int ctr_instantiate(RAND_DRBG *drbg,
                    const unsigned char *entropy, size_t entropylen,
                    const unsigned char *nonce, size_t noncelen,
                    const unsigned char *pers, size_t perslen)
{
    RAND_DRBG_CTR *ctr = &drbg->ctr;
    if (entropy == NULL)
        return 0;
    memset(ctr->K, 0, sizeof(ctr->K));
    memset(ctr->V, 0, sizeof(ctr->V));
    AES_set_encrypt_key(ctr->K, drbg->strength, &ctr->ks);
    ctr_update(drbg, entropy, entropylen, pers, perslen, nonce, noncelen);
    return 1;
}
['int ctr_instantiate(RAND_DRBG *drbg,\n                    const unsigned char *entropy, size_t entropylen,\n                    const unsigned char *nonce, size_t noncelen,\n                    const unsigned char *pers, size_t perslen)\n{\n    RAND_DRBG_CTR *ctr = &drbg->ctr;\n    if (entropy == NULL)\n        return 0;\n    memset(ctr->K, 0, sizeof(ctr->K));\n    memset(ctr->V, 0, sizeof(ctr->V));\n    AES_set_encrypt_key(ctr->K, drbg->strength, &ctr->ks);\n    ctr_update(drbg, entropy, entropylen, pers, perslen, nonce, noncelen);\n    return 1;\n}']