107 lines
2.8 KiB
C
107 lines
2.8 KiB
C
/*
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cipher.c -- wrapper functions for encryption algorithms
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Copyright (C) 1999 Ivo Timmermans <zarq@iname.com>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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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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This program 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
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include "config.h"
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#include <dlfcn.h>
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#include <string.h>
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#include <syslog.h>
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#include <cipher.h>
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#include "blowfish/blowfish.h"
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#include "idea/idea.h"
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#include "net.h"
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void (*blowfish_cfb64_encrypt) (unsigned char*, unsigned char*, int,
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BF_KEY*, unsigned char*, int*, int) = NULL;
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void (*blowfish_set_key) (BF_KEY*, int, char*) = NULL;
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unsigned char initvec[] = { 0x22, 0x7b, 0xad, 0x55, 0x41, 0xf4, 0x3e, 0xf3 };
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BF_KEY encryption_key;
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void low_crypt_key(unsigned char *in, unsigned char *out, BF_KEY *k, long len, int c)
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{
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int count = 7;
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unsigned char ivec[8];
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memcpy(ivec, initvec, 8);
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blowfish_cfb64_encrypt(in, out, len, k, &ivec[0], &count, c);
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}
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void do_encrypt(vpn_packet_t *in, real_packet_t *out, enc_key_t *key)
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{
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unsigned char ivec[8];
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int r;
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memcpy(ivec, initvec, 8);
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cipher_set_key(&encryption_key, key->length, key->key);
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low_crypt_key((char*)(&in->data), (char*)(&out->data.data),
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&encryption_key, in->len, BF_ENCRYPT);
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out->len = in->len + 2;
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r = (in->len + 2) % 8;
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if(r)
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out->len += (8-r);
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out->len += 8;
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/* The smallest multiple of 8 greater
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than or equal to in->len + 8 */
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out->data.len = in->len;
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}
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void do_decrypt(real_packet_t *in, vpn_packet_t *out, enc_key_t *key)
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{
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unsigned char ivec[8];
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memcpy(ivec, initvec, 8);
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cipher_set_key(&encryption_key, key->length, key->key);
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low_crypt_key((char*)(&in->data.data), (char*)(&out->data),
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&encryption_key, in->data.len, BF_DECRYPT);
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out->len = in->data.len;
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}
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void cipher_set_key(BF_KEY *k, int l, char *t)
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{
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blowfish_set_key(k, l, t);
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}
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int cipher_init(int which)
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{
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void *dlhandle;
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char *error;
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if((dlhandle = dlopen(PKGLIBDIR "libblowfish.so.0", RTLD_LAZY)) == NULL)
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{
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syslog(LOG_ERR, "%s: %m", PKGLIBDIR "libblowfish.so.0");
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return -1;
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}
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blowfish_cfb64_encrypt = dlsym(dlhandle, "BF_cfb64_encrypt");
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if((error = dlerror()) != NULL)
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{
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syslog(LOG_ERR, "%s", error);
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return -1;
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}
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blowfish_set_key = dlsym(dlhandle, "BF_set_key");
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return 0;
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}
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