Change to mitigate branch prediction attacks

Submitted by: Matthew D Wood
Reviewed by: Bodo Moeller
This commit is contained in:
Bodo Möller
2007-03-28 00:15:28 +00:00
parent b506821d43
commit bd31fb2145
16 changed files with 595 additions and 42 deletions

View File

@@ -85,6 +85,8 @@ int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
{
BIGNUM *r0=NULL,*r1=NULL,*r2=NULL,*r3=NULL,*tmp;
BIGNUM local_r0,local_d,local_p;
BIGNUM *pr0,*d,*p;
int bitsp,bitsq,ok= -1,n=0;
BN_CTX *ctx=NULL;
@@ -165,16 +167,39 @@ static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
if (!BN_sub(r1,rsa->p,BN_value_one())) goto err; /* p-1 */
if (!BN_sub(r2,rsa->q,BN_value_one())) goto err; /* q-1 */
if (!BN_mul(r0,r1,r2,ctx)) goto err; /* (p-1)(q-1) */
if (!BN_mod_inverse(rsa->d,rsa->e,r0,ctx)) goto err; /* d */
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
{
pr0 = &local_r0;
BN_with_flags(pr0, r0, BN_FLG_CONSTTIME);
}
else
pr0 = r0;
if (!BN_mod_inverse(rsa->d,rsa->e,pr0,ctx)) goto err; /* d */
/* set up d for correct BN_FLG_CONSTTIME flag */
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
{
d = &local_d;
BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
}
else
d = rsa->d;
/* calculate d mod (p-1) */
if (!BN_mod(rsa->dmp1,rsa->d,r1,ctx)) goto err;
if (!BN_mod(rsa->dmp1,d,r1,ctx)) goto err;
/* calculate d mod (q-1) */
if (!BN_mod(rsa->dmq1,rsa->d,r2,ctx)) goto err;
if (!BN_mod(rsa->dmq1,d,r2,ctx)) goto err;
/* calculate inverse of q mod p */
if (!BN_mod_inverse(rsa->iqmp,rsa->q,rsa->p,ctx)) goto err;
if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
{
p = &local_p;
BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
}
else
p = rsa->p;
if (!BN_mod_inverse(rsa->iqmp,rsa->q,p,ctx)) goto err;
ok=1;
err: