static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)
{
    BN_ULONG *a = NULL;
    if (words > (INT_MAX / (4 * BN_BITS2))) {
        BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_BIGNUM_TOO_LONG);
        return NULL;
    }
    if (BN_get_flags(b, BN_FLG_STATIC_DATA)) {
        BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_EXPAND_ON_STATIC_BIGNUM_DATA);
        return NULL;
    }
    if (BN_get_flags(b, BN_FLG_SECURE))
        a = OPENSSL_secure_zalloc(words * sizeof(*a));
    else
        a = OPENSSL_zalloc(words * sizeof(*a));
    if (a == NULL) {
        BNerr(BN_F_BN_EXPAND_INTERNAL, ERR_R_MALLOC_FAILURE);
        return NULL;
    }
    assert(b->top <= words);
    if (b->top > 0)
        memcpy(a, b->d, sizeof(*a) * b->top);
    return a;
}
['int ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *group,\n                                             EC_POINT *point,\n                                             const BIGNUM *x_, int y_bit,\n                                             BN_CTX *ctx)\n{\n    BN_CTX *new_ctx = NULL;\n    BIGNUM *tmp1, *tmp2, *x, *y;\n    int ret = 0;\n    ERR_clear_error();\n    if (ctx == NULL) {\n        ctx = new_ctx = BN_CTX_new();\n        if (ctx == NULL)\n            return 0;\n    }\n    y_bit = (y_bit != 0);\n    BN_CTX_start(ctx);\n    tmp1 = BN_CTX_get(ctx);\n    tmp2 = BN_CTX_get(ctx);\n    x = BN_CTX_get(ctx);\n    y = BN_CTX_get(ctx);\n    if (y == NULL)\n        goto err;\n    if (!BN_nnmod(x, x_, group->field, ctx))\n        goto err;\n    if (group->meth->field_decode == 0) {\n        if (!group->meth->field_sqr(group, tmp2, x_, ctx))\n            goto err;\n        if (!group->meth->field_mul(group, tmp1, tmp2, x_, ctx))\n            goto err;\n    } else {\n        if (!BN_mod_sqr(tmp2, x_, group->field, ctx))\n            goto err;\n        if (!BN_mod_mul(tmp1, tmp2, x_, group->field, ctx))\n            goto err;\n    }\n    if (group->a_is_minus3) {\n        if (!BN_mod_lshift1_quick(tmp2, x, group->field))\n            goto err;\n        if (!BN_mod_add_quick(tmp2, tmp2, x, group->field))\n            goto err;\n        if (!BN_mod_sub_quick(tmp1, tmp1, tmp2, group->field))\n            goto err;\n    } else {\n        if (group->meth->field_decode) {\n            if (!group->meth->field_decode(group, tmp2, group->a, ctx))\n                goto err;\n            if (!BN_mod_mul(tmp2, tmp2, x, group->field, ctx))\n                goto err;\n        } else {\n            if (!group->meth->field_mul(group, tmp2, group->a, x, ctx))\n                goto err;\n        }\n        if (!BN_mod_add_quick(tmp1, tmp1, tmp2, group->field))\n            goto err;\n    }\n    if (group->meth->field_decode) {\n        if (!group->meth->field_decode(group, tmp2, group->b, ctx))\n            goto err;\n        if (!BN_mod_add_quick(tmp1, tmp1, tmp2, group->field))\n            goto err;\n    } else {\n        if (!BN_mod_add_quick(tmp1, tmp1, group->b, group->field))\n            goto err;\n    }\n    if (!BN_mod_sqrt(y, tmp1, group->field, ctx)) {\n        unsigned long err = ERR_peek_last_error();\n        if (ERR_GET_LIB(err) == ERR_LIB_BN\n            && ERR_GET_REASON(err) == BN_R_NOT_A_SQUARE) {\n            ERR_clear_error();\n            ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES,\n                  EC_R_INVALID_COMPRESSED_POINT);\n        } else\n            ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES,\n                  ERR_R_BN_LIB);\n        goto err;\n    }\n    if (y_bit != BN_is_odd(y)) {\n        if (BN_is_zero(y)) {\n            int kron;\n            kron = BN_kronecker(x, group->field, ctx);\n            if (kron == -2)\n                goto err;\n            if (kron == 1)\n                ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES,\n                      EC_R_INVALID_COMPRESSION_BIT);\n            else\n                ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES,\n                      EC_R_INVALID_COMPRESSED_POINT);\n            goto err;\n        }\n        if (!BN_usub(y, group->field, y))\n            goto err;\n    }\n    if (y_bit != BN_is_odd(y)) {\n        ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES,\n              ERR_R_INTERNAL_ERROR);\n        goto err;\n    }\n    if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx))\n        goto err;\n    ret = 1;\n err:\n    BN_CTX_end(ctx);\n    BN_CTX_free(new_ctx);\n    return ret;\n}', 'int BN_mod_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m,\n               BN_CTX *ctx)\n{\n    BIGNUM *t;\n    int ret = 0;\n    bn_check_top(a);\n    bn_check_top(b);\n    bn_check_top(m);\n    BN_CTX_start(ctx);\n    if ((t = BN_CTX_get(ctx)) == NULL)\n        goto err;\n    if (a == b) {\n        if (!BN_sqr(t, a, ctx))\n            goto err;\n    } else {\n        if (!BN_mul(t, a, b, ctx))\n            goto err;\n    }\n    if (!BN_nnmod(r, t, m, ctx))\n        goto err;\n    bn_check_top(r);\n    ret = 1;\n err:\n    BN_CTX_end(ctx);\n    return ret;\n}', 'int BN_mod_add_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,\n                     const BIGNUM *m)\n{\n    int ret = bn_mod_add_fixed_top(r, a, b, m);\n    if (ret)\n        bn_correct_top(r);\n    return ret;\n}', 'int bn_mod_add_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b,\n                         const BIGNUM *m)\n{\n    size_t i, ai, bi, mtop = m->top;\n    BN_ULONG storage[1024 / BN_BITS2];\n    BN_ULONG carry, temp, mask, *rp, *tp = storage;\n    const BN_ULONG *ap, *bp;\n    if (bn_wexpand(r, mtop) == NULL)\n        return 0;\n    if (mtop > sizeof(storage) / sizeof(storage[0])\n        && (tp = OPENSSL_malloc(mtop * sizeof(BN_ULONG))) == NULL)\n\treturn 0;\n    ap = a->d != NULL ? a->d : tp;\n    bp = b->d != NULL ? b->d : tp;\n    for (i = 0, ai = 0, bi = 0, carry = 0; i < mtop;) {\n        mask = (BN_ULONG)0 - ((i - a->top) >> (8 * sizeof(i) - 1));\n        temp = ((ap[ai] & mask) + carry) & BN_MASK2;\n        carry = (temp < carry);\n        mask = (BN_ULONG)0 - ((i - b->top) >> (8 * sizeof(i) - 1));\n        tp[i] = ((bp[bi] & mask) + temp) & BN_MASK2;\n        carry += (tp[i] < temp);\n        i++;\n        ai += (i - a->dmax) >> (8 * sizeof(i) - 1);\n        bi += (i - b->dmax) >> (8 * sizeof(i) - 1);\n    }\n    rp = r->d;\n    carry -= bn_sub_words(rp, tp, m->d, mtop);\n    for (i = 0; i < mtop; i++) {\n        rp[i] = (carry & tp[i]) | (~carry & rp[i]);\n        ((volatile BN_ULONG *)tp)[i] = 0;\n    }\n    r->top = mtop;\n    r->neg = 0;\n    if (tp != storage)\n        OPENSSL_free(tp);\n    return 1;\n}', 'BIGNUM *bn_wexpand(BIGNUM *a, int words)\n{\n    return (words <= a->dmax) ? a : bn_expand2(a, words);\n}', 'BIGNUM *bn_expand2(BIGNUM *b, int words)\n{\n    if (words > b->dmax) {\n        BN_ULONG *a = bn_expand_internal(b, words);\n        if (!a)\n            return NULL;\n        if (b->d) {\n            OPENSSL_cleanse(b->d, b->dmax * sizeof(b->d[0]));\n            bn_free_d(b);\n        }\n        b->d = a;\n        b->dmax = words;\n    }\n    return b;\n}', 'static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words)\n{\n    BN_ULONG *a = NULL;\n    if (words > (INT_MAX / (4 * BN_BITS2))) {\n        BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_BIGNUM_TOO_LONG);\n        return NULL;\n    }\n    if (BN_get_flags(b, BN_FLG_STATIC_DATA)) {\n        BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_EXPAND_ON_STATIC_BIGNUM_DATA);\n        return NULL;\n    }\n    if (BN_get_flags(b, BN_FLG_SECURE))\n        a = OPENSSL_secure_zalloc(words * sizeof(*a));\n    else\n        a = OPENSSL_zalloc(words * sizeof(*a));\n    if (a == NULL) {\n        BNerr(BN_F_BN_EXPAND_INTERNAL, ERR_R_MALLOC_FAILURE);\n        return NULL;\n    }\n    assert(b->top <= words);\n    if (b->top > 0)\n        memcpy(a, b->d, sizeof(*a) * b->top);\n    return a;\n}']