* 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
* sections 3.8 and 4.2 in http://security.ece.orst.edu/koc/papers/r01rsasw.pdf
*/
+#define OPENSSL_FIPSAPI
+
#include <stdio.h>
#include "cryptlib.h"
#include "bn_lcl.h"
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_ULONG *ap,*np,*rp,n0,v,carry;
+ int nl,max,i;
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); }
+ if (nl == 0) { ret->top=0; return(1); }
- max=(nl+al+1); /* allow for overflow (no?) XXX */
+ max=(2*nl); /* carry is stored separately */
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 */
#if 1
for (i=r->top; i<max; i++) /* memset? XXX */
- r->d[i]=0;
+ rp[i]=0;
#else
- memset(&(r->d[r->top]),0,(max-r->top)*sizeof(BN_ULONG));
+ memset(&(rp[r->top]),0,(max-r->top)*sizeof(BN_ULONG));
#endif
r->top=max;
#ifdef BN_COUNT
fprintf(stderr,"word BN_from_montgomery_word %d * %d\n",nl,nl);
#endif
- for (i=0; i<nl; i++)
+ for (carry=0, i=0; i<nl; i++, rp++)
{
#ifdef __TANDEM
{
#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++) ;
- }
+ v = (v+carry+rp[nl])&BN_MASK2;
+ carry |= (v != rp[nl]);
+ carry &= (v <= rp[nl]);
+ rp[nl]=v;
}
- bn_correct_top(r);
-
- /* mont->ri will be a multiple of the word size */
-#if 0
- BN_rshift(ret,r,mont->ri);
-#else
- if (r->top < ri)
- {
- ret->top=0;
- return(1);
- }
- al=r->top-ri;
- if (bn_wexpand(ret,al) == NULL) return(0);
+
+ if (bn_wexpand(ret,nl) == NULL) return(0);
+ ret->top=nl;
ret->neg=r->neg;
- ret->top=al;
rp=ret->d;
- ap=&(r->d[ri]);
- al-=4;
- for (i=0; i<al; i+=4)
+ ap=&(r->d[nl]);
+
+#define BRANCH_FREE 1
+#if BRANCH_FREE
+ {
+ BN_ULONG *nrp;
+ size_t m;
+
+ v=bn_sub_words(rp,ap,np,nl)-carry;
+ /* if subtraction result is real, then
+ * trick unconditional memcpy below to perform in-place
+ * "refresh" instead of actual copy. */
+ m=(0-(size_t)v);
+ nrp=(BN_ULONG *)(((PTR_SIZE_INT)rp&~m)|((PTR_SIZE_INT)ap&m));
+
+ for (i=0,nl-=4; i<nl; 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;
+ 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;
}
- al+=4;
- for (; i<al; i++)
- rp[i]=ap[i];
+ for (nl+=4; i<nl; i++)
+ rp[i]=nrp[i], ap[i]=0;
+ }
+#else
+ if (bn_sub_words (rp,ap,np,nl)-carry)
+ memcpy(rp,ap,nl*sizeof(BN_ULONG));
#endif
-
- if (BN_ucmp(ret, &(mont->N)) >= 0)
- {
- if (!BN_usub(ret,ret,&(mont->N))) return(0);
- }
+ bn_correct_top(r);
+ bn_correct_top(ret);
bn_check_top(ret);
return(1);
BN_init(&(ctx->RR));
BN_init(&(ctx->N));
BN_init(&(ctx->Ni));
+ ctx->n0[0] = ctx->n0[1] = 0;
ctx->flags=0;
}
BIGNUM tmod;
BN_ULONG buf[2];
+ BN_init(&tmod);
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)
+ /* 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;
BN_MONT_CTX *BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, int lock,
const BIGNUM *mod, BN_CTX *ctx)
{
- if (*pmont)
- return *pmont;
- CRYPTO_w_lock(lock);
+ int got_write_lock = 0;
+ BN_MONT_CTX *ret;
+
+ CRYPTO_r_lock(lock);
if (!*pmont)
{
- *pmont = BN_MONT_CTX_new();
- if (*pmont && !BN_MONT_CTX_set(*pmont, mod, ctx))
+ CRYPTO_r_unlock(lock);
+ CRYPTO_w_lock(lock);
+ got_write_lock = 1;
+
+ if (!*pmont)
{
- BN_MONT_CTX_free(*pmont);
- *pmont = NULL;
+ ret = BN_MONT_CTX_new();
+ if (ret && !BN_MONT_CTX_set(ret, mod, ctx))
+ BN_MONT_CTX_free(ret);
+ else
+ *pmont = ret;
}
}
- CRYPTO_w_unlock(lock);
- return *pmont;
+
+ ret = *pmont;
+
+ if (got_write_lock)
+ CRYPTO_w_unlock(lock);
+ else
+ CRYPTO_r_unlock(lock);
+
+ return ret;
}
projects / openssl.git / blobdiff