vendor: update buildkit to 2943a0838

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/golang.org/x/crypto/ssh/agent/client.go

@@ -102,8 +102,9 @@ type ConstraintExtension struct {
 
 // AddedKey describes an SSH key to be added to an Agent.
 type AddedKey struct {
-	// PrivateKey must be a *rsa.PrivateKey, *dsa.PrivateKey or
-	// *ecdsa.PrivateKey, which will be inserted into the agent.
+	// PrivateKey must be a *rsa.PrivateKey, *dsa.PrivateKey,
+	// ed25519.PrivateKey or *ecdsa.PrivateKey, which will be inserted into the
+	// agent.
 	PrivateKey interface{}
 	// Certificate, if not nil, is communicated to the agent and will be
 	// stored with the key.
@@ -566,6 +567,17 @@ func (c *client) insertKey(s interface{}, comment string, constraints []byte) er
 			Comments:    comment,
 			Constraints: constraints,
 		})
+	case ed25519.PrivateKey:
+		req = ssh.Marshal(ed25519KeyMsg{
+			Type:        ssh.KeyAlgoED25519,
+			Pub:         []byte(k)[32:],
+			Priv:        []byte(k),
+			Comments:    comment,
+			Constraints: constraints,
+		})
+	// This function originally supported only *ed25519.PrivateKey, however the
+	// general idiom is to pass ed25519.PrivateKey by value, not by pointer.
+	// We still support the pointer variant for backwards compatibility.
 	case *ed25519.PrivateKey:
 		req = ssh.Marshal(ed25519KeyMsg{
 			Type:        ssh.KeyAlgoED25519,
@@ -683,6 +695,18 @@ func (c *client) insertCert(s interface{}, cert *ssh.Certificate, comment string
 			Comments:    comment,
 			Constraints: constraints,
 		})
+	case ed25519.PrivateKey:
+		req = ssh.Marshal(ed25519CertMsg{
+			Type:        cert.Type(),
+			CertBytes:   cert.Marshal(),
+			Pub:         []byte(k)[32:],
+			Priv:        []byte(k),
+			Comments:    comment,
+			Constraints: constraints,
+		})
+	// This function originally supported only *ed25519.PrivateKey, however the
+	// general idiom is to pass ed25519.PrivateKey by value, not by pointer.
+	// We still support the pointer variant for backwards compatibility.
 	case *ed25519.PrivateKey:
 		req = ssh.Marshal(ed25519CertMsg{
 			Type:        cert.Type(),

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

@@ -414,8 +414,8 @@ func (c *CertChecker) CheckCert(principal string, cert *Certificate) error {
 	return nil
 }
 
-// SignCert sets c.SignatureKey to the authority's public key and stores a
-// Signature, by authority, in the certificate.
+// SignCert signs the certificate with an authority, setting the Nonce,
+// SignatureKey, and Signature fields.
 func (c *Certificate) SignCert(rand io.Reader, authority Signer) error {
 	c.Nonce = make([]byte, 32)
 	if _, err := io.ReadFull(rand, c.Nonce); err != nil {

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

@@ -119,7 +119,7 @@ var cipherModes = map[string]*cipherMode{
 	chacha20Poly1305ID: {64, 0, newChaCha20Cipher},
 
 	// CBC mode is insecure and so is not included in the default config.
-	// (See http://www.isg.rhul.ac.uk/~kp/SandPfinal.pdf). If absolutely
+	// (See https://www.ieee-security.org/TC/SP2013/papers/4977a526.pdf). If absolutely
 	// needed, it's possible to specify a custom Config to enable it.
 	// You should expect that an active attacker can recover plaintext if
 	// you do.

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

@@ -36,7 +36,7 @@ func (c *connection) clientAuthenticate(config *ClientConfig) error {
 
 	// during the authentication phase the client first attempts the "none" method
 	// then any untried methods suggested by the server.
-	tried := make(map[string]bool)
+	var tried []string
 	var lastMethods []string
 
 	sessionID := c.transport.getSessionID()
@@ -49,7 +49,9 @@ func (c *connection) clientAuthenticate(config *ClientConfig) error {
 			// success
 			return nil
 		} else if ok == authFailure {
-			tried[auth.method()] = true
+			if m := auth.method(); !contains(tried, m) {
+				tried = append(tried, m)
+			}
 		}
 		if methods == nil {
 			methods = lastMethods
@@ -61,7 +63,7 @@ func (c *connection) clientAuthenticate(config *ClientConfig) error {
 	findNext:
 		for _, a := range config.Auth {
 			candidateMethod := a.method()
-			if tried[candidateMethod] {
+			if contains(tried, candidateMethod) {
 				continue
 			}
 			for _, meth := range methods {
@@ -72,16 +74,16 @@ func (c *connection) clientAuthenticate(config *ClientConfig) error {
 			}
 		}
 	}
-	return fmt.Errorf("ssh: unable to authenticate, attempted methods %v, no supported methods remain", keys(tried))
+	return fmt.Errorf("ssh: unable to authenticate, attempted methods %v, no supported methods remain", tried)
 }
 
-func keys(m map[string]bool) []string {
-	s := make([]string, 0, len(m))
-
-	for key := range m {
-		s = append(s, key)
+func contains(list []string, e string) bool {
+	for _, s := range list {
+		if s == e {
+			return true
+		}
 	}
-	return s
+	return false
 }
 
 // An AuthMethod represents an instance of an RFC 4252 authentication method.

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

@@ -572,7 +572,7 @@ func (gex *dhGEXSHA) diffieHellman(theirPublic, myPrivate *big.Int) (*big.Int, e
 	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,
@@ -677,7 +677,7 @@ func (gex *dhGEXSHA) Client(c packetConn, randSource io.Reader, magics *handshak
 // 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 Signer) (result *kexResult, err error) {
 	// Receive GexRequest
 	packet, err := c.readPacket()
 	if err != nil {

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

@@ -1246,15 +1246,23 @@ func passphraseProtectedOpenSSHKey(passphrase []byte) openSSHDecryptFunc {
 		}
 		key, iv := k[:32], k[32:]
 
-		if cipherName != "aes256-ctr" {
-			return nil, fmt.Errorf("ssh: unknown cipher %q, only supports %q", cipherName, "aes256-ctr")
-		}
 		c, err := aes.NewCipher(key)
 		if err != nil {
 			return nil, err
 		}
-		ctr := cipher.NewCTR(c, iv)
-		ctr.XORKeyStream(privKeyBlock, privKeyBlock)
+		switch cipherName {
+		case "aes256-ctr":
+			ctr := cipher.NewCTR(c, iv)
+			ctr.XORKeyStream(privKeyBlock, privKeyBlock)
+		case "aes256-cbc":
+			if len(privKeyBlock)%c.BlockSize() != 0 {
+				return nil, fmt.Errorf("ssh: invalid encrypted private key length, not a multiple of the block size")
+			}
+			cbc := cipher.NewCBCDecrypter(c, iv)
+			cbc.CryptBlocks(privKeyBlock, privKeyBlock)
+		default:
+			return nil, fmt.Errorf("ssh: unknown cipher %q, only supports %q or %q", cipherName, "aes256-ctr", "aes256-cbc")
+		}
 
 		return privKeyBlock, nil
 	}

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

@@ -240,7 +240,7 @@ func (m *mux) onePacket() error {
 	id := binary.BigEndian.Uint32(packet[1:])
 	ch := m.chanList.getChan(id)
 	if ch == nil {
-		return fmt.Errorf("ssh: invalid channel %d", id)
+		return m.handleUnknownChannelPacket(id, packet)
 	}
 
 	return ch.handlePacket(packet)
@@ -328,3 +328,24 @@ func (m *mux) openChannel(chanType string, extra []byte) (*channel, error) {
 		return nil, fmt.Errorf("ssh: unexpected packet in response to channel open: %T", msg)
 	}
 }
+
+func (m *mux) handleUnknownChannelPacket(id uint32, packet []byte) error {
+	msg, err := decode(packet)
+	if err != nil {
+		return err
+	}
+
+	switch msg := msg.(type) {
+	// RFC 4254 section 5.4 says unrecognized channel requests should
+	// receive a failure response.
+	case *channelRequestMsg:
+		if msg.WantReply {
+			return m.sendMessage(channelRequestFailureMsg{
+				PeersID: msg.PeersID,
+			})
+		}
+		return nil
+	default:
+		return fmt.Errorf("ssh: invalid channel %d", id)
+	}
+}

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

@@ -113,6 +113,7 @@ func NewTerminal(c io.ReadWriter, prompt string) *Terminal {
 }
 
 const (
+	keyCtrlC     = 3
 	keyCtrlD     = 4
 	keyCtrlU     = 21
 	keyEnter     = '\r'
@@ -151,8 +152,12 @@ func bytesToKey(b []byte, pasteActive bool) (rune, []byte) {
 		switch b[0] {
 		case 1: // ^A
 			return keyHome, b[1:]
+		case 2: // ^B
+			return keyLeft, b[1:]
 		case 5: // ^E
 			return keyEnd, b[1:]
+		case 6: // ^F
+			return keyRight, b[1:]
 		case 8: // ^H
 			return keyBackspace, b[1:]
 		case 11: // ^K
@@ -738,6 +743,9 @@ func (t *Terminal) readLine() (line string, err error) {
 						return "", io.EOF
 					}
 				}
+				if key == keyCtrlC {
+					return "", io.EOF
+				}
 				if key == keyPasteStart {
 					t.pasteActive = true
 					if len(t.line) == 0 {