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libxrdp: changes in rdp security layer negotiation

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This commit is contained in:
Idan Freiberg 2014-07-10 15:40:16 +03:00
parent 9007deae6f
commit 9795ce010a
3 changed files with 150 additions and 129 deletions
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2
libxrdp/libxrdp.h
View File

@ -42,8 +42,10 @@
struct xrdp_iso
{
struct xrdp_mcs *mcs_layer; /* owner */
int rdpNegData; /* bool */
int requestedProtocol;
int selectedProtocol;
int failureCode;
struct trans *trans;
};

269
libxrdp/xrdp_iso.c
View File

@ -1,8 +1,8 @@
/**
* xrdp: A Remote Desktop Protocol server.
*
* Copyright (C) Jay Sorg 2004-2013
* Copyright (C) Idan Freiberg 2013
* Copyright (C) Jay Sorg 2004-2014
* Copyright (C) Idan Freiberg 2013-2014
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
@ -22,13 +22,14 @@
#include "libxrdp.h"
/*****************************************************************************/
struct xrdp_iso *APP_CC
struct xrdp_iso *
APP_CC
xrdp_iso_create(struct xrdp_mcs *owner, struct trans *trans)
{
struct xrdp_iso *self;
DEBUG((" in xrdp_iso_create"));
self = (struct xrdp_iso *)g_malloc(sizeof(struct xrdp_iso), 1);
self = (struct xrdp_iso *) g_malloc(sizeof(struct xrdp_iso), 1);
self->mcs_layer = owner;
self->trans = trans;
DEBUG((" out xrdp_iso_create"));
@ -50,37 +51,36 @@ xrdp_iso_delete(struct xrdp_iso *self)
/*****************************************************************************/
/* returns error */
static int APP_CC
xrdp_iso_recv_rdpnegreq(struct xrdp_iso *self, struct stream *s)
xrdp_iso_process_rdpNegReq(struct xrdp_iso *self, struct stream *s)
{
int flags;
int len;
DEBUG((" in xrdp_iso_recv_rdpnegreq"));
DEBUG((" in xrdp_iso_process_neg_req"));
in_uint8(s, flags);
if (flags != 0x0 && flags != 0x8 && flags != 0x1)
{
DEBUG((" xrdp_iso_recv_rdpnegreq: flags: %x",flags));
DEBUG(("xrdp_iso_process_rdpNegReq: error, flags: %x",flags));
return 1;
}
in_uint16_le(s, len);
if (len != 8) // fixed length
if (len != 8)
{
DEBUG((" xrdp_iso_recv_rdpnegreq: length: %x",len));
DEBUG(("xrdp_iso_process_rdpNegReq: error, length: %x",len));
return 1;
}
in_uint32_le(s, self->requestedProtocol);
if (self->requestedProtocol > 0xb)
{
DEBUG(("xrdp_iso_process_rdpNegReq: error, requestedProtocol: %x",
self->requestedProtocol));
return 1;
}
//TODO: think of protocol verification logic
// if (requestedProtocol != PROTOCOL_RDP || PROTOCOL_SSL || PROTOCOL_HYBRID || PROTOCOL_HYBRID_EX)
// {
// DEBUG((" xrdp_iso_recv_rdpnegreq: wrong requestedProtocol: %x",requestedProtocol));
// return 1;
// }
DEBUG((" out xrdp_iso_recv_rdpnegreq"));
DEBUG((" out xrdp_iso_process_rdpNegReq"));
return 0;
}
/*****************************************************************************/
@ -88,11 +88,11 @@ xrdp_iso_recv_rdpnegreq(struct xrdp_iso *self, struct stream *s)
static int APP_CC
xrdp_iso_recv_msg(struct xrdp_iso *self, struct stream *s, int *code, int *len)
{
int ver; // TPKT Version
int plen; // TPKT PacketLength
int ver; // tpkt ver
int plen; // tpkt len
*code = 0; // X.224 Packet Type
*len = 0; // X.224 Length Indicator
*code = 0; // x.244 type
*len = 0; // X.224 len indicator
if (s != self->trans->in_s)
{
@ -169,120 +169,69 @@ xrdp_iso_recv(struct xrdp_iso *self, struct stream *s)
DEBUG((" out xrdp_iso_recv"));
return 0;
}
/*****************************************************************************/
static int APP_CC
xrdp_iso_send_rdpnegrsp(struct xrdp_iso *self, struct stream *s, int code)
{
init_stream(s, 8192 * 4); /* 32 KB */
/* TPKT HEADER - 4 bytes */
out_uint8(s, 3); /* version */
out_uint8(s, 0); /* RESERVED */
if (self->selectedProtocol != -1)
{
out_uint16_be(s, 19); /* length */ //rdp negotiation happens.
}
else
{
out_uint16_be(s, 11); /* length */ //rdp negotiation doesn't happen.
}
/* ISO LAYER - X.224 - 7 bytes*/
if (self->selectedProtocol != -1)
{
out_uint8(s, 14); /* length */
}
else
{
out_uint8(s, 6); /* length */
}
out_uint8(s, code); /* SHOULD BE 0xD for CC */
out_uint16_be(s, 0);
out_uint16_be(s, 0x1234);
out_uint8(s, 0);
if (self->selectedProtocol != -1)
{
/* RDP_NEG_RSP - 8 bytes*/
out_uint8(s, RDP_NEG_RSP);
out_uint8(s, EXTENDED_CLIENT_DATA_SUPPORTED); /* flags */
out_uint16_le(s, 8); /* fixed length */
out_uint32_le(s, self->selectedProtocol); /* selected protocol */
}
s_mark_end(s);
if (trans_force_write_s(self->trans, s) != 0)
{
return 1;
}
return 0;
}
/*****************************************************************************/
static int APP_CC
xrdp_iso_send_rdpnegfailure(struct xrdp_iso *self, struct stream *s, int code, int failureCode)
{
init_stream(s, 8192 * 4); /* 32 KB */
/* TPKT HEADER - 4 bytes */
out_uint8(s, 3); /* version */
out_uint8(s, 0); /* RESERVED */
out_uint16_be(s, 19); /* length */
/* ISO LAYER - X.224 - 7 bytes*/
out_uint8(s, 14); /* length */
out_uint8(s, code); /* SHOULD BE 0xD for CC */
out_uint16_be(s, 0);
out_uint16_be(s, 0x1234);
out_uint8(s, 0);
/* RDP_NEG_FAILURE - 8 bytes*/
out_uint8(s, RDP_NEG_FAILURE);
out_uint8(s, 0); /* no flags available */
out_uint16_le(s, 8); /* fixed length */
out_uint32_le(s, failureCode); /* failure code */
s_mark_end(s);
if (trans_force_write_s(self->trans, s) != 0)
{
return 1;
}
return 0;
}
/*****************************************************************************/
static int APP_CC
xrdp_iso_send_nego(struct xrdp_iso *self)
xrdp_iso_send_cc(struct xrdp_iso *self)
{
struct stream *s;
char *holdp;
char *len_ptr;
char *len_indicator_ptr;
int len;
int len_indicator;
make_stream(s);
init_stream(s, 8192);
//TODO: negotiation logic here.
if (self->requestedProtocol != PROTOCOL_RDP)
holdp = s->p;
/* tpkt */
out_uint8(s, 3); /* version */
out_uint8(s, 0); /* pad */
len_ptr = s->p;
out_uint16_be(s, 0); /* length, set later */
/* iso */
len_indicator_ptr = s->p;
out_uint8(s, 0); /* length indicator, set later */
out_uint8(s, ISO_PDU_CC); /* Connection Confirm PDU */
out_uint16_be(s, 0);
out_uint16_be(s, 0x1234);
out_uint8(s, 0);
/* rdpNegData */
if (self->rdpNegData)
{
// Send RDP_NEG_FAILURE back to client
if (xrdp_iso_send_rdpnegfailure(self, s, ISO_PDU_CC,
SSL_NOT_ALLOWED_BY_SERVER) != 0)
if (self->failureCode)
{
free_stream(s);
return 1;
out_uint8(s, RDP_NEG_FAILURE);
out_uint8(s, 0); /* no flags */
out_uint16_le(s, 8); /* must be 8 */
out_uint32_le(s, self->failureCode); /* failure code */
}
else
{
out_uint8(s, RDP_NEG_RSP);
//TODO: hardcoded flags
out_uint8(s, EXTENDED_CLIENT_DATA_SUPPORTED); /* flags */
out_uint16_le(s, 8); /* must be 8 */
out_uint32_le(s, self->selectedProtocol); /* selected protocol */
}
}
else
s_mark_end(s);
len = (int) (s->end - holdp);
len_indicator = (int) (s->end - len_indicator_ptr);
len_ptr[0] = len << 8;
len_ptr[1] = len;
len_indicator_ptr[0] = len_indicator;
if (trans_force_write_s(self->trans, s) != 0)
{
self->selectedProtocol = PROTOCOL_RDP;
// Send RDP_NEG_RSP back to client
if (xrdp_iso_send_rdpnegrsp(self, s, ISO_PDU_CC) != 0)
{
free_stream(s);
return 1;
}
return 1;
}
free_stream(s);
return 0;
}
/*****************************************************************************/
/* returns error */
int APP_CC
@ -306,7 +255,7 @@ xrdp_iso_incoming(struct xrdp_iso *self)
if (xrdp_iso_recv_msg(self, s, &code, &len) != 0)
{
DEBUG((" in xrdp_iso_recv_msg error!!"));
g_writeln("xrdp_iso_incoming: xrdp_iso_recv_msg returned non zero");
return 1;
}
@ -315,9 +264,7 @@ xrdp_iso_incoming(struct xrdp_iso *self)
return 1;
}
self->selectedProtocol = -1;
self->requestedProtocol = PROTOCOL_RDP;
/* process connection request */
pend = s->p + (len - 6);
cookie_index = 0;
while (s->p < pend)
@ -328,8 +275,11 @@ xrdp_iso_incoming(struct xrdp_iso *self)
default:
break;
case RDP_NEG_REQ: /* rdpNegReq 1 */
if (xrdp_iso_recv_rdpnegreq(self, s) != 0)
self->rdpNegData = 1;
if (xrdp_iso_process_rdpNegReq(self, s) != 0)
{
g_writeln(
"xrdp_iso_incoming: xrdp_iso_process_rdpNegReq returned non zero");
return 1;
}
break;
@ -355,8 +305,77 @@ xrdp_iso_incoming(struct xrdp_iso *self)
}
}
if (xrdp_iso_send_nego(self) != 0)
/* security layer negotiation */
if (self->rdpNegData)
{
int
serverSecurityLayer =
self->mcs_layer->sec_layer->rdp_layer->client_info.security_layer;
self->selectedProtocol = PROTOCOL_RDP; /* set default security layer */
switch (serverSecurityLayer)
{
case (PROTOCOL_SSL | PROTOCOL_HYBRID | PROTOCOL_HYBRID_EX):
/* server supports tls+hybrid+hybrid_ex */
if (self->requestedProtocol == (PROTOCOL_SSL | PROTOCOL_HYBRID
| PROTOCOL_HYBRID_EX))
{
/* client supports tls+hybrid+hybrid_ex */
self->selectedProtocol = PROTOCOL_SSL; //TODO: change
}
else
{
self->failureCode = SSL_WITH_USER_AUTH_REQUIRED_BY_SERVER;
}
break;
case (PROTOCOL_SSL | PROTOCOL_HYBRID):
/* server supports tls+hybrid */
if (self->requestedProtocol == (PROTOCOL_SSL | PROTOCOL_HYBRID))
{
/* client supports tls+hybrid */
self->selectedProtocol = PROTOCOL_SSL; //TODO: change
}
else
{
self->failureCode = HYBRID_REQUIRED_BY_SERVER;
}
break;
case PROTOCOL_SSL:
/* server supports tls */
if (self->requestedProtocol & PROTOCOL_SSL) //TODO
{
/* client supports tls */
self->selectedProtocol = PROTOCOL_SSL;
}
else
{
self->failureCode = SSL_REQUIRED_BY_SERVER;
}
break;
case PROTOCOL_RDP:
/* server supports rdp */
if (self->requestedProtocol == PROTOCOL_RDP)
{
/* client supports rdp */
self->selectedProtocol = PROTOCOL_RDP;
}
else
{
self->failureCode = SSL_NOT_ALLOWED_BY_SERVER;
}
break;
default:
/* unsupported protocol */
g_writeln("xrdp_iso_incoming: unsupported protocol %d",
self->requestedProtocol);
self->failureCode = INCONSISTENT_FLAGS; //TODO: ?
}
}
/* send connection confirm back to client */
if (xrdp_iso_send_cc(self) != 0)
{
g_writeln("xrdp_iso_incoming: xrdp_iso_send_cc returned non zero");
return 1;
}
@ -383,7 +402,7 @@ xrdp_iso_send(struct xrdp_iso *self, struct stream *s)
DEBUG((" in xrdp_iso_send"));
s_pop_layer(s, iso_hdr);
len = (int)(s->end - s->p);
len = (int) (s->end - s->p);
out_uint8(s, 3);
out_uint8(s, 0);
out_uint16_be(s, len);

8
libxrdp/xrdp_rdp.c
View File

@ -160,21 +160,21 @@ xrdp_rdp_read_config(struct xrdp_client_info *client_info)
{
if (g_strcasecmp(value, "rdp") == 0)
{
client_info->security_layer = 1;
client_info->security_layer = PROTOCOL_RDP;
}
else if (g_strcasecmp(value, "tls") == 0)
{
client_info->security_layer = 2;
client_info->security_layer = PROTOCOL_SSL;
}
else if (g_strcasecmp(value, "hybrid") == 0)
{
client_info->security_layer = 3;
client_info->security_layer = PROTOCOL_SSL | PROTOCOL_HYBRID;
}
else
{
log_message(LOG_LEVEL_ALWAYS,"Warning: Your configured security layer is"
"undefined, xrdp will negotiate client compatible");
client_info->security_layer = -1;
client_info->security_layer = PROTOCOL_SSL | PROTOCOL_HYBRID | PROTOCOL_HYBRID_EX;
}
}