1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
/*
* ModSecurity for Apache 2.x, http://www.modsecurity.org/
* Copyright (c) 2004-2022 Trustwave Holdings, Inc. (http://www.trustwave.com/)
*
* You may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* If any of the files related to licensing are missing or if you have any
* other questions related to licensing please contact Trustwave Holdings, Inc.
* directly using the email address security@modsecurity.org.
*/
#include "msc_xml.h"
static xmlParserInputBufferPtr
xml_unload_external_entity(const char *URI, xmlCharEncoding enc) {
return NULL;
}
/**
* Initialise XML parser.
*/
int xml_init(modsec_rec *msr, char **error_msg) {
xmlParserInputBufferCreateFilenameFunc entity;
if (error_msg == NULL) return -1;
*error_msg = NULL;
msr->xml = apr_pcalloc(msr->mp, sizeof(xml_data));
if (msr->xml == NULL) return -1;
if(msr->txcfg->xml_external_entity == 0) {
entity = xmlParserInputBufferCreateFilenameDefault(xml_unload_external_entity);
}
return 1;
}
#if 0
static void xml_receive_sax_error(void *data, const char *msg, ...) {
modsec_rec *msr = (modsec_rec *)data;
char message[256];
if (msr == NULL) return;
apr_snprintf(message, sizeof(message), "%s (line %d offset %d)",
log_escape_nq(msr->mp, msr->xml->parsing_ctx->lastError.message),
msr->xml->parsing_ctx->lastError.line,
msr->xml->parsing_ctx->lastError.int2);
msr_log(msr, 5, "XML: Parsing error: %s", message);
}
#endif
/**
* Feed one chunk of data to the XML parser.
*/
int xml_process_chunk(modsec_rec *msr, const char *buf, unsigned int size, char **error_msg) {
if (error_msg == NULL) return -1;
*error_msg = NULL;
/* We want to initialise our parsing context here, to
* enable us to pass it the first chunk of data so that
* it can attempt to auto-detect the encoding.
*/
if (msr->xml->parsing_ctx == NULL) {
/* First invocation. */
msr_log(msr, 4, "XML: Initialising parser.");
/* NOTE When Sax interface is used libxml will not
* create the document object, but we need it.
msr->xml->sax_handler = (xmlSAXHandler *)apr_pcalloc(msr->mp, sizeof(xmlSAXHandler));
if (msr->xml->sax_handler == NULL) return -1;
msr->xml->sax_handler->error = xml_receive_sax_error;
msr->xml->sax_handler->warning = xml_receive_sax_error;
msr->xml->parsing_ctx = xmlCreatePushParserCtxt(msr->xml->sax_handler, msr,
buf, size, "body.xml");
*/
msr->xml->parsing_ctx = xmlCreatePushParserCtxt(NULL, NULL, buf, size, "body.xml");
if (msr->xml->parsing_ctx == NULL) {
*error_msg = apr_psprintf(msr->mp, "XML: Failed to create parsing context.");
return -1;
}
} else {
/* Not a first invocation. */
xmlParseChunk(msr->xml->parsing_ctx, buf, size, 0);
if (msr->xml->parsing_ctx->wellFormed != 1) {
*error_msg = apr_psprintf(msr->mp, "XML: Failed parsing document.");
return -1;
}
}
return 1;
}
/**
* Finalise XML parsing.
*/
int xml_complete(modsec_rec *msr, char **error_msg) {
if (error_msg == NULL) return -1;
*error_msg = NULL;
/* Only if we have a context, meaning we've done some work. */
if (msr->xml->parsing_ctx != NULL) {
/* This is how we signalise the end of parsing to libxml. */
xmlParseChunk(msr->xml->parsing_ctx, NULL, 0, 1);
/* Preserve the results for our reference. */
msr->xml->well_formed = msr->xml->parsing_ctx->wellFormed;
msr->xml->doc = msr->xml->parsing_ctx->myDoc;
/* Clean up everything else. */
xmlFreeParserCtxt(msr->xml->parsing_ctx);
msr->xml->parsing_ctx = NULL;
msr_log(msr, 4, "XML: Parsing complete (well_formed %u).", msr->xml->well_formed);
if (msr->xml->well_formed != 1) {
*error_msg = apr_psprintf(msr->mp, "XML: Failed parsing document.");
return -1;
}
}
return 1;
}
/**
* Frees the resources used for XML parsing.
*/
apr_status_t xml_cleanup(modsec_rec *msr) {
if (msr->xml->parsing_ctx != NULL) {
if (msr->xml->parsing_ctx->myDoc) {
xmlFreeDoc(msr->xml->parsing_ctx->myDoc);
if (msr->xml->parsing_ctx->myDoc == msr->xml->doc) {
msr->xml->doc = NULL;
}
}
xmlFreeParserCtxt(msr->xml->parsing_ctx);
msr->xml->parsing_ctx = NULL;
}
if (msr->xml->doc != NULL) {
xmlFreeDoc(msr->xml->doc);
msr->xml->doc = NULL;
}
return 1;
}
|
