Allow for conditional compilation of SSL 3.0 protocol

This allows to completely remove SSL 3.0 support by calling configure
with the '--disable-ssl3' option.

Resolves #93

20 files changed, 232 insertions, 75 deletions

diff --git a/NEWS b/NEWS
index b51b9aeaab..75293ab678 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,15 @@ Copyright (C) 2000-2016 Free Software Foundation, Inc.
 Copyright (C) 2013-2016 Nikos Mavrogiannopoulos
 See the end for copying conditions.
 
+* Version 3.5.1 (unreleased)
+
+** libgnutls: The SSL 3.0 protocol support can completely be removed
+   using a compile time option. The configure option is --disable-ssl3.
+
+** API and ABI modifications:
+No changes since last version.
+
+
 * Version 3.5.0 (released 2016-05-09)
 
 ** libgnutls: Added SHA3 based signing algorithms for DSA, RSA and ECDSA,
diff --git a/configure.ac b/configure.ac
index d6b17e98c9..67ff1e2d87 100644
--- a/configure.ac
+++ b/configure.ac
@@ -949,6 +949,7 @@ AC_MSG_NOTICE([Optional features:
 (note that included applications might not compile properly
 if features are disabled)
 
+  SSL3 support:         $ac_enable_ssl3
   DTLS-SRTP support:    $ac_enable_srtp
   ALPN support:         $ac_enable_alpn
   OCSP support:         $ac_enable_ocsp
diff --git a/lib/algorithms/ciphersuites.c b/lib/algorithms/ciphersuites.c
index 27a6a811d4..76964ae81c 100644
--- a/lib/algorithms/ciphersuites.c
+++ b/lib/algorithms/ciphersuites.c
@@ -30,6 +30,10 @@
 #include <auth/anon.h>
 #include <auth/psk.h>
 
+#ifndef ENABLE_SSL3
+# define GNUTLS_SSL3 GNUTLS_TLS1
+#endif
+
 /* Cipher SUITES */
 #define ENTRY( name, block_algorithm, kx_algorithm, mac_algorithm, min_version, dtls_version ) \
 	{ #name, name, block_algorithm, kx_algorithm, mac_algorithm, min_version, dtls_version, GNUTLS_MAC_SHA256}
diff --git a/lib/algorithms/protocols.c b/lib/algorithms/protocols.c
index 06eb5523ad..8ef69a5e70 100644
--- a/lib/algorithms/protocols.c
+++ b/lib/algorithms/protocols.c
@@ -27,13 +27,104 @@
 
 /* TLS Versions */
 static const version_entry_st sup_versions[] = {
-	{"SSL3.0", GNUTLS_SSL3, 0, 3, 0, GNUTLS_STREAM, 1, 0, 0, 0, 0, 1, 0},
-	{"TLS1.0", GNUTLS_TLS1, 1, 3, 1, GNUTLS_STREAM, 1, 0, 1, 0, 0, 0, 0},
-	{"TLS1.1", GNUTLS_TLS1_1, 2, 3, 2, GNUTLS_STREAM, 1, 1, 1, 0, 0, 0, 0},
-	{"TLS1.2", GNUTLS_TLS1_2, 3, 3, 3, GNUTLS_STREAM, 1, 1, 1, 1, 1, 0, 1},
-	{"DTLS0.9", GNUTLS_DTLS0_9, 200, 1, 0, GNUTLS_DGRAM, 1, 1, 1, 0, 0, 0, 0},	/* Cisco AnyConnect (based on about OpenSSL 0.9.8e) */
-	{"DTLS1.0", GNUTLS_DTLS1_0, 201, 254, 255, GNUTLS_DGRAM, 1, 1, 1, 0, 0, 0, 0},	/* 1.1 over datagram */
-	{"DTLS1.2", GNUTLS_DTLS1_2, 202, 254, 253, GNUTLS_DGRAM, 1, 1, 1, 1, 1, 0, 1},	/* 1.2 over datagram */
+	{.name = "SSL3.0", 
+	 .id = GNUTLS_SSL3,
+	 .age = 0,
+	 .major = 3,
+	 .minor = 0,
+	 .transport = GNUTLS_STREAM,
+	 .supported = 1,
+	 .explicit_iv = 0,
+	 .extensions = 0,
+	 .selectable_sighash = 0,
+	 .selectable_prf = 0,
+	 .obsolete = 1,
+	 .false_start = 0
+	},
+	{.name = "TLS1.0", 
+	 .id = GNUTLS_TLS1,
+	 .age = 1,
+	 .major = 3,
+	 .minor = 1,
+	 .transport = GNUTLS_STREAM,
+	 .supported = 1,
+	 .explicit_iv = 0,
+	 .extensions = 1,
+	 .selectable_sighash = 0,
+	 .selectable_prf = 0,
+	 .obsolete = 0,
+	 .false_start = 0
+	},
+	{.name = "TLS1.1", 
+	 .id = GNUTLS_TLS1_1,
+	 .age = 2,
+	 .major = 3,
+	 .minor = 2,
+	 .transport = GNUTLS_STREAM,
+	 .supported = 1,
+	 .explicit_iv = 1,
+	 .extensions = 1,
+	 .selectable_sighash = 0,
+	 .selectable_prf = 0,
+	 .obsolete = 0,
+	 .false_start = 0
+	},
+	{.name = "TLS1.2", 
+	 .id = GNUTLS_TLS1_2,
+	 .age = 3,
+	 .major = 3,
+	 .minor = 3,
+	 .transport = GNUTLS_STREAM,
+	 .supported = 1,
+	 .explicit_iv = 1,
+	 .extensions = 1,
+	 .selectable_sighash = 1,
+	 .selectable_prf = 1,
+	 .obsolete = 0,
+	 .false_start = 1
+	},
+	{.name = "DTLS0.9", /* Cisco AnyConnect (based on about OpenSSL 0.9.8e) */
+	 .id = GNUTLS_DTLS0_9,
+	 .age = 200,
+	 .major = 1,
+	 .minor = 0,
+	 .transport = GNUTLS_DGRAM,
+	 .supported = 1,
+	 .explicit_iv = 1,
+	 .extensions = 1,
+	 .selectable_sighash = 0,
+	 .selectable_prf = 0,
+	 .obsolete = 0,
+	 .false_start = 0
+	},
+	{.name = "DTLS1.0", 
+	 .id = GNUTLS_DTLS1_0,
+	 .age = 201,
+	 .major = 254,
+	 .minor = 255,
+	 .transport = GNUTLS_DGRAM,
+	 .supported = 1,
+	 .explicit_iv = 1,
+	 .extensions = 1,
+	 .selectable_sighash = 0,
+	 .selectable_prf = 0,
+	 .obsolete = 0,
+	 .false_start = 0
+	},
+	{.name = "DTLS1.2", 
+	 .id = GNUTLS_DTLS1_2,
+	 .age = 202,
+	 .major = 254,
+	 .minor = 253,
+	 .transport = GNUTLS_DGRAM,
+	 .supported = 1,
+	 .explicit_iv = 1,
+	 .extensions = 1,
+	 .selectable_sighash = 1,
+	 .selectable_prf = 1,
+	 .obsolete = 0,
+	 .false_start = 1
+	},
 	{0, 0, 0, 0, 0}
 };
 
@@ -255,9 +346,15 @@ _gnutls_version_is_supported(gnutls_session_t session,
 {
 	int ret = 0;
 
-	GNUTLS_VERSION_ALG_LOOP(
-		ret = p->supported && p->transport == session->internals.transport
-	);
+	GNUTLS_VERSION_LOOP(
+		if(p->id == version) {
+#ifndef ENABLE_SSL3
+			if (p->obsolete != 0) return 0;
+#endif
+			ret = p->supported && p->transport == session->internals.transport;
+			break;
+		}
+	)
 
 	if (ret == 0)
 		return 0;
diff --git a/lib/auth/rsa.c b/lib/auth/rsa.c
index 4260b945ca..505fbee1dd 100644
--- a/lib/auth/rsa.c
+++ b/lib/auth/rsa.c
@@ -147,13 +147,16 @@ proc_rsa_client_kx(gnutls_session_t session, uint8_t * data,
 	ssize_t data_size = _data_size;
 	gnutls_datum_t rndkey = {NULL, 0};
 
+#ifdef ENABLE_SSL3
 	if (get_num_version(session) == GNUTLS_SSL3) {
 		/* SSL 3.0 
 		 */
 		ciphertext.data = data;
 		ciphertext.size = data_size;
-	} else {
-		/* TLS 1.0
+	} else
+#endif
+	{
+		/* TLS 1.0+
 		 */
 		DECR_LEN(data_size, 2);
 		ciphertext.data = &data[2];
@@ -298,12 +301,15 @@ _gnutls_gen_rsa_client_kx(gnutls_session_t session,
 		return gnutls_assert_val(ret);
 
 
+#ifdef ENABLE_SSL3
 	if (get_num_version(session) == GNUTLS_SSL3) {
 		/* SSL 3.0 */
 		_gnutls_buffer_replace_data(data, &sdata);
 
 		return data->length;
-	} else {		/* TLS 1 */
+	} else
+#endif
+	{		/* TLS 1.x */
 		ret =
 		    _gnutls_buffer_append_data_prefix(data, 16, sdata.data,
 						      sdata.size);
@@ -311,5 +317,4 @@ _gnutls_gen_rsa_client_kx(gnutls_session_t session,
 		_gnutls_free_datum(&sdata);
 		return ret;
 	}
-
 }
diff --git a/lib/cipher_int.c b/lib/cipher_int.c
index 67c46776c3..4e3e50373a 100644
--- a/lib/cipher_int.c
+++ b/lib/cipher_int.c
@@ -173,7 +173,8 @@ int _gnutls_auth_cipher_init(auth_cipher_hd_st * handle,
 			     const mac_entry_st * me,
 			     const gnutls_datum_t * mac_key,
 			     unsigned etm,
-			     unsigned ssl_hmac, int enc)
+			     unsigned ssl_hmac,
+			     int enc)
 {
 	int ret;
 
@@ -197,6 +198,7 @@ int _gnutls_auth_cipher_init(auth_cipher_hd_st * handle,
 
 	if (me->id != GNUTLS_MAC_AEAD) {
 		handle->is_mac = 1;
+#ifdef ENABLE_SSL3
 		handle->ssl_hmac = ssl_hmac;
 
 		if (ssl_hmac)
@@ -205,6 +207,7 @@ int _gnutls_auth_cipher_init(auth_cipher_hd_st * handle,
 						  mac_key->data,
 						  mac_key->size);
 		else
+#endif
 			ret =
 			    _gnutls_mac_init(&handle->mac.mac, me,
 					     mac_key->data, mac_key->size);
@@ -230,7 +233,8 @@ int _gnutls_auth_cipher_init(auth_cipher_hd_st * handle,
 
 }
 
-#define MAC(handle, text, textlen) \
+#ifdef ENABLE_SSL3
+# define MAC(handle, text, textlen) \
 		if (handle->ssl_hmac) { \
 			ret = \
 			    _gnutls_hash(&handle->mac.dig, text, textlen); \
@@ -239,6 +243,12 @@ int _gnutls_auth_cipher_init(auth_cipher_hd_st * handle,
 		} \
 		if (unlikely(ret < 0)) \
 			return gnutls_assert_val(ret)
+#else
+# define MAC(handle, text, textlen) \
+		ret = _gnutls_mac(&handle->mac.mac, text, textlen); \
+		if (unlikely(ret < 0)) \
+			return gnutls_assert_val(ret)
+#endif
 
 int _gnutls_auth_cipher_add_auth(auth_cipher_hd_st * handle,
 				 const void *text, int textlen)
@@ -404,17 +414,18 @@ int _gnutls_auth_cipher_decrypt2(auth_cipher_hd_st * handle,
 int _gnutls_auth_cipher_tag(auth_cipher_hd_st * handle, void *tag,
 			    int tag_size)
 {
-	int ret;
-
 	if (handle->is_mac) {
+#ifdef ENABLE_SSL3
+		int ret;
+
 		if (handle->ssl_hmac) {
 			ret =
 			    _gnutls_mac_output_ssl3(&handle->mac.dig, tag);
 			if (ret < 0)
 				return gnutls_assert_val(ret);
-		} else {
+		} else
+#endif
 			_gnutls_mac_output(&handle->mac.mac, tag);
-		}
 	} else if (_gnutls_cipher_is_aead(&handle->cipher)) {
 		_gnutls_cipher_tag(&handle->cipher, tag, tag_size);
 	} else
@@ -426,9 +437,11 @@ int _gnutls_auth_cipher_tag(auth_cipher_hd_st * handle, void *tag,
 void _gnutls_auth_cipher_deinit(auth_cipher_hd_st * handle)
 {
 	if (handle->is_mac) {
+#ifdef ENABLE_SSL3
 		if (handle->ssl_hmac)	/* failure here doesn't matter */
 			_gnutls_mac_deinit_ssl3(&handle->mac.dig, NULL);
 		else
+#endif
 			_gnutls_mac_deinit(&handle->mac.mac, NULL);
 	}
 	if (handle->non_null != 0)
diff --git a/lib/cipher_int.h b/lib/cipher_int.h
index b2dd763d22..a7415757b5 100644
--- a/lib/cipher_int.h
+++ b/lib/cipher_int.h
@@ -193,7 +193,9 @@ typedef struct {
 		mac_hd_st mac;
 	} mac;
 	unsigned int is_mac:1;
+#ifdef ENABLE_SSL3
 	unsigned int ssl_hmac:1;
+#endif
 	unsigned int non_null:1;
 	unsigned int etm:1;
 	size_t tag_size;
diff --git a/lib/constate.c b/lib/constate.c
index 22ac8a30f2..4c4fa3dfc5 100644
--- a/lib/constate.c
+++ b/lib/constate.c
@@ -85,20 +85,21 @@ _gnutls_set_keys(gnutls_session_t session, record_parameters_st * params,
 	       session->security_parameters.server_random,
 	       GNUTLS_RANDOM_SIZE);
 
+#ifdef ENABLE_SSL3
 	if (get_num_version(session) == GNUTLS_SSL3) {	/* SSL 3 */
 		ret =
 		    _gnutls_ssl3_generate_random
 		    (session->security_parameters.master_secret,
 		     GNUTLS_MASTER_SIZE, rnd, 2 * GNUTLS_RANDOM_SIZE,
 		     block_size, key_block);
-	} else {		/* TLS 1.0 */
+	} else /* TLS 1.0+ */
+#endif
 		ret =
 		    _gnutls_PRF(session,
 				session->security_parameters.master_secret,
 				GNUTLS_MASTER_SIZE, keyexp, keyexp_length,
 				rnd, 2 * GNUTLS_RANDOM_SIZE, block_size,
 				key_block);
-	}
 
 	if (ret < 0)
 		return gnutls_assert_val(ret);
diff --git a/lib/ext/ext_master_secret.c b/lib/ext/ext_master_secret.c
index 0dc0b820fe..b5a1df38b5 100644
--- a/lib/ext/ext_master_secret.c
+++ b/lib/ext/ext_master_secret.c
@@ -67,6 +67,7 @@ _gnutls_ext_master_secret_recv_params(gnutls_session_t session,
 		return gnutls_assert_val(GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER);
 	}
 
+#ifdef ENABLE_SSL3
 	if (session->security_parameters.entity == GNUTLS_CLIENT) {
 		const version_entry_st *ver = get_version(session);
 
@@ -75,9 +76,9 @@ _gnutls_ext_master_secret_recv_params(gnutls_session_t session,
 
 		if (ver->id != GNUTLS_SSL3)
 			session->security_parameters.ext_master_secret = 1;
-	} else {
+	} else
+#endif
 		session->security_parameters.ext_master_secret = 1;
-	}
 
 	return 0;
 }
@@ -95,6 +96,7 @@ _gnutls_ext_master_secret_send_params(gnutls_session_t session,
 	}
 
 	/* this function sends the client extension data */
+#ifdef ENABLE_SSL3
 	if (session->security_parameters.entity == GNUTLS_CLIENT) {
 		if (session->internals.priorities.protocol.algorithms == 1 &&
 		    session->internals.priorities.protocol.priority[0] == GNUTLS_SSL3)
@@ -110,7 +112,14 @@ _gnutls_ext_master_secret_send_params(gnutls_session_t session,
 			return GNUTLS_E_INT_RET_0;
 	}
 
+
+	return 0;
+#else
+	if (session->security_parameters.entity == GNUTLS_CLIENT ||
+	    session->security_parameters.ext_master_secret != 0) 
+		return GNUTLS_E_INT_RET_0;
 	return 0;
+#endif
 }
 
 /**
diff --git a/lib/gnutls_int.h b/lib/gnutls_int.h
index 74225378d9..744261ffc2 100644
--- a/lib/gnutls_int.h
+++ b/lib/gnutls_int.h
@@ -490,7 +490,10 @@ typedef struct {
 	bool extensions;	/* whether it supports extensions */
 	bool selectable_sighash;	/* whether signatures can be selected */
 	bool selectable_prf;	/* whether the PRF is ciphersuite-defined */
-	bool obsolete;		/* Do not use this protocol version as record version */
+
+	/* if SSL3 is disabled this flag indicates that this protocol is a placeholder,
+	 * otherwise it prevents this protocol from being set as record version */
+	bool obsolete;
 	bool false_start;	/* That version can be used with false start */
 } version_entry_st;
 
diff --git a/lib/handshake.c b/lib/handshake.c
index 5e04f5a3bf..0f65a67c2c 100644
--- a/lib/handshake.c
+++ b/lib/handshake.c
@@ -265,6 +265,7 @@ int _gnutls_set_server_random(gnutls_session_t session, uint8_t * rnd)
 	return 0;
 }
 
+#ifdef ENABLE_SSL3
 /* Calculate The SSL3 Finished message
  */
 #define SSL3_CLIENT_MSG "CLNT"
@@ -328,6 +329,7 @@ _gnutls_ssl3_finished(gnutls_session_t session, int type, uint8_t * ret,
 
 	return 0;
 }
+#endif
 
 /* Hash the handshake messages as required by TLS 1.0
  */
@@ -693,6 +695,7 @@ static int _gnutls_send_finished(gnutls_session_t session, int again)
 		if (unlikely(vers == NULL))
 			return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
 
+#ifdef ENABLE_SSL3
 		if (vers->id == GNUTLS_SSL3) {
 			ret =
 			    _gnutls_ssl3_finished(session,
@@ -701,12 +704,15 @@ static int _gnutls_send_finished(gnutls_session_t session, int again)
 						  entity, data, 1);
 			_mbuffer_set_udata_size(bufel, 36);
 		} else {	/* TLS 1.0+ */
+#endif
 			ret = _gnutls_finished(session,
 					       session->
 					       security_parameters.entity,
 					       data, 1);
 			_mbuffer_set_udata_size(bufel, 12);
+#ifdef ENABLE_SSL3
 		}
+#endif
 
 		if (ret < 0) {
 			gnutls_assert();
@@ -776,9 +782,11 @@ static int _gnutls_recv_finished(gnutls_session_t session)
 	vrfy = buf.data;
 	vrfy_size = buf.length;
 
+#ifdef ENABLE_SSL3
 	if (vers->id == GNUTLS_SSL3)
 		data_size = 36;
 	else
+#endif
 		data_size = 12;
 
 	if (vrfy_size != data_size) {
@@ -787,17 +795,18 @@ static int _gnutls_recv_finished(gnutls_session_t session)
 		goto cleanup;
 	}
 
+#ifdef ENABLE_SSL3
 	if (vers->id == GNUTLS_SSL3) {
 		ret =
 		    _gnutls_ssl3_finished(session,
 					  (session->security_parameters.
 					   entity + 1) % 2, data, 0);
-	} else {		/* TLS 1.0 */
+	} else /* TLS 1.0+ */
+#endif
 		ret =
 		    _gnutls_finished(session,
 				     (session->security_parameters.entity +
 				      1) % 2, data, 0);
-	}
 
 	if (ret < 0) {
 		gnutls_assert();
@@ -899,6 +908,7 @@ _gnutls_server_select_suite(gnutls_session_t session, uint8_t * data,
 							 */
 
 	for (i = 0; i < datalen; i += 2) {
+#ifdef ENABLE_SSL3 /* No need to support certain SCSV's without SSL 3.0 */
 		/* TLS_RENEGO_PROTECTION_REQUEST = { 0x00, 0xff } */
 		if (session->internals.priorities.sr != SR_DISABLED &&
 		    data[i] == GNUTLS_RENEGO_PROTECTION_REQUEST_MAJOR &&
@@ -912,6 +922,7 @@ _gnutls_server_select_suite(gnutls_session_t session, uint8_t * data,
 				return retval;
 			}
 		}
+#endif
 
 		/* TLS_FALLBACK_SCSV */
 		if (data[i] == GNUTLS_FALLBACK_SCSV_MAJOR &&
@@ -1869,6 +1880,7 @@ copy_ciphersuites(gnutls_session_t session,
 		    gnutls_assert_val(GNUTLS_E_INSUFFICIENT_CREDENTIALS);
 
 	cipher_suites_size = ret;
+#ifdef ENABLE_SSL3
 	if (add_scsv) {
 		cipher_suites[cipher_suites_size] = 0x00;
 		cipher_suites[cipher_suites_size + 1] = 0xff;
@@ -1878,6 +1890,7 @@ copy_ciphersuites(gnutls_session_t session,
 		if (ret < 0)
 			return gnutls_assert_val(ret);
 	}
+#endif
 
 	if (session->internals.priorities.fallback) {
 		cipher_suites[cipher_suites_size] =
@@ -1977,7 +1990,7 @@ static int send_client_hello(gnutls_session_t session, int again)
 
 		if (hver == NULL) {
 			gnutls_assert();
-			return GNUTLS_E_INTERNAL_ERROR;
+			return GNUTLS_E_NO_PRIORITIES_WERE_SET;
 		}
 
 		if (unlikely(session->internals.default_hello_version[0] != 0)) {
@@ -2001,8 +2014,8 @@ static int send_client_hello(gnutls_session_t session, int again)
 			return gnutls_assert_val(GNUTLS_E_UNSUPPORTED_VERSION_PACKET);
 
 		if (session->internals.priorities.min_record_version != 0) {
-			/* Advertize the SSL 3.0 record packet version in
-			 * record packets during the handshake.
+			/* Advertize the lowest supported (SSL 3.0) record packet
+			 * version in record packets during the handshake.
 			 * That is to avoid confusing implementations
 			 * that do not support TLS 1.2 and don't know
 			 * how 3,3 version of record packets look like.
@@ -2011,7 +2024,7 @@ static int send_client_hello(gnutls_session_t session, int again)
 
 			if (v == NULL) {
 				gnutls_assert();
-				return GNUTLS_E_INTERNAL_ERROR;
+				return GNUTLS_E_NO_PRIORITIES_WERE_SET;
 			} else {
 				_gnutls_record_set_default_version(session,
 								   v->major, v->minor);
@@ -2063,8 +2076,9 @@ static int send_client_hello(gnutls_session_t session, int again)
 		}
 
 		/* Copy the ciphersuites.
-		 *
-		 * If using SSLv3 Send TLS_RENEGO_PROTECTION_REQUEST SCSV for MITM
+		 */
+#ifdef ENABLE_SSL3
+		/* If using SSLv3 Send TLS_RENEGO_PROTECTION_REQUEST SCSV for MITM
 		 * prevention on initial negotiation (but not renegotiation; that's
 		 * handled with the RI extension below).
 		 */
@@ -2079,6 +2093,7 @@ static int send_client_hello(gnutls_session_t session, int again)
 				_gnutls_extension_list_add(session,
 						   GNUTLS_EXTENSION_SAFE_RENEGOTIATION);
 		} else
+#endif
 			ret =
 			    copy_ciphersuites(session, &extdata,
 					      FALSE);
diff --git a/lib/hash_int.c b/lib/hash_int.c
index 5201a16843..efcbf9093f 100644
--- a/lib/hash_int.c
+++ b/lib/hash_int.c
@@ -252,6 +252,7 @@ void _gnutls_mac_deinit(mac_hd_st * handle, void *digest)
 	handle->handle = NULL;
 }
 
+#ifdef ENABLE_SSL3
 inline static int get_padsize(gnutls_mac_algorithm_t algorithm)
 {
 	switch (algorithm) {
@@ -532,3 +533,5 @@ _gnutls_ssl3_generate_random(void *secret, int secret_len,
 
 	return 0;
 }
+
+#endif
diff --git a/lib/hash_int.h b/lib/hash_int.h
index 9ebd3fce2b..4d0244e91a 100644
--- a/lib/hash_int.h
+++ b/lib/hash_int.h
@@ -126,7 +126,8 @@ int
 _gnutls_hash_fast(gnutls_digest_algorithm_t algorithm,
 		  const void *text, size_t textlen, void *digest);
 
-/* help functions */
+#ifdef ENABLE_SSL3
+/* helper functions */
 int _gnutls_mac_init_ssl3(digest_hd_st *, const mac_entry_st * e,
 			  void *key, int keylen);
 int _gnutls_mac_deinit_ssl3(digest_hd_st * handle, void *digest);
@@ -141,6 +142,7 @@ int _gnutls_ssl3_hash_md5(const void *first, int first_len,
 
 int _gnutls_mac_deinit_ssl3_handshake(digest_hd_st * handle, void *digest,
 				      uint8_t * key, uint32_t key_size);
+#endif
 
 inline static int IS_SHA(gnutls_digest_algorithm_t algo)
 {
diff --git a/lib/kx.c b/lib/kx.c
index 2c9197a4fc..328fab645b 100644
--- a/lib/kx.c
+++ b/lib/kx.c
@@ -126,6 +126,7 @@ generate_normal_master(gnutls_session_t session,
 		       session->security_parameters.server_random,
 		       GNUTLS_RANDOM_SIZE);
 
+#ifdef ENABLE_SSL3
 		if (get_num_version(session) == GNUTLS_SSL3) {
 			ret =
 			    _gnutls_ssl3_generate_random(premaster->data,
@@ -134,7 +135,8 @@ generate_normal_master(gnutls_session_t session,
 							 GNUTLS_MASTER_SIZE,
 							 session->security_parameters.
 							 master_secret);
-		} else {
+		} else
+#endif
 			ret =
 			    _gnutls_PRF(session, premaster->data, premaster->size,
 					MASTER_SECRET, MASTER_SECRET_SIZE,
@@ -142,7 +144,6 @@ generate_normal_master(gnutls_session_t session,
 					GNUTLS_MASTER_SIZE,
 					session->security_parameters.
 					master_secret);
-		}
 	} else {
 		gnutls_datum_t shash = {NULL, 0};
 
diff --git a/lib/tls-sig.c b/lib/tls-sig.c
index f5f470afb9..492188a12f 100644
--- a/lib/tls-sig.c
+++ b/lib/tls-sig.c
@@ -469,6 +469,7 @@ _gnutls_handshake_verify_crt_vrfy(gnutls_session_t session,
 		     session->internals.handshake_hash_buffer.data,
 		     session->internals.handshake_hash_buffer_prev_len);
 
+#ifdef ENABLE_SSL3
 	if (ver->id == GNUTLS_SSL3) {
 		ret = _gnutls_generate_master(session, 1);
 		if (ret < 0) {
@@ -495,9 +496,12 @@ _gnutls_handshake_verify_crt_vrfy(gnutls_session_t session,
 			return gnutls_assert_val(ret);
 		}
 	} else {
+#endif
 		_gnutls_hash_deinit(&td_md5, concat);
 		_gnutls_hash_deinit(&td_sha, &concat[16]);
+#ifdef ENABLE_SSL3
 	}
+#endif
 
 	dconcat.data = concat;
 	dconcat.size = 20 + 16;	/* md5+ sha */
@@ -610,6 +614,7 @@ _gnutls_handshake_sign_crt_vrfy(gnutls_session_t session,
 		     session->internals.handshake_hash_buffer.data,
 		     session->internals.handshake_hash_buffer.length);
 
+#ifdef ENABLE_SSL3
 	if (ver->id == GNUTLS_SSL3) {
 		ret = _gnutls_generate_master(session, 1);
 		if (ret < 0) {
@@ -626,6 +631,7 @@ _gnutls_handshake_sign_crt_vrfy(gnutls_session_t session,
 		if (ret < 0)
 			return gnutls_assert_val(ret);
 	} else
+#endif
 		_gnutls_hash_deinit(&td_sha, &concat[16]);
 
 	/* ensure 1024 bit DSA keys are used */
@@ -648,6 +654,7 @@ _gnutls_handshake_sign_crt_vrfy(gnutls_session_t session,
 			     session->internals.handshake_hash_buffer.
 			     length);
 
+#ifdef ENABLE_SSL3
 		if (ver->id == GNUTLS_SSL3) {
 			ret =
 			    _gnutls_mac_deinit_ssl3_handshake(&td_md5,
@@ -658,6 +665,7 @@ _gnutls_handshake_sign_crt_vrfy(gnutls_session_t session,
 			if (ret < 0)
 				return gnutls_assert_val(ret);
 		} else
+#endif
 			_gnutls_hash_deinit(&td_md5, concat);
 
 		dconcat.data = concat;
diff --git a/m4/hooks.m4 b/m4/hooks.m4
index ca049fd012..9d057951d9 100644
--- a/m4/hooks.m4
+++ b/m4/hooks.m4
@@ -140,6 +140,21 @@ LIBTASN1_MINIMUM=4.3
     AC_MSG_WARN([C99 macros not supported. This may affect compiling.])
   ])
 
+  ac_enable_ssl3=yes
+  AC_MSG_CHECKING([whether to disable the SSL 3.0 protocol])
+  AC_ARG_ENABLE(ssl3-support,
+    AS_HELP_STRING([--disable-ssl3-support],
+                   [disable support for the SSL 3.0 protocol]),
+    ac_enable_ssl3=$enableval)
+  if test x$ac_enable_ssl3 != xno; then
+   AC_MSG_RESULT(no)
+   AC_DEFINE([ENABLE_SSL3], 1, [enable SSL3.0 support])
+  else
+   ac_full=0
+   AC_MSG_RESULT(yes)
+  fi
+  AM_CONDITIONAL(ENABLE_SSL3, test "$ac_enable_ssl3" != "no")
+
   ac_enable_srtp=yes
   AC_MSG_CHECKING([whether to disable DTLS-SRTP extension])
   AC_ARG_ENABLE(dtls-srtp-support,
diff --git a/tests/suite/Makefile.am b/tests/suite/Makefile.am
index 1dab4fbd3d..f3673717f9 100644
--- a/tests/suite/Makefile.am
+++ b/tests/suite/Makefile.am
@@ -105,6 +105,10 @@ if ENABLE_NON_SUITEB_CURVES
 TESTS_ENVIRONMENT += ENABLE_NON_SUITEB_CURVES=1
 endif
 
+if ENABLE_SSL3
+TESTS_ENVIRONMENT += ENABLE_SSL3=1
+endif
+
 if ENABLE_DANE
 nodist_check_SCRIPTS += testdane.sh
 endif
diff --git a/tests/suite/testcompat-main-openssl b/tests/suite/testcompat-main-openssl
index 224a2a068d..d6b53e0a26 100755
--- a/tests/suite/testcompat-main-openssl
+++ b/tests/suite/testcompat-main-openssl
@@ -88,7 +88,7 @@ for ADD in "" ":%COMPAT" ":%NO_ETM"; do #":%NO_TICKETS" ":%DISABLE_SAFE_RENEGOTI
 		echo "** Modifier: ${ADD}"
 	fi
 
-	if test "${HAVE_SSL3}" != 1; then
+	if test "${HAVE_SSL3}" != 1 && test "{ENABLE_SSL3}" = 1; then
 		# It seems debian disabled SSL 3.0 completely on openssl
 
 		eval "${GETPORT}"
@@ -423,7 +423,7 @@ for ADD in "" ":%COMPAT" ":%NO_ETM" ":%NO_TICKETS" ":%DISABLE_SAFE_RENEGOTIATION
 		echo "** Modifier: ${ADD}"
 	fi
 
-	if test "${HAVE_SSL3}" != 1; then
+	if test "${HAVE_SSL3}" != 1 && test "{ENABLE_SSL3}" = 1; then
 
 		echo "Check SSL 3.0 with RSA ciphersuite"
 		eval "${GETPORT}"
diff --git a/tests/suite/testcompat-main-polarssl b/tests/suite/testcompat-main-polarssl
index a004f710c3..0286cb0d63 100755
--- a/tests/suite/testcompat-main-polarssl
+++ b/tests/suite/testcompat-main-polarssl
@@ -93,43 +93,6 @@ for ADD in "" ":%COMPAT" ":%NO_ETM"; do #":%NO_TICKETS" ":%DISABLE_SAFE_RENEGOTI
 
 	eval "${GETPORT}"
 
-	# SSL 3.0 is disabled in debian's polarssl
-	if test 0 = 1; then
-		echo "Check SSL 3.0 with RSA ciphersuite"
-		launch_server $$  --priority "NONE:+CIPHER-ALL:+SIGN-ALL:+COMP-NULL:+MAC-ALL:+VERS-SSL3.0:+RSA${ADD}" --x509certfile "${SERV_CERT}" --x509keyfile "${SERV_KEY}" --x509cafile "${CA_CERT}" --dhparams "${srcdir}/params.dh"
-		PID=$!
-		wait_server ${PID}
-
-		"${POLARSSL_CLI}" server_port="${PORT}" server_name=localhost max_version=ssl3 crt_file="${CLI_CERT}" key_file="${CLI_KEY}" ca_file="${CA_CERT}" </dev/null >>"${LOGFILE}" 2>&1 || \
-			fail ${PID} "Failed"
-
-		kill ${PID}
-		wait
-
-		echo "Check SSL 3.0 with DHE-RSA ciphersuite"
-		launch_server $$  --priority "NONE:+CIPHER-ALL:+SIGN-ALL:+COMP-NULL:+MAC-ALL:+VERS-SSL3.0:+DHE-RSA${ADD}" --x509certfile "${SERV_CERT}" --x509keyfile "${SERV_KEY}" --x509cafile "${CA_CERT}" --dhparams "${srcdir}/params.dh"
-		PID=$!
-		wait_server ${PID}
-
-		"${POLARSSL_CLI}" server_name=localhost server_port="${PORT}" max_version=ssl3 crt_file="${CLI_CERT}" key_file="${CLI_KEY}" ca_file="${CA_CERT}" </dev/null >>"${LOGFILE}" 2>&1 || \
-			fail ${PID} "Failed"
-
-		kill ${PID}
-		wait
-
-		# No DSS for polarssl
-		#echo "Check SSL 3.0 with DHE-DSS ciphersuite"
-		#launch_server $$  --priority "NONE:+CIPHER-ALL:+SIGN-ALL:+COMP-NULL:+MAC-ALL:+VERS-SSL3.0:+DHE-DSS" --x509certfile "${SERV_DSA_CERT}" --x509keyfile "${SERV_DSA_KEY}" --dhparams "${srcdir}/params.dh"
-		#PID=$!
-		#wait_server ${PID}
-
-		#"${POLARSSL_CLI}" server_name=localhost server_port="${PORT}" max_version=ssl3 crt_file="${CLI_CERT}" key_file="${CLI_KEY}" ca_file="${CA_CERT}" </dev/null >>"${LOGFILE}" 2>&1 || \
-		#  fail ${PID} "Failed"
-		#
-		#kill ${PID}
-		#wait
-	fi
-
 	#TLS 1.0
 
 	echo "Check TLS 1.0 with DHE-RSA ciphersuite"
diff --git a/tests/version-checks.c b/tests/version-checks.c
index 7c5b467b20..a3f7089c62 100644
--- a/tests/version-checks.c
+++ b/tests/version-checks.c
@@ -139,7 +139,9 @@ void doit(void)
 	reset_buffers();
 	try("NORMAL:-VERS-TLS-ALL:+VERS-TLS1.2", GNUTLS_TLS1_2);
 	reset_buffers();
+#ifdef ENABLE_SSL3
 	try("NORMAL:-VERS-TLS-ALL:+VERS-SSL3.0", -1);
 	reset_buffers();
+#endif
 	gnutls_global_deinit();
 }