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-rw-r--r--openssl/crypto/bn/bn_mont.c732
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diff --git a/openssl/crypto/bn/bn_mont.c b/openssl/crypto/bn/bn_mont.c
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+/* crypto/bn/bn_mont.c */
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
+ * All rights reserved.
+ *
+ * This package is an SSL implementation written
+ * by Eric Young (eay@cryptsoft.com).
+ * The implementation was written so as to conform with Netscapes SSL.
+ *
+ * This library is free for commercial and non-commercial use as long as
+ * the following conditions are aheared to. The following conditions
+ * apply to all code found in this distribution, be it the RC4, RSA,
+ * lhash, DES, etc., code; not just the SSL code. The SSL documentation
+ * included with this distribution is covered by the same copyright terms
+ * except that the holder is Tim Hudson (tjh@cryptsoft.com).
+ *
+ * Copyright remains Eric Young's, and as such any Copyright notices in
+ * the code are not to be removed.
+ * If this package is used in a product, Eric Young should be given attribution
+ * as the author of the parts of the library used.
+ * This can be in the form of a textual message at program startup or
+ * in documentation (online or textual) provided with the package.
+ *
+ * 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 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 acknowledgement:
+ * "This product includes cryptographic software written by
+ * Eric Young (eay@cryptsoft.com)"
+ * The word 'cryptographic' can be left out if the rouines from the library
+ * being used are not cryptographic related :-).
+ * 4. If you include any Windows specific code (or a derivative thereof) from
+ * the apps directory (application code) you must include an acknowledgement:
+ * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
+ * ANY EXPRESS 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 AUTHOR OR 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.
+ *
+ * The licence and distribution terms for any publically available version or
+ * derivative of this code cannot be changed. i.e. this code cannot simply be
+ * 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
+ * http://security.ece.orst.edu/publications.html, e.g.
+ * http://security.ece.orst.edu/koc/papers/j37acmon.pdf and
+ * sections 3.8 and 4.2 in http://security.ece.orst.edu/koc/papers/r01rsasw.pdf
+ */
+
+#include <stdio.h>
+#include "cryptlib.h"
+#include "bn_lcl.h"
+
+#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
+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;
+ 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 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;
+ bn_correct_top(r);
+ return(1);
+ }
+ }
+#endif
+
+ BN_CTX_start(ctx);
+ tmp = BN_CTX_get(ctx);
+ if (tmp == NULL) goto err;
+
+ bn_check_top(tmp);
+ if (a == b)
+ {
+ if (!BN_sqr(tmp,a,ctx)) goto err;
+ }
+ else
+ {
+ if (!BN_mul(tmp,a,b,ctx)) goto err;
+ }
+ /* reduce from aRR to aR */
+#ifdef MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD
+ 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);
+ }
+
+#ifdef MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD
+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;
+
+ n= &(mont->N);
+ /* 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)) { ret->top=0; return(1); }
+
+ max=(nl+al+1); /* allow for overflow (no?) XXX */
+ if (bn_wexpand(r,max) == NULL) return(0);
+
+ r->neg^=n->neg;
+ np=n->d;
+ rp=r->d;
+ nrp= &(r->d[nl]);
+
+ /* clear the top words of T */
+ for (i=r->top; i<max; i++) /* memset? XXX */
+ r->d[i]=0;
+
+ 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);
+#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;
+ return(1);
+ }
+ al=r->top-ri;
+
+ 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[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);
+ 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;
+ ret->top=al;
+ ret->neg=r->neg;
+
+ rp=ret->d;
+ ap=&(r->d[ri]);
+ al-=4;
+ for (i=0; i<al; i+=4)
+ {
+ BN_ULONG t1,t2,t3,t4;
+
+ t1=ap[i+0];
+ t2=ap[i+1];
+ t3=ap[i+2];
+ t4=ap[i+3];
+ rp[i+0]=t1;
+ rp[i+1]=t2;
+ rp[i+2]=t3;
+ rp[i+3]=t4;
+ }
+ al+=4;
+ for (; i<al; i++)
+ rp[i]=ap[i];
+# endif
+#else /* !MONT_WORD */
+ BIGNUM *t1,*t2;
+
+ BN_CTX_start(ctx);
+ t1 = BN_CTX_get(ctx);
+ t2 = BN_CTX_get(ctx);
+ if (t1 == NULL || t2 == NULL) goto err;
+
+ if (!BN_copy(t1,a)) goto err;
+ BN_mask_bits(t1,mont->ri);
+
+ if (!BN_mul(t2,t1,&mont->Ni,ctx)) goto err;
+ BN_mask_bits(t2,mont->ri);
+
+ 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);
+ return(retn);
+ }
+#endif /* MONT_FROM_WORD___NON_DEFAULT_0_9_8_BUILD */
+
+BN_MONT_CTX *BN_MONT_CTX_new(void)
+ {
+ BN_MONT_CTX *ret;
+
+ if ((ret=(BN_MONT_CTX *)OPENSSL_malloc(sizeof(BN_MONT_CTX))) == NULL)
+ return(NULL);
+
+ BN_MONT_CTX_init(ret);
+ ret->flags=BN_FLG_MALLOCED;
+ return(ret);
+ }
+
+void BN_MONT_CTX_init(BN_MONT_CTX *ctx)
+ {
+ ctx->ri=0;
+ 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;
+ }
+
+void BN_MONT_CTX_free(BN_MONT_CTX *mont)
+ {
+ if(mont == NULL)
+ return;
+
+ BN_free(&(mont->RR));
+ BN_free(&(mont->N));
+ BN_free(&(mont->Ni));
+ if (mont->flags & BN_FLG_MALLOCED)
+ OPENSSL_free(mont);
+ }
+
+int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
+ {
+ int ret = 0;
+ BIGNUM *Ri,*R;
+
+ BN_CTX_start(ctx);
+ if((Ri = BN_CTX_get(ctx)) == NULL) goto err;
+ R= &(mont->RR); /* grab RR as a temp */
+ if (!BN_copy(&(mont->N),mod)) goto err; /* Set N */
+ mont->N.neg = 0;
+
+#ifdef MONT_WORD
+ {
+ 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 */
+ 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
+ /* Ri = R^-1 mod N*/
+ 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_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_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 */
+ { /* bignum version */
+ mont->ri=BN_num_bits(&mont->N);
+ 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)
+ 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;
+ }
+#endif
+
+ /* setup RR for conversions */
+ BN_zero(&(mont->RR));
+ if (!BN_set_bit(&(mont->RR),mont->ri*2)) goto err;
+ if (!BN_mod(&(mont->RR),&(mont->RR),&(mont->N),ctx)) goto err;
+
+ ret = 1;
+err:
+ 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);
+
+ 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;
+#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);
+ }
+
+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;
+ }
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-23 12:19:03 +0000