-/* external generate function: incorporates continuous RNG test if not
- * in test mode.
- */
-
-int FIPS_drbg_generate(DRBG_CTX *dctx,
- unsigned char *out, size_t outlen,
- int strength, int prediction_resistance,
- const unsigned char *adin, size_t adinlen)
- {
- unsigned char tmp[16], *pout;
- size_t poutlen;
- /* If test mode don't run continuous RNG test */
- if (dctx->flags & DRBG_FLAG_TEST)
- {
- return fips_drbg_generate_internal(dctx, out, outlen,
- strength,
- prediction_resistance,
- adin, adinlen);
- }
- /* If this is the first call generate block and save buffer */
- if (!dctx->lb_valid)
- {
- if (!fips_drbg_generate_internal(dctx, dctx->lb, 16,
- strength, prediction_resistance,
- adin, adinlen))
- return 0;
- dctx->lb_valid = 1;
- }
-
- /* If request less that 16 bytes request 16 in temp buffer */
-
- if (outlen < 16)
- {
- pout = tmp;
- poutlen = 16;
- }
- else
- {
- pout = out;
- poutlen = outlen;
- }
-
- /* Generate data */
- if (!fips_drbg_generate_internal(dctx, pout, poutlen,
- strength, prediction_resistance,
- adin, adinlen))
- return 0;
- /* Compare to last block for continuous PRNG test */
- if (!memcmp(pout, dctx->lb, 16))
- {
- FIPSerr(FIPS_F_FIPS_DRBG_GENERATE, FIPS_R_DRBG_STUCK);
- return 0;
- }
- /* Update last block */
- memcpy(dctx->lb, pout, 16);
- /* Copy to output buffer if needed */
- if (outlen < 16)
- memcpy(out, pout, outlen);
-
- return 1;
-
- }
-