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
|
package org.bouncycastle.mail.smime;
import java.io.IOException;
import java.security.NoSuchAlgorithmException;
import java.security.Provider;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import javax.crypto.KeyGenerator;
import javax.mail.Header;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.Session;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import org.bouncycastle.cms.CMSEnvelopedGenerator;
import org.bouncycastle.util.Strings;
/**
* super class of the various generators.
*/
public class SMIMEGenerator
{
private static Map BASE_CIPHER_NAMES = new HashMap();
static
{
BASE_CIPHER_NAMES.put(CMSEnvelopedGenerator.DES_EDE3_CBC, "DESEDE");
BASE_CIPHER_NAMES.put(CMSEnvelopedGenerator.AES128_CBC, "AES");
BASE_CIPHER_NAMES.put(CMSEnvelopedGenerator.AES192_CBC, "AES");
BASE_CIPHER_NAMES.put(CMSEnvelopedGenerator.AES256_CBC, "AES");
}
protected boolean useBase64 = true;
protected String encoding = "base64"; // default sets base64
/**
* base constructor
*/
protected SMIMEGenerator()
{
}
/**
* set the content-transfer-encoding for the CMS block (enveloped data, signature, etc...) in the message.
*
* @param encoding the encoding to use, default "base64", use "binary" for a binary encoding.
*/
public void setContentTransferEncoding(
String encoding)
{
this.encoding = encoding;
this.useBase64 = Strings.toLowerCase(encoding).equals("base64");
}
/**
* Make sure we have a valid content body part - setting the headers
* with defaults if neccessary.
*/
protected MimeBodyPart makeContentBodyPart(
MimeBodyPart content)
throws SMIMEException
{
//
// add the headers to the body part - if they are missing, in
// the event they have already been set the content settings override
// any defaults that might be set.
//
try
{
MimeMessage msg = new MimeMessage((Session)null);
Enumeration e = content.getAllHeaders();
msg.setDataHandler(content.getDataHandler());
while (e.hasMoreElements())
{
Header hdr =(Header)e.nextElement();
msg.setHeader(hdr.getName(), hdr.getValue());
}
msg.saveChanges();
//
// we do this to make sure at least the default headers are
// set in the body part.
//
e = msg.getAllHeaders();
while (e.hasMoreElements())
{
Header hdr =(Header)e.nextElement();
if (Strings.toLowerCase(hdr.getName()).startsWith("content-"))
{
content.setHeader(hdr.getName(), hdr.getValue());
}
}
}
catch (MessagingException e)
{
throw new SMIMEException("exception saving message state.", e);
}
return content;
}
/**
* extract an appropriate body part from the passed in MimeMessage
*/
protected MimeBodyPart makeContentBodyPart(
MimeMessage message)
throws SMIMEException
{
MimeBodyPart content = new MimeBodyPart();
//
// add the headers to the body part.
//
try
{
message.removeHeader("Message-Id");
message.removeHeader("Mime-Version");
// JavaMail has a habit of reparsing some content types, if the bodypart is
// a multipart it might be signed, we rebuild the body part using the raw input stream for the message.
try
{
if (message.getContent() instanceof Multipart)
{
content.setContent(message.getRawInputStream(), message.getContentType());
extractHeaders(content, message);
return content;
}
}
catch (MessagingException e)
{
// fall back to usual method below
}
content.setContent(message.getContent(), message.getContentType());
content.setDataHandler(message.getDataHandler());
extractHeaders(content, message);
}
catch (MessagingException e)
{
throw new SMIMEException("exception saving message state.", e);
}
catch (IOException e)
{
throw new SMIMEException("exception getting message content.", e);
}
return content;
}
private void extractHeaders(MimeBodyPart content, MimeMessage message)
throws MessagingException
{
Enumeration e = message.getAllHeaders();
while (e.hasMoreElements())
{
Header hdr =(Header)e.nextElement();
content.addHeader(hdr.getName(), hdr.getValue());
}
}
protected KeyGenerator createSymmetricKeyGenerator(
String encryptionOID,
Provider provider)
throws NoSuchAlgorithmException
{
try
{
return createKeyGenerator(encryptionOID, provider);
}
catch (NoSuchAlgorithmException e)
{
try
{
String algName = (String)BASE_CIPHER_NAMES.get(encryptionOID);
if (algName != null)
{
return createKeyGenerator(algName, provider);
}
}
catch (NoSuchAlgorithmException ex)
{
// ignore
}
if (provider != null)
{
return createSymmetricKeyGenerator(encryptionOID, null);
}
throw e;
}
}
private KeyGenerator createKeyGenerator(
String algName,
Provider provider)
throws NoSuchAlgorithmException
{
if (provider != null)
{
return KeyGenerator.getInstance(algName, provider);
}
else
{
return KeyGenerator.getInstance(algName);
}
}
}
|
