diff options
Diffstat (limited to 'openssl/crypto/bn/bn_mont.c')
-rw-r--r-- | openssl/crypto/bn/bn_mont.c | 269 |
1 files changed, 52 insertions, 217 deletions
diff --git a/openssl/crypto/bn/bn_mont.c b/openssl/crypto/bn/bn_mont.c index 4799b152d..7224637ab 100644 --- a/openssl/crypto/bn/bn_mont.c +++ b/openssl/crypto/bn/bn_mont.c @@ -122,26 +122,10 @@ #define MONT_WORD /* use the faster word-based algorithm */ -#if defined(MONT_WORD) && defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2<=32) -/* This condition means we have a specific non-default build: - * In the 0.9.8 branch, OPENSSL_BN_ASM_MONT is normally not set for any - * BN_BITS2<=32 platform; an explicit "enable-montasm" is required. - * I.e., if we are here, the user intentionally deviates from the - * normal stable build to get better Montgomery performance from - * the 0.9.9-dev backport. - * - * In this case only, we also enable BN_from_montgomery_word() - * (another non-stable feature from 0.9.9-dev). - */ -#define MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD -#endif - -#ifdef MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD +#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) { @@ -153,11 +137,7 @@ int BN_mod_mul_montgomery(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, if (num>1 && a->top==num && b->top==num) { if (bn_wexpand(r,num) == NULL) return(0); -#if 0 /* for OpenSSL 0.9.9 mont->n0 */ if (bn_mul_mont(r->d,a->d,b->d,mont->N.d,mont->n0,num)) -#else - if (bn_mul_mont(r->d,a->d,b->d,mont->N.d,&mont->n0,num)) -#endif { r->neg = a->neg^b->neg; r->top = num; @@ -181,7 +161,7 @@ int BN_mod_mul_montgomery(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, if (!BN_mul(tmp,a,b,ctx)) goto err; } /* reduce from aRR to aR */ -#ifdef MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD +#ifdef MONT_WORD if (!BN_from_montgomery_word(r,tmp,mont)) goto err; #else if (!BN_from_montgomery(r,tmp,mont,ctx)) goto err; @@ -193,7 +173,7 @@ err: return(ret); } -#ifdef MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD +#ifdef MONT_WORD static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont) { BIGNUM *n; @@ -217,15 +197,15 @@ static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont) nrp= &(r->d[nl]); /* clear the top words of T */ +#if 1 for (i=r->top; i<max; i++) /* memset? XXX */ r->d[i]=0; +#else + memset(&(r->d[r->top]),0,(max-r->top)*sizeof(BN_ULONG)); +#endif r->top=max; -#if 0 /* for OpenSSL 0.9.9 mont->n0 */ n0=mont->n0[0]; -#else - n0=mont->n0; -#endif #ifdef BN_COUNT fprintf(stderr,"word BN_from_montgomery_word %d * %d\n",nl,nl); @@ -270,6 +250,8 @@ static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont) } 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) */ @@ -317,164 +299,8 @@ static int BN_from_montgomery_word(BIGNUM *ret, BIGNUM *r, BN_MONT_CTX *mont) rp[i]=nrp[i], ap[i]=0; bn_correct_top(r); bn_correct_top(ret); - bn_check_top(ret); - - return(1); - } - -int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont, - BN_CTX *ctx) - { - int retn=0; - 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); - return retn; - } - -#else /* !MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD */ - -int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont, - BN_CTX *ctx) - { - int retn=0; - -#ifdef MONT_WORD - BIGNUM *n,*r; - 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); } - - max=(nl+al+1); /* allow for overflow (no?) XXX */ - if (bn_wexpand(r,max) == NULL) goto err; - - r->neg=a->neg^n->neg; - np=n->d; - rp=r->d; - nrp= &(r->d[nl]); - - /* clear the top words of T */ -#if 1 - for (i=r->top; i<max; i++) /* memset? XXX */ - r->d[i]=0; #else - memset(&(r->d[r->top]),0,(max-r->top)*sizeof(BN_ULONG)); -#endif - - r->top=max; - n0=mont->n0; - -#ifdef BN_COUNT - fprintf(stderr,"word BN_from_montgomery %d * %d\n",nl,nl); -#endif - for (i=0; i<nl; i++) - { -#ifdef __TANDEM - { - long long t1; - long long t2; - long long t3; - t1 = rp[0] * (n0 & 0177777); - t2 = 037777600000l; - t2 = n0 & t2; - t3 = rp[0] & 0177777; - t2 = (t3 * t2) & BN_MASK2; - t1 = t1 + t2; - v=bn_mul_add_words(rp,np,nl,(BN_ULONG) t1); - } -#else - v=bn_mul_add_words(rp,np,nl,(rp[0]*n0)&BN_MASK2); -#endif - nrp++; - rp++; - if (((nrp[-1]+=v)&BN_MASK2) >= v) - continue; - else - { - if (((++nrp[0])&BN_MASK2) != 0) continue; - if (((++nrp[1])&BN_MASK2) != 0) continue; - for (x=2; (((++nrp[x])&BN_MASK2) == 0); x++) ; - } - } - 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; - 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[ri]); - - { - size_t m1,m2; - - v=bn_sub_words(rp,ap,np,ri); - /* this ----------------^^ works even in al<ri case - * thanks to zealous zeroing of top of the vector in the - * beginning. */ - - /* if (al==ri && !v) || al>ri) 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<ri */ - m2=0-(size_t)(((ri-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)); - } - - /* 'i<ri' is chosen to eliminate dependency on input data, even - * though it results in redundant copy in al<ri case. */ - for (i=0,ri-=4; i<ri; i+=4) - { - BN_ULONG t1,t2,t3,t4; - - t1=nrp[i+0]; - t2=nrp[i+1]; - t3=nrp[i+2]; ap[i+0]=0; - t4=nrp[i+3]; ap[i+1]=0; - rp[i+0]=t1; ap[i+2]=0; - rp[i+1]=t2; ap[i+3]=0; - rp[i+2]=t3; - rp[i+3]=t4; - } - for (ri+=4; i<ri; i++) - rp[i]=nrp[i], ap[i]=0; - bn_correct_top(r); - bn_correct_top(ret); -# else - if (bn_wexpand(ret,al) == NULL) goto err; + if (bn_wexpand(ret,al) == NULL) return(0); ret->top=al; ret->neg=r->neg; @@ -497,8 +323,30 @@ int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont, al+=4; for (; i<al; i++) rp[i]=ap[i]; -# endif -#else /* !MONT_WORD */ + + if (BN_ucmp(ret, &(mont->N)) >= 0) + { + if (!BN_usub(ret,ret,&(mont->N))) return(0); + } +#endif + 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); @@ -515,21 +363,18 @@ int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont, if (!BN_mul(t1,t2,&mont->N,ctx)) goto err; if (!BN_add(t2,a,t1)) goto err; if (!BN_rshift(ret,t2,mont->ri)) 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: BN_CTX_end(ctx); +#endif /* MONT_WORD */ return(retn); } -#endif /* MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD */ BN_MONT_CTX *BN_MONT_CTX_new(void) { @@ -549,11 +394,7 @@ void BN_MONT_CTX_init(BN_MONT_CTX *ctx) BN_init(&(ctx->RR)); BN_init(&(ctx->N)); BN_init(&(ctx->Ni)); -#if 0 /* for OpenSSL 0.9.9 mont->n0 */ ctx->n0[0] = ctx->n0[1] = 0; -#else - ctx->n0 = 0; -#endif ctx->flags=0; } @@ -585,26 +426,22 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx) BIGNUM tmod; BN_ULONG buf[2]; - mont->ri=(BN_num_bits(mod)+(BN_BITS2-1))/BN_BITS2*BN_BITS2; - BN_zero(R); -#if 0 /* for OpenSSL 0.9.9 mont->n0, would be "#if defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2<=32)", - only certain BN_BITS2<=32 platforms actually need this */ - if (!(BN_set_bit(R,2*BN_BITS2))) goto err; /* R */ -#else - if (!(BN_set_bit(R,BN_BITS2))) goto err; /* R */ -#endif - - buf[0]=mod->d[0]; /* tmod = N mod word size */ - buf[1]=0; - BN_init(&tmod); tmod.d=buf; - tmod.top = buf[0] != 0 ? 1 : 0; tmod.dmax=2; tmod.neg=0; -#if 0 /* for OpenSSL 0.9.9 mont->n0, would be "#if defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2<=32)"; - only certain BN_BITS2<=32 platforms actually need this */ + mont->ri=(BN_num_bits(mod)+(BN_BITS2-1))/BN_BITS2*BN_BITS2; + +#if defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2<=32) + /* Only certain BN_BITS2<=32 platforms actually make use of + * n0[1], and we could use the #else case (with a shorter R + * value) for the others. However, currently only the assembler + * files do know which is which. */ + + BN_zero(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; @@ -632,6 +469,12 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx) 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.top = buf[0] != 0 ? 1 : 0; /* Ri = R^-1 mod N*/ if ((BN_mod_inverse(Ri,R,&tmod,ctx)) == NULL) goto err; @@ -647,12 +490,8 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx) if (!BN_div(Ri,NULL,Ri,&tmod,ctx)) goto err; /* Ni = (R*Ri-1)/N, * keep only least significant word: */ -# if 0 /* for OpenSSL 0.9.9 mont->n0 */ mont->n0[0] = (Ri->top > 0) ? Ri->d[0] : 0; mont->n0[1] = 0; -# else - mont->n0 = (Ri->top > 0) ? Ri->d[0] : 0; -# endif #endif } #else /* !MONT_WORD */ @@ -689,12 +528,8 @@ BN_MONT_CTX *BN_MONT_CTX_copy(BN_MONT_CTX *to, BN_MONT_CTX *from) if (!BN_copy(&(to->N),&(from->N))) return NULL; if (!BN_copy(&(to->Ni),&(from->Ni))) return NULL; to->ri=from->ri; -#if 0 /* for OpenSSL 0.9.9 mont->n0 */ to->n0[0]=from->n0[0]; to->n0[1]=from->n0[1]; -#else - to->n0=from->n0; -#endif return(to); } |