Refs #10260 OpenBSD support #25327

runtime/bin/crypto_openbsd.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
-#if defined(TARGET_OS_ANDROID)
+#if defined(TARGET_OS_OPENBSD)
 
 #include <errno.h>  // NOLINT
 #include <fcntl.h>  // NOLINT
 
 #include "bin/fdutils.h"
 #include "bin/crypto.h"
 
 #include "platform/signal_blocker.h"
 
 
 namespace dart {
 namespace bin {
 
+// TODO(mulander): Consider using getentropy(2)

[Ivan Posva, 2016/01/11 23:58:40]

Once you get there, please explain why you do use getentropy(2) and not
arc4random_buf(void *buf, size_t nbytes).

[mulander, 2016/01/12 00:22:45]

You are correct. When that comment was made it was a quick note when I thought
about why I would need to open /dev/urandom if I have a syscall available. That
was some time ago... I did in fact intend to use arc4random_buf after seeing
this http://marc.info/?l=openbsd-tech&m=145176645017540&w=2 on the openbsd
mailing lists. So consider it an outdated comment. arc4random_buf is the target
implementation.

 bool Crypto::GetRandomBytes(intptr_t count, uint8_t* buffer) {
   ThreadSignalBlocker signal_blocker(SIGPROF);
   intptr_t fd = TEMP_FAILURE_RETRY_NO_SIGNAL_BLOCKER(
       open("/dev/urandom", O_RDONLY));
   if (fd < 0) return false;
   intptr_t bytes_read = 0;
   do {
     int res = TEMP_FAILURE_RETRY_NO_SIGNAL_BLOCKER(
         read(fd, buffer + bytes_read, count - bytes_read));
     if (res < 0) {
       int err = errno;
       VOID_TEMP_FAILURE_RETRY_NO_SIGNAL_BLOCKER(close(fd));
       errno = err;
       return false;
     }
     bytes_read += res;
   } while (bytes_read < count);
   VOID_TEMP_FAILURE_RETRY_NO_SIGNAL_BLOCKER(close(fd));
   return true;
 }
 
 }  // namespace bin
 }  // namespace dart
 
-#endif  // defined(TARGET_OS_ANDROID)
+#endif  // defined(TARGET_OS_OPENBSD)