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
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
|
//------------------------------------------------------------
// Copyright (c) Microsoft Corporation. All rights reserved.
//------------------------------------------------------------
namespace System.IdentityModel
{
using System.IO;
using System.Security.Cryptography;
using System.IdentityModel.Selectors;
using System.IdentityModel.Tokens;
using System.Text;
using System.Xml;
class ExclusiveCanonicalizationTransform : Transform
{
bool includeComments;
string algorithm;
string inclusiveNamespacesPrefixList;
string[] inclusivePrefixes;
string inclusiveListElementPrefix = ExclusiveC14NStrings.Prefix;
string prefix = XmlSignatureStrings.Prefix;
readonly bool isCanonicalizationMethod;
public ExclusiveCanonicalizationTransform()
: this(false)
{
}
public ExclusiveCanonicalizationTransform(bool isCanonicalizationMethod)
: this(isCanonicalizationMethod, false)
{
}
public ExclusiveCanonicalizationTransform(bool isCanonicalizationMethod, bool includeComments)
{
this.isCanonicalizationMethod = isCanonicalizationMethod;
this.includeComments = includeComments;
this.algorithm = includeComments ? XD.SecurityAlgorithmDictionary.ExclusiveC14nWithComments.Value : XD.SecurityAlgorithmDictionary.ExclusiveC14n.Value;
}
public override string Algorithm
{
get
{
return algorithm;
}
}
public bool IncludeComments
{
get
{
return this.includeComments;
}
}
public string InclusiveNamespacesPrefixList
{
get
{
return this.inclusiveNamespacesPrefixList;
}
set
{
this.inclusiveNamespacesPrefixList = value;
this.inclusivePrefixes = TokenizeInclusivePrefixList(value);
}
}
public override bool NeedsInclusiveContext
{
get { return GetInclusivePrefixes() != null; }
}
public string[] GetInclusivePrefixes()
{
return this.inclusivePrefixes;
}
CanonicalizationDriver GetConfiguredDriver(SignatureResourcePool resourcePool)
{
CanonicalizationDriver driver = resourcePool.TakeCanonicalizationDriver();
driver.IncludeComments = this.IncludeComments;
driver.SetInclusivePrefixes(this.inclusivePrefixes);
return driver;
}
// multi-transform case, inefficient path
public override object Process(object input, SignatureResourcePool resourcePool, DictionaryManager dictionaryManager)
{
if (input is XmlReader)
{
CanonicalizationDriver driver = GetConfiguredDriver(resourcePool);
driver.SetInput(input as XmlReader);
return driver.GetMemoryStream();
}
else if (input is ISecurityElement)
{
MemoryStream stream = new MemoryStream();
XmlDictionaryWriter utf8Writer = resourcePool.TakeUtf8Writer();
utf8Writer.StartCanonicalization(stream, false, null);
(input as ISecurityElement).WriteTo(utf8Writer, dictionaryManager);
utf8Writer.EndCanonicalization();
stream.Seek(0, SeekOrigin.Begin);
return stream;
}
else
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new NotSupportedException(SR.GetString(SR.UnsupportedInputTypeForTransform, input.GetType())));
}
}
// common single-transform case; fold directly into a digest
public override byte[] ProcessAndDigest(object input, SignatureResourcePool resourcePool, string digestAlgorithm, DictionaryManager dictionaryManager)
{
HashAlgorithm hash = resourcePool.TakeHashAlgorithm(digestAlgorithm);
ProcessAndDigest(input, resourcePool, hash, dictionaryManager);
return hash.Hash;
}
public void ProcessAndDigest(object input, SignatureResourcePool resourcePool, HashAlgorithm hash, DictionaryManager dictionaryManger)
{
HashStream hashStream = resourcePool.TakeHashStream(hash);
XmlReader reader = input as XmlReader;
if (reader != null)
{
ProcessReaderInput(reader, resourcePool, hashStream);
}
else if (input is ISecurityElement)
{
XmlDictionaryWriter utf8Writer = resourcePool.TakeUtf8Writer();
utf8Writer.StartCanonicalization(hashStream, this.IncludeComments, GetInclusivePrefixes());
(input as ISecurityElement).WriteTo(utf8Writer, dictionaryManger);
utf8Writer.EndCanonicalization();
}
else
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new NotSupportedException(SR.GetString(SR.UnsupportedInputTypeForTransform, input.GetType())));
}
hashStream.FlushHash();
}
void ProcessReaderInput(XmlReader reader, SignatureResourcePool resourcePool, HashStream hashStream)
{
reader.MoveToContent();
XmlDictionaryReader dictionaryReader = reader as XmlDictionaryReader;
if (dictionaryReader != null && dictionaryReader.CanCanonicalize)
{
dictionaryReader.StartCanonicalization(hashStream, this.IncludeComments, GetInclusivePrefixes());
dictionaryReader.Skip();
dictionaryReader.EndCanonicalization();
}
else
{
CanonicalizationDriver driver = GetConfiguredDriver(resourcePool);
driver.SetInput(reader);
driver.WriteTo(hashStream);
}
}
public override void ReadFrom(XmlDictionaryReader reader, DictionaryManager dictionaryManager, bool preserveComments)
{
XmlDictionaryString elementName = this.isCanonicalizationMethod ?
dictionaryManager.XmlSignatureDictionary.CanonicalizationMethod : dictionaryManager.XmlSignatureDictionary.Transform;
reader.MoveToStartElement(elementName, dictionaryManager.XmlSignatureDictionary.Namespace);
this.prefix = reader.Prefix;
bool isEmptyElement = reader.IsEmptyElement;
algorithm = reader.GetAttribute(dictionaryManager.XmlSignatureDictionary.Algorithm, null);
if (string.IsNullOrEmpty(algorithm))
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new CryptographicException(SR.GetString(SR.ID0001, dictionaryManager.XmlSignatureDictionary.Algorithm, reader.LocalName)));
}
if (algorithm == dictionaryManager.SecurityAlgorithmDictionary.ExclusiveC14nWithComments.Value)
{
// to include comments in canonicalization, two conditions need to be met
// 1. the Reference must be an xpointer.
// 2. the transform must be #withComments
includeComments = preserveComments && true;
}
else if (algorithm == dictionaryManager.SecurityAlgorithmDictionary.ExclusiveC14n.Value)
{
includeComments = false;
}
else
{
throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new CryptographicException(SR.GetString(SR.ID6005, algorithm)));
}
reader.Read();
reader.MoveToContent();
if (!isEmptyElement)
{
if (reader.IsStartElement(dictionaryManager.ExclusiveC14NDictionary.InclusiveNamespaces, dictionaryManager.ExclusiveC14NDictionary.Namespace))
{
reader.MoveToStartElement(dictionaryManager.ExclusiveC14NDictionary.InclusiveNamespaces, dictionaryManager.ExclusiveC14NDictionary.Namespace);
this.inclusiveListElementPrefix = reader.Prefix;
bool emptyElement = reader.IsEmptyElement;
// We treat PrefixList as optional Attribute.
this.InclusiveNamespacesPrefixList = reader.GetAttribute(dictionaryManager.ExclusiveC14NDictionary.PrefixList, null);
reader.Read();
if (!emptyElement)
reader.ReadEndElement();
}
reader.MoveToContent();
reader.ReadEndElement(); // Transform
}
}
public override void WriteTo(XmlDictionaryWriter writer, DictionaryManager dictionaryManager)
{
XmlDictionaryString elementName = this.isCanonicalizationMethod ?
dictionaryManager.XmlSignatureDictionary.CanonicalizationMethod : dictionaryManager.XmlSignatureDictionary.Transform;
writer.WriteStartElement(this.prefix, elementName, dictionaryManager.XmlSignatureDictionary.Namespace);
writer.WriteAttributeString(dictionaryManager.XmlSignatureDictionary.Algorithm, null, algorithm);
if (this.InclusiveNamespacesPrefixList != null)
{
writer.WriteStartElement(this.inclusiveListElementPrefix, dictionaryManager.ExclusiveC14NDictionary.InclusiveNamespaces, dictionaryManager.ExclusiveC14NDictionary.Namespace);
writer.WriteAttributeString(dictionaryManager.ExclusiveC14NDictionary.PrefixList, null, this.InclusiveNamespacesPrefixList);
writer.WriteEndElement(); // InclusiveNamespaces
}
writer.WriteEndElement(); // Transform
}
static string[] TokenizeInclusivePrefixList(string prefixList)
{
if (prefixList == null)
{
return null;
}
string[] prefixes = prefixList.Split(null);
int count = 0;
for (int i = 0; i < prefixes.Length; i++)
{
string prefix = prefixes[i];
if (prefix == "#default")
{
prefixes[count++] = string.Empty;
}
else if (prefix.Length > 0)
{
prefixes[count++] = prefix;
}
}
if (count == 0)
{
return null;
}
else if (count == prefixes.Length)
{
return prefixes;
}
else
{
string[] result = new string[count];
Array.Copy(prefixes, result, count);
return result;
}
}
}
}
|
