void bn_correct_top(BIGNUM *a)
{
    BN_ULONG *ftl;
    int tmp_top = a->top;
    if (tmp_top > 0) {
        for (ftl = &(a->d[tmp_top]); tmp_top > 0; tmp_top--) {
            ftl--;
            if (*ftl != 0)
                break;
        }
        a->top = tmp_top;
    }
    if (a->top == 0)
        a->neg = 0;
    bn_pollute(a);
}
['int RSA_X931_derive_ex(RSA *rsa, BIGNUM *p1, BIGNUM *p2, BIGNUM *q1,\n                       BIGNUM *q2, const BIGNUM *Xp1, const BIGNUM *Xp2,\n                       const BIGNUM *Xp, const BIGNUM *Xq1, const BIGNUM *Xq2,\n                       const BIGNUM *Xq, const BIGNUM *e, BN_GENCB *cb)\n{\n    BIGNUM *r0 = NULL, *r1 = NULL, *r2 = NULL, *r3 = NULL;\n    BN_CTX *ctx = NULL, *ctx2 = NULL;\n    int ret = 0;\n    if (!rsa)\n        goto err;\n    ctx = BN_CTX_new();\n    if (ctx == NULL)\n        goto err;\n    BN_CTX_start(ctx);\n    r0 = BN_CTX_get(ctx);\n    r1 = BN_CTX_get(ctx);\n    r2 = BN_CTX_get(ctx);\n    r3 = BN_CTX_get(ctx);\n    if (r3 == NULL)\n        goto err;\n    if (!rsa->e) {\n        rsa->e = BN_dup(e);\n        if (!rsa->e)\n            goto err;\n    } else\n        e = rsa->e;\n    if (Xp && rsa->p == NULL) {\n        rsa->p = BN_new();\n        if (rsa->p == NULL)\n            goto err;\n        if (!BN_X931_derive_prime_ex(rsa->p, p1, p2,\n                                     Xp, Xp1, Xp2, e, ctx, cb))\n            goto err;\n    }\n    if (Xq && rsa->q == NULL) {\n        rsa->q = BN_new();\n        if (rsa->q == NULL)\n            goto err;\n        if (!BN_X931_derive_prime_ex(rsa->q, q1, q2,\n                                     Xq, Xq1, Xq2, e, ctx, cb))\n            goto err;\n    }\n    if (rsa->p == NULL || rsa->q == NULL) {\n        BN_CTX_end(ctx);\n        BN_CTX_free(ctx);\n        return 2;\n    }\n    rsa->n = BN_new();\n    if (rsa->n == NULL)\n        goto err;\n    if (!BN_mul(rsa->n, rsa->p, rsa->q, ctx))\n        goto err;\n    if (!BN_sub(r1, rsa->p, BN_value_one()))\n        goto err;\n    if (!BN_sub(r2, rsa->q, BN_value_one()))\n        goto err;\n    if (!BN_mul(r0, r1, r2, ctx))\n        goto err;\n    if (!BN_gcd(r3, r1, r2, ctx))\n        goto err;\n    if (!BN_div(r0, NULL, r0, r3, ctx))\n        goto err;\n    ctx2 = BN_CTX_new();\n    if (ctx2 == NULL)\n        goto err;\n    rsa->d = BN_mod_inverse(NULL, rsa->e, r0, ctx2);\n    if (rsa->d == NULL)\n        goto err;\n    rsa->dmp1 = BN_new();\n    if (rsa->dmp1 == NULL)\n        goto err;\n    if (!BN_mod(rsa->dmp1, rsa->d, r1, ctx))\n        goto err;\n    rsa->dmq1 = BN_new();\n    if (rsa->dmq1 == NULL)\n        goto err;\n    if (!BN_mod(rsa->dmq1, rsa->d, r2, ctx))\n        goto err;\n    rsa->iqmp = BN_mod_inverse(NULL, rsa->q, rsa->p, ctx2);\n    ret = 1;\n err:\n    if (ctx)\n        BN_CTX_end(ctx);\n    BN_CTX_free(ctx);\n    BN_CTX_free(ctx2);\n    return ret;\n}', 'BIGNUM *BN_dup(const BIGNUM *a)\n{\n    BIGNUM *t;\n    if (a == NULL)\n        return NULL;\n    bn_check_top(a);\n    t = BN_get_flags(a, BN_FLG_SECURE) ? BN_secure_new() : BN_new();\n    if (t == NULL)\n        return NULL;\n    if (!BN_copy(t, a)) {\n        BN_free(t);\n        return NULL;\n    }\n    bn_check_top(t);\n    return t;\n}', 'BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)\n{\n    int i;\n    BN_ULONG *A;\n    const BN_ULONG *B;\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 1\n    A = a->d;\n    B = b->d;\n    for (i = b->top >> 2; i > 0; i--, A += 4, B += 4) {\n        BN_ULONG a0, a1, a2, a3;\n        a0 = B[0];\n        a1 = B[1];\n        a2 = B[2];\n        a3 = B[3];\n        A[0] = a0;\n        A[1] = a1;\n        A[2] = a2;\n        A[3] = a3;\n    }\n    switch (b->top & 3) {\n    case 3:\n        A[2] = B[2];\n    case 2:\n        A[1] = B[1];\n    case 1:\n        A[0] = B[0];\n    case 0:;\n    }\n#else\n    memcpy(a->d, b->d, sizeof(b->d[0]) * b->top);\n#endif\n    a->top = b->top;\n    a->neg = b->neg;\n    bn_check_top(a);\n    return (a);\n}', 'int BN_X931_derive_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2,\n                            const BIGNUM *Xp, const BIGNUM *Xp1,\n                            const BIGNUM *Xp2, const BIGNUM *e, BN_CTX *ctx,\n                            BN_GENCB *cb)\n{\n    int ret = 0;\n    BIGNUM *t, *p1p2, *pm1;\n    if (!BN_is_odd(e))\n        return 0;\n    BN_CTX_start(ctx);\n    if (!p1)\n        p1 = BN_CTX_get(ctx);\n    if (!p2)\n        p2 = BN_CTX_get(ctx);\n    t = BN_CTX_get(ctx);\n    p1p2 = BN_CTX_get(ctx);\n    pm1 = BN_CTX_get(ctx);\n    if (pm1 == NULL)\n        goto err;\n    if (!bn_x931_derive_pi(p1, Xp1, ctx, cb))\n        goto err;\n    if (!bn_x931_derive_pi(p2, Xp2, ctx, cb))\n        goto err;\n    if (!BN_mul(p1p2, p1, p2, ctx))\n        goto err;\n    if (!BN_mod_inverse(p, p2, p1, ctx))\n        goto err;\n    if (!BN_mul(p, p, p2, ctx))\n        goto err;\n    if (!BN_mod_inverse(t, p1, p2, ctx))\n        goto err;\n    if (!BN_mul(t, t, p1, ctx))\n        goto err;\n    if (!BN_sub(p, p, t))\n        goto err;\n    if (p->neg && !BN_add(p, p, p1p2))\n        goto err;\n    if (!BN_mod_sub(p, p, Xp, p1p2, ctx))\n        goto err;\n    if (!BN_add(p, p, Xp))\n        goto err;\n    for (;;) {\n        int i = 1;\n        BN_GENCB_call(cb, 0, i++);\n        if (!BN_copy(pm1, p))\n            goto err;\n        if (!BN_sub_word(pm1, 1))\n            goto err;\n        if (!BN_gcd(t, pm1, e, ctx))\n            goto err;\n        if (BN_is_one(t)) {\n            int r = BN_is_prime_fasttest_ex(p, 50, ctx, 1, cb);\n            if (r < 0)\n                goto err;\n            if (r)\n                break;\n        }\n        if (!BN_add(p, p, p1p2))\n            goto err;\n    }\n    BN_GENCB_call(cb, 3, 0);\n    ret = 1;\n err:\n    BN_CTX_end(ctx);\n    return ret;\n}', 'BIGNUM *BN_mod_inverse(BIGNUM *in,\n                       const BIGNUM *a, const BIGNUM *n, BN_CTX *ctx)\n{\n    BIGNUM *rv;\n    int noinv;\n    rv = int_bn_mod_inverse(in, a, n, ctx, &noinv);\n    if (noinv)\n        BNerr(BN_F_BN_MOD_INVERSE, BN_R_NO_INVERSE);\n    return rv;\n}', 'BIGNUM *int_bn_mod_inverse(BIGNUM *in,\n                           const BIGNUM *a, const BIGNUM *n, BN_CTX *ctx,\n                           int *pnoinv)\n{\n    BIGNUM *A, *B, *X, *Y, *M, *D, *T, *R = NULL;\n    BIGNUM *ret = NULL;\n    int sign;\n    if (pnoinv)\n        *pnoinv = 0;\n    if ((BN_get_flags(a, BN_FLG_CONSTTIME) != 0)\n        || (BN_get_flags(n, BN_FLG_CONSTTIME) != 0)) {\n        return BN_mod_inverse_no_branch(in, a, n, ctx);\n    }\n    bn_check_top(a);\n    bn_check_top(n);\n    BN_CTX_start(ctx);\n    A = BN_CTX_get(ctx);\n    B = BN_CTX_get(ctx);\n    X = BN_CTX_get(ctx);\n    D = BN_CTX_get(ctx);\n    M = BN_CTX_get(ctx);\n    Y = BN_CTX_get(ctx);\n    T = BN_CTX_get(ctx);\n    if (T == NULL)\n        goto err;\n    if (in == NULL)\n        R = BN_new();\n    else\n        R = in;\n    if (R == NULL)\n        goto err;\n    BN_one(X);\n    BN_zero(Y);\n    if (BN_copy(B, a) == NULL)\n        goto err;\n    if (BN_copy(A, n) == NULL)\n        goto err;\n    A->neg = 0;\n    if (B->neg || (BN_ucmp(B, A) >= 0)) {\n        if (!BN_nnmod(B, B, A, ctx))\n            goto err;\n    }\n    sign = -1;\n    if (BN_is_odd(n) && (BN_num_bits(n) <= 2048)) {\n        int shift;\n        while (!BN_is_zero(B)) {\n            shift = 0;\n            while (!BN_is_bit_set(B, shift)) {\n                shift++;\n                if (BN_is_odd(X)) {\n                    if (!BN_uadd(X, X, n))\n                        goto err;\n                }\n                if (!BN_rshift1(X, X))\n                    goto err;\n            }\n            if (shift > 0) {\n                if (!BN_rshift(B, B, shift))\n                    goto err;\n            }\n            shift = 0;\n            while (!BN_is_bit_set(A, shift)) {\n                shift++;\n                if (BN_is_odd(Y)) {\n                    if (!BN_uadd(Y, Y, n))\n                        goto err;\n                }\n                if (!BN_rshift1(Y, Y))\n                    goto err;\n            }\n            if (shift > 0) {\n                if (!BN_rshift(A, A, shift))\n                    goto err;\n            }\n            if (BN_ucmp(B, A) >= 0) {\n                if (!BN_uadd(X, X, Y))\n                    goto err;\n                if (!BN_usub(B, B, A))\n                    goto err;\n            } else {\n                if (!BN_uadd(Y, Y, X))\n                    goto err;\n                if (!BN_usub(A, A, B))\n                    goto err;\n            }\n        }\n    } else {\n        while (!BN_is_zero(B)) {\n            BIGNUM *tmp;\n            if (BN_num_bits(A) == BN_num_bits(B)) {\n                if (!BN_one(D))\n                    goto err;\n                if (!BN_sub(M, A, B))\n                    goto err;\n            } else if (BN_num_bits(A) == BN_num_bits(B) + 1) {\n                if (!BN_lshift1(T, B))\n                    goto err;\n                if (BN_ucmp(A, T) < 0) {\n                    if (!BN_one(D))\n                        goto err;\n                    if (!BN_sub(M, A, B))\n                        goto err;\n                } else {\n                    if (!BN_sub(M, A, T))\n                        goto err;\n                    if (!BN_add(D, T, B))\n                        goto err;\n                    if (BN_ucmp(A, D) < 0) {\n                        if (!BN_set_word(D, 2))\n                            goto err;\n                    } else {\n                        if (!BN_set_word(D, 3))\n                            goto err;\n                        if (!BN_sub(M, M, B))\n                            goto err;\n                    }\n                }\n            } else {\n                if (!BN_div(D, M, A, B, ctx))\n                    goto err;\n            }\n            tmp = A;\n            A = B;\n            B = M;\n            if (BN_is_one(D)) {\n                if (!BN_add(tmp, X, Y))\n                    goto err;\n            } else {\n                if (BN_is_word(D, 2)) {\n                    if (!BN_lshift1(tmp, X))\n                        goto err;\n                } else if (BN_is_word(D, 4)) {\n                    if (!BN_lshift(tmp, X, 2))\n                        goto err;\n                } else if (D->top == 1) {\n                    if (!BN_copy(tmp, X))\n                        goto err;\n                    if (!BN_mul_word(tmp, D->d[0]))\n                        goto err;\n                } else {\n                    if (!BN_mul(tmp, D, X, ctx))\n                        goto err;\n                }\n                if (!BN_add(tmp, tmp, Y))\n                    goto err;\n            }\n            M = Y;\n            Y = X;\n            X = tmp;\n            sign = -sign;\n        }\n    }\n    if (sign < 0) {\n        if (!BN_sub(Y, n, Y))\n            goto err;\n    }\n    if (BN_is_one(A)) {\n        if (!Y->neg && BN_ucmp(Y, n) < 0) {\n            if (!BN_copy(R, Y))\n                goto err;\n        } else {\n            if (!BN_nnmod(R, Y, n, ctx))\n                goto err;\n        }\n    } else {\n        if (pnoinv)\n            *pnoinv = 1;\n        goto err;\n    }\n    ret = R;\n err:\n    if ((ret == NULL) && (in == NULL))\n        BN_free(R);\n    BN_CTX_end(ctx);\n    bn_check_top(ret);\n    return (ret);\n}', 'int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)\n{\n    int ret = 0;\n    int top, al, bl;\n    BIGNUM *rr;\n#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)\n    int i;\n#endif\n#ifdef BN_RECURSION\n    BIGNUM *t = NULL;\n    int j = 0, k;\n#endif\n    bn_check_top(a);\n    bn_check_top(b);\n    bn_check_top(r);\n    al = a->top;\n    bl = b->top;\n    if ((al == 0) || (bl == 0)) {\n        BN_zero(r);\n        return (1);\n    }\n    top = al + bl;\n    BN_CTX_start(ctx);\n    if ((r == a) || (r == b)) {\n        if ((rr = BN_CTX_get(ctx)) == NULL)\n            goto err;\n    } else\n        rr = r;\n    rr->neg = a->neg ^ b->neg;\n#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)\n    i = al - bl;\n#endif\n#ifdef BN_MUL_COMBA\n    if (i == 0) {\n# if 0\n        if (al == 4) {\n            if (bn_wexpand(rr, 8) == NULL)\n                goto err;\n            rr->top = 8;\n            bn_mul_comba4(rr->d, a->d, b->d);\n            goto end;\n        }\n# endif\n        if (al == 8) {\n            if (bn_wexpand(rr, 16) == NULL)\n                goto err;\n            rr->top = 16;\n            bn_mul_comba8(rr->d, a->d, b->d);\n            goto end;\n        }\n    }\n#endif\n#ifdef BN_RECURSION\n    if ((al >= BN_MULL_SIZE_NORMAL) && (bl >= BN_MULL_SIZE_NORMAL)) {\n        if (i >= -1 && i <= 1) {\n            if (i >= 0) {\n                j = BN_num_bits_word((BN_ULONG)al);\n            }\n            if (i == -1) {\n                j = BN_num_bits_word((BN_ULONG)bl);\n            }\n            j = 1 << (j - 1);\n            assert(j <= al || j <= bl);\n            k = j + j;\n            t = BN_CTX_get(ctx);\n            if (t == NULL)\n                goto err;\n            if (al > j || bl > j) {\n                if (bn_wexpand(t, k * 4) == NULL)\n                    goto err;\n                if (bn_wexpand(rr, k * 4) == NULL)\n                    goto err;\n                bn_mul_part_recursive(rr->d, a->d, b->d,\n                                      j, al - j, bl - j, t->d);\n            } else {\n                if (bn_wexpand(t, k * 2) == NULL)\n                    goto err;\n                if (bn_wexpand(rr, k * 2) == NULL)\n                    goto err;\n                bn_mul_recursive(rr->d, a->d, b->d, j, al - j, bl - j, t->d);\n            }\n            rr->top = top;\n            goto end;\n        }\n# if 0\n        if (i == 1 && !BN_get_flags(b, BN_FLG_STATIC_DATA)) {\n            BIGNUM *tmp_bn = (BIGNUM *)b;\n            if (bn_wexpand(tmp_bn, al) == NULL)\n                goto err;\n            tmp_bn->d[bl] = 0;\n            bl++;\n            i--;\n        } else if (i == -1 && !BN_get_flags(a, BN_FLG_STATIC_DATA)) {\n            BIGNUM *tmp_bn = (BIGNUM *)a;\n            if (bn_wexpand(tmp_bn, bl) == NULL)\n                goto err;\n            tmp_bn->d[al] = 0;\n            al++;\n            i++;\n        }\n        if (i == 0) {\n            j = BN_num_bits_word((BN_ULONG)al);\n            j = 1 << (j - 1);\n            k = j + j;\n            t = BN_CTX_get(ctx);\n            if (al == j) {\n                if (bn_wexpand(t, k * 2) == NULL)\n                    goto err;\n                if (bn_wexpand(rr, k * 2) == NULL)\n                    goto err;\n                bn_mul_recursive(rr->d, a->d, b->d, al, t->d);\n            } else {\n                if (bn_wexpand(t, k * 4) == NULL)\n                    goto err;\n                if (bn_wexpand(rr, k * 4) == NULL)\n                    goto err;\n                bn_mul_part_recursive(rr->d, a->d, b->d, al - j, j, t->d);\n            }\n            rr->top = top;\n            goto end;\n        }\n# endif\n    }\n#endif\n    if (bn_wexpand(rr, top) == NULL)\n        goto err;\n    rr->top = top;\n    bn_mul_normal(rr->d, a->d, al, b->d, bl);\n#if defined(BN_MUL_COMBA) || defined(BN_RECURSION)\n end:\n#endif\n    bn_correct_top(rr);\n    if (r != rr && BN_copy(r, rr) == NULL)\n        goto err;\n    ret = 1;\n err:\n    bn_check_top(r);\n    BN_CTX_end(ctx);\n    return (ret);\n}', 'void bn_correct_top(BIGNUM *a)\n{\n    BN_ULONG *ftl;\n    int tmp_top = a->top;\n    if (tmp_top > 0) {\n        for (ftl = &(a->d[tmp_top]); tmp_top > 0; tmp_top--) {\n            ftl--;\n            if (*ftl != 0)\n                break;\n        }\n        a->top = tmp_top;\n    }\n    if (a->top == 0)\n        a->neg = 0;\n    bn_pollute(a);\n}']