114 lines
2.4 KiB
C
114 lines
2.4 KiB
C
/*
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* Copyright (c) 2000, 2001, 2002 Virtual Unlimited B.V.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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/*!\file blockpad.c
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* \brief Blockcipher padding algorithms.
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* \author Bob Deblier <bob.deblier@pandora.be>
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* \ingroup BC_m
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*/
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#include "system.h"
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#include "blockpad.h"
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#include "debug.h"
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memchunk* pkcs5Pad(size_t blockbytes, memchunk* tmp)
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{
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if (tmp)
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{
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byte padvalue = blockbytes - (tmp->size % blockbytes);
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tmp = memchunkResize(tmp, tmp->size + padvalue);
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if (tmp)
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memset(tmp->data - padvalue, padvalue, padvalue);
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}
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return tmp;
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}
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memchunk* pkcs5Unpad(size_t blockbytes, memchunk* tmp)
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{
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if (tmp)
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{
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byte padvalue = tmp->data[tmp->size - 1];
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unsigned int i;
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if (padvalue > blockbytes)
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return (memchunk*) 0;
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for (i = (tmp->size - padvalue); i < (tmp->size - 1); i++)
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{
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if (tmp->data[i] != padvalue)
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return (memchunk*) 0;
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}
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tmp->size -= padvalue;
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/* tmp->data = (byte*) realloc(tmp->data, tmp->size); */
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}
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return tmp;
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}
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memchunk* pkcs5PadCopy(size_t blockbytes, const memchunk* src)
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{
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memchunk* tmp;
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byte padvalue = blockbytes - (src->size % blockbytes);
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if (src == (memchunk*) 0)
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return (memchunk*) 0;
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tmp = memchunkAlloc(src->size + padvalue);
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if (tmp)
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{
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memcpy(tmp->data, src->data, src->size);
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memset(tmp->data+src->size, padvalue, padvalue);
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}
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return tmp;
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}
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memchunk* pkcs5UnpadCopy(size_t blockbytes, const memchunk* src)
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{
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memchunk* tmp;
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byte padvalue;
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unsigned int i;
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if (src == (memchunk*) 0)
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return (memchunk*) 0;
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padvalue = src->data[src->size - 1];
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for (i = (src->size - padvalue); i < (src->size - 1); i++)
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{
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if (src->data[i] != padvalue)
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return (memchunk*) 0;
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}
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tmp = memchunkAlloc(src->size - padvalue);
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if (tmp)
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memcpy(tmp->data, src->data, tmp->size);
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return tmp;
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}
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