blob: 53e39d834b72c55ef98187a76c7695e4f821e2b4 (
plain)
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
|
/*
* FTW EntropySource
* (C) 1999-2008 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/internal/es_ftw.h>
#include <botan/secmem.h>
#include <cstring>
#include <deque>
#ifndef _POSIX_C_SOURCE
#define _POSIX_C_SOURCE 199309
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <dirent.h>
#include <fcntl.h>
namespace Botan {
/**
* Returns file descriptors. Until it doesn't
*/
class File_Descriptor_Source
{
public:
/**
* @return next file descriptor, or -1 if done
*/
virtual int next_fd() = 0;
virtual ~File_Descriptor_Source() {}
};
namespace {
class Directory_Walker : public File_Descriptor_Source
{
public:
Directory_Walker(const std::string& root) { add_directory(root); }
~Directory_Walker();
int next_fd();
private:
void add_directory(const std::string&);
std::deque<std::pair<DIR*, std::string> > dirs;
};
void Directory_Walker::add_directory(const std::string& dirname)
{
DIR* dir = ::opendir(dirname.c_str());
if(dir)
dirs.push_back(std::make_pair(dir, dirname));
}
Directory_Walker::~Directory_Walker()
{
while(dirs.size())
{
::closedir(dirs[0].first);
dirs.pop_front();
}
}
int Directory_Walker::next_fd()
{
while(dirs.size())
{
std::pair<DIR*, std::string> dirinfo = dirs[0];
struct dirent* entry = ::readdir(dirinfo.first);
if(!entry)
{
::closedir(dirinfo.first);
dirs.pop_front();
continue;
}
const std::string filename = entry->d_name;
if(filename == "." || filename == "..")
continue;
const std::string full_path = dirinfo.second + '/' + filename;
struct stat stat_buf;
if(::lstat(full_path.c_str(), &stat_buf) == -1)
continue;
if(S_ISDIR(stat_buf.st_mode))
add_directory(full_path);
else if(S_ISREG(stat_buf.st_mode) && (stat_buf.st_mode & S_IROTH))
{
int fd = ::open(full_path.c_str(), O_RDONLY | O_NOCTTY);
if(fd > 0)
return fd;
}
}
return -1;
}
}
/**
* FTW_EntropySource Constructor
*/
FTW_EntropySource::FTW_EntropySource(const std::string& p) : path(p)
{
dir = 0;
}
/**
* FTW_EntropySource Destructor
*/
FTW_EntropySource::~FTW_EntropySource()
{
delete dir;
}
void FTW_EntropySource::poll(Entropy_Accumulator& accum)
{
const u32bit MAX_FILES_READ_PER_POLL = 1024;
if(!dir)
dir = new Directory_Walker(path);
MemoryRegion<byte>& io_buffer = accum.get_io_buffer(128);
for(u32bit i = 0; i != MAX_FILES_READ_PER_POLL; ++i)
{
int fd = dir->next_fd();
// If we've exhaused this walk of the directory, halt the poll
if(fd == -1)
{
delete dir;
dir = 0;
break;
}
ssize_t got = ::read(fd, io_buffer.begin(), io_buffer.size());
::close(fd);
if(got > 0)
accum.add(io_buffer.begin(), got, .01);
if(accum.polling_goal_achieved())
break;
}
}
}
|
