From 68b33cc5c7aa1bb98e95bfb4b61c34192a7a50e3 Mon Sep 17 00:00:00 2001
From: Ben Laurie <ben@openssl.org>
Date: Sun, 13 Nov 2011 21:55:42 +0000
Subject: [PATCH] Add Next Protocol Negotiation.

---
 apps/apps.c     |  44 +++++++++++++++++
 apps/apps.h     |   4 ++
 apps/s_client.c |  78 +++++++++++++++++++++++++++++
 apps/s_server.c |  71 ++++++++++++++++++++++++--
 ssl/s3_both.c   |  36 ++++++++++++--
 ssl/s3_clnt.c   |  44 +++++++++++++++++
 ssl/s3_lib.c    |   9 ++++
 ssl/s3_pkt.c    |   4 ++
 ssl/s3_srvr.c   | 101 +++++++++++++++++++++++++++++++++++++
 ssl/ssl.h       |  61 +++++++++++++++++++++++
 ssl/ssl3.h      |  10 ++++
 ssl/ssl_err.c   |   5 +-
 ssl/ssl_lib.c   | 129 ++++++++++++++++++++++++++++++++++++++++++++++++
 ssl/ssl_locl.h  |   6 +++
 ssl/t1_lib.c    | 112 +++++++++++++++++++++++++++++++++++++++++
 ssl/tls1.h      |   5 ++
 16 files changed, 712 insertions(+), 7 deletions(-)

diff --git a/apps/apps.c b/apps/apps.c
index feb7ed46e6..b346558d2c 100644
--- a/apps/apps.c
+++ b/apps/apps.c
@@ -2693,6 +2693,50 @@ void jpake_server_auth(BIO *out, BIO *conn, const char *secret)
 
 #endif
 
+#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)
+/* next_protos_parse parses a comma separated list of strings into a string
+ * in a format suitable for passing to SSL_CTX_set_next_protos_advertised.
+ *   outlen: (output) set to the length of the resulting buffer on success.
+ *   err: (maybe NULL) on failure, an error message line is written to this BIO.
+ *   in: a NUL termianted string like "abc,def,ghi"
+ *
+ *   returns: a malloced buffer or NULL on failure.
+ */
+unsigned char *next_protos_parse(unsigned short *outlen, const char *in)
+	{
+	size_t len;
+	unsigned char *out;
+	size_t i, start = 0;
+
+	len = strlen(in);
+	if (len >= 65535)
+		return NULL;
+
+	out = OPENSSL_malloc(strlen(in) + 1);
+	if (!out)
+		return NULL;
+
+	for (i = 0; i <= len; ++i)
+		{
+		if (i == len || in[i] == ',')
+			{
+			if (i - start > 255)
+				{
+				OPENSSL_free(out);
+				return NULL;
+				}
+			out[start] = i - start;
+			start = i + 1;
+			}
+		else
+			out[i+1] = in[i];
+		}
+
+	*outlen = len + 1;
+	return out;
+	}
+#endif  /* !OPENSSL_NO_TLSEXT && !OPENSSL_NO_NEXTPROTONEG */
+
 /*
  * Platform-specific sections
  */
diff --git a/apps/apps.h b/apps/apps.h
index 42a388648e..c1ca99da12 100644
--- a/apps/apps.h
+++ b/apps/apps.h
@@ -331,6 +331,10 @@ void jpake_client_auth(BIO *out, BIO *conn, const char *secret);
 void jpake_server_auth(BIO *out, BIO *conn, const char *secret);
 #endif
 
+#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)
+unsigned char *next_protos_parse(unsigned short *outlen, const char *in);
+#endif  /* !OPENSSL_NO_TLSEXT && !OPENSSL_NO_NEXTPROTONEG */
+
 #define FORMAT_UNDEF    0
 #define FORMAT_ASN1     1
 #define FORMAT_TEXT     2
diff --git a/apps/s_client.c b/apps/s_client.c
index cde4828796..5f251a4247 100644
--- a/apps/s_client.c
+++ b/apps/s_client.c
@@ -354,6 +354,9 @@ static void sc_usage(void)
 	BIO_printf(bio_err," -tlsextdebug      - hex dump of all TLS extensions received\n");
 	BIO_printf(bio_err," -status           - request certificate status from server\n");
 	BIO_printf(bio_err," -no_ticket        - disable use of RFC4507bis session tickets\n");
+# if !defined(OPENSSL_NO_NEXTPROTONEG)
+	BIO_printf(bio_err," -nextprotoneg arg - enable NPN extension, considering named protocols supported (comma-separated list)\n");
+# endif
 #endif
 	BIO_printf(bio_err," -legacy_renegotiation - enable use of legacy renegotiation (dangerous)\n");
 	}
@@ -484,6 +487,40 @@ static char * MS_CALLBACK missing_srp_username_callback(SSL *s, void *arg)
 	}
 
 #endif
+
+# ifndef OPENSSL_NO_NEXTPROTONEG
+/* This the context that we pass to next_proto_cb */
+typedef struct tlsextnextprotoctx_st {
+	unsigned char *data;
+	unsigned short len;
+	int status;
+} tlsextnextprotoctx;
+
+static tlsextnextprotoctx next_proto;
+
+static int next_proto_cb(SSL *s, unsigned char **out, unsigned char *outlen, const unsigned char *in, unsigned int inlen, void *arg)
+	{
+	tlsextnextprotoctx *ctx = arg;
+
+	if (!c_quiet)
+		{
+		/* We can assume that |in| is syntactically valid. */
+		unsigned i;
+		BIO_printf(bio_c_out, "Protocols advertised by server: ");
+		for (i = 0; i < inlen; )
+			{
+			if (i)
+				BIO_write(bio_c_out, ", ", 2);
+			BIO_write(bio_c_out, &in[i + 1], in[i]);
+			i += in[i] + 1;
+			}
+		BIO_write(bio_c_out, "\n", 1);
+		}
+
+	ctx->status = SSL_select_next_proto(out, outlen, in, inlen, ctx->data, ctx->len);
+	return SSL_TLSEXT_ERR_OK;
+	}
+# endif
 #endif
 
 enum
@@ -550,6 +587,9 @@ int MAIN(int argc, char **argv)
 	char *servername = NULL; 
         tlsextctx tlsextcbp = 
         {NULL,0};
+# ifndef OPENSSL_NO_NEXTPROTONEG
+	const char *next_proto_neg_in = NULL;
+# endif
 #endif
 	char *sess_in = NULL;
 	char *sess_out = NULL;
@@ -821,6 +861,13 @@ int MAIN(int argc, char **argv)
 #ifndef OPENSSL_NO_TLSEXT
 		else if	(strcmp(*argv,"-no_ticket") == 0)
 			{ off|=SSL_OP_NO_TICKET; }
+# ifndef OPENSSL_NO_NEXTPROTONEG
+		else if (strcmp(*argv,"-nextprotoneg") == 0)
+			{
+			if (--argc < 1) goto bad;
+			next_proto_neg_in = *(++argv);
+			}
+# endif
 #endif
 		else if (strcmp(*argv,"-serverpref") == 0)
 			off|=SSL_OP_CIPHER_SERVER_PREFERENCE;
@@ -927,6 +974,21 @@ bad:
 	OpenSSL_add_ssl_algorithms();
 	SSL_load_error_strings();
 
+#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)
+	next_proto.status = -1;
+	if (next_proto_neg_in)
+		{
+		next_proto.data = next_protos_parse(&next_proto.len, next_proto_neg_in);
+		if (next_proto.data == NULL)
+			{
+			BIO_printf(bio_err, "Error parsing -nextprotoneg argument\n");
+			goto end;
+			}
+		}
+	else
+		next_proto.data = NULL;
+#endif
+
 #ifndef OPENSSL_NO_ENGINE
         e = setup_engine(bio_err, engine_id, 1);
 	if (ssl_client_engine_id)
@@ -1056,6 +1118,11 @@ bad:
 	 */
 	if (socket_type == SOCK_DGRAM) SSL_CTX_set_read_ahead(ctx, 1);
 
+#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)
+	if (next_proto.data)
+		SSL_CTX_set_next_proto_select_cb(ctx, next_proto_cb, &next_proto);
+#endif
+
 	if (state) SSL_CTX_set_info_callback(ctx,apps_ssl_info_callback);
 	if (cipher != NULL)
 		if(!SSL_CTX_set_cipher_list(ctx,cipher)) {
@@ -1949,6 +2016,17 @@ static void print_stuff(BIO *bio, SSL *s, int full)
 	}
 #endif
 
+#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)
+	if (next_proto.status != -1) {
+		const unsigned char *proto;
+		unsigned int proto_len;
+		SSL_get0_next_proto_negotiated(s, &proto, &proto_len);
+		BIO_printf(bio, "Next protocol: (%d) ", next_proto.status);
+		BIO_write(bio, proto, proto_len);
+		BIO_write(bio, "\n", 1);
+	}
+#endif
+
 	SSL_SESSION_print(bio,SSL_get_session(s));
 	BIO_printf(bio,"---\n");
 	if (peer != NULL)
diff --git a/apps/s_server.c b/apps/s_server.c
index 0137b31cd1..19f4fb25e2 100644
--- a/apps/s_server.c
+++ b/apps/s_server.c
@@ -537,6 +537,9 @@ static void sv_usage(void)
 	BIO_printf(bio_err," -tlsextdebug  - hex dump of all TLS extensions received\n");
 	BIO_printf(bio_err," -no_ticket    - disable use of RFC4507bis session tickets\n");
 	BIO_printf(bio_err," -legacy_renegotiation - enable use of legacy renegotiation (dangerous)\n");
+# ifndef OPENSSL_NO_NEXTPROTONEG
+	BIO_printf(bio_err," -nextprotoneg arg - set the advertised protocols for the NPN extension (comma-separated list)\n");
+# endif
 #endif
 	}
 
@@ -871,6 +874,26 @@ BIO_printf(err, "cert_status: received %d ids\n", sk_OCSP_RESPID_num(ids));
 	ret = SSL_TLSEXT_ERR_ALERT_FATAL;
 	goto done;
 	}
+
+# ifndef OPENSSL_NO_NEXTPROTONEG
+/* This is the context that we pass to next_proto_cb */
+typedef struct tlsextnextprotoctx_st {
+	unsigned char *data;
+	unsigned int len;
+} tlsextnextprotoctx;
+
+static int next_proto_cb(SSL *s, const unsigned char **data, unsigned int *len, void *arg)
+	{
+	tlsextnextprotoctx *next_proto = arg;
+
+	*data = next_proto->data;
+	*len = next_proto->len;
+
+	return SSL_TLSEXT_ERR_OK;
+	}
+# endif  /* ndef OPENSSL_NO_NEXTPROTONEG */
+
+
 #endif
 
 int MAIN(int, char **);
@@ -909,9 +932,11 @@ int MAIN(int argc, char *argv[])
 #ifndef OPENSSL_NO_TLSEXT
 	EVP_PKEY *s_key2 = NULL;
 	X509 *s_cert2 = NULL;
-#endif
-#ifndef OPENSSL_NO_TLSEXT
         tlsextctx tlsextcbp = {NULL, NULL, SSL_TLSEXT_ERR_ALERT_WARNING};
+# ifndef OPENSSL_NO_NEXTPROTONEG
+	const char *next_proto_neg_in = NULL;
+	tlsextnextprotoctx next_proto;
+# endif
 #endif
 #ifndef OPENSSL_NO_PSK
 	/* by default do not send a PSK identity hint */
@@ -1267,7 +1292,13 @@ int MAIN(int argc, char *argv[])
 			if (--argc < 1) goto bad;
 			s_key_file2= *(++argv);
 			}
-			
+# ifndef OPENSSL_NO_NEXTPROTONEG
+		else if	(strcmp(*argv,"-nextprotoneg") == 0)
+			{
+			if (--argc < 1) goto bad;
+			next_proto_neg_in = *(++argv);
+			}
+# endif
 #endif
 #if !defined(OPENSSL_NO_JPAKE) && !defined(OPENSSL_NO_PSK)
 		else if (strcmp(*argv,"-jpake") == 0)
@@ -1372,6 +1403,22 @@ bad:
 				goto end;
 				}
 			}
+
+# ifndef OPENSSL_NO_NEXTPROTONEG
+		if (next_proto_neg_in)
+			{
+			unsigned short len;
+			next_proto.data = next_protos_parse(&len,
+				next_proto_neg_in);
+			if (next_proto.data == NULL)
+				goto end;
+			next_proto.len = len;
+			}
+		else
+			{
+			next_proto.data = NULL;
+			}
+# endif
 #endif
 		}
 
@@ -1552,6 +1599,11 @@ bad:
 		if (vpm)
 			SSL_CTX_set1_param(ctx2, vpm);
 		}
+
+# ifndef OPENSSL_NO_NEXTPROTONEG
+	if (next_proto.data)
+		SSL_CTX_set_next_protos_advertised_cb(ctx, next_proto_cb, &next_proto);
+# endif
 #endif 
 
 #ifndef OPENSSL_NO_DH
@@ -2257,6 +2309,10 @@ static int init_ssl_connection(SSL *con)
 #ifndef OPENSSL_NO_KRB5
 	char *client_princ;
 #endif
+#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)
+	const unsigned char *next_proto_neg;
+	unsigned next_proto_neg_len;
+#endif
 
 	if ((i=SSL_accept(con)) <= 0)
 		{
@@ -2296,6 +2352,15 @@ static int init_ssl_connection(SSL *con)
 		BIO_printf(bio_s_out,"Shared ciphers:%s\n",buf);
 	str=SSL_CIPHER_get_name(SSL_get_current_cipher(con));
 	BIO_printf(bio_s_out,"CIPHER is %s\n",(str != NULL)?str:"(NONE)");
+#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)
+	SSL_get0_next_proto_negotiated(con, &next_proto_neg, &next_proto_neg_len);
+	if (next_proto_neg)
+		{
+		BIO_printf(bio_s_out,"NEXTPROTO is ");
+		BIO_write(bio_s_out, next_proto_neg, next_proto_neg_len);
+		BIO_printf(bio_s_out, "\n");
+		}
+#endif
 	if (SSL_cache_hit(con)) BIO_printf(bio_s_out,"Reused session-id\n");
 	if (SSL_ctrl(con,SSL_CTRL_GET_FLAGS,0,NULL) &
 		TLS1_FLAGS_TLS_PADDING_BUG)
diff --git a/ssl/s3_both.c b/ssl/s3_both.c
index a6d869df59..b63460a56d 100644
--- a/ssl/s3_both.c
+++ b/ssl/s3_both.c
@@ -202,15 +202,38 @@ 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_NEXTPROTONEG
+/* 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;
 
-	/* the mac has already been generated when we received the
-	 * change cipher spec message and is in s->s3->tmp.peer_finish_md
-	 */ 
+#ifdef OPENSSL_NO_NEXTPROTONEG
+	/* 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 +537,13 @@ 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_NEXTPROTONEG
+	/* 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 6cf6e6f378..1578f17e97 100644
--- a/ssl/s3_clnt.c
+++ b/ssl/s3_clnt.c
@@ -460,7 +460,16 @@ 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_NEXTPROTONEG)
 			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;
@@ -488,6 +497,15 @@ int ssl3_connect(SSL *s)
 
 			break;
 
+#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)
+		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,
@@ -3236,6 +3254,32 @@ err:
 	return(0);
 	}
 
+#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)
+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  /* !OPENSSL_NO_TLSEXT && !OPENSSL_NO_NEXTPROTONEG */
+
 /* Check to see if handshake is full or resumed. Usually this is just a
  * case of checking to see if a cache hit has occurred. In the case of
  * session tickets we have to check the next message to be sure.
diff --git a/ssl/s3_lib.c b/ssl/s3_lib.c
index 14608a888a..a6778c213a 100644
--- a/ssl/s3_lib.c
+++ b/ssl/s3_lib.c
@@ -3062,6 +3062,15 @@ 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_NEXTPROTONEG)
+	if (s->next_proto_negotiated)
+		{
+		OPENSSL_free(s->next_proto_negotiated);
+		s->next_proto_negotiated = NULL;
+		s->next_proto_negotiated_len = 0;
+		}
+#endif
 	}
 
 #ifndef OPENSSL_NO_SRP
diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c
index 33be6badbc..5e0cbdc3df 100644
--- a/ssl/s3_pkt.c
+++ b/ssl/s3_pkt.c
@@ -1392,8 +1392,10 @@ err:
 int ssl3_do_change_cipher_spec(SSL *s)
 	{
 	int i;
+#ifdef OPENSSL_NO_NEXTPROTONEG
 	const char *sender;
 	int slen;
+#endif
 
 	if (s->state & SSL_ST_ACCEPT)
 		i=SSL3_CHANGE_CIPHER_SERVER_READ;
@@ -1416,6 +1418,7 @@ int ssl3_do_change_cipher_spec(SSL *s)
 	if (!s->method->ssl3_enc->change_cipher_state(s,i))
 		return(0);
 
+#ifdef OPENSSL_NO_NEXTPROTONEG
 	/* we have to record the message digest at
 	 * this point so we can get it before we read
 	 * the finished message */
@@ -1432,6 +1435,7 @@ 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 af9ed3ff5f..4088598d23 100644
--- a/ssl/s3_srvr.c
+++ b/ssl/s3_srvr.c
@@ -598,7 +598,14 @@ int ssl3_accept(SSL *s)
 				 * the client uses its key from the certificate
 				 * for key exchange.
 				 */
+#if defined(OPENSSL_NO_TLSEXT) || defined(OPENSSL_NO_NEXTPROTONEG)
 				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 if (TLS1_get_version(s) >= TLS1_2_VERSION)
@@ -659,10 +666,27 @@ int ssl3_accept(SSL *s)
 			ret=ssl3_get_cert_verify(s);
 			if (ret <= 0) goto end;
 
+#if defined(OPENSSL_NO_TLSEXT) || defined(OPENSSL_NO_NEXTPROTONEG)
 			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_NEXTPROTONEG)
+		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,
@@ -730,7 +754,16 @@ 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_NEXTPROTONEG)
 				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;
@@ -3467,4 +3500,72 @@ int ssl3_send_cert_status(SSL *s)
 	/* SSL3_ST_SW_CERT_STATUS_B */
 	return(ssl3_do_write(s,SSL3_RT_HANDSHAKE));
 	}
+
+# ifndef OPENSSL_NO_NEXTPROTONEG
+/* 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;
+	int 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,
+		514,  /* See the payload format below */
+		&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 3be36d6411..2d8ada2fdd 100644
--- a/ssl/ssl.h
+++ b/ssl/ssl.h
@@ -917,9 +917,28 @@ struct ssl_ctx_st
 	int (*tlsext_status_cb)(SSL *ssl, void *arg);
 	void *tlsext_status_arg;
 
+# ifndef OPENSSL_NO_NEXTPROTONEG
+	/* 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;
+
 	/* 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;
+# endif
 #endif
 
 #ifndef OPENSSL_NO_PSK
@@ -996,6 +1015,32 @@ 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_NEXTPROTONEG
+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
@@ -1260,6 +1305,19 @@ struct ssl_st
 	void *tls_session_secret_cb_arg;
 
 	SSL_CTX * initial_ctx; /* initial ctx, used to store sessions */
+
+#ifndef OPENSSL_NO_NEXTPROTONEG
+	/* 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
@@ -2046,6 +2104,7 @@ 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			 305
 #define SSL_F_SSL3_GET_RECORD				 143
 #define SSL_F_SSL3_GET_SERVER_CERTIFICATE		 144
 #define SSL_F_SSL3_GET_SERVER_DONE			 145
@@ -2250,6 +2309,8 @@ 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		 355
+#define SSL_R_GOT_NEXT_PROTO_WITHOUT_EXTENSION		 356
 #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 38c5cc29a6..bef479a55f 100644
--- a/ssl/ssl3.h
+++ b/ssl/ssl3.h
@@ -462,6 +462,11 @@ typedef struct ssl3_state_st
 	void *server_opaque_prf_input;
 	size_t server_opaque_prf_input_len;
 
+#ifndef OPENSSL_NO_NEXTPROTONEG
+	/* 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];
@@ -554,6 +559,8 @@ 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)
+#define SSL3_ST_CW_NEXT_PROTO_A		(0x200|SSL_ST_CONNECT)
+#define SSL3_ST_CW_NEXT_PROTO_B		(0x201|SSL_ST_CONNECT)
 #define SSL3_ST_CW_FINISHED_A		(0x1B0|SSL_ST_CONNECT)
 #define SSL3_ST_CW_FINISHED_B		(0x1B1|SSL_ST_CONNECT)
 /* read from server */
@@ -601,6 +608,8 @@ 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)
+#define SSL3_ST_SR_NEXT_PROTO_A		(0x210|SSL_ST_ACCEPT)
+#define SSL3_ST_SR_NEXT_PROTO_B		(0x211|SSL_ST_ACCEPT)
 #define SSL3_ST_SR_FINISHED_A		(0x1C0|SSL_ST_ACCEPT)
 #define SSL3_ST_SR_FINISHED_B		(0x1C1|SSL_ST_ACCEPT)
 /* write to client */
@@ -625,6 +634,7 @@ typedef struct ssl3_state_st
 #define SSL3_MT_CLIENT_KEY_EXCHANGE		16
 #define SSL3_MT_FINISHED			20
 #define SSL3_MT_CERTIFICATE_STATUS		22
+#define SSL3_MT_NEXT_PROTO			67
 #define DTLS1_MT_HELLO_VERIFY_REQUEST    3
 
 
diff --git a/ssl/ssl_err.c b/ssl/ssl_err.c
index 895b00a973..59721a63ea 100644
--- a/ssl/ssl_err.c
+++ b/ssl/ssl_err.c
@@ -1,6 +1,6 @@
 /* ssl/ssl_err.c */
 /* ====================================================================
- * Copyright (c) 1999-2010 The OpenSSL Project.  All rights reserved.
+ * Copyright (c) 1999-2011 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"},
@@ -362,6 +363,8 @@ 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 0a6cf3ad30..596d9b758b 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_NEXTPROTONEG
+	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_NEXTPROTONEG)
+	if (s->next_proto_negotiated)
+		OPENSSL_free(s->next_proto_negotiated);
+#endif
+
 	OPENSSL_free(s);
 	}
 
@@ -1494,6 +1502,123 @@ int SSL_get_servername_type(const SSL *s)
 		return TLSEXT_NAMETYPE_host_name;
 	return -1;
 	}
+
+# ifndef OPENSSL_NO_NEXTPROTONEG
+/* 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)
@@ -1666,6 +1791,10 @@ SSL_CTX *SSL_CTX_new(const SSL_METHOD *meth)
 	ret->tlsext_status_cb = 0;
 	ret->tlsext_status_arg = NULL;
 
+# ifndef OPENSSL_NO_NEXTPROTONEG
+	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 4bb64a4a2b..4d6ffd9f39 100644
--- a/ssl/ssl_locl.h
+++ b/ssl/ssl_locl.h
@@ -986,6 +986,9 @@ 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_NEXTPROTONEG
+int ssl3_send_next_proto(SSL *s);
+# endif
 #endif
 
 int dtls1_client_hello(SSL *s);
@@ -1004,6 +1007,9 @@ 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_NEXTPROTONEG
+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 d61fb8505c..032319bd76 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -617,6 +617,18 @@ unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned cha
 			i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
 		}
 
+#ifndef OPENSSL_NO_NEXTPROTONEG
+	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;
 
@@ -628,6 +640,9 @@ unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned cha
 	{
 	int extdatalen=0;
 	unsigned char *ret = p;
+#ifndef OPENSSL_NO_NEXTPROTONEG
+	int 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)
@@ -741,6 +756,28 @@ unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned cha
 
 		}
 
+#ifndef OPENSSL_NO_NEXTPROTONEG
+	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;
 
@@ -1147,6 +1184,28 @@ int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
 				else
 					s->tlsext_status_type = -1;
 			}
+#ifndef OPENSSL_NO_NEXTPROTONEG
+		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;
@@ -1170,6 +1229,26 @@ int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, in
 	return 1;
 	}
 
+#ifndef OPENSSL_NO_NEXTPROTONEG
+/* 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;
@@ -1304,6 +1383,39 @@ 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_NEXTPROTONEG
+		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 75ddfcad8d..14b5d9bfdf 100644
--- a/ssl/tls1.h
+++ b/ssl/tls1.h
@@ -223,6 +223,11 @@ extern "C" {
 /* Temporary extension type */
 #define TLSEXT_TYPE_renegotiate                 0xff01
 
+#ifndef OPENSSL_NO_NEXTPROTONEG
+/* 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 */
-- 
2.40.0