Guard the _GNU_SOURCE #define.

It is hard to control what flags consumers may try to build us with.
Account for someone adding _GNU_SOURCE to the build line.

Change-Id: I4c931da70a9dccc89382ce9100c228c29d28d4bf
Reviewed-on: https://boringssl-review.googlesource.com/13621
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
(cherry picked from commit e025f30507)

crypto/rand/urandom.c

@@ -12,7 +12,9 @@
  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
 
+#if !defined(_GNU_SOURCE)
 #define _GNU_SOURCE  /* needed for syscall() on Linux. */
+#endif
 
 #include <openssl/rand.h>
 

ssl/CMakeLists.txt

@@ -25,6 +25,7 @@ add_library(
   ssl_file.c
   ssl_lib.c
   ssl_rsa.c
+  ssl_rsa_cc.cc
   ssl_session.c
   ssl_stat.c
   t1_enc.c

ssl/ssl_rsa.c

@@ -153,18 +153,6 @@ static int ssl_set_pkey(CERT *c, EVP_PKEY *pkey) {
   return 1;
 }
 
-int SSL_use_RSAPrivateKey_ASN1(SSL *ssl, const uint8_t *der, size_t der_len) {
-  RSA *rsa = RSA_private_key_from_bytes(der, der_len);
-  if (rsa == NULL) {
-    OPENSSL_PUT_ERROR(SSL, ERR_R_ASN1_LIB);
-    return 0;
-  }
-
-  int ret = SSL_use_RSAPrivateKey(ssl, rsa);
-  RSA_free(rsa);
-  return ret;
-}
-
 int SSL_use_PrivateKey(SSL *ssl, EVP_PKEY *pkey) {
   int ret;
 

ssl/ssl_rsa_cc.cc

@@ -0,0 +1,76 @@
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
+ * All rights reserved.
+ *
+ * This package is an SSL implementation written
+ * by Eric Young (eay@cryptsoft.com).
+ * The implementation was written so as to conform with Netscapes SSL.
+ *
+ * This library is free for commercial and non-commercial use as long as
+ * the following conditions are aheared to.  The following conditions
+ * apply to all code found in this distribution, be it the RC4, RSA,
+ * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
+ * included with this distribution is covered by the same copyright terms
+ * except that the holder is Tim Hudson (tjh@cryptsoft.com).
+ *
+ * Copyright remains Eric Young's, and as such any Copyright notices in
+ * the code are not to be removed.
+ * If this package is used in a product, Eric Young should be given attribution
+ * as the author of the parts of the library used.
+ * This can be in the form of a textual message at program startup or
+ * in documentation (online or textual) provided with the package.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *    "This product includes cryptographic software written by
+ *     Eric Young (eay@cryptsoft.com)"
+ *    The word 'cryptographic' can be left out if the rouines from the library
+ *    being used are not cryptographic related :-).
+ * 4. If you include any Windows specific code (or a derivative thereof) from
+ *    the apps directory (application code) you must include an acknowledgement:
+ *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * The licence and distribution terms for any publically available version or
+ * derivative of this code cannot be changed.  i.e. this code cannot simply be
+ * copied and put under another distribution licence
+ * [including the GNU Public Licence.] */
+
+#include <openssl/ssl.h>
+
+#include <openssl/err.h>
+#include <openssl/rsa.h>
+
+
+/* This function has been converted to C++ to check if all of libssl's
+ * consumers' toolchains are capable of handling C++11. Once all problems in
+ * consumer toolchains are found and fixed, we will convert the rest of
+ * libssl. */
+
+int SSL_use_RSAPrivateKey_ASN1(SSL *ssl, const uint8_t *der, size_t der_len) {
+  bssl::UniquePtr<RSA> rsa(RSA_private_key_from_bytes(der, der_len));
+  if (!rsa) {
+    OPENSSL_PUT_ERROR(SSL, ERR_R_ASN1_LIB);
+    return 0;
+  }
+
+  return SSL_use_RSAPrivateKey(ssl, rsa.get());
+}