提交 6dad7bd6 编写于 作者: B Bodo Möller

Speed up DH with small generator.

上级 208f3688
......@@ -4,6 +4,11 @@
Changes between 0.9.5a and 0.9.6 [xx XXX 2000]
*) New function BN_mod_exp_mont_word for small bases (roughly 20%
faster than BN_mod_exp_mont even though it does not use
windowing).
[Bodo Moeller]
*) CygWin32 support.
[John Jarvie <jjarvie@newsguy.com>]
......
......@@ -364,6 +364,8 @@ int BN_mod_exp(BIGNUM *r, BIGNUM *a, const BIGNUM *p,
const BIGNUM *m,BN_CTX *ctx);
int BN_mod_exp_mont(BIGNUM *r, BIGNUM *a, const BIGNUM *p,
const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
int BN_mod_exp_mont_word(BIGNUM *r, BN_ULONG a, const BIGNUM *p,
const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
int BN_mod_exp2_mont(BIGNUM *r, BIGNUM *a1, BIGNUM *p1,BIGNUM *a2,
BIGNUM *p2,BIGNUM *m,BN_CTX *ctx,BN_MONT_CTX *m_ctx);
int BN_mod_exp_simple(BIGNUM *r, BIGNUM *a, BIGNUM *p,
......@@ -484,6 +486,7 @@ BN_ULONG bn_sub_words(BN_ULONG *rp, BN_ULONG *ap, BN_ULONG *bp,int num);
#define BN_F_BN_DIV 107
#define BN_F_BN_EXPAND2 108
#define BN_F_BN_MOD_EXP_MONT 109
#define BN_F_BN_MOD_EXP_MONT_WORD 117
#define BN_F_BN_MOD_INVERSE 110
#define BN_F_BN_MOD_MUL_RECIPROCAL 111
#define BN_F_BN_MPI2BN 112
......
......@@ -77,6 +77,7 @@ static ERR_STRING_DATA BN_str_functs[]=
{ERR_PACK(0,BN_F_BN_DIV,0), "BN_div"},
{ERR_PACK(0,BN_F_BN_EXPAND2,0), "bn_expand2"},
{ERR_PACK(0,BN_F_BN_MOD_EXP_MONT,0), "BN_mod_exp_mont"},
{ERR_PACK(0,BN_F_BN_MOD_EXP_MONT_WORD,0), "BN_MOD_EXP_MONT_WORD"},
{ERR_PACK(0,BN_F_BN_MOD_INVERSE,0), "BN_mod_inverse"},
{ERR_PACK(0,BN_F_BN_MOD_MUL_RECIPROCAL,0), "BN_mod_mul_reciprocal"},
{ERR_PACK(0,BN_F_BN_MPI2BN,0), "BN_mpi2bn"},
......
......@@ -66,6 +66,7 @@
# include <dlfcn.h>
#endif
#define TABLE_SIZE 16
/* slow but works */
......@@ -91,42 +92,6 @@ err:
return(r);
}
#if 0
/* this one works - simple but works */
int BN_mod_exp(BIGNUM *r, BIGNUM *a, BIGNUM *p, BIGNUM *m, BN_CTX *ctx)
{
int i,bits,ret=0;
BIGNUM *v,*tmp;
BN_CTX_start(ctx);
v = BN_CTX_get(ctx);
tmp = BN_CTX_get(ctx);
if (v == NULL || tmp == NULL) goto err;
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; }
for (i=1; i<bits; i++)
{
if (!BN_sqr(tmp,v,ctx)) goto err;
if (!BN_mod(v,tmp,m,ctx)) goto err;
if (BN_is_bit_set(p,i))
{
if (!BN_mul(tmp,r,v,ctx)) goto err;
if (!BN_mod(r,tmp,m,ctx)) goto err;
}
}
ret=1;
err:
BN_CTX_end(ctx);
return(ret);
}
#endif
/* this one works - simple but works */
int BN_exp(BIGNUM *r, BIGNUM *a, BIGNUM *p, BN_CTX *ctx)
......@@ -163,6 +128,7 @@ err:
return(ret);
}
#ifdef ATALLA
/*
......@@ -330,6 +296,7 @@ int BN_mod_exp_atalla(BIGNUM *r, BIGNUM *a, const BIGNUM *p, const BIGNUM *m)
}
#endif /* def ATALLA */
int BN_mod_exp(BIGNUM *r, BIGNUM *a, const BIGNUM *p, const BIGNUM *m,
BN_CTX *ctx)
{
......@@ -354,7 +321,15 @@ int BN_mod_exp(BIGNUM *r, BIGNUM *a, const BIGNUM *p, const BIGNUM *m,
/* 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,NULL); }
{
if (a->top == 1)
{
BN_ULONG A = a->d[0];
ret=BN_mod_exp_mont_word(r,A,p,m,ctx,NULL);
}
else
ret=BN_mod_exp_mont(r,a,p,m,ctx,NULL);
}
else
#endif
#ifdef RECP_MUL_MOD
......@@ -370,7 +345,7 @@ int BN_mod_exp(BIGNUM *r, BIGNUM *a, const BIGNUM *p, const BIGNUM *m,
return(ret);
}
/* #ifdef RECP_MUL_MOD */
int BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
const BIGNUM *m, BN_CTX *ctx)
{
......@@ -485,9 +460,8 @@ err:
BN_RECP_CTX_free(&recp);
return(ret);
}
/* #endif */
/* #ifdef MONT_MUL_MOD */
int BN_mod_exp_mont(BIGNUM *rr, BIGNUM *a, const BIGNUM *p,
const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
{
......@@ -527,11 +501,9 @@ int BN_mod_exp_mont(BIGNUM *rr, BIGNUM *a, const BIGNUM *p,
/* If this is not done, things will break in the montgomery
* part */
#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;
......@@ -541,7 +513,8 @@ int BN_mod_exp_mont(BIGNUM *rr, BIGNUM *a, const BIGNUM *p,
ts=1;
if (BN_ucmp(a,m) >= 0)
{
BN_mod(&(val[0]),a,m,ctx);
if (!BN_mod(&(val[0]),a,m,ctx))
goto err;
aa= &(val[0]);
}
else
......@@ -635,7 +608,82 @@ err:
BN_clear_free(&(val[i]));
return(ret);
}
/* #endif */
int BN_mod_exp_mont_word(BIGNUM *rr, BN_ULONG a, const BIGNUM *p,
const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
/* if we had BN_mod_exp_mont_2, we could even use windowing in it */
{
int b, bits, ret=0;
BIGNUM *d, *r, *t;
BN_MONT_CTX *mont = NULL;
bn_check_top(p);
bn_check_top(m);
if (!(m->d[0] & 1))
{
BNerr(BN_F_BN_MOD_EXP_MONT_WORD,BN_R_CALLED_WITH_EVEN_MODULUS);
return(0);
}
bits = BN_num_bits(p);
if (bits == 0)
{
BN_one(rr);
return(1);
}
BN_CTX_start(ctx);
d = BN_CTX_get(ctx);
r = BN_CTX_get(ctx);
t = BN_CTX_get(ctx);
if (d == NULL || r == NULL || t == NULL) goto err;
#ifdef ATALLA
if (!tried_atalla)
{
BN_set_word(t, a);
if (BN_mod_exp_word_atalla(rr, t, p, m))
return 1;
}
/* If it fails, try the other methods */
#endif
if (in_mont != NULL)
mont=in_mont;
else
{
if ((mont = BN_MONT_CTX_new()) == NULL) goto err;
if (!BN_MONT_CTX_set(mont, m, ctx)) goto err;
}
if (!BN_to_montgomery(r, BN_value_one(), mont, ctx)) goto err;
for (b = bits-1; b >= 0; b--)
{
if (BN_is_bit_set(p, b))
{
if (!BN_mul_word(r, a))
goto err;
if (BN_ucmp(r, m) >= 0)
{
if (!BN_mod(t, r, m, ctx))
goto err;
{ BIGNUM *swap_tmp = r; r = t; t = swap_tmp; }
}
}
if (b > 0)
{
if (!BN_mod_mul_montgomery(r, r, r, mont, ctx))
goto err;
}
}
BN_from_montgomery(rr, r, mont, ctx);
ret = 1;
err:
if ((in_mont == NULL) && (mont != NULL)) BN_MONT_CTX_free(mont);
BN_CTX_end(ctx);
return(ret);
}
/* The old fallback, simple version :-) */
int BN_mod_exp_simple(BIGNUM *r, BIGNUM *a, BIGNUM *p, BIGNUM *m,
......
......@@ -193,19 +193,26 @@ err:
static int dh_bn_mod_exp(DH *dh, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
const BIGNUM *m, BN_CTX *ctx,
BN_MONT_CTX *m_ctx)
{
return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx);
}
{
if (a->top == 1)
{
BN_ULONG A = a->d[0];
return BN_mod_exp_mont_word(r,A,p,m,ctx,m_ctx);
}
else
return BN_mod_exp_mont(r,a,p,m,ctx,m_ctx);
}
static int dh_init(DH *dh)
{
{
dh->flags |= DH_FLAG_CACHE_MONT_P;
return(1);
}
}
static int dh_finish(DH *dh)
{
{
if(dh->method_mont_p)
BN_MONT_CTX_free((BN_MONT_CTX *)dh->method_mont_p);
return(1);
}
}
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