/* * Copyright (c) 2000-2001 Apple Computer, Inc. All Rights Reserved. * * The contents of this file constitute Original Code as defined in and are * subject to the Apple Public Source License Version 1.2 (the 'License'). * You may not use this file except in compliance with the License. Please obtain * a copy of the License at http://www.apple.com/publicsource and read it before * using this file. * * This Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the * specific language governing rights and limitations under the License. */ /* crypto/bn/bn_shift.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.] */ #include <stdio.h> #include "cryptlib.h" #include "bn_lcl.h" int BN_lshift1(BIGNUM *r, BIGNUM *a) { register BN_ULONG *ap,*rp,t,c; int i; if (r != a) { r->neg=a->neg; if (bn_wexpand(r,a->top+1) == NULL) return(0); r->top=a->top; } else { if (bn_wexpand(r,a->top+1) == NULL) return(0); } ap=a->d; rp=r->d; c=0; for (i=0; i<a->top; i++) { t= *(ap++); *(rp++)=((t<<1)|c)&BN_MASK2; c=(t & BN_TBIT)?1:0; } if (c) { *rp=1; r->top++; } return(1); } int BN_rshift1(BIGNUM *r, BIGNUM *a) { BN_ULONG *ap,*rp,t,c; int i; if (BN_is_zero(a)) { BN_zero(r); return(1); } if (a != r) { if (bn_wexpand(r,a->top) == NULL) return(0); r->top=a->top; r->neg=a->neg; } ap=a->d; rp=r->d; c=0; for (i=a->top-1; i>=0; i--) { t=ap[i]; rp[i]=((t>>1)&BN_MASK2)|c; c=(t&1)?BN_TBIT:0; } bn_fix_top(r); return(1); } int BN_lshift(BIGNUM *r, const BIGNUM *a, int n) { int i,nw,lb,rb; BN_ULONG *t,*f; BN_ULONG l; r->neg=a->neg; if (bn_wexpand(r,a->top+(n/BN_BITS2)+1) == NULL) return(0); nw=n/BN_BITS2; lb=n%BN_BITS2; rb=BN_BITS2-lb; f=a->d; t=r->d; t[a->top+nw]=0; if (lb == 0) for (i=a->top-1; i>=0; i--) t[nw+i]=f[i]; else for (i=a->top-1; i>=0; i--) { l=f[i]; t[nw+i+1]|=(l>>rb)&BN_MASK2; t[nw+i]=(l<<lb)&BN_MASK2; } memset(t,0,nw*sizeof(t[0])); /* for (i=0; i<nw; i++) t[i]=0;*/ r->top=a->top+nw+1; bn_fix_top(r); return(1); } int BN_rshift(BIGNUM *r, BIGNUM *a, int n) { int i,j,nw,lb,rb; BN_ULONG *t,*f; BN_ULONG l,tmp; nw=n/BN_BITS2; rb=n%BN_BITS2; lb=BN_BITS2-rb; if (nw > a->top) { BN_zero(r); return(1); } if (r != a) { r->neg=a->neg; if (bn_wexpand(r,a->top-nw+1) == NULL) return(0); } f= &(a->d[nw]); t=r->d; j=a->top-nw; r->top=j; if (rb == 0) { for (i=j+1; i > 0; i--) *(t++)= *(f++); } else { l= *(f++); for (i=1; i<j; i++) { tmp =(l>>rb)&BN_MASK2; l= *(f++); *(t++) =(tmp|(l<<lb))&BN_MASK2; } *(t++) =(l>>rb)&BN_MASK2; } *t=0; bn_fix_top(r); return(1); }