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
|
/*
* Copyright 2004 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef _WEBRTC_BASE_CRYPTSTRING_H_
#define _WEBRTC_BASE_CRYPTSTRING_H_
#include <string.h>
#include <memory>
#include <string>
#include <vector>
namespace rtc {
class CryptStringImpl {
public:
virtual ~CryptStringImpl() {}
virtual size_t GetLength() const = 0;
virtual void CopyTo(char * dest, bool nullterminate) const = 0;
virtual std::string UrlEncode() const = 0;
virtual CryptStringImpl * Copy() const = 0;
virtual void CopyRawTo(std::vector<unsigned char> * dest) const = 0;
};
class EmptyCryptStringImpl : public CryptStringImpl {
public:
~EmptyCryptStringImpl() override {}
size_t GetLength() const override;
void CopyTo(char* dest, bool nullterminate) const override;
std::string UrlEncode() const override;
CryptStringImpl* Copy() const override;
void CopyRawTo(std::vector<unsigned char>* dest) const override;
};
class CryptString {
public:
CryptString();
size_t GetLength() const { return impl_->GetLength(); }
void CopyTo(char * dest, bool nullterminate) const { impl_->CopyTo(dest, nullterminate); }
CryptString(const CryptString& other);
explicit CryptString(const CryptStringImpl& impl);
~CryptString();
CryptString & operator=(const CryptString & other) {
if (this != &other) {
impl_.reset(other.impl_->Copy());
}
return *this;
}
void Clear() { impl_.reset(new EmptyCryptStringImpl()); }
std::string UrlEncode() const { return impl_->UrlEncode(); }
void CopyRawTo(std::vector<unsigned char> * dest) const {
return impl_->CopyRawTo(dest);
}
private:
std::unique_ptr<const CryptStringImpl> impl_;
};
// Used for constructing strings where a password is involved and we
// need to ensure that we zero memory afterwards
class FormatCryptString {
public:
FormatCryptString() {
storage_ = new char[32];
capacity_ = 32;
length_ = 0;
storage_[0] = 0;
}
void Append(const std::string & text) {
Append(text.data(), text.length());
}
void Append(const char * data, size_t length) {
EnsureStorage(length_ + length + 1);
memcpy(storage_ + length_, data, length);
length_ += length;
storage_[length_] = '\0';
}
void Append(const CryptString * password) {
size_t len = password->GetLength();
EnsureStorage(length_ + len + 1);
password->CopyTo(storage_ + length_, true);
length_ += len;
}
size_t GetLength() {
return length_;
}
const char * GetData() {
return storage_;
}
// Ensures storage of at least n bytes
void EnsureStorage(size_t n) {
if (capacity_ >= n) {
return;
}
size_t old_capacity = capacity_;
char * old_storage = storage_;
for (;;) {
capacity_ *= 2;
if (capacity_ >= n)
break;
}
storage_ = new char[capacity_];
if (old_capacity) {
memcpy(storage_, old_storage, length_);
// zero memory in a way that an optimizer won't optimize it out
old_storage[0] = 0;
for (size_t i = 1; i < old_capacity; i++) {
old_storage[i] = old_storage[i - 1];
}
delete[] old_storage;
}
}
~FormatCryptString() {
if (capacity_) {
storage_[0] = 0;
for (size_t i = 1; i < capacity_; i++) {
storage_[i] = storage_[i - 1];
}
}
delete[] storage_;
}
private:
char * storage_;
size_t capacity_;
size_t length_;
};
class InsecureCryptStringImpl : public CryptStringImpl {
public:
std::string& password() { return password_; }
const std::string& password() const { return password_; }
~InsecureCryptStringImpl() override = default;
size_t GetLength() const override;
void CopyTo(char* dest, bool nullterminate) const override;
std::string UrlEncode() const override;
CryptStringImpl* Copy() const override;
void CopyRawTo(std::vector<unsigned char>* dest) const override;
private:
std::string password_;
};
}
#endif // _WEBRTC_BASE_CRYPTSTRING_H_
|
