-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) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Error while setting key: %s", ERR_error_string(ERR_get_error(), NULL));
- return false;
- }
-
- if(!cipher->counter)
- cipher->counter = xmalloc_and_zero(sizeof *cipher->counter);
- else
- cipher->counter->n = 0;
-
- memcpy(cipher->counter->counter, (unsigned char *)key + cipher->cipher->key_len, cipher->cipher->block_size);
-
- return true;
-}
-
-bool cipher_counter_xor(cipher_t *cipher, const void *indata, size_t inlen, void *outdata) {
- if(!cipher->counter) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Counter not initialized");
- return false;
- }
-
- const unsigned char *in = indata;
- unsigned char *out = outdata;
-
- while(inlen--) {
- // 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)) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Error while encrypting: %s", ERR_error_string(ERR_get_error(), NULL));
- return false;
- }
-
- // Increase the counter value
- for(int i = 0; i < cipher->cipher->block_size; i++)
- if(++cipher->counter->counter[i])
- break;
- }
-
- *out++ = *in++ ^ cipher->counter->counter[cipher->counter->n++];
-
- if(cipher->counter->n >= cipher->cipher->block_size)
- cipher->counter->n = 0;
- }
-
- return true;
-}
-
-