X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=ssl%2Ft1_lib.c;h=b3166d6254415aa9e0a8dec6c53c33a1539aa3ee;hb=d47c01a31a67ff4370b1883a58cabd0279752bb4;hp=46b3a4c9f903f285d105b2f88e34e056d1319e0d;hpb=0f39bab0df4109bab7effc7428e1d759f36d8642;p=oweals%2Fopenssl.git

diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 46b3a4c9f9..b3166d6254 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -241,6 +241,12 @@ static const unsigned char eccurves_default[] =
 		0,17, /* secp160r2 (17) */ 
 	};
 
+static const unsigned char suiteb_curves[] =
+	{
+		0, TLSEXT_curve_P_256,
+		0, TLSEXT_curve_P_384
+	};
+
 int tls1_ec_curve_id2nid(int curve_id)
 	{
 	/* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */
@@ -320,22 +326,74 @@ static void tls1_get_curvelist(SSL *s, int sess,
 		{
 		*pcurves = s->session->tlsext_ellipticcurvelist;
 		*pcurveslen = s->session->tlsext_ellipticcurvelist_length;
+		return;
 		}
-	else
+	/* For Suite B mode only include P-256, P-384 */
+	switch (tls1_suiteb(s))
 		{
+	case SSL_CERT_FLAG_SUITEB_128_LOS:
+		*pcurves = suiteb_curves;
+		*pcurveslen = sizeof(suiteb_curves);
+		break;
+
+	case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
+		*pcurves = suiteb_curves;
+		*pcurveslen = 2;
+		break;
+
+	case SSL_CERT_FLAG_SUITEB_192_LOS:
+		*pcurves = suiteb_curves + 2;
+		*pcurveslen = 2;
+		break;
+	default:
 		*pcurves = s->tlsext_ellipticcurvelist;
 		*pcurveslen = s->tlsext_ellipticcurvelist_length;
 		}
-	/* If not set use default: for now static structure */
 	if (!*pcurves)
 		{
 		*pcurves = eccurves_default;
 		*pcurveslen = sizeof(eccurves_default);
 		}
 	}
+/* Check a curve is one of our preferences */
+int tls1_check_curve(SSL *s, const unsigned char *p, size_t len)
+	{
+	const unsigned char *curves;
+	size_t curveslen, i;
+	unsigned int suiteb_flags = tls1_suiteb(s);
+	if (len != 3 || p[0] != NAMED_CURVE_TYPE)
+		return 0;
+	/* Check curve matches Suite B preferences */
+	if (suiteb_flags)
+		{
+		unsigned long cid = s->s3->tmp.new_cipher->id;
+		if (p[1])
+			return 0;
+		if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
+			{
+			if (p[2] != TLSEXT_curve_P_256)
+				return 0;
+			}
+		else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
+			{
+			if (p[2] != TLSEXT_curve_P_384)
+				return 0;
+			}
+		else	/* Should never happen */
+			return 0;
+		}
+	tls1_get_curvelist(s, 0, &curves, &curveslen);
+	for (i = 0; i < curveslen; i += 2, curves += 2)
+		{
+		if (p[1] == curves[0] && p[2] == curves[1])
+			return 1;
+		}
+	return 0;
+	}
 
 /* Return nth shared curve. If nmatch == -1 return number of
- * matches.
+ * matches. For nmatch == -2 return the NID of the curve to use for
+ * an EC tmp key.
  */
 
 int tls1_shared_curve(SSL *s, int nmatch)
@@ -346,6 +404,25 @@ int tls1_shared_curve(SSL *s, int nmatch)
 	/* Can't do anything on client side */
 	if (s->server == 0)
 		return -1;
+	if (nmatch == -2)
+		{
+		if (tls1_suiteb(s))
+			{
+			/* For Suite B ciphersuite determines curve: we 
+			 * already know these are acceptable due to previous
+			 * checks.
+			 */
+			unsigned long cid = s->s3->tmp.new_cipher->id;
+			if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
+				return NID_X9_62_prime256v1; /* P-256 */
+			if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
+				return NID_secp384r1; /* P-384 */
+			/* Should never happen */
+			return NID_undef;
+			}
+		/* If not Suite B just return first preference shared curve */
+		nmatch = 0;
+		}
 	tls1_get_curvelist(s, !!(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE),
 				&supp, &supplen);
 	tls1_get_curvelist(s, !(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE),
@@ -525,6 +602,8 @@ static int tls1_check_ec_key(SSL *s,
 		if (i == plen)
 			return 0;
 		}
+	if (!curve_id)
+		return 1;
 	/* Check curve is consistent with client and server preferences */
 	for (j = 0; j <= 1; j++)
 		{
@@ -536,6 +615,9 @@ static int tls1_check_ec_key(SSL *s,
 			}
 		if (i == plen)
 			return 0;
+		/* For clients can only check sent curve list */
+		if (!s->server)
+			return 1;
 		}
 	return 1;
 	}
@@ -543,7 +625,7 @@ static int tls1_check_ec_key(SSL *s,
 /* Check cert parameters compatible with extensions: currently just checks
  * EC certificates have compatible curves and compression.
  */
-static int tls1_check_cert_param(SSL *s, X509 *x)
+static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
 	{
 	unsigned char comp_id, curve_id[2];
 	EVP_PKEY *pkey;
@@ -561,13 +643,87 @@ static int tls1_check_cert_param(SSL *s, X509 *x)
 	EVP_PKEY_free(pkey);
 	if (!rv)
 		return 0;
-	return tls1_check_ec_key(s, curve_id, &comp_id);
+	/* Can't check curve_id for client certs as we don't have a
+	 * supported curves extension.
+	 */
+	rv = tls1_check_ec_key(s, s->server ? curve_id : NULL, &comp_id);
+	if (!rv)
+		return 0;
+	/* Special case for suite B. We *MUST* sign using SHA256+P-256 or
+	 * SHA384+P-384, adjust digest if necessary.
+	 */
+	if (set_ee_md && tls1_suiteb(s))
+		{
+		int check_md;
+		size_t i;
+		CERT *c = s->cert;
+		if (curve_id[0])
+			return 0;
+		/* Check to see we have necessary signing algorithm */
+		if (curve_id[1] == TLSEXT_curve_P_256)
+			check_md = NID_ecdsa_with_SHA256;
+		else if (curve_id[1] == TLSEXT_curve_P_384)
+			check_md = NID_ecdsa_with_SHA384;
+		else
+			return 0; /* Should never happen */
+		for (i = 0; i < c->shared_sigalgslen; i++)
+			if (check_md == c->shared_sigalgs[i].signandhash_nid)
+				break;
+		if (i == c->shared_sigalgslen)
+			return 0;
+		if (set_ee_md == 2)
+			{
+			if (check_md == NID_ecdsa_with_SHA256)
+				c->pkeys[SSL_PKEY_ECC].digest = EVP_sha256();
+			else
+				c->pkeys[SSL_PKEY_ECC].digest = EVP_sha384();
+			}
+		}
+	return rv;
 	}
 /* Check EC temporary key is compatible with client extensions */
-int tls1_check_ec_tmp_key(SSL *s)
+int tls1_check_ec_tmp_key(SSL *s, unsigned long cid)
 	{
 	unsigned char curve_id[2];
 	EC_KEY *ec = s->cert->ecdh_tmp;
+#ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
+	/* Allow any curve: not just those peer supports */
+	if (s->cert->cert_flags & SSL_CERT_FLAG_BROKEN_PROTCOL)
+		return 1;
+#endif
+	/* If Suite B, AES128 MUST use P-256 and AES256 MUST use P-384,
+	 * no other curves permitted.
+	 */
+	if (tls1_suiteb(s))
+		{
+		/* Curve to check determined by ciphersuite */
+		if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
+			curve_id[1] = TLSEXT_curve_P_256;
+		else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
+			curve_id[1] = TLSEXT_curve_P_384;
+		else
+			return 0;
+		curve_id[0] = 0;
+		/* Check this curve is acceptable */
+		if (!tls1_check_ec_key(s, curve_id, NULL))
+			return 0;
+		/* If auto or setting curve from callback assume OK */
+		if (s->cert->ecdh_tmp_auto || s->cert->ecdh_tmp_cb)
+			return 1;
+		/* Otherwise check curve is acceptable */
+		else 
+			{
+			unsigned char curve_tmp[2];
+			if (!ec)
+				return 0;
+			if (!tls1_set_ec_id(curve_tmp, NULL, ec))
+				return 0;
+			if (!curve_tmp[0] || curve_tmp[1] == curve_id[1])
+				return 1;
+			return 0;
+			}
+			
+		}
 	if (s->cert->ecdh_tmp_auto)
 		{
 		/* Need a shared curve */
@@ -583,8 +739,13 @@ int tls1_check_ec_tmp_key(SSL *s)
 			return 0;
 		}
 	if (!tls1_set_ec_id(curve_id, NULL, ec))
-		return 1;
+		return 0;
+/* Set this to allow use of invalid curves for testing */
+#if 0
+	return 1;
+#else
 	return tls1_check_ec_key(s, curve_id, NULL);
+#endif
 	}
 
 #endif /* OPENSSL_NO_EC */
@@ -635,28 +796,213 @@ static unsigned char tls12_sigalgs[] = {
 #endif
 };
 
-size_t tls12_get_sig_algs(SSL *s, unsigned char *p)
+static unsigned char suiteb_sigalgs[] = {
+	tlsext_sigalg_ecdsa(TLSEXT_hash_sha256)
+	tlsext_sigalg_ecdsa(TLSEXT_hash_sha384)
+};
+
+size_t tls12_get_psigalgs(SSL *s, const unsigned char **psigs)
 	{
-	const unsigned char *sigs;
-	size_t sigslen;
-	sigs = s->cert->conf_sigalgs;
+	/* If Suite B mode use Suite B sigalgs only, ignore any other
+	 * preferences.
+	 */
+	switch (tls1_suiteb(s))
+		{
+	case SSL_CERT_FLAG_SUITEB_128_LOS:
+		*psigs = suiteb_sigalgs;
+		return sizeof(suiteb_sigalgs);
+
+	case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
+		*psigs = suiteb_sigalgs;
+		return 2;
 
-	if (sigs)
-		sigslen = s->cert->conf_sigalgslen;
+	case SSL_CERT_FLAG_SUITEB_192_LOS:
+		*psigs = suiteb_sigalgs + 2;
+		return 2;
+		}
+
+	/* If server use client authentication sigalgs if not NULL */
+	if (s->server && s->cert->client_sigalgs)
+		{
+		*psigs = s->cert->client_sigalgs;
+		return s->cert->client_sigalgslen;
+		}
+	else if (s->cert->conf_sigalgs)
+		{
+		*psigs = s->cert->conf_sigalgs;
+		return s->cert->conf_sigalgslen;
+		}
 	else
 		{
-		sigs = tls12_sigalgs;
-		sigslen = sizeof(tls12_sigalgs);
+		*psigs = tls12_sigalgs;
 #ifdef OPENSSL_FIPS
 		/* If FIPS mode don't include MD5 which is last */
 		if (FIPS_mode())
-			sigslen -= 2;
+			return sizeof(tls12_sigalgs) - 2;
+		else
 #endif
+			return sizeof(tls12_sigalgs);
+		}
+	}
+/* Check signature algorithm is consistent with sent supported signature
+ * algorithms and if so return relevant digest.
+ */
+int tls12_check_peer_sigalg(const EVP_MD **pmd, SSL *s,
+				const unsigned char *sig, EVP_PKEY *pkey)
+	{
+	const unsigned char *sent_sigs;
+	size_t sent_sigslen, i;
+	int sigalg = tls12_get_sigid(pkey);
+	/* Should never happen */
+	if (sigalg == -1)
+		return -1;
+	/* Check key type is consistent with signature */
+	if (sigalg != (int)sig[1])
+		{
+		SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_WRONG_SIGNATURE_TYPE);
+		return 0;
+		}
+	if (pkey->type == EVP_PKEY_EC)
+		{
+		unsigned char curve_id[2], comp_id;
+		/* Check compression and curve matches extensions */
+		if (!tls1_set_ec_id(curve_id, &comp_id, pkey->pkey.ec))
+			return 0;
+		if (!s->server && !tls1_check_ec_key(s, curve_id, &comp_id))
+			{
+			SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_WRONG_CURVE);
+			return 0;
+			}
+		/* If Suite B only P-384+SHA384 or P-256+SHA-256 allowed */
+		if (tls1_suiteb(s))
+			{
+			if (curve_id[0])
+				return 0;
+			if (curve_id[1] == TLSEXT_curve_P_256)
+				{
+				if (sig[0] != TLSEXT_hash_sha256)
+					{
+					SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,
+						SSL_R_ILLEGAL_SUITEB_DIGEST);
+					return 0;
+					}
+				}
+			else if (curve_id[1] == TLSEXT_curve_P_384)
+				{
+				if (sig[0] != TLSEXT_hash_sha384)
+					{
+					SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,
+						SSL_R_ILLEGAL_SUITEB_DIGEST);
+					return 0;
+					}
+				}
+			else
+				return 0;
+			}
 		}
+	else if (tls1_suiteb(s))
+		return 0;
 
-	if (p)
-		memcpy(p, sigs, sigslen);
-	return sigslen;
+	/* Check signature matches a type we sent */
+	sent_sigslen = tls12_get_psigalgs(s, &sent_sigs);
+	for (i = 0; i < sent_sigslen; i+=2, sent_sigs+=2)
+		{
+		if (sig[0] == sent_sigs[0] && sig[1] == sent_sigs[1])
+			break;
+		}
+	/* Allow fallback to SHA1 if not strict mode */
+	if (i == sent_sigslen && (sig[0] != TLSEXT_hash_sha1 || s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT))
+		{
+		SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_WRONG_SIGNATURE_TYPE);
+		return 0;
+		}
+	*pmd = tls12_get_hash(sig[0]);
+	if (*pmd == NULL)
+		{
+		SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_UNKNOWN_DIGEST);
+		return 0;
+		}
+	return 1;
+	}
+/* Get a mask of disabled algorithms: an algorithm is disabled
+ * if it isn't supported or doesn't appear in supported signature
+ * algorithms. Unlike ssl_cipher_get_disabled this applies to a specific
+ * session and not global settings.
+ * 
+ */
+void ssl_set_client_disabled(SSL *s)
+	{
+	CERT *c = s->cert;
+	const unsigned char *sigalgs;
+	size_t i, sigalgslen;
+	int have_rsa = 0, have_dsa = 0, have_ecdsa = 0;
+	c->mask_a = 0;
+	c->mask_k = 0;
+	/* If less than TLS 1.2 don't allow TLS 1.2 only ciphers */
+	if (TLS1_get_version(s) < TLS1_2_VERSION)
+		c->mask_ssl = SSL_TLSV1_2;
+	else
+		c->mask_ssl = 0;
+	/* Now go through all signature algorithms seeing if we support
+	 * any for RSA, DSA, ECDSA. Do this for all versions not just
+	 * TLS 1.2.
+	 */
+	sigalgslen = tls12_get_psigalgs(s, &sigalgs);
+	for (i = 0; i < sigalgslen; i += 2, sigalgs += 2)
+		{
+		switch(sigalgs[1])
+			{
+#ifndef OPENSSL_NO_RSA
+		case TLSEXT_signature_rsa:
+			have_rsa = 1;
+			break;
+#endif
+#ifndef OPENSSL_NO_DSA
+		case TLSEXT_signature_dsa:
+			have_dsa = 1;
+			break;
+#endif
+#ifndef OPENSSL_NO_ECDSA
+		case TLSEXT_signature_ecdsa:
+			have_ecdsa = 1;
+			break;
+#endif
+			}
+		}
+	/* Disable auth and static DH if we don't include any appropriate
+	 * signature algorithms.
+	 */
+	if (!have_rsa)
+		{
+		c->mask_a |= SSL_aRSA;
+		c->mask_k |= SSL_kDHr|SSL_kECDHr;
+		}
+	if (!have_dsa)
+		{
+		c->mask_a |= SSL_aDSS;
+		c->mask_k |= SSL_kDHd;
+		}
+	if (!have_ecdsa)
+		{
+		c->mask_a |= SSL_aECDSA;
+		c->mask_k |= SSL_kECDHe;
+		}
+#ifndef OPENSSL_NO_KRB5
+	if (!kssl_tgt_is_available(s->kssl_ctx))
+		{
+		c->mask_a |= SSL_aKRB5;
+		c->mask_k |= SSL_kKRB5;
+		}
+#endif
+#ifndef OPENSSL_NO_PSK
+	/* with PSK there must be client callback set */
+	if (!s->psk_client_callback)
+		{
+		c->mask_a |= SSL_aPSK;
+		c->mask_k |= SSL_kPSK;
+		}
+#endif /* OPENSSL_NO_PSK */
+	c->valid = 1;
 	}
 
 /* byte_compare is a compare function for qsort(3) that compares bytes. */
@@ -892,13 +1238,14 @@ unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned cha
 	if (TLS1_get_client_version(s) >= TLS1_2_VERSION)
 		{
 		size_t salglen;
-		salglen = tls12_get_sig_algs(s, NULL);
+		const unsigned char *salg;
+		salglen = tls12_get_psigalgs(s, &salg);
 		if ((size_t)(limit - ret) < salglen + 6)
 			return NULL; 
 		s2n(TLSEXT_TYPE_signature_algorithms,ret);
 		s2n(salglen + 2, ret);
 		s2n(salglen, ret);
-		tls12_get_sig_algs(s, ret);
+		memcpy(ret, salg, salglen);
 		ret += salglen;
 		}
 
@@ -1309,6 +1656,7 @@ static int ssl_scan_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char
 	unsigned short len;
 	unsigned char *data = *p;
 	int renegotiate_seen = 0;
+	size_t i;
 
 	s->servername_done = 0;
 	s->tlsext_status_type = -1;
@@ -1332,6 +1680,12 @@ static int ssl_scan_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char
 		OPENSSL_free(s->cert->shared_sigalgs);
 		s->cert->shared_sigalgs = NULL;
 		}
+	/* Clear certificate digests and validity flags */
+	for (i = 0; i < SSL_PKEY_NUM; i++)
+		{
+		s->cert->pkeys[i].digest = NULL;
+		s->cert->pkeys[i].valid_flags = 0;
+		}
 
 	if (data >= (d+n-2))
 		goto ri_check;
@@ -1819,7 +2173,6 @@ static int ssl_scan_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char
 			 * in the case of a session resumption. */
 			if (!s->hit)
 				{
-				size_t i;
 				if (s->s3->tlsext_authz_client_types != NULL)
 					OPENSSL_free(s->s3->tlsext_authz_client_types);
 				s->s3->tlsext_authz_client_types =
@@ -2905,7 +3258,7 @@ static int tls12_get_pkey_idx(unsigned char sig_alg)
 static void tls1_lookup_sigalg(int *phash_nid, int *psign_nid,
 			int *psignhash_nid, const unsigned char *data)
 	{
-	int sign_nid, hash_nid;
+	int sign_nid = 0, hash_nid = 0;
 	if (!phash_nid && !psign_nid && !psignhash_nid)
 		return;
 	if (phash_nid || psignhash_nid)
@@ -2975,19 +3328,21 @@ static int tls1_set_shared_sigalgs(SSL *s)
 	size_t nmatch;
 	TLS_SIGALGS *salgs = NULL;
 	CERT *c = s->cert;
-	conf = c->conf_sigalgs;
-	if (conf)
-		conflen = c->conf_sigalgslen;
-	else
+	unsigned int is_suiteb = tls1_suiteb(s);
+	/* If client use client signature algorithms if not NULL */
+	if (!s->server && c->client_sigalgs && !is_suiteb)
 		{
-		conf = tls12_sigalgs;
-		conflen = sizeof(tls12_sigalgs);
-#ifdef OPENSSL_FIPS
-		if (FIPS_mode())
-			conflen -= 2;
-#endif
+		conf = c->client_sigalgs;
+		conflen = c->client_sigalgslen;
 		}
-	if(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE)
+	else if (c->conf_sigalgs && !is_suiteb)
+		{
+		conf = c->conf_sigalgs;
+		conflen = c->conf_sigalgslen;
+		}
+	else
+		conflen = tls12_get_psigalgs(s, &conf);
+	if(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE || is_suiteb)
 		{
 		pref = conf;
 		preflen = conflen;
@@ -3030,11 +3385,6 @@ int tls1_process_sigalgs(SSL *s, const unsigned char *data, int dsize)
 	if (!c)
 		return 0;
 
-	c->pkeys[SSL_PKEY_DSA_SIGN].digest = NULL;
-	c->pkeys[SSL_PKEY_RSA_SIGN].digest = NULL;
-	c->pkeys[SSL_PKEY_RSA_ENC].digest = NULL;
-	c->pkeys[SSL_PKEY_ECC].digest = NULL;
-
 	c->peer_sigalgs = OPENSSL_malloc(dsize);
 	if (!c->peer_sigalgs)
 		return 0;
@@ -3043,6 +3393,32 @@ int tls1_process_sigalgs(SSL *s, const unsigned char *data, int dsize)
 
 	tls1_set_shared_sigalgs(s);
 
+#ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
+	if (s->cert->cert_flags & SSL_CERT_FLAG_BROKEN_PROTCOL)
+		{
+		/* Use first set signature preference to force message
+		 * digest, ignoring any peer preferences.
+		 */
+		const unsigned char *sigs = NULL;
+		if (s->server)
+			sigs = c->conf_sigalgs;
+		else
+			sigs = c->client_sigalgs;
+		if (sigs)
+			{
+			idx = tls12_get_pkey_idx(sigs[1]);
+			md = tls12_get_hash(sigs[0]);
+			c->pkeys[idx].digest = md;
+			c->pkeys[idx].valid_flags = CERT_PKEY_EXPLICIT_SIGN;
+			if (idx == SSL_PKEY_RSA_SIGN)
+				{
+				c->pkeys[SSL_PKEY_RSA_ENC].valid_flags = CERT_PKEY_EXPLICIT_SIGN;
+				c->pkeys[SSL_PKEY_RSA_ENC].digest = md;
+				}
+			}
+		}
+#endif
+
 	for (i = 0, sigptr = c->shared_sigalgs;
 			i < c->shared_sigalgslen; i++, sigptr++)
 		{
@@ -3051,15 +3427,19 @@ int tls1_process_sigalgs(SSL *s, const unsigned char *data, int dsize)
 			{
 			md = tls12_get_hash(sigptr->rhash);
 			c->pkeys[idx].digest = md;
+			c->pkeys[idx].valid_flags = CERT_PKEY_EXPLICIT_SIGN;
 			if (idx == SSL_PKEY_RSA_SIGN)
+				{
+				c->pkeys[SSL_PKEY_RSA_ENC].valid_flags = CERT_PKEY_EXPLICIT_SIGN;
 				c->pkeys[SSL_PKEY_RSA_ENC].digest = md;
+				}
 			}
 
 		}
 	/* In strict mode leave unset digests as NULL to indicate we can't
 	 * use the certificate for signing.
 	 */
-	if (!(s->cert->cert_flags & SSL_CERT_FLAG_TLS_STRICT))
+	if (!(s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT))
 		{
 		/* Set any remaining keys to default values. NOTE: if alg is
 		 * not supported it stays as NULL.
@@ -3328,16 +3708,16 @@ static int sig_cb(const char *elem, int len, void *arg)
 
 /* Set suppored signature algorithms based on a colon separated list
  * of the form sig+hash e.g. RSA+SHA512:DSA+SHA512 */
-int tls1_set_sigalgs_list(CERT *c, const char *str)
+int tls1_set_sigalgs_list(CERT *c, const char *str, int client)
 	{
 	sig_cb_st sig;
 	sig.sigalgcnt = 0;
 	if (!CONF_parse_list(str, ':', 1, sig_cb, &sig))
 		return 0;
-	return tls1_set_sigalgs(c, sig.sigalgs, sig.sigalgcnt);
+	return tls1_set_sigalgs(c, sig.sigalgs, sig.sigalgcnt, client);
 	}
 
-int tls1_set_sigalgs(CERT *c, const int *psig_nids, size_t salglen)
+int tls1_set_sigalgs(CERT *c, const int *psig_nids, size_t salglen, int client)
 	{
 	unsigned char *sigalgs, *sptr;
 	int rhash, rsign;
@@ -3360,11 +3740,21 @@ int tls1_set_sigalgs(CERT *c, const int *psig_nids, size_t salglen)
 		*sptr++ = rsign;
 		}
 
-	if (c->conf_sigalgs)
-		OPENSSL_free(c->conf_sigalgs);
+	if (client)
+		{
+		if (c->client_sigalgs)
+			OPENSSL_free(c->client_sigalgs);
+		c->client_sigalgs = sigalgs;
+		c->client_sigalgslen = salglen;
+		}
+	else
+		{
+		if (c->conf_sigalgs)
+			OPENSSL_free(c->conf_sigalgs);
+		c->conf_sigalgs = sigalgs;
+		c->conf_sigalgslen = salglen;
+		}
 
-	c->conf_sigalgs = sigalgs;
-	c->conf_sigalgslen = salglen;
 	return 1;
 
 	err:
@@ -3386,40 +3776,107 @@ static int tls1_check_sig_alg(CERT *c, X509 *x, int default_nid)
 			return 1;
 	return 0;
 	}
+/* Check to see if a certificate issuer name matches list of CA names */
+static int ssl_check_ca_name(STACK_OF(X509_NAME) *names, X509 *x)
+	{
+	X509_NAME *nm;
+	int i;
+	nm = X509_get_issuer_name(x);
+	for (i = 0; i < sk_X509_NAME_num(names); i++)
+		{
+		if(!X509_NAME_cmp(nm, sk_X509_NAME_value(names, i)))
+			return 1;
+		}
+	return 0;
+	}
 
 /* Check certificate chain is consistent with TLS extensions and is
- * usable by server.
+ * usable by server. This servers two purposes: it allows users to 
+ * check chains before passing them to the server and it allows the
+ * server to check chains before attempting to use them.
  */
+
+/* Flags which need to be set for a certificate when stict mode not set */
+
+#define CERT_PKEY_VALID_FLAGS \
+	(CERT_PKEY_EE_SIGNATURE|CERT_PKEY_EE_PARAM)
+/* Strict mode flags */
+#define CERT_PKEY_STRICT_FLAGS \
+	 (CERT_PKEY_VALID_FLAGS|CERT_PKEY_CA_SIGNATURE|CERT_PKEY_CA_PARAM \
+	 | CERT_PKEY_ISSUER_NAME|CERT_PKEY_CERT_TYPE)
+
 int tls1_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain,
 									int idx)
 	{
 	int i;
-	int rv = CERT_PKEY_INVALID;
+	int rv = 0;
+	int check_flags = 0, strict_mode;
 	CERT_PKEY *cpk = NULL;
 	CERT *c = s->cert;
+	unsigned int suiteb_flags = tls1_suiteb(s);
+	/* idx == -1 means checking server chains */
 	if (idx != -1)
 		{
-		cpk = c->pkeys + idx;
+		/* idx == -2 means checking client certificate chains */
+		if (idx == -2)
+			{
+			cpk = c->key;
+			idx = cpk - c->pkeys;
+			}
+		else
+			cpk = c->pkeys + idx;
 		x = cpk->x509;
 		pk = cpk->privatekey;
 		chain = cpk->chain;
+		strict_mode = c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT;
 		/* If no cert or key, forget it */
 		if (!x || !pk)
 			goto end;
+#ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
+		/* Allow any certificate to pass test */
+		if (s->cert->cert_flags & SSL_CERT_FLAG_BROKEN_PROTCOL)
+			{
+			rv = CERT_PKEY_STRICT_FLAGS|CERT_PKEY_EXPLICIT_SIGN|CERT_PKEY_VALID|CERT_PKEY_SIGN;
+			cpk->valid_flags = rv;
+			return rv;
+			}
+#endif
 		}
 	else
 		{
+		if (!x || !pk)
+			goto end;
 		idx = ssl_cert_type(x, pk);
 		if (idx == -1)
 			goto end;
+		cpk = c->pkeys + idx;
+		if (c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)
+			check_flags = CERT_PKEY_STRICT_FLAGS;
+		else
+			check_flags = CERT_PKEY_VALID_FLAGS;
+		strict_mode = 1;
+		}
+
+	if (suiteb_flags)
+		{
+		int ok;
+		if (check_flags)
+			check_flags |= CERT_PKEY_SUITEB;
+		ok = X509_chain_check_suiteb(NULL, x, chain, suiteb_flags);
+		if (ok != X509_V_OK)
+			{
+			if (check_flags)
+				rv |= CERT_PKEY_SUITEB;
+			else
+				goto end;
+			}
 		}
 
 	/* Check all signature algorithms are consistent with
 	 * signature algorithms extension if TLS 1.2 or later
 	 * and strict mode.
 	 */
-	if (TLS1_get_version(s) >= TLS1_2_VERSION
-		&& c->cert_flags & SSL_CERT_FLAG_TLS_STRICT)
+	if (TLS1_get_version(s) >= TLS1_2_VERSION && strict_mode)
 		{
 		int default_nid;
 		unsigned char rsign = 0;
@@ -3467,39 +3924,176 @@ int tls1_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain,
 					break;
 				}
 			if (j == c->conf_sigalgslen)
-				goto end;
+				{
+				if (check_flags)
+					goto skip_sigs;
+				else
+					goto end;
+				}
 			}
 		/* Check signature algorithm of each cert in chain */
 		if (!tls1_check_sig_alg(c, x, default_nid))
-			goto end;
+			{
+			if (!check_flags) goto end;
+			}
+		else
+			rv |= CERT_PKEY_EE_SIGNATURE;
+		rv |= CERT_PKEY_CA_SIGNATURE;
 		for (i = 0; i < sk_X509_num(chain); i++)
 			{
 			if (!tls1_check_sig_alg(c, sk_X509_value(chain, i),
 							default_nid))
-				goto end;
+				{
+				if (check_flags)
+					{
+					rv &= ~CERT_PKEY_CA_SIGNATURE;
+					break;
+					}
+				else
+					goto end;
+				}
 			}
 		}
-
+	/* Else not TLS 1.2, so mark EE and CA signing algorithms OK */
+	else if(check_flags)
+		rv |= CERT_PKEY_EE_SIGNATURE|CERT_PKEY_CA_SIGNATURE;
+	skip_sigs:
 	/* Check cert parameters are consistent */
-	if (!tls1_check_cert_param(s, x))
+	if (tls1_check_cert_param(s, x, check_flags ? 1 : 2))
+		rv |= CERT_PKEY_EE_PARAM;
+	else if (!check_flags)
 		goto end;
+	if (!s->server)
+		rv |= CERT_PKEY_CA_PARAM;
 	/* In strict mode check rest of chain too */
-	if (c->cert_flags & SSL_CERT_FLAG_TLS_STRICT)
+	else if (strict_mode)
 		{
+		rv |= CERT_PKEY_CA_PARAM;
 		for (i = 0; i < sk_X509_num(chain); i++)
 			{
-			if (!tls1_check_cert_param(s, sk_X509_value(chain, i)))
+			X509 *ca = sk_X509_value(chain, i);
+			if (!tls1_check_cert_param(s, ca, 0))
+				{
+				if (check_flags)
+					{
+					rv &= ~CERT_PKEY_CA_PARAM;
+					break;
+					}
+				else
+					goto end;
+				}
+			}
+		}
+	if (!s->server && strict_mode)
+		{
+		STACK_OF(X509_NAME) *ca_dn;
+		int check_type = 0;
+		switch (pk->type)
+			{
+		case EVP_PKEY_RSA:
+			check_type = TLS_CT_RSA_SIGN;
+			break;
+		case EVP_PKEY_DSA:
+			check_type = TLS_CT_DSS_SIGN;
+			break;
+		case EVP_PKEY_EC:
+			check_type = TLS_CT_ECDSA_SIGN;
+			break;
+		case EVP_PKEY_DH:
+		case EVP_PKEY_DHX:
+				{
+				int cert_type = X509_certificate_type(x, pk);
+				if (cert_type & EVP_PKS_RSA)
+					check_type = TLS_CT_RSA_FIXED_DH;
+				if (cert_type & EVP_PKS_DSA)
+					check_type = TLS_CT_DSS_FIXED_DH;
+				}
+			}
+		if (check_type)
+			{
+			const unsigned char *ctypes;
+			int ctypelen;
+			if (c->ctypes)
+				{
+				ctypes = c->ctypes;
+				ctypelen = (int)c->ctype_num;
+				}
+			else
+				{
+				ctypes = (unsigned char *)s->s3->tmp.ctype;
+				ctypelen = s->s3->tmp.ctype_num;
+				}
+			for (i = 0; i < ctypelen; i++)
+				{
+				if (ctypes[i] == check_type)
+					{
+					rv |= CERT_PKEY_CERT_TYPE;
+					break;
+					}
+				}
+			if (!(rv & CERT_PKEY_CERT_TYPE) && !check_flags)
 				goto end;
 			}
+		else
+			rv |= CERT_PKEY_CERT_TYPE;
+
+
+		ca_dn = s->s3->tmp.ca_names;
+
+		if (!sk_X509_NAME_num(ca_dn))
+			rv |= CERT_PKEY_ISSUER_NAME;
+
+		if (!(rv & CERT_PKEY_ISSUER_NAME))
+			{
+			if (ssl_check_ca_name(ca_dn, x))
+				rv |= CERT_PKEY_ISSUER_NAME;
+			}
+		if (!(rv & CERT_PKEY_ISSUER_NAME))
+			{
+			for (i = 0; i < sk_X509_num(chain); i++)
+				{
+				X509 *xtmp = sk_X509_value(chain, i);
+				if (ssl_check_ca_name(ca_dn, xtmp))
+					{
+					rv |= CERT_PKEY_ISSUER_NAME;
+					break;
+					}
+				}
+			}
+		if (!check_flags && !(rv & CERT_PKEY_ISSUER_NAME))
+			goto end;
 		}
-	rv = CERT_PKEY_VALID;
+	else
+		rv |= CERT_PKEY_ISSUER_NAME|CERT_PKEY_CERT_TYPE;
+
+	if (!check_flags || (rv & check_flags) == check_flags)
+		rv |= CERT_PKEY_VALID;
 
 	end:
-	if (cpk)
+
+	if (TLS1_get_version(s) >= TLS1_2_VERSION)
 		{
-		if (rv && cpk->digest)
+		if (cpk->valid_flags & CERT_PKEY_EXPLICIT_SIGN)
+			rv |= CERT_PKEY_EXPLICIT_SIGN|CERT_PKEY_SIGN;
+		else if (cpk->digest)
 			rv |= CERT_PKEY_SIGN;
-		cpk->valid_flags = rv;
+		}
+	else
+		rv |= CERT_PKEY_SIGN|CERT_PKEY_EXPLICIT_SIGN;
+
+	/* When checking a CERT_PKEY structure all flags are irrelevant
+	 * if the chain is invalid.
+	 */
+	if (!check_flags)
+		{
+		if (rv & CERT_PKEY_VALID)
+			cpk->valid_flags = rv;
+		else
+			{
+			/* Preserve explicit sign flag, clear rest */
+			cpk->valid_flags &= CERT_PKEY_EXPLICIT_SIGN;
+			return 0;
+			}
 		}
 	return rv;
 	}
@@ -3514,5 +4108,10 @@ void tls1_set_cert_validity(SSL *s)
 	tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_DH_DSA);
 	tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_ECC);
 	}
+/* User level utiity function to check a chain is suitable */
+int SSL_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain)
+	{
+	return tls1_check_chain(s, x, pk, chain, -1);
+	}
 
 #endif