[openssl-users] conversion of RAND_bytes to rand in fips apporved way

[Sudarshan Soma]

 Hi, we have linked FIPS compliant openssl version against our applications.

Now few applications are using libc rand function. For FIPS compliance,
applications have
to call approved SP 800-90A DRBG implementation. I was planning to replace
libc rand with RAND_bytes
for the same.

But rand() returns max value of 32767 .  Is there a recomended way to
convert RAND_bytes to libc rand()
something like this?

unsigned char buf[2];
RAND_bytes(buf,2)
int *rndp = malloc(4);
memcpy(rndp,buf,2);
return (unsigned) ((*rndp) % 32768)


Please suggest . Is there a way to give number of bits instead of bytes  to
RAND_bytes?

Regards,
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