Added strongswan.conf options to filter cipher suites by specific algorithms

src/libtls/tls_crypto.c

@@ -686,6 +686,174 @@ static void filter_key_suites(private_tls_crypto_t *this,
 	*count = remaining;
 }
 
+/**
+ * Filter suites by key exchange user config
+ */
+static void filter_key_exchange_config_suites(private_tls_crypto_t *this,
+											  suite_algs_t suites[], int *count)
+{
+	enumerator_t *enumerator;
+	int i, remaining = 0;
+	char *token, *config;
+
+	config = lib->settings->get_str(lib->settings, "libtls.key_exchange", NULL);
+	if (config)
+	{
+		for (i = 0; i < *count; i++)
+		{
+			enumerator = enumerator_create_token(config, ",", " ");
+			while (enumerator->enumerate(enumerator, &token))
+			{
+				if (strcaseeq(token, "ecdhe-ecdsa") &&
+					diffie_hellman_group_is_ec(suites[i].dh) &&
+					suites[i].key == KEY_ECDSA)
+				{
+					suites[remaining++] = suites[i];
+					break;
+				}
+				if (strcaseeq(token, "ecdhe-rsa") &&
+					diffie_hellman_group_is_ec(suites[i].dh) &&
+					suites[i].key == KEY_RSA)
+				{
+					suites[remaining++] = suites[i];
+					break;
+				}
+				if (strcaseeq(token, "dhe-rsa") &&
+					!diffie_hellman_group_is_ec(suites[i].dh) &&
+					suites[i].dh != MODP_NONE &&
+					suites[i].key == KEY_RSA)
+				{
+					suites[remaining++] = suites[i];
+					break;
+				}
+				if (strcaseeq(token, "rsa") &&
+					suites[i].dh == MODP_NONE &&
+					suites[i].key == KEY_RSA)
+				{
+					suites[remaining++] = suites[i];
+					break;
+				}
+			}
+			enumerator->destroy(enumerator);
+		}
+		*count = remaining;
+	}
+}
+
+/**
+ * Filter suites by cipher user config
+ */
+static void filter_cipher_config_suites(private_tls_crypto_t *this,
+										suite_algs_t suites[], int *count)
+{
+	enumerator_t *enumerator;
+	int i, remaining = 0;
+	char *token, *config;
+
+	config = lib->settings->get_str(lib->settings, "libtls.cipher", NULL);
+	if (config)
+	{
+		for (i = 0; i < *count; i++)
+		{
+			enumerator = enumerator_create_token(config, ",", " ");
+			while (enumerator->enumerate(enumerator, &token))
+			{
+				if (strcaseeq(token, "aes128") &&
+					suites[i].encr == ENCR_AES_CBC &&
+					suites[i].encr_size == 16)
+				{
+					suites[remaining++] = suites[i];
+					break;
+				}
+				if (strcaseeq(token, "aes256") &&
+					suites[i].encr == ENCR_AES_CBC &&
+					suites[i].encr_size == 32)
+				{
+					suites[remaining++] = suites[i];
+					break;
+				}
+				if (strcaseeq(token, "camellia128") &&
+					suites[i].encr == ENCR_CAMELLIA_CBC &&
+					suites[i].encr_size == 16)
+				{
+					suites[remaining++] = suites[i];
+					break;
+				}
+				if (strcaseeq(token, "camellia256") &&
+					suites[i].encr == ENCR_CAMELLIA_CBC &&
+					suites[i].encr_size == 32)
+				{
+					suites[remaining++] = suites[i];
+					break;
+				}
+				if (strcaseeq(token, "3des") &&
+					suites[i].encr == ENCR_3DES)
+				{
+					suites[remaining++] = suites[i];
+					break;
+				}
+				if (strcaseeq(token, "null") &&
+					suites[i].encr == ENCR_NULL)
+				{
+					suites[remaining++] = suites[i];
+					break;
+				}
+			}
+			enumerator->destroy(enumerator);
+		}
+		*count = remaining;
+	}
+}
+
+/**
+ * Filter suites by mac user config
+ */
+static void filter_mac_config_suites(private_tls_crypto_t *this,
+									 suite_algs_t suites[], int *count)
+{
+	enumerator_t *enumerator;
+	int i, remaining = 0;
+	char *token, *config;
+
+	config = lib->settings->get_str(lib->settings, "libtls.mac", NULL);
+	if (config)
+	{
+		for (i = 0; i < *count; i++)
+		{
+			enumerator = enumerator_create_token(config, ",", " ");
+			while (enumerator->enumerate(enumerator, &token))
+			{
+				if (strcaseeq(token, "md5") &&
+					suites[i].hash == HASH_MD5)
+				{
+					suites[remaining++] = suites[i];
+					break;
+				}
+				if (strcaseeq(token, "sha1") &&
+					suites[i].hash == HASH_SHA1)
+				{
+					suites[remaining++] = suites[i];
+					break;
+				}
+				if (strcaseeq(token, "sha256") &&
+					suites[i].hash == HASH_SHA256)
+				{
+					suites[remaining++] = suites[i];
+					break;
+				}
+				if (strcaseeq(token, "sha384") &&
+					suites[i].hash == HASH_SHA384)
+				{
+					suites[remaining++] = suites[i];
+					break;
+				}
+			}
+			enumerator->destroy(enumerator);
+		}
+		*count = remaining;
+	}
+}
+
 /**
  * Initialize the cipher suite list
  */
@@ -725,6 +893,11 @@ static void build_cipher_suite_list(private_tls_crypto_t *this,
 	filter_suite(this, suites, &count, offsetof(suite_algs_t, dh),
 				 lib->crypto->create_dh_enumerator);
 
+	/* filter suites with strongswan.conf options */
+	filter_key_exchange_config_suites(this, suites, &count);
+	filter_cipher_config_suites(this, suites, &count);
+	filter_mac_config_suites(this, suites, &count);
+
 	free(this->suites);
 	this->suite_count = count;
 	this->suites = malloc(sizeof(tls_cipher_suite_t) * count);