test/exptest.c:161: error: BUFFER_OVERRUN_L3
  Offset: [1, +oo] Size: [0, 8388607] by call to `BN_mod_exp_mont`.
Showing all 8 steps of the trace


test/exptest.c:159:10: Call
157.       BN_rand(m, NUM_BITS + c, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ODD);
158.   
159.       if (!TEST_true(BN_mod(a, a, m, ctx))
                ^
160.           || !TEST_true(BN_mod(b, b, m, ctx))
161.           || !TEST_true(BN_mod_exp_mont(r_mont, a, b, m, ctx, NULL))

crypto/bn/bn_div.c:209:1: Parameter `rm->top`
  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.   {

test/exptest.c:161:13: Call
159.       if (!TEST_true(BN_mod(a, a, m, ctx))
160.           || !TEST_true(BN_mod(b, b, m, ctx))
161.           || !TEST_true(BN_mod_exp_mont(r_mont, a, b, m, ctx, NULL))
                   ^
162.           || !TEST_true(BN_mod_exp_recp(r_recp, a, b, m, ctx))
163.           || !TEST_true(BN_mod_exp_simple(r_simple, a, b, m, ctx))

crypto/bn/bn_exp.c:388:14: <Offset trace>
386.           /* 2^(top*BN_BITS2) - m */
387.           r->d[0] = (0 - m->d[0]) & BN_MASK2;
388.           for (i = 1; i < j; i++)
                    ^
389.               r->d[i] = (~m->d[i]) & BN_MASK2;
390.           r->top = j;

crypto/bn/bn_exp.c:388:14: Assignment
  386.           /* 2^(top*BN_BITS2) - m */
  387.           r->d[0] = (0 - m->d[0]) & BN_MASK2;
  388.           for (i = 1; i < j; i++)
                      ^
  389.               r->d[i] = (~m->d[i]) & BN_MASK2;
  390.           r->top = j;

crypto/bn/bn_exp.c:296:1: <Length trace>
294.   }
295.   
296. > int BN_mod_exp_mont(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
297.                       const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
298.   {

crypto/bn/bn_exp.c:296:1: Parameter `*m->d`
  294.   }
  295.   
  296. > int BN_mod_exp_mont(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
  297.                       const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
  298.   {

crypto/bn/bn_exp.c:389:25: Array access: Offset: [1, +oo] Size: [0, 8388607] by call to `BN_mod_exp_mont` 
  387.           r->d[0] = (0 - m->d[0]) & BN_MASK2;
  388.           for (i = 1; i < j; i++)
  389.               r->d[i] = (~m->d[i]) & BN_MASK2;
                                 ^
  390.           r->top = j;
  391.           r->flags |= BN_FLG_FIXED_TOP;

int BN_mod_exp_mont(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
                    const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
{
    int i, j, bits, ret = 0, wstart, wend, window, wvalue;
    int start = 1;
    BIGNUM *d, *r;
    const BIGNUM *aa;
    BIGNUM *val[TABLE_SIZE];
    BN_MONT_CTX *mont = NULL;
    if (BN_get_flags(p, BN_FLG_CONSTTIME) != 0
            || BN_get_flags(a, BN_FLG_CONSTTIME) != 0
            || BN_get_flags(m, BN_FLG_CONSTTIME) != 0) {
        return BN_mod_exp_mont_consttime(rr, a, p, m, ctx, in_mont);
    }
    bn_check_top(a);
    bn_check_top(p);
    bn_check_top(m);
    if (!BN_is_odd(m)) {
        BNerr(BN_F_BN_MOD_EXP_MONT, BN_R_CALLED_WITH_EVEN_MODULUS);
        return 0;
    }
    bits = BN_num_bits(p);
    if (bits == 0) {
        if (BN_abs_is_word(m, 1)) {
            ret = 1;
            BN_zero(rr);
        } else {
            ret = BN_one(rr);
        }
        return ret;
    }
    BN_CTX_start(ctx);
    d = BN_CTX_get(ctx);
    r = BN_CTX_get(ctx);
    val[0] = BN_CTX_get(ctx);
    if (val[0] == NULL)
        goto err;
    if (in_mont != NULL)
        mont = in_mont;
    else {
        if ((mont = BN_MONT_CTX_new()) == NULL)
            goto err;
        if (!BN_MONT_CTX_set(mont, m, ctx))
            goto err;
    }
    if (a->neg || BN_ucmp(a, m) >= 0) {
        if (!BN_nnmod(val[0], a, m, ctx))
            goto err;
        aa = val[0];
    } else
        aa = a;
    if (!bn_to_mont_fixed_top(val[0], aa, mont, ctx))
        goto err;
    window = BN_window_bits_for_exponent_size(bits);
    if (window > 1) {
        if (!bn_mul_mont_fixed_top(d, val[0], val[0], mont, ctx))
            goto err;
        j = 1 << (window - 1);
        for (i = 1; i < j; i++) {
            if (((val[i] = BN_CTX_get(ctx)) == NULL) ||
                !bn_mul_mont_fixed_top(val[i], val[i - 1], d, mont, ctx))
                goto err;
        }
    }
    start = 1;
    wvalue = 0;
    wstart = bits - 1;
    wend = 0;
#if 1
    j = m->top;
    if (m->d[j - 1] & (((BN_ULONG)1) << (BN_BITS2 - 1))) {
        if (bn_wexpand(r, j) == NULL)
            goto err;
        r->d[0] = (0 - m->d[0]) & BN_MASK2;
        for (i = 1; i < j; i++)
            r->d[i] = (~m->d[i]) & BN_MASK2;
        r->top = j;
        r->flags |= BN_FLG_FIXED_TOP;
    } else
#endif
    if (!bn_to_mont_fixed_top(r, BN_value_one(), mont, ctx))
        goto err;
    for (;;) {
        if (BN_is_bit_set(p, wstart) == 0) {
            if (!start) {
                if (!bn_mul_mont_fixed_top(r, r, r, mont, ctx))
                    goto err;
            }
            if (wstart == 0)
                break;
            wstart--;
            continue;
        }
        j = wstart;
        wvalue = 1;
        wend = 0;
        for (i = 1; i < window; i++) {
            if (wstart - i < 0)
                break;
            if (BN_is_bit_set(p, wstart - i)) {
                wvalue <<= (i - wend);
                wvalue |= 1;
                wend = i;
            }
        }
        j = wend + 1;
        if (!start)
            for (i = 0; i < j; i++) {
                if (!bn_mul_mont_fixed_top(r, r, r, mont, ctx))
                    goto err;
            }
        if (!bn_mul_mont_fixed_top(r, r, val[wvalue >> 1], mont, ctx))
            goto err;
        wstart -= wend + 1;
        wvalue = 0;
        start = 0;
        if (wstart < 0)
            break;
    }
#if defined(SPARC_T4_MONT)
    if (OPENSSL_sparcv9cap_P[0] & (SPARCV9_VIS3 | SPARCV9_PREFER_FPU)) {
        j = mont->N.top;
        val[0]->d[0] = 1;
        for (i = 1; i < j; i++)
            val[0]->d[i] = 0;
        val[0]->top = j;
        if (!BN_mod_mul_montgomery(rr, r, val[0], mont, ctx))
            goto err;
    } else
#endif
    if (!BN_from_montgomery(rr, r, mont, ctx))
        goto err;
    ret = 1;
 err:
    if (in_mont == NULL)
        BN_MONT_CTX_free(mont);
    BN_CTX_end(ctx);
    bn_check_top(rr);
    return ret;
}
['static int test_mod_exp(int round)\n{\n    BN_CTX *ctx;\n    unsigned char c;\n    int ret = 0;\n    BIGNUM *r_mont = NULL;\n    BIGNUM *r_mont_const = NULL;\n    BIGNUM *r_recp = NULL;\n    BIGNUM *r_simple = NULL;\n    BIGNUM *a = NULL;\n    BIGNUM *b = NULL;\n    BIGNUM *m = NULL;\n    if (!TEST_ptr(ctx = BN_CTX_new()))\n        goto err;\n    if (!TEST_ptr(r_mont = BN_new())\n        || !TEST_ptr(r_mont_const = BN_new())\n        || !TEST_ptr(r_recp = BN_new())\n        || !TEST_ptr(r_simple = BN_new())\n        || !TEST_ptr(a = BN_new())\n        || !TEST_ptr(b = BN_new())\n        || !TEST_ptr(m = BN_new()))\n        goto err;\n    RAND_bytes(&c, 1);\n    c = (c % BN_BITS) - BN_BITS2;\n    BN_rand(a, NUM_BITS + c, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY);\n    RAND_bytes(&c, 1);\n    c = (c % BN_BITS) - BN_BITS2;\n    BN_rand(b, NUM_BITS + c, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY);\n    RAND_bytes(&c, 1);\n    c = (c % BN_BITS) - BN_BITS2;\n    BN_rand(m, NUM_BITS + c, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ODD);\n    if (!TEST_true(BN_mod(a, a, m, ctx))\n        || !TEST_true(BN_mod(b, b, m, ctx))\n        || !TEST_true(BN_mod_exp_mont(r_mont, a, b, m, ctx, NULL))\n        || !TEST_true(BN_mod_exp_recp(r_recp, a, b, m, ctx))\n        || !TEST_true(BN_mod_exp_simple(r_simple, a, b, m, ctx))\n        || !TEST_true(BN_mod_exp_mont_consttime(r_mont_const, a, b, m, ctx, NULL)))\n        goto err;\n    if (!TEST_BN_eq(r_simple, r_mont)\n        || !TEST_BN_eq(r_simple, r_recp)\n        || !TEST_BN_eq(r_simple, r_mont_const)) {\n        if (BN_cmp(r_simple, r_mont) != 0)\n            TEST_info("simple and mont results differ");\n        if (BN_cmp(r_simple, r_mont_const) != 0)\n            TEST_info("simple and mont const time results differ");\n        if (BN_cmp(r_simple, r_recp) != 0)\n            TEST_info("simple and recp results differ");\n        BN_print_var(a);\n        BN_print_var(b);\n        BN_print_var(m);\n        BN_print_var(r_simple);\n        BN_print_var(r_recp);\n        BN_print_var(r_mont);\n        BN_print_var(r_mont_const);\n        goto err;\n    }\n    ret = 1;\n err:\n    BN_free(r_mont);\n    BN_free(r_mont_const);\n    BN_free(r_recp);\n    BN_free(r_simple);\n    BN_free(a);\n    BN_free(b);\n    BN_free(m);\n    BN_CTX_free(ctx);\n    return ret;\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_mod_exp_mont(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,\n                    const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)\n{\n    int i, j, bits, ret = 0, wstart, wend, window, wvalue;\n    int start = 1;\n    BIGNUM *d, *r;\n    const BIGNUM *aa;\n    BIGNUM *val[TABLE_SIZE];\n    BN_MONT_CTX *mont = NULL;\n    if (BN_get_flags(p, BN_FLG_CONSTTIME) != 0\n            || BN_get_flags(a, BN_FLG_CONSTTIME) != 0\n            || BN_get_flags(m, BN_FLG_CONSTTIME) != 0) {\n        return BN_mod_exp_mont_consttime(rr, a, p, m, ctx, in_mont);\n    }\n    bn_check_top(a);\n    bn_check_top(p);\n    bn_check_top(m);\n    if (!BN_is_odd(m)) {\n        BNerr(BN_F_BN_MOD_EXP_MONT, BN_R_CALLED_WITH_EVEN_MODULUS);\n        return 0;\n    }\n    bits = BN_num_bits(p);\n    if (bits == 0) {\n        if (BN_abs_is_word(m, 1)) {\n            ret = 1;\n            BN_zero(rr);\n        } else {\n            ret = BN_one(rr);\n        }\n        return ret;\n    }\n    BN_CTX_start(ctx);\n    d = BN_CTX_get(ctx);\n    r = BN_CTX_get(ctx);\n    val[0] = BN_CTX_get(ctx);\n    if (val[0] == NULL)\n        goto err;\n    if (in_mont != NULL)\n        mont = in_mont;\n    else {\n        if ((mont = BN_MONT_CTX_new()) == NULL)\n            goto err;\n        if (!BN_MONT_CTX_set(mont, m, ctx))\n            goto err;\n    }\n    if (a->neg || BN_ucmp(a, m) >= 0) {\n        if (!BN_nnmod(val[0], a, m, ctx))\n            goto err;\n        aa = val[0];\n    } else\n        aa = a;\n    if (!bn_to_mont_fixed_top(val[0], aa, mont, ctx))\n        goto err;\n    window = BN_window_bits_for_exponent_size(bits);\n    if (window > 1) {\n        if (!bn_mul_mont_fixed_top(d, val[0], val[0], mont, 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_mul_mont_fixed_top(val[i], val[i - 1], d, mont, ctx))\n                goto err;\n        }\n    }\n    start = 1;\n    wvalue = 0;\n    wstart = bits - 1;\n    wend = 0;\n#if 1\n    j = m->top;\n    if (m->d[j - 1] & (((BN_ULONG)1) << (BN_BITS2 - 1))) {\n        if (bn_wexpand(r, j) == NULL)\n            goto err;\n        r->d[0] = (0 - m->d[0]) & BN_MASK2;\n        for (i = 1; i < j; i++)\n            r->d[i] = (~m->d[i]) & BN_MASK2;\n        r->top = j;\n        r->flags |= BN_FLG_FIXED_TOP;\n    } else\n#endif\n    if (!bn_to_mont_fixed_top(r, BN_value_one(), mont, ctx))\n        goto err;\n    for (;;) {\n        if (BN_is_bit_set(p, wstart) == 0) {\n            if (!start) {\n                if (!bn_mul_mont_fixed_top(r, r, r, mont, ctx))\n                    goto err;\n            }\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_mul_mont_fixed_top(r, r, r, mont, ctx))\n                    goto err;\n            }\n        if (!bn_mul_mont_fixed_top(r, r, val[wvalue >> 1], mont, ctx))\n            goto err;\n        wstart -= wend + 1;\n        wvalue = 0;\n        start = 0;\n        if (wstart < 0)\n            break;\n    }\n#if defined(SPARC_T4_MONT)\n    if (OPENSSL_sparcv9cap_P[0] & (SPARCV9_VIS3 | SPARCV9_PREFER_FPU)) {\n        j = mont->N.top;\n        val[0]->d[0] = 1;\n        for (i = 1; i < j; i++)\n            val[0]->d[i] = 0;\n        val[0]->top = j;\n        if (!BN_mod_mul_montgomery(rr, r, val[0], mont, ctx))\n            goto err;\n    } else\n#endif\n    if (!BN_from_montgomery(rr, r, mont, ctx))\n        goto err;\n    ret = 1;\n err:\n    if (in_mont == NULL)\n        BN_MONT_CTX_free(mont);\n    BN_CTX_end(ctx);\n    bn_check_top(rr);\n    return ret;\n}']