crypto/bn/bn_mont.c:175: error: BUFFER_OVERRUN_S2
  Offset: [max(1, `mont->N.top`), +oo] (⇐ [0, +oo] + [max(1, `mont->N.top`), `mont->N.top`]) Size: [0, 8388607] by call to `BN_from_montgomery_word`.
Showing all 10 steps of the trace


crypto/bn/bn_mont.c:166:1: Parameter `mont->N.top`
164.   #endif                          /* MONT_WORD */
165.   
166. > int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont,
167.                          BN_CTX *ctx)
168.   {

crypto/bn/bn_mont.c:175:16: Call
173.       BN_CTX_start(ctx);
174.       if ((t = BN_CTX_get(ctx)) && BN_copy(t, a))
175.           retn = BN_from_montgomery_word(ret, t, mont);
                      ^
176.       BN_CTX_end(ctx);
177.   #else                           /* !MONT_WORD */

crypto/bn/bn_mont.c:104:21: <Offset trace>
102.       n0 = mont->n0[0];
103.   
104.       for (carry = 0, i = 0; i < nl; i++, rp++) {
                           ^
105.           v = bn_mul_add_words(rp, np, nl, (rp[0] * n0) & BN_MASK2);
106.           v = (v + carry + rp[nl]) & BN_MASK2;

crypto/bn/bn_mont.c:104:21: Assignment
  102.       n0 = mont->n0[0];
  103.   
  104.       for (carry = 0, i = 0; i < nl; i++, rp++) {
                             ^
  105.           v = bn_mul_add_words(rp, np, nl, (rp[0] * n0) & BN_MASK2);
  106.           v = (v + carry + rp[nl]) & BN_MASK2;

crypto/bn/bn_mont.c:75:1: <Length trace>
73.   
74.   #ifdef MONT_WORD
75. > static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont)
76.   {
77.       BIGNUM *n;

crypto/bn/bn_mont.c:75:1: Parameter `*r->d`
  73.   
  74.   #ifdef MONT_WORD
  75. > static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont)
  76.   {
  77.       BIGNUM *n;

crypto/bn/bn_mont.c:89:9: Call
  87.   
  88.       max = (2 * nl);             /* carry is stored separately */
  89.       if (bn_wexpand(r, max) == NULL)
                ^
  90.           return 0;
  91.   

crypto/bn/bn_lib.c:940:1: Parameter `*a->d`
    938.   }
    939.   
    940. > BIGNUM *bn_wexpand(BIGNUM *a, int words)
    941.   {
    942.       return (words <= a->dmax) ? a : bn_expand2(a, words);

crypto/bn/bn_mont.c:94:5: Assignment
  92.       r->neg ^= n->neg;
  93.       np = n->d;
  94.       rp = r->d;
            ^
  95.   
  96.       /* clear the top words of T */

crypto/bn/bn_mont.c:106:26: Array access: Offset: [max(1, mont->N.top), +oo] (⇐ [0, +oo] + [max(1, mont->N.top), mont->N.top]) Size: [0, 8388607] by call to `BN_from_montgomery_word` 
  104.       for (carry = 0, i = 0; i < nl; i++, rp++) {
  105.           v = bn_mul_add_words(rp, np, nl, (rp[0] * n0) & BN_MASK2);
  106.           v = (v + carry + rp[nl]) & BN_MASK2;
                                  ^
  107.           carry |= (v != rp[nl]);
  108.           carry &= (v <= rp[nl]);

static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont)
{
    BIGNUM *n;
    BN_ULONG *ap, *np, *rp, n0, v, carry;
    int nl, max, i;
    n = &(mont->N);
    nl = n->top;
    if (nl == 0) {
        ret->top = 0;
        return 1;
    }
    max = (2 * nl);
    if (bn_wexpand(r, max) == NULL)
        return 0;
    r->neg ^= n->neg;
    np = n->d;
    rp = r->d;
    i = max - r->top;
    if (i)
        memset(&rp[r->top], 0, sizeof(*rp) * i);
    r->top = max;
    n0 = mont->n0[0];
    for (carry = 0, i = 0; i < nl; i++, rp++) {
        v = bn_mul_add_words(rp, np, nl, (rp[0] * n0) & BN_MASK2);
        v = (v + carry + rp[nl]) & BN_MASK2;
        carry |= (v != rp[nl]);
        carry &= (v <= rp[nl]);
        rp[nl] = v;
    }
    if (bn_wexpand(ret, nl) == NULL)
        return 0;
    ret->top = nl;
    ret->neg = r->neg;
    rp = ret->d;
    ap = &(r->d[nl]);
# define BRANCH_FREE 1
# if BRANCH_FREE
    {
        BN_ULONG *nrp;
        size_t m;
        v = bn_sub_words(rp, ap, np, nl) - carry;
        m = (0 - (size_t)v);
        nrp =
            (BN_ULONG *)(((PTR_SIZE_INT) rp & ~m) | ((PTR_SIZE_INT) ap & m));
        for (i = 0, nl -= 4; i < nl; i += 4) {
            BN_ULONG t1, t2, t3, t4;
            t1 = nrp[i + 0];
            t2 = nrp[i + 1];
            t3 = nrp[i + 2];
            ap[i + 0] = 0;
            t4 = nrp[i + 3];
            ap[i + 1] = 0;
            rp[i + 0] = t1;
            ap[i + 2] = 0;
            rp[i + 1] = t2;
            ap[i + 3] = 0;
            rp[i + 2] = t3;
            rp[i + 3] = t4;
        }
        for (nl += 4; i < nl; i++)
            rp[i] = nrp[i], ap[i] = 0;
    }
# else
    if (bn_sub_words(rp, ap, np, nl) - carry)
        memcpy(rp, ap, nl * sizeof(BN_ULONG));
# endif
    bn_correct_top(r);
    bn_correct_top(ret);
    bn_check_top(ret);
    return 1;
}
['int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont,\n                       BN_CTX *ctx)\n{\n    int retn = 0;\n#ifdef MONT_WORD\n    BIGNUM *t;\n    BN_CTX_start(ctx);\n    if ((t = BN_CTX_get(ctx)) && BN_copy(t, a))\n        retn = BN_from_montgomery_word(ret, t, mont);\n    BN_CTX_end(ctx);\n#else\n    BIGNUM *t1, *t2;\n    BN_CTX_start(ctx);\n    t1 = BN_CTX_get(ctx);\n    t2 = BN_CTX_get(ctx);\n    if (t2 == NULL)\n        goto err;\n    if (!BN_copy(t1, a))\n        goto err;\n    BN_mask_bits(t1, mont->ri);\n    if (!BN_mul(t2, t1, &mont->Ni, ctx))\n        goto err;\n    BN_mask_bits(t2, mont->ri);\n    if (!BN_mul(t1, t2, &mont->N, ctx))\n        goto err;\n    if (!BN_add(t2, a, t1))\n        goto err;\n    if (!BN_rshift(ret, t2, mont->ri))\n        goto err;\n    if (BN_ucmp(ret, &(mont->N)) >= 0) {\n        if (!BN_usub(ret, ret, &(mont->N)))\n            goto err;\n    }\n    retn = 1;\n    bn_check_top(ret);\n err:\n    BN_CTX_end(ctx);\n#endif\n    return retn;\n}', 'static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont)\n{\n    BIGNUM *n;\n    BN_ULONG *ap, *np, *rp, n0, v, carry;\n    int nl, max, i;\n    n = &(mont->N);\n    nl = n->top;\n    if (nl == 0) {\n        ret->top = 0;\n        return 1;\n    }\n    max = (2 * nl);\n    if (bn_wexpand(r, max) == NULL)\n        return 0;\n    r->neg ^= n->neg;\n    np = n->d;\n    rp = r->d;\n    i = max - r->top;\n    if (i)\n        memset(&rp[r->top], 0, sizeof(*rp) * i);\n    r->top = max;\n    n0 = mont->n0[0];\n    for (carry = 0, i = 0; i < nl; i++, rp++) {\n        v = bn_mul_add_words(rp, np, nl, (rp[0] * n0) & BN_MASK2);\n        v = (v + carry + rp[nl]) & BN_MASK2;\n        carry |= (v != rp[nl]);\n        carry &= (v <= rp[nl]);\n        rp[nl] = v;\n    }\n    if (bn_wexpand(ret, nl) == NULL)\n        return 0;\n    ret->top = nl;\n    ret->neg = r->neg;\n    rp = ret->d;\n    ap = &(r->d[nl]);\n# define BRANCH_FREE 1\n# if BRANCH_FREE\n    {\n        BN_ULONG *nrp;\n        size_t m;\n        v = bn_sub_words(rp, ap, np, nl) - carry;\n        m = (0 - (size_t)v);\n        nrp =\n            (BN_ULONG *)(((PTR_SIZE_INT) rp & ~m) | ((PTR_SIZE_INT) ap & m));\n        for (i = 0, nl -= 4; i < nl; i += 4) {\n            BN_ULONG t1, t2, t3, t4;\n            t1 = nrp[i + 0];\n            t2 = nrp[i + 1];\n            t3 = nrp[i + 2];\n            ap[i + 0] = 0;\n            t4 = nrp[i + 3];\n            ap[i + 1] = 0;\n            rp[i + 0] = t1;\n            ap[i + 2] = 0;\n            rp[i + 1] = t2;\n            ap[i + 3] = 0;\n            rp[i + 2] = t3;\n            rp[i + 3] = t4;\n        }\n        for (nl += 4; i < nl; i++)\n            rp[i] = nrp[i], ap[i] = 0;\n    }\n# else\n    if (bn_sub_words(rp, ap, np, nl) - carry)\n        memcpy(rp, ap, nl * sizeof(BN_ULONG));\n# endif\n    bn_correct_top(r);\n    bn_correct_top(ret);\n    bn_check_top(ret);\n    return 1;\n}', 'BIGNUM *bn_wexpand(BIGNUM *a, int words)\n{\n    return (words <= a->dmax) ? a : bn_expand2(a, words);\n}']