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
|
/*
* SecureQueue
* (C) 1999-2007 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/secqueue.h>
#include <algorithm>
namespace Botan {
/*
* SecureQueueNode
*/
class SecureQueueNode
{
public:
u32bit write(const byte input[], u32bit length)
{
u32bit copied = std::min(length, buffer.size() - end);
copy_mem(buffer + end, input, copied);
end += copied;
return copied;
}
u32bit read(byte output[], u32bit length)
{
u32bit copied = std::min(length, end - start);
copy_mem(output, buffer + start, copied);
start += copied;
return copied;
}
u32bit peek(byte output[], u32bit length, u32bit offset = 0)
{
const u32bit left = end - start;
if(offset >= left) return 0;
u32bit copied = std::min(length, left - offset);
copy_mem(output, buffer + start + offset, copied);
return copied;
}
u32bit size() const { return (end - start); }
SecureQueueNode() { next = 0; start = end = 0; }
~SecureQueueNode() { next = 0; start = end = 0; }
private:
friend class SecureQueue;
SecureQueueNode* next;
SecureBuffer<byte, DEFAULT_BUFFERSIZE> buffer;
u32bit start, end;
};
/*
* Create a SecureQueue
*/
SecureQueue::SecureQueue()
{
set_next(0, 0);
head = tail = new SecureQueueNode;
}
/*
* Copy a SecureQueue
*/
SecureQueue::SecureQueue(const SecureQueue& input) :
Fanout_Filter(), DataSource()
{
set_next(0, 0);
head = tail = new SecureQueueNode;
SecureQueueNode* temp = input.head;
while(temp)
{
write(temp->buffer + temp->start, temp->end - temp->start);
temp = temp->next;
}
}
/*
* Destroy this SecureQueue
*/
void SecureQueue::destroy()
{
SecureQueueNode* temp = head;
while(temp)
{
SecureQueueNode* holder = temp->next;
delete temp;
temp = holder;
}
head = tail = 0;
}
/*
* Copy a SecureQueue
*/
SecureQueue& SecureQueue::operator=(const SecureQueue& input)
{
destroy();
head = tail = new SecureQueueNode;
SecureQueueNode* temp = input.head;
while(temp)
{
write(temp->buffer + temp->start, temp->end - temp->start);
temp = temp->next;
}
return (*this);
}
/*
* Add some bytes to the queue
*/
void SecureQueue::write(const byte input[], u32bit length)
{
if(!head)
head = tail = new SecureQueueNode;
while(length)
{
const u32bit n = tail->write(input, length);
input += n;
length -= n;
if(length)
{
tail->next = new SecureQueueNode;
tail = tail->next;
}
}
}
/*
* Read some bytes from the queue
*/
u32bit SecureQueue::read(byte output[], u32bit length)
{
u32bit got = 0;
while(length && head)
{
const u32bit n = head->read(output, length);
output += n;
got += n;
length -= n;
if(head->size() == 0)
{
SecureQueueNode* holder = head->next;
delete head;
head = holder;
}
}
return got;
}
/*
* Read data, but do not remove it from queue
*/
u32bit SecureQueue::peek(byte output[], u32bit length, u32bit offset) const
{
SecureQueueNode* current = head;
while(offset && current)
{
if(offset >= current->size())
{
offset -= current->size();
current = current->next;
}
else
break;
}
u32bit got = 0;
while(length && current)
{
const u32bit n = current->peek(output, length, offset);
offset = 0;
output += n;
got += n;
length -= n;
current = current->next;
}
return got;
}
/*
* Return how many bytes the queue holds
*/
u32bit SecureQueue::size() const
{
SecureQueueNode* current = head;
u32bit count = 0;
while(current)
{
count += current->size();
current = current->next;
}
return count;
}
/*
* Test if the queue has any data in it
*/
bool SecureQueue::end_of_data() const
{
return (size() == 0);
}
}
|
