Commit b0d6f3c5 authored by Adam Langley's avatar Adam Langley
Browse files

Support ALPN. 

This change adds support for ALPN[1] in OpenSSL. ALPN is the IETF
blessed version of NPN and we'll be supporting both ALPN and NPN for
some time yet.

Cherry-picked from 6f017a8f.

[1] https://tools.ietf.org/html/draft-ietf-tls-applayerprotoneg-00
parent 03386484

apps/s_client.c

+39 −2
Original line number Diff line number Diff line
@@ -368,6 +368,7 @@ static void sc_usage(void) 
	BIO_printf(bio_err," -proof_debug      - request an audit proof and print its hex dump\n");

# ifndef OPENSSL_NO_NEXTPROTONEG

	BIO_printf(bio_err," -nextprotoneg arg - enable NPN extension, considering named protocols supported (comma-separated list)\n");

	BIO_printf(bio_err," -alpn arg         - enable ALPN extension, considering named protocols supported (comma-separated list)\n");

# endif

#ifndef OPENSSL_NO_TLSEXT

	BIO_printf(bio_err," -serverinfo types - send empty ClientHello extensions (comma-separated numbers)\n");
@@ -640,6 +641,7 @@ int MAIN(int argc, char **argv) 
        {NULL,0};

# ifndef OPENSSL_NO_NEXTPROTONEG

	const char *next_proto_neg_in = NULL;

	const char *alpn_in = NULL;

# endif

# define MAX_SI_TYPES 100

	unsigned short serverinfo_types[MAX_SI_TYPES];
@@ -988,6 +990,11 @@ static char *jpake_secret = NULL; 
			if (--argc < 1) goto bad;

			next_proto_neg_in = *(++argv);

			}

		else if (strcmp(*argv,"-alpn") == 0)

			{

			if (--argc < 1) goto bad;

			alpn_in = *(++argv);

			}

# endif

		else if (strcmp(*argv,"-serverinfo") == 0)

			{
@@ -1301,9 +1308,24 @@ bad: 
	 */

	if (socket_type == SOCK_DGRAM) SSL_CTX_set_read_ahead(ctx, 1);



#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)

#if !defined(OPENSSL_NO_TLSEXT)

# if !defined(OPENSSL_NO_NEXTPROTONEG)

	if (next_proto.data)

		SSL_CTX_set_next_proto_select_cb(ctx, next_proto_cb, &next_proto);

# endif

	if (alpn_in)

		{

		unsigned short alpn_len;

		unsigned char *alpn = next_protos_parse(&alpn_len, alpn_in);



		if (alpn == NULL)

			{

			BIO_printf(bio_err, "Error parsing -alpn argument\n");

			goto end;

			}

		SSL_CTX_set_alpn_protos(ctx, alpn, alpn_len);

		OPENSSL_free(alpn);

		}

#endif

#ifndef OPENSSL_NO_TLSEXT

		if (serverinfo_types_count)
@@ -2262,7 +2284,8 @@ static void print_stuff(BIO *bio, SSL *s, int full) 
	}

#endif



#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)

#if !defined(OPENSSL_NO_TLSEXT)

# if !defined(OPENSSL_NO_NEXTPROTONEG)

	if (next_proto.status != -1) {

		const unsigned char *proto;

		unsigned int proto_len;
@@ -2271,6 +2294,20 @@ static void print_stuff(BIO *bio, SSL *s, int full) 
		BIO_write(bio, proto, proto_len);

		BIO_write(bio, "\n", 1);

	}

	{

		const unsigned char *proto;

		unsigned int proto_len;

		SSL_get0_alpn_selected(s, &proto, &proto_len);

		if (proto_len > 0)

			{

			BIO_printf(bio, "ALPN protocol: ");

			BIO_write(bio, proto, proto_len);

			BIO_write(bio, "\n", 1);

			}

		else

			BIO_printf(bio, "No ALPN negotiated\n");

	}

# endif

#endif



 	{

apps/s_server.c

+66 −2
Original line number Diff line number Diff line
@@ -578,6 +578,7 @@ static void sv_usage(void) 
	BIO_printf(bio_err," -nextprotoneg arg - set the advertised protocols for the NPN extension (comma-separated list)\n");

# endif

        BIO_printf(bio_err," -use_srtp profiles - Offer SRTP key management with a colon-separated profile list\n");

	BIO_printf(bio_err," -alpn arg  - set the advertised protocols for the ALPN extension (comma-separated list)\n");

#endif

	BIO_printf(bio_err," -keymatexport label   - Export keying material using label\n");

	BIO_printf(bio_err," -keymatexportlen len  - Export len bytes of keying material (default 20)\n");
@@ -933,8 +934,47 @@ static int next_proto_cb(SSL *s, const unsigned char **data, unsigned int *len, 
	}

# endif  /* ndef OPENSSL_NO_NEXTPROTONEG */



/* This the context that we pass to alpn_cb */

typedef struct tlsextalpnctx_st {

	unsigned char *data;

	unsigned short len;

} tlsextalpnctx;



#endif

static int alpn_cb(SSL *s, const unsigned char **out, unsigned char *outlen, const unsigned char *in, unsigned int inlen, void *arg)

	{

	tlsextalpnctx *alpn_ctx = arg;



	if (!s_quiet)

		{

		/* We can assume that |in| is syntactically valid. */

		unsigned i;

		BIO_printf(bio_s_out, "ALPN protocols advertised by the client: ");

		for (i = 0; i < inlen; )

			{

			if (i)

				BIO_write(bio_s_out, ", ", 2);

			BIO_write(bio_s_out, &in[i + 1], in[i]);

			i += in[i] + 1;

			}

		BIO_write(bio_s_out, "\n", 1);

		}



	if (SSL_select_next_proto((unsigned char**) out, outlen, alpn_ctx->data, alpn_ctx->len, in, inlen) !=

	    OPENSSL_NPN_NEGOTIATED)

		{

		return SSL_TLSEXT_ERR_NOACK;

		}



	if (!s_quiet)

		{

		BIO_printf(bio_s_out, "ALPN protocols selected: ");

		BIO_write(bio_s_out, *out, *outlen);

		BIO_write(bio_s_out, "\n", 1);

		}



	return SSL_TLSEXT_ERR_OK;

	}

#endif  /* ndef OPENSSL_NO_TLSEXT */



int MAIN(int, char **);
@@ -984,6 +1024,8 @@ int MAIN(int argc, char *argv[]) 
# ifndef OPENSSL_NO_NEXTPROTONEG

	const char *next_proto_neg_in = NULL;

	tlsextnextprotoctx next_proto;

	const char *alpn_in = NULL;

	tlsextalpnctx alpn_ctx = { NULL, 0};

# endif

#endif

#ifndef OPENSSL_NO_PSK
@@ -1424,6 +1466,11 @@ int MAIN(int argc, char *argv[]) 
			if (--argc < 1) goto bad;

			next_proto_neg_in = *(++argv);

			}

		else if	(strcmp(*argv,"-alpn") == 0)

			{

			if (--argc < 1) goto bad;

			alpn_in = *(++argv);

			}

# endif

#endif

#if !defined(OPENSSL_NO_JPAKE) && !defined(OPENSSL_NO_PSK)
@@ -1551,7 +1598,8 @@ bad: 
#endif /* OPENSSL_NO_TLSEXT */

		}



#if !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG) 

#if !defined(OPENSSL_NO_TLSEXT)

# if !defined(OPENSSL_NO_NEXTPROTONEG) 

	if (next_proto_neg_in)

		{

		unsigned short len;
@@ -1565,6 +1613,16 @@ bad: 
		next_proto.data = NULL;

		}

# endif

	alpn_ctx.data = NULL;

	if (alpn_in)

		{

		unsigned short len;

		alpn_ctx.data = next_protos_parse(&len, alpn_in);

		if (alpn_ctx.data == NULL)

			goto end;

		alpn_ctx.len = len;

		}

#endif



	if (crl_file)

		{
@@ -1801,6 +1859,8 @@ bad: 
	if (next_proto.data)

		SSL_CTX_set_next_protos_advertised_cb(ctx, next_proto_cb, &next_proto);

# endif

	if (alpn_ctx.data)

		SSL_CTX_set_alpn_select_cb(ctx, alpn_cb, &alpn_ctx);

#endif 



#ifndef OPENSSL_NO_DH
@@ -2027,6 +2087,10 @@ end: 
		BIO_free(authz_in);

	if (serverinfo_in != NULL)

		BIO_free(serverinfo_in);

	if (next_proto.data)

		OPENSSL_free(next_proto.data);

	if (alpn_ctx.data)

		OPENSSL_free(alpn_ctx.data);

#endif

	ssl_excert_free(exc);

	if (ssl_args)

ssl/s3_lib.c

+13 −0
Original line number Diff line number Diff line
@@ -3002,6 +3002,11 @@ void ssl3_free(SSL *s) 
		BIO_free(s->s3->handshake_buffer);

	}

	if (s->s3->handshake_dgst) ssl3_free_digest_list(s);

#ifndef OPENSSL_NO_TLSEXT

	if (s->s3->alpn_selected)

		OPENSSL_free(s->s3->alpn_selected);

#endif



#ifndef OPENSSL_NO_SRP

	SSL_SRP_CTX_free(s);

#endif
@@ -3080,6 +3085,14 @@ void ssl3_clear(SSL *s) 
	if (s->s3->handshake_dgst) {

		ssl3_free_digest_list(s);

	}	



#if !defined(OPENSSL_NO_TLSEXT)

	if (s->s3->alpn_selected)

		{

		free(s->s3->alpn_selected);

		s->s3->alpn_selected = NULL;

		}

#endif

	memset(s->s3,0,sizeof *s->s3);

	s->s3->rbuf.buf = rp;

	s->s3->wbuf.buf = wp;

ssl/ssl.h

+45 −0
Original line number Diff line number Diff line
@@ -1097,6 +1097,31 @@ struct ssl_ctx_st 
				    void *arg);

	void *next_proto_select_cb_arg;

# endif



	/* ALPN information

	 * (we are in the process of transitioning from NPN to ALPN.) */



	/* For a server, this contains a callback function that allows the

	 * server to select the protocol for the connection.

	 *   out: on successful return, this must point to the raw protocol

	 *        name (without the length prefix).

	 *   outlen: on successful return, this contains the length of |*out|.

	 *   in: points to the client's list of supported protocols in

	 *       wire-format.

	 *   inlen: the length of |in|. */

	int (*alpn_select_cb)(SSL *s,

			      const unsigned char **out,

			      unsigned char *outlen,

			      const unsigned char* in,

			      unsigned int inlen,

			      void *arg);

	void *alpn_select_cb_arg;



	/* For a client, this contains the list of supported protocols in wire

	 * format. */

	unsigned char* alpn_client_proto_list;

	unsigned alpn_client_proto_list_len;



        /* SRTP profiles we are willing to do from RFC 5764 */

	STACK_OF(SRTP_PROTECTION_PROFILE) *srtp_profiles;

# ifndef OPENSSL_NO_EC
@@ -1195,6 +1220,21 @@ void SSL_get0_next_proto_negotiated(const SSL *s, 
#define OPENSSL_NPN_NO_OVERLAP	2

#endif



int SSL_CTX_set_alpn_protos(SSL_CTX *ctx, const unsigned char* protos,

			    unsigned protos_len);

int SSL_set_alpn_protos(SSL *ssl, const unsigned char* protos,

			unsigned protos_len);

void SSL_CTX_set_alpn_select_cb(SSL_CTX* ctx,

				int (*cb) (SSL *ssl,

					   const unsigned char **out,

					   unsigned char *outlen,

					   const unsigned char *in,

					   unsigned int inlen,

					   void *arg),

				void *arg);

void SSL_get0_alpn_selected(const SSL *ssl, const unsigned char **data,

			    unsigned *len);



#ifndef OPENSSL_NO_PSK

/* the maximum length of the buffer given to callbacks containing the

 * resulting identity/psk */
@@ -1501,6 +1541,11 @@ struct ssl_st 
	                                 */

	unsigned int tlsext_hb_pending; /* Indicates if a HeartbeatRequest is in flight */

	unsigned int tlsext_hb_seq;     /* HeartbeatRequest sequence number */



	/* For a client, this contains the list of supported protocols in wire

	 * format. */

	unsigned char* alpn_client_proto_list;

	unsigned alpn_client_proto_list_len;

#else

#define session_ctx ctx

#endif /* OPENSSL_NO_TLSEXT */

ssl/ssl3.h

+11 −1
Original line number Diff line number Diff line
@@ -580,7 +580,17 @@ typedef struct ssl3_state_st 
	 * as the types were received in the client hello. */

	unsigned short *tlsext_custom_types;

	size_t tlsext_custom_types_count; /* how many tlsext_custom_types */

#endif



	/* ALPN information

	 * (we are in the process of transitioning from NPN to ALPN.) */



	/* In a server these point to the selected ALPN protocol after the

	 * ClientHello has been processed. In a client these contain the

	 * protocol that the server selected once the ServerHello has been

	 * processed. */

	unsigned char *alpn_selected;

	unsigned alpn_selected_len;

#endif	/* OPENSSL_NO_TLSEXT */

	} SSL3_STATE;



#endif