X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fbn%2Fbn_mont.c;h=594d95940fdf86d99eaae4c7d4bc51712694e842;hp=8cf1febaccad8579bcc13d91caf55d520d1c25e1;hb=6b6443dead7b8c691ec8b3ae135ad989bbb1c3a1;hpb=fe03519704d5f533722e061009ca079e7217cfd2 diff --git a/crypto/bn/bn_mont.c b/crypto/bn/bn_mont.c index 8cf1febacc..594d95940f 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 @@ -69,20 +122,36 @@ #define MONT_WORD /* use the faster word-based algorithm */ -int BN_mod_mul_montgomery(BIGNUM *r, BIGNUM *a, BIGNUM *b, +#ifdef MONT_WORD +static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont); +#endif + +int BN_mod_mul_montgomery(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_MONT_CTX *mont, BN_CTX *ctx) { - BIGNUM *tmp,*tmp2; + BIGNUM *tmp; int ret=0; +#if defined(OPENSSL_BN_ASM_MONT) && defined(MONT_WORD) + int num = mont->N.top; + + if (num>1 && a->top==num && b->top==num) + { + if (bn_wexpand(r,num) == NULL) return(0); + if (bn_mul_mont(r->d,a->d,b->d,mont->N.d,mont->n0,num)) + { + r->neg = a->neg^b->neg; + r->top = num; + bn_correct_top(r); + return(1); + } + } +#endif BN_CTX_start(ctx); tmp = BN_CTX_get(ctx); - tmp2 = BN_CTX_get(ctx); - if (tmp == NULL || tmp2 == NULL) goto err; + if (tmp == NULL) goto err; bn_check_top(tmp); - bn_check_top(tmp2); - if (a == b) { if (!BN_sqr(tmp,a,ctx)) goto err; @@ -92,42 +161,37 @@ int BN_mod_mul_montgomery(BIGNUM *r, BIGNUM *a, BIGNUM *b, if (!BN_mul(tmp,a,b,ctx)) goto err; } /* reduce from aRR to aR */ +#ifdef MONT_WORD + if (!BN_from_montgomery_word(r,tmp,mont)) goto err; +#else if (!BN_from_montgomery(r,tmp,mont,ctx)) goto err; +#endif + bn_check_top(r); ret=1; err: BN_CTX_end(ctx); return(ret); } -int BN_from_montgomery(BIGNUM *ret, BIGNUM *a, BN_MONT_CTX *mont, - BN_CTX *ctx) - { - int retn=0; - #ifdef MONT_WORD - BIGNUM *n,*r; +static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont) + { + BIGNUM *n; BN_ULONG *ap,*np,*rp,n0,v,*nrp; int al,nl,max,i,x,ri; - BN_CTX_start(ctx); - if ((r = BN_CTX_get(ctx)) == NULL) goto err; - - if (!BN_copy(r,a)) goto err; n= &(mont->N); - - ap=a->d; /* mont->ri is the size of mont->N in bits (rounded up to the word size) */ al=ri=mont->ri/BN_BITS2; - + nl=n->top; - if ((al == 0) || (nl == 0)) { r->top=0; return(1); } + if ((al == 0) || (nl == 0)) { ret->top=0; return(1); } 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; + if (bn_wexpand(r,max) == NULL) return(0); - r->neg=a->neg^n->neg; + r->neg^=n->neg; np=n->d; rp=r->d; nrp= &(r->d[nl]); @@ -141,10 +205,10 @@ int BN_from_montgomery(BIGNUM *ret, BIGNUM *a, BN_MONT_CTX *mont, #endif r->top=max; - n0=mont->n0; + n0=mont->n0[0]; #ifdef BN_COUNT - printf("word BN_from_montgomery %d * %d\n",nl,nl); + fprintf(stderr,"word BN_from_montgomery_word %d * %d\n",nl,nl); #endif for (i=0; iri will be a multiple of the word size */ -#if 0 - BN_rshift(ret,r,mont->ri); -#else - ret->neg = r->neg; - x=ri; + bn_correct_top(r); + + /* 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; + return(1); + } + al=r->top-ri; + +#define BRANCH_FREE 1 +#if BRANCH_FREE + if (bn_wexpand(ret,ri) == NULL) return(0); + 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]); + nrp=ap; + + /* This 'if' denotes violation of 2*MN.d[ri-1]>>(BN_BITS2-2))!=0) + { + size_t m1,m2; + + v=bn_sub_words(rp,ap,mont->N.d,ri); + /* if (al==ri && !v) || al>ri) nrp=rp; */ + /* in other words if subtraction result is real, then + * trick unconditional memcpy below to make "refresh" + * instead of real copy. */ + m1=0-(size_t)(((al-ri)>>(sizeof(al)*8-1))&1); /* al>(sizeof(al)*8-1))&1); /* al>ri */ + m1=~(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)); + } + + for (i=0,ri-=4; itop=al; + ret->neg=r->neg; + + rp=ret->d; + ap=&(r->d[ri]); al-=4; for (i=0; iN)) >= 0) + { + if (!BN_usub(ret,ret,&(mont->N))) return(0); + } #endif -#else /* !MONT_WORD */ + bn_check_top(ret); + + return(1); + } +#endif /* MONT_WORD */ + +int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont, + BN_CTX *ctx) + { + int retn=0; +#ifdef MONT_WORD + BIGNUM *t; + + BN_CTX_start(ctx); + if ((t = BN_CTX_get(ctx)) && BN_copy(t,a)) + retn = BN_from_montgomery_word(ret,t,mont); + BN_CTX_end(ctx); +#else /* !MONT_WORD */ BIGNUM *t1,*t2; BN_CTX_start(ctx); @@ -224,16 +360,17 @@ int BN_from_montgomery(BIGNUM *ret, BIGNUM *a, BN_MONT_CTX *mont, if (!BN_mul(t1,t2,&mont->N,ctx)) goto err; if (!BN_add(t2,a,t1)) goto err; - BN_rshift(ret,t2,mont->ri); -#endif /* MONT_WORD */ + if (!BN_rshift(ret,t2,mont->ri)) goto err; if (BN_ucmp(ret, &(mont->N)) >= 0) { - BN_usub(ret,ret,&(mont->N)); + if (!BN_usub(ret,ret,&(mont->N))) goto err; } retn=1; + bn_check_top(ret); err: BN_CTX_end(ctx); +#endif /* MONT_WORD */ return(retn); } @@ -272,75 +409,150 @@ 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 { BIGNUM tmod; BN_ULONG buf[2]; + tmod.d=buf; + tmod.dmax=2; + tmod.neg=0; + mont->ri=(BN_num_bits(mod)+(BN_BITS2-1))/BN_BITS2*BN_BITS2; + +#if defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2<=32) BN_zero(R); - BN_set_bit(R,BN_BITS2); /* R */ + if (!(BN_set_bit(R,2*BN_BITS2))) goto err; + + tmod.top=0; + if ((buf[0] = mod->d[0])) tmod.top=1; + if ((buf[1] = mod->top>1 ? mod->d[1] : 0)) tmod.top=2; + + if ((BN_mod_inverse(Ri,R,&tmod,ctx)) == NULL) + goto err; + if (!BN_lshift(Ri,Ri,2*BN_BITS2)) goto err; /* R*Ri */ + if (!BN_is_zero(Ri)) + { + if (!BN_sub_word(Ri,1)) goto err; + } + else /* if N mod word size == 1 */ + { + if (bn_expand(Ri,(int)sizeof(BN_ULONG)*2) == NULL) + goto err; + /* Ri-- (mod double word size) */ + Ri->neg=0; + Ri->d[0]=BN_MASK2; + Ri->d[1]=BN_MASK2; + Ri->top=2; + } + if (!BN_div(Ri,NULL,Ri,&tmod,ctx)) goto err; + /* Ni = (R*Ri-1)/N, + * keep only couple of least significant words: */ + mont->n0[0] = (Ri->top > 0) ? Ri->d[0] : 0; + mont->n0[1] = (Ri->top > 1) ? Ri->d[1] : 0; +#else + BN_zero(R); + if (!(BN_set_bit(R,BN_BITS2))) goto err; /* R */ buf[0]=mod->d[0]; /* tmod = N mod word size */ buf[1]=0; - tmod.d=buf; - tmod.top=1; - tmod.dmax=2; - tmod.neg=mod->neg; + tmod.top = buf[0] != 0 ? 1 : 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; - BN_lshift(&Ri,&Ri,BN_BITS2); /* R*Ri */ - if (!BN_is_zero(&Ri)) - BN_sub_word(&Ri,1); + if (!BN_lshift(Ri,Ri,BN_BITS2)) goto err; /* R*Ri */ + if (!BN_is_zero(Ri)) + { + if (!BN_sub_word(Ri,1)) goto err; + } else /* if N mod word size == 1 */ - BN_set_word(&Ri,BN_MASK2); /* Ri-- (mod word size) */ - BN_div(&Ri,NULL,&Ri,&tmod,ctx); /* Ni = (R*Ri-1)/N, - * keep only least significant word: */ - mont->n0=Ri.d[0]; - BN_free(&Ri); + { + if (!BN_set_word(Ri,BN_MASK2)) goto err; /* Ri-- (mod word size) */ + } + if (!BN_div(Ri,NULL,Ri,&tmod,ctx)) goto err; + /* Ni = (R*Ri-1)/N, + * keep only least significant word: */ + mont->n0[0] = (Ri->top > 0) ? Ri->d[0] : 0; + mont->n0[1] = 0; +#endif } #else /* !MONT_WORD */ { /* bignum version */ - mont->ri=BN_num_bits(mod); + mont->ri=BN_num_bits(&mont->N); BN_zero(R); - BN_set_bit(R,mont->ri); /* R = 2^ri */ - /* Ri = R^-1 mod N*/ - if ((BN_mod_inverse(&Ri,R,mod,ctx)) == NULL) + 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) goto err; - BN_lshift(&Ri,&Ri,mont->ri); /* R*Ri */ - BN_sub_word(&Ri,1); + if (!BN_lshift(Ri,Ri,mont->ri)) goto err; /* R*Ri */ + if (!BN_sub_word(Ri,1)) goto err; /* Ni = (R*Ri-1) / N */ - BN_div(&(mont->Ni),NULL,&Ri,mod,ctx); - BN_free(&Ri); + if (!BN_div(&(mont->Ni),NULL,Ri,&mont->N,ctx)) goto err; } #endif /* setup RR for conversions */ BN_zero(&(mont->RR)); - BN_set_bit(&(mont->RR),mont->ri*2); - BN_mod(&(mont->RR),&(mont->RR),&(mont->N),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) { if (to == from) return(to); - BN_copy(&(to->RR),&(from->RR)); - BN_copy(&(to->N),&(from->N)); - BN_copy(&(to->Ni),&(from->Ni)); + if (!BN_copy(&(to->RR),&(from->RR))) return NULL; + if (!BN_copy(&(to->N),&(from->N))) return NULL; + if (!BN_copy(&(to->Ni),&(from->Ni))) return NULL; to->ri=from->ri; - to->n0=from->n0; + to->n0[0]=from->n0[0]; + to->n0[1]=from->n0[1]; 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; + }