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
|
// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "remoting/protocol/negotiating_host_authenticator.h"
#include <algorithm>
#include <sstream>
#include "base/bind.h"
#include "base/callback.h"
#include "base/logging.h"
#include "base/strings/string_split.h"
#include "remoting/base/rsa_key_pair.h"
#include "remoting/protocol/channel_authenticator.h"
#include "remoting/protocol/v2_authenticator.h"
#include "third_party/libjingle/source/talk/xmllite/xmlelement.h"
namespace remoting {
namespace protocol {
NegotiatingHostAuthenticator::NegotiatingHostAuthenticator(
const std::string& local_cert,
scoped_refptr<RsaKeyPair> key_pair,
const std::string& shared_secret_hash,
AuthenticationMethod::HashFunction hash_function)
: NegotiatingAuthenticatorBase(WAITING_MESSAGE),
local_cert_(local_cert),
local_key_pair_(key_pair),
shared_secret_hash_(shared_secret_hash) {
AddMethod(AuthenticationMethod::Spake2(hash_function));
}
NegotiatingHostAuthenticator::~NegotiatingHostAuthenticator() {
}
void NegotiatingHostAuthenticator::ProcessMessage(
const buzz::XmlElement* message,
const base::Closure& resume_callback) {
DCHECK_EQ(state(), WAITING_MESSAGE);
std::string method_attr = message->Attr(kMethodAttributeQName);
AuthenticationMethod method = AuthenticationMethod::FromString(method_attr);
// If the host has already chosen a method, it can't be changed by the client.
if (current_method_.is_valid() && method != current_method_) {
state_ = REJECTED;
rejection_reason_ = PROTOCOL_ERROR;
resume_callback.Run();
return;
}
// If the client did not specify auth method or specified unknown method,
// then select the first known method from the supported-methods attribute.
if (!method.is_valid() ||
std::find(methods_.begin(), methods_.end(), method) == methods_.end()) {
method = AuthenticationMethod::Invalid();
std::string supported_methods_attr =
message->Attr(kSupportedMethodsAttributeQName);
if (supported_methods_attr.empty()) {
// Message contains neither method nor supported-methods attributes.
state_ = REJECTED;
rejection_reason_ = PROTOCOL_ERROR;
resume_callback.Run();
return;
}
// Find the first mutually-supported method in the client's list of
// supported-methods.
std::vector<std::string> supported_methods_strs;
base::SplitString(supported_methods_attr, kSupportedMethodsSeparator,
&supported_methods_strs);
for (std::vector<std::string>::iterator it = supported_methods_strs.begin();
it != supported_methods_strs.end(); ++it) {
AuthenticationMethod list_value = AuthenticationMethod::FromString(*it);
if (list_value.is_valid() &&
std::find(methods_.begin(),
methods_.end(), list_value) != methods_.end()) {
// Found common method.
method = list_value;
break;
}
}
if (!method.is_valid()) {
// Failed to find a common auth method.
state_ = REJECTED;
rejection_reason_ = PROTOCOL_ERROR;
resume_callback.Run();
return;
}
// Drop the current message because we've chosen a different method.
current_method_ = method;
state_ = PROCESSING_MESSAGE;
CreateAuthenticator(MESSAGE_READY, base::Bind(
&NegotiatingHostAuthenticator::UpdateState,
base::Unretained(this), resume_callback));
return;
}
// If the client specified a supported method, and the host hasn't chosen a
// method yet, use the client's preferred method and process the message.
if (!current_method_.is_valid()) {
current_method_ = method;
state_ = PROCESSING_MESSAGE;
// Copy the message since the authenticator may process it asynchronously.
CreateAuthenticator(WAITING_MESSAGE, base::Bind(
&NegotiatingAuthenticatorBase::ProcessMessageInternal,
base::Unretained(this), base::Owned(new buzz::XmlElement(*message)),
resume_callback));
return;
}
// If the client is using the host's current method, just process the message.
ProcessMessageInternal(message, resume_callback);
}
scoped_ptr<buzz::XmlElement> NegotiatingHostAuthenticator::GetNextMessage() {
return GetNextMessageInternal();
}
void NegotiatingHostAuthenticator::CreateAuthenticator(
Authenticator::State preferred_initial_state,
const base::Closure& resume_callback) {
current_authenticator_ = V2Authenticator::CreateForHost(
local_cert_, local_key_pair_, shared_secret_hash_,
preferred_initial_state);
resume_callback.Run();
}
} // namespace protocol
} // namespace remoting
|
