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/*************************************************
* EGD EntropySource Source File *
* (C) 1999-2007 The Botan Project *
*************************************************/
#include <botan/es_egd.h>
#include <botan/config.h>
#include <botan/bit_ops.h>
#include <botan/parsing.h>
#include <cstring>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>
#ifndef PF_LOCAL
#define PF_LOCAL PF_UNIX
#endif
namespace Botan {
/*************************************************
* EGD_EntropySource Constructor *
*************************************************/
EGD_EntropySource::EGD_EntropySource(const std::string& egd_paths)
{
std::vector<std::string> path_list = split_on(egd_paths, ':');
std::vector<std::string> defaults =
global_config().option_as_list("rng/egd_path");
for(u32bit j = 0; j != path_list.size(); j++)
paths.push_back(path_list[j]);
for(u32bit j = 0; j != defaults.size(); j++)
paths.push_back(defaults[j]);
}
/*************************************************
* Gather Entropy from EGD *
*************************************************/
u32bit EGD_EntropySource::do_poll(byte output[], u32bit length,
const std::string& path) const
{
if(length > 128)
length = 128;
sockaddr_un addr;
std::memset(&addr, 0, sizeof(addr));
addr.sun_family = PF_LOCAL;
if(sizeof(addr.sun_path) < path.length() + 1)
throw Exception("EGD_EntropySource: Socket path is too long");
std::strcpy(addr.sun_path, path.c_str());
int fd = socket(addr.sun_family, SOCK_STREAM, 0);
if(fd == -1) return 0;
int len = sizeof(addr.sun_family) + std::strlen(addr.sun_path) + 1;
if(connect(fd, (struct sockaddr*)&addr, len))
{ close(fd); return 0; }
byte buffer[2];
buffer[0] = 1;
buffer[1] = static_cast<byte>(length);
if(write(fd, buffer, 2) != 2) { close(fd); return 0; }
if(read(fd, buffer, 1) != 1) { close(fd); return 0; }
ssize_t count = read(fd, output, buffer[0]);
if(count == -1) { close(fd); return 0; }
close(fd);
return count;
}
/*************************************************
* Gather Entropy from EGD *
*************************************************/
u32bit EGD_EntropySource::slow_poll(byte output[], u32bit length)
{
for(u32bit j = 0; j != paths.size(); j++)
{
u32bit got = do_poll(output, length, paths[j]);
if(got)
return got;
}
return 0;
}
}
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