* - Geoff
*/
+
+
#include <stdio.h>
#include <time.h>
#include "cryptlib.h"
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,*ctx2=NULL;
+ BN_CTX *ctx=NULL;
+
+ local_r0 = BN_new();
+ local_d = BN_new();
+ local_p = BN_new();
+ if(!local_r0 || !local_d || !local_p)
+ goto err;
ctx=BN_CTX_new();
if (ctx == NULL) goto err;
- ctx2=BN_CTX_new();
- if (ctx2 == NULL) goto err;
BN_CTX_start(ctx);
r0 = BN_CTX_get(ctx);
r1 = BN_CTX_get(ctx);
goto err;
for (;;)
{
- if(!BN_generate_prime_ex(rsa->q, bitsq, 0, NULL, NULL, cb))
+ /* When generating ridiculously small keys, we can get stuck
+ * continually regenerating the same prime values. Check for
+ * this and bail if it happens 3 times. */
+ unsigned int degenerate = 0;
+ do
+ {
+ if(!BN_generate_prime_ex(rsa->q, bitsq, 0, NULL, NULL, cb))
+ goto err;
+ } while((BN_cmp(rsa->p, rsa->q) == 0) && (++degenerate < 3));
+ if(degenerate == 3)
+ {
+ ok = 0; /* we set our own err */
+ RSAerr(RSA_F_RSA_BUILTIN_KEYGEN,RSA_R_KEY_SIZE_TOO_SMALL);
goto err;
+ }
if (!BN_sub(r2,rsa->q,BN_value_one())) goto err;
if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
- if (BN_is_one(r1) && (BN_cmp(rsa->p,rsa->q) != 0))
+ if (BN_is_one(r1))
break;
if(!BN_GENCB_call(cb, 2, n++))
goto err;
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) */
-
-/* should not be needed, since gcd(p-1,e) == 1 and gcd(q-1,e) == 1 */
-/* for (;;)
+ if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
{
- if (!BN_gcd(r3,r0,rsa->e,ctx)) goto err;
- if (BN_is_one(r3)) break;
+ 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 */
- if (1)
- {
- if (!BN_add_word(rsa->e,2L)) goto err;
- continue;
- }
- RSAerr(RSA_F_RSA_GENERATE_KEY,RSA_R_BAD_E_VALUE);
- goto err;
+ /* 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);
}
-*/
- if (!BN_mod_inverse(rsa->d,rsa->e,r0,ctx2)) goto err; /* d */
+ 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,ctx2)) 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:
+ if(local_r0) BN_free(local_r0);
+ if(local_d) BN_free(local_d);
+ if(local_p) BN_free(local_p);
if (ok == -1)
{
- RSAerr(RSA_F_RSA_GENERATE_KEY,ERR_LIB_BN);
+ RSAerr(RSA_F_RSA_BUILTIN_KEYGEN,ERR_LIB_BN);
ok=0;
}
- BN_CTX_end(ctx);
- BN_CTX_free(ctx);
- BN_CTX_free(ctx2);
+ if (ctx != NULL)
+ {
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ }
return ok;
}