crypto/rsa/rsa_chk.c:144: error: BUFFER_OVERRUN_L3
  Offset: [-1, +oo] Size: [1, +oo] by call to `BN_mod_mul`.
Showing all 29 steps of the trace


crypto/rsa/rsa_chk.c:65:9: Call
63.   
64.       /* p prime? */
65.       if (BN_is_prime_ex(key->p, BN_prime_checks, NULL, cb) != 1) {
              ^
66.           ret = 0;
67.           RSAerr(RSA_F_RSA_CHECK_KEY_EX, RSA_R_P_NOT_PRIME);

crypto/bn/bn_prime.c:145:1: Parameter `ctx_passed->stack.depth`
  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 `ctx_passed->stack.depth`
    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/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 `ctx_passed->stack.depth`
  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 `ctx_passed->stack.depth`
    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/rsa/rsa_chk.c:86:10: Call
84.   
85.       /* n = p*q * r_3...r_i? */
86.       if (!BN_mul(i, key->p, key->q, ctx)) {
               ^
87.           ret = -1;
88.           goto err;

crypto/bn/bn_mul.c:497:1: Parameter `ctx->stack.depth`
  495.   #endif                          /* BN_RECURSION */
  496.   
  497. > int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
  498.   {
  499.       int ret = bn_mul_fixed_top(r, a, b, ctx);

crypto/bn/bn_mul.c:499:15: Call
  497.   int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
  498.   {
  499.       int ret = bn_mul_fixed_top(r, a, b, ctx);
                       ^
  500.   
  501.       bn_correct_top(r);

crypto/bn/bn_mul.c:507:1: Parameter `ctx->stack.depth`
    505.   }
    506.   
    507. > int bn_mul_fixed_top(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
    508.   {
    509.       int ret = 0;

crypto/rsa/rsa_chk.c:144:10: Call
142.           goto err;
143.       }
144.       if (!BN_mod_mul(i, key->d, key->e, k, ctx)) {
                ^
145.           ret = -1;
146.           goto err;

crypto/bn/bn_mod.c:193:1: Parameter `ctx->stack.depth`
  191.   
  192.   /* slow but works */
  193. > int BN_mod_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m,
  194.                  BN_CTX *ctx)
  195.   {

crypto/bn/bn_mod.c:203:5: Call
  201.       bn_check_top(m);
  202.   
  203.       BN_CTX_start(ctx);
             ^
  204.       if ((t = BN_CTX_get(ctx)) == NULL)
  205.           goto err;

crypto/bn/bn_ctx.c:181:1: Parameter `ctx->stack.depth`
    179.   }
    180.   
    181. > void BN_CTX_start(BN_CTX *ctx)
    182.   {
    183.       CTXDBG_ENTRY("BN_CTX_start", ctx);

crypto/bn/bn_mod.c:207:14: Call
  205.           goto err;
  206.       if (a == b) {
  207.           if (!BN_sqr(t, a, ctx))
                      ^
  208.               goto err;
  209.       } else {

crypto/bn/bn_sqr.c:17:1: Parameter `ctx->stack.depth`
    15.    * I've just gone over this and it is now %20 faster on x86 - eay - 27 Jun 96
    16.    */
    17. > int BN_sqr(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
    18.   {
    19.       int ret = bn_sqr_fixed_top(r, a, ctx);

crypto/bn/bn_sqr.c:19:15: Call
    17.   int BN_sqr(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
    18.   {
    19.       int ret = bn_sqr_fixed_top(r, a, ctx);
                        ^
    20.   
    21.       bn_correct_top(r);

crypto/bn/bn_sqr.c:42:5: Call
      40.       }
      41.   
      42.       BN_CTX_start(ctx);
                ^
      43.       rr = (a != r) ? r : BN_CTX_get(ctx);
      44.       tmp = BN_CTX_get(ctx);

crypto/bn/bn_ctx.c:181:1: Parameter `*ctx->stack.indexes`
        179.   }
        180.   
        181. > void BN_CTX_start(BN_CTX *ctx)
        182.   {
        183.       CTXDBG_ENTRY("BN_CTX_start", ctx);

crypto/bn/bn_sqr.c:104:5: Call
      102.       bn_check_top(rr);
      103.       bn_check_top(tmp);
      104.       BN_CTX_end(ctx);
                 ^
      105.       return ret;
      106.   }

crypto/bn/bn_ctx.c:195:1: Parameter `*ctx->stack.indexes`
        193.   }
        194.   
        195. > void BN_CTX_end(BN_CTX *ctx)
        196.   {
        197.       CTXDBG_ENTRY("BN_CTX_end", ctx);

crypto/bn/bn_ctx.c:201:27: Call
        199.           ctx->err_stack--;
        200.       else {
        201.           unsigned int fp = BN_STACK_pop(&ctx->stack);
                                         ^
        202.           /* Does this stack frame have anything to release? */
        203.           if (fp < ctx->used)

crypto/bn/bn_ctx.c:274:1: <Offset trace>
272.   }
273.   
274. > static unsigned int BN_STACK_pop(BN_STACK *st)
275.   {
276.       return st->indexes[--(st->depth)];

crypto/bn/bn_ctx.c:274:1: Parameter `st->depth`
          272.   }
          273.   
          274. > static unsigned int BN_STACK_pop(BN_STACK *st)
          275.   {
          276.       return st->indexes[--(st->depth)];

crypto/bn/bn_ctx.c:274:1: <Length trace>
272.   }
273.   
274. > static unsigned int BN_STACK_pop(BN_STACK *st)
275.   {
276.       return st->indexes[--(st->depth)];

crypto/bn/bn_ctx.c:274:1: Parameter `*st->indexes`
          272.   }
          273.   
          274. > static unsigned int BN_STACK_pop(BN_STACK *st)
          275.   {
          276.       return st->indexes[--(st->depth)];

crypto/bn/bn_ctx.c:276:12: Array access: Offset: [-1, +oo] Size: [1, +oo] by call to `BN_mod_mul` 
          274.   static unsigned int BN_STACK_pop(BN_STACK *st)
          275.   {
          276.       return st->indexes[--(st->depth)];
                            ^
          277.   }
          278.   

static unsigned int BN_STACK_pop(BN_STACK *st)
{
    return st->indexes[--(st->depth)];
}
['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, *A3, *check;\n    BN_MONT_CTX *mont = NULL;\n    if (BN_is_word(a, 2) || BN_is_word(a, 3))\n        return 1;\n    if (!BN_is_odd(a) || 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 (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    A3 = 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) || !BN_sub_word(A1, 1))\n        goto err;\n    if (!BN_copy(A3, a) || !BN_sub_word(A3, 3))\n        goto err;\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, A3) || !BN_add_word(check, 2))\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_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)\n{\n    int ret = bn_mul_fixed_top(r, a, b, ctx);\n    bn_correct_top(r);\n    bn_check_top(r);\n    return ret;\n}', 'int bn_mul_fixed_top(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#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    }\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    rr->neg = a->neg ^ b->neg;\n    rr->flags |= BN_FLG_FIXED_TOP;\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}', '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}', 'void BN_CTX_start(BN_CTX *ctx)\n{\n    CTXDBG_ENTRY("BN_CTX_start", ctx);\n    if (ctx->err_stack || ctx->too_many)\n        ctx->err_stack++;\n    else if (!BN_STACK_push(&ctx->stack, ctx->used)) {\n        BNerr(BN_F_BN_CTX_START, BN_R_TOO_MANY_TEMPORARY_VARIABLES);\n        ctx->err_stack++;\n    }\n    CTXDBG_EXIT(ctx);\n}', 'int BN_sqr(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)\n{\n    int ret = bn_sqr_fixed_top(r, a, ctx);\n    bn_correct_top(r);\n    bn_check_top(r);\n    return ret;\n}', 'int bn_sqr_fixed_top(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)\n{\n    int max, al;\n    int ret = 0;\n    BIGNUM *tmp, *rr;\n    bn_check_top(a);\n    al = a->top;\n    if (al <= 0) {\n        r->top = 0;\n        r->neg = 0;\n        return 1;\n    }\n    BN_CTX_start(ctx);\n    rr = (a != r) ? r : BN_CTX_get(ctx);\n    tmp = BN_CTX_get(ctx);\n    if (rr == NULL || tmp == NULL)\n        goto err;\n    max = 2 * al;\n    if (bn_wexpand(rr, max) == NULL)\n        goto err;\n    if (al == 4) {\n#ifndef BN_SQR_COMBA\n        BN_ULONG t[8];\n        bn_sqr_normal(rr->d, a->d, 4, t);\n#else\n        bn_sqr_comba4(rr->d, a->d);\n#endif\n    } else if (al == 8) {\n#ifndef BN_SQR_COMBA\n        BN_ULONG t[16];\n        bn_sqr_normal(rr->d, a->d, 8, t);\n#else\n        bn_sqr_comba8(rr->d, a->d);\n#endif\n    } else {\n#if defined(BN_RECURSION)\n        if (al < BN_SQR_RECURSIVE_SIZE_NORMAL) {\n            BN_ULONG t[BN_SQR_RECURSIVE_SIZE_NORMAL * 2];\n            bn_sqr_normal(rr->d, a->d, al, t);\n        } else {\n            int j, k;\n            j = BN_num_bits_word((BN_ULONG)al);\n            j = 1 << (j - 1);\n            k = j + j;\n            if (al == j) {\n                if (bn_wexpand(tmp, k * 2) == NULL)\n                    goto err;\n                bn_sqr_recursive(rr->d, a->d, al, tmp->d);\n            } else {\n                if (bn_wexpand(tmp, max) == NULL)\n                    goto err;\n                bn_sqr_normal(rr->d, a->d, al, tmp->d);\n            }\n        }\n#else\n        if (bn_wexpand(tmp, max) == NULL)\n            goto err;\n        bn_sqr_normal(rr->d, a->d, al, tmp->d);\n#endif\n    }\n    rr->neg = 0;\n    rr->top = max;\n    rr->flags |= BN_FLG_FIXED_TOP;\n    if (r != rr && BN_copy(r, rr) == NULL)\n        goto err;\n    ret = 1;\n err:\n    bn_check_top(rr);\n    bn_check_top(tmp);\n    BN_CTX_end(ctx);\n    return ret;\n}', 'void BN_CTX_end(BN_CTX *ctx)\n{\n    CTXDBG_ENTRY("BN_CTX_end", ctx);\n    if (ctx->err_stack)\n        ctx->err_stack--;\n    else {\n        unsigned int fp = BN_STACK_pop(&ctx->stack);\n        if (fp < ctx->used)\n            BN_POOL_release(&ctx->pool, ctx->used - fp);\n        ctx->used = fp;\n        ctx->too_many = 0;\n    }\n    CTXDBG_EXIT(ctx);\n}', 'static unsigned int BN_STACK_pop(BN_STACK *st)\n{\n    return st->indexes[--(st->depth)];\n}']