generic-library/openssl
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Handle special cases correctly in exponentation functions.

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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.
This commit is contained in:
Bodo Möller 2000-11-30 00:33:18 +00:00
parent 6b5d39e82d
commit 73c2522c7c
2 changed files with 29 additions and 22 deletions
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31
crypto/bn/bn_exp.c
View File

@ -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)

20
crypto/bn/bn_exp2.c
View File

@ -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)
{