rebase: update kubernetes to v1.25.0

update kubernetes to latest v1.25.0
release.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

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

@@ -455,21 +455,36 @@ 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 {
-			algo := k.PublicKey().Type()
-			switch algo {
-			case KeyAlgoRSA:
-				msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, []string{SigAlgoRSASHA2512, SigAlgoRSASHA2256, SigAlgoRSA}...)
-			case CertAlgoRSAv01:
-				msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, []string{CertSigAlgoRSASHA2512v01, CertSigAlgoRSASHA2256v01, CertSigAlgoRSAv01}...)
-			default:
-				msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, algo)
+			// 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
+		// 8303, Section 2.1.
+		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.
@@ -589,9 +604,9 @@ 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 {
@@ -618,33 +633,52 @@ 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 {
-		kt := k.PublicKey().Type()
-		if kt == algs.hostKey {
-			hostKey = k
-		} else if signer, ok := k.(AlgorithmSigner); ok {
-			// Some signature algorithms don't show up as key types
-			// so we have to manually check for a compatible host key.
-			switch kt {
-			case KeyAlgoRSA:
-				if algs.hostKey == SigAlgoRSASHA2256 || algs.hostKey == SigAlgoRSASHA2512 {
-					hostKey = &rsaSigner{signer, algs.hostKey}
-				}
-			case CertAlgoRSAv01:
-				if algs.hostKey == CertSigAlgoRSASHA2256v01 || algs.hostKey == CertSigAlgoRSASHA2512v01 {
-					hostKey = &rsaSigner{signer, certToPrivAlgo(algs.hostKey)}
-				}
+// 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
+}
+
+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
+}
 
-	r, err := kex.Server(t.conn, t.config.Rand, magics, hostKey)
+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
@@ -655,7 +689,7 @@ func (t *handshakeTransport) client(kex kexAlgorithm, algs *algorithms, magics *
 		return nil, err
 	}
 
-	if err := verifyHostKeySignature(hostKey, algs.hostKey, result); err != nil {
+	if err := verifyHostKeySignature(hostKey, t.algorithms.hostKey, result); err != nil {
 		return nil, err
 	}