Update vendor (whatsapp)

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

@@ -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

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

@@ -633,6 +633,30 @@ 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 {