Changes between 0.9.6 and 0.9.7 [xx XXX 2000]
+ *) Make BN_mod_inverse faster by explicitly handling small quotients
+ in the Euclid loop instead of always using BN_div.
+ (Speed gain about 20% for small moduli [256 or 512 bits], about
+ 30% for larger ones [1024 or 2048 bits].)
+ [Bodo Moeller]
+
*) Disable ssl2_peek and ssl3_peek (i.e., both implementations
of SSL_peek) because they both are completely broken.
They will be fixed RSN by adding an additional 'peek' parameter
BN_init(&val[0]);
ts=1;
- if (!a->neg && BN_ucmp(a,m) >= 0)
+ if (a->neg || BN_ucmp(a,m) >= 0)
{
if (!BN_nnmod(&(val[0]),a,m,ctx))
goto err;
BIGNUM *BN_mod_inverse(BIGNUM *in,
const BIGNUM *a, const BIGNUM *n, BN_CTX *ctx)
{
- BIGNUM *A,*B,*X,*Y,*M,*D,*R=NULL;
+ BIGNUM *A,*B,*X,*Y,*M,*D,*T,*R=NULL;
BIGNUM *ret=NULL;
int sign;
D = BN_CTX_get(ctx);
M = BN_CTX_get(ctx);
Y = BN_CTX_get(ctx);
- if (Y == NULL) goto err;
+ T = BN_CTX_get(ctx);
+ if (T == NULL) goto err;
if (in == NULL)
R=BN_new();
* -sign*Y*a == A (mod |n|)
*/
- if (!BN_div(D,M,A,B,ctx)) goto err;
+ /* (D, M) := (A/B, A%B) ... */
+ if (BN_num_bits(A) == BN_num_bits(B))
+ {
+ if (!BN_one(D)) goto err;
+ if (!BN_sub(M,A,B)) goto err;
+ }
+ else if (BN_num_bits(A) == BN_num_bits(B) + 1)
+ {
+ /* A/B is 1, 2, or 3 */
+ if (!BN_lshift1(T,B)) goto err;
+ if (BN_ucmp(A,T) < 0)
+ {
+ /* A < 2*B, so D=1 */
+ if (!BN_one(D)) goto err;
+ if (!BN_sub(M,A,B)) goto err;
+ }
+ else
+ {
+ /* A >= 2*B, so D=2 or D=3 */
+ if (!BN_sub(M,A,T)) goto err;
+ if (!BN_add(D,T,B)) goto err; /* use D (:= 3*B) as temp */
+ if (BN_ucmp(A,D) < 0)
+ {
+ /* A < 3*B, so D=2 */
+ if (!BN_set_word(D,2)) goto err;
+ /* M (= A - 2*B) already has the correct value */
+ }
+ else
+ {
+ /* only D=3 remains */
+ if (!BN_set_word(D,3)) goto err;
+ /* currently M = A - 2*B, but we need M = A - 3*B */
+ if (!BN_sub(M,M,B)) goto err;
+ }
+ }
+ }
+ else
+ {
+ if (!BN_div(D,M,A,B,ctx)) goto err;
+ }
+
/* Now
* A = D*B + M;
* thus we have
* Note that X and Y stay non-negative all the time.
*/
- if (!BN_mul(tmp,D,X,ctx)) goto err;
- if (!BN_add(tmp,tmp,Y)) goto err;
+ /* most of the time D is very small, so we can optimize tmp := D*X+Y */
+ if (BN_is_one(D))
+ {
+ if (!BN_add(tmp,X,Y)) goto err;
+ }
+ else
+ {
+ if (BN_is_word(D,2))
+ {
+ if (!BN_lshift1(tmp,X)) goto err;
+ }
+ else if (BN_is_word(D,3))
+ {
+ if (!BN_lshift1(tmp,X)) goto err;
+ if (!BN_add(tmp,tmp,X)) goto err;
+ }
+ else if (BN_is_word(D,4))
+ {
+ if (!BN_lshift(tmp,X,2)) goto err;
+ }
+ else
+ {
+ if (!BN_mul(tmp,D,X,ctx)) goto err;
+ }
+ if (!BN_add(tmp,tmp,Y)) goto err;
+ }
+
M=Y; /* keep the BIGNUM object, the value does not matter */
Y=X;
X=tmp;
if (BN_is_one(A))
{
/* Y*a == 1 (mod |n|) */
- if (!BN_mod(R,Y,n,ctx)) goto err;
+ if (BN_ucmp(Y,n) < 0)
+ if (!BN_copy(R,Y)) goto err;
+ else
+ if (!BN_nnmod(R,Y,n,ctx)) goto err;
}
else
{
/* most of this code has been pilfered from my libdes speed.c program */
-#define BASENUM 5000
+#define BASENUM 10000
+#define NUM_START 0
+
+
+/* determine timings for modexp, gcd, or modular inverse */
+#define TEST_EXP
+#undef TEST_GCD
+#undef TEST_INV
+
+
#undef PROG
#define PROG bnspeed_main
#endif
}
-#define NUM_SIZES 6
-static int sizes[NUM_SIZES]={256,512,1024,2048,4096,8192};
-static int mul_c[NUM_SIZES]={8*8*8*8*8,8*8*8*8,8*8*8,8*8,8,1};
+#define NUM_SIZES 7
+#if NUM_START > NUM_SIZES
+# error "NUM_START > NUM_SIZES"
+#endif
+static int sizes[NUM_SIZES]={128,256,512,1024,2048,4096,8192};
+static int mul_c[NUM_SIZES]={8*8*8*8*8*8,8*8*8*8*8,8*8*8*8,8*8*8,8*8,8,1};
/*static int sizes[NUM_SIZES]={59,179,299,419,539}; */
+#define RAND_SEED(string) { const char str[] = string; RAND_seed(string, sizeof string); }
+
+static void genprime_cb(int p, int n, void *arg)
+ {
+ char c='*';
+
+ if (p == 0) c='.';
+ if (p == 1) c='+';
+ if (p == 2) c='*';
+ if (p == 3) c='\n';
+ putc(c, stderr);
+ fflush(stderr);
+ (void)n;
+ (void)arg;
+ }
+
void do_mul_exp(BIGNUM *r,BIGNUM *a,BIGNUM *b,BIGNUM *c,BN_CTX *ctx);
int main(int argc, char **argv)
c=BN_new();
r=BN_new();
+ while (!RAND_status())
+ /* not enough bits */
+ RAND_SEED("I demand a manual recount!");
+
do_mul_exp(r,a,b,c,ctx);
}
double tm;
long num;
+#if defined(TEST_EXP) + defined(TEST_GCD) + defined(TEST_INV) != 1
+# error "choose one test"
+#endif
+
+#ifdef TEST_INV
+# define C_PRIME
+#endif
+
num=BASENUM;
- for (i=0; i<NUM_SIZES; i++)
+ for (i=NUM_START; i<NUM_SIZES; i++)
{
- BN_pseudo_rand(a,sizes[i],1,0);
- BN_pseudo_rand(b,sizes[i],1,0);
- BN_pseudo_rand(c,sizes[i],1,1);
- BN_mod(a,a,c,ctx);
- BN_mod(b,b,c,ctx);
+#ifdef C_PRIME
+ if (!BN_generate_prime(c,sizes[i],0,NULL,NULL,genprime_cb,NULL)) goto err;
+ putc('\n', stderr);
+ fflush(stderr);
+#endif
Time_F(START);
for (k=0; k<num; k++)
- BN_mod_exp(r,a,b,c,ctx);
+ {
+ if (k%50 == 0) /* Average over num/50 different choices of random numbers. */
+ {
+ if (!BN_pseudo_rand(a,sizes[i],1,0)) goto err;
+ if (!BN_pseudo_rand(b,sizes[i],1,0)) goto err;
+#ifndef C_PRIME
+ if (!BN_pseudo_rand(c,sizes[i],1,1)) goto err;
+#endif
+ }
+#if defined(TEST_EXP)
+ if (!BN_mod_exp(r,a,b,c,ctx)) goto err;
+#elif defined(TEST_GCD)
+ if (!BN_gcd(r,a,b,ctx)) goto err;
+ if (!BN_gcd(r,b,c,ctx)) goto err;
+ if (!BN_gcd(r,b,c,ctx)) goto err;
+#else /* TEST_INV */
+ if (!BN_mod_inverse(r,a,c,ctx)) goto err;
+ if (!BN_mod_inverse(r,b,c,ctx)) goto err;
+#endif
+ }
tm=Time_F(STOP);
- printf("mul %4d ^ %4d %% %d -> %8.3fms %5.1f\n",sizes[i],sizes[i],sizes[i],tm*1000.0/num,tm*mul_c[i]/num);
+ printf(
+#if defined(TEST_EXP)
+ "modexp %4d ^ %4d %% %4d"
+#elif defined(TEST_GCD)
+ "3*gcd %4d %4d %4d"
+#else /* TEST_INV */
+ "2*inv %4d %4d mod %4d"
+#endif
+ " -> %8.3fms %5.1f (%d)\n",sizes[i],sizes[i],sizes[i],tm*1000.0/num,tm*mul_c[i]/num, num);
num/=7;
if (num <= 0) num=1;
}
+ return;
+ err:
+ ERR_print_errors_fp(stderr);
}
projects / openssl.git / commitdiff