[FFmpeg-devel] [PATCH 2/2] avutil/random_seed: ass support for gcrypt and OpenSSL as source of randomness

[Marton Balint]

On Tue, 4 Jul 2023, James Almer wrote:

> Signed-off-by: James Almer <jamrial at gmail.com>
> ---

In the commit message s/ass/add/

> I put these after /dev/random/ to not change the current behavior of
> av_get_random_seed(), but if either of these are prefered i can move them up.
>
> configure               |  2 +-
> libavutil/random_seed.c | 13 +++++++++++++
> 2 files changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/configure b/configure
> index 107d533b3e..d6e78297fe 100755
> --- a/configure
> +++ b/configure
> @@ -3892,7 +3892,7 @@ avfilter_deps="avutil"
> avfilter_suggest="libm stdatomic"
> avformat_deps="avcodec avutil"
> avformat_suggest="libm network zlib stdatomic"
> -avutil_suggest="clock_gettime ffnvcodec libm libdrm libmfx opencl user32 vaapi vulkan videotoolbox corefoundation corevideo coremedia bcrypt stdatomic"
> +avutil_suggest="clock_gettime ffnvcodec gcrypt libm libdrm libmfx opencl openssl user32 vaapi vulkan videotoolbox corefoundation corevideo coremedia bcrypt stdatomic"
> postproc_deps="avutil gpl"
> postproc_suggest="libm stdatomic"
> swresample_deps="avutil"
> diff --git a/libavutil/random_seed.c b/libavutil/random_seed.c
> index 39fb27c5ad..e8967c0cfe 100644
> --- a/libavutil/random_seed.c
> +++ b/libavutil/random_seed.c
> @@ -30,6 +30,11 @@
> #include <windows.h>
> #include <bcrypt.h>
> #endif
> +#if CONFIG_GCRYPT
> +#include <gcrypt.h>
> +#elif CONFIG_OPENSSL
> +#include <openssl/rand.h>
> +#endif
> #include <fcntl.h>
> #include <math.h>
> #include <time.h>
> @@ -144,6 +149,14 @@ int av_random(uint8_t* buf, size_t len)
>         return 0;
> #endif
>
> +#if CONFIG_GCRYPT
> +    gcry_randomize(buf, len, GCRY_VERY_STRONG_RANDOM);
> +    return 0;
> +#elif CONFIG_OPENSSL
> +    if (RAND_bytes(buf, len))

(RAND_bytes(buf, len) == 1) is more in line with openssl docs.

Regards,
Marton