/*
cipher.c -- Symmetric block cipher handling
- Copyright (C) 2007 Guus Sliepen <guus@tinc-vpn.org>
+ Copyright (C) 2007-2012 Guus Sliepen <guus@tinc-vpn.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
void cipher_close(cipher_t *cipher) {
EVP_CIPHER_CTX_cleanup(&cipher->ctx);
- if(cipher->counter) {
- free(cipher->counter);
- cipher->counter = 0;
- }
+ free(cipher->counter);
+ cipher->counter = NULL;
}
size_t cipher_keylength(const cipher_t *cipher) {
return false;
}
+bool cipher_set_counter(cipher_t *cipher, const void *counter, size_t len) {
+ if(len > cipher->cipher->block_size - 4) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Counter too long");
+ abort();
+ }
+
+ memcpy(cipher->counter->counter + cipher->cipher->block_size - len, counter, len);
+ memset(cipher->counter->counter, 0, 4);
+ cipher->counter->n = 0;
+
+ return true;
+}
+
bool cipher_set_counter_key(cipher_t *cipher, void *key) {
int result = EVP_EncryptInit_ex(&cipher->ctx, cipher->cipher, NULL, (unsigned char *)key, NULL);
if(!result) {
unsigned char *out = outdata;
while(inlen--) {
- // Encrypt the new counter value if we need it
+ // Encrypt the new counter value if we need it
if(!cipher->counter->n) {
int len;
if(!EVP_EncryptUpdate(&cipher->ctx, cipher->counter->block, &len, cipher->counter->counter, cipher->cipher->block_size)) {