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
|
/*
* TLS Channels
* (C) 2011 Jack Lloyd
*
* Released under the terms of the Botan license
*/
#include <botan/tls_channel.h>
#include <botan/internal/tls_alerts.h>
#include <botan/internal/tls_state.h>
#include <botan/loadstor.h>
namespace Botan {
TLS_Channel::TLS_Channel(std::tr1::function<void (const byte[], size_t)> socket_output_fn,
std::tr1::function<void (const byte[], size_t, u16bit)> proc_fn) :
proc_fn(proc_fn),
writer(socket_output_fn),
state(0),
active(false)
{
}
TLS_Channel::~TLS_Channel()
{
close();
delete state;
state = 0;
}
size_t TLS_Channel::received_data(const byte buf[], size_t buf_size)
{
try
{
reader.add_input(buf, buf_size);
byte rec_type = CONNECTION_CLOSED;
SecureVector<byte> record;
while(!reader.currently_empty())
{
const size_t bytes_needed = reader.get_record(rec_type, record);
if(bytes_needed > 0)
return bytes_needed;
if(rec_type == APPLICATION_DATA)
{
if(active)
{
/*
* OpenSSL among others sends empty records in versions
* before TLS v1.1 in order to randomize the IV of the
* following record. Avoid spurious callbacks.
*/
if(record.size() > 0)
proc_fn(&record[0], record.size(), NULL_ALERT);
}
else
{
throw Unexpected_Message("Application data before handshake done");
}
}
else if(rec_type == HANDSHAKE || rec_type == CHANGE_CIPHER_SPEC)
{
read_handshake(rec_type, record);
}
else if(rec_type == ALERT)
{
Alert alert_msg(record);
proc_fn(0, 0, alert_msg.type());
if(alert_msg.is_fatal() || alert_msg.type() == CLOSE_NOTIFY)
{
if(alert_msg.type() == CLOSE_NOTIFY)
alert(FATAL, CLOSE_NOTIFY);
else
alert(FATAL, NULL_ALERT);
}
}
else
throw Unexpected_Message("Unknown message type received");
}
return 0; // on a record boundary
}
catch(TLS_Exception& e)
{
alert(FATAL, e.type());
throw;
}
catch(Decoding_Error& e)
{
alert(FATAL, DECODE_ERROR);
throw;
}
catch(std::exception& e)
{
alert(FATAL, INTERNAL_ERROR);
throw;
}
}
/*
* Split up and process handshake messages
*/
void TLS_Channel::read_handshake(byte rec_type,
const MemoryRegion<byte>& rec_buf)
{
if(rec_type == HANDSHAKE)
state->queue.write(&rec_buf[0], rec_buf.size());
while(true)
{
Handshake_Type type = HANDSHAKE_NONE;
SecureVector<byte> contents;
if(rec_type == HANDSHAKE)
{
if(state->queue.size() >= 4)
{
byte head[4] = { 0 };
state->queue.peek(head, 4);
const size_t length = make_u32bit(0, head[1], head[2], head[3]);
if(state->queue.size() >= length + 4)
{
type = static_cast<Handshake_Type>(head[0]);
contents.resize(length);
state->queue.read(head, 4);
state->queue.read(&contents[0], contents.size());
}
}
}
else if(rec_type == CHANGE_CIPHER_SPEC)
{
if(state->queue.size() == 0 && rec_buf.size() == 1 && rec_buf[0] == 1)
type = HANDSHAKE_CCS;
else
throw Decoding_Error("Malformed ChangeCipherSpec message");
}
else
throw Decoding_Error("Unknown message type in handshake processing");
if(type == HANDSHAKE_NONE)
break;
process_handshake_msg(type, contents);
if(type == HANDSHAKE_CCS || !state)
break;
}
}
void TLS_Channel::queue_for_sending(const byte buf[], size_t buf_size)
{
if(active)
{
while(!pre_handshake_write_queue.end_of_data())
{
SecureVector<byte> q_buf(1024);
const size_t got = pre_handshake_write_queue.read(&q_buf[0], q_buf.size());
writer.send(APPLICATION_DATA, &q_buf[0], got);
}
writer.send(APPLICATION_DATA, buf, buf_size);
}
else
pre_handshake_write_queue.write(buf, buf_size);
}
void TLS_Channel::alert(Alert_Level alert_level, Alert_Type alert_code)
{
if(alert_code != NULL_ALERT)
{
try
{
writer.alert(alert_level, alert_code);
}
catch(...) { /* swallow it */ }
}
if(active && alert_level == FATAL)
{
reader.reset();
writer.reset();
delete state;
state = 0;
active = false;
}
}
}
|
