X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=crypto%2Fbn%2Fbn_mont.c;h=b5d35d10be829f419f0d19212e6888e70da5f485;hb=231a737a82cecde336ef4eeebdc26469f8c44e98;hp=61416483cb26761b113935857fc677a5081eac4d;hpb=a0e7c8eede26b29b09057f48b8e51f46f8811ddd;p=oweals%2Fopenssl.git diff --git a/crypto/bn/bn_mont.c b/crypto/bn/bn_mont.c index 61416483cb..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: @@ -292,7 +399,7 @@ 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*/ @@ -350,3 +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; + }