Support building with BoringSSL

BoringSSL is Google's cleanup of OpenSSL and an attempt to unify
Chromium, Android and internal codebases around a single OpenSSL.

As part of moving Android to BoringSSL, the wpa_supplicant maintainers
in Android requested that I upstream the change. I've worked to reduce
the size of the patch a lot but I'm afraid that it still contains a
number of #ifdefs.

[1] https://www.imperialviolet.org/2014/06/20/boringssl.html

Signed-off-by: Adam Langley <agl@chromium.org>

src/crypto/crypto_openssl.c

@@ -40,7 +40,7 @@
 
 static BIGNUM * get_group5_prime(void)
 {
-#if OPENSSL_VERSION_NUMBER < 0x00908000
+#if OPENSSL_VERSION_NUMBER < 0x00908000 || defined(OPENSSL_IS_BORINGSSL)
 	static const unsigned char RFC3526_PRIME_1536[] = {
 		0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xC9,0x0F,0xDA,0xA2,
 		0x21,0x68,0xC2,0x34,0xC4,0xC6,0x62,0x8B,0x80,0xDC,0x1C,0xD1,
@@ -130,7 +130,7 @@ void des_encrypt(const u8 *clear, const u8 *key, u8 *cypher)
 	}
 	pkey[i] = next | 1;
 
-	DES_set_key(&pkey, &ks);
+	DES_set_key((DES_cblock *) &pkey, &ks);
 	DES_ecb_encrypt((DES_cblock *) clear, (DES_cblock *) cypher, &ks,
 			DES_ENCRYPT);
 }
@@ -199,8 +199,10 @@ static const EVP_CIPHER * aes_get_evp_cipher(size_t keylen)
 	switch (keylen) {
 	case 16:
 		return EVP_aes_128_ecb();
+#ifndef OPENSSL_IS_BORINGSSL
 	case 24:
 		return EVP_aes_192_ecb();
+#endif /* OPENSSL_IS_BORINGSSL */
 	case 32:
 		return EVP_aes_256_ecb();
 	}
@@ -378,9 +380,11 @@ struct crypto_cipher * crypto_cipher_init(enum crypto_cipher_alg alg,
 		case 16:
 			cipher = EVP_aes_128_cbc();
 			break;
+#ifndef OPENSSL_IS_BORINGSSL
 		case 24:
 			cipher = EVP_aes_192_cbc();
 			break;
+#endif /* OPENSSL_IS_BORINGSSL */
 		case 32:
 			cipher = EVP_aes_256_cbc();
 			break;

src/crypto/tls_openssl.c

@@ -38,14 +38,26 @@
 #define OPENSSL_SUPPORTS_CTX_APP_DATA
 #endif
 
-#ifdef SSL_F_SSL_SET_SESSION_TICKET_EXT
+#if OPENSSL_VERSION_NUMBER < 0x10000000L
-#ifdef SSL_OP_NO_TICKET
+/* ERR_remove_thread_state replaces ERR_remove_state and the latter is
+ * deprecated. However, OpenSSL 0.9.8 doesn't include
+ * ERR_remove_thread_state. */
+#define ERR_remove_thread_state(tid) ERR_remove_state(0)
+#endif
+
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
 /*
  * Session ticket override patch was merged into OpenSSL 0.9.9 tree on
  * 2008-11-15. This version uses a bit different API compared to the old patch.
  */
 #define CONFIG_OPENSSL_TICKET_OVERRIDE
 #endif
+
+#if defined(OPENSSL_IS_BORINGSSL)
+/* stack_index_t is the return type of OpenSSL's sk_XXX_num() functions. */
+typedef size_t stack_index_t;
+#else
+typedef int stack_index_t;
 #endif
 
 #ifdef SSL_set_tlsext_status_type
@@ -853,7 +865,7 @@ void tls_deinit(void *ssl_ctx)
 		ENGINE_cleanup();
 #endif /* OPENSSL_NO_ENGINE */
 		CRYPTO_cleanup_all_ex_data();
-		ERR_remove_state(0);
+		ERR_remove_thread_state(NULL);
 		ERR_free_strings();
 		EVP_cleanup();
 		os_free(tls_global->ocsp_stapling_response);
@@ -1102,7 +1114,8 @@ static int tls_match_altsubject_component(X509 *cert, int type,
 {
 	GENERAL_NAME *gen;
 	void *ext;
-	int i, found = 0;
+	int found = 0;
+	stack_index_t i;
 
 	ext = X509_get_ext_d2i(cert, NID_subject_alt_name, NULL, NULL);
 
@@ -1211,7 +1224,7 @@ static int tls_match_suffix(X509 *cert, const char *match)
 
 	ext = X509_get_ext_d2i(cert, NID_subject_alt_name, NULL, NULL);
 
-	for (i = 0; ext && i < sk_GENERAL_NAME_num(ext); i++) {
+	for (i = 0; ext && i < (int) sk_GENERAL_NAME_num(ext); i++) {
 		gen = sk_GENERAL_NAME_value(ext, i);
 		if (gen->type != GEN_DNS)
 			continue;
@@ -1639,7 +1652,7 @@ static int tls_connection_ca_cert(void *_ssl_ctx, struct tls_connection *conn,
 	if (ca_cert && os_strncmp("keystore://", ca_cert, 11) == 0) {
 		BIO *bio = BIO_from_keystore(&ca_cert[11]);
 		STACK_OF(X509_INFO) *stack = NULL;
-		int i;
+		stack_index_t i;
 
 		if (bio) {
 			stack = PEM_X509_INFO_read_bio(bio, NULL, NULL, NULL);
@@ -3386,9 +3399,15 @@ unsigned int tls_capabilities(void *tls_ctx)
  * commented out unless explicitly needed for EAP-FAST in order to be able to
  * build this file with unmodified openssl. */
 
+#ifdef OPENSSL_IS_BORINGSSL
+static int tls_sess_sec_cb(SSL *s, void *secret, int *secret_len,
+			   STACK_OF(SSL_CIPHER) *peer_ciphers,
+			   const SSL_CIPHER **cipher, void *arg)
+#else /* OPENSSL_IS_BORINGSSL */
 static int tls_sess_sec_cb(SSL *s, void *secret, int *secret_len,
 			   STACK_OF(SSL_CIPHER) *peer_ciphers,
 			   SSL_CIPHER **cipher, void *arg)
+#endif /* OPENSSL_IS_BORINGSSL */
 {
 	struct tls_connection *conn = arg;
 	int ret;

src/eap_common/eap_pwd_common.c

@@ -106,9 +106,11 @@ int compute_password_element(EAP_PWD_group *grp, u16 num,
         case 21:
 		nid = NID_secp521r1;
 		break;
+#ifndef OPENSSL_IS_BORINGSSL
         case 25:
 		nid = NID_X9_62_prime192v1;
 		break;
+#endif /* OPENSSL_IS_BORINGSSL */
         case 26:
 		nid = NID_secp224r1;
 		break;