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#include <arpa/inet.h>
#include <string>
#include <vector>
#include <map>
#include <sys/time.h>
#include <stdio.h>
#include <signal.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "error.h"
#include "random_source.h"
#include "kernel_prng_io.h"
#include "utils.h"
#include "log.h"
#include "encrypt_stream.h"
#include "hasher.h"
#include "math.h"
#include "protocol.h"
#include "statistics.h"
#include "statistics_global.h"
#include "statistics_user.h"
#include "users.h"
#include "auth.h"
#define DEFAULT_COMM_TO 15
const char *pid_file = PID_DIR "/client_linux_kernel.pid";
const char *client_type = "client_linux_kernel " VERSION;
bool do_exit = false;
void sig_handler(int sig)
{
fprintf(stderr, "Exit due to signal %d\n", sig);
do_exit = true;
}
void help(void)
{
printf("-I host entropy_broker host to connect to\n");
printf(" e.g. host\n");
printf(" host:port\n");
printf(" [ipv6 literal]:port\n");
printf(" you can have multiple entries of this\n");
printf("-l file log to file 'file'\n");
printf("-L x log level, 0=nothing, 255=all\n");
printf("-s log to syslog\n");
printf("-b x interval in which data will be seeded in a full(!) kernel entropy buffer (default is off)\n");
printf("-n do not fork\n");
printf("-P file write pid to file\n");
printf("-X file read username+password from file\n");
}
int main(int argc, char *argv[])
{
int dev_random_fd = open(DEV_RANDOM, O_RDWR);
int max_bits_in_kernel_rng = kernel_rng_get_max_entropy_count();
int c;
bool do_not_fork = false, log_console = false, log_syslog = false;
char *log_logfile = NULL;
std::string username, password;
int interval = -1;
std::vector<std::string> hosts;
int log_level = LOG_INFO;
printf("eb_client_linux_kernel v" VERSION ", (C) 2009-2015 by folkert@vanheusden.com\n");
while((c = getopt(argc, argv, "b:hX:P:I:L:l:sn")) != -1)
{
switch(c)
{
case 'b':
interval = atoi(optarg);
if (interval < 1)
error_exit("Interval must be > 0");
break;
case 'X':
get_auth_from_file(optarg, username, password);
break;
case 'P':
pid_file = optarg;
break;
case 'I':
hosts.push_back(optarg);
break;
case 's':
log_syslog = true;
break;
case 'L':
log_level = atoi(optarg);
break;
case 'l':
log_logfile = optarg;
break;
case 'n':
do_not_fork = true;
log_console = true;
break;
default:
help();
return 1;
}
}
if (username.length() == 0 || password.length() == 0)
error_exit("please select a file with authentication parameters (username + password) using the -X switch");
if (hosts.empty())
error_exit("no host to connect to selected");
set_logging_parameters(log_console, log_logfile, log_syslog, log_level);
if (!do_not_fork)
{
if (daemon(0, 0) == -1)
error_exit("fork failed");
}
protocol *p = new protocol(&hosts, username, password, false, client_type, DEFAULT_COMM_TO);
(void)umask(0177);
no_core();
write_pid(pid_file);
signal(SIGPIPE, SIG_IGN);
signal(SIGTERM, sig_handler);
signal(SIGINT , sig_handler);
signal(SIGQUIT, sig_handler);
dolog(LOG_INFO, "started with %d bits in kernel rng", kernel_rng_get_entropy_count());
if (dev_random_fd == -1)
error_exit("failed to open %s", DEV_RANDOM);
bit_count_estimator bce(BCE_SHANNON);
for(;!do_exit;)
{
struct timeval tv, *ptv = NULL;
if (interval > 0)
{
tv.tv_sec = interval;
tv.tv_usec = 0;
ptv = &tv;
}
// wait for /dev/random te become writable which means the entropy-
// level dropped below a certain threshold
fd_set write_fd;
FD_ZERO(&write_fd);
FD_SET(dev_random_fd, &write_fd);
dolog(LOG_DEBUG, "wait for low-event");
for(;!do_exit;)
{
int rc = select(dev_random_fd + 1, NULL, &write_fd, NULL, ptv);
if (rc > 0) break;
if (rc == 0 && interval> 0) break;
if (errno != EINTR && errno != EAGAIN)
error_exit("Select error: %m");
}
if (do_exit)
break;
int n_bits_in_kernel_rng = kernel_rng_get_entropy_count();
dolog(LOG_DEBUG, "kernel rng bit count: %d", n_bits_in_kernel_rng);
if (FD_ISSET(dev_random_fd, &write_fd) || interval > 0)
{
/* find out how many bits to add */
int n_bits_to_get = max_bits_in_kernel_rng - n_bits_in_kernel_rng;
if (n_bits_to_get <= 0)
{
dolog(LOG_DEBUG, "number of bits to get <= 0: %d", n_bits_to_get);
continue;
}
if (n_bits_to_get > 9999)
n_bits_to_get = 9999;
if (n_bits_to_get < 8)
n_bits_to_get = 8;
dolog(LOG_INFO, "%d bits left (%d max), will get %d bits", n_bits_in_kernel_rng, max_bits_in_kernel_rng, n_bits_to_get);
int n_bytes_to_get = (n_bits_to_get + 7) / 8;
unsigned char *buffer = static_cast<unsigned char *>(malloc(n_bytes_to_get));
if (!buffer)
error_exit("out of memory allocating %d bytes", n_bytes_to_get);
lock_mem(buffer, n_bytes_to_get);
int n_bytes = p -> request_bytes(buffer, n_bits_to_get, false, &do_exit);
if (do_exit)
break;
int is_n_bits = bce.get_bit_count(reinterpret_cast<unsigned char *>(buffer), n_bytes);
int rc = kernel_rng_add_entropy(reinterpret_cast<unsigned char *>(buffer), n_bytes, is_n_bits);
if (rc == -1)
error_exit("error submiting entropy data to kernel");
dolog(LOG_DEBUG, "new entropy count: %d", kernel_rng_get_entropy_count());
memset(buffer, 0x00, n_bytes_to_get);
unlock_mem(buffer, n_bytes_to_get);
free(buffer);
}
}
unlink(pid_file);
delete p;
return 0;
}
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