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libsxmp/sxt/lcrypt.c

174 lines
4.4 KiB
C

/*
* Secure eXtended Message Passing framework
* Secure eXtended Transport layer implementation: (libsxt)
* - very similar to SSH2/TLS
* - using already proven and tested crypto algos
* - better than TLS for message passing
*
* libressl/openssl wrappers
*
* (c) Alexander Vdolainen 2016 <avdolainen@zoho.com>
*
* libsxmp is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* libsxmp 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.";
*
*/
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/aes.h>
#include <openssl/blowfish.h>
#include <sxt/errno.h>
#include <sxt/ciphers.h>
#include <sxt/lcrypt.h>
/* internals */
static int __alloc_keybuf(sxt_cipher_t *c)
{
if(!c->lcp) return -1;
if(!(c->lcp->key = malloc(c->keylen))) return -1;
return 0;
}
void lcrypt_cleanup_keystub(sxt_cipher_t *c)
{
if(!c || !c->lcp) return;
memset(c->lcp->key, 0, sizeof(c->keylen));
free(c->lcp->key);
memset(c->lcp, 0, sizeof(struct _lcrypt_cipher_priv));
free(c->lcp);
return;
}
int lcrypt_alloc_keystub(sxt_cipher_t *c)
{
if(!c) return -1;
if(!(c->lcp = malloc(sizeof(struct _lcrypt_cipher_priv)))) return -1;
else memset(c->lcp, 0, sizeof(struct _lcrypt_cipher_priv));
return 0;
}
/* AES */
static int aes_set_encrypt_key(sxt_cipher_t *cipher, void *key, void *ivec)
{
if (cipher->lcp->key == NULL) {
if (__alloc_keybuf(cipher) < 0) return -1;
if(AES_set_encrypt_key(key, cipher->keysize, cipher->lcp->key) < 0) {
if(cipher->lcp->key) {
memset(cipher->lcp->key, 0, cipher->keylen);
free(cipher->lcp->key);
cipher->lcp->key = NULL;
}
return -1;
}
}
cipher->lcp->ivec = ivec;
return 0;
}
static int aes_set_decrypt_key(sxt_cipher_t *cipher, void *key, void *ivec)
{
if (cipher->lcp->key == NULL) {
if (__alloc_keybuf(cipher) < 0) return -1;
if (AES_set_decrypt_key(key, cipher->keysize, cipher->lcp->key) < 0) {
if(cipher->lcp->key) {
memset(cipher->lcp->key, 0, cipher->keylen);
free(cipher->lcp->key);
cipher->lcp->key = NULL;
}
return -1;
}
}
cipher->lcp->ivec = ivec;
return 0;
}
static void aes_encrypt(sxt_cipher_t *cipher, void *in, void *out,
unsigned long len)
{
AES_cbc_encrypt(in, out, len, cipher->lcp->key, cipher->lcp->ivec, AES_ENCRYPT);
}
static void aes_decrypt(sxt_cipher_t *cipher, void *in, void *out,
unsigned long len)
{
AES_cbc_encrypt(in, out, len, cipher->lcp->key, cipher->lcp->ivec, AES_DECRYPT);
}
static struct _cipher_ops aes_ops = {
.set_encrypt_key = aes_set_encrypt_key,
.set_decrypt_key = aes_set_decrypt_key,
.encrypt = aes_encrypt,
.decrypt = aes_decrypt,
};
/* blow fish */
static int blowfish_set_key(sxt_cipher_t *cipher, void *key, void *ivec)
{
if (cipher->lcp->key == NULL) {
if (__alloc_keybuf(cipher) < 0) return -1;
BF_set_key(cipher->lcp->key, 16, key);
}
cipher->lcp->ivec = ivec;
return 0;
}
static void blowfish_encrypt(sxt_cipher_t *cipher, void *in,
void *out, unsigned long len)
{
BF_cbc_encrypt(in, out, len, cipher->lcp->key, cipher->lcp->ivec, BF_ENCRYPT);
}
static void blowfish_decrypt(sxt_cipher_t *cipher, void *in,
void *out, unsigned long len)
{
BF_cbc_encrypt(in, out, len, cipher->lcp->key, cipher->lcp->ivec, BF_DECRYPT);
}
static struct _cipher_ops bf_ops = {
.set_encrypt_key = blowfish_set_key,
.set_decrypt_key = blowfish_set_key,
.encrypt = blowfish_encrypt,
.decrypt = blowfish_decrypt,
};
int lcrypt_init_ciphers(void)
{
int r = 0;
r = sxt_cipher_add("blowfish-cbc", 8, sizeof(BF_KEY), 128, &bf_ops);
r = sxt_cipher_add("aes128-cbc", 16, sizeof(AES_KEY), 128, &aes_ops);
r = sxt_cipher_add("aes192-cbc", 16, sizeof(AES_KEY), 192, &aes_ops);
r = sxt_cipher_add("aes256-cbc", 16, sizeof(AES_KEY), 256, &aes_ops);
return r;
}