verify that the algorithm of the received certificate matches the expected.

3 files changed, 56 insertions, 15 deletions

diff --git a/lib/algorithms.h b/lib/algorithms.h
index 394a81fbbd..ae7bbae619 100644
--- a/lib/algorithms.h
+++ b/lib/algorithms.h
@@ -257,6 +257,7 @@ inline static int _gnutls_cipher_get_tag_size(const cipher_entry_st * e)
 
 /* Functions for key exchange. */
 int _gnutls_kx_needs_dh_params(gnutls_kx_algorithm_t algorithm);
+int _gnutls_kx_cert_pk_params(gnutls_kx_algorithm_t algorithm);
 int _gnutls_kx_needs_rsa_params(gnutls_kx_algorithm_t algorithm);
 mod_auth_st *_gnutls_kx_auth_struct(gnutls_kx_algorithm_t algorithm);
 int _gnutls_kx_is_ok(gnutls_kx_algorithm_t algorithm);
diff --git a/lib/algorithms/kx.c b/lib/algorithms/kx.c
index 3fa8a317e0..7302da2967 100644
--- a/lib/algorithms/kx.c
+++ b/lib/algorithms/kx.c
@@ -87,40 +87,41 @@ struct gnutls_kx_algo_entry {
 	gnutls_kx_algorithm_t algorithm;
 	mod_auth_st *auth_struct;
 	int needs_dh_params;
+	gnutls_pk_algorithm_t cert_pk; /* the type of certificate required */
 };
 typedef struct gnutls_kx_algo_entry gnutls_kx_algo_entry;
 
 static const gnutls_kx_algo_entry _gnutls_kx_algorithms[] = {
 #if defined(ENABLE_ANON) && defined(ENABLE_DHE)
-	{"ANON-DH", GNUTLS_KX_ANON_DH, &anon_auth_struct, 1},
+	{"ANON-DH", GNUTLS_KX_ANON_DH, &anon_auth_struct, 1, GNUTLS_PK_UNKNOWN},
 #endif
 #if defined(ENABLE_ANON) && defined(ENABLE_ECDHE)
-	{"ANON-ECDH", GNUTLS_KX_ANON_ECDH, &anon_ecdh_auth_struct, 0},
+	{"ANON-ECDH", GNUTLS_KX_ANON_ECDH, &anon_ecdh_auth_struct, 0, GNUTLS_PK_UNKNOWN},
 #endif
-	{"RSA", GNUTLS_KX_RSA, &rsa_auth_struct},
+	{"RSA", GNUTLS_KX_RSA, &rsa_auth_struct, GNUTLS_PK_RSA},
 #ifdef ENABLE_DHE
-	{"DHE-RSA", GNUTLS_KX_DHE_RSA, &dhe_rsa_auth_struct, 1},
-	{"DHE-DSS", GNUTLS_KX_DHE_DSS, &dhe_dss_auth_struct, 1},
+	{"DHE-RSA", GNUTLS_KX_DHE_RSA, &dhe_rsa_auth_struct, 1, GNUTLS_PK_RSA},
+	{"DHE-DSS", GNUTLS_KX_DHE_DSS, &dhe_dss_auth_struct, 1, GNUTLS_PK_DSA},
 #endif
 #ifdef ENABLE_ECDHE
-	{"ECDHE-RSA", GNUTLS_KX_ECDHE_RSA, &ecdhe_rsa_auth_struct, 0},
+	{"ECDHE-RSA", GNUTLS_KX_ECDHE_RSA, &ecdhe_rsa_auth_struct, 0, GNUTLS_PK_RSA},
 	{"ECDHE-ECDSA", GNUTLS_KX_ECDHE_ECDSA, &ecdhe_ecdsa_auth_struct,
-	 0},
+	 0, GNUTLS_PK_EC},
 #endif
 #ifdef ENABLE_SRP
-	{"SRP-DSS", GNUTLS_KX_SRP_DSS, &srp_dss_auth_struct, 0},
-	{"SRP-RSA", GNUTLS_KX_SRP_RSA, &srp_rsa_auth_struct, 0},
-	{"SRP", GNUTLS_KX_SRP, &srp_auth_struct, 0},
+	{"SRP-DSS", GNUTLS_KX_SRP_DSS, &srp_dss_auth_struct, 0, GNUTLS_PK_DSA},
+	{"SRP-RSA", GNUTLS_KX_SRP_RSA, &srp_rsa_auth_struct, 0, GNUTLS_PK_RSA},
+	{"SRP", GNUTLS_KX_SRP, &srp_auth_struct, 0, GNUTLS_PK_UNKNOWN},
 #endif
 #ifdef ENABLE_PSK
-	{"PSK", GNUTLS_KX_PSK, &psk_auth_struct, 0},
-	{"RSA-PSK", GNUTLS_KX_RSA_PSK, &rsa_psk_auth_struct, 0},
+	{"PSK", GNUTLS_KX_PSK, &psk_auth_struct, 0, GNUTLS_PK_UNKNOWN},
+	{"RSA-PSK", GNUTLS_KX_RSA_PSK, &rsa_psk_auth_struct, 0, GNUTLS_PK_RSA},
 #ifdef ENABLE_DHE
 	{"DHE-PSK", GNUTLS_KX_DHE_PSK, &dhe_psk_auth_struct,
-	 1 /* needs DHE params */ },
+	 1 /* needs DHE params */, GNUTLS_PK_UNKNOWN},
 #endif
 #ifdef ENABLE_ECDHE
-	{"ECDHE-PSK", GNUTLS_KX_ECDHE_PSK, &ecdhe_psk_auth_struct, 0},
+	{"ECDHE-PSK", GNUTLS_KX_ECDHE_PSK, &ecdhe_psk_auth_struct, 0, GNUTLS_PK_UNKNOWN},
 #endif
 #endif
 	{0, 0, 0, 0}
@@ -241,6 +242,13 @@ int _gnutls_kx_needs_dh_params(gnutls_kx_algorithm_t algorithm)
 	return ret;
 }
 
+int _gnutls_kx_cert_pk_params(gnutls_kx_algorithm_t algorithm)
+{
+	ssize_t ret = 0;
+	GNUTLS_KX_ALG_LOOP(ret = p->cert_pk);
+	return ret;
+}
+
 /* Type to KX mappings */
 gnutls_kx_algorithm_t
 _gnutls_map_kx_get_kx(gnutls_credentials_type_t type, int server)
diff --git a/lib/auth/cert.c b/lib/auth/cert.c
index 6e86091b71..4490a075cd 100644
--- a/lib/auth/cert.c
+++ b/lib/auth/cert.c
@@ -1024,9 +1024,36 @@ _gnutls_gen_cert_server_crt(gnutls_session_t session,
 	}
 }
 
+static
+int check_pk_compat(gnutls_session_t session, gnutls_pubkey_t pubkey)
+{
+	unsigned cert_pk;
+	unsigned req_cert_pk;
+	unsigned kx;
+
+	cert_pk = gnutls_pubkey_get_pk_algorithm(pubkey, NULL);
+	if (cert_pk == GNUTLS_PK_UNKNOWN) {
+		gnutls_assert();
+		return GNUTLS_E_CERTIFICATE_ERROR;
+	}
+
+	kx = _gnutls_cipher_suite_get_kx_algo(session->security_parameters.cipher_suite);
+
+	req_cert_pk = _gnutls_kx_cert_pk_params(kx);
+
+	if (req_cert_pk == GNUTLS_PK_UNKNOWN) /* doesn't matter */
+		return 0;
+
+	if (req_cert_pk != cert_pk) {
+		gnutls_assert();
+		return GNUTLS_E_CERTIFICATE_ERROR;
+	}
+
+	return 0;
+}
+
 /* Process server certificate
  */
-
 #define CLEAR_CERTS for(x=0;x<peer_certificate_list_size;x++) gnutls_pcert_deinit(&peer_certificate_list[x])
 static int
 _gnutls_proc_x509_server_crt(gnutls_session_t session,
@@ -1134,6 +1161,11 @@ _gnutls_proc_x509_server_crt(gnutls_session_t session,
 		p += len;
 	}
 
+	ret = check_pk_compat(session, peer_certificate_list[0].pubkey);
+	if (ret < 0) {
+		gnutls_assert();
+		goto cleanup;
+	}
 
 	if ((ret =
 	     _gnutls_copy_certificate_auth_info(info,