// OS randomness for salts and session tokens. (Hashing lives in src/sha256.jai.)

//
// Randomness from the OS.
//

#if OS == .WINDOWS {
    tf_bcrypt :: #system_library "bcrypt";
    BCryptGenRandom :: (algorithm: *void, buffer: *u8, count: u32, flags: u32) -> s32 #foreign tf_bcrypt;

    random_bytes :: (buffer: *u8, count: int) -> bool {
        BCRYPT_USE_SYSTEM_PREFERRED_RNG :: 2;
        return BCryptGenRandom(null, buffer, cast(u32) count, BCRYPT_USE_SYSTEM_PREFERRED_RNG) == 0;
    }
} else {
    tf_libc :: #system_library "libc";
    getrandom :: (buffer: *void, count: u64, flags: u32) -> s64 #foreign tf_libc;

    random_bytes :: (buffer: *u8, count: int) -> bool {
        done := 0;
        while done < count {
            n := getrandom(buffer + done, cast(u64) (count - done), 0);
            if n <= 0 return false;
            done += n;
        }
        return true;
    }
}