crypto/rsa/rsa_chk.c:184: error: BUFFER_OVERRUN_L3
  Offset added: [8, +oo] Size: [0, 536870848] by call to `BN_mod_inverse`.
Showing all 25 steps of the trace


crypto/rsa/rsa_chk.c:19:1: Parameter `key->q->top`
17.   }
18.   
19. > int RSA_check_key_ex(const RSA *key, BN_GENCB *cb)
20.   {
21.       BIGNUM *i, *j, *k, *l, *m;

crypto/rsa/rsa_chk.c:71:9: Call
69.   
70.       /* q prime? */
71.       if (BN_is_prime_ex(key->q, BN_prime_checks, NULL, cb) != 1) {
              ^
72.           ret = 0;
73.           RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_Q_NOT_PRIME);

crypto/bn/bn_prime.c:145:1: Parameter `a->top`
  143.   }
  144.   
  145. > int BN_is_prime_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed,
  146.                      BN_GENCB *cb)
  147.   {

crypto/bn/bn_prime.c:148:12: Call
  146.                      BN_GENCB *cb)
  147.   {
  148.       return BN_is_prime_fasttest_ex(a, checks, ctx_passed, 0, cb);
                    ^
  149.   }
  150.   

crypto/bn/bn_prime.c:151:1: Parameter `a->top`
    149.   }
    150.   
    151. > int BN_is_prime_fasttest_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed,
    152.                               int do_trial_division, BN_GENCB *cb)
    153.   {

crypto/bn/bn_prime.c:160:9: Call
    158.       BN_MONT_CTX *mont = NULL;
    159.   
    160.       if (BN_cmp(a, BN_value_one()) <= 0)
                   ^
    161.           return 0;
    162.   

crypto/bn/bn_lib.c:539:1: Parameter `a->top`
      537.   }
      538.   
      539. > int BN_cmp(const BIGNUM *a, const BIGNUM *b)
      540.   {
      541.       int i;

crypto/rsa/rsa_chk.c:111:10: Call
109.           goto err;
110.       }
111.       if (!BN_sub(j, key->q, BN_value_one())) {
                ^
112.           ret = -1;
113.           goto err;

crypto/bn/bn_add.c:45:1: Parameter `a->top`
  43.   
  44.   /* signed sub of b from a. */
  45. > int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
  46.   {
  47.       int ret, r_neg, cmp_res;

crypto/rsa/rsa_chk.c:170:14: Call
168.   
169.           /* dmq1 = d mod (q-1)? */
170.           if (!BN_sub(i, key->q, BN_value_one())) {
                    ^
171.               ret = -1;
172.               goto err;

crypto/bn/bn_add.c:45:1: Parameter `a->top`
  43.   
  44.   /* signed sub of b from a. */
  45. > int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)
  46.   {
  47.       int ret, r_neg, cmp_res;

crypto/rsa/rsa_chk.c:184:14: Call
182.   
183.           /* iqmp = q^-1 mod p? */
184.           if (!BN_mod_inverse(i, key->q, key->p, ctx)) {
                    ^
185.               ret = -1;
186.               goto err;

crypto/bn/bn_gcd.c:124:1: Parameter `a->top`
  122.                                           BN_CTX *ctx);
  123.   
  124. > BIGNUM *BN_mod_inverse(BIGNUM *in,
  125.                          const BIGNUM *a, const BIGNUM *n, BN_CTX *ctx)
  126.   {

crypto/bn/bn_gcd.c:129:10: Call
  127.       BIGNUM *rv;
  128.       int noinv;
  129.       rv = int_bn_mod_inverse(in, a, n, ctx, &noinv);
                  ^
  130.       if (noinv)
  131.           BNerr(BN_F_BN_MOD_INVERSE, BN_R_NO_INVERSE);

crypto/bn/bn_gcd.c:135:1: Parameter `a->top`
    133.   }
    134.   
    135. > BIGNUM *int_bn_mod_inverse(BIGNUM *in,
    136.                              const BIGNUM *a, const BIGNUM *n, BN_CTX *ctx,
    137.                              int *pnoinv)

crypto/bn/bn_gcd.c:148:16: Call
    146.       if ((BN_get_flags(a, BN_FLG_CONSTTIME) != 0)
    147.           || (BN_get_flags(n, BN_FLG_CONSTTIME) != 0)) {
    148.           return BN_mod_inverse_no_branch(in, a, n, ctx);
                          ^
    149.       }
    150.   

crypto/bn/bn_gcd.c:451:1: Parameter `a->top`
      449.    * not contain branches that may leak sensitive information.
      450.    */
      451. > static BIGNUM *BN_mod_inverse_no_branch(BIGNUM *in,
      452.                                           const BIGNUM *a, const BIGNUM *n,
      453.                                           BN_CTX *ctx)

crypto/bn/bn_gcd.c:482:9: Call
      480.       BN_one(X);
      481.       BN_zero(Y);
      482.       if (BN_copy(B, a) == NULL)
                     ^
      483.           goto err;
      484.       if (BN_copy(A, n) == NULL)

crypto/bn/bn_lib.c:285:1: <Offset trace>
283.   }
284.   
285. > BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
286.   {
287.       bn_check_top(b);

crypto/bn/bn_lib.c:285:1: Parameter `b->top`
        283.   }
        284.   
        285. > BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
        286.   {
        287.       bn_check_top(b);

crypto/bn/bn_lib.c:285:1: <Length trace>
283.   }
284.   
285. > BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
286.   {
287.       bn_check_top(b);

crypto/bn/bn_lib.c:285:1: Parameter `*a->d`
        283.   }
        284.   
        285. > BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
        286.   {
        287.       bn_check_top(b);

crypto/bn/bn_lib.c:291:9: Call
        289.       if (a == b)
        290.           return a;
        291.       if (bn_wexpand(a, b->top) == NULL)
                       ^
        292.           return NULL;
        293.   

crypto/bn/bn_lib.c:910:1: Parameter `*a->d`
          908.   }
          909.   
          910. > BIGNUM *bn_wexpand(BIGNUM *a, int words)
          911.   {
          912.       return (words <= a->dmax) ? a : bn_expand2(a, words);

crypto/bn/bn_lib.c:295:9: Array access: Offset added: [8, +oo] Size: [0, 536870848] by call to `BN_mod_inverse` 
        293.   
        294.       if (b->top > 0)
        295.           memcpy(a->d, b->d, sizeof(b->d[0]) * b->top);
                       ^
        296.   
        297.       a->top = b->top;

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->top = b->top;
    a->neg = b->neg;
    bn_check_top(a);
    return a;
}
['int RSA_check_key_ex(const RSA *key, BN_GENCB *cb)\n{\n    BIGNUM *i, *j, *k, *l, *m;\n    BN_CTX *ctx;\n    int ret = 1, ex_primes = 0, idx;\n    RSA_PRIME_INFO *pinfo;\n    if (key->p == NULL || key->q == NULL || key->n == NULL\n            || key->e == NULL || key->d == NULL) {\n        RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_VALUE_MISSING);\n        return 0;\n    }\n    if (key->version == RSA_ASN1_VERSION_MULTI) {\n        ex_primes = sk_RSA_PRIME_INFO_num(key->prime_infos);\n        if (ex_primes <= 0\n                || (ex_primes + 2) > rsa_multip_cap(BN_num_bits(key->n))) {\n            RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_INVALID_MULTI_PRIME_KEY);\n            return 0;\n        }\n    }\n    i = BN_new();\n    j = BN_new();\n    k = BN_new();\n    l = BN_new();\n    m = BN_new();\n    ctx = BN_CTX_new();\n    if (i == NULL || j == NULL || k == NULL || l == NULL\n            || m == NULL || ctx == NULL) {\n        ret = -1;\n        RSAerr(RSA_F_RSA_CHECK_KEY_EX, ERR_R_MALLOC_FAILURE);\n        goto err;\n    }\n    if (BN_is_one(key->e)) {\n        ret = 0;\n        RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_BAD_E_VALUE);\n    }\n    if (!BN_is_odd(key->e)) {\n        ret = 0;\n        RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_BAD_E_VALUE);\n    }\n    if (BN_is_prime_ex(key->p, BN_prime_checks, NULL, cb) != 1) {\n        ret = 0;\n        RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_P_NOT_PRIME);\n    }\n    if (BN_is_prime_ex(key->q, BN_prime_checks, NULL, cb) != 1) {\n        ret = 0;\n        RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_Q_NOT_PRIME);\n    }\n    for (idx = 0; idx < ex_primes; idx++) {\n        pinfo = sk_RSA_PRIME_INFO_value(key->prime_infos, idx);\n        if (BN_is_prime_ex(pinfo->r, BN_prime_checks, NULL, cb) != 1) {\n            ret = 0;\n            RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_MP_R_NOT_PRIME);\n        }\n    }\n    if (!BN_mul(i, key->p, key->q, ctx)) {\n        ret = -1;\n        goto err;\n    }\n    for (idx = 0; idx < ex_primes; idx++) {\n        pinfo = sk_RSA_PRIME_INFO_value(key->prime_infos, idx);\n        if (!BN_mul(i, i, pinfo->r, ctx)) {\n            ret = -1;\n            goto err;\n        }\n    }\n    if (BN_cmp(i, key->n) != 0) {\n        ret = 0;\n        if (ex_primes)\n            RSAerr(RSA_F_RSA_CHECK_KEY_EX,\n                   RSA_R_N_DOES_NOT_EQUAL_PRODUCT_OF_PRIMES);\n        else\n            RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_N_DOES_NOT_EQUAL_P_Q);\n    }\n    if (!BN_sub(i, key->p, BN_value_one())) {\n        ret = -1;\n        goto err;\n    }\n    if (!BN_sub(j, key->q, BN_value_one())) {\n        ret = -1;\n        goto err;\n    }\n    if (!BN_mul(l, i, j, ctx)) {\n        ret = -1;\n        goto err;\n    }\n    if (!BN_gcd(m, i, j, ctx)) {\n        ret = -1;\n        goto err;\n    }\n    for (idx = 0; idx < ex_primes; idx++) {\n        pinfo = sk_RSA_PRIME_INFO_value(key->prime_infos, idx);\n        if (!BN_sub(k, pinfo->r, BN_value_one())) {\n            ret = -1;\n            goto err;\n        }\n        if (!BN_mul(l, l, k, ctx)) {\n            ret = -1;\n            goto err;\n        }\n        if (!BN_gcd(m, m, k, ctx)) {\n            ret = -1;\n            goto err;\n        }\n    }\n    if (!BN_div(k, NULL, l, m, ctx)) {\n        ret = -1;\n        goto err;\n    }\n    if (!BN_mod_mul(i, key->d, key->e, k, ctx)) {\n        ret = -1;\n        goto err;\n    }\n    if (!BN_is_one(i)) {\n        ret = 0;\n        RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_D_E_NOT_CONGRUENT_TO_1);\n    }\n    if (key->dmp1 != NULL && key->dmq1 != NULL && key->iqmp != NULL) {\n        if (!BN_sub(i, key->p, BN_value_one())) {\n            ret = -1;\n            goto err;\n        }\n        if (!BN_mod(j, key->d, i, ctx)) {\n            ret = -1;\n            goto err;\n        }\n        if (BN_cmp(j, key->dmp1) != 0) {\n            ret = 0;\n            RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_DMP1_NOT_CONGRUENT_TO_D);\n        }\n        if (!BN_sub(i, key->q, BN_value_one())) {\n            ret = -1;\n            goto err;\n        }\n        if (!BN_mod(j, key->d, i, ctx)) {\n            ret = -1;\n            goto err;\n        }\n        if (BN_cmp(j, key->dmq1) != 0) {\n            ret = 0;\n            RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_DMQ1_NOT_CONGRUENT_TO_D);\n        }\n        if (!BN_mod_inverse(i, key->q, key->p, ctx)) {\n            ret = -1;\n            goto err;\n        }\n        if (BN_cmp(i, key->iqmp) != 0) {\n            ret = 0;\n            RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_IQMP_NOT_INVERSE_OF_Q);\n        }\n    }\n    for (idx = 0; idx < ex_primes; idx++) {\n        pinfo = sk_RSA_PRIME_INFO_value(key->prime_infos, idx);\n        if (!BN_sub(i, pinfo->r, BN_value_one())) {\n            ret = -1;\n            goto err;\n        }\n        if (!BN_mod(j, key->d, i, ctx)) {\n            ret = -1;\n            goto err;\n        }\n        if (BN_cmp(j, pinfo->d) != 0) {\n            ret = 0;\n            RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_MP_EXPONENT_NOT_CONGRUENT_TO_D);\n        }\n        if (!BN_mod_inverse(i, pinfo->pp, pinfo->r, ctx)) {\n            ret = -1;\n            goto err;\n        }\n        if (BN_cmp(i, pinfo->t) != 0) {\n            ret = 0;\n            RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_MP_COEFFICIENT_NOT_INVERSE_OF_R);\n        }\n    }\n err:\n    BN_free(i);\n    BN_free(j);\n    BN_free(k);\n    BN_free(l);\n    BN_free(m);\n    BN_CTX_free(ctx);\n    return ret;\n}', 'int BN_is_prime_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed,\n                   BN_GENCB *cb)\n{\n    return BN_is_prime_fasttest_ex(a, checks, ctx_passed, 0, cb);\n}', 'int BN_is_prime_fasttest_ex(const BIGNUM *a, int checks, BN_CTX *ctx_passed,\n                            int do_trial_division, BN_GENCB *cb)\n{\n    int i, j, ret = -1;\n    int k;\n    BN_CTX *ctx = NULL;\n    BIGNUM *A1, *A1_odd, *check;\n    BN_MONT_CTX *mont = NULL;\n    if (BN_cmp(a, BN_value_one()) <= 0)\n        return 0;\n    if (checks == BN_prime_checks)\n        checks = BN_prime_checks_for_size(BN_num_bits(a));\n    if (!BN_is_odd(a))\n        return BN_is_word(a, 2);\n    if (do_trial_division) {\n        for (i = 1; i < NUMPRIMES; i++) {\n            BN_ULONG mod = BN_mod_word(a, primes[i]);\n            if (mod == (BN_ULONG)-1)\n                goto err;\n            if (mod == 0)\n                return BN_is_word(a, primes[i]);\n        }\n        if (!BN_GENCB_call(cb, 1, -1))\n            goto err;\n    }\n    if (ctx_passed != NULL)\n        ctx = ctx_passed;\n    else if ((ctx = BN_CTX_new()) == NULL)\n        goto err;\n    BN_CTX_start(ctx);\n    A1 = BN_CTX_get(ctx);\n    A1_odd = BN_CTX_get(ctx);\n    check = BN_CTX_get(ctx);\n    if (check == NULL)\n        goto err;\n    if (!BN_copy(A1, a))\n        goto err;\n    if (!BN_sub_word(A1, 1))\n        goto err;\n    if (BN_is_zero(A1)) {\n        ret = 0;\n        goto err;\n    }\n    k = 1;\n    while (!BN_is_bit_set(A1, k))\n        k++;\n    if (!BN_rshift(A1_odd, A1, k))\n        goto err;\n    mont = BN_MONT_CTX_new();\n    if (mont == NULL)\n        goto err;\n    if (!BN_MONT_CTX_set(mont, a, ctx))\n        goto err;\n    for (i = 0; i < checks; i++) {\n        if (!BN_priv_rand_range(check, A1))\n            goto err;\n        if (!BN_add_word(check, 1))\n            goto err;\n        j = witness(check, a, A1, A1_odd, k, ctx, mont);\n        if (j == -1)\n            goto err;\n        if (j) {\n            ret = 0;\n            goto err;\n        }\n        if (!BN_GENCB_call(cb, 1, i))\n            goto err;\n    }\n    ret = 1;\n err:\n    if (ctx != NULL) {\n        BN_CTX_end(ctx);\n        if (ctx_passed == NULL)\n            BN_CTX_free(ctx);\n    }\n    BN_MONT_CTX_free(mont);\n    return ret;\n}', 'int BN_cmp(const BIGNUM *a, const BIGNUM *b)\n{\n    int i;\n    int gt, lt;\n    BN_ULONG t1, t2;\n    if ((a == NULL) || (b == NULL)) {\n        if (a != NULL)\n            return -1;\n        else if (b != NULL)\n            return 1;\n        else\n            return 0;\n    }\n    bn_check_top(a);\n    bn_check_top(b);\n    if (a->neg != b->neg) {\n        if (a->neg)\n            return -1;\n        else\n            return 1;\n    }\n    if (a->neg == 0) {\n        gt = 1;\n        lt = -1;\n    } else {\n        gt = -1;\n        lt = 1;\n    }\n    if (a->top > b->top)\n        return gt;\n    if (a->top < b->top)\n        return lt;\n    for (i = a->top - 1; i >= 0; i--) {\n        t1 = a->d[i];\n        t2 = b->d[i];\n        if (t1 > t2)\n            return gt;\n        if (t1 < t2)\n            return lt;\n    }\n    return 0;\n}', 'int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b)\n{\n    int ret, r_neg, cmp_res;\n    bn_check_top(a);\n    bn_check_top(b);\n    if (a->neg != b->neg) {\n        r_neg = a->neg;\n        ret = BN_uadd(r, a, b);\n    } else {\n        cmp_res = BN_ucmp(a, b);\n        if (cmp_res > 0) {\n            r_neg = a->neg;\n            ret = BN_usub(r, a, b);\n        } else if (cmp_res < 0) {\n            r_neg = !b->neg;\n            ret = BN_usub(r, b, a);\n        } else {\n            r_neg = 0;\n            BN_zero(r);\n            ret = 1;\n        }\n    }\n    r->neg = r_neg;\n    bn_check_top(r);\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}', 'static BIGNUM *BN_mod_inverse_no_branch(BIGNUM *in,\n                                        const BIGNUM *a, const BIGNUM *n,\n                                        BN_CTX *ctx)\n{\n    BIGNUM *A, *B, *X, *Y, *M, *D, *T, *R = NULL;\n    BIGNUM *ret = NULL;\n    int sign;\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         {\n            BIGNUM local_B;\n            bn_init(&local_B);\n            BN_with_flags(&local_B, B, BN_FLG_CONSTTIME);\n            if (!BN_nnmod(B, &local_B, A, ctx))\n                goto err;\n        }\n    }\n    sign = -1;\n    while (!BN_is_zero(B)) {\n        BIGNUM *tmp;\n        {\n            BIGNUM local_A;\n            bn_init(&local_A);\n            BN_with_flags(&local_A, A, BN_FLG_CONSTTIME);\n            if (!BN_div(D, M, &local_A, B, ctx))\n                goto err;\n        }\n        tmp = A;\n        A = B;\n        B = M;\n        if (!BN_mul(tmp, D, X, ctx))\n            goto err;\n        if (!BN_add(tmp, tmp, Y))\n            goto err;\n        M = Y;\n        Y = X;\n        X = tmp;\n        sign = -sign;\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        BNerr(BN_F_BN_MOD_INVERSE_NO_BRANCH, BN_R_NO_INVERSE);\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}', '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->top = b->top;\n    a->neg = b->neg;\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}']