Add Next Protocol Negotiation.

12 files changed, 524 insertions, 1 deletions

diff --git a/ssl/s3_both.c b/ssl/s3_both.c
index a6d869df59..89f7c42f03 100644
--- a/ssl/s3_both.c
+++ b/ssl/s3_both.c
@@ -202,15 +202,40 @@ int ssl3_send_finished(SSL *s, int a, int b, const char *sender, int slen)
 	return(ssl3_do_write(s,SSL3_RT_HANDSHAKE));
 	}
 
+#ifndef OPENSSL_NO_NPN
+/* ssl3_take_mac calculates the Finished MAC for the handshakes messages seen to far. */
+static void ssl3_take_mac(SSL *s)
+	{
+	const char *sender;
+	int slen;
+
+	if (s->state & SSL_ST_CONNECT)
+		{
+		sender=s->method->ssl3_enc->server_finished_label;
+		slen=s->method->ssl3_enc->server_finished_label_len;
+		}
+	else
+		{
+		sender=s->method->ssl3_enc->client_finished_label;
+		slen=s->method->ssl3_enc->client_finished_label_len;
+		}
+
+	s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
+		sender,slen,s->s3->tmp.peer_finish_md);
+	}
+#endif
+
 int ssl3_get_finished(SSL *s, int a, int b)
 	{
 	int al,i,ok;
 	long n;
 	unsigned char *p;
 
+#ifdef OPENSSL_NO_NPN
 	/* the mac has already been generated when we received the
 	 * change cipher spec message and is in s->s3->tmp.peer_finish_md
 	 */ 
+#endif
 
 	n=s->method->ssl_get_message(s,
 		a,
@@ -514,6 +539,15 @@ long ssl3_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 		s->init_num += i;
 		n -= i;
 		}
+
+#ifndef OPENSSL_NO_NPN
+	/* If receiving Finished, record MAC of prior handshake messages for
+	 * Finished verification. */
+	if (*s->init_buf->data == SSL3_MT_FINISHED)
+		ssl3_take_mac(s);
+#endif
+
+	/* Feed this message into MAC computation. */
 	ssl3_finish_mac(s, (unsigned char *)s->init_buf->data, s->init_num + 4);
 	if (s->msg_callback)
 		s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data, (size_t)s->init_num + 4, s, s->msg_callback_arg);
diff --git a/ssl/s3_clnt.c b/ssl/s3_clnt.c
index 41769febab..aa5604c1dd 100644
--- a/ssl/s3_clnt.c
+++ b/ssl/s3_clnt.c
@@ -423,7 +423,15 @@ int ssl3_connect(SSL *s)
 			ret=ssl3_send_change_cipher_spec(s,
 				SSL3_ST_CW_CHANGE_A,SSL3_ST_CW_CHANGE_B);
 			if (ret <= 0) goto end;
+
+#if defined(OPENSSL_NO_TLSEXT) || defined(OPENSSL_NO_NPN)
 			s->state=SSL3_ST_CW_FINISHED_A;
+#else
+			if (s->next_proto_negotiated)
+				s->state=SSL3_ST_CW_NEXT_PROTO_A;
+			else
+				s->state=SSL3_ST_CW_FINISHED_A;
+#endif
 			s->init_num=0;
 
 			s->session->cipher=s->s3->tmp.new_cipher;
@@ -451,6 +459,15 @@ int ssl3_connect(SSL *s)
 
 			break;
 
+#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NPN)
+		case SSL3_ST_CW_NEXT_PROTO_A:
+		case SSL3_ST_CW_NEXT_PROTO_B:
+			ret=ssl3_send_next_proto(s);
+			if (ret <= 0) goto end;
+			s->state=SSL3_ST_CW_FINISHED_A;
+			break;
+#endif
+
 		case SSL3_ST_CW_FINISHED_A:
 		case SSL3_ST_CW_FINISHED_B:
 			ret=ssl3_send_finished(s,
@@ -3000,6 +3017,32 @@ err:
  */
 
 #ifndef OPENSSL_NO_TLSEXT
+# ifndef OPENSSL_NO_NPN
+int ssl3_send_next_proto(SSL *s)
+	{
+	unsigned int len, padding_len;
+	unsigned char *d;
+
+	if (s->state == SSL3_ST_CW_NEXT_PROTO_A)
+		{
+		len = s->next_proto_negotiated_len;
+		padding_len = 32 - ((len + 2) % 32);
+		d = (unsigned char *)s->init_buf->data;
+		d[4] = len;
+		memcpy(d + 5, s->next_proto_negotiated, len);
+		d[5 + len] = padding_len;
+		memset(d + 6 + len, 0, padding_len);
+		*(d++)=SSL3_MT_NEXT_PROTO;
+		l2n3(2 + len + padding_len, d);
+		s->state = SSL3_ST_CW_NEXT_PROTO_B;
+		s->init_num = 4 + 2 + len + padding_len;
+		s->init_off = 0;
+		}
+
+	return ssl3_do_write(s, SSL3_RT_HANDSHAKE);
+	}
+# endif
+
 int ssl3_check_finished(SSL *s)
 	{
 	int ok;
diff --git a/ssl/s3_lib.c b/ssl/s3_lib.c
index d6b047c995..497f64fee5 100644
--- a/ssl/s3_lib.c
+++ b/ssl/s3_lib.c
@@ -2230,6 +2230,15 @@ void ssl3_clear(SSL *s)
 	s->s3->num_renegotiations=0;
 	s->s3->in_read_app_data=0;
 	s->version=SSL3_VERSION;
+
+#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NPN)
+	if (s->next_proto_negotiated)
+		{
+		OPENSSL_free(s->next_proto_negotiated);
+		s->next_proto_negotiated = NULL;
+		s->next_proto_negotiated_len = 0;
+		}
+#endif
 	}
 
 long ssl3_ctrl(SSL *s, int cmd, long larg, void *parg)
diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c
index b30c032b74..08a7233b4c 100644
--- a/ssl/s3_pkt.c
+++ b/ssl/s3_pkt.c
@@ -1374,8 +1374,10 @@ err:
 int ssl3_do_change_cipher_spec(SSL *s)
 	{
 	int i;
+#ifdef OPENSSL_NO_NPN
 	const char *sender;
 	int slen;
+#endif
 
 	if (s->state & SSL_ST_ACCEPT)
 		i=SSL3_CHANGE_CIPHER_SERVER_READ;
@@ -1398,6 +1400,7 @@ int ssl3_do_change_cipher_spec(SSL *s)
 	if (!s->method->ssl3_enc->change_cipher_state(s,i))
 		return(0);
 
+#ifdef OPENSSL_NO_NPN
 	/* we have to record the message digest at
 	 * this point so we can get it before we read
 	 * the finished message */
@@ -1414,6 +1417,7 @@ int ssl3_do_change_cipher_spec(SSL *s)
 
 	s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
 		sender,slen,s->s3->tmp.peer_finish_md);
+#endif
 
 	return(1);
 	}
diff --git a/ssl/s3_srvr.c b/ssl/s3_srvr.c
index 92f73b6681..57e516f6de 100644
--- a/ssl/s3_srvr.c
+++ b/ssl/s3_srvr.c
@@ -538,7 +538,14 @@ int ssl3_accept(SSL *s)
 				 * the client uses its key from the certificate
 				 * for key exchange.
 				 */
+#if defined(OPENSSL_NO_TLSEXT) || defined(OPENSSL_NO_NPN)
 				s->state=SSL3_ST_SR_FINISHED_A;
+#else
+				if (s->s3->next_proto_neg_seen)
+					s->state=SSL3_ST_SR_NEXT_PROTO_A;
+				else
+					s->state=SSL3_ST_SR_FINISHED_A;
+#endif
 				s->init_num = 0;
 				}
 			else
@@ -581,10 +588,27 @@ int ssl3_accept(SSL *s)
 			ret=ssl3_get_cert_verify(s);
 			if (ret <= 0) goto end;
 
+#if defined(OPENSSL_NO_TLSEXT) || defined(OPENSSL_NO_NPN)
 			s->state=SSL3_ST_SR_FINISHED_A;
+#else
+			if (s->s3->next_proto_neg_seen)
+				s->state=SSL3_ST_SR_NEXT_PROTO_A;
+			else
+				s->state=SSL3_ST_SR_FINISHED_A;
+#endif
 			s->init_num=0;
 			break;
 
+#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NPN)
+		case SSL3_ST_SR_NEXT_PROTO_A:
+		case SSL3_ST_SR_NEXT_PROTO_B:
+			ret=ssl3_get_next_proto(s);
+			if (ret <= 0) goto end;
+			s->init_num = 0;
+			s->state=SSL3_ST_SR_FINISHED_A;
+			break;
+#endif
+
 		case SSL3_ST_SR_FINISHED_A:
 		case SSL3_ST_SR_FINISHED_B:
 			ret=ssl3_get_finished(s,SSL3_ST_SR_FINISHED_A,
@@ -655,7 +679,16 @@ int ssl3_accept(SSL *s)
 			if (ret <= 0) goto end;
 			s->state=SSL3_ST_SW_FLUSH;
 			if (s->hit)
+				{
+#if defined(OPENSSL_NO_TLSEXT) || defined(OPENSSL_NO_NPN)
 				s->s3->tmp.next_state=SSL3_ST_SR_FINISHED_A;
+#else
+				if (s->s3->next_proto_neg_seen)
+					s->s3->tmp.next_state=SSL3_ST_SR_NEXT_PROTO_A;
+				else
+					s->s3->tmp.next_state=SSL3_ST_SR_FINISHED_A;
+#endif
+				}
 			else
 				s->s3->tmp.next_state=SSL_ST_OK;
 			s->init_num=0;
@@ -3177,4 +3210,72 @@ int ssl3_send_cert_status(SSL *s)
 	/* SSL3_ST_SW_CERT_STATUS_B */
 	return(ssl3_do_write(s,SSL3_RT_HANDSHAKE));
 	}
+
+# ifndef OPENSSL_NO_NPN
+/* ssl3_get_next_proto reads a Next Protocol Negotiation handshake message. It
+ * sets the next_proto member in s if found */
+int ssl3_get_next_proto(SSL *s)
+	{
+	int ok;
+	unsigned proto_len, padding_len;
+	long n;
+	const unsigned char *p;
+
+	/* Clients cannot send a NextProtocol message if we didn't see the
+	 * extension in their ClientHello */
+	if (!s->s3->next_proto_neg_seen)
+		{
+		SSLerr(SSL_F_SSL3_GET_NEXT_PROTO,SSL_R_GOT_NEXT_PROTO_WITHOUT_EXTENSION);
+		return -1;
+		}
+
+	n=s->method->ssl_get_message(s,
+		SSL3_ST_SR_NEXT_PROTO_A,
+		SSL3_ST_SR_NEXT_PROTO_B,
+		SSL3_MT_NEXT_PROTO,
+		129,
+		&ok);
+
+	if (!ok)
+		return((int)n);
+
+	/* s->state doesn't reflect whether ChangeCipherSpec has been received
+	 * in this handshake, but s->s3->change_cipher_spec does (will be reset
+	 * by ssl3_get_finished). */
+	if (!s->s3->change_cipher_spec)
+		{
+		SSLerr(SSL_F_SSL3_GET_NEXT_PROTO,SSL_R_GOT_NEXT_PROTO_BEFORE_A_CCS);
+		return -1;
+		}
+
+	if (n < 2)
+		return 0;  /* The body must be > 1 bytes long */
+
+	p=(unsigned char *)s->init_msg;
+
+	/* The payload looks like:
+	 *   uint8 proto_len;
+	 *   uint8 proto[proto_len];
+	 *   uint8 padding_len;
+	 *   uint8 padding[padding_len];
+	 */
+	proto_len = p[0];
+	if (proto_len + 2 > s->init_num)
+		return 0;
+	padding_len = p[proto_len + 1];
+	if (proto_len + padding_len + 2 != s->init_num)
+		return 0;
+
+	s->next_proto_negotiated = OPENSSL_malloc(proto_len);
+	if (!s->next_proto_negotiated)
+		{
+		SSLerr(SSL_F_SSL3_GET_NEXT_PROTO,ERR_R_MALLOC_FAILURE);
+		return 0;
+		}
+	memcpy(s->next_proto_negotiated, p + 1, proto_len);
+	s->next_proto_negotiated_len = proto_len;
+
+	return 1;
+	}
+# endif
 #endif
diff --git a/ssl/ssl.h b/ssl/ssl.h
index e6244b0011..971208be78 100644
--- a/ssl/ssl.h
+++ b/ssl/ssl.h
@@ -852,6 +852,25 @@ struct ssl_ctx_st
 	/* draft-rescorla-tls-opaque-prf-input-00.txt information */
 	int (*tlsext_opaque_prf_input_callback)(SSL *, void *peerinput, size_t len, void *arg);
 	void *tlsext_opaque_prf_input_callback_arg;
+
+# ifndef OPENSSL_NO_NPN
+	/* Next protocol negotiation information */
+	/* (for experimental NPN extension). */
+
+	/* For a server, this contains a callback function by which the set of
+	 * advertised protocols can be provided. */
+	int (*next_protos_advertised_cb)(SSL *s, const unsigned char **buf,
+			                 unsigned int *len, void *arg);
+	void *next_protos_advertised_cb_arg;
+	/* For a client, this contains a callback function that selects the
+	 * next protocol from the list provided by the server. */
+	int (*next_proto_select_cb)(SSL *s, unsigned char **out,
+				    unsigned char *outlen,
+				    const unsigned char *in,
+				    unsigned int inlen,
+				    void *arg);
+	void *next_proto_select_cb_arg;
+# endif
 #endif
 
 #ifndef OPENSSL_NO_PSK
@@ -923,6 +942,30 @@ int SSL_CTX_set_client_cert_engine(SSL_CTX *ctx, ENGINE *e);
 #endif
 void SSL_CTX_set_cookie_generate_cb(SSL_CTX *ctx, int (*app_gen_cookie_cb)(SSL *ssl, unsigned char *cookie, unsigned int *cookie_len));
 void SSL_CTX_set_cookie_verify_cb(SSL_CTX *ctx, int (*app_verify_cookie_cb)(SSL *ssl, unsigned char *cookie, unsigned int cookie_len));
+#ifndef OPENSSL_NO_NPN
+void SSL_CTX_set_next_protos_advertised_cb(SSL_CTX *s,
+					   int (*cb) (SSL *ssl,
+						      const unsigned char **out,
+						      unsigned int *outlen,
+						      void *arg), void *arg);
+void SSL_CTX_set_next_proto_select_cb(SSL_CTX *s,
+				      int (*cb) (SSL *ssl, unsigned char **out,
+						 unsigned char *outlen,
+						 const unsigned char *in,
+						 unsigned int inlen, void *arg),
+				      void *arg);
+
+int SSL_select_next_proto(unsigned char **out, unsigned char *outlen,
+			  const unsigned char *in, unsigned int inlen,
+			  const unsigned char *client, unsigned int client_len);
+void SSL_get0_next_proto_negotiated(const SSL *s, const unsigned char **data,
+				    unsigned *len);
+
+#define OPENSSL_NPN_UNSUPPORTED	0
+#define OPENSSL_NPN_NEGOTIATED	1
+#define OPENSSL_NPN_NO_OVERLAP	2
+
+#endif
 
 #ifndef OPENSSL_NO_PSK
 /* the maximum length of the buffer given to callbacks containing the
@@ -1179,6 +1222,19 @@ struct ssl_st
 	void *tls_session_secret_cb_arg;
 
 	SSL_CTX * initial_ctx; /* initial ctx, used to store sessions */
+
+#ifndef OPENSSL_NO_NPN
+	/* Next protocol negotiation. For the client, this is the protocol that
+	 * we sent in NextProtocol and is set when handling ServerHello
+	 * extensions.
+	 *
+	 * For a server, this is the client's selected_protocol from
+	 * NextProtocol and is set when handling the NextProtocol message,
+	 * before the Finished message. */
+	unsigned char *next_proto_negotiated;
+	unsigned char next_proto_negotiated_len;
+#endif
+
 #define session_ctx initial_ctx
 #else
 #define session_ctx ctx
@@ -1910,6 +1966,7 @@ void ERR_load_SSL_strings(void);
 #define SSL_F_SSL3_GET_KEY_EXCHANGE			 141
 #define SSL_F_SSL3_GET_MESSAGE				 142
 #define SSL_F_SSL3_GET_NEW_SESSION_TICKET		 283
+#define SSL_F_SSL3_GET_NEXT_PROTO			 304
 #define SSL_F_SSL3_GET_RECORD				 143
 #define SSL_F_SSL3_GET_SERVER_CERTIFICATE		 144
 #define SSL_F_SSL3_GET_SERVER_DONE			 145
@@ -2107,6 +2164,8 @@ void ERR_load_SSL_strings(void);
 #define SSL_R_EXCESSIVE_MESSAGE_SIZE			 152
 #define SSL_R_EXTRA_DATA_IN_MESSAGE			 153
 #define SSL_R_GOT_A_FIN_BEFORE_A_CCS			 154
+#define SSL_R_GOT_NEXT_PROTO_BEFORE_A_CCS		 346
+#define SSL_R_GOT_NEXT_PROTO_WITHOUT_EXTENSION		 347
 #define SSL_R_HTTPS_PROXY_REQUEST			 155
 #define SSL_R_HTTP_REQUEST				 156
 #define SSL_R_ILLEGAL_PADDING				 283
diff --git a/ssl/ssl3.h b/ssl/ssl3.h
index baaa89e717..e98aac5aa8 100644
--- a/ssl/ssl3.h
+++ b/ssl/ssl3.h
@@ -455,6 +455,12 @@ typedef struct ssl3_state_st
 	void *server_opaque_prf_input;
 	size_t server_opaque_prf_input_len;
 
+#ifndef OPENSSL_NO_NPN
+	/* Set if we saw the Next Protocol Negotiation extension from
+	   our peer. */
+	int next_proto_neg_seen;
+#endif
+
 	struct	{
 		/* actually only needs to be 16+20 */
 		unsigned char cert_verify_md[EVP_MAX_MD_SIZE*2];
@@ -546,6 +552,10 @@ typedef struct ssl3_state_st
 #define SSL3_ST_CW_CERT_VRFY_B		(0x191|SSL_ST_CONNECT)
 #define SSL3_ST_CW_CHANGE_A		(0x1A0|SSL_ST_CONNECT)
 #define SSL3_ST_CW_CHANGE_B		(0x1A1|SSL_ST_CONNECT)
+#ifndef OPENSSL_NO_NPN
+#define SSL3_ST_CW_NEXT_PROTO_A		(0x200|SSL_ST_CONNECT)
+#define SSL3_ST_CW_NEXT_PROTO_B		(0x201|SSL_ST_CONNECT)
+#endif
 #define SSL3_ST_CW_FINISHED_A		(0x1B0|SSL_ST_CONNECT)
 #define SSL3_ST_CW_FINISHED_B		(0x1B1|SSL_ST_CONNECT)
 /* read from server */
@@ -591,6 +601,10 @@ typedef struct ssl3_state_st
 #define SSL3_ST_SR_CERT_VRFY_B		(0x1A1|SSL_ST_ACCEPT)
 #define SSL3_ST_SR_CHANGE_A		(0x1B0|SSL_ST_ACCEPT)
 #define SSL3_ST_SR_CHANGE_B		(0x1B1|SSL_ST_ACCEPT)
+#ifndef OPENSSL_NO_NPN
+#define SSL3_ST_SR_NEXT_PROTO_A		(0x210|SSL_ST_ACCEPT)
+#define SSL3_ST_SR_NEXT_PROTO_B		(0x211|SSL_ST_ACCEPT)
+#endif
 #define SSL3_ST_SR_FINISHED_A		(0x1C0|SSL_ST_ACCEPT)
 #define SSL3_ST_SR_FINISHED_B		(0x1C1|SSL_ST_ACCEPT)
 /* write to client */
@@ -615,6 +629,9 @@ typedef struct ssl3_state_st
 #define SSL3_MT_CLIENT_KEY_EXCHANGE		16
 #define SSL3_MT_FINISHED			20
 #define SSL3_MT_CERTIFICATE_STATUS		22
+#ifndef OPENSSL_NO_NPN
+#define SSL3_MT_NEXT_PROTO			67
+#endif
 #define DTLS1_MT_HELLO_VERIFY_REQUEST    3
 
 
diff --git a/ssl/ssl_err.c b/ssl/ssl_err.c
index 0eed464749..414f9d93fe 100644
--- a/ssl/ssl_err.c
+++ b/ssl/ssl_err.c
@@ -1,6 +1,6 @@
 /* ssl/ssl_err.c */
 /* ====================================================================
- * Copyright (c) 1999-2009 The OpenSSL Project.  All rights reserved.
+ * Copyright (c) 1999-2010 The OpenSSL Project.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -155,6 +155,7 @@ static ERR_STRING_DATA SSL_str_functs[]=
 {ERR_FUNC(SSL_F_SSL3_GET_KEY_EXCHANGE),	"SSL3_GET_KEY_EXCHANGE"},
 {ERR_FUNC(SSL_F_SSL3_GET_MESSAGE),	"SSL3_GET_MESSAGE"},
 {ERR_FUNC(SSL_F_SSL3_GET_NEW_SESSION_TICKET),	"SSL3_GET_NEW_SESSION_TICKET"},
+{ERR_FUNC(SSL_F_SSL3_GET_NEXT_PROTO),	"SSL3_GET_NEXT_PROTO"},
 {ERR_FUNC(SSL_F_SSL3_GET_RECORD),	"SSL3_GET_RECORD"},
 {ERR_FUNC(SSL_F_SSL3_GET_SERVER_CERTIFICATE),	"SSL3_GET_SERVER_CERTIFICATE"},
 {ERR_FUNC(SSL_F_SSL3_GET_SERVER_DONE),	"SSL3_GET_SERVER_DONE"},
@@ -355,6 +356,8 @@ static ERR_STRING_DATA SSL_str_reasons[]=
 {ERR_REASON(SSL_R_EXCESSIVE_MESSAGE_SIZE),"excessive message size"},
 {ERR_REASON(SSL_R_EXTRA_DATA_IN_MESSAGE) ,"extra data in message"},
 {ERR_REASON(SSL_R_GOT_A_FIN_BEFORE_A_CCS),"got a fin before a ccs"},
+{ERR_REASON(SSL_R_GOT_NEXT_PROTO_BEFORE_A_CCS),"got next proto before a ccs"},
+{ERR_REASON(SSL_R_GOT_NEXT_PROTO_WITHOUT_EXTENSION),"got next proto without seeing extension"},
 {ERR_REASON(SSL_R_HTTPS_PROXY_REQUEST)   ,"https proxy request"},
 {ERR_REASON(SSL_R_HTTP_REQUEST)          ,"http request"},
 {ERR_REASON(SSL_R_ILLEGAL_PADDING)       ,"illegal padding"},
diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index 3c74ec179c..f59a45411e 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -353,6 +353,9 @@ SSL *SSL_new(SSL_CTX *ctx)
 	s->tlsext_ocsp_resplen = -1;
 	CRYPTO_add(&ctx->references,1,CRYPTO_LOCK_SSL_CTX);
 	s->initial_ctx=ctx;
+# ifndef OPENSSL_NO_NPN
+	s->next_proto_negotiated = NULL;
+# endif
 #endif
 
 	s->verify_result=X509_V_OK;
@@ -586,6 +589,11 @@ void SSL_free(SSL *s)
 		kssl_ctx_free(s->kssl_ctx);
 #endif	/* OPENSSL_NO_KRB5 */
 
+#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NPN)
+	if (s->next_proto_negotiated)
+		OPENSSL_free(s->next_proto_negotiated);
+#endif
+
 	OPENSSL_free(s);
 	}
 
@@ -1476,6 +1484,124 @@ int SSL_get_servername_type(const SSL *s)
 		return TLSEXT_NAMETYPE_host_name;
 	return -1;
 	}
+
+# ifndef OPENSSL_NO_NPN
+/* SSL_select_next_proto implements the standard protocol selection. It is
+ * expected that this function is called from the callback set by
+ * SSL_CTX_set_next_proto_select_cb.
+ *
+ * The protocol data is assumed to be a vector of 8-bit, length prefixed byte
+ * strings. The length byte itself is not included in the length. A byte
+ * string of length 0 is invalid. No byte string may be truncated.
+ *
+ * The current, but experimental algorithm for selecting the protocol is:
+ *
+ * 1) If the server doesn't support NPN then this is indicated to the
+ * callback. In this case, the client application has to abort the connection
+ * or have a default application level protocol.
+ *
+ * 2) If the server supports NPN, but advertises an empty list then the
+ * client selects the first protcol in its list, but indicates via the
+ * API that this fallback case was enacted.
+ *
+ * 3) Otherwise, the client finds the first protocol in the server's list
+ * that it supports and selects this protocol. This is because it's
+ * assumed that the server has better information about which protocol
+ * a client should use.
+ *
+ * 4) If the client doesn't support any of the server's advertised
+ * protocols, then this is treated the same as case 2.
+ *
+ * It returns either
+ * OPENSSL_NPN_NEGOTIATED if a common protocol was found, or
+ * OPENSSL_NPN_NO_OVERLAP if the fallback case was reached.
+ */
+int SSL_select_next_proto(unsigned char **out, unsigned char *outlen, const unsigned char *server, unsigned int server_len, const unsigned char *client, unsigned int client_len)
+	{
+	unsigned int i, j;
+	const unsigned char *result;
+	int status = OPENSSL_NPN_UNSUPPORTED;
+
+	/* For each protocol in server preference order, see if we support it. */
+	for (i = 0; i < server_len; )
+		{
+		for (j = 0; j < client_len; )
+			{
+			if (server[i] == client[j] &&
+			    memcmp(&server[i+1], &client[j+1], server[i]) == 0)
+				{
+				/* We found a match */
+				result = &server[i];
+				status = OPENSSL_NPN_NEGOTIATED;
+				goto found;
+				}
+			j += client[j];
+			j++;
+			}
+		i += server[i];
+		i++;
+		}
+
+	/* There's no overlap between our protocols and the server's list. */
+	result = client;
+	status = OPENSSL_NPN_NO_OVERLAP;
+
+	found:
+	*out = (unsigned char *) result + 1;
+	*outlen = result[0];
+	return status;
+	}
+
+/* SSL_get0_next_proto_negotiated sets *data and *len to point to the client's
+ * requested protocol for this connection and returns 0. If the client didn't
+ * request any protocol, then *data is set to NULL.
+ *
+ * Note that the client can request any protocol it chooses. The value returned
+ * from this function need not be a member of the list of supported protocols
+ * provided by the callback.
+ */
+void SSL_get0_next_proto_negotiated(const SSL *s, const unsigned char **data, unsigned *len)
+	{
+	*data = s->next_proto_negotiated;
+	if (!*data) {
+		*len = 0;
+	} else {
+		*len = s->next_proto_negotiated_len;
+	}
+}
+
+/* SSL_CTX_set_next_protos_advertised_cb sets a callback that is called when a
+ * TLS server needs a list of supported protocols for Next Protocol
+ * Negotiation. The returned list must be in wire format.  The list is returned
+ * by setting |out| to point to it and |outlen| to its length. This memory will
+ * not be modified, but one should assume that the SSL* keeps a reference to
+ * it.
+ *
+ * The callback should return SSL_TLSEXT_ERR_OK if it wishes to advertise. Otherwise, no
+ * such extension will be included in the ServerHello. */
+void SSL_CTX_set_next_protos_advertised_cb(SSL_CTX *ctx, int (*cb) (SSL *ssl, const unsigned char **out, unsigned int *outlen, void *arg), void *arg)
+	{
+	ctx->next_protos_advertised_cb = cb;
+	ctx->next_protos_advertised_cb_arg = arg;
+	}
+
+/* SSL_CTX_set_next_proto_select_cb sets a callback that is called when a
+ * client needs to select a protocol from the server's provided list. |out|
+ * must be set to point to the selected protocol (which may be within |in|).
+ * The length of the protocol name must be written into |outlen|. The server's
+ * advertised protocols are provided in |in| and |inlen|. The callback can
+ * assume that |in| is syntactically valid.
+ *
+ * The client must select a protocol. It is fatal to the connection if this
+ * callback returns a value other than SSL_TLSEXT_ERR_OK.
+ */
+void SSL_CTX_set_next_proto_select_cb(SSL_CTX *ctx, int (*cb) (SSL *s, unsigned char **out, unsigned char *outlen, const unsigned char *in, unsigned int inlen, void *arg), void *arg)
+	{
+	ctx->next_proto_select_cb = cb;
+	ctx->next_proto_select_cb_arg = arg;
+	}
+
+# endif
 #endif
 
 static unsigned long ssl_session_hash(const SSL_SESSION *a)
@@ -1640,6 +1766,10 @@ SSL_CTX *SSL_CTX_new(const SSL_METHOD *meth)
 	ret->tlsext_status_cb = 0;
 	ret->tlsext_status_arg = NULL;
 
+# ifndef OPENSSL_NO_NPN
+	ret->next_protos_advertised_cb = 0;
+	ret->next_proto_select_cb = 0;
+# endif
 #endif
 #ifndef OPENSSL_NO_PSK
 	ret->psk_identity_hint=NULL;
diff --git a/ssl/ssl_locl.h b/ssl/ssl_locl.h
index 41f0f77597..95ec8a6bdb 100644
--- a/ssl/ssl_locl.h
+++ b/ssl/ssl_locl.h
@@ -968,6 +968,9 @@ int ssl3_get_server_certificate(SSL *s);
 int ssl3_check_cert_and_algorithm(SSL *s);
 #ifndef OPENSSL_NO_TLSEXT
 int ssl3_check_finished(SSL *s);
+# ifndef OPENSSL_NO_NPN
+int ssl3_send_next_proto(SSL *s);
+# endif
 #endif
 
 int dtls1_client_hello(SSL *s);
@@ -986,6 +989,9 @@ int ssl3_check_client_hello(SSL *s);
 int ssl3_get_client_certificate(SSL *s);
 int ssl3_get_client_key_exchange(SSL *s);
 int ssl3_get_cert_verify(SSL *s);
+#ifndef OPENSSL_NO_NPN
+int ssl3_get_next_proto(SSL *s);
+#endif
 
 int dtls1_send_hello_request(SSL *s);
 int dtls1_send_server_hello(SSL *s);
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index ef40e5e6f8..39b5e72533 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -494,6 +494,18 @@ unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned cha
 			i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
 		}
 
+#ifndef OPENSSL_NO_NPN
+	if (s->ctx->next_proto_select_cb && !s->s3->tmp.finish_md_len)
+		{
+		/* The client advertises an emtpy extension to indicate its
+		 * support for Next Protocol Negotiation */
+		if (limit - ret - 4 < 0)
+			return NULL;
+		s2n(TLSEXT_TYPE_next_proto_neg,ret);
+		s2n(0,ret);
+		}
+#endif
+
 	if ((extdatalen = ret-p-2)== 0) 
 		return p;
 
@@ -505,6 +517,9 @@ unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned cha
 	{
 	int extdatalen=0;
 	unsigned char *ret = p;
+#ifndef OPENSSL_NO_NPN
+	char next_proto_neg_seen;
+#endif
 
 	/* don't add extensions for SSLv3, unless doing secure renegotiation */
 	if (s->version == SSL3_VERSION && !s->s3->send_connection_binding)
@@ -618,6 +633,28 @@ unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned cha
 
 		}
 
+#ifndef OPENSSL_NO_NPN
+	next_proto_neg_seen = s->s3->next_proto_neg_seen;
+	s->s3->next_proto_neg_seen = 0;
+	if (next_proto_neg_seen && s->ctx->next_protos_advertised_cb)
+		{
+		const unsigned char *npa;
+		unsigned int npalen;
+		int r;
+
+		r = s->ctx->next_protos_advertised_cb(s, &npa, &npalen, s->ctx->next_protos_advertised_cb_arg);
+		if (r == SSL_TLSEXT_ERR_OK)
+			{
+			if ((long)(limit - ret - 4 - npalen) < 0) return NULL;
+			s2n(TLSEXT_TYPE_next_proto_neg,ret);
+			s2n(npalen,ret);
+			memcpy(ret, npa, npalen);
+			ret += npalen;
+			s->s3->next_proto_neg_seen = 1;
+			}
+		}
+#endif
+
 	if ((extdatalen = ret-p-2)== 0) 
 		return p;
 
@@ -958,6 +995,28 @@ int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
 				else
 					s->tlsext_status_type = -1;
 			}
+#ifndef OPENSSL_NO_NPN
+		else if (type == TLSEXT_TYPE_next_proto_neg &&
+                         s->s3->tmp.finish_md_len == 0)
+			{
+			/* We shouldn't accept this extension on a
+			 * renegotiation.
+			 *
+			 * s->new_session will be set on renegotiation, but we
+			 * probably shouldn't rely that it couldn't be set on
+			 * the initial renegotation too in certain cases (when
+			 * there's some other reason to disallow resuming an
+			 * earlier session -- the current code won't be doing
+			 * anything like that, but this might change).
+
+			 * A valid sign that there's been a previous handshake
+			 * in this connection is if s->s3->tmp.finish_md_len >
+			 * 0.  (We are talking about a check that will happen
+			 * in the Hello protocol round, well before a new
+			 * Finished message could have been computed.) */
+			s->s3->next_proto_neg_seen = 1;
+			}
+#endif
 
 		/* session ticket processed earlier */
 		data+=size;
@@ -981,6 +1040,26 @@ int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
 	return 1;
 	}
 
+#ifndef OPENSSL_NO_NPN
+/* ssl_next_proto_validate validates a Next Protocol Negotiation block. No
+ * elements of zero length are allowed and the set of elements must exactly fill
+ * the length of the block. */
+static char ssl_next_proto_validate(unsigned char *d, unsigned len)
+	{
+	unsigned int off = 0;
+
+	while (off < len)
+		{
+		if (d[off] == 0)
+			return 0;
+		off += d[off];
+		off++;
+		}
+
+	return off == len;
+	}
+#endif
+
 int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
 	{
 	unsigned short length;
@@ -1115,6 +1194,39 @@ int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
 			/* Set flag to expect CertificateStatus message */
 			s->tlsext_status_expected = 1;
 			}
+#ifndef OPENSSL_NO_NPN
+		else if (type == TLSEXT_TYPE_next_proto_neg)
+			{
+			unsigned char *selected;
+			unsigned char selected_len;
+
+			/* We must have requested it. */
+			if ((s->ctx->next_proto_select_cb == NULL))
+				{
+				*al = TLS1_AD_UNSUPPORTED_EXTENSION;
+				return 0;
+				}
+			/* The data must be valid */
+			if (!ssl_next_proto_validate(data, size))
+				{
+				*al = TLS1_AD_DECODE_ERROR;
+				return 0;
+				}
+			if (s->ctx->next_proto_select_cb(s, &selected, &selected_len, data, size, s->ctx->next_proto_select_cb_arg) != SSL_TLSEXT_ERR_OK)
+				{
+				*al = TLS1_AD_INTERNAL_ERROR;
+				return 0;
+				}
+			s->next_proto_negotiated = OPENSSL_malloc(selected_len);
+			if (!s->next_proto_negotiated)
+				{
+				*al = TLS1_AD_INTERNAL_ERROR;
+				return 0;
+				}
+			memcpy(s->next_proto_negotiated, selected, selected_len);
+			s->next_proto_negotiated_len = selected_len;
+			}
+#endif
 		else if (type == TLSEXT_TYPE_renegotiate)
 			{
 			if(!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
diff --git a/ssl/tls1.h b/ssl/tls1.h
index b32b713ca8..c1b6546941 100644
--- a/ssl/tls1.h
+++ b/ssl/tls1.h
@@ -208,6 +208,11 @@ extern "C" {
 /* Temporary extension type */
 #define TLSEXT_TYPE_renegotiate                 0xff01
 
+#ifndef OPENSSL_NO_NPN
+/* This is not an IANA defined extension number */
+#define TLSEXT_TYPE_next_proto_neg		13172
+#endif
+
 /* NameType value from RFC 3546 */
 #define TLSEXT_NAMETYPE_host_name 0
 /* status request value from RFC 3546 */