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
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
|
using System;
using System.IO;
using Org.BouncyCastle.Utilities;
using Org.BouncyCastle.Utilities.IO;
namespace Org.BouncyCastle.Bcpg
{
/// <remarks>Reader for PGP objects.</remarks>
public class BcpgInputStream
: BaseInputStream
{
private Stream m_in;
private bool next = false;
private int nextB;
internal static BcpgInputStream Wrap(
Stream inStr)
{
if (inStr is BcpgInputStream)
{
return (BcpgInputStream) inStr;
}
return new BcpgInputStream(inStr);
}
private BcpgInputStream(
Stream inputStream)
{
this.m_in = inputStream;
}
public override int ReadByte()
{
if (next)
{
next = false;
return nextB;
}
return m_in.ReadByte();
}
public override int Read(byte[] buffer, int offset, int count)
{
if (!next)
return m_in.Read(buffer, offset, count);
Streams.ValidateBufferArguments(buffer, offset, count);
if (nextB < 0)
return 0;
buffer[offset] = (byte)nextB;
next = false;
return 1;
}
public byte[] ReadAll()
{
return Streams.ReadAll(this);
}
public void ReadFully(byte[] buffer, int offset, int count)
{
if (Streams.ReadFully(this, buffer, offset, count) < count)
throw new EndOfStreamException();
}
public void ReadFully(byte[] buffer)
{
ReadFully(buffer, 0, buffer.Length);
}
#if NETCOREAPP2_1_OR_GREATER || NETSTANDARD2_1_OR_GREATER
public void ReadFully(Span<byte> buffer)
{
if (Streams.ReadFully(this, buffer) < buffer.Length)
throw new EndOfStreamException();
}
#endif
/// <summary>Returns the next packet tag in the stream.</summary>
public PacketTag NextPacketTag()
{
if (!next)
{
try
{
nextB = m_in.ReadByte();
}
catch (EndOfStreamException)
{
nextB = -1;
}
next = true;
}
if (nextB < 0)
return (PacketTag)nextB;
int maskB = nextB & 0x3f;
if ((nextB & 0x40) == 0) // old
{
maskB >>= 2;
}
return (PacketTag)maskB;
}
public Packet ReadPacket()
{
int hdr = this.ReadByte();
if (hdr < 0)
{
return null;
}
if ((hdr & 0x80) == 0)
{
throw new IOException("invalid header encountered");
}
bool newPacket = (hdr & 0x40) != 0;
PacketTag tag = 0;
int bodyLen = 0;
bool partial = false;
if (newPacket)
{
tag = (PacketTag)(hdr & 0x3f);
int l = this.ReadByte();
if (l < 192)
{
bodyLen = l;
}
else if (l <= 223)
{
int b = m_in.ReadByte();
bodyLen = ((l - 192) << 8) + (b) + 192;
}
else if (l == 255)
{
bodyLen = (m_in.ReadByte() << 24) | (m_in.ReadByte() << 16)
| (m_in.ReadByte() << 8) | m_in.ReadByte();
}
else
{
partial = true;
bodyLen = 1 << (l & 0x1f);
}
}
else
{
int lengthType = hdr & 0x3;
tag = (PacketTag)((hdr & 0x3f) >> 2);
switch (lengthType)
{
case 0:
bodyLen = this.ReadByte();
break;
case 1:
bodyLen = (this.ReadByte() << 8) | this.ReadByte();
break;
case 2:
bodyLen = (this.ReadByte() << 24) | (this.ReadByte() << 16)
| (this.ReadByte() << 8) | this.ReadByte();
break;
case 3:
partial = true;
break;
default:
throw new IOException("unknown length type encountered");
}
}
BcpgInputStream objStream;
if (bodyLen == 0 && partial)
{
objStream = this;
}
else
{
PartialInputStream pis = new PartialInputStream(this, partial, bodyLen);
Stream buf = new BufferedStream(pis);
objStream = new BcpgInputStream(buf);
}
switch (tag)
{
case PacketTag.Reserved:
return new InputStreamPacket(objStream);
case PacketTag.PublicKeyEncryptedSession:
return new PublicKeyEncSessionPacket(objStream);
case PacketTag.Signature:
return new SignaturePacket(objStream);
case PacketTag.SymmetricKeyEncryptedSessionKey:
return new SymmetricKeyEncSessionPacket(objStream);
case PacketTag.OnePassSignature:
return new OnePassSignaturePacket(objStream);
case PacketTag.SecretKey:
return new SecretKeyPacket(objStream);
case PacketTag.PublicKey:
return new PublicKeyPacket(objStream);
case PacketTag.SecretSubkey:
return new SecretSubkeyPacket(objStream);
case PacketTag.CompressedData:
return new CompressedDataPacket(objStream);
case PacketTag.SymmetricKeyEncrypted:
return new SymmetricEncDataPacket(objStream);
case PacketTag.Marker:
return new MarkerPacket(objStream);
case PacketTag.LiteralData:
return new LiteralDataPacket(objStream);
case PacketTag.Trust:
return new TrustPacket(objStream);
case PacketTag.UserId:
return new UserIdPacket(objStream);
case PacketTag.UserAttribute:
return new UserAttributePacket(objStream);
case PacketTag.PublicSubkey:
return new PublicSubkeyPacket(objStream);
case PacketTag.SymmetricEncryptedIntegrityProtected:
return new SymmetricEncIntegrityPacket(objStream);
case PacketTag.ModificationDetectionCode:
return new ModDetectionCodePacket(objStream);
case PacketTag.Experimental1:
case PacketTag.Experimental2:
case PacketTag.Experimental3:
case PacketTag.Experimental4:
return new ExperimentalPacket(tag, objStream);
default:
throw new IOException("unknown packet type encountered: " + tag);
}
}
public PacketTag SkipMarkerPackets()
{
PacketTag tag;
while ((tag = NextPacketTag()) == PacketTag.Marker)
{
ReadPacket();
}
return tag;
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
Platform.Dispose(m_in);
}
base.Dispose(disposing);
}
/// <summary>
/// A stream that overlays our input stream, allowing the user to only read a segment of it.
/// NB: dataLength will be negative if the segment length is in the upper range above 2**31.
/// </summary>
private class PartialInputStream
: BaseInputStream
{
private BcpgInputStream m_in;
private bool partial;
private int dataLength;
internal PartialInputStream(
BcpgInputStream bcpgIn,
bool partial,
int dataLength)
{
this.m_in = bcpgIn;
this.partial = partial;
this.dataLength = dataLength;
}
public override int ReadByte()
{
do
{
if (dataLength != 0)
{
int ch = m_in.ReadByte();
if (ch < 0)
{
throw new EndOfStreamException("Premature end of stream in PartialInputStream");
}
dataLength--;
return ch;
}
}
while (partial && ReadPartialDataLength() >= 0);
return -1;
}
public override int Read(byte[] buffer, int offset, int count)
{
Streams.ValidateBufferArguments(buffer, offset, count);
do
{
if (dataLength != 0)
{
int readLen = (dataLength > count || dataLength < 0) ? count : dataLength;
int len = m_in.Read(buffer, offset, readLen);
if (len < 1)
{
throw new EndOfStreamException("Premature end of stream in PartialInputStream");
}
dataLength -= len;
return len;
}
}
while (partial && ReadPartialDataLength() >= 0);
return 0;
}
private int ReadPartialDataLength()
{
int l = m_in.ReadByte();
if (l < 0)
{
return -1;
}
partial = false;
if (l < 192)
{
dataLength = l;
}
else if (l <= 223)
{
dataLength = ((l - 192) << 8) + (m_in.ReadByte()) + 192;
}
else if (l == 255)
{
dataLength = (m_in.ReadByte() << 24) | (m_in.ReadByte() << 16)
| (m_in.ReadByte() << 8) | m_in.ReadByte();
}
else
{
partial = true;
dataLength = 1 << (l & 0x1f);
}
return 0;
}
}
}
}
|
