorithmsForKeyFormat(key.Type()), msg.Algo) {
return false, nil
}
if !bytes.Equal(msg.PubKey, pubKey) {
return false, nil
}
return true, nil

View File

@@ -10,7 +10,6 @@ import (
"fmt"
"io"
"math"
"strings"
"sync"
_ "crypto/sha1"
@@ -128,6 +127,14 @@ func isRSA(algo string) bool {
return contains(algos, underlyingAlgo(algo))
}
func isRSACert(algo string) bool {
_, ok := certKeyAlgoNames[algo]
if !ok {
return false
}
return isRSA(algo)
}
// supportedPubKeyAuthAlgos specifies the supported client public key
// authentication algorithms. Note that this doesn't include certificate types
// since those use the underlying algorithm. This list is sent to the client if
@@ -140,8 +147,6 @@ var supportedPubKeyAuthAlgos = []string{
KeyAlgoDSA,
}
var supportedPubKeyAuthAlgosList = strings.Join(supportedPubKeyAuthAlgos, ",")
// unexpectedMessageError results when the SSH message that we received didn't
// match what we wanted.
func unexpectedMessageError(expected, got uint8) error {

View File

@@ -13,6 +13,7 @@ others.
References:
[PROTOCOL]: https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/PROTOCOL?rev=HEAD
[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

@@ -11,6 +11,7 @@ import (
"io"
"log"
"net"
"strings"
"sync"
)
@@ -34,6 +35,16 @@ type keyingTransport interface {
// direction will be effected if a msgNewKeys message is sent
// or received.
prepareKeyChange(*algorithms, *kexResult) error
// setStrictMode sets the strict KEX mode, notably triggering
// sequence number resets on sending or receiving msgNewKeys.
// If the sequence number is already > 1 when setStrictMode
// is called, an error is returned.
setStrictMode() error
// setInitialKEXDone indicates to the transport that the initial key exchange
// was completed
setInitialKEXDone()
}
// handshakeTransport implements rekeying on top of a keyingTransport
@@ -50,6 +61,10 @@ type handshakeTransport struct {
// connection.
hostKeys []Signer
// publicKeyAuthAlgorithms is non-empty if we are the server. In that case,
// it contains the supported client public key authentication algorithms.
publicKeyAuthAlgorithms []string
// hostKeyAlgorithms is non-empty if we are the client. In that case,
// we accept these key types from the server as host key.
hostKeyAlgorithms []string
@@ -95,6 +110,10 @@ type handshakeTransport struct {
// The session ID or nil if first kex did not complete yet.
sessionID []byte
// strictMode indicates if the other side of the handshake indicated
// that we should be following the strict KEX protocol restrictions.
strictMode bool
}
type pendingKex struct {
@@ -141,6 +160,7 @@ func newClientTransport(conn keyingTransport, clientVersion, serverVersion []byt
func newServerTransport(conn keyingTransport, clientVersion, serverVersion []byte, config *ServerConfig) *handshakeTransport {
t := newHandshakeTransport(conn, &config.Config, clientVersion, serverVersion)
t.hostKeys = config.hostKeys
t.publicKeyAuthAlgorithms = config.PublicKeyAuthAlgorithms
go t.readLoop()
go t.kexLoop()
return t
@@ -203,7 +223,10 @@ func (t *handshakeTransport) readLoop() {
close(t.incoming)
break
}
if p[0] == msgIgnore || p[0] == msgDebug {
// If this is the first kex, and strict KEX mode is enabled,
// we don't ignore any messages, as they may be used to manipulate
// the packet sequence numbers.
if !(t.sessionID == nil && t.strictMode) && (p[0] == msgIgnore || p[0] == msgDebug) {
continue
}
t.incoming <- p
@@ -435,6 +458,11 @@ func (t *handshakeTransport) readOnePacket(first bool) ([]byte, error) {
return successPacket, nil
}
const (
kexStrictClient = "kex-strict-c-v00@openssh.com"
kexStrictServer = "kex-strict-s-v00@openssh.com"
)
// sendKexInit sends a key change message.
func (t *handshakeTransport) sendKexInit() error {
t.mu.Lock()
@@ -448,7 +476,6 @@ func (t *handshakeTransport) sendKexInit() error {
}
msg := &kexInitMsg{
KexAlgos: t.config.KeyExchanges,
CiphersClientServer: t.config.Ciphers,
CiphersServerClient: t.config.Ciphers,
MACsClientServer: t.config.MACs,
@@ -458,36 +485,55 @@ func (t *handshakeTransport) sendKexInit() error {
}
io.ReadFull(rand.Reader, msg.Cookie[:])
// We mutate the KexAlgos slice, in order to add the kex-strict extension algorithm,
// and possibly to add the ext-info extension algorithm. Since the slice may be the
// user owned KeyExchanges, we create our own slice in order to avoid using user
// owned memory by mistake.
msg.KexAlgos = make([]string, 0, len(t.config.KeyExchanges)+2) // room for kex-strict and ext-info
msg.KexAlgos = append(msg.KexAlgos, t.config.KeyExchanges...)
isServer := len(t.hostKeys) > 0
if isServer {
for _, k := range t.hostKeys {
// 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.)
// If k is a MultiAlgorithmSigner, we restrict the signature
// algorithms. If k is a AlgorithmSigner, presume it supports all
// signature algorithms associated with the key format. 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 {
switch s := k.(type) {
case MultiAlgorithmSigner:
for _, algo := range algorithmsForKeyFormat(keyFormat) {
if contains(s.Algorithms(), underlyingAlgo(algo)) {
msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, algo)
}
}
case AlgorithmSigner:
msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, algorithmsForKeyFormat(keyFormat)...)
} else {
default:
msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, keyFormat)
}
}
if t.sessionID == nil {
msg.KexAlgos = append(msg.KexAlgos, kexStrictServer)
}
} 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.
//
// We also send the strict KEX mode extension algorithm, in order to opt
// into the strict KEX mode.
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")
msg.KexAlgos = append(msg.KexAlgos, kexStrictClient)
}
}
packet := Marshal(msg)
@@ -593,6 +639,13 @@ func (t *handshakeTransport) enterKeyExchange(otherInitPacket []byte) error {
return err
}
if t.sessionID == nil && ((isClient && contains(serverInit.KexAlgos, kexStrictServer)) || (!isClient && contains(clientInit.KexAlgos, kexStrictClient))) {
t.strictMode = true
if err := t.conn.setStrictMode(); err != nil {
return err
}
}
// We don't send FirstKexFollows, but we handle receiving it.
//
// RFC 4253 section 7 defines the kex and the agreement method for
@@ -642,16 +695,21 @@ func (t *handshakeTransport) enterKeyExchange(otherInitPacket []byte) error {
// On the server side, after the first SSH_MSG_NEWKEYS, send a SSH_MSG_EXT_INFO
// message with the server-sig-algs extension if the client supports it. See
// RFC 8308, Sections 2.4 and 3.1.
// RFC 8308, Sections 2.4 and 3.1, and [PROTOCOL], Section 1.9.
if !isClient && firstKeyExchange && contains(clientInit.KexAlgos, "ext-info-c") {
supportedPubKeyAuthAlgosList := strings.Join(t.publicKeyAuthAlgorithms, ",")
extInfo := &extInfoMsg{
NumExtensions: 1,
Payload: make([]byte, 0, 4+15+4+len(supportedPubKeyAuthAlgosList)),
NumExtensions: 2,
Payload: make([]byte, 0, 4+15+4+len(supportedPubKeyAuthAlgosList)+4+16+4+1),
}
extInfo.Payload = appendInt(extInfo.Payload, len("server-sig-algs"))
extInfo.Payload = append(extInfo.Payload, "server-sig-algs"...)
extInfo.Payload = appendInt(extInfo.Payload, len(supportedPubKeyAuthAlgosList))
extInfo.Payload = append(extInfo.Payload, supportedPubKeyAuthAlgosList...)
extInfo.Payload = appendInt(extInfo.Payload, len("ping@openssh.com"))
extInfo.Payload = append(extInfo.Payload, "ping@openssh.com"...)
extInfo.Payload = appendInt(extInfo.Payload, 1)
extInfo.Payload = append(extInfo.Payload, "0"...)
if err := t.conn.writePacket(Marshal(extInfo)); err != nil {
return err
}
@@ -663,6 +721,12 @@ func (t *handshakeTransport) enterKeyExchange(otherInitPacket []byte) error {
return unexpectedMessageError(msgNewKeys, packet[0])
}
if firstKeyExchange {
// Indicates to the transport that the first key exchange is completed
// after receiving SSH_MSG_NEWKEYS.
t.conn.setInitialKEXDone()
}
return nil
}
@@ -685,9 +749,16 @@ func (a algorithmSignerWrapper) SignWithAlgorithm(rand io.Reader, data []byte, a
func pickHostKey(hostKeys []Signer, algo string) AlgorithmSigner {
for _, k := range hostKeys {
if s, ok := k.(MultiAlgorithmSigner); ok {
if !contains(s.Algorithms(), underlyingAlgo(algo)) {
continue
}
}
if algo == k.PublicKey().Type() {
return algorithmSignerWrapper{k}
}
k, ok := k.(AlgorithmSigner)
if !ok {
continue

View File

@@ -11,13 +11,16 @@ import (
"crypto/cipher"
"crypto/dsa"
"crypto/ecdsa"
"crypto/ed25519"
"crypto/elliptic"
"crypto/md5"
"crypto/rand"
"crypto/rsa"
"crypto/sha256"
"crypto/x509"
"encoding/asn1"
"encoding/base64"
"encoding/binary"
"encoding/hex"
"encoding/pem"
"errors"
@@ -26,7 +29,6 @@ import (
"math/big"
"strings"
"golang.org/x/crypto/ed25519"
"golang.org/x/crypto/ssh/internal/bcrypt_pbkdf"
)
@@ -295,6 +297,18 @@ func MarshalAuthorizedKey(key PublicKey) []byte {
return b.Bytes()
}
// MarshalPrivateKey returns a PEM block with the private key serialized in the
// OpenSSH format.
func MarshalPrivateKey(key crypto.PrivateKey, comment string) (*pem.Block, error) {
return marshalOpenSSHPrivateKey(key, comment, unencryptedOpenSSHMarshaler)
}
// MarshalPrivateKeyWithPassphrase returns a PEM block holding the encrypted
// private key serialized in the OpenSSH format.
func MarshalPrivateKeyWithPassphrase(key crypto.PrivateKey, comment string, passphrase []byte) (*pem.Block, error) {
return marshalOpenSSHPrivateKey(key, comment, passphraseProtectedOpenSSHMarshaler(passphrase))
}
// PublicKey represents a public key using an unspecified algorithm.
//
// Some PublicKeys provided by this package also implement CryptoPublicKey.
@@ -321,7 +335,7 @@ type CryptoPublicKey interface {
// A Signer can create signatures that verify against a public key.
//
// Some Signers provided by this package also implement AlgorithmSigner.
// Some Signers provided by this package also implement MultiAlgorithmSigner.
type Signer interface {
// PublicKey returns the associated PublicKey.
PublicKey() PublicKey
@@ -336,9 +350,9 @@ type Signer interface {
// 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.
// An AlgorithmSigner can't advertise the algorithms it supports, unless it also
// implements MultiAlgorithmSigner, so it should be prepared to be invoked with
// every algorithm supported by the public key format.
type AlgorithmSigner interface {
Signer
@@ -349,6 +363,75 @@ type AlgorithmSigner interface {
SignWithAlgorithm(rand io.Reader, data []byte, algorithm string) (*Signature, error)
}
// MultiAlgorithmSigner is an AlgorithmSigner that also reports the algorithms
// supported by that signer.
type MultiAlgorithmSigner interface {
AlgorithmSigner
// Algorithms returns the available algorithms in preference order. The list
// must not be empty, and it must not include certificate types.
Algorithms() []string
}
// NewSignerWithAlgorithms returns a signer restricted to the specified
// algorithms. The algorithms must be set in preference order. The list must not
// be empty, and it must not include certificate types. An error is returned if
// the specified algorithms are incompatible with the public key type.
func NewSignerWithAlgorithms(signer AlgorithmSigner, algorithms []string) (MultiAlgorithmSigner, error) {
if len(algorithms) == 0 {
return nil, errors.New("ssh: please specify at least one valid signing algorithm")
}
var signerAlgos []string
supportedAlgos := algorithmsForKeyFormat(underlyingAlgo(signer.PublicKey().Type()))
if s, ok := signer.(*multiAlgorithmSigner); ok {
signerAlgos = s.Algorithms()
} else {
signerAlgos = supportedAlgos
}
for _, algo := range algorithms {
if !contains(supportedAlgos, algo) {
return nil, fmt.Errorf("ssh: algorithm %q is not supported for key type %q",
algo, signer.PublicKey().Type())
}
if !contains(signerAlgos, algo) {
return nil, fmt.Errorf("ssh: algorithm %q is restricted for the provided signer", algo)
}
}
return &multiAlgorithmSigner{
AlgorithmSigner: signer,
supportedAlgorithms: algorithms,
}, nil
}
type multiAlgorithmSigner struct {
AlgorithmSigner
supportedAlgorithms []string
}
func (s *multiAlgorithmSigner) Algorithms() []string {
return s.supportedAlgorithms
}
func (s *multiAlgorithmSigner) isAlgorithmSupported(algorithm string) bool {
if algorithm == "" {
algorithm = underlyingAlgo(s.PublicKey().Type())
}
for _, algo := range s.supportedAlgorithms {
if algorithm == algo {
return true
}
}
return false
}
func (s *multiAlgorithmSigner) SignWithAlgorithm(rand io.Reader, data []byte, algorithm string) (*Signature, error) {
if !s.isAlgorithmSupported(algorithm) {
return nil, fmt.Errorf("ssh: algorithm %q is not supported: %v", algorithm, s.supportedAlgorithms)
}
return s.AlgorithmSigner.SignWithAlgorithm(rand, data, algorithm)
}
type rsaPublicKey rsa.PublicKey
func (r *rsaPublicKey) Type() string {
@@ -512,6 +595,10 @@ func (k *dsaPrivateKey) Sign(rand io.Reader, data []byte) (*Signature, error) {
return k.SignWithAlgorithm(rand, data, k.PublicKey().Type())
}
func (k *dsaPrivateKey) Algorithms() []string {
return []string{k.PublicKey().Type()}
}
func (k *dsaPrivateKey) SignWithAlgorithm(rand io.Reader, data []byte, algorithm string) (*Signature, error) {
if algorithm != "" && algorithm != k.PublicKey().Type() {
return nil, fmt.Errorf("ssh: unsupported signature algorithm %s", algorithm)
@@ -961,13 +1048,16 @@ func (s *wrappedSigner) Sign(rand io.Reader, data []byte) (*Signature, error) {
return s.SignWithAlgorithm(rand, data, s.pubKey.Type())
}
func (s *wrappedSigner) Algorithms() []string {
return algorithmsForKeyFormat(s.pubKey.Type())
}
func (s *wrappedSigner) SignWithAlgorithm(rand io.Reader, data []byte, algorithm string) (*Signature, error) {
if algorithm == "" {
algorithm = s.pubKey.Type()
}
supportedAlgos := algorithmsForKeyFormat(s.pubKey.Type())
if !contains(supportedAlgos, algorithm) {
if !contains(s.Algorithms(), algorithm) {
return nil, fmt.Errorf("ssh: unsupported signature algorithm %q for key format %q", algorithm, s.pubKey.Type())
}
@@ -1142,16 +1232,27 @@ func ParseRawPrivateKeyWithPassphrase(pemBytes, passphrase []byte) (interface{},
return nil, fmt.Errorf("ssh: cannot decode encrypted private keys: %v", err)
}
var result interface{}
switch block.Type {
case "RSA PRIVATE KEY":
return x509.ParsePKCS1PrivateKey(buf)
result, err = x509.ParsePKCS1PrivateKey(buf)
case "EC PRIVATE KEY":
return x509.ParseECPrivateKey(buf)
result, err = x509.ParseECPrivateKey(buf)
case "DSA PRIVATE KEY":
return ParseDSAPrivateKey(buf)
result, err = ParseDSAPrivateKey(buf)
default:
return nil, fmt.Errorf("ssh: unsupported key type %q", block.Type)
err = fmt.Errorf("ssh: unsupported key type %q", block.Type)
}
// Because of deficiencies in the format, DecryptPEMBlock does not always
// detect an incorrect password. In these cases decrypted DER bytes is
// random noise. If the parsing of the key returns an asn1.StructuralError
// we return x509.IncorrectPasswordError.
if _, ok := err.(asn1.StructuralError); ok {
return nil, x509.IncorrectPasswordError
}
return result, err
}
// ParseDSAPrivateKey returns a DSA private key from its ASN.1 DER encoding, as
@@ -1241,28 +1342,106 @@ func passphraseProtectedOpenSSHKey(passphrase []byte) openSSHDecryptFunc {
}
}
func unencryptedOpenSSHMarshaler(privKeyBlock []byte) ([]byte, string, string, string, error) {
key := generateOpenSSHPadding(privKeyBlock, 8)
return key, "none", "none", "", nil
}
func passphraseProtectedOpenSSHMarshaler(passphrase []byte) openSSHEncryptFunc {
return func(privKeyBlock []byte) ([]byte, string, string, string, error) {
salt := make([]byte, 16)
if _, err := rand.Read(salt); err != nil {
return nil, "", "", "", err
}
opts := struct {
Salt []byte
Rounds uint32
}{salt, 16}
// Derive key to encrypt the private key block.
k, err := bcrypt_pbkdf.Key(passphrase, salt, int(opts.Rounds), 32+aes.BlockSize)
if err != nil {
return nil, "", "", "", err
}
// Add padding matching the block size of AES.
keyBlock := generateOpenSSHPadding(privKeyBlock, aes.BlockSize)
// Encrypt the private key using the derived secret.
dst := make([]byte, len(keyBlock))
key, iv := k[:32], k[32:]
block, err := aes.NewCipher(key)
if err != nil {
return nil, "", "", "", err
}
stream := cipher.NewCTR(block, iv)
stream.XORKeyStream(dst, keyBlock)
return dst, "aes256-ctr", "bcrypt", string(Marshal(opts)), nil
}
}
const privateKeyAuthMagic = "openssh-key-v1\x00"
type openSSHDecryptFunc func(CipherName, KdfName, KdfOpts string, PrivKeyBlock []byte) ([]byte, error)
type openSSHEncryptFunc func(PrivKeyBlock []byte) (ProtectedKeyBlock []byte, cipherName, kdfName, kdfOptions string, err error)
type openSSHEncryptedPrivateKey struct {
CipherName string
KdfName string
KdfOpts string
NumKeys uint32
PubKey []byte
PrivKeyBlock []byte
}
type openSSHPrivateKey struct {
Check1 uint32
Check2 uint32
Keytype string
Rest []byte `ssh:"rest"`
}
type openSSHRSAPrivateKey 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"`
}
type openSSHEd25519PrivateKey struct {
Pub []byte
Priv []byte
Comment string
Pad []byte `ssh:"rest"`
}
type openSSHECDSAPrivateKey struct {
Curve string
Pub []byte
D *big.Int
Comment string
Pad []byte `ssh:"rest"`
}
// parseOpenSSHPrivateKey parses an OpenSSH private key, using the decrypt
// function to unwrap the encrypted portion. unencryptedOpenSSHKey can be used
// as the decrypt function to parse an unencrypted private key. See
// https://github.com/openssh/openssh-portable/blob/master/PROTOCOL.key.
func parseOpenSSHPrivateKey(key []byte, decrypt openSSHDecryptFunc) (crypto.PrivateKey, error) {
const magic = "openssh-key-v1\x00"
if len(key) < len(magic) || string(key[:len(magic)]) != magic {
if len(key) < len(privateKeyAuthMagic) || string(key[:len(privateKeyAuthMagic)]) != privateKeyAuthMagic {
return nil, errors.New("ssh: invalid openssh private key format")
}
remaining := key[len(magic):]
var w struct {
CipherName string
KdfName string
KdfOpts string
NumKeys uint32
PubKey []byte
PrivKeyBlock []byte
}
remaining := key[len(privateKeyAuthMagic):]
var w openSSHEncryptedPrivateKey
if err := Unmarshal(remaining, &w); err != nil {
return nil, err
}
@@ -1284,13 +1463,7 @@ func parseOpenSSHPrivateKey(key []byte, decrypt openSSHDecryptFunc) (crypto.Priv
return nil, err
}
pk1 := struct {
Check1 uint32
Check2 uint32
Keytype string
Rest []byte `ssh:"rest"`
}{}
var pk1 openSSHPrivateKey
if err := Unmarshal(privKeyBlock, &pk1); err != nil || pk1.Check1 != pk1.Check2 {
if w.CipherName != "none" {
return nil, x509.IncorrectPasswordError
@@ -1300,18 +1473,7 @@ func parseOpenSSHPrivateKey(key []byte, decrypt openSSHDecryptFunc) (crypto.Priv
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"`
}{}
var key openSSHRSAPrivateKey
if err := Unmarshal(pk1.Rest, &key); err != nil {
return nil, err
}
@@ -1337,13 +1499,7 @@ func parseOpenSSHPrivateKey(key []byte, decrypt openSSHDecryptFunc) (crypto.Priv
return pk, nil
case KeyAlgoED25519:
key := struct {
Pub []byte
Priv []byte
Comment string
Pad []byte `ssh:"rest"`
}{}
var key openSSHEd25519PrivateKey
if err := Unmarshal(pk1.Rest, &key); err != nil {
return nil, err
}
@@ -1360,14 +1516,7 @@ func parseOpenSSHPrivateKey(key []byte, decrypt openSSHDecryptFunc) (crypto.Priv
copy(pk, key.Priv)
return &pk, nil
case KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521:
key := struct {
Curve string
Pub []byte
D *big.Int
Comment string
Pad []byte `ssh:"rest"`
}{}
var key openSSHECDSAPrivateKey
if err := Unmarshal(pk1.Rest, &key); err != nil {
return nil, err
}
@@ -1415,6 +1564,131 @@ func parseOpenSSHPrivateKey(key []byte, decrypt openSSHDecryptFunc) (crypto.Priv
}
}
func marshalOpenSSHPrivateKey(key crypto.PrivateKey, comment string, encrypt openSSHEncryptFunc) (*pem.Block, error) {
var w openSSHEncryptedPrivateKey
var pk1 openSSHPrivateKey
// Random check bytes.
var check uint32
if err := binary.Read(rand.Reader, binary.BigEndian, &check); err != nil {
return nil, err
}
pk1.Check1 = check
pk1.Check2 = check
w.NumKeys = 1
// Use a []byte directly on ed25519 keys.
if k, ok := key.(*ed25519.PrivateKey); ok {
key = *k
}
switch k := key.(type) {
case *rsa.PrivateKey:
E := new(big.Int).SetInt64(int64(k.PublicKey.E))
// Marshal public key:
// E and N are in reversed order in the public and private key.
pubKey := struct {
KeyType string
E *big.Int
N *big.Int
}{
KeyAlgoRSA,
E, k.PublicKey.N,
}
w.PubKey = Marshal(pubKey)
// Marshal private key.
key := openSSHRSAPrivateKey{
N: k.PublicKey.N,
E: E,
D: k.D,
Iqmp: k.Precomputed.Qinv,
P: k.Primes[0],
Q: k.Primes[1],
Comment: comment,
}
pk1.Keytype = KeyAlgoRSA
pk1.Rest = Marshal(key)
case ed25519.PrivateKey:
pub := make([]byte, ed25519.PublicKeySize)
priv := make([]byte, ed25519.PrivateKeySize)
copy(pub, k[32:])
copy(priv, k)
// Marshal public key.
pubKey := struct {
KeyType string
Pub []byte
}{
KeyAlgoED25519, pub,
}
w.PubKey = Marshal(pubKey)
// Marshal private key.
key := openSSHEd25519PrivateKey{
Pub: pub,
Priv: priv,
Comment: comment,
}
pk1.Keytype = KeyAlgoED25519
pk1.Rest = Marshal(key)
case *ecdsa.PrivateKey:
var curve, keyType string
switch name := k.Curve.Params().Name; name {
case "P-256":
curve = "nistp256"
keyType = KeyAlgoECDSA256
case "P-384":
curve = "nistp384"
keyType = KeyAlgoECDSA384
case "P-521":
curve = "nistp521"
keyType = KeyAlgoECDSA521
default:
return nil, errors.New("ssh: unhandled elliptic curve " + name)
}
pub := elliptic.Marshal(k.Curve, k.PublicKey.X, k.PublicKey.Y)
// Marshal public key.
pubKey := struct {
KeyType string
Curve string
Pub []byte
}{
keyType, curve, pub,
}
w.PubKey = Marshal(pubKey)
// Marshal private key.
key := openSSHECDSAPrivateKey{
Curve: curve,
Pub: pub,
D: k.D,
Comment: comment,
}
pk1.Keytype = keyType
pk1.Rest = Marshal(key)
default:
return nil, fmt.Errorf("ssh: unsupported key type %T", k)
}
var err error
// Add padding and encrypt the key if necessary.
w.PrivKeyBlock, w.CipherName, w.KdfName, w.KdfOpts, err = encrypt(Marshal(pk1))
if err != nil {
return nil, err
}
b := Marshal(w)
block := &pem.Block{
Type: "OPENSSH PRIVATE KEY",
Bytes: append([]byte(privateKeyAuthMagic), b...),
}
return block, nil
}
func checkOpenSSHKeyPadding(pad []byte) error {
for i, b := range pad {
if int(b) != i+1 {
@@ -1424,6 +1698,13 @@ func checkOpenSSHKeyPadding(pad []byte) error {
return nil
}
func generateOpenSSHPadding(block []byte, blockSize int) []byte {
for i, l := 0, len(block); (l+i)%blockSize != 0; i++ {
block = append(block, byte(i+1))
}
return block
}
// FingerprintLegacyMD5 returns the user presentation of the key's
// fingerprint as described by RFC 4716 section 4.
func FingerprintLegacyMD5(pubKey PublicKey) string {

View File

@@ -349,6 +349,20 @@ type userAuthGSSAPIError struct {
LanguageTag string
}
// Transport layer OpenSSH extension. See [PROTOCOL], section 1.9
const msgPing = 192
type pingMsg struct {
Data string `sshtype:"192"`
}
// Transport layer OpenSSH extension. See [PROTOCOL], section 1.9
const msgPong = 193
type pongMsg struct {
Data string `sshtype:"193"`
}
// typeTags returns the possible type bytes for the given reflect.Type, which
// should be a struct. The possible values are separated by a '|' character.
func typeTags(structType reflect.Type) (tags []byte) {

View File

@@ -231,6 +231,12 @@ func (m *mux) onePacket() error {
return m.handleChannelOpen(packet)
case msgGlobalRequest, msgRequestSuccess, msgRequestFailure:
return m.handleGlobalPacket(packet)
case msgPing:
var msg pingMsg
if err := Unmarshal(packet, &msg); err != nil {
return fmt.Errorf("failed to unmarshal ping@openssh.com message: %w", err)
}
return m.sendMessage(pongMsg(msg))
}
// assume a channel packet.

View File

@@ -64,6 +64,13 @@ type ServerConfig struct {
// Config contains configuration shared between client and server.
Config
// PublicKeyAuthAlgorithms specifies the supported client public key
// authentication algorithms. Note that this should not include certificate
// types since those use the underlying algorithm. This list is sent to the
// client if it supports the server-sig-algs extension. Order is irrelevant.
// If unspecified then a default set of algorithms is used.
PublicKeyAuthAlgorithms []string
hostKeys []Signer
// NoClientAuth is true if clients are allowed to connect without
@@ -201,9 +208,20 @@ func NewServerConn(c net.Conn, config *ServerConfig) (*ServerConn, <-chan NewCha
if fullConf.MaxAuthTries == 0 {
fullConf.MaxAuthTries = 6
}
if len(fullConf.PublicKeyAuthAlgorithms) == 0 {
fullConf.PublicKeyAuthAlgorithms = supportedPubKeyAuthAlgos
} else {
for _, algo := range fullConf.PublicKeyAuthAlgorithms {
if !contains(supportedPubKeyAuthAlgos, algo) {
c.Close()
return nil, nil, nil, fmt.Errorf("ssh: unsupported public key authentication algorithm %s", algo)
}
}
}
// Check if the config contains any unsupported key exchanges
for _, kex := range fullConf.KeyExchanges {
if _, ok := serverForbiddenKexAlgos[kex]; ok {
c.Close()
return nil, nil, nil, fmt.Errorf("ssh: unsupported key exchange %s for server", kex)
}
}
@@ -321,7 +339,7 @@ func checkSourceAddress(addr net.Addr, sourceAddrs string) error {
return fmt.Errorf("ssh: remote address %v is not allowed because of source-address restriction", addr)
}
func gssExchangeToken(gssapiConfig *GSSAPIWithMICConfig, firstToken []byte, s *connection,
func gssExchangeToken(gssapiConfig *GSSAPIWithMICConfig, token []byte, s *connection,
sessionID []byte, userAuthReq userAuthRequestMsg) (authErr error, perms *Permissions, err error) {
gssAPIServer := gssapiConfig.Server
defer gssAPIServer.DeleteSecContext()
@@ -331,7 +349,7 @@ func gssExchangeToken(gssapiConfig *GSSAPIWithMICConfig, firstToken []byte, s *c
outToken []byte
needContinue bool
)
outToken, srcName, needContinue, err = gssAPIServer.AcceptSecContext(firstToken)
outToken, srcName, needContinue, err = gssAPIServer.AcceptSecContext(token)
if err != nil {
return err, nil, nil
}
@@ -353,6 +371,7 @@ func gssExchangeToken(gssapiConfig *GSSAPIWithMICConfig, firstToken []byte, s *c
if err := Unmarshal(packet, userAuthGSSAPITokenReq); err != nil {
return nil, nil, err
}
token = userAuthGSSAPITokenReq.Token
}
packet, err := s.transport.readPacket()
if err != nil {
@@ -407,6 +426,35 @@ func (l ServerAuthError) Error() string {
return "[" + strings.Join(errs, ", ") + "]"
}
// ServerAuthCallbacks defines server-side authentication callbacks.
type ServerAuthCallbacks struct {
// PasswordCallback behaves like [ServerConfig.PasswordCallback].
PasswordCallback func(conn ConnMetadata, password []byte) (*Permissions, error)
// PublicKeyCallback behaves like [ServerConfig.PublicKeyCallback].
PublicKeyCallback func(conn ConnMetadata, key PublicKey) (*Permissions, error)
// KeyboardInteractiveCallback behaves like [ServerConfig.KeyboardInteractiveCallback].
KeyboardInteractiveCallback func(conn ConnMetadata, client KeyboardInteractiveChallenge) (*Permissions, error)
// GSSAPIWithMICConfig behaves like [ServerConfig.GSSAPIWithMICConfig].
GSSAPIWithMICConfig *GSSAPIWithMICConfig
}
// PartialSuccessError can be returned by any of the [ServerConfig]
// authentication callbacks to indicate to the client that authentication has
// partially succeeded, but further steps are required.
type PartialSuccessError struct {
// Next defines the authentication callbacks to apply to further steps. The
// available methods communicated to the client are based on the non-nil
// ServerAuthCallbacks fields.
Next ServerAuthCallbacks
}
func (p *PartialSuccessError) Error() string {
return "ssh: authenticated with partial success"
}
// ErrNoAuth is the error value returned if no
// authentication method has been passed yet. This happens as a normal
// part of the authentication loop, since the client first tries
@@ -420,8 +468,18 @@ func (s *connection) serverAuthenticate(config *ServerConfig) (*Permissions, err
var perms *Permissions
authFailures := 0
noneAuthCount := 0
var authErrs []error
var displayedBanner bool
partialSuccessReturned := false
// Set the initial authentication callbacks from the config. They can be
// changed if a PartialSuccessError is returned.
authConfig := ServerAuthCallbacks{
PasswordCallback: config.PasswordCallback,
PublicKeyCallback: config.PublicKeyCallback,
KeyboardInteractiveCallback: config.KeyboardInteractiveCallback,
GSSAPIWithMICConfig: config.GSSAPIWithMICConfig,
}
userAuthLoop:
for {
@@ -452,6 +510,11 @@ userAuthLoop:
return nil, errors.New("ssh: client attempted to negotiate for unknown service: " + userAuthReq.Service)
}
if s.user != userAuthReq.User && partialSuccessReturned {
return nil, fmt.Errorf("ssh: client changed the user after a partial success authentication, previous user %q, current user %q",
s.user, userAuthReq.User)
}
s.user = userAuthReq.User
if !displayedBanner && config.BannerCallback != nil {
@@ -472,20 +535,18 @@ userAuthLoop:
switch userAuthReq.Method {
case "none":
if config.NoClientAuth {
noneAuthCount++
// We don't allow none authentication after a partial success
// response.
if config.NoClientAuth && !partialSuccessReturned {
if config.NoClientAuthCallback != nil {
perms, authErr = config.NoClientAuthCallback(s)
} else {
authErr = nil
}
}
// allow initial attempt of 'none' without penalty
if authFailures == 0 {
authFailures--
}
case "password":
if config.PasswordCallback == nil {
if authConfig.PasswordCallback == nil {
authErr = errors.New("ssh: password auth not configured")
break
}
@@ -499,17 +560,17 @@ userAuthLoop:
return nil, parseError(msgUserAuthRequest)
}
perms, authErr = config.PasswordCallback(s, password)
perms, authErr = authConfig.PasswordCallback(s, password)
case "keyboard-interactive":
if config.KeyboardInteractiveCallback == nil {
if authConfig.KeyboardInteractiveCallback == nil {
authErr = errors.New("ssh: keyboard-interactive auth not configured")
break
}
prompter := &sshClientKeyboardInteractive{s}
perms, authErr = config.KeyboardInteractiveCallback(s, prompter.Challenge)
perms, authErr = authConfig.KeyboardInteractiveCallback(s, prompter.Challenge)
case "publickey":
if config.PublicKeyCallback == nil {
if authConfig.PublicKeyCallback == nil {
authErr = errors.New("ssh: publickey auth not configured")
break
}
@@ -524,7 +585,7 @@ userAuthLoop:
return nil, parseError(msgUserAuthRequest)
}
algo := string(algoBytes)
if !contains(supportedPubKeyAuthAlgos, underlyingAlgo(algo)) {
if !contains(config.PublicKeyAuthAlgorithms, underlyingAlgo(algo)) {
authErr = fmt.Errorf("ssh: algorithm %q not accepted", algo)
break
}
@@ -543,11 +604,18 @@ userAuthLoop:
if !ok {
candidate.user = s.user
candidate.pubKeyData = pubKeyData
candidate.perms, candidate.result = config.PublicKeyCallback(s, pubKey)
if candidate.result == nil && candidate.perms != nil && candidate.perms.CriticalOptions != nil && candidate.perms.CriticalOptions[sourceAddressCriticalOption] != "" {
candidate.result = checkSourceAddress(
candidate.perms, candidate.result = authConfig.PublicKeyCallback(s, pubKey)
_, isPartialSuccessError := candidate.result.(*PartialSuccessError)
if (candidate.result == nil || isPartialSuccessError) &&
candidate.perms != nil &&
candidate.perms.CriticalOptions != nil &&
candidate.perms.CriticalOptions[sourceAddressCriticalOption] != "" {
if err := checkSourceAddress(
s.RemoteAddr(),
candidate.perms.CriticalOptions[sourceAddressCriticalOption])
candidate.perms.CriticalOptions[sourceAddressCriticalOption]); err != nil {
candidate.result = err
}
}
cache.add(candidate)
}
@@ -559,8 +627,8 @@ userAuthLoop:
if len(payload) > 0 {
return nil, parseError(msgUserAuthRequest)
}
if candidate.result == nil {
_, isPartialSuccessError := candidate.result.(*PartialSuccessError)
if candidate.result == nil || isPartialSuccessError {
okMsg := userAuthPubKeyOkMsg{
Algo: algo,
PubKey: pubKeyData,
@@ -576,13 +644,22 @@ userAuthLoop:
if !ok || len(payload) > 0 {
return nil, parseError(msgUserAuthRequest)
}
// Ensure the declared public key algo is compatible with the
// decoded one. This check will ensure we don't accept e.g.
// ssh-rsa-cert-v01@openssh.com algorithm with ssh-rsa public
// key type. The algorithm and public key type must be
// consistent: both must be certificate algorithms, or neither.
if !contains(algorithmsForKeyFormat(pubKey.Type()), algo) {
authErr = fmt.Errorf("ssh: public key type %q not compatible with selected algorithm %q",
pubKey.Type(), algo)
break
}
// Ensure the public key algo and signature algo
// are supported. Compare the private key
// algorithm name that corresponds to algo with
// sig.Format. This is usually the same, but
// for certs, the names differ.
if !contains(supportedPubKeyAuthAlgos, sig.Format) {
if !contains(config.PublicKeyAuthAlgorithms, sig.Format) {
authErr = fmt.Errorf("ssh: algorithm %q not accepted", sig.Format)
break
}
@@ -601,11 +678,11 @@ userAuthLoop:
perms = candidate.perms
}
case "gssapi-with-mic":
if config.GSSAPIWithMICConfig == nil {
if authConfig.GSSAPIWithMICConfig == nil {
authErr = errors.New("ssh: gssapi-with-mic auth not configured")
break
}
gssapiConfig := config.GSSAPIWithMICConfig
gssapiConfig := authConfig.GSSAPIWithMICConfig
userAuthRequestGSSAPI, err := parseGSSAPIPayload(userAuthReq.Payload)
if err != nil {
return nil, parseError(msgUserAuthRequest)
@@ -661,49 +738,70 @@ userAuthLoop:
break 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 partialSuccess, ok := authErr.(*PartialSuccessError); ok {
// After a partial success error we don't allow changing the user
// name and execute the NoClientAuthCallback.
partialSuccessReturned = true
// In case a partial success is returned, the server may send
// a new set of authentication methods.
authConfig = partialSuccess.Next
// Reset pubkey cache, as the new PublicKeyCallback might
// accept a different set of public keys.
cache = pubKeyCache{}
// Send back a partial success message to the user.
failureMsg.PartialSuccess = true
} else {
// Allow initial attempt of 'none' without penalty.
if authFailures > 0 || userAuthReq.Method != "none" || noneAuthCount != 1 {
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 authentication 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 {
if authConfig.PasswordCallback != nil {
failureMsg.Methods = append(failureMsg.Methods, "password")
}
if config.PublicKeyCallback != nil {
if authConfig.PublicKeyCallback != nil {
failureMsg.Methods = append(failureMsg.Methods, "publickey")
}
if config.KeyboardInteractiveCallback != nil {
if authConfig.KeyboardInteractiveCallback != nil {
failureMsg.Methods = append(failureMsg.Methods, "keyboard-interactive")
}
if config.GSSAPIWithMICConfig != nil && config.GSSAPIWithMICConfig.Server != nil &&
config.GSSAPIWithMICConfig.AllowLogin != nil {
if authConfig.GSSAPIWithMICConfig != nil && authConfig.GSSAPIWithMICConfig.Server != nil &&
authConfig.GSSAPIWithMICConfig.AllowLogin != nil {
failureMsg.Methods = append(failureMsg.Methods, "gssapi-with-mic")
}
if len(failureMsg.Methods) == 0 {
return nil, errors.New("ssh: no authentication methods configured but NoClientAuth is also false")
return nil, errors.New("ssh: no authentication methods available")
}
if err := s.transport.writePacket(Marshal(&failureMsg)); err != nil {

View File

@@ -5,6 +5,7 @@
package ssh
import (
"context"
"errors"
"fmt"
"io"
@@ -332,6 +333,40 @@ func (l *tcpListener) Addr() net.Addr {
return l.laddr
}
// DialContext initiates a connection to the addr from the remote host.
//
// The provided Context must be non-nil. If the context expires before the
// connection is complete, an error is returned. Once successfully connected,
// any expiration of the context will not affect the connection.
//
// See func Dial for additional information.
func (c *Client) DialContext(ctx context.Context, n, addr string) (net.Conn, error) {
if err := ctx.Err(); err != nil {
return nil, err
}
type connErr struct {
conn net.Conn
err error
}
ch := make(chan connErr)
go func() {
conn, err := c.Dial(n, addr)
select {
case ch <- connErr{conn, err}:
case <-ctx.Done():
if conn != nil {
conn.Close()
}
}
}()
select {
case res := <-ch:
return res.conn, res.err
case <-ctx.Done():
return nil, ctx.Err()
}
}
// 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) {

View File

@@ -49,6 +49,9 @@ type transport struct {
rand io.Reader
isClient bool
io.Closer
strictMode bool
initialKEXDone bool
}
// packetCipher represents a combination of SSH encryption/MAC
@@ -74,6 +77,18 @@ type connectionState struct {
pendingKeyChange chan packetCipher
}
func (t *transport) setStrictMode() error {
if t.reader.seqNum != 1 {
return errors.New("ssh: sequence number != 1 when strict KEX mode requested")
}
t.strictMode = true
return nil
}
func (t *transport) setInitialKEXDone() {
t.initialKEXDone = true
}
// prepareKeyChange sets up key material for a keychange. The key changes in
// both directions are triggered by reading and writing a msgNewKey packet
// respectively.
@@ -112,11 +127,12 @@ func (t *transport) printPacket(p []byte, write bool) {
// Read and decrypt next packet.
func (t *transport) readPacket() (p []byte, err error) {
for {
p, err = t.reader.readPacket(t.bufReader)
p, err = t.reader.readPacket(t.bufReader, t.strictMode)
if err != nil {
break
}
if len(p) == 0 || (p[0] != msgIgnore && p[0] != msgDebug) {
// in strict mode we pass through DEBUG and IGNORE packets only during the initial KEX
if len(p) == 0 || (t.strictMode && !t.initialKEXDone) || (p[0] != msgIgnore && p[0] != msgDebug) {
break
}
}
@@ -127,7 +143,7 @@ func (t *transport) readPacket() (p []byte, err error) {
return p, err
}
func (s *connectionState) readPacket(r *bufio.Reader) ([]byte, error) {
func (s *connectionState) readPacket(r *bufio.Reader, strictMode bool) ([]byte, error) {
packet, err := s.packetCipher.readCipherPacket(s.seqNum, r)
s.seqNum++
if err == nil && len(packet) == 0 {
@@ -140,6 +156,9 @@ func (s *connectionState) readPacket(r *bufio.Reader) ([]byte, error) {
select {
case cipher := <-s.pendingKeyChange:
s.packetCipher = cipher
if strictMode {
s.seqNum = 0
}
default:
return nil, errors.New("ssh: got bogus newkeys message")
}
@@ -170,10 +189,10 @@ func (t *transport) writePacket(packet []byte) error {
if debugTransport {
t.printPacket(packet, true)
}
return t.writer.writePacket(t.bufWriter, t.rand, packet)
return t.writer.writePacket(t.bufWriter, t.rand, packet, t.strictMode)
}
func (s *connectionState) writePacket(w *bufio.Writer, rand io.Reader, packet []byte) error {
func (s *connectionState) writePacket(w *bufio.Writer, rand io.Reader, packet []byte, strictMode bool) error {
changeKeys := len(packet) > 0 && packet[0] == msgNewKeys
err := s.packetCipher.writeCipherPacket(s.seqNum, w, rand, packet)
@@ -188,6 +207,9 @@ func (s *connectionState) writePacket(w *bufio.Writer, rand io.Reader, packet []
select {
case cipher := <-s.pendingKeyChange:
s.packetCipher = cipher
if strictMode {
s.seqNum = 0
}
default:
panic("ssh: no key material for msgNewKeys")
}