test/bntest.c:1432: error: BUFFER_OVERRUN_L3
  Offset added: [8, +oo] Size: [0, 536870848] by call to `BN_mod_exp`.
Showing all 18 steps of the trace


test/bntest.c:1424:23: Call
1422.       BIGNUM *e = getBN(s, "E");
1423.       BIGNUM *m = getBN(s, "M");
1424.       BIGNUM *mod_exp = getBN(s, "ModExp");
                              ^
1425.       BIGNUM *ret = BN_new();
1426.       BIGNUM *b = NULL, *c = NULL, *d = BN_new();

test/bntest.c:115:9: Call
  113.       }
  114.   
  115.       if (parseBN(&ret, hex) != (int)strlen(hex)) {
                 ^
  116.           fprintf(stderr, "Could not decode '%s'.\n", hex);
  117.           return NULL;

test/bntest.c:95:12: Call
    93.   {
    94.       *out = NULL;
    95.       return BN_hex2bn(out, in);
                     ^
    96.   }
    97.   

crypto/bn/bn_print.c:126:1: Parameter `(*bn)->top`
      124.   }
      125.   
      126. > int BN_hex2bn(BIGNUM **bn, const char *a)
      127.   {
      128.       BIGNUM *ret = NULL;

test/bntest.c:1432:10: Call
1430.           goto err;
1431.   
1432.       if (!BN_mod_exp(ret, a, e, m, ctx)
                 ^
1433.               || !equalBN("A ^ E (mod M)", mod_exp, ret))
1434.           goto err;

crypto/bn/bn_exp.c:91:1: Parameter `m->top`
  89.   }
  90.   
  91. > int BN_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, const BIGNUM *m,
  92.                  BN_CTX *ctx)
  93.   {

crypto/bn/bn_exp.c:136:9: Call
  134.   
  135.   #ifdef MONT_MUL_MOD
  136.       if (BN_is_odd(m)) {
                 ^
  137.   # ifdef MONT_EXP_WORD
  138.           if (a->top == 1 && !a->neg

crypto/bn/bn_lib.c:867:1: Parameter `a->top`
    865.   }
    866.   
    867. > int BN_is_odd(const BIGNUM *a)
    868.   {
    869.       return (a->top > 0) && (a->d[0] & 1);

crypto/bn/bn_exp.c:149:15: Call
  147.   #ifdef RECP_MUL_MOD
  148.       {
  149.           ret = BN_mod_exp_recp(r, a, p, m, ctx);
                       ^
  150.       }
  151.   #else

crypto/bn/bn_exp.c:161:1: Parameter `m->top`
    159.   }
    160.   
    161. > int BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
    162.                       const BIGNUM *m, BN_CTX *ctx)
    163.   {

crypto/bn/bn_exp.c:198:14: Call
    196.       if (m->neg) {
    197.           /* ignore sign of 'm' */
    198.           if (!BN_copy(aa, m))
                        ^
    199.               goto err;
    200.           aa->neg = 0;

crypto/bn/bn_lib.c:323:1: <Offset trace>
321.   }
322.   
323. > BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
324.   {
325.       bn_check_top(b);

crypto/bn/bn_lib.c:323:1: Parameter `b->top`
      321.   }
      322.   
      323. > BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
      324.   {
      325.       bn_check_top(b);

crypto/bn/bn_lib.c:323:1: <Length trace>
321.   }
322.   
323. > BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
324.   {
325.       bn_check_top(b);

crypto/bn/bn_lib.c:323:1: Parameter `*a->d`
      321.   }
      322.   
      323. > BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
      324.   {
      325.       bn_check_top(b);

crypto/bn/bn_lib.c:329:9: Call
      327.       if (a == b)
      328.           return a;
      329.       if (bn_wexpand(a, b->top) == NULL)
                     ^
      330.           return NULL;
      331.   

crypto/bn/bn_lib.c:948:1: Parameter `*a->d`
        946.   }
        947.   
        948. > BIGNUM *bn_wexpand(BIGNUM *a, int words)
        949.   {
        950.       return (words <= a->dmax) ? a : bn_expand2(a, words);

crypto/bn/bn_lib.c:333:9: Array access: Offset added: [8, +oo] Size: [0, 536870848] by call to `BN_mod_exp` 
      331.   
      332.       if (b->top > 0)
      333.           memcpy(a->d, b->d, sizeof(b->d[0]) * b->top);
                     ^
      334.   
      335.       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;
}
['static int file_modexp(STANZA *s)\n{\n    BIGNUM *a = getBN(s, "A");\n    BIGNUM *e = getBN(s, "E");\n    BIGNUM *m = getBN(s, "M");\n    BIGNUM *mod_exp = getBN(s, "ModExp");\n    BIGNUM *ret = BN_new();\n    BIGNUM *b = NULL, *c = NULL, *d = BN_new();\n    int st = 0;\n    if (a == NULL || e == NULL || m == NULL || mod_exp == NULL || ret == NULL)\n        goto err;\n    if (!BN_mod_exp(ret, a, e, m, ctx)\n            || !equalBN("A ^ E (mod M)", mod_exp, ret))\n        goto err;\n    if (BN_is_odd(m)) {\n        if (!BN_mod_exp_mont(ret, a, e, m, ctx, NULL)\n                || !equalBN("A ^ E (mod M) (mont)", mod_exp, ret)\n                || !BN_mod_exp_mont_consttime(ret, a, e, m, ctx, NULL)\n                || !equalBN("A ^ E (mod M) (mont const", mod_exp, ret))\n            goto err;\n    }\n    BN_hex2bn(&a, "050505050505");\n    BN_hex2bn(&b, "02");\n    BN_hex2bn(&c,\n        "4141414141414141414141274141414141414141414141414141414141414141"\n        "4141414141414141414141414141414141414141414141414141414141414141"\n        "4141414141414141414141800000000000000000000000000000000000000000"\n        "0000000000000000000000000000000000000000000000000000000000000000"\n        "0000000000000000000000000000000000000000000000000000000000000000"\n        "0000000000000000000000000000000000000000000000000000000001");\n    BN_mod_exp(d, a, b, c, ctx);\n    BN_mul(e, a, a, ctx);\n    if (BN_cmp(d, e)) {\n        fprintf(stderr, "BN_mod_exp and BN_mul produce different results!\\n");\n        goto err;\n    }\n    st = 1;\nerr:\n    BN_free(a);\n    BN_free(b);\n    BN_free(c);\n    BN_free(d);\n    BN_free(e);\n    BN_free(m);\n    BN_free(mod_exp);\n    BN_free(ret);\n    return st;\n}', 'static BIGNUM *getBN(STANZA *s, const char *attribute)\n{\n    const char *hex;\n    BIGNUM *ret = NULL;\n    if ((hex = findattr(s, attribute)) == NULL) {\n        fprintf(stderr, "Can\'t find %s in test at line %d\\n",\n                attribute, s->start);\n        return NULL;\n    }\n    if (parseBN(&ret, hex) != (int)strlen(hex)) {\n        fprintf(stderr, "Could not decode \'%s\'.\\n", hex);\n        return NULL;\n    }\n    return ret;\n}', 'static int parseBN(BIGNUM **out, const char *in)\n{\n    *out = NULL;\n    return BN_hex2bn(out, in);\n}', "int BN_hex2bn(BIGNUM **bn, const char *a)\n{\n    BIGNUM *ret = NULL;\n    BN_ULONG l = 0;\n    int neg = 0, h, m, i, j, k, c;\n    int num;\n    if ((a == NULL) || (*a == '\\0'))\n        return (0);\n    if (*a == '-') {\n        neg = 1;\n        a++;\n    }\n    for (i = 0; i <= (INT_MAX/4) && isxdigit((unsigned char)a[i]); i++)\n        continue;\n    if (i == 0 || i > INT_MAX/4)\n        goto err;\n    num = i + neg;\n    if (bn == NULL)\n        return (num);\n    if (*bn == NULL) {\n        if ((ret = BN_new()) == NULL)\n            return (0);\n    } else {\n        ret = *bn;\n        BN_zero(ret);\n    }\n    if (bn_expand(ret, i * 4) == NULL)\n        goto err;\n    j = i;\n    m = 0;\n    h = 0;\n    while (j > 0) {\n        m = ((BN_BYTES * 2) <= j) ? (BN_BYTES * 2) : j;\n        l = 0;\n        for (;;) {\n            c = a[j - m];\n            k = OPENSSL_hexchar2int(c);\n            if (k < 0)\n                k = 0;\n            l = (l << 4) | k;\n            if (--m <= 0) {\n                ret->d[h++] = l;\n                break;\n            }\n        }\n        j -= (BN_BYTES * 2);\n    }\n    ret->top = h;\n    bn_correct_top(ret);\n    *bn = ret;\n    bn_check_top(ret);\n    if (ret->top != 0)\n        ret->neg = neg;\n    return (num);\n err:\n    if (*bn == NULL)\n        BN_free(ret);\n    return (0);\n}", 'int BN_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, const BIGNUM *m,\n               BN_CTX *ctx)\n{\n    int ret;\n    bn_check_top(a);\n    bn_check_top(p);\n    bn_check_top(m);\n#define MONT_MUL_MOD\n#define MONT_EXP_WORD\n#define RECP_MUL_MOD\n#ifdef MONT_MUL_MOD\n    if (BN_is_odd(m)) {\n# ifdef MONT_EXP_WORD\n        if (a->top == 1 && !a->neg\n            && (BN_get_flags(p, BN_FLG_CONSTTIME) == 0)) {\n            BN_ULONG A = a->d[0];\n            ret = BN_mod_exp_mont_word(r, A, p, m, ctx, NULL);\n        } else\n# endif\n            ret = BN_mod_exp_mont(r, a, p, m, ctx, NULL);\n    } else\n#endif\n#ifdef RECP_MUL_MOD\n    {\n        ret = BN_mod_exp_recp(r, a, p, m, ctx);\n    }\n#else\n    {\n        ret = BN_mod_exp_simple(r, a, p, m, ctx);\n    }\n#endif\n    bn_check_top(r);\n    return (ret);\n}', 'int BN_is_odd(const BIGNUM *a)\n{\n    return (a->top > 0) && (a->d[0] & 1);\n}', 'int BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,\n                    const BIGNUM *m, BN_CTX *ctx)\n{\n    int i, j, bits, ret = 0, wstart, wend, window, wvalue;\n    int start = 1;\n    BIGNUM *aa;\n    BIGNUM *val[TABLE_SIZE];\n    BN_RECP_CTX recp;\n    if (BN_get_flags(p, BN_FLG_CONSTTIME) != 0) {\n        BNerr(BN_F_BN_MOD_EXP_RECP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);\n        return 0;\n    }\n    bits = BN_num_bits(p);\n    if (bits == 0) {\n        if (BN_is_one(m)) {\n            ret = 1;\n            BN_zero(r);\n        } else {\n            ret = BN_one(r);\n        }\n        return ret;\n    }\n    BN_CTX_start(ctx);\n    aa = BN_CTX_get(ctx);\n    val[0] = BN_CTX_get(ctx);\n    if (!aa || !val[0])\n        goto err;\n    BN_RECP_CTX_init(&recp);\n    if (m->neg) {\n        if (!BN_copy(aa, m))\n            goto err;\n        aa->neg = 0;\n        if (BN_RECP_CTX_set(&recp, aa, ctx) <= 0)\n            goto err;\n    } else {\n        if (BN_RECP_CTX_set(&recp, m, ctx) <= 0)\n            goto err;\n    }\n    if (!BN_nnmod(val[0], a, m, ctx))\n        goto err;\n    if (BN_is_zero(val[0])) {\n        BN_zero(r);\n        ret = 1;\n        goto err;\n    }\n    window = BN_window_bits_for_exponent_size(bits);\n    if (window > 1) {\n        if (!BN_mod_mul_reciprocal(aa, val[0], val[0], &recp, ctx))\n            goto err;\n        j = 1 << (window - 1);\n        for (i = 1; i < j; i++) {\n            if (((val[i] = BN_CTX_get(ctx)) == NULL) ||\n                !BN_mod_mul_reciprocal(val[i], val[i - 1], aa, &recp, ctx))\n                goto err;\n        }\n    }\n    start = 1;\n    wvalue = 0;\n    wstart = bits - 1;\n    wend = 0;\n    if (!BN_one(r))\n        goto err;\n    for (;;) {\n        if (BN_is_bit_set(p, wstart) == 0) {\n            if (!start)\n                if (!BN_mod_mul_reciprocal(r, r, r, &recp, ctx))\n                    goto err;\n            if (wstart == 0)\n                break;\n            wstart--;\n            continue;\n        }\n        j = wstart;\n        wvalue = 1;\n        wend = 0;\n        for (i = 1; i < window; i++) {\n            if (wstart - i < 0)\n                break;\n            if (BN_is_bit_set(p, wstart - i)) {\n                wvalue <<= (i - wend);\n                wvalue |= 1;\n                wend = i;\n            }\n        }\n        j = wend + 1;\n        if (!start)\n            for (i = 0; i < j; i++) {\n                if (!BN_mod_mul_reciprocal(r, r, r, &recp, ctx))\n                    goto err;\n            }\n        if (!BN_mod_mul_reciprocal(r, r, val[wvalue >> 1], &recp, ctx))\n            goto err;\n        wstart -= wend + 1;\n        wvalue = 0;\n        start = 0;\n        if (wstart < 0)\n            break;\n    }\n    ret = 1;\n err:\n    BN_CTX_end(ctx);\n    BN_RECP_CTX_free(&recp);\n    bn_check_top(r);\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}']