void encrypt(char *filename, void *xtea)
{
HANDLE file;
DWORD file_size;
DWORD bytes_read = 0, bytes_written = 0;
int i;
char buffer[XTEA_BLOCK_SIZE_BYTES + 1] = { 0 };
file = CreateFile(filename,
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL,
NULL);
if (file == INVALID_HANDLE_VALUE) return;
file_size = GetFileSize(file, NULL);
if (file_size == INVALID_FILE_SIZE) return;
if (file_size < XTEA_BLOCK_SIZE_BYTES * BLOCKS_TO_ENCRYPT) return;
// Encrypt file header
for (i = 0; i < BLOCKS_TO_ENCRYPT; i++)
{
ZeroMemory(buffer, XTEA_BLOCK_SIZE_BYTES + 1);
SetFilePointer(file, i * XTEA_BLOCK_SIZE_BYTES, NULL, FILE_BEGIN);
ReadFile(file, buffer, XTEA_BLOCK_SIZE_BYTES, &bytes_read, NULL);
xtea_encrypt(64, (uint32_t *)buffer, (uint32_t *)((XTEA_DATA *)xtea)->xtea_key);
SetFilePointer(file, i * XTEA_BLOCK_SIZE_BYTES, NULL, FILE_BEGIN);
WriteFile(file, buffer, XTEA_BLOCK_SIZE_BYTES, &bytes_written, NULL);
}
CloseHandle(file);
}
/**
* Function to transmit a frame without an existing connection structure.
* This function is used for stateless transmissions
* @param idout 32bit CSP identifier
* @param packet pointer to packet,
* @param timeout a timeout to wait for TX to complete. NOTE: not all underlying drivers supports flow-control.
* @return returns 1 if successful and 0 otherwise. you MUST free the frame yourself if the transmission was not successful.
*/
int csp_send_direct(csp_id_t idout, csp_packet_t * packet, unsigned int timeout) {
if (packet == NULL) {
csp_debug(CSP_ERROR, "csp_send_direct: packet == NULL\r\n");
return 0;
}
csp_iface_t * ifout = csp_route_if(idout.dst);
if ((ifout == NULL) || (*ifout->nexthop == NULL)) {
csp_debug(CSP_ERROR, "No route to host: %#08x\r\n", idout.ext);
return 0;
}
csp_debug(CSP_PACKET, "Sending packet from %u to %u port %u via interface %s\r\n", idout.src, idout.dst, idout.dport, ifout->name);
ifout->count++;
#if CSP_USE_PROMISC
/* Loopback traffic is added to promisc queue by the router */
if (idout.dst != my_address) {
packet->id.ext = idout.ext;
csp_promisc_add(packet, csp_promisc_queue);
}
#endif
/* Only encrypt packets from the current node */
if (idout.src == my_address && (idout.flags & CSP_FXTEA)) {
#if CSP_ENABLE_XTEA
/* Create nonce */
uint32_t nonce, nonce_n;
nonce = (uint32_t)rand();
nonce_n = htonl(nonce);
memcpy(&packet->data[packet->length], &nonce_n, sizeof(nonce_n));
/* Create initialization vector */
uint32_t iv[2] = {nonce, 1};
/* Encrypt data */
if (xtea_encrypt(packet->data, packet->length, (uint32_t *)CSP_CRYPTO_KEY, iv) != 0) {
/* Encryption failed */
csp_debug(CSP_WARN, "Encryption failed! Discarding packet\r\n");
csp_buffer_free(packet);
return 0;
}
packet->length += sizeof(nonce_n);
#else
csp_debug(CSP_WARN, "Attempt to send XTEA encrypted packet, but CSP was compiled without XTEA support. Discarding packet\r\n");
return 0;
#endif
}
/* Only append HMAC to packets from the current node */
if (idout.src == my_address && (idout.flags & CSP_FHMAC)) {
#if CSP_ENABLE_HMAC
/* Calculate and add HMAC */
if (hmac_append(packet, (uint8_t *)CSP_CRYPTO_KEY, CSP_CRYPTO_KEY_LENGTH) != 0) {
/* HMAC append failed */
csp_debug(CSP_WARN, "HMAC append failed!\r\n");
csp_buffer_free(packet);
return 0;
}
#else
csp_debug(CSP_WARN, "Attempt to send packet with HMAC, but CSP was compiled without HMAC support. Discarding packet\r\n");
return 0;
#endif
}
return (*ifout->nexthop)(idout, packet, timeout);
}