wireshark/plugins/epan/opcua/opcua_transport_layer.c

300 lines
14 KiB
C

/******************************************************************************
** Copyright (C) 2006-2009 ascolab GmbH. All Rights Reserved.
** Web: http://www.ascolab.com
**
** SPDX-License-Identifier: GPL-2.0-or-later
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
** Project: OpcUa Wireshark Plugin
**
** Description: OpcUa Transport Layer Decoder.
**
** Author: Gerhard Gappmeier <gerhard.gappmeier@ascolab.com>
******************************************************************************/
#include "config.h"
#include <epan/packet.h>
#include <epan/conversation.h>
#include "epan/column-utils.h"
#include "opcua_security_layer.h"
#include "opcua_application_layer.h"
#include "opcua_simpletypes.h"
#include "opcua_transport_layer.h"
#include "opcua_servicetable.h"
static int hf_opcua_transport_type;
static int hf_opcua_transport_chunk;
static int hf_opcua_transport_size;
static int hf_opcua_transport_ver;
static int hf_opcua_transport_scid;
static int hf_opcua_transport_rbs;
static int hf_opcua_transport_sbs;
static int hf_opcua_transport_mms;
static int hf_opcua_transport_mcc;
static int hf_opcua_transport_endpoint;
static int hf_opcua_transport_suri;
static int hf_opcua_transport_error;
static int hf_opcua_transport_reason;
static int hf_opcua_transport_spu;
static int hf_opcua_transport_scert;
static int hf_opcua_transport_rcthumb;
static int hf_opcua_transport_seq;
static int hf_opcua_transport_rqid;
/** subtree types */
extern gint ett_opcua_nodeid;
extern gint ett_opcua_extensionobject;
extern gint proto_opcua;
/** Defined security policy URL from Part 7 OPC UA Specification. */
#define UA_SECURITY_POLICY_NONE_STRING "http://opcfoundation.org/UA/SecurityPolicy#None"
/** Defined security policy URL from Part 7 OPC UA Specification. */
#define UA_SECURITY_POLICY_BASIC128RSA15_STRING "http://opcfoundation.org/UA/SecurityPolicy#Basic128Rsa15"
/** Defined security policy URL from Part 7 OPC UA Specification. */
#define UA_SECURITY_POLICY_BASIC256_STRING "http://opcfoundation.org/UA/SecurityPolicy#Basic256"
/** Defined security policy URL from Part 7 OPC UA Specification. */
#define UA_SECURITY_POLICY_BASIC256SHA256_STRING "http://opcfoundation.org/UA/SecurityPolicy#Basic256Sha256"
/** Defined security policy URL from Part 7 OPC UA Specification. */
#define UA_SECURITY_POLICY_AES128_SHA256_RSAOAEP_STRING "http://opcfoundation.org/UA/SecurityPolicy#Aes128_Sha256_RsaOaep"
/** Defined security policy URL from Part 7 OPC UA Specification. */
#define UA_SECURITY_POLICY_AES256_SHA256_RSAPSS_STRING "http://opcfoundation.org/UA/SecurityPolicy#Aes256_Sha256_RsaPss"
/** Register transport layer types. */
void registerTransportLayerTypes(int proto)
{
static hf_register_info hf[] =
{
/* id full name abbreviation type display strings bitmask blurb HFILL */
{&hf_opcua_transport_type, {"Message Type", "opcua.transport.type", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_chunk, {"Chunk Type", "opcua.transport.chunk", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_size, {"Message Size", "opcua.transport.size", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_ver, {"Version", "opcua.transport.ver", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_scid, {"SecureChannelId", "opcua.transport.scid", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_rbs, {"ReceiveBufferSize", "opcua.transport.rbs", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_sbs, {"SendBufferSize", "opcua.transport.sbs", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_mms, {"MaxMessageSize", "opcua.transport.mms", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_mcc, {"MaxChunkCount", "opcua.transport.mcc", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_endpoint, {"EndpointUrl", "opcua.transport.endpoint", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_suri, {"ServerUri", "opcua.transport.suri", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_error, {"Error", "opcua.transport.error", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_reason, {"Reason", "opcua.transport.reason", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_spu, {"SecurityPolicyUri", "opcua.security.spu", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_scert, {"SenderCertificate", "opcua.security.scert", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_rcthumb, {"ReceiverCertificateThumbprint", "opcua.security.rcthumb", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_seq, {"SequenceNumber", "opcua.security.seq", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL}},
{&hf_opcua_transport_rqid, {"RequestId", "opcua.security.rqid", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL}},
};
proto_register_field_array(proto, hf, array_length(hf));
}
void parseMessageHeader(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, gint *pOffset, struct ua_metadata *data _U_)
{
proto_tree_add_item(tree, hf_opcua_transport_type, tvb, *pOffset, 3, ENC_ASCII|ENC_NA); *pOffset+=3;
proto_tree_add_item(tree, hf_opcua_transport_chunk, tvb, *pOffset, 1, ENC_ASCII|ENC_NA); *pOffset+=1;
proto_tree_add_item(tree, hf_opcua_transport_size, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
}
/* Transport Layer: message parsers */
int parseHello(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, gint *pOffset, struct ua_metadata *data _U_)
{
parseMessageHeader(tree, tvb, pinfo, pOffset, data);
proto_tree_add_item(tree, hf_opcua_transport_ver, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
proto_tree_add_item(tree, hf_opcua_transport_rbs, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
proto_tree_add_item(tree, hf_opcua_transport_sbs, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
proto_tree_add_item(tree, hf_opcua_transport_mms, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
proto_tree_add_item(tree, hf_opcua_transport_mcc, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
parseString(tree, tvb, pinfo, pOffset, hf_opcua_transport_endpoint);
return -1;
}
int parseAcknowledge(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, gint *pOffset, struct ua_metadata *data _U_)
{
parseMessageHeader(tree, tvb, pinfo, pOffset, data);
proto_tree_add_item(tree, hf_opcua_transport_ver, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
proto_tree_add_item(tree, hf_opcua_transport_rbs, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
proto_tree_add_item(tree, hf_opcua_transport_sbs, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
proto_tree_add_item(tree, hf_opcua_transport_mms, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
proto_tree_add_item(tree, hf_opcua_transport_mcc, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
return -1;
}
int parseError(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, gint *pOffset, struct ua_metadata *data _U_)
{
parseMessageHeader(tree, tvb, pinfo, pOffset, data);
parseStatusCode(tree, tvb, pinfo, pOffset, hf_opcua_transport_error);
parseString(tree, tvb, pinfo, pOffset, hf_opcua_transport_reason);
return -1;
}
int parseReverseHello(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, gint *pOffset, struct ua_metadata *data _U_)
{
parseMessageHeader(tree, tvb, pinfo, pOffset, data);
parseString(tree, tvb, pinfo, pOffset, hf_opcua_transport_suri);
parseString(tree, tvb, pinfo, pOffset, hf_opcua_transport_endpoint);
return -1;
}
int parseMessage(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, gint *pOffset, struct ua_metadata *data _U_)
{
parseMessageHeader(tree, tvb, pinfo, pOffset, data);
proto_tree_add_item(tree, hf_opcua_transport_scid, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
return -1;
}
int parseAbort(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo _U_, gint *pOffset, struct ua_metadata *data _U_)
{
parseMessageHeader(tree, tvb, pinfo, pOffset, data);
parseStatusCode(tree, tvb, pinfo, pOffset, hf_opcua_transport_error);
parseString(tree, tvb, pinfo, pOffset, hf_opcua_transport_reason);
return -1;
}
int parseService(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, gint *pOffset, struct ua_metadata *data _U_)
{
proto_item *ti;
proto_item *ti_inner;
proto_tree *encobj_tree;
proto_tree *nodeid_tree;
int ServiceId = 0;
/* add encodeable object subtree */
encobj_tree = proto_tree_add_subtree(tree, tvb, *pOffset, -1, ett_opcua_extensionobject, &ti, "Message: Encodeable Object");
/* add nodeid subtree */
nodeid_tree = proto_tree_add_subtree(encobj_tree, tvb, *pOffset, -1, ett_opcua_nodeid, &ti_inner, "TypeId: ExpandedNodeId");
ServiceId = parseServiceNodeId(nodeid_tree, tvb, pOffset);
proto_item_set_end(ti_inner, tvb, *pOffset);
if (ServiceId >= 0) {
dispatchService(encobj_tree, tvb, pinfo, pOffset, ServiceId);
}
proto_item_set_end(ti, tvb, *pOffset);
return ServiceId;
}
/**
* Stores the messages mode and signature length for this TCP connection.
* We need to know this mode in the following message to decide if decryption is required or not.
*/
void store_encryption_info(packet_info *pinfo, enum ua_message_mode mode, uint8_t sig_len)
{
conversation_t *conv = find_conversation_pinfo(pinfo, 0);
if (conv) {
uintptr_t data = (uintptr_t)mode;
data |= ((uintptr_t)sig_len << 8);
conversation_add_proto_data(conv, proto_opcua, (gpointer)data);
}
}
/** Returns the message mode and signature length for current TCP connection. */
void get_encryption_info(packet_info *pinfo, enum ua_message_mode *mode, uint8_t *sig_len)
{
conversation_t *conv = find_conversation_pinfo(pinfo, 0);
if (conv) {
uintptr_t data = (uintptr_t)conversation_get_proto_data(conv, proto_opcua);
if (data == 0) {
*mode = g_opcua_default_sig_len ? UA_MessageMode_MaybeEncrypted : UA_MessageMode_None;
*sig_len = g_opcua_default_sig_len;
} else {
*mode = (enum ua_message_mode)(data & 0xff);
*sig_len = (uintptr_t)(data >> 8);
}
}
}
/**
* Compares an unterminated string of a string constant.
*
* @param text Unterminated string to compare.
* @param text_len String data.
* @param ref_text Zero terminated string constant to compare with.
*
* @return 0 if equal, -1 if not.
*/
static int opcua_string_compare(const char *text, gint text_len, const char *ref_text)
{
gint len = (gint)strlen(ref_text);
if (text_len == len && memcmp(text, ref_text, len) == 0) return 0;
return -1;
}
int parseOpenSecureChannel(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, gint *pOffset, struct ua_metadata *data)
{
const guint8 *sec_policy = NULL;
gint sec_policy_len = 0;
int ServiceId = -1;
bool encrypted = false;
// Message Header
proto_tree_add_item(tree, hf_opcua_transport_type, tvb, *pOffset, 3, ENC_ASCII|ENC_NA); *pOffset+=3;
proto_tree_add_item(tree, hf_opcua_transport_chunk, tvb, *pOffset, 1, ENC_ASCII|ENC_NA); *pOffset+=1;
proto_tree_add_item(tree, hf_opcua_transport_size, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
proto_tree_add_item(tree, hf_opcua_transport_scid, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
// Asym Security Header
parseString_ret_string_and_length(tree, tvb, pinfo, pOffset, hf_opcua_transport_spu, &sec_policy, &sec_policy_len);
parseCertificate(tree, tvb, pinfo, pOffset, hf_opcua_transport_scert);
parseByteString(tree, tvb, pinfo, pOffset, hf_opcua_transport_rcthumb);
if (opcua_string_compare(sec_policy, sec_policy_len, UA_SECURITY_POLICY_NONE_STRING ) == 0) {
store_encryption_info(pinfo, UA_MessageMode_None, 0);
} else {
guint8 sig_len = 0;
// OPN is always encrypted for Policies != None, for both message modes Sign and SignAndEncrypted
encrypted = true;
// determine signature length based on security policy
if (opcua_string_compare(sec_policy, sec_policy_len, UA_SECURITY_POLICY_BASIC128RSA15_STRING ) == 0) {
sig_len = 20;
} else if (opcua_string_compare(sec_policy, sec_policy_len, UA_SECURITY_POLICY_BASIC256_STRING ) == 0) {
sig_len = 20;
} else if (opcua_string_compare(sec_policy, sec_policy_len, UA_SECURITY_POLICY_BASIC256SHA256_STRING ) == 0) {
sig_len = 32;
} else if (opcua_string_compare(sec_policy, sec_policy_len, UA_SECURITY_POLICY_AES128_SHA256_RSAOAEP_STRING ) == 0) {
sig_len = 32;
} else if (opcua_string_compare(sec_policy, sec_policy_len, UA_SECURITY_POLICY_AES256_SHA256_RSAPSS_STRING ) == 0) {
sig_len = 32;
}
// We don't know the messagemode without decrypting the OPN, so we assume it is SignAndEncrypt,
// we will try to decode the next service (CreateSession) and if it succeeds we change the mode to Sign
// or SignAndEncrypt accordingly
store_encryption_info(pinfo, UA_MessageMode_MaybeEncrypted, sig_len);
}
data->encrypted = encrypted;
if (!encrypted) {
parseSequenceHeader(tree, tvb, pOffset, data);
ServiceId = parseService(tree, tvb, pinfo,pOffset, data);
}
return ServiceId;
}
int parseCloseSecureChannel(proto_tree *tree, tvbuff_t *tvb, packet_info *pinfo, gint *pOffset, struct ua_metadata *data _U_)
{
parseMessageHeader(tree, tvb, pinfo, pOffset, data);
proto_tree_add_item(tree, hf_opcua_transport_scid, tvb, *pOffset, 4, ENC_LITTLE_ENDIAN); *pOffset+=4;
return -1;
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/