func CheckHostKey(HostKey string) (checkHostKey func(string, net.Addr, ssh.PublicKey) error) {
var err error
var public ssh.PublicKey
var publices []ssh.PublicKey
rest := []byte(HostKey)
for {
public, _, _, rest, err = ssh.ParseAuthorizedKey(rest)
if err != nil {
err = nil
break
}
publices = append(publices, public)
}
checkHostKey = func(hostname string, remote net.Addr, key ssh.PublicKey) (err error) {
hostkey := key.Marshal()
log.Debug("remote hostkey: %s, type: %s", hostname, key.Type())
for _, public := range publices {
if key.Type() == public.Type() && bytes.Compare(hostkey, public.Marshal()) == 0 {
log.Info("host key match: %s", hostname)
return nil
}
}
log.Info("host key not match: %s", hostname)
return ErrHostKey
}
return
}
func (l *sshListener) checkLogin(conn ssh.ConnMetadata, key ssh.PublicKey) (*ssh.Permissions, error) {
if bytes.Equal(key.Marshal(), l.id.PublicKey().Marshal()) && conn.User() == "termite" {
return nil, nil
}
return nil, fmt.Errorf("denied")
}
// Remove removes all identities with the given public key.
func (r *keyring) Remove(key ssh.PublicKey) error {
r.mu.Lock()
defer r.mu.Unlock()
if r.locked {
return errLocked
}
want := key.Marshal()
found := false
for i := 0; i < len(r.keys); {
if bytes.Equal(r.keys[i].signer.PublicKey().Marshal(), want) {
found = true
r.keys[i] = r.keys[len(r.keys)-1]
r.keys = r.keys[len(r.keys)-1:]
continue
} else {
i++
}
}
if !found {
return errors.New("agent: key not found")
}
return nil
}
func (k *storedHostKey) Check(addr string, remote net.Addr, key ssh.PublicKey) error {
k.checkCount++
algo := key.Type()
if k.keys == nil || bytes.Compare(key.Marshal(), k.keys[algo]) != 0 {
return fmt.Errorf("host key mismatch. Got %q, want %q", key, k.keys[algo])
}
return nil
}
func SSHFingerprint(pubkey ssh.PublicKey) (fingerprint string) {
binary := pubkey.Marshal()
hash := md5.Sum(binary)
// now add the colons
fingerprint = fmt.Sprintf("%02x", (hash[0]))
for i := 1; i < len(hash); i += 1 {
fingerprint += ":" + fmt.Sprintf("%02x", (hash[i]))
}
return fingerprint
}
func MarshalPublickKey(key ssh.PublicKey) string {
pemBlock := &pem.Block{
Type: "", // The type, taken from the preamble (i.e. "RSA PRIVATE KEY").
// Headers: map[string]string{}, // Optional headers.
Bytes: key.Marshal(), // The decoded bytes of the contents. Typically a DER encoded ASN.1 structure.
}
pemData := pem.EncodeToMemory(pemBlock)
pemArray := strings.Split(string(pemData), "\n")
return strings.Join(pemArray[1:len(pemArray)-2], "")
}
// Check is called during the handshake to check the server's public key for
// unexpected changes. The key argument is in SSH wire format. It can be parsed
// using ssh.ParsePublicKey. The address before DNS resolution is passed in the
// addr argument, so the key can also be checked against the hostname.
// It returns any error encountered while checking the public key. A nil return
// value indicates that the key was either successfully verified (against an
// existing known_hosts entry), or accepted by the user as a new key.
func (kc *HostKeyChecker) Check(addr string, remote net.Addr, key gossh.PublicKey) error {
remoteAddr, err := kc.addrToHostPort(remote.String())
if err != nil {
return err
}
algoStr := algoString(key.Type())
keyFingerprintStr := md5String(md5.Sum(key.Marshal()))
hostKeys, err := kc.m.GetHostKeys()
_, ok := err.(*os.PathError)
if err != nil && !ok {
log.Errorf("Failed to read known_hosts file %v: %v", kc.m.String(), err)
}
mismatched := false
for pattern, keys := range hostKeys {
if !matchHost(remoteAddr, pattern) {
continue
}
for _, hostKey := range keys {
// Any matching key is considered a success, irrespective of previous failures
if hostKey.Type() == key.Type() && bytes.Compare(hostKey.Marshal(), key.Marshal()) == 0 {
return nil
}
// TODO(jonboulle): could be super friendly like the OpenSSH client
// and note exactly which key failed (file + line number)
mismatched = true
}
}
if mismatched {
fmt.Fprintf(os.Stderr, warningRemoteHostChanged, algoStr, keyFingerprintStr, kc.m.String())
return ErrUnmatchKey
}
// If we get this far, we haven't matched on any of the hostname patterns,
// so it's considered a new key. Prompt the user to trust it.
if !kc.trustHost(remoteAddr, algoStr, keyFingerprintStr) {
fmt.Fprintln(os.Stderr, "Host key verification failed.")
return ErrUntrustHost
}
if err := kc.m.PutHostKey(remoteAddr, key); err != nil {
fmt.Fprintf(os.Stderr, "Failed to add the host to the list of known hosts (%v).\n", kc.m)
return nil
}
fmt.Fprintf(os.Stderr, "Warning: Permanently added '%v' (%v) to the list of known hosts.\n", remoteAddr, algoStr)
return nil
}
// Sign returns a signature for the data.
func (r *keyring) Sign(key ssh.PublicKey, data []byte) (*ssh.Signature, error) {
r.mu.Lock()
defer r.mu.Unlock()
if r.locked {
return nil, errLocked
}
wanted := key.Marshal()
for _, k := range r.keys {
if bytes.Equal(k.signer.PublicKey().Marshal(), wanted) {
return k.signer.Sign(rand.Reader, data)
}
}
return nil, errors.New("not found")
}
func testAgentInterface(t *testing.T, agent Agent, key interface{}, cert *ssh.Certificate) {
signer, err := ssh.NewSignerFromKey(key)
if err != nil {
t.Fatalf("NewSignerFromKey: %v", err)
}
// The agent should start up empty.
if keys, err := agent.List(); err != nil {
t.Fatalf("RequestIdentities: %v", err)
} else if len(keys) > 0 {
t.Fatalf("got %d keys, want 0: %v", len(keys), keys)
}
// Attempt to insert the key, with certificate if specified.
var pubKey ssh.PublicKey
if cert != nil {
err = agent.Add(key, cert, "comment")
pubKey = cert
} else {
err = agent.Add(key, nil, "comment")
pubKey = signer.PublicKey()
}
if err != nil {
t.Fatalf("insert: %v", err)
}
// Did the key get inserted successfully?
if keys, err := agent.List(); err != nil {
t.Fatalf("List: %v", err)
} else if len(keys) != 1 {
t.Fatalf("got %v, want 1 key", keys)
} else if keys[0].Comment != "comment" {
t.Fatalf("key comment: got %v, want %v", keys[0].Comment, "comment")
} else if !bytes.Equal(keys[0].Blob, pubKey.Marshal()) {
t.Fatalf("key mismatch")
}
// Can the agent make a valid signature?
data := []byte("hello")
sig, err := agent.Sign(pubKey, data)
if err != nil {
t.Fatalf("Sign: %v", err)
}
if err := pubKey.Verify(data, sig); err != nil {
t.Fatalf("key signature Verify: %v", err)
}
}
func (srv *Server) findPubkey(key ssh.PublicKey) (username string, err error) {
pubkey := base64.StdEncoding.EncodeToString(key.Marshal())
v := &url.Values{}
v.Add("pubkey", pubkey)
type PubkeyRslt struct {
Name string
Username string
}
rslt := &PubkeyRslt{}
err = srv.GetJson("/l/pubk", false, v, rslt)
if err != nil {
return
}
username = rslt.Username
return
}
// Sign has the agent sign the data using a protocol 2 key as defined
// in [PROTOCOL.agent] section 2.6.2.
func (c *client) Sign(key ssh.PublicKey, data []byte) (*ssh.Signature, error) {
req := ssh.Marshal(signRequestAgentMsg{
KeyBlob: key.Marshal(),
Data: data,
})
msg, err := c.call(req)
if err != nil {
return nil, err
}
switch msg := msg.(type) {
case *signResponseAgentMsg:
var sig ssh.Signature
if err := ssh.Unmarshal(msg.SigBlob, &sig); err != nil {
return nil, err
}
return &sig, nil
case *failureAgentMsg:
return nil, errors.New("agent: failed to sign challenge")
}
panic("unreachable")
}
func (d *sshDialer) checkHost(hostname string, remote net.Addr, key ssh.PublicKey) error {
if bytes.Equal(key.Marshal(), d.identity.PublicKey().Marshal()) {
return nil
}
return fmt.Errorf("key mismatch")
}
func (c *client) Remove(key ssh.PublicKey) error {
req := ssh.Marshal(&agentRemoveIdentityMsg{
KeyBlob: key.Marshal(),
})
return c.simpleCall(req)
}
func (k *storedHostKey) Add(key ssh.PublicKey) {
if k.keys == nil {
k.keys = map[string][]byte{}
}
k.keys[key.Type()] = key.Marshal()
}
func SerializeKey(key ssh.PublicKey) string {
return string(key.Marshal())
}