/* crypto/bn/bn_exp.c */
-/* Copyright (C) 1995-1997 Eric Young (eay@cryptsoft.com)
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
#include "cryptlib.h"
#include "bn_lcl.h"
+#define TABLE_SIZE 16
+
/* slow but works */
-int BN_mod_mul(ret, a, b, m, ctx)
-BIGNUM *ret;
-BIGNUM *a;
-BIGNUM *b;
-BIGNUM *m;
-BN_CTX *ctx;
+int BN_mod_mul(BIGNUM *ret, BIGNUM *a, BIGNUM *b, BIGNUM *m, BN_CTX *ctx)
{
BIGNUM *t;
int r=0;
- t=ctx->bn[ctx->tos++];
+ bn_check_top(a);
+ bn_check_top(b);
+ bn_check_top(m);
+
+ t= &(ctx->bn[ctx->tos++]);
if (a == b)
{ if (!BN_sqr(t,a,ctx)) goto err; }
else
- { if (!BN_mul(t,a,b)) goto err; }
+ { if (!BN_mul(t,a,b,ctx)) goto err; }
if (!BN_mod(ret,t,m,ctx)) goto err;
r=1;
err:
#if 0
/* this one works - simple but works */
-int BN_mod_exp(r,a,p,m,ctx)
-BIGNUM *r,*a,*p,*m;
-BN_CTX *ctx;
+int BN_mod_exp(BIGNUM *r, BIGNUM *a, BIGNUM *p, BIGNUM *m, BN_CTX *ctx)
{
int i,bits,ret=0;
BIGNUM *v,*tmp;
- v=ctx->bn[ctx->tos++];
- tmp=ctx->bn[ctx->tos++];
+ v= &(ctx->bn[ctx->tos++]);
+ tmp= &(ctx->bn[ctx->tos++]);
if (BN_copy(v,a) == NULL) goto err;
bits=BN_num_bits(p);
if (BN_is_odd(p))
{ if (BN_copy(r,a) == NULL) goto err; }
- else { if (BN_one(r)) goto err; }
+ else { if (!BN_one(r)) goto err; }
for (i=1; i<bits; i++)
{
if (!BN_mod(v,tmp,m,ctx)) goto err;
if (BN_is_bit_set(p,i))
{
- if (!BN_mul(tmp,r,v)) goto err;
+ if (!BN_mul(tmp,r,v,ctx)) goto err;
if (!BN_mod(r,tmp,m,ctx)) goto err;
}
}
#endif
-int BN_mod_exp(r,a,p,m,ctx)
-BIGNUM *r;
-BIGNUM *a;
-BIGNUM *p;
-BIGNUM *m;
-BN_CTX *ctx;
+/* this one works - simple but works */
+int BN_exp(BIGNUM *r, BIGNUM *a, BIGNUM *p, BN_CTX *ctx)
+ {
+ int i,bits,ret=0,tos;
+ BIGNUM *v,*rr;
+
+ tos=ctx->tos;
+ v= &(ctx->bn[ctx->tos++]);
+ if ((r == a) || (r == p))
+ rr= &(ctx->bn[ctx->tos++]);
+ else
+ rr=r;
+
+ if (BN_copy(v,a) == NULL) goto err;
+ bits=BN_num_bits(p);
+
+ if (BN_is_odd(p))
+ { if (BN_copy(rr,a) == NULL) goto err; }
+ else { if (!BN_one(rr)) goto err; }
+
+ for (i=1; i<bits; i++)
+ {
+ if (!BN_sqr(v,v,ctx)) goto err;
+ if (BN_is_bit_set(p,i))
+ {
+ if (!BN_mul(rr,rr,v,ctx)) goto err;
+ }
+ }
+ ret=1;
+err:
+ ctx->tos=tos;
+ if (r != rr) BN_copy(r,rr);
+ return(ret);
+ }
+
+int BN_mod_exp(BIGNUM *r, BIGNUM *a, BIGNUM *p, BIGNUM *m, BN_CTX *ctx)
{
int ret;
+ bn_check_top(a);
+ bn_check_top(p);
+ bn_check_top(m);
+
#ifdef MONT_MUL_MOD
/* I have finally been able to take out this pre-condition of
* the top bit being set. It was caused by an error in BN_div
/* if ((m->d[m->top-1]&BN_TBIT) && BN_is_odd(m)) */
if (BN_is_odd(m))
- { ret=BN_mod_exp_mont(r,a,p,m,ctx); }
+ { ret=BN_mod_exp_mont(r,a,p,m,ctx,NULL); }
else
#endif
#ifdef RECP_MUL_MOD
}
/* #ifdef RECP_MUL_MOD */
-int BN_mod_exp_recp(r,a,p,m,ctx)
-BIGNUM *r;
-BIGNUM *a;
-BIGNUM *p;
-BIGNUM *m;
-BN_CTX *ctx;
+int BN_mod_exp_recp(BIGNUM *r, BIGNUM *a, BIGNUM *p, BIGNUM *m, BN_CTX *ctx)
{
- int nb,i,j,bits,ret=0,wstart,wend,window,wvalue;
- int start=1;
- BIGNUM *d,*aa;
- BIGNUM *val[16];
+ int i,j,bits,ret=0,wstart,wend,window,wvalue;
+ int start=1,ts=0;
+ BIGNUM *aa;
+ BIGNUM val[TABLE_SIZE];
+ BN_RECP_CTX recp;
- d=ctx->bn[ctx->tos++];
- aa=ctx->bn[ctx->tos++];
+ aa= &(ctx->bn[ctx->tos++]);
bits=BN_num_bits(p);
if (bits == 0)
BN_one(r);
return(1);
}
- nb=BN_reciprocal(d,m,ctx);
- if (nb == -1) goto err;
+ BN_RECP_CTX_init(&recp);
+ if (BN_RECP_CTX_set(&recp,m,ctx) <= 0) goto err;
- val[0]=BN_new();
- if (!BN_mod(val[0],a,m,ctx)) goto err; /* 1 */
- if (!BN_mod_mul_reciprocal(aa,val[0],val[0],m,d,nb,ctx))
+ BN_init(&(val[0]));
+ ts=1;
+
+ if (!BN_mod(&(val[0]),a,m,ctx)) goto err; /* 1 */
+ if (!BN_mod_mul_reciprocal(aa,&(val[0]),&(val[0]),&recp,ctx))
goto err; /* 2 */
if (bits <= 17) /* This is probably 3 or 0x10001, so just do singles */
j=1<<(window-1);
for (i=1; i<j; i++)
{
- val[i]=BN_new();
- if (!BN_mod_mul_reciprocal(val[i],val[i-1],aa,m,d,nb,ctx))
+ BN_init(&val[i]);
+ if (!BN_mod_mul_reciprocal(&(val[i]),&(val[i-1]),aa,&recp,ctx))
goto err;
}
- for (; i<16; i++)
- val[i]=NULL;
+ ts=i;
start=1; /* This is used to avoid multiplication etc
* when there is only the value '1' in the
if (BN_is_bit_set(p,wstart) == 0)
{
if (!start)
- if (!BN_mod_mul_reciprocal(r,r,r,m,d,nb,ctx))
+ if (!BN_mod_mul_reciprocal(r,r,r,&recp,ctx))
goto err;
if (wstart == 0) break;
wstart--;
if (!start)
for (i=0; i<j; i++)
{
- if (!BN_mod_mul_reciprocal(r,r,r,m,d,nb,ctx))
+ if (!BN_mod_mul_reciprocal(r,r,r,&recp,ctx))
goto err;
}
/* wvalue will be an odd number < 2^window */
- if (!BN_mod_mul_reciprocal(r,r,val[wvalue>>1],m,d,nb,ctx))
+ if (!BN_mod_mul_reciprocal(r,r,&(val[wvalue>>1]),&recp,ctx))
goto err;
/* move the 'window' down further */
}
ret=1;
err:
- ctx->tos-=2;
- for (i=0; i<16; i++)
- if (val[i] != NULL) BN_clear_free(val[i]);
+ ctx->tos--;
+ for (i=0; i<ts; i++)
+ BN_clear_free(&(val[i]));
+ BN_RECP_CTX_free(&recp);
return(ret);
}
/* #endif */
/* #ifdef MONT_MUL_MOD */
-int BN_mod_exp_mont(r,a,p,m,ctx)
-BIGNUM *r;
-BIGNUM *a;
-BIGNUM *p;
-BIGNUM *m;
-BN_CTX *ctx;
+int BN_mod_exp_mont(BIGNUM *rr, BIGNUM *a, BIGNUM *p, BIGNUM *m, BN_CTX *ctx,
+ BN_MONT_CTX *in_mont)
{
int i,j,bits,ret=0,wstart,wend,window,wvalue;
- int start=1;
- BIGNUM *d,*aa;
- BIGNUM *val[16];
+ int start=1,ts=0;
+ BIGNUM *d,*aa,*r;
+ BIGNUM val[TABLE_SIZE];
BN_MONT_CTX *mont=NULL;
+ bn_check_top(a);
+ bn_check_top(p);
+ bn_check_top(m);
+
if (!(m->d[0] & 1))
{
BNerr(BN_F_BN_MOD_EXP_MONT,BN_R_CALLED_WITH_EVEN_MODULUS);
return(0);
}
- d=ctx->bn[ctx->tos++];
+ d= &(ctx->bn[ctx->tos++]);
+ r= &(ctx->bn[ctx->tos++]);
bits=BN_num_bits(p);
if (bits == 0)
{
/* If this is not done, things will break in the montgomery
* part */
- if ((mont=BN_MONT_CTX_new()) == NULL) goto err;
- if (!BN_MONT_CTX_set(mont,m,ctx)) goto err;
+#if 1
+ if (in_mont != NULL)
+ mont=in_mont;
+ else
+#endif
+ {
+ if ((mont=BN_MONT_CTX_new()) == NULL) goto err;
+ if (!BN_MONT_CTX_set(mont,m,ctx)) goto err;
+ }
- val[0]=BN_new();
+ BN_init(&val[0]);
+ ts=1;
if (BN_ucmp(a,m) >= 0)
{
- BN_mod(val[0],a,m,ctx);
- aa=val[0];
+ BN_mod(&(val[0]),a,m,ctx);
+ aa= &(val[0]);
}
else
aa=a;
- if (!BN_to_montgomery(val[0],aa,mont,ctx)) goto err; /* 1 */
- if (!BN_mod_mul_montgomery(d,val[0],val[0],mont,ctx)) goto err; /* 2 */
+ if (!BN_to_montgomery(&(val[0]),aa,mont,ctx)) goto err; /* 1 */
+ if (!BN_mod_mul_montgomery(d,&(val[0]),&(val[0]),mont,ctx)) goto err; /* 2 */
- if (bits <= 17) /* This is probably 3 or 0x10001, so just do singles */
+ if (bits <= 20) /* This is probably 3 or 0x10001, so just do singles */
window=1;
else if (bits >= 256)
window=5; /* max size of window */
j=1<<(window-1);
for (i=1; i<j; i++)
{
- val[i]=BN_new();
- if (!BN_mod_mul_montgomery(val[i],val[i-1],d,mont,ctx))
+ BN_init(&(val[i]));
+ if (!BN_mod_mul_montgomery(&(val[i]),&(val[i-1]),d,mont,ctx))
goto err;
}
- for (; i<16; i++)
- val[i]=NULL;
+ ts=i;
start=1; /* This is used to avoid multiplication etc
* when there is only the value '1' in the
if (BN_is_bit_set(p,wstart) == 0)
{
if (!start)
+ {
if (!BN_mod_mul_montgomery(r,r,r,mont,ctx))
goto err;
+ }
if (wstart == 0) break;
wstart--;
continue;
}
/* wvalue will be an odd number < 2^window */
- if (!BN_mod_mul_montgomery(r,r,val[wvalue>>1],mont,ctx))
+ if (!BN_mod_mul_montgomery(r,r,&(val[wvalue>>1]),mont,ctx))
goto err;
/* move the 'window' down further */
start=0;
if (wstart < 0) break;
}
- BN_from_montgomery(r,r,mont,ctx);
+ BN_from_montgomery(rr,r,mont,ctx);
ret=1;
err:
- if (mont != NULL) BN_MONT_CTX_free(mont);
- ctx->tos--;
- for (i=0; i<16; i++)
- if (val[i] != NULL) BN_clear_free(val[i]);
+ if ((in_mont == NULL) && (mont != NULL)) BN_MONT_CTX_free(mont);
+ ctx->tos-=2;
+ for (i=0; i<ts; i++)
+ BN_clear_free(&(val[i]));
return(ret);
}
/* #endif */
/* The old fallback, simple version :-) */
-int BN_mod_exp_simple(r,a,p,m,ctx)
-BIGNUM *r;
-BIGNUM *a;
-BIGNUM *p;
-BIGNUM *m;
-BN_CTX *ctx;
+int BN_mod_exp_simple(BIGNUM *r, BIGNUM *a, BIGNUM *p, BIGNUM *m,
+ BN_CTX *ctx)
{
- int i,j,bits,ret=0,wstart,wend,window,wvalue;
+ int i,j,bits,ret=0,wstart,wend,window,wvalue,ts=0;
int start=1;
BIGNUM *d;
- BIGNUM *val[16];
+ BIGNUM val[TABLE_SIZE];
- d=ctx->bn[ctx->tos++];
+ d= &(ctx->bn[ctx->tos++]);
bits=BN_num_bits(p);
if (bits == 0)
return(1);
}
- val[0]=BN_new();
- if (!BN_mod(val[0],a,m,ctx)) goto err; /* 1 */
- if (!BN_mod_mul(d,val[0],val[0],m,ctx))
+ BN_init(&(val[0]));
+ ts=1;
+ if (!BN_mod(&(val[0]),a,m,ctx)) goto err; /* 1 */
+ if (!BN_mod_mul(d,&(val[0]),&(val[0]),m,ctx))
goto err; /* 2 */
if (bits <= 17) /* This is probably 3 or 0x10001, so just do singles */
j=1<<(window-1);
for (i=1; i<j; i++)
{
- val[i]=BN_new();
- if (!BN_mod_mul(val[i],val[i-1],d,m,ctx))
+ BN_init(&(val[i]));
+ if (!BN_mod_mul(&(val[i]),&(val[i-1]),d,m,ctx))
goto err;
}
- for (; i<16; i++)
- val[i]=NULL;
+ ts=i;
start=1; /* This is used to avoid multiplication etc
* when there is only the value '1' in the
}
/* wvalue will be an odd number < 2^window */
- if (!BN_mod_mul(r,r,val[wvalue>>1],m,ctx))
+ if (!BN_mod_mul(r,r,&(val[wvalue>>1]),m,ctx))
goto err;
/* move the 'window' down further */
ret=1;
err:
ctx->tos--;
- for (i=0; i<16; i++)
- if (val[i] != NULL) BN_clear_free(val[i]);
+ for (i=0; i<ts; i++)
+ BN_clear_free(&(val[i]));
return(ret);
}
projects / openssl.git / blobdiff