wStream* license_send_stream_init(rdpLicense* license)
{
wStream* s;
BOOL do_crypt = license->rdp->do_crypt;
license->rdp->sec_flags = SEC_LICENSE_PKT;
/**
* Encryption of licensing packets is optional even if the rdp security
* layer is used. If the peer has not indicated that it is capable of
* processing encrypted licensing packets (rdp->do_crypt_license) we turn
* off encryption (via rdp->do_crypt) before initializing the rdp stream
* and reenable it afterwards.
*/
if (do_crypt)
{
license->rdp->sec_flags |= SEC_LICENSE_ENCRYPT_CS;
license->rdp->do_crypt = license->rdp->do_crypt_license;
}
s = transport_send_stream_init(license->rdp->transport, 4096);
if (!s)
return NULL;
rdp_init_stream(license->rdp, s);
license->rdp->do_crypt = do_crypt;
license->PacketHeaderLength = Stream_GetPosition(s);
Stream_Seek(s, LICENSE_PREAMBLE_LENGTH);
return s;
}
STREAM* rdp_send_stream_init(rdpRdp* rdp)
{
STREAM* s;
s = transport_send_stream_init(rdp->transport, 2048);
stream_seek(s, RDP_PACKET_HEADER_LENGTH);
return s;
}
wStream* rdp_data_pdu_init(rdpRdp* rdp)
{
wStream* s;
s = transport_send_stream_init(rdp->transport, 2048);
rdp_init_stream_data_pdu(rdp, s);
return s;
}
STREAM* license_send_stream_init(rdpLicense* license)
{
STREAM* s;
s = transport_send_stream_init(license->rdp->transport, 4096);
stream_seek(s, LICENSE_PACKET_HEADER_MAX_LENGTH);
return s;
}
wStream* rdp_message_channel_pdu_init(rdpRdp* rdp)
{
wStream* s;
s = transport_send_stream_init(rdp->transport, 2048);
Stream_Seek(s, RDP_PACKET_HEADER_MAX_LENGTH);
rdp_security_stream_init(rdp, s);
return s;
}
STREAM* rdp_pdu_init(rdpRdp* rdp)
{
STREAM* s;
s = transport_send_stream_init(rdp->transport, 2048);
stream_seek(s, RDP_PACKET_HEADER_MAX_LENGTH);
rdp_security_stream_init(rdp, s);
stream_seek(s, RDP_SHARE_CONTROL_HEADER_LENGTH);
return s;
}
STREAM* rdp_data_pdu_init(rdpRdp* rdp)
{
STREAM* s;
s = transport_send_stream_init(rdp->transport, 2048);
stream_seek(s, RDP_PACKET_HEADER_LENGTH);
stream_seek(s, RDP_SHARE_CONTROL_HEADER_LENGTH);
stream_seek(s, RDP_SHARE_DATA_HEADER_LENGTH);
return s;
}
BOOL nego_send_negotiation_request(rdpNego* nego)
{
STREAM* s;
int length;
BYTE *bm, *em;
int cookie_length;
s = transport_send_stream_init(nego->transport, 256);
length = TPDU_CONNECTION_REQUEST_LENGTH;
stream_get_mark(s, bm);
stream_seek(s, length);
if (nego->RoutingToken != NULL)
{
stream_write(s, nego->RoutingToken, nego->RoutingTokenLength);
length += nego->RoutingTokenLength;
}
else if (nego->cookie != NULL)
{
cookie_length = strlen(nego->cookie);
if (cookie_length > (int) nego->cookie_max_length)
cookie_length = nego->cookie_max_length;
stream_write(s, "Cookie: mstshash=", 17);
stream_write(s, (BYTE*) nego->cookie, cookie_length);
stream_write_BYTE(s, 0x0D); /* CR */
stream_write_BYTE(s, 0x0A); /* LF */
length += cookie_length + 19;
}
DEBUG_NEGO("requested_protocols: %d", nego->requested_protocols);
if (nego->requested_protocols > PROTOCOL_RDP)
{
/* RDP_NEG_DATA must be present for TLS and NLA */
stream_write_BYTE(s, TYPE_RDP_NEG_REQ);
stream_write_BYTE(s, 0); /* flags, must be set to zero */
stream_write_UINT16(s, 8); /* RDP_NEG_DATA length (8) */
stream_write_UINT32(s, nego->requested_protocols); /* requestedProtocols */
length += 8;
}
stream_get_mark(s, em);
stream_set_mark(s, bm);
tpkt_write_header(s, length);
tpdu_write_connection_request(s, length - 5);
stream_set_mark(s, em);
if (transport_write(nego->transport, s) < 0)
return FALSE;
return TRUE;
}
boolean nego_send_negotiation_request(rdpNego* nego)
{
STREAM* s;
int length;
uint8 *bm, *em;
s = transport_send_stream_init(nego->transport, 256);
length = TPDU_CONNECTION_REQUEST_LENGTH;
stream_get_mark(s, bm);
stream_seek(s, length);
if (nego->routing_token != NULL)
{
stream_write(s, nego->routing_token->data, nego->routing_token->length);
length += nego->routing_token->length;
}
else if (nego->cookie != NULL)
{
int cookie_length = strlen(nego->cookie);
stream_write(s, "Cookie: mstshash=", 17);
stream_write(s, (uint8*) nego->cookie, cookie_length);
stream_write_uint8(s, 0x0D); /* CR */
stream_write_uint8(s, 0x0A); /* LF */
length += cookie_length + 19;
}
DEBUG_NEGO("requested_protocols: %d", nego->requested_protocols);
if (nego->requested_protocols > PROTOCOL_RDP)
{
/* RDP_NEG_DATA must be present for TLS and NLA */
stream_write_uint8(s, TYPE_RDP_NEG_REQ);
stream_write_uint8(s, 0); /* flags, must be set to zero */
stream_write_uint16(s, 8); /* RDP_NEG_DATA length (8) */
stream_write_uint32(s, nego->requested_protocols); /* requestedProtocols */
length += 8;
}
stream_get_mark(s, em);
stream_set_mark(s, bm);
tpkt_write_header(s, length);
tpdu_write_connection_request(s, length - 5);
stream_set_mark(s, em);
if (transport_write(nego->transport, s) < 0)
return false;
return true;
}
boolean nego_send_preconnection_pdu(rdpNego* nego)
{
STREAM* s;
uint32 cbSize;
UNICONV* uniconv;
uint16 cchPCB_times2 = 0;
char* wszPCB = NULL;
if (!nego->send_preconnection_pdu)
return true;
DEBUG_NEGO("Sending preconnection PDU");
if (!nego_tcp_connect(nego))
return false;
/* it's easier to always send the version 2 PDU, and it's just 2 bytes overhead */
cbSize = PRECONNECTION_PDU_V2_MIN_SIZE;
if (nego->preconnection_blob)
{
size_t size;
uniconv = freerdp_uniconv_new();
wszPCB = freerdp_uniconv_out(uniconv, nego->preconnection_blob, &size);
cchPCB_times2 = (uint16) size;
freerdp_uniconv_free(uniconv);
cchPCB_times2 += 2; /* zero-termination */
cbSize += cchPCB_times2;
}
s = transport_send_stream_init(nego->transport, cbSize);
stream_write_uint32(s, cbSize); /* cbSize */
stream_write_uint32(s, 0); /* Flags */
stream_write_uint32(s, PRECONNECTION_PDU_V2); /* Version */
stream_write_uint32(s, nego->preconnection_id); /* Id */
stream_write_uint16(s, cchPCB_times2 / 2); /* cchPCB */
if (wszPCB)
{
stream_write(s, wszPCB, cchPCB_times2); /* wszPCB */
xfree(wszPCB);
}
if (transport_write(nego->transport, s) < 0)
return false;
return true;
}
wStream* license_send_stream_init(rdpLicense* license)
{
wStream* s;
license->rdp->sec_flags = SEC_LICENSE_PKT;
if (license->rdp->do_crypt)
license->rdp->sec_flags |= SEC_LICENSE_ENCRYPT_CS;
s = transport_send_stream_init(license->rdp->transport, 4096);
rdp_init_stream(license->rdp, s);
license->PacketHeaderLength = Stream_GetPosition(s);
Stream_Seek(s, LICENSE_PREAMBLE_LENGTH);
return s;
}
BOOL nego_send_preconnection_pdu(rdpNego* nego)
{
STREAM* s;
UINT32 cbSize;
UINT16 cchPCB = 0;
WCHAR* wszPCB = NULL;
if (!nego->send_preconnection_pdu)
return TRUE;
DEBUG_NEGO("Sending preconnection PDU");
if (!nego_tcp_connect(nego))
return FALSE;
/* it's easier to always send the version 2 PDU, and it's just 2 bytes overhead */
cbSize = PRECONNECTION_PDU_V2_MIN_SIZE;
if (nego->preconnection_blob)
{
cchPCB = (UINT16) ConvertToUnicode(CP_UTF8, 0, nego->preconnection_blob, -1, &wszPCB, 0);
cchPCB += 1; /* zero-termination */
cbSize += cchPCB * 2;
}
s = transport_send_stream_init(nego->transport, cbSize);
stream_write_UINT32(s, cbSize); /* cbSize */
stream_write_UINT32(s, 0); /* Flags */
stream_write_UINT32(s, PRECONNECTION_PDU_V2); /* Version */
stream_write_UINT32(s, nego->preconnection_id); /* Id */
stream_write_UINT16(s, cchPCB); /* cchPCB */
if (wszPCB)
{
stream_write(s, wszPCB, cchPCB * 2); /* wszPCB */
free(wszPCB);
}
if (transport_write(nego->transport, s) < 0)
return FALSE;
return TRUE;
}
boolean nego_send_negotiation_response(rdpNego* nego)
{
STREAM* s;
int length;
uint8 *bm, *em;
s = transport_send_stream_init(nego->transport, 256);
length = TPDU_CONNECTION_CONFIRM_LENGTH;
stream_get_mark(s, bm);
stream_seek(s, length);
if (nego->selected_protocol > PROTOCOL_RDP)
{
/* RDP_NEG_DATA must be present for TLS and NLA */
stream_write_uint8(s, TYPE_RDP_NEG_RSP);
stream_write_uint8(s, EXTENDED_CLIENT_DATA_SUPPORTED); /* flags */
stream_write_uint16(s, 8); /* RDP_NEG_DATA length (8) */
stream_write_uint32(s, nego->selected_protocol); /* selectedProtocol */
length += 8;
}
stream_get_mark(s, em);
stream_set_mark(s, bm);
tpkt_write_header(s, length);
tpdu_write_connection_confirm(s, length - 5);
stream_set_mark(s, em);
if (transport_write(nego->transport, s) < 0)
return false;
/* update settings with negotiated protocol security */
nego->transport->settings->requested_protocols = nego->requested_protocols;
nego->transport->settings->selected_protocol = nego->selected_protocol;
return true;
}
boolean nego_send_negotiation_response(rdpNego* nego)
{
STREAM* s;
uint8* bm;
uint8* em;
int length;
boolean status;
rdpSettings* settings;
status = true;
settings = nego->transport->settings;
s = transport_send_stream_init(nego->transport, 256);
length = TPDU_CONNECTION_CONFIRM_LENGTH;
stream_get_mark(s, bm);
stream_seek(s, length);
if (nego->selected_protocol > PROTOCOL_RDP)
{
/* RDP_NEG_DATA must be present for TLS and NLA */
stream_write_uint8(s, TYPE_RDP_NEG_RSP);
stream_write_uint8(s, EXTENDED_CLIENT_DATA_SUPPORTED); /* flags */
stream_write_uint16(s, 8); /* RDP_NEG_DATA length (8) */
stream_write_uint32(s, nego->selected_protocol); /* selectedProtocol */
length += 8;
}
else if (!settings->rdp_security)
{
stream_write_uint8(s, TYPE_RDP_NEG_FAILURE);
stream_write_uint8(s, 0); /* flags */
stream_write_uint16(s, 8); /* RDP_NEG_DATA length (8) */
/*
* TODO: Check for other possibilities,
* like SSL_NOT_ALLOWED_BY_SERVER.
*/
printf("nego_send_negotiation_response: client supports only Standard RDP Security\n");
stream_write_uint32(s, SSL_REQUIRED_BY_SERVER);
length += 8;
status = false;
}
stream_get_mark(s, em);
stream_set_mark(s, bm);
tpkt_write_header(s, length);
tpdu_write_connection_confirm(s, length - 5);
stream_set_mark(s, em);
if (transport_write(nego->transport, s) < 0)
return false;
if (status)
{
/* update settings with negotiated protocol security */
settings->requested_protocols = nego->requested_protocols;
settings->selected_protocol = nego->selected_protocol;
if (settings->selected_protocol == PROTOCOL_RDP)
{
settings->tls_security = false;
settings->nla_security = false;
settings->rdp_security = true;
if (!settings->local)
{
settings->encryption = true;
settings->encryption_method = ENCRYPTION_METHOD_40BIT | ENCRYPTION_METHOD_128BIT | ENCRYPTION_METHOD_FIPS;
settings->encryption_level = ENCRYPTION_LEVEL_CLIENT_COMPATIBLE;
}
if (settings->encryption && settings->server_key == NULL && settings->rdp_key_file == NULL)
return false;
}
else if (settings->selected_protocol == PROTOCOL_TLS)
{
settings->tls_security = true;
settings->nla_security = false;
settings->rdp_security = false;
settings->encryption = false;
settings->encryption_method = ENCRYPTION_METHOD_NONE;
settings->encryption_level = ENCRYPTION_LEVEL_NONE;
}
else if (settings->selected_protocol == PROTOCOL_NLA)
{
settings->tls_security = true;
settings->nla_security = true;
settings->rdp_security = false;
settings->encryption = false;
settings->encryption_method = ENCRYPTION_METHOD_NONE;
settings->encryption_level = ENCRYPTION_LEVEL_NONE;
}
}
return status;
}
static boolean rdp_establish_keys(rdpRdp* rdp)
{
uint8 client_random[32];
uint8 crypt_client_random[256 + 8];
uint32 key_len;
uint8* mod;
uint8* exp;
uint32 length;
STREAM* s;
if (rdp->settings->encryption == False)
{
/* no RDP encryption */
return True;
}
/* encrypt client random */
memset(crypt_client_random, 0, sizeof(crypt_client_random));
memset(client_random, 0x5e, 32);
crypto_nonce(client_random, 32);
key_len = rdp->settings->server_cert->cert_info.modulus.length;
mod = rdp->settings->server_cert->cert_info.modulus.data;
exp = rdp->settings->server_cert->cert_info.exponent;
crypto_rsa_encrypt(client_random, 32, key_len, mod, exp, crypt_client_random);
/* send crypt client random to server */
length = 7 + 8 + 4 + 4 + key_len + 8;
s = transport_send_stream_init(rdp->mcs->transport, length);
tpkt_write_header(s, length);
tpdu_write_header(s, 2, 0xf0);
per_write_choice(s, DomainMCSPDU_SendDataRequest << 2);
per_write_integer16(s, rdp->mcs->user_id, MCS_BASE_CHANNEL_ID);
per_write_integer16(s, MCS_GLOBAL_CHANNEL_ID, 0);
stream_write_uint8(s, 0x70);
length = (4 + 4 + key_len + 8) | 0x8000;
stream_write_uint16_be(s, length);
stream_write_uint32(s, 1); /* SEC_CLIENT_RANDOM */
length = key_len + 8;
stream_write_uint32(s, length);
memcpy(s->p, crypt_client_random, length);
stream_seek(s, length);
if (transport_write(rdp->mcs->transport, s) < 0)
{
return False;
}
/* now calculate encrypt / decrypt and update keys */
if (!security_establish_keys(client_random, rdp))
{
return False;
}
rdp->do_crypt = True;
if (rdp->settings->encryption_method == ENCRYPTION_METHOD_FIPS)
{
uint8 fips_ivec[8] = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
rdp->fips_encrypt = crypto_des3_encrypt_init(rdp->fips_encrypt_key, fips_ivec);
rdp->fips_decrypt = crypto_des3_decrypt_init(rdp->fips_decrypt_key, fips_ivec);
rdp->fips_hmac = crypto_hmac_new();
return True;
}
rdp->rc4_decrypt_key = crypto_rc4_init(rdp->decrypt_key, rdp->rc4_key_len);
rdp->rc4_encrypt_key = crypto_rc4_init(rdp->encrypt_key, rdp->rc4_key_len);
return True;
}
BOOL nego_send_negotiation_response(rdpNego* nego)
{
STREAM* s;
BYTE* bm;
BYTE* em;
int length;
BOOL status;
rdpSettings* settings;
status = TRUE;
settings = nego->transport->settings;
s = transport_send_stream_init(nego->transport, 256);
length = TPDU_CONNECTION_CONFIRM_LENGTH;
stream_get_mark(s, bm);
stream_seek(s, length);
if (nego->selected_protocol > PROTOCOL_RDP)
{
/* RDP_NEG_DATA must be present for TLS and NLA */
stream_write_BYTE(s, TYPE_RDP_NEG_RSP);
stream_write_BYTE(s, EXTENDED_CLIENT_DATA_SUPPORTED); /* flags */
stream_write_UINT16(s, 8); /* RDP_NEG_DATA length (8) */
stream_write_UINT32(s, nego->selected_protocol); /* selectedProtocol */
length += 8;
}
else if (!settings->RdpSecurity)
{
stream_write_BYTE(s, TYPE_RDP_NEG_FAILURE);
stream_write_BYTE(s, 0); /* flags */
stream_write_UINT16(s, 8); /* RDP_NEG_DATA length (8) */
/*
* TODO: Check for other possibilities,
* like SSL_NOT_ALLOWED_BY_SERVER.
*/
printf("nego_send_negotiation_response: client supports only Standard RDP Security\n");
stream_write_UINT32(s, SSL_REQUIRED_BY_SERVER);
length += 8;
status = FALSE;
}
stream_get_mark(s, em);
stream_set_mark(s, bm);
tpkt_write_header(s, length);
tpdu_write_connection_confirm(s, length - 5);
stream_set_mark(s, em);
if (transport_write(nego->transport, s) < 0)
return FALSE;
if (status)
{
/* update settings with negotiated protocol security */
settings->RequestedProtocols = nego->requested_protocols;
settings->SelectedProtocol = nego->selected_protocol;
if (settings->SelectedProtocol == PROTOCOL_RDP)
{
settings->TlsSecurity = FALSE;
settings->NlaSecurity = FALSE;
settings->RdpSecurity = TRUE;
if (!settings->LocalConnection)
{
settings->DisableEncryption = TRUE;
settings->EncryptionMethods = ENCRYPTION_METHOD_40BIT | ENCRYPTION_METHOD_128BIT | ENCRYPTION_METHOD_FIPS;
settings->EncryptionLevel = ENCRYPTION_LEVEL_CLIENT_COMPATIBLE;
}
if (settings->DisableEncryption && settings->RdpServerRsaKey == NULL && settings->RdpKeyFile == NULL)
return FALSE;
}
else if (settings->SelectedProtocol == PROTOCOL_TLS)
{
settings->TlsSecurity = TRUE;
settings->NlaSecurity = FALSE;
settings->RdpSecurity = FALSE;
settings->DisableEncryption = FALSE;
settings->EncryptionMethods = ENCRYPTION_METHOD_NONE;
settings->EncryptionLevel = ENCRYPTION_LEVEL_NONE;
}
else if (settings->SelectedProtocol == PROTOCOL_NLA)
{
settings->TlsSecurity = TRUE;
settings->NlaSecurity = TRUE;
settings->RdpSecurity = FALSE;
settings->DisableEncryption = FALSE;
settings->EncryptionMethods = ENCRYPTION_METHOD_NONE;
settings->EncryptionLevel = ENCRYPTION_LEVEL_NONE;
}
}
return status;
}
static boolean rdp_client_establish_keys(rdpRdp* rdp)
{
uint8 client_random[CLIENT_RANDOM_LENGTH];
uint8 crypt_client_random[256 + 8];
uint32 key_len;
uint8* mod;
uint8* exp;
uint32 length;
STREAM* s;
if (rdp->settings->encryption == false)
{
/* no RDP encryption */
return true;
}
/* encrypt client random */
memset(crypt_client_random, 0, sizeof(crypt_client_random));
crypto_nonce(client_random, sizeof(client_random));
key_len = rdp->settings->server_cert->cert_info.modulus.length;
mod = rdp->settings->server_cert->cert_info.modulus.data;
exp = rdp->settings->server_cert->cert_info.exponent;
crypto_rsa_public_encrypt(client_random, sizeof(client_random), key_len, mod, exp, crypt_client_random);
/* send crypt client random to server */
length = RDP_PACKET_HEADER_MAX_LENGTH + RDP_SECURITY_HEADER_LENGTH + 4 + key_len + 8;
s = transport_send_stream_init(rdp->mcs->transport, length);
rdp_write_header(rdp, s, length, MCS_GLOBAL_CHANNEL_ID);
rdp_write_security_header(s, SEC_EXCHANGE_PKT);
length = key_len + 8;
stream_write_uint32(s, length);
stream_write(s, crypt_client_random, length);
if (transport_write(rdp->mcs->transport, s) < 0)
{
return false;
}
/* now calculate encrypt / decrypt and update keys */
if (!security_establish_keys(client_random, rdp))
{
return false;
}
rdp->do_crypt = true;
if (rdp->settings->salted_checksum)
rdp->do_secure_checksum = true;
if (rdp->settings->encryption_method == ENCRYPTION_METHOD_FIPS)
{
uint8 fips_ivec[8] = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
rdp->fips_encrypt = crypto_des3_encrypt_init(rdp->fips_encrypt_key, fips_ivec);
rdp->fips_decrypt = crypto_des3_decrypt_init(rdp->fips_decrypt_key, fips_ivec);
rdp->fips_hmac = crypto_hmac_new();
return true;
}
rdp->rc4_decrypt_key = crypto_rc4_init(rdp->decrypt_key, rdp->rc4_key_len);
rdp->rc4_encrypt_key = crypto_rc4_init(rdp->encrypt_key, rdp->rc4_key_len);
return true;
}
