crypto/bn/bn_blind.c:275: error: INTEGER_OVERFLOW_L2
  ([0, +oo] - 1):unsigned32 by call to `int_bn_mod_inverse`.
Showing all 41 steps of the trace


crypto/bn/bn_blind.c:233:1: Parameter `ctx->stack.depth`
231.   }
232.   
233. > BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,
234.                                         const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,
235.                                         int (*bn_mod_exp) (BIGNUM *r,

crypto/bn/bn_blind.c:275:13: Call
273.           if (!BN_priv_rand_range(ret->A, ret->mod))
274.               goto err;
275.           if (int_bn_mod_inverse(ret->Ai, ret->A, ret->mod, ctx, &rv))
                   ^
276.               break;
277.   

crypto/bn/bn_gcd.c:135:1: Parameter `ctx->stack.depth`
  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:155:16: Call
  153.       if ((BN_get_flags(a, BN_FLG_CONSTTIME) != 0)
  154.           || (BN_get_flags(n, BN_FLG_CONSTTIME) != 0)) {
  155.           return BN_mod_inverse_no_branch(in, a, n, ctx);
                        ^
  156.       }
  157.   

crypto/bn/bn_gcd.c:458:1: Parameter `ctx->stack.depth`
    456.    * not contain branches that may leak sensitive information.
    457.    */
    458. > static BIGNUM *BN_mod_inverse_no_branch(BIGNUM *in,
    459.                                           const BIGNUM *a, const BIGNUM *n,
    460.                                           BN_CTX *ctx)

crypto/bn/bn_gcd.c:469:5: Call
    467.       bn_check_top(n);
    468.   
    469.       BN_CTX_start(ctx);
               ^
    470.       A = BN_CTX_get(ctx);
    471.       B = BN_CTX_get(ctx);

crypto/bn/bn_ctx.c:171:1: Parameter `ctx->stack.depth`
      169.   }
      170.   
      171. > void BN_CTX_start(BN_CTX *ctx)
      172.   {
      173.       CTXDBG("ENTER BN_CTX_start()", ctx);

crypto/bn/bn_gcd.c:470:9: Call
    468.   
    469.       BN_CTX_start(ctx);
    470.       A = BN_CTX_get(ctx);
                   ^
    471.       B = BN_CTX_get(ctx);
    472.       X = BN_CTX_get(ctx);

crypto/bn/bn_ctx.c:202:1: Parameter `ctx->stack.depth`
      200.   }
      201.   
      202. > BIGNUM *BN_CTX_get(BN_CTX *ctx)
      203.   {
      204.       BIGNUM *ret;

crypto/bn/bn_gcd.c:471:9: Call
    469.       BN_CTX_start(ctx);
    470.       A = BN_CTX_get(ctx);
    471.       B = BN_CTX_get(ctx);
                   ^
    472.       X = BN_CTX_get(ctx);
    473.       D = BN_CTX_get(ctx);

crypto/bn/bn_ctx.c:202:1: Parameter `ctx->stack.depth`
      200.   }
      201.   
      202. > BIGNUM *BN_CTX_get(BN_CTX *ctx)
      203.   {
      204.       BIGNUM *ret;

crypto/bn/bn_gcd.c:472:9: Call
    470.       A = BN_CTX_get(ctx);
    471.       B = BN_CTX_get(ctx);
    472.       X = BN_CTX_get(ctx);
                   ^
    473.       D = BN_CTX_get(ctx);
    474.       M = BN_CTX_get(ctx);

crypto/bn/bn_ctx.c:202:1: Parameter `ctx->stack.depth`
      200.   }
      201.   
      202. > BIGNUM *BN_CTX_get(BN_CTX *ctx)
      203.   {
      204.       BIGNUM *ret;

crypto/bn/bn_gcd.c:473:9: Call
    471.       B = BN_CTX_get(ctx);
    472.       X = BN_CTX_get(ctx);
    473.       D = BN_CTX_get(ctx);
                   ^
    474.       M = BN_CTX_get(ctx);
    475.       Y = BN_CTX_get(ctx);

crypto/bn/bn_ctx.c:202:1: Parameter `ctx->stack.depth`
      200.   }
      201.   
      202. > BIGNUM *BN_CTX_get(BN_CTX *ctx)
      203.   {
      204.       BIGNUM *ret;

crypto/bn/bn_gcd.c:474:9: Call
    472.       X = BN_CTX_get(ctx);
    473.       D = BN_CTX_get(ctx);
    474.       M = BN_CTX_get(ctx);
                   ^
    475.       Y = BN_CTX_get(ctx);
    476.       T = BN_CTX_get(ctx);

crypto/bn/bn_ctx.c:202:1: Parameter `ctx->stack.depth`
      200.   }
      201.   
      202. > BIGNUM *BN_CTX_get(BN_CTX *ctx)
      203.   {
      204.       BIGNUM *ret;

crypto/bn/bn_gcd.c:475:9: Call
    473.       D = BN_CTX_get(ctx);
    474.       M = BN_CTX_get(ctx);
    475.       Y = BN_CTX_get(ctx);
                   ^
    476.       T = BN_CTX_get(ctx);
    477.       if (T == NULL)

crypto/bn/bn_ctx.c:202:1: Parameter `ctx->stack.depth`
      200.   }
      201.   
      202. > BIGNUM *BN_CTX_get(BN_CTX *ctx)
      203.   {
      204.       BIGNUM *ret;

crypto/bn/bn_gcd.c:476:9: Call
    474.       M = BN_CTX_get(ctx);
    475.       Y = BN_CTX_get(ctx);
    476.       T = BN_CTX_get(ctx);
                   ^
    477.       if (T == NULL)
    478.           goto err;

crypto/bn/bn_ctx.c:202:1: Parameter `ctx->stack.depth`
      200.   }
      201.   
      202. > BIGNUM *BN_CTX_get(BN_CTX *ctx)
      203.   {
      204.       BIGNUM *ret;

crypto/bn/bn_gcd.c:504:18: Call
    502.               bn_init(&local_B);
    503.               BN_with_flags(&local_B, B, BN_FLG_CONSTTIME);
    504.               if (!BN_nnmod(B, &local_B, A, ctx))
                            ^
    505.                   goto err;
    506.               /* Ensure local_B goes out of scope before any further use of B */

crypto/bn/bn_mod.c:13:1: Parameter `ctx->stack.depth`
      11.   #include "bn_lcl.h"
      12.   
      13. > int BN_nnmod(BIGNUM *r, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx)
      14.   {
      15.       /*

crypto/bn/bn_mod.c:20:11: Call
      18.        */
      19.   
      20.       if (!(BN_mod(r, m, d, ctx)))
                      ^
      21.           return 0;
      22.       if (!r->neg)

crypto/bn/bn_div.c:209:1: Parameter `ctx->stack.depth`
        207.    * If 'dv' or 'rm' is NULL, the respective value is not returned.
        208.    */
        209. > int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
        210.              BN_CTX *ctx)
        211.   {

crypto/bn/bn_div.c:229:11: Call
        227.       }
        228.   
        229.       ret = bn_div_fixed_top(dv, rm, num, divisor, ctx);
                         ^
        230.   
        231.       if (ret) {

crypto/bn/bn_div.c:264:1: Parameter `ctx->stack.depth`
          262.    *       divisor's length is considered public;
          263.    */
          264. > int bn_div_fixed_top(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num,
          265.                        const BIGNUM *divisor, BN_CTX *ctx)
          266.   {

crypto/bn/bn_div.c:280:5: Call
          278.       bn_check_top(rm);
          279.   
          280.       BN_CTX_start(ctx);
                     ^
          281.       res = (dv == NULL) ? BN_CTX_get(ctx) : dv;
          282.       tmp = BN_CTX_get(ctx);

crypto/bn/bn_ctx.c:171:1: Parameter `ctx->stack.depth`
            169.   }
            170.   
            171. > void BN_CTX_start(BN_CTX *ctx)
            172.   {
            173.       CTXDBG("ENTER BN_CTX_start()", ctx);

crypto/bn/bn_div.c:282:11: Call
          280.       BN_CTX_start(ctx);
          281.       res = (dv == NULL) ? BN_CTX_get(ctx) : dv;
          282.       tmp = BN_CTX_get(ctx);
                           ^
          283.       snum = BN_CTX_get(ctx);
          284.       sdiv = BN_CTX_get(ctx);

crypto/bn/bn_ctx.c:202:1: Parameter `ctx->stack.depth`
            200.   }
            201.   
            202. > BIGNUM *BN_CTX_get(BN_CTX *ctx)
            203.   {
            204.       BIGNUM *ret;

crypto/bn/bn_div.c:283:12: Call
          281.       res = (dv == NULL) ? BN_CTX_get(ctx) : dv;
          282.       tmp = BN_CTX_get(ctx);
          283.       snum = BN_CTX_get(ctx);
                            ^
          284.       sdiv = BN_CTX_get(ctx);
          285.       if (sdiv == NULL)

crypto/bn/bn_ctx.c:202:1: Parameter `ctx->stack.depth`
            200.   }
            201.   
            202. > BIGNUM *BN_CTX_get(BN_CTX *ctx)
            203.   {
            204.       BIGNUM *ret;

crypto/bn/bn_div.c:284:12: Call
          282.       tmp = BN_CTX_get(ctx);
          283.       snum = BN_CTX_get(ctx);
          284.       sdiv = BN_CTX_get(ctx);
                            ^
          285.       if (sdiv == NULL)
          286.           goto err;

crypto/bn/bn_ctx.c:202:1: Parameter `ctx->stack.depth`
            200.   }
            201.   
            202. > BIGNUM *BN_CTX_get(BN_CTX *ctx)
            203.   {
            204.       BIGNUM *ret;

crypto/bn/bn_div.c:450:5: Call
          448.       if (rm != NULL)
          449.           bn_rshift_fixed_top(rm, snum, norm_shift);
          450.       BN_CTX_end(ctx);
                     ^
          451.       return 1;
          452.    err:

crypto/bn/bn_ctx.c:185:1: Parameter `ctx->stack.depth`
            183.   }
            184.   
            185. > void BN_CTX_end(BN_CTX *ctx)
            186.   {
            187.       CTXDBG("ENTER BN_CTX_end()", ctx);

crypto/bn/bn_ctx.c:191:27: Call
            189.           ctx->err_stack--;
            190.       else {
            191.           unsigned int fp = BN_STACK_pop(&ctx->stack);
                                             ^
            192.           /* Does this stack frame have anything to release? */
            193.           if (fp < ctx->used)

crypto/bn/bn_ctx.c:266:1: <LHS trace>
264.   }
265.   
266. > static unsigned int BN_STACK_pop(BN_STACK *st)
267.   {
268.       return st->indexes[--(st->depth)];

crypto/bn/bn_ctx.c:266:1: Parameter `st->depth`
              264.   }
              265.   
              266. > static unsigned int BN_STACK_pop(BN_STACK *st)
              267.   {
              268.       return st->indexes[--(st->depth)];

crypto/bn/bn_ctx.c:268:12: Binary operation: ([0, +oo] - 1):unsigned32 by call to `int_bn_mod_inverse` 
              266.   static unsigned int BN_STACK_pop(BN_STACK *st)
              267.   {
              268.       return st->indexes[--(st->depth)];
                                ^
              269.   }
              270.   

static unsigned int BN_STACK_pop(BN_STACK *st)
{
    return st->indexes[--(st->depth)];
}
['BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,\n                                      const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,\n                                      int (*bn_mod_exp) (BIGNUM *r,\n                                                         const BIGNUM *a,\n                                                         const BIGNUM *p,\n                                                         const BIGNUM *m,\n                                                         BN_CTX *ctx,\n                                                         BN_MONT_CTX *m_ctx),\n                                      BN_MONT_CTX *m_ctx)\n{\n    int retry_counter = 32;\n    BN_BLINDING *ret = NULL;\n    if (b == NULL)\n        ret = BN_BLINDING_new(NULL, NULL, m);\n    else\n        ret = b;\n    if (ret == NULL)\n        goto err;\n    if (ret->A == NULL && (ret->A = BN_new()) == NULL)\n        goto err;\n    if (ret->Ai == NULL && (ret->Ai = BN_new()) == NULL)\n        goto err;\n    if (e != NULL) {\n        BN_free(ret->e);\n        ret->e = BN_dup(e);\n    }\n    if (ret->e == NULL)\n        goto err;\n    if (bn_mod_exp != NULL)\n        ret->bn_mod_exp = bn_mod_exp;\n    if (m_ctx != NULL)\n        ret->m_ctx = m_ctx;\n    do {\n        int rv;\n        if (!BN_priv_rand_range(ret->A, ret->mod))\n            goto err;\n        if (int_bn_mod_inverse(ret->Ai, ret->A, ret->mod, ctx, &rv))\n            break;\n        if (!rv)\n            goto err;\n        if (retry_counter-- == 0) {\n            BNerr(BN_F_BN_BLINDING_CREATE_PARAM, BN_R_TOO_MANY_ITERATIONS);\n            goto err;\n        }\n    } while (1);\n    if (ret->bn_mod_exp != NULL && ret->m_ctx != NULL) {\n        if (!ret->bn_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx, ret->m_ctx))\n            goto err;\n    } else {\n        if (!BN_mod_exp(ret->A, ret->A, ret->e, ret->mod, ctx))\n            goto err;\n    }\n    if (ret->m_ctx != NULL) {\n        if (!bn_to_mont_fixed_top(ret->Ai, ret->Ai, ret->m_ctx, ctx)\n            || !bn_to_mont_fixed_top(ret->A, ret->A, ret->m_ctx, ctx))\n            goto err;\n    }\n    return ret;\n err:\n    if (b == NULL) {\n        BN_BLINDING_free(ret);\n        ret = NULL;\n    }\n    return ret;\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 (BN_abs_is_word(n, 1) || BN_is_zero(n)) {\n        if (pnoinv != NULL)\n            *pnoinv = 1;\n        return NULL;\n    }\n    if (pnoinv != NULL)\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}', 'void BN_CTX_start(BN_CTX *ctx)\n{\n    CTXDBG("ENTER 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("LEAVE BN_CTX_start()", ctx);\n}', 'BIGNUM *BN_CTX_get(BN_CTX *ctx)\n{\n    BIGNUM *ret;\n    CTXDBG("ENTER BN_CTX_get()", ctx);\n    if (ctx->err_stack || ctx->too_many)\n        return NULL;\n    if ((ret = BN_POOL_get(&ctx->pool, ctx->flags)) == NULL) {\n        ctx->too_many = 1;\n        BNerr(BN_F_BN_CTX_GET, BN_R_TOO_MANY_TEMPORARY_VARIABLES);\n        return NULL;\n    }\n    BN_zero(ret);\n    ret->flags &= (~BN_FLG_CONSTTIME);\n    ctx->used++;\n    CTXDBG("LEAVE BN_CTX_get()", ctx);\n    return ret;\n}', 'int BN_nnmod(BIGNUM *r, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx)\n{\n    if (!(BN_mod(r, m, d, ctx)))\n        return 0;\n    if (!r->neg)\n        return 1;\n    return (d->neg ? BN_sub : BN_add) (r, r, d);\n}', 'int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,\n           BN_CTX *ctx)\n{\n    int ret;\n    if (BN_is_zero(divisor)) {\n        BNerr(BN_F_BN_DIV, BN_R_DIV_BY_ZERO);\n        return 0;\n    }\n    if (divisor->d[divisor->top - 1] == 0) {\n        BNerr(BN_F_BN_DIV, BN_R_NOT_INITIALIZED);\n        return 0;\n    }\n    ret = bn_div_fixed_top(dv, rm, num, divisor, ctx);\n    if (ret) {\n        if (dv != NULL)\n            bn_correct_top(dv);\n        if (rm != NULL)\n            bn_correct_top(rm);\n    }\n    return ret;\n}', 'int bn_div_fixed_top(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num,\n                     const BIGNUM *divisor, BN_CTX *ctx)\n{\n    int norm_shift, i, j, loop;\n    BIGNUM *tmp, *snum, *sdiv, *res;\n    BN_ULONG *resp, *wnum, *wnumtop;\n    BN_ULONG d0, d1;\n    int num_n, div_n;\n    assert(divisor->top > 0 && divisor->d[divisor->top - 1] != 0);\n    bn_check_top(num);\n    bn_check_top(divisor);\n    bn_check_top(dv);\n    bn_check_top(rm);\n    BN_CTX_start(ctx);\n    res = (dv == NULL) ? BN_CTX_get(ctx) : dv;\n    tmp = BN_CTX_get(ctx);\n    snum = BN_CTX_get(ctx);\n    sdiv = BN_CTX_get(ctx);\n    if (sdiv == NULL)\n        goto err;\n    if (!BN_copy(sdiv, divisor))\n        goto err;\n    norm_shift = bn_left_align(sdiv);\n    sdiv->neg = 0;\n    if (!(bn_lshift_fixed_top(snum, num, norm_shift)))\n        goto err;\n    div_n = sdiv->top;\n    num_n = snum->top;\n    if (num_n <= div_n) {\n        if (bn_wexpand(snum, div_n + 1) == NULL)\n            goto err;\n        memset(&(snum->d[num_n]), 0, (div_n - num_n + 1) * sizeof(BN_ULONG));\n        snum->top = num_n = div_n + 1;\n    }\n    loop = num_n - div_n;\n    wnum = &(snum->d[loop]);\n    wnumtop = &(snum->d[num_n - 1]);\n    d0 = sdiv->d[div_n - 1];\n    d1 = (div_n == 1) ? 0 : sdiv->d[div_n - 2];\n    if (!bn_wexpand(res, loop))\n        goto err;\n    res->neg = (num->neg ^ divisor->neg);\n    res->top = loop;\n    res->flags |= BN_FLG_FIXED_TOP;\n    resp = &(res->d[loop]);\n    if (!bn_wexpand(tmp, (div_n + 1)))\n        goto err;\n    for (i = 0; i < loop; i++, wnumtop--) {\n        BN_ULONG q, l0;\n# if defined(BN_DIV3W)\n        q = bn_div_3_words(wnumtop, d1, d0);\n# else\n        BN_ULONG n0, n1, rem = 0;\n        n0 = wnumtop[0];\n        n1 = wnumtop[-1];\n        if (n0 == d0)\n            q = BN_MASK2;\n        else {\n            BN_ULONG n2 = (wnumtop == wnum) ? 0 : wnumtop[-2];\n#  ifdef BN_LLONG\n            BN_ULLONG t2;\n#   if defined(BN_LLONG) && defined(BN_DIV2W) && !defined(bn_div_words)\n            q = (BN_ULONG)(((((BN_ULLONG) n0) << BN_BITS2) | n1) / d0);\n#   else\n            q = bn_div_words(n0, n1, d0);\n#   endif\n#   ifndef REMAINDER_IS_ALREADY_CALCULATED\n            rem = (n1 - q * d0) & BN_MASK2;\n#   endif\n            t2 = (BN_ULLONG) d1 *q;\n            for (;;) {\n                if (t2 <= ((((BN_ULLONG) rem) << BN_BITS2) | n2))\n                    break;\n                q--;\n                rem += d0;\n                if (rem < d0)\n                    break;\n                t2 -= d1;\n            }\n#  else\n            BN_ULONG t2l, t2h;\n            q = bn_div_words(n0, n1, d0);\n#   ifndef REMAINDER_IS_ALREADY_CALCULATED\n            rem = (n1 - q * d0) & BN_MASK2;\n#   endif\n#   if defined(BN_UMULT_LOHI)\n            BN_UMULT_LOHI(t2l, t2h, d1, q);\n#   elif defined(BN_UMULT_HIGH)\n            t2l = d1 * q;\n            t2h = BN_UMULT_HIGH(d1, q);\n#   else\n            {\n                BN_ULONG ql, qh;\n                t2l = LBITS(d1);\n                t2h = HBITS(d1);\n                ql = LBITS(q);\n                qh = HBITS(q);\n                mul64(t2l, t2h, ql, qh);\n            }\n#   endif\n            for (;;) {\n                if ((t2h < rem) || ((t2h == rem) && (t2l <= n2)))\n                    break;\n                q--;\n                rem += d0;\n                if (rem < d0)\n                    break;\n                if (t2l < d1)\n                    t2h--;\n                t2l -= d1;\n            }\n#  endif\n        }\n# endif\n        l0 = bn_mul_words(tmp->d, sdiv->d, div_n, q);\n        tmp->d[div_n] = l0;\n        wnum--;\n        l0 = bn_sub_words(wnum, wnum, tmp->d, div_n + 1);\n        q -= l0;\n        for (l0 = 0 - l0, j = 0; j < div_n; j++)\n            tmp->d[j] = sdiv->d[j] & l0;\n        l0 = bn_add_words(wnum, wnum, tmp->d, div_n);\n        (*wnumtop) += l0;\n        assert((*wnumtop) == 0);\n        *--resp = q;\n    }\n    snum->neg = num->neg;\n    snum->top = div_n;\n    snum->flags |= BN_FLG_FIXED_TOP;\n    if (rm != NULL)\n        bn_rshift_fixed_top(rm, snum, norm_shift);\n    BN_CTX_end(ctx);\n    return 1;\n err:\n    bn_check_top(rm);\n    BN_CTX_end(ctx);\n    return 0;\n}', 'void BN_CTX_end(BN_CTX *ctx)\n{\n    CTXDBG("ENTER 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("LEAVE BN_CTX_end()", ctx);\n}', 'static unsigned int BN_STACK_pop(BN_STACK *st)\n{\n    return st->indexes[--(st->depth)];\n}']