/*!
* @brief Transmit a packet via SSL _and_ destroy it.
* @param remote Pointer to the \c Remote instance.
* @param packet Pointer to the \c Packet that is to be sent.
* @param completion Pointer to the completion routines to process.
* @return An indication of the result of processing the transmission request.
* @remark This uses an SSL-encrypted TCP channel, and does not imply the use of HTTPS.
*/
DWORD packet_transmit_via_ssl(Remote* remote, Packet* packet, PacketRequestCompletion* completion)
{
CryptoContext* crypto;
Tlv requestId;
DWORD res;
DWORD idx;
TcpTransportContext* ctx = (TcpTransportContext*)remote->transport->ctx;
lock_acquire(remote->lock);
// If the packet does not already have a request identifier, create one for it
if (packet_get_tlv_string(packet, TLV_TYPE_REQUEST_ID, &requestId) != ERROR_SUCCESS)
{
DWORD index;
CHAR rid[32];
rid[sizeof(rid)-1] = 0;
for (index = 0; index < sizeof(rid)-1; index++)
{
rid[index] = (rand() % 0x5e) + 0x21;
}
packet_add_tlv_string(packet, TLV_TYPE_REQUEST_ID, rid);
}
do
{
// If a completion routine was supplied and the packet has a request
// identifier, insert the completion routine into the list
if ((completion) &&
(packet_get_tlv_string(packet, TLV_TYPE_REQUEST_ID,
&requestId) == ERROR_SUCCESS))
{
packet_add_completion_handler((LPCSTR)requestId.buffer, completion);
}
// If the endpoint has a cipher established and this is not a plaintext
// packet, we encrypt
if ((crypto = remote_get_cipher(remote)) &&
(packet_get_type(packet) != PACKET_TLV_TYPE_PLAIN_REQUEST) &&
(packet_get_type(packet) != PACKET_TLV_TYPE_PLAIN_RESPONSE))
{
ULONG origPayloadLength = packet->payloadLength;
PUCHAR origPayload = packet->payload;
// Encrypt
if ((res = crypto->handlers.encrypt(crypto, packet->payload,
packet->payloadLength, &packet->payload,
&packet->payloadLength)) !=
ERROR_SUCCESS)
{
SetLastError(res);
break;
}
// Destroy the original payload as we no longer need it
free(origPayload);
// Update the header length
packet->header.length = htonl(packet->payloadLength + sizeof(TlvHeader));
}
dprintf("[PACKET] New xor key for sending");
packet->header.xor_key = rand_xor_key();
// before transmission, xor the whole lot, starting with the body
xor_bytes(packet->header.xor_key, (LPBYTE)packet->payload, packet->payloadLength);
// then the header
xor_bytes(packet->header.xor_key, (LPBYTE)&packet->header.length, 8);
// be sure to switch the xor header before writing
packet->header.xor_key = htonl(packet->header.xor_key);
idx = 0;
while (idx < sizeof(packet->header))
{
// Transmit the packet's header (length, type)
res = SSL_write(
ctx->ssl,
(LPCSTR)(&packet->header) + idx,
sizeof(packet->header) - idx
);
if (res <= 0)
{
dprintf("[PACKET] transmit header failed with return %d at index %d\n", res, idx);
break;
}
idx += res;
}
if (res < 0)
{
break;
}
idx = 0;
while (idx < packet->payloadLength)
{
// Transmit the packet's payload (length, type)
res = SSL_write(
ctx->ssl,
packet->payload + idx,
packet->payloadLength - idx
);
if (res < 0)
{
break;
}
idx += res;
}
if (res < 0)
{
dprintf("[PACKET] transmit header failed with return %d at index %d\n", res, idx);
break;
}
SetLastError(ERROR_SUCCESS);
} while (0);
res = GetLastError();
// Destroy the packet
packet_destroy(packet);
lock_release(remote->lock);
return res;
}
/*
* Transmit and destroy a packet
*/
DWORD packet_transmit(Remote *remote, Packet *packet,
PacketRequestCompletion *completion)
{
CryptoContext *crypto;
Tlv requestId;
DWORD res;
DWORD idx;
#ifdef _UNIX
int local_error = -1;
#endif
// If the packet does not already have a request identifier, create
// one for it
if (packet_get_tlv_string(packet, TLV_TYPE_REQUEST_ID,
&requestId) != ERROR_SUCCESS)
{
DWORD index;
CHAR rid[32];
rid[sizeof(rid) - 1] = 0;
for (index = 0;
index < sizeof(rid) - 1;
index++)
rid[index] = (rand() % 0x5e) + 0x21;
packet_add_tlv_string(packet, TLV_TYPE_REQUEST_ID,
rid);
}
do
{
// If a completion routine was supplied and the packet has a request
// identifier, insert the completion routine into the list
if ((completion) &&
(packet_get_tlv_string(packet, TLV_TYPE_REQUEST_ID,
&requestId) == ERROR_SUCCESS))
packet_add_completion_handler((LPCSTR)requestId.buffer, completion);
// If the endpoint has a cipher established and this is not a plaintext
// packet, we encrypt
if ((crypto = remote_get_cipher(remote)) &&
(packet_get_type(packet) != PACKET_TLV_TYPE_PLAIN_REQUEST) &&
(packet_get_type(packet) != PACKET_TLV_TYPE_PLAIN_RESPONSE))
{
ULONG origPayloadLength = packet->payloadLength;
PUCHAR origPayload = packet->payload;
// Encrypt
if ((res = crypto->handlers.encrypt(crypto, packet->payload,
packet->payloadLength, &packet->payload,
&packet->payloadLength)) !=
ERROR_SUCCESS)
{
SetLastError(res);
break;
}
// Destroy the original payload as we no longer need it
free(origPayload);
// Update the header length
packet->header.length = htonl(packet->payloadLength + sizeof(TlvHeader));
}
idx = 0;
while( idx < sizeof(packet->header)) {
// Transmit the packet's header (length, type)
res = SSL_write(
remote->ssl,
(LPCSTR)(&packet->header) + idx,
sizeof(packet->header) - idx
);
if(res <= 0) {
dprintf("transmit header failed with return %d at index %d\n", res, idx);
break;
}
idx += res;
}
if(res < 0) break;
idx = 0;
while( idx < packet->payloadLength) {
// Transmit the packet's payload (length, type)
res = SSL_write(
remote->ssl,
packet->payload + idx,
packet->payloadLength - idx
);
if(res < 0)
break;
idx += res;
}
if(res < 0) {
dprintf("transmit header failed with return %d at index %d\n", res, idx);
break;
}
SetLastError(ERROR_SUCCESS);
} while (0);
res = GetLastError();
// Destroy the packet
packet_destroy(packet);
return res;
}
/*
* Transmit and destroy a packet over HTTP(S)
*/
DWORD packet_transmit_via_http(Remote *remote, Packet *packet, PacketRequestCompletion *completion)
{
CryptoContext *crypto;
Tlv requestId;
DWORD res;
#ifdef _UNIX
int local_error = -1;
#endif
lock_acquire( remote->lock );
// If the packet does not already have a request identifier, create one for it
if (packet_get_tlv_string(packet, TLV_TYPE_REQUEST_ID,&requestId) != ERROR_SUCCESS)
{
DWORD index;
CHAR rid[32];
rid[sizeof(rid) - 1] = 0;
for (index = 0; index < sizeof(rid) - 1; index++)
rid[index] = (rand() % 0x5e) + 0x21;
packet_add_tlv_string(packet, TLV_TYPE_REQUEST_ID, rid);
}
do
{
// If a completion routine was supplied and the packet has a request
// identifier, insert the completion routine into the list
if ((completion) &&
(packet_get_tlv_string(packet, TLV_TYPE_REQUEST_ID,
&requestId) == ERROR_SUCCESS))
packet_add_completion_handler((LPCSTR)requestId.buffer, completion);
// If the endpoint has a cipher established and this is not a plaintext
// packet, we encrypt
if ((crypto = remote_get_cipher(remote)) &&
(packet_get_type(packet) != PACKET_TLV_TYPE_PLAIN_REQUEST) &&
(packet_get_type(packet) != PACKET_TLV_TYPE_PLAIN_RESPONSE))
{
ULONG origPayloadLength = packet->payloadLength;
PUCHAR origPayload = packet->payload;
// Encrypt
if ((res = crypto->handlers.encrypt(crypto, packet->payload,
packet->payloadLength, &packet->payload,
&packet->payloadLength)) !=
ERROR_SUCCESS)
{
SetLastError(res);
break;
}
// Destroy the original payload as we no longer need it
free(origPayload);
// Update the header length
packet->header.length = htonl(packet->payloadLength + sizeof(TlvHeader));
}
#ifdef _WIN32
dprintf("Transmitting packet of length %d to remote", packet->payloadLength);
res = packet_transmit_via_http_wininet(remote, packet, completion);
#else
// XXX: Implement non-windows HTTP delivery
#endif
if(res < 0) {
dprintf("[PACKET] transmit failed with return %d\n", res);
break;
}
SetLastError(ERROR_SUCCESS);
} while (0);
res = GetLastError();
// Destroy the packet
packet_destroy(packet);
lock_release( remote->lock );
return res;
}
