BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
{
    bn_check_top(b);
    if (a == b)
        return a;
    if (bn_wexpand(a, b->top) == NULL)
        return NULL;
    if (b->top > 0)
        memcpy(a->d, b->d, sizeof(b->d[0]) * b->top);
    a->neg = b->neg;
    a->top = b->top;
    a->flags |= b->flags & BN_FLG_FIXED_TOP;
    bn_check_top(a);
    return a;
}
['static int bn_rsa_fips186_4_find_aux_prob_prime(const BIGNUM *Xp1,\n                                                BIGNUM *p1, BN_CTX *ctx,\n                                                BN_GENCB *cb)\n{\n    int ret = 0;\n    int i = 0;\n    int checks = bn_rsa_fips186_4_aux_prime_MR_min_checks(BN_num_bits(Xp1));\n    if (checks == 0 || BN_copy(p1, Xp1) == NULL)\n        return 0;\n    for(;;) {\n        i++;\n        BN_GENCB_call(cb, 0, i);\n        if (BN_is_prime_fasttest_ex(p1, checks, ctx, 1, cb))\n            break;\n        if (!BN_add_word(p1, 2))\n            goto err;\n    }\n    BN_GENCB_call(cb, 2, i);\n    ret = 1;\nerr:\n    return ret;\n}', 'int BN_num_bits(const BIGNUM *a)\n{\n    int i = a->top - 1;\n    bn_check_top(a);\n    if (BN_is_zero(a))\n        return 0;\n    return ((i * BN_BITS2) + BN_num_bits_word(a->d[i]));\n}', 'int BN_is_zero(const BIGNUM *a)\n{\n    return a->top == 0;\n}', 'BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)\n{\n    bn_check_top(b);\n    if (a == b)\n        return a;\n    if (bn_wexpand(a, b->top) == NULL)\n        return NULL;\n    if (b->top > 0)\n        memcpy(a->d, b->d, sizeof(b->d[0]) * b->top);\n    a->neg = b->neg;\n    a->top = b->top;\n    a->flags |= b->flags & BN_FLG_FIXED_TOP;\n    bn_check_top(a);\n    return a;\n}', 'BIGNUM *bn_wexpand(BIGNUM *a, int words)\n{\n    return (words <= a->dmax) ? a : bn_expand2(a, words);\n}']