175 lines
4.4 KiB
C
175 lines
4.4 KiB
C
/*
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* Copyright (C) 1998,1999,2000,2001,2002 Nikos Mavroyanopoulos
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*
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* This library is free software; you can redistribute it and/or modify it
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* under the terms of the GNU Library General Public License as published
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* by the Free Software Foundation; either version 2 of the License, or
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* (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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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#include <libdefs.h>
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#include <mcrypt_modules.h>
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#define _init_mcrypt ofb_LTX__init_mcrypt
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#define _mcrypt_set_state ofb_LTX__mcrypt_set_state
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#define _mcrypt_get_state ofb_LTX__mcrypt_get_state
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#define _end_mcrypt ofb_LTX__end_mcrypt
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#define _mcrypt ofb_LTX__mcrypt
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#define _mdecrypt ofb_LTX__mdecrypt
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#define _has_iv ofb_LTX__has_iv
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#define _is_block_mode ofb_LTX__is_block_mode
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#define _is_block_algorithm_mode ofb_LTX__is_block_algorithm_mode
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#define _mcrypt_get_modes_name ofb_LTX__mcrypt_get_modes_name
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#define _mcrypt_mode_get_size ofb_LTX__mcrypt_mode_get_size
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#define _mcrypt_mode_version ofb_LTX__mcrypt_mode_version
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typedef struct ofb_buf {
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byte* s_register;
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byte* enc_s_register;
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int blocksize;
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} OFB_BUFFER;
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/* OFB MODE */
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int _init_mcrypt( OFB_BUFFER* buf, void *key, int lenofkey, void *IV, int size)
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{
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buf->s_register = buf->enc_s_register = NULL;
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buf->blocksize = size;
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/* For ofb */
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buf->s_register=malloc( size);
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if (buf->s_register==NULL) goto freeall;
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buf->enc_s_register=malloc( size);
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if (buf->enc_s_register==NULL) goto freeall;
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if (IV!=NULL) {
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memcpy(buf->s_register, IV, size);
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} else {
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memset(buf->s_register, 0, size);
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}
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/* End ofb */
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return 0;
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freeall:
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free(buf->s_register);
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free(buf->enc_s_register);
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return -1;
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}
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int _mcrypt_get_state( OFB_BUFFER* buf, byte *IV, int *size)
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{
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if (*size < buf->blocksize) {
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*size = buf->blocksize;
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return -1;
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}
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*size = buf->blocksize;
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memcpy( IV, buf->s_register, buf->blocksize);
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return 0;
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}
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int _mcrypt_set_state( OFB_BUFFER* buf, void *IV, int size)
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{
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memcpy(buf->enc_s_register, IV, size);
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memcpy(buf->s_register, IV, size);
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return 0;
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}
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void _end_mcrypt( OFB_BUFFER* buf) {
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free(buf->s_register);
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free(buf->enc_s_register);
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}
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int _mcrypt( OFB_BUFFER* buf,void *plaintext, int len, int blocksize, void* akey, void (*func)(void*,void*), void (*func2)(void*,void*) )
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{ /* plaintext is 1 byte (8bit ofb) */
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char *plain = plaintext;
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int i, j;
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void (*_mcrypt_block_encrypt) (void *, void *);
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_mcrypt_block_encrypt = func;
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for (j = 0; j < len; j++) {
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memcpy(buf->enc_s_register, buf->s_register, blocksize);
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_mcrypt_block_encrypt(akey, buf->enc_s_register);
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plain[j] ^= buf->enc_s_register[0];
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/* Shift the register */
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for (i = 0; i < (blocksize - 1); i++)
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buf->s_register[i] = buf->s_register[i + 1];
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buf->s_register[blocksize - 1] = buf->enc_s_register[0];
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}
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return 0;
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}
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int _mdecrypt( OFB_BUFFER* buf, void *plaintext, int len, int blocksize, void* akey, void (*func)(void*,void*), void (*func2)(void*,void*))
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{ /* plaintext is 1 byte (8bit ofb) */
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char *plain = plaintext;
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int i, j;
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void (*_mcrypt_block_encrypt) (void *, void *);
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_mcrypt_block_encrypt = func;
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for (j = 0; j < len; j++) {
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memcpy(buf->enc_s_register, buf->s_register, blocksize);
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_mcrypt_block_encrypt(akey, buf->enc_s_register);
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/* Shift the register */
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for (i = 0; i < (blocksize - 1); i++)
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buf->s_register[i] = buf->s_register[i + 1];
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buf->s_register[blocksize - 1] = buf->enc_s_register[0];
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plain[j] ^= buf->enc_s_register[0];
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}
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return 0;
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}
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int _is_block_mode() { return 0; }
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int _has_iv() { return 1; }
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int _is_block_algorithm_mode() { return 1; }
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char *_mcrypt_get_modes_name() { return "OFB"; }
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int _mcrypt_mode_get_size () {return sizeof(OFB_BUFFER);}
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word32 _mcrypt_mode_version() {
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return 20010310;
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}
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#ifdef WIN32
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# ifdef USE_LTDL
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WIN32DLL_DEFINE int main (void)
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{
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/* empty main function to avoid linker error (see cygwin FAQ) */
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}
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# endif
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#endif
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