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_exp.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_exp.c')
| -rw-r--r-- | crypto/bn/bn_exp.c | 31 |
1 files changed, 16 insertions, 15 deletions
diff --git a/crypto/bn/bn_exp.c b/crypto/bn/bn_exp.c index 51c8282593..f7e7ced2ca 100644 --- a/crypto/bn/bn_exp.c +++ b/crypto/bn/bn_exp.c @@ -240,11 +240,6 @@ int BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, ret = BN_one(r); return ret; } - if (BN_is_zero(a)) - { - ret = BN_zero(r); - return ret; - } BN_CTX_start(ctx); if ((aa = BN_CTX_get(ctx)) == NULL) goto err; @@ -256,6 +251,11 @@ int BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, ts=1; if (!BN_nnmod(&(val[0]),a,m,ctx)) goto err; /* 1 */ + if (BN_is_zero(&(val[0]))) + { + ret = BN_zero(r); + goto err; + } window = BN_window_bits_for_exponent_size(bits); if (window > 1) @@ -365,11 +365,7 @@ int BN_mod_exp_mont(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p, ret = BN_one(rr); return ret; } - if (BN_is_zero(a)) - { - ret = BN_zero(rr); - return ret; - } + BN_CTX_start(ctx); d = BN_CTX_get(ctx); r = BN_CTX_get(ctx); @@ -396,6 +392,11 @@ int BN_mod_exp_mont(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p, } else aa=a; + if (BN_is_zero(aa)) + { + ret = BN_zero(rr); + goto err; + } if (!BN_to_montgomery(&(val[0]),aa,mont,ctx)) goto err; /* 1 */ window = BN_window_bits_for_exponent_size(bits); @@ -632,11 +633,6 @@ int BN_mod_exp_simple(BIGNUM *r, ret = BN_one(r); return ret; } - if (BN_is_zero(a)) - { - ret = BN_one(r); - return ret; - } BN_CTX_start(ctx); if ((d = BN_CTX_get(ctx)) == NULL) goto err; @@ -644,6 +640,11 @@ int BN_mod_exp_simple(BIGNUM *r, BN_init(&(val[0])); ts=1; if (!BN_nnmod(&(val[0]),a,m,ctx)) goto err; /* 1 */ + if (BN_is_zero(&(val[0]))) + { + ret = BN_one(r); + return ret; + } window = BN_window_bits_for_exponent_size(bits); if (window > 1) |