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
212
|
/*
* DataSource
* (C) 1999-2007 Jack Lloyd
* 2005 Matthew Gregan
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/data_src.h>
#include <botan/exceptn.h>
#include <fstream>
#include <algorithm>
namespace Botan {
/*
* Read a single byte from the DataSource
*/
size_t DataSource::read_byte(byte& out)
{
return read(&out, 1);
}
/*
* Peek a single byte from the DataSource
*/
size_t DataSource::peek_byte(byte& out) const
{
return peek(&out, 1, 0);
}
/*
* Discard the next N bytes of the data
*/
size_t DataSource::discard_next(size_t n)
{
byte buf[64] = { 0 };
size_t discarded = 0;
while(n)
{
const size_t got = this->read(buf, std::min(n, sizeof(buf)));
discarded += got;
n -= got;
if(got == 0)
break;
}
return discarded;
}
/*
* Read from a memory buffer
*/
size_t DataSource_Memory::read(byte out[], size_t length)
{
size_t got = std::min<size_t>(m_source.size() - m_offset, length);
copy_mem(out, m_source.data() + m_offset, got);
m_offset += got;
return got;
}
bool DataSource_Memory::check_available(size_t n)
{
return (n <= (m_source.size() - m_offset));
}
/*
* Peek into a memory buffer
*/
size_t DataSource_Memory::peek(byte out[], size_t length,
size_t peek_offset) const
{
const size_t bytes_left = m_source.size() - m_offset;
if(peek_offset >= bytes_left) return 0;
size_t got = std::min(bytes_left - peek_offset, length);
copy_mem(out, &m_source[m_offset + peek_offset], got);
return got;
}
/*
* Check if the memory buffer is empty
*/
bool DataSource_Memory::end_of_data() const
{
return (m_offset == m_source.size());
}
/*
* DataSource_Memory Constructor
*/
DataSource_Memory::DataSource_Memory(const std::string& in) :
m_source(reinterpret_cast<const byte*>(in.data()),
reinterpret_cast<const byte*>(in.data()) + in.length()),
m_offset(0)
{
}
/*
* Read from a stream
*/
size_t DataSource_Stream::read(byte out[], size_t length)
{
m_source.read(reinterpret_cast<char*>(out), length);
if(m_source.bad())
throw Stream_IO_Error("DataSource_Stream::read: Source failure");
size_t got = m_source.gcount();
m_total_read += got;
return got;
}
bool DataSource_Stream::check_available(size_t n)
{
const std::streampos orig_pos = m_source.tellg();
m_source.seekg(0, std::ios::end);
const size_t avail = m_source.tellg() - orig_pos;
m_source.seekg(orig_pos);
return (avail >= n);
}
/*
* Peek into a stream
*/
size_t DataSource_Stream::peek(byte out[], size_t length, size_t offset) const
{
if(end_of_data())
throw Invalid_State("DataSource_Stream: Cannot peek when out of data");
size_t got = 0;
if(offset)
{
secure_vector<byte> buf(offset);
m_source.read(reinterpret_cast<char*>(buf.data()), buf.size());
if(m_source.bad())
throw Stream_IO_Error("DataSource_Stream::peek: Source failure");
got = m_source.gcount();
}
if(got == offset)
{
m_source.read(reinterpret_cast<char*>(out), length);
if(m_source.bad())
throw Stream_IO_Error("DataSource_Stream::peek: Source failure");
got = m_source.gcount();
}
if(m_source.eof())
m_source.clear();
m_source.seekg(m_total_read, std::ios::beg);
return got;
}
/*
* Check if the stream is empty or in error
*/
bool DataSource_Stream::end_of_data() const
{
return (!m_source.good());
}
/*
* Return a human-readable ID for this stream
*/
std::string DataSource_Stream::id() const
{
return m_identifier;
}
/*
* DataSource_Stream Constructor
*/
DataSource_Stream::DataSource_Stream(const std::string& path,
bool use_binary) :
m_identifier(path),
m_source_p(new std::ifstream(path,
use_binary ? std::ios::binary : std::ios::in)),
m_source(*m_source_p),
m_total_read(0)
{
if(!m_source.good())
{
delete m_source_p;
throw Stream_IO_Error("DataSource: Failure opening file " + path);
}
}
/*
* DataSource_Stream Constructor
*/
DataSource_Stream::DataSource_Stream(std::istream& in,
const std::string& name) :
m_identifier(name),
m_source_p(nullptr),
m_source(in),
m_total_read(0)
{
}
/*
* DataSource_Stream Destructor
*/
DataSource_Stream::~DataSource_Stream()
{
delete m_source_p;
}
}
|
