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author | Dwayne C. Litzenberger <dlitz@dlitz.net> | 2011-02-21 20:00:37 -0500 |
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committer | Dwayne C. Litzenberger <dlitz@dlitz.net> | 2011-02-21 20:00:37 -0500 |
commit | 80252248ab1ac8599b946e026dd8895146977903 (patch) | |
tree | 7706be103e8001ecd3fc970b3f8fbbabdc790e76 /src/_fastmath.c | |
parent | abd276c5fa31abf0b1d70ca4624e30cdacaee867 (diff) | |
download | pycrypto-80252248ab1ac8599b946e026dd8895146977903.tar.gz |
Replace calls to mpz_powm with mpz_powm_sec. This should help avoid some timing attacks.
Thanks to Geremy Condra for pointing this out.
Diffstat (limited to 'src/_fastmath.c')
-rwxr-xr-x | src/_fastmath.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/src/_fastmath.c b/src/_fastmath.c index 67c3cc5..acfaed0 100755 --- a/src/_fastmath.c +++ b/src/_fastmath.c @@ -134,7 +134,7 @@ dsaSign (dsaKey * key, mpz_t m, mpz_t k, mpz_t r, mpz_t s) return 1; } mpz_init (temp); - mpz_powm (r, key->g, k, key->p); + mpz_powm_sec (r, key->g, k, key->p); mpz_mod (r, r, key->q); mpz_invert (s, k, key->q); mpz_mul (temp, key->x, r); @@ -163,8 +163,8 @@ dsaVerify (dsaKey * key, mpz_t m, mpz_t r, mpz_t s) mpz_mod (u1, u1, key->q); mpz_mul (u2, r, w); mpz_mod (u2, u2, key->q); - mpz_powm (v1, key->g, u1, key->p); - mpz_powm (v2, key->y, u2, key->p); + mpz_powm_sec (v1, key->g, u1, key->p); + mpz_powm_sec (v2, key->y, u2, key->p); mpz_mul (w, v1, v2); mpz_mod (w, w, key->p); mpz_mod (w, w, key->q); @@ -188,7 +188,7 @@ rsaEncrypt (rsaKey * key, mpz_t v) { return 1; } - mpz_powm (v, v, key->e, key->n); + mpz_powm_sec (v, v, key->e, key->n); return 0; } @@ -216,11 +216,11 @@ rsaDecrypt (rsaKey * key, mpz_t v) /* m1 = c ^ (d mod (p-1)) mod p */ mpz_sub_ui(h, key->p, 1); mpz_fdiv_r(h, key->d, h); - mpz_powm(m1, v, h, key->p); + mpz_powm_sec(m1, v, h, key->p); /* m2 = c ^ (d mod (q-1)) mod q */ mpz_sub_ui(h, key->q, 1); mpz_fdiv_r(h, key->d, h); - mpz_powm(m2, v, h, key->q); + mpz_powm_sec(m2, v, h, key->q); /* h = u * ( m2 - m1 ) mod q */ mpz_sub(h, m2, m1); if (mpz_sgn(h)==-1) @@ -239,7 +239,7 @@ rsaDecrypt (rsaKey * key, mpz_t v) } /* slow */ - mpz_powm (v, v, key->d, key->n); + mpz_powm_sec (v, v, key->d, key->n); return 0; } @@ -254,7 +254,7 @@ rsaBlind (rsaKey * key, mpz_t v, mpz_t b) { return 2; } - mpz_powm (b, b, key->e, key->n); + mpz_powm_sec (b, b, key->e, key->n); mpz_mul (v, v, b); mpz_mod (v, v, key->n); return 0; @@ -1101,7 +1101,7 @@ rabinMillerTest (mpz_t n, int rounds, PyObject *randfunc) } } while (base_was_tested); mpz_init_set (tested[i], a); - mpz_powm (z, a, m, n); + mpz_powm_sec (z, a, m, n); if ((mpz_cmp_ui (z, 1) == 0) || (mpz_cmp (z, n_1) == 0)) continue; composite = 1; |