diff options
author | Geoff Thorpe <geoff@openssl.org> | 2004-03-25 04:32:24 +0000 |
---|---|---|
committer | Geoff Thorpe <geoff@openssl.org> | 2004-03-25 04:32:24 +0000 |
commit | c86f2054f39c7005bc03f91db2d7bcf38f0a92ac (patch) | |
tree | d44ff598397b7c8c61b254d32aaba1479a34deda /crypto/bn/bn_exp2.c | |
parent | 5c98b2caf5ce545fbf77611431c7084979da8177 (diff) |
Adjust various bignum functions to use BN_CTX for variables instead of
locally initialising their own.
NB: I've removed the "BN_clear_free()" loops for the exit-paths in some of
these functions, and that may be a major part of the performance
improvements we're seeing. The "free" part can be removed because we're
using BN_CTX. The "clear" part OTOH can be removed because BN_CTX
destruction automatically performs this task, so performing it inside
functions that may be called repeatedly is wasteful. This is currently safe
within openssl due to the fact that BN_CTX objects are never created for
longer than a single high-level operation. However, that is only because
there's currently no mechanism in openssl for thread-local storage. Beyond
that, this might be an issue for applications using the bignum API directly
and caching their own BN_CTX objects. The solution is to introduce a flag
to BN_CTX_start() that allows its variables to be automatically sanitised
on release during BN_CTX_end(). This way any higher-level function (and
perhaps the application) can specify this flag in its own
BN_CTX_start()/BN_CTX_end() pair, and this will cause inner-loop functions
specifying the flag to be ignored so that sanitisation is handled only once
back out at the higher level. I will be implementing this in the near
future.
Diffstat (limited to 'crypto/bn/bn_exp2.c')
-rw-r--r-- | crypto/bn/bn_exp2.c | 50 |
1 files changed, 22 insertions, 28 deletions
diff --git a/crypto/bn/bn_exp2.c b/crypto/bn/bn_exp2.c index 1223c678ce..b3f43cec8c 100644 --- a/crypto/bn/bn_exp2.c +++ b/crypto/bn/bn_exp2.c @@ -120,11 +120,11 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1, BN_CTX *ctx, BN_MONT_CTX *in_mont) { int i,j,bits,b,bits1,bits2,ret=0,wpos1,wpos2,window1,window2,wvalue1,wvalue2; - int r_is_one=1,ts1=0,ts2=0; + int r_is_one=1; BIGNUM *d,*r; const BIGNUM *a_mod_m; - /* TODO: BN_CTX??? */ - BIGNUM val1[TABLE_SIZE], val2[TABLE_SIZE]; + /* Tables of variables obtained from 'ctx' */ + BIGNUM *val1[TABLE_SIZE], *val2[TABLE_SIZE]; BN_MONT_CTX *mont=NULL; bn_check_top(a1); @@ -151,7 +151,9 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1, BN_CTX_start(ctx); d = BN_CTX_get(ctx); r = BN_CTX_get(ctx); - if (d == NULL || r == NULL) goto err; + val1[0] = BN_CTX_get(ctx); + val2[0] = BN_CTX_get(ctx); + if(!d || !r || !val1[0] || !val2[0]) goto err; if (in_mont != NULL) mont=in_mont; @@ -167,13 +169,11 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1, /* * Build table for a1: val1[i] := a1^(2*i + 1) mod m for i = 0 .. 2^(window1-1) */ - BN_init(&val1[0]); - ts1=1; if (a1->neg || BN_ucmp(a1,m) >= 0) { - if (!BN_mod(&(val1[0]),a1,m,ctx)) + if (!BN_mod(val1[0],a1,m,ctx)) goto err; - a_mod_m = &(val1[0]); + a_mod_m = val1[0]; } else a_mod_m = a1; @@ -184,32 +184,30 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1, goto err; } - if (!BN_to_montgomery(&(val1[0]),a_mod_m,mont,ctx)) goto err; + if (!BN_to_montgomery(val1[0],a_mod_m,mont,ctx)) goto err; if (window1 > 1) { - if (!BN_mod_mul_montgomery(d,&(val1[0]),&(val1[0]),mont,ctx)) goto err; + if (!BN_mod_mul_montgomery(d,val1[0],val1[0],mont,ctx)) goto err; j=1<<(window1-1); for (i=1; i<j; i++) { - BN_init(&(val1[i])); - if (!BN_mod_mul_montgomery(&(val1[i]),&(val1[i-1]),d,mont,ctx)) + if(((val1[i] = BN_CTX_get(ctx)) == NULL) || + !BN_mod_mul_montgomery(val1[i],val1[i-1], + d,mont,ctx)) goto err; } - ts1=i; } /* * Build table for a2: val2[i] := a2^(2*i + 1) mod m for i = 0 .. 2^(window2-1) */ - BN_init(&val2[0]); - ts2=1; if (a2->neg || BN_ucmp(a2,m) >= 0) { - if (!BN_mod(&(val2[0]),a2,m,ctx)) + if (!BN_mod(val2[0],a2,m,ctx)) goto err; - a_mod_m = &(val2[0]); + a_mod_m = val2[0]; } else a_mod_m = a2; @@ -219,19 +217,19 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1, ret = 1; goto err; } - if (!BN_to_montgomery(&(val2[0]),a_mod_m,mont,ctx)) goto err; + if (!BN_to_montgomery(val2[0],a_mod_m,mont,ctx)) goto err; if (window2 > 1) { - if (!BN_mod_mul_montgomery(d,&(val2[0]),&(val2[0]),mont,ctx)) goto err; + if (!BN_mod_mul_montgomery(d,val2[0],val2[0],mont,ctx)) goto err; j=1<<(window2-1); for (i=1; i<j; i++) { - BN_init(&(val2[i])); - if (!BN_mod_mul_montgomery(&(val2[i]),&(val2[i-1]),d,mont,ctx)) + if(((val2[i] = BN_CTX_get(ctx)) == NULL) || + !BN_mod_mul_montgomery(val2[i],val2[i-1], + d,mont,ctx)) goto err; } - ts2=i; } @@ -288,7 +286,7 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1, if (wvalue1 && b == wpos1) { /* wvalue1 is odd and < 2^window1 */ - if (!BN_mod_mul_montgomery(r,r,&(val1[wvalue1>>1]),mont,ctx)) + if (!BN_mod_mul_montgomery(r,r,val1[wvalue1>>1],mont,ctx)) goto err; wvalue1 = 0; r_is_one = 0; @@ -297,7 +295,7 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1, if (wvalue2 && b == wpos2) { /* wvalue2 is odd and < 2^window2 */ - if (!BN_mod_mul_montgomery(r,r,&(val2[wvalue2>>1]),mont,ctx)) + if (!BN_mod_mul_montgomery(r,r,val2[wvalue2>>1],mont,ctx)) goto err; wvalue2 = 0; r_is_one = 0; @@ -308,10 +306,6 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1, err: if ((in_mont == NULL) && (mont != NULL)) BN_MONT_CTX_free(mont); BN_CTX_end(ctx); - for (i=0; i<ts1; i++) - BN_clear_free(&(val1[i])); - for (i=0; i<ts2; i++) - BN_clear_free(&(val2[i])); bn_check_top(rr); return(ret); } |