forked from nodejs/node
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathnode_crypto_clienthello.cc
More file actions
227 lines (187 loc) · 5.47 KB
/
node_crypto_clienthello.cc
File metadata and controls
227 lines (187 loc) · 5.47 KB
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
#include "node_crypto_clienthello.h"
#include "node_crypto_clienthello-inl.h"
#include "node_buffer.h" // Buffer
namespace node {
void ClientHelloParser::Parse(const uint8_t* data, size_t avail) {
switch (state_) {
case kWaiting:
if (!ParseRecordHeader(data, avail))
break;
// Fall through
case kTLSHeader:
ParseHeader(data, avail);
break;
case kPaused:
// Just nop
case kEnded:
// Already ended, just ignore it
break;
default:
break;
}
}
bool ClientHelloParser::ParseRecordHeader(const uint8_t* data, size_t avail) {
// >= 5 bytes for header parsing
if (avail < 5)
return false;
if (data[0] == kChangeCipherSpec ||
data[0] == kAlert ||
data[0] == kHandshake ||
data[0] == kApplicationData) {
frame_len_ = (data[3] << 8) + data[4];
state_ = kTLSHeader;
body_offset_ = 5;
} else {
End();
return false;
}
// Sanity check (too big frame, or too small)
// Let OpenSSL handle it
if (frame_len_ >= kMaxTLSFrameLen) {
End();
return false;
}
return true;
}
void ClientHelloParser::ParseHeader(const uint8_t* data, size_t avail) {
ClientHello hello;
// >= 5 + frame size bytes for frame parsing
if (body_offset_ + frame_len_ > avail)
return;
// Check hello protocol version. Protocol tuples that we know about:
//
// (3,1) TLS v1.0
// (3,2) TLS v1.1
// (3,3) TLS v1.2
//
if (data[body_offset_ + 4] != 0x03 ||
data[body_offset_ + 5] < 0x01 ||
data[body_offset_ + 5] > 0x03) {
goto fail;
}
if (data[body_offset_] == kClientHello) {
if (state_ == kTLSHeader) {
if (!ParseTLSClientHello(data, avail))
goto fail;
} else {
// We couldn't get here, but whatever
goto fail;
}
// Check if we overflowed (do not reply with any private data)
if (session_id_ == nullptr ||
session_size_ > 32 ||
session_id_ + session_size_ > data + avail) {
goto fail;
}
}
state_ = kPaused;
hello.session_id_ = session_id_;
hello.session_size_ = session_size_;
hello.has_ticket_ = tls_ticket_ != nullptr && tls_ticket_size_ != 0;
hello.ocsp_request_ = ocsp_request_;
hello.servername_ = servername_;
hello.servername_size_ = static_cast<uint8_t>(servername_size_);
onhello_cb_(cb_arg_, hello);
return;
fail:
return End();
}
void ClientHelloParser::ParseExtension(const uint16_t type,
const uint8_t* data,
size_t len) {
// NOTE: In case of anything we're just returning back, ignoring the problem.
// That's because we're heavily relying on OpenSSL to solve any problem with
// incoming data.
switch (type) {
case kServerName:
{
if (len < 2)
return;
uint32_t server_names_len = (data[0] << 8) + data[1];
if (server_names_len + 2 > len)
return;
for (size_t offset = 2; offset < 2 + server_names_len; ) {
if (offset + 3 > len)
return;
uint8_t name_type = data[offset];
if (name_type != kServernameHostname)
return;
uint16_t name_len = (data[offset + 1] << 8) + data[offset + 2];
offset += 3;
if (offset + name_len > len)
return;
servername_ = data + offset;
servername_size_ = name_len;
offset += name_len;
}
}
break;
case kStatusRequest:
// We are ignoring any data, just indicating the presence of extension
if (len < kMinStatusRequestSize)
return;
// Unknown type, ignore it
if (data[0] != kStatusRequestOCSP)
break;
// Ignore extensions, they won't work with caching on backend anyway
ocsp_request_ = 1;
break;
case kTLSSessionTicket:
tls_ticket_size_ = len;
tls_ticket_ = data + len;
break;
default:
// Ignore
break;
}
}
bool ClientHelloParser::ParseTLSClientHello(const uint8_t* data, size_t avail) {
const uint8_t* body;
// Skip frame header, hello header, protocol version and random data
size_t session_offset = body_offset_ + 4 + 2 + 32;
if (session_offset + 1 >= avail)
return false;
body = data + session_offset;
session_size_ = *body;
session_id_ = body + 1;
size_t cipher_offset = session_offset + 1 + session_size_;
// Session OOB failure
if (cipher_offset + 1 >= avail)
return false;
uint16_t cipher_len =
(data[cipher_offset] << 8) + data[cipher_offset + 1];
size_t comp_offset = cipher_offset + 2 + cipher_len;
// Cipher OOB failure
if (comp_offset >= avail)
return false;
uint8_t comp_len = data[comp_offset];
size_t extension_offset = comp_offset + 1 + comp_len;
// Compression OOB failure
if (extension_offset > avail)
return false;
// No extensions present
if (extension_offset == avail)
return true;
size_t ext_off = extension_offset + 2;
// Parse known extensions
while (ext_off < avail) {
// Extension OOB
if (ext_off + 4 > avail)
return false;
uint16_t ext_type = (data[ext_off] << 8) + data[ext_off + 1];
uint16_t ext_len = (data[ext_off + 2] << 8) + data[ext_off + 3];
ext_off += 4;
// Extension OOB
if (ext_off + ext_len > avail)
return false;
ParseExtension(ext_type,
data + ext_off,
ext_len);
ext_off += ext_len;
}
// Extensions OOB failure
if (ext_off > avail)
return false;
return true;
}
} // namespace node