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
|
/*
* Copyright (c) 2020, Ali Mohammad Pur <ali.mpfard@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/Random.h>
#include <LibCrypto/ASN1/DER.h>
#include <LibCrypto/PK/Code/EMSA_PSS.h>
#include <LibTLS/TLSv12.h>
namespace TLS {
ByteBuffer TLSv12::build_hello()
{
AK::fill_with_random(&m_context.local_random, 32);
auto packet_version = (u16)m_context.version;
auto version = (u16)m_context.version;
PacketBuilder builder { MessageType::Handshake, packet_version };
builder.append((u8)ClientHello);
// hello length (for later)
u8 dummy[3] = {};
builder.append(dummy, 3);
auto start_length = builder.length();
builder.append(version);
builder.append(m_context.local_random, sizeof(m_context.local_random));
builder.append(m_context.session_id_size);
if (m_context.session_id_size)
builder.append(m_context.session_id, m_context.session_id_size);
size_t extension_length = 0;
size_t alpn_length = 0;
size_t alpn_negotiated_length = 0;
// ALPN
if (!m_context.negotiated_alpn.is_null()) {
alpn_negotiated_length = m_context.negotiated_alpn.length();
alpn_length = alpn_negotiated_length + 1;
extension_length += alpn_length + 6;
} else if (m_context.alpn.size()) {
for (auto& alpn : m_context.alpn) {
size_t length = alpn.length();
alpn_length += length + 1;
}
if (alpn_length)
extension_length += alpn_length + 6;
}
// Ciphers
builder.append((u16)(5 * sizeof(u16)));
builder.append((u16)CipherSuite::RSA_WITH_AES_128_CBC_SHA256);
builder.append((u16)CipherSuite::RSA_WITH_AES_256_CBC_SHA256);
builder.append((u16)CipherSuite::RSA_WITH_AES_128_CBC_SHA);
builder.append((u16)CipherSuite::RSA_WITH_AES_256_CBC_SHA);
builder.append((u16)CipherSuite::RSA_WITH_AES_128_GCM_SHA256);
// we don't like compression
builder.append((u8)1);
builder.append((u8)0);
// set SNI if we have one
auto sni_length = 0;
if (!m_context.SNI.is_null())
sni_length = m_context.SNI.length();
if (sni_length)
extension_length += sni_length + 9;
builder.append((u16)extension_length);
if (sni_length) {
// SNI extension
builder.append((u16)HandshakeExtension::ServerName);
// extension length
builder.append((u16)(sni_length + 5));
// SNI length
builder.append((u16)(sni_length + 3));
// SNI type
builder.append((u8)0);
// SNI host length + value
builder.append((u16)sni_length);
builder.append((const u8*)m_context.SNI.characters(), sni_length);
}
if (alpn_length) {
// TODO
ASSERT_NOT_REACHED();
}
// set the "length" field of the packet
size_t remaining = builder.length() - start_length;
size_t payload_position = 6;
builder.set(payload_position, remaining / 0x10000);
remaining %= 0x10000;
builder.set(payload_position + 1, remaining / 0x100);
remaining %= 0x100;
builder.set(payload_position + 2, remaining);
auto packet = builder.build();
update_packet(packet);
return packet;
}
ByteBuffer TLSv12::build_alert(bool critical, u8 code)
{
PacketBuilder builder(MessageType::Alert, (u16)m_context.version);
builder.append((u8)(critical ? AlertLevel::Critical : AlertLevel::Warning));
builder.append(code);
if (critical)
m_context.critical_error = code;
auto packet = builder.build();
update_packet(packet);
return packet;
}
ByteBuffer TLSv12::build_finished()
{
PacketBuilder builder { MessageType::Handshake, m_context.version, 12 + 64 };
builder.append((u8)HandshakeType::Finished);
u32 out_size = 12;
builder.append_u24(out_size);
u8 out[out_size];
auto outbuffer = Bytes { out, out_size };
auto dummy = ByteBuffer::create_zeroed(0);
auto digest = m_context.handshake_hash.digest();
auto hashbuf = ReadonlyBytes { digest.immutable_data(), m_context.handshake_hash.digest_size() };
pseudorandom_function(outbuffer, m_context.master_key, (const u8*)"client finished", 15, hashbuf, dummy);
builder.append(outbuffer);
auto packet = builder.build();
update_packet(packet);
return packet;
}
void TLSv12::alert(AlertLevel level, AlertDescription code)
{
auto the_alert = build_alert(level == AlertLevel::Critical, (u8)code);
write_packet(the_alert);
flush();
}
}
|
