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
|
/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of Qt Creator.
**
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia. For licensing terms and
** conditions see http://qt.digia.com/licensing. For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
****************************************************************************/
#include "sshkeyexchange_p.h"
#include "sshbotanconversions_p.h"
#include "sshcapabilities_p.h"
#include "sshsendfacility_p.h"
#include "sshexception_p.h"
#include "sshincomingpacket_p.h"
#include <botan/botan.h>
#ifdef CREATOR_SSH_DEBUG
#include <iostream>
#endif
#include <string>
using namespace Botan;
namespace QSsh {
namespace Internal {
namespace {
// For debugging
void printNameList(const char *listName, const SshNameList &list)
{
#ifdef CREATOR_SSH_DEBUG
qDebug("%s:", listName);
foreach (const QByteArray &name, list.names)
qDebug("%s", name.constData());
#else
Q_UNUSED(listName);
Q_UNUSED(list);
#endif
}
#ifdef CREATOR_SSH_DEBUG
void printData(const char *name, const QByteArray &data)
{
std::cerr << std::hex;
qDebug("The client thinks the %s has length %d and is:", name, data.count());
for (int i = 0; i < data.count(); ++i)
std::cerr << (static_cast<unsigned int>(data.at(i)) & 0xff) << ' ';
std::cerr << std::endl;
}
#endif
} // anonymous namespace
SshKeyExchange::SshKeyExchange(SshSendFacility &sendFacility)
: m_sendFacility(sendFacility)
{
}
SshKeyExchange::~SshKeyExchange() {}
void SshKeyExchange::sendKexInitPacket(const QByteArray &serverId)
{
m_serverId = serverId;
m_clientKexInitPayload = m_sendFacility.sendKeyExchangeInitPacket();
}
bool SshKeyExchange::sendDhInitPacket(const SshIncomingPacket &serverKexInit)
{
#ifdef CREATOR_SSH_DEBUG
qDebug("server requests key exchange");
#endif
serverKexInit.printRawBytes();
SshKeyExchangeInit kexInitParams
= serverKexInit.extractKeyExchangeInitData();
printNameList("Key Algorithms", kexInitParams.keyAlgorithms);
printNameList("Server Host Key Algorithms", kexInitParams.serverHostKeyAlgorithms);
printNameList("Encryption algorithms client to server", kexInitParams.encryptionAlgorithmsClientToServer);
printNameList("Encryption algorithms server to client", kexInitParams.encryptionAlgorithmsServerToClient);
printNameList("MAC algorithms client to server", kexInitParams.macAlgorithmsClientToServer);
printNameList("MAC algorithms server to client", kexInitParams.macAlgorithmsServerToClient);
printNameList("Compression algorithms client to server", kexInitParams.compressionAlgorithmsClientToServer);
printNameList("Compression algorithms client to server", kexInitParams.compressionAlgorithmsClientToServer);
printNameList("Languages client to server", kexInitParams.languagesClientToServer);
printNameList("Languages server to client", kexInitParams.languagesServerToClient);
#ifdef CREATOR_SSH_DEBUG
qDebug("First packet follows: %d", kexInitParams.firstKexPacketFollows);
#endif
const QByteArray &keyAlgo
= SshCapabilities::findBestMatch(SshCapabilities::KeyExchangeMethods,
kexInitParams.keyAlgorithms.names);
m_serverHostKeyAlgo
= SshCapabilities::findBestMatch(SshCapabilities::PublicKeyAlgorithms,
kexInitParams.serverHostKeyAlgorithms.names);
m_encryptionAlgo
= SshCapabilities::findBestMatch(SshCapabilities::EncryptionAlgorithms,
kexInitParams.encryptionAlgorithmsClientToServer.names);
m_decryptionAlgo
= SshCapabilities::findBestMatch(SshCapabilities::EncryptionAlgorithms,
kexInitParams.encryptionAlgorithmsServerToClient.names);
m_c2sHMacAlgo
= SshCapabilities::findBestMatch(SshCapabilities::MacAlgorithms,
kexInitParams.macAlgorithmsClientToServer.names);
m_s2cHMacAlgo
= SshCapabilities::findBestMatch(SshCapabilities::MacAlgorithms,
kexInitParams.macAlgorithmsServerToClient.names);
SshCapabilities::findBestMatch(SshCapabilities::CompressionAlgorithms,
kexInitParams.compressionAlgorithmsClientToServer.names);
SshCapabilities::findBestMatch(SshCapabilities::CompressionAlgorithms,
kexInitParams.compressionAlgorithmsServerToClient.names);
AutoSeeded_RNG rng;
m_dhKey = createDhPrivateKey(rng, DL_Group(botanKeyExchangeAlgoName(keyAlgo)));
m_serverKexInitPayload = serverKexInit.payLoad();
m_sendFacility.sendKeyDhInitPacket(m_dhKey->get_y());
return kexInitParams.firstKexPacketFollows;
}
void SshKeyExchange::sendNewKeysPacket(const SshIncomingPacket &dhReply,
const QByteArray &clientId)
{
const SshKeyExchangeReply &reply
= dhReply.extractKeyExchangeReply(m_serverHostKeyAlgo);
if (reply.f <= 0 || reply.f >= m_dhKey->group_p()) {
throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
"Server sent invalid f.");
}
QByteArray concatenatedData = AbstractSshPacket::encodeString(clientId);
concatenatedData += AbstractSshPacket::encodeString(m_serverId);
concatenatedData += AbstractSshPacket::encodeString(m_clientKexInitPayload);
concatenatedData += AbstractSshPacket::encodeString(m_serverKexInitPayload);
concatenatedData += reply.k_s;
concatenatedData += AbstractSshPacket::encodeMpInt(m_dhKey->get_y());
concatenatedData += AbstractSshPacket::encodeMpInt(reply.f);
const BigInt k = power_mod(reply.f, m_dhKey->get_x(), m_dhKey->get_domain().get_p());
m_k = AbstractSshPacket::encodeMpInt(k);
concatenatedData += m_k;
m_hash.reset(get_hash(botanSha1Name()));
const SecureVector<byte> &hashResult
= m_hash->process(convertByteArray(concatenatedData),
concatenatedData.size());
m_h = convertByteArray(hashResult);
#ifdef CREATOR_SSH_DEBUG
printData("Client Id", AbstractSshPacket::encodeString(clientId));
printData("Server Id", AbstractSshPacket::encodeString(m_serverId));
printData("Client Payload", AbstractSshPacket::encodeString(m_clientKexInitPayload));
printData("Server payload", AbstractSshPacket::encodeString(m_serverKexInitPayload));
printData("K_S", reply.k_s);
printData("y", AbstractSshPacket::encodeMpInt(m_dhKey->get_y()));
printData("f", AbstractSshPacket::encodeMpInt(reply.f));
printData("K", m_k);
printData("Concatenated data", concatenatedData);
printData("H", m_h);
#endif // CREATOR_SSH_DEBUG
QSharedPointer<Public_Key> publicKey;
QByteArray algorithm;
if (m_serverHostKeyAlgo == SshCapabilities::PubKeyDss) {
const DL_Group group(reply.parameters.at(0), reply.parameters.at(1),
reply.parameters.at(2));
publicKey = createDsaPublicKey(group, reply.parameters.at(3));
algorithm = SshCapabilities::PubKeyDss;
} else if (m_serverHostKeyAlgo == SshCapabilities::PubKeyRsa) {
publicKey = createRsaPublicKey(reply.parameters.at(1), reply.parameters.at(0));
algorithm = SshCapabilities::PubKeyRsa;
} else {
Q_ASSERT(!"Impossible: Neither DSS nor RSA!");
}
const byte * const botanH = convertByteArray(m_h);
const Botan::byte * const botanSig
= convertByteArray(reply.signatureBlob);
if (!PK_Verifier(*publicKey, botanEmsaAlgoName(algorithm)).verify_message(botanH, m_h.size(),
botanSig, reply.signatureBlob.size())) {
throw SSH_SERVER_EXCEPTION(SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
"Invalid signature in SSH_MSG_KEXDH_REPLY packet.");
}
m_sendFacility.sendNewKeysPacket();
}
} // namespace Internal
} // namespace QSsh
|
