diff options
Diffstat (limited to 'src/random.cpp')
| -rw-r--r-- | src/random.cpp | 33 |
1 files changed, 6 insertions, 27 deletions
diff --git a/src/random.cpp b/src/random.cpp index f4c51574cc..54500e6cc6 100644 --- a/src/random.cpp +++ b/src/random.cpp @@ -28,14 +28,10 @@ #include <sys/time.h> #endif -#ifdef HAVE_SYS_GETRANDOM -#include <sys/syscall.h> -#include <linux/random.h> -#endif -#if defined(HAVE_GETENTROPY_RAND) && defined(MAC_OSX) -#include <unistd.h> +#if defined(HAVE_GETRANDOM) || (defined(HAVE_GETENTROPY_RAND) && defined(MAC_OSX)) #include <sys/random.h> #endif + #ifdef HAVE_SYSCTL_ARND #include <sys/sysctl.h> #endif @@ -252,7 +248,7 @@ static void Strengthen(const unsigned char (&seed)[32], SteadyClock::duration du /** Fallback: get 32 bytes of system entropy from /dev/urandom. The most * compatible way to get cryptographic randomness on UNIX-ish platforms. */ -static void GetDevURandom(unsigned char *ent32) +[[maybe_unused]] static void GetDevURandom(unsigned char *ent32) { int f = open("/dev/urandom", O_RDONLY); if (f == -1) { @@ -285,23 +281,14 @@ void GetOSRand(unsigned char *ent32) RandFailure(); } CryptReleaseContext(hProvider, 0); -#elif defined(HAVE_SYS_GETRANDOM) +#elif defined(HAVE_GETRANDOM) /* Linux. From the getrandom(2) man page: * "If the urandom source has been initialized, reads of up to 256 bytes * will always return as many bytes as requested and will not be * interrupted by signals." */ - int rv = syscall(SYS_getrandom, ent32, NUM_OS_RANDOM_BYTES, 0); - if (rv != NUM_OS_RANDOM_BYTES) { - if (rv < 0 && errno == ENOSYS) { - /* Fallback for kernel <3.17: the return value will be -1 and errno - * ENOSYS if the syscall is not available, in that case fall back - * to /dev/urandom. - */ - GetDevURandom(ent32); - } else { - RandFailure(); - } + if (getrandom(ent32, NUM_OS_RANDOM_BYTES, 0) != NUM_OS_RANDOM_BYTES) { + RandFailure(); } #elif defined(__OpenBSD__) /* OpenBSD. From the arc4random(3) man page: @@ -311,16 +298,10 @@ void GetOSRand(unsigned char *ent32) The function call is always successful. */ arc4random_buf(ent32, NUM_OS_RANDOM_BYTES); - // Silence a compiler warning about unused function. - (void)GetDevURandom; #elif defined(HAVE_GETENTROPY_RAND) && defined(MAC_OSX) - /* getentropy() is available on macOS 10.12 and later. - */ if (getentropy(ent32, NUM_OS_RANDOM_BYTES) != 0) { RandFailure(); } - // Silence a compiler warning about unused function. - (void)GetDevURandom; #elif defined(HAVE_SYSCTL_ARND) /* FreeBSD, NetBSD and similar. It is possible for the call to return less * bytes than requested, so need to read in a loop. @@ -334,8 +315,6 @@ void GetOSRand(unsigned char *ent32) } have += len; } while (have < NUM_OS_RANDOM_BYTES); - // Silence a compiler warning about unused function. - (void)GetDevURandom; #else /* Fall back to /dev/urandom if there is no specific method implemented to * get system entropy for this OS. |