/*

* Lessfs: A data deduplicating filesystem.

* Copyright (C) 2008 Mark Ruijter <mruijter@lessfs.com>

*

* This program is free software.

* You can redistribute lessfs and/or modify it under the terms of either

* (1) the GNU General Public License; either version 3 of the License,

* or (at your option) any later version as published by

* the Free Software Foundation; or (2) obtain a commercial license

* by contacting the Author.

*

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See

* the GNU General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program; if not, write to the Free Software

* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

*/

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#ifndef LFATAL

#include "lib_log.h"

#endif

#include<stdio.h>

#include<stdlib.h>

#include <string.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#ifdef ENABLE_CRYPTO

#include<openssl/ssl.h>

#include<openssl/evp.h>

#endif

#include "lib_safe.h"

#include "retcodes.h"

#include "lib_cfg.h"

extern char *logname;

extern char *function;

extern int debug;

extern int BLKSIZE;

extern char *passwd;

#define die_cryptoerr(f...) { LFATAL(f); exit(EXIT_CRYPTOERR); }

typedef struct {

unsigned long size;

unsigned char *data;

} DBT;

unsigned char *safepassword()

{

int len;

unsigned char *safepasswd;

len = strlen((char *) config->passwd);

if (len > 16)

len = 16;

safepasswd = s_malloc(16);

memset(safepasswd, 65, 16);

memcpy(safepasswd, config->passwd, len);

return safepasswd;

}

#ifdef ENABLE_CRYPTO

DBT *encrypt(unsigned char *unenc, unsigned long size)

{

unsigned char *safepasswd;

EVP_CIPHER_CTX ctx;

DBT *encoded;

int olen, tlen;

FUNC;

safepasswd = safepassword();

EVP_CIPHER_CTX_init(&ctx);

EVP_EncryptInit(&ctx, EVP_bf_cbc(), safepasswd, config->iv);

encoded = s_malloc(sizeof(DBT));

encoded->data = s_malloc(8 + size); //Blowfish can grow 64 bits

if (EVP_EncryptUpdate(&ctx, encoded->data, &olen, unenc, size) != 1) {

die_cryptoerr("error in encrypt update\n");

}

if (EVP_EncryptFinal(&ctx, encoded->data + olen, &tlen) != 1) {

die_cryptoerr("error in encrypt final\n");

}

EVP_CIPHER_CTX_cleanup(&ctx);

encoded->size = olen + tlen;

if (encoded->size > 8 + size) {

die_cryptoerr

("Unexpected fatal error : data has grown in size after encryption.\n");

}

free(safepasswd);

EFUNC;

return encoded;

}

DBT *decrypt(DBT * data)

{

DBT *decrypted;

unsigned char *safepasswd;

int olen, tlen;

FUNC;

decrypted = s_malloc(sizeof(DBT));

decrypted->data = s_malloc(data->size);

safepasswd = safepassword();

EVP_CIPHER_CTX ctx;

EVP_CIPHER_CTX_init(&ctx);

EVP_DecryptInit(&ctx, EVP_bf_cbc(), safepasswd, config->iv);

if (EVP_DecryptUpdate

(&ctx, decrypted->data, &olen, data->data, data->size) != 1) {

die_cryptoerr("Unexpected fatal error while decrypting.\n");

}

if (EVP_DecryptFinal(&ctx, decrypted->data + olen, &tlen) != 1) {

die_cryptoerr("Unexpected fatal error in decrypt final.\n");

}

olen += tlen;

EVP_CIPHER_CTX_cleanup(&ctx);

decrypted->size = olen;

free(safepasswd);

EFUNC;

return decrypted;

}

#endif