X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=crypto%2Fbn%2Fbn_mont.c;h=b5d35d10be829f419f0d19212e6888e70da5f485;hb=231a737a82cecde336ef4eeebdc26469f8c44e98;hp=14650ab9d5a4e2c8c77898ae12fccb9d066006cc;hpb=b6358c89a10128692875fb92921b663c4d079a1e;p=oweals%2Fopenssl.git diff --git a/crypto/bn/bn_mont.c b/crypto/bn/bn_mont.c index 14650ab9d5..b5d35d10be 100644 --- a/crypto/bn/bn_mont.c +++ b/crypto/bn/bn_mont.c @@ -55,6 +55,59 @@ * copied and put under another distribution licence * [including the GNU Public Licence.] */ +/* ==================================================================== + * Copyright (c) 1998-2006 The OpenSSL Project. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. All advertising materials mentioning features or use of this + * software must display the following acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" + * + * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to + * endorse or promote products derived from this software without + * prior written permission. For written permission, please contact + * openssl-core@openssl.org. + * + * 5. Products derived from this software may not be called "OpenSSL" + * nor may "OpenSSL" appear in their names without prior written + * permission of the OpenSSL Project. + * + * 6. Redistributions of any form whatsoever must retain the following + * acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit (http://www.openssl.org/)" + * + * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY + * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR + * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + * ==================================================================== + * + * This product includes cryptographic software written by Eric Young + * (eay@cryptsoft.com). This product includes software written by Tim + * Hudson (tjh@cryptsoft.com). + * + */ /* * Details about Montgomery multiplication algorithms can be found at @@ -123,7 +176,6 @@ int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont, max=(nl+al+1); /* allow for overflow (no?) XXX */ if (bn_wexpand(r,max) == NULL) goto err; - if (bn_wexpand(ret,max) == NULL) goto err; r->neg=a->neg^n->neg; np=n->d; @@ -175,19 +227,72 @@ int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont, } bn_correct_top(r); - /* mont->ri will be a multiple of the word size */ -#if 0 - BN_rshift(ret,r,mont->ri); -#else - ret->neg = r->neg; - x=ri; + /* mont->ri will be a multiple of the word size and below code + * is kind of BN_rshift(ret,r,mont->ri) equivalent */ + if (r->top <= ri) + { + ret->top=0; + retn=1; + goto err; + } + al=r->top-ri; + +# define BRANCH_FREE 1 +# if BRANCH_FREE + if (bn_wexpand(ret,ri) == NULL) goto err; + x=0-(((al-ri)>>(sizeof(al)*8-1))&1); + ret->top=x=(ri&~x)|(al&x); /* min(ri,al) */ + ret->neg=r->neg; + rp=ret->d; - ap= &(r->d[x]); - if (r->top < x) - al=0; - else - al=r->top-x; + ap=&(r->d[ri]); + + { + size_t m1,m2; + + v=bn_sub_words(rp,ap,np,ri); + /* this ----------------^^ works even in alri) nrp=rp; else nrp=ap; */ + /* in other words if subtraction result is real, then + * trick unconditional memcpy below to perform in-place + * "refresh" instead of actual copy. */ + m1=0-(size_t)(((al-ri)>>(sizeof(al)*8-1))&1); /* al>(sizeof(al)*8-1))&1); /* al>ri */ + m1|=m2; /* (al!=ri) */ + m1|=(0-(size_t)v); /* (al!=ri || v) */ + m1&=~m2; /* (al!=ri || v) && !al>ri */ + nrp=(BN_ULONG *)(((size_t)rp&~m1)|((size_t)ap&m1)); + } + + /* 'itop=al; + ret->neg=r->neg; + + rp=ret->d; + ap=&(r->d[ri]); al-=4; for (i=0; iri)) goto err; #endif /* MONT_WORD */ +#if !defined(BRANCH_FREE) || BRANCH_FREE==0 if (BN_ucmp(ret, &(mont->N)) >= 0) { if (!BN_usub(ret,ret,&(mont->N))) goto err; } +#endif retn=1; bn_check_top(ret); err: @@ -271,11 +378,13 @@ void BN_MONT_CTX_free(BN_MONT_CTX *mont) int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx) { - BIGNUM Ri,*R; + int ret = 0; + BIGNUM *Ri,*R; - BN_init(&Ri); + BN_CTX_start(ctx); + if((Ri = BN_CTX_get(ctx)) == NULL) goto err; R= &(mont->RR); /* grab RR as a temp */ - BN_copy(&(mont->N),mod); /* Set N */ + if (!BN_copy(&(mont->N),mod)) goto err; /* Set N */ mont->N.neg = 0; #ifdef MONT_WORD @@ -290,26 +399,25 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx) buf[0]=mod->d[0]; /* tmod = N mod word size */ buf[1]=0; tmod.d=buf; - tmod.top=1; + tmod.top = buf[0] != 0 ? 1 : 0; tmod.dmax=2; tmod.neg=0; /* Ri = R^-1 mod N*/ - if ((BN_mod_inverse(&Ri,R,&tmod,ctx)) == NULL) + if ((BN_mod_inverse(Ri,R,&tmod,ctx)) == NULL) goto err; - if (!BN_lshift(&Ri,&Ri,BN_BITS2)) goto err; /* R*Ri */ - if (!BN_is_zero(&Ri)) + if (!BN_lshift(Ri,Ri,BN_BITS2)) goto err; /* R*Ri */ + if (!BN_is_zero(Ri)) { - if (!BN_sub_word(&Ri,1)) goto err; + if (!BN_sub_word(Ri,1)) goto err; } else /* if N mod word size == 1 */ { - if (!BN_set_word(&Ri,BN_MASK2)) goto err; /* Ri-- (mod word size) */ + if (!BN_set_word(Ri,BN_MASK2)) goto err; /* Ri-- (mod word size) */ } - if (!BN_div(&Ri,NULL,&Ri,&tmod,ctx)) goto err; + if (!BN_div(Ri,NULL,Ri,&tmod,ctx)) goto err; /* Ni = (R*Ri-1)/N, * keep only least significant word: */ - mont->n0 = (Ri.top > 0) ? Ri.d[0] : 0; - BN_free(&Ri); + mont->n0 = (Ri->top > 0) ? Ri->d[0] : 0; } #else /* !MONT_WORD */ { /* bignum version */ @@ -317,13 +425,12 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx) BN_zero(R); if (!BN_set_bit(R,mont->ri)) goto err; /* R = 2^ri */ /* Ri = R^-1 mod N*/ - if ((BN_mod_inverse(&Ri,R,&mont->N,ctx)) == NULL) + if ((BN_mod_inverse(Ri,R,&mont->N,ctx)) == NULL) goto err; - if (!BN_lshift(&Ri,&Ri,mont->ri)) goto err; /* R*Ri */ - if (!BN_sub_word(&Ri,1)) goto err; + if (!BN_lshift(Ri,Ri,mont->ri)) goto err; /* R*Ri */ + if (!BN_sub_word(Ri,1)) goto err; /* Ni = (R*Ri-1) / N */ - if (!BN_div(&(mont->Ni),NULL,&Ri,&mont->N,ctx)) goto err; - BN_free(&Ri); + if (!BN_div(&(mont->Ni),NULL,Ri,&mont->N,ctx)) goto err; } #endif @@ -332,9 +439,10 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx) if (!BN_set_bit(&(mont->RR),mont->ri*2)) goto err; if (!BN_mod(&(mont->RR),&(mont->RR),&(mont->N),ctx)) goto err; - return(1); + ret = 1; err: - return(0); + BN_CTX_end(ctx); + return ret; } BN_MONT_CTX *BN_MONT_CTX_copy(BN_MONT_CTX *to, BN_MONT_CTX *from) @@ -349,3 +457,35 @@ BN_MONT_CTX *BN_MONT_CTX_copy(BN_MONT_CTX *to, BN_MONT_CTX *from) return(to); } +BN_MONT_CTX *BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, int lock, + const BIGNUM *mod, BN_CTX *ctx) + { + int got_write_lock = 0; + BN_MONT_CTX *ret; + + CRYPTO_r_lock(lock); + if (!*pmont) + { + CRYPTO_r_unlock(lock); + CRYPTO_w_lock(lock); + got_write_lock = 1; + + if (!*pmont) + { + ret = BN_MONT_CTX_new(); + if (ret && !BN_MONT_CTX_set(ret, mod, ctx)) + BN_MONT_CTX_free(ret); + else + *pmont = ret; + } + } + + ret = *pmont; + + if (got_write_lock) + CRYPTO_w_unlock(lock); + else + CRYPTO_r_unlock(lock); + + return ret; + }