mirror of
https://git.tartarus.org/simon/putty.git
synced 2025-01-10 01:48:00 +00:00
5087792440
The upcoming PRNG revamp will want to tell noise sources apart, so that it can treat them all fairly. So I've added an extra parameter to noise_ultralight and random_add_noise, which takes values in an enumeration covering all the vague classes of entropy source I'm collecting. In this commit, though, it's simply ignored.
148 lines
3.2 KiB
C
148 lines
3.2 KiB
C
/*
|
|
* Noise generation for PuTTY's cryptographic random number
|
|
* generator.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <errno.h>
|
|
|
|
#include <fcntl.h>
|
|
#include <unistd.h>
|
|
#include <sys/time.h>
|
|
#include <sys/resource.h>
|
|
|
|
#include "putty.h"
|
|
#include "ssh.h"
|
|
#include "storage.h"
|
|
|
|
static bool read_dev_urandom(char *buf, int len)
|
|
{
|
|
int fd;
|
|
int ngot, ret;
|
|
|
|
fd = open("/dev/urandom", O_RDONLY);
|
|
if (fd < 0)
|
|
return false;
|
|
|
|
ngot = 0;
|
|
while (ngot < len) {
|
|
ret = read(fd, buf+ngot, len-ngot);
|
|
if (ret < 0) {
|
|
close(fd);
|
|
return false;
|
|
}
|
|
ngot += ret;
|
|
}
|
|
|
|
close(fd);
|
|
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* This function is called once, at PuTTY startup. It will do some
|
|
* slightly silly things such as fetching an entire process listing
|
|
* and scanning /tmp, load the saved random seed from disk, and
|
|
* also read 32 bytes out of /dev/urandom.
|
|
*/
|
|
|
|
void noise_get_heavy(void (*func) (void *, int))
|
|
{
|
|
char buf[512];
|
|
FILE *fp;
|
|
int ret;
|
|
bool got_dev_urandom = false;
|
|
|
|
if (read_dev_urandom(buf, 32)) {
|
|
got_dev_urandom = true;
|
|
func(buf, 32);
|
|
}
|
|
|
|
fp = popen("ps -axu 2>/dev/null", "r");
|
|
if (fp) {
|
|
while ( (ret = fread(buf, 1, sizeof(buf), fp)) > 0)
|
|
func(buf, ret);
|
|
pclose(fp);
|
|
} else if (!got_dev_urandom) {
|
|
fprintf(stderr, "popen: %s\n"
|
|
"Unable to access fallback entropy source\n", strerror(errno));
|
|
exit(1);
|
|
}
|
|
|
|
fp = popen("ls -al /tmp 2>/dev/null", "r");
|
|
if (fp) {
|
|
while ( (ret = fread(buf, 1, sizeof(buf), fp)) > 0)
|
|
func(buf, ret);
|
|
pclose(fp);
|
|
} else if (!got_dev_urandom) {
|
|
fprintf(stderr, "popen: %s\n"
|
|
"Unable to access fallback entropy source\n", strerror(errno));
|
|
exit(1);
|
|
}
|
|
|
|
read_random_seed(func);
|
|
random_save_seed();
|
|
}
|
|
|
|
void random_save_seed(void)
|
|
{
|
|
int len;
|
|
void *data;
|
|
|
|
if (random_active) {
|
|
random_get_savedata(&data, &len);
|
|
write_random_seed(data, len);
|
|
sfree(data);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This function is called every time the random pool needs
|
|
* stirring, and will acquire the system time.
|
|
*/
|
|
void noise_get_light(void (*func) (void *, int))
|
|
{
|
|
struct timeval tv;
|
|
gettimeofday(&tv, NULL);
|
|
func(&tv, sizeof(tv));
|
|
}
|
|
|
|
/*
|
|
* This function is called on a timer, and grabs as much changeable
|
|
* system data as it can quickly get its hands on.
|
|
*/
|
|
void noise_regular(void)
|
|
{
|
|
int fd;
|
|
int ret;
|
|
char buf[512];
|
|
struct rusage rusage;
|
|
|
|
if ((fd = open("/proc/meminfo", O_RDONLY)) >= 0) {
|
|
while ( (ret = read(fd, buf, sizeof(buf))) > 0)
|
|
random_add_noise(NOISE_SOURCE_MEMINFO, buf, ret);
|
|
close(fd);
|
|
}
|
|
if ((fd = open("/proc/stat", O_RDONLY)) >= 0) {
|
|
while ( (ret = read(fd, buf, sizeof(buf))) > 0)
|
|
random_add_noise(NOISE_SOURCE_STAT, buf, ret);
|
|
close(fd);
|
|
}
|
|
getrusage(RUSAGE_SELF, &rusage);
|
|
random_add_noise(NOISE_SOURCE_RUSAGE, &rusage, sizeof(rusage));
|
|
}
|
|
|
|
/*
|
|
* This function is called on every keypress or mouse move, and
|
|
* will add the current time to the noise pool. It gets the scan
|
|
* code or mouse position passed in, and adds that too.
|
|
*/
|
|
void noise_ultralight(NoiseSourceId id, unsigned long data)
|
|
{
|
|
struct timeval tv;
|
|
gettimeofday(&tv, NULL);
|
|
random_add_noise(NOISE_SOURCE_TIME, &tv, sizeof(tv));
|
|
random_add_noise(id, &data, sizeof(data));
|
|
}
|