diff options
| author | Bodo Möller <bodo@openssl.org> | 2000-11-30 00:33:18 +0000 |
|---|---|---|
| committer | Bodo Möller <bodo@openssl.org> | 2000-11-30 00:33:18 +0000 |
| commit | 73c2522c7ce821f2c837b58eec7780fb43aa7d4f (patch) | |
| tree | ba2134dd79ac3f63a164dc40a059627f9801a6b2 /crypto/bn/bn_exp2.c | |
| parent | 6b5d39e82d9919f204dae3acae3769e00df71b4d (diff) | |
Handle special cases correctly in exponentation functions.
test_bn still fails in the BN_sqrt test because
small primes appear to turn into zero for no
obvious reason, leading to "div by zero" errors.
Diffstat (limited to 'crypto/bn/bn_exp2.c')
| -rw-r--r-- | crypto/bn/bn_exp2.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/crypto/bn/bn_exp2.c b/crypto/bn/bn_exp2.c index 56f1c959bd..4b41dae078 100644 --- a/crypto/bn/bn_exp2.c +++ b/crypto/bn/bn_exp2.c @@ -144,11 +144,6 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1, ret = BN_one(rr); return ret; } - if (BN_is_zero(a1) || BN_is_zero(a2)) - { - ret = BN_zero(rr); - return ret; - } bits=(bits1 > bits2)?bits1:bits2; @@ -173,7 +168,7 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1, */ BN_init(&val1[0]); ts1=1; - if (BN_ucmp(a1,m) >= 0) + if (a1->neg || BN_ucmp(a1,m) >= 0) { if (!BN_mod(&(val1[0]),a1,m,ctx)) goto err; @@ -181,6 +176,12 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1, } else a_mod_m = a1; + if (BN_is_zero(&(val1[0]))) + { + ret = BN_zero(rr); + goto err; + } + if (!BN_to_montgomery(&(val1[0]),a_mod_m,mont,ctx)) goto err; if (window1 > 1) { @@ -202,7 +203,7 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1, */ BN_init(&val2[0]); ts2=1; - if (BN_ucmp(a2,m) >= 0) + if (a2->neg || BN_ucmp(a2,m) >= 0) { if (!BN_mod(&(val2[0]),a2,m,ctx)) goto err; @@ -210,6 +211,11 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1, } else a_mod_m = a2; + if (BN_is_zero(&(val2[0]))) + { + ret = BN_zero(rr); + goto err; + } if (!BN_to_montgomery(&(val2[0]),a_mod_m,mont,ctx)) goto err; if (window2 > 1) { |