diff options
Diffstat (limited to 'contrib/bearssl/src/inner.h')
| -rw-r--r-- | contrib/bearssl/src/inner.h | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/contrib/bearssl/src/inner.h b/contrib/bearssl/src/inner.h index 986220f0f542..07e1d0a478e8 100644 --- a/contrib/bearssl/src/inner.h +++ b/contrib/bearssl/src/inner.h @@ -309,9 +309,20 @@ * values are documented on: * https://sourceforge.net/p/predef/wiki/OperatingSystems/ * - * TODO: enrich the list of detected system. Also add detection for - * alternate system calls like getentropy(), which are usually - * preferable when available. + * Win32's CryptGenRandom() should be available on Windows systems. + * + * /dev/urandom should work on all Unix-like systems (including macOS X). + * + * getentropy() is present on Linux (Glibc 2.25+), FreeBSD (12.0+) and + * OpenBSD (5.6+). For OpenBSD, there does not seem to be easy to use + * macros to test the minimum version, so we just assume that it is + * recent enough (last version without getentropy() has gone out of + * support in May 2015). + * + * Ideally we should use getentropy() on macOS (10.12+) too, but I don't + * know how to test the exact OS version with preprocessor macros. + * + * TODO: enrich the list of detected system. */ #ifndef BR_USE_URANDOM @@ -328,6 +339,15 @@ #endif #endif +#ifndef BR_USE_GETENTROPY +#if (defined __linux__ \ + && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 25))) \ + || (defined __FreeBSD__ && __FreeBSD__ >= 12) \ + || defined __OpenBSD__ +#define BR_USE_GETENTROPY 1 +#endif +#endif + #ifndef BR_USE_WIN32_RAND #if defined _WIN32 || defined _WIN64 #define BR_USE_WIN32_RAND 1 |