summaryrefslogtreecommitdiff
path: root/entropy.c
diff options
context:
space:
mode:
authorDamien Miller <djm@mindrot.org>2000-05-17 21:34:07 +1000
committerDamien Miller <djm@mindrot.org>2000-05-17 21:34:07 +1000
commit8d1fd57a971159c828ab778136ca6332f0ba8f34 (patch)
treeabf87d7010d72962088ba0e11f0d4f257e8c5a41 /entropy.c
parent95fe91bd84d7613ce37cb8b38212c4301610639f (diff)
- Fix from Andre Lucas <andre.lucas@dial.pipex.com>
- Fixes command line printing segfaults (spotter: Bladt Norbert) - Fixes erroneous printing of debug messages to syslog - Fixes utmp for MacOS X (spotter: Aristedes Maniatis) - Gives useful error message if PRNG initialisation fails - Reduced ssh startup delay - Measures cumulative command time rather than the time between reads after select() - 'fixprogs' perl script to eliminate non-working entropy commands, and optionally run 'ent' to measure command entropy
Diffstat (limited to 'entropy.c')
-rw-r--r--entropy.c79
1 files changed, 58 insertions, 21 deletions
diff --git a/entropy.c b/entropy.c
index 2a1db420..79ef93ac 100644
--- a/entropy.c
+++ b/entropy.c
@@ -35,7 +35,7 @@
#include <openssl/rand.h>
#include <openssl/sha.h>
-RCSID("$Id: entropy.c,v 1.9 2000/05/11 09:10:58 damien Exp $");
+RCSID("$Id: entropy.c,v 1.10 2000/05/17 11:34:08 damien Exp $");
#ifdef EGD_SOCKET
#ifndef offsetof
@@ -133,6 +133,8 @@ typedef struct
char *path;
/* argv to pass to executable */
char *args[5];
+ /* full command string (debug) */
+ char *cmdstring;
} entropy_source_t;
double stir_from_system(void);
@@ -211,8 +213,8 @@ stir_from_programs(void)
/* FIXME: turn this off later */
#if 1
- debug("Got %0.2f bytes of entropy from %s", entropy_estimate,
- entropy_sources[c].path);
+ debug("Got %0.2f bytes of entropy from '%s'", entropy_estimate,
+ entropy_sources[c].cmdstring);
#endif
total_entropy_estimate += entropy_estimate;
@@ -225,9 +227,8 @@ stir_from_programs(void)
} else {
/* FIXME: turn this off later */
#if 1
- debug("Command '%s %s %s' disabled (badness %d)",
- entropy_sources[c].path, entropy_sources[c].args[1],
- entropy_sources[c].args[2], entropy_sources[c].badness);
+ debug("Command '%s' disabled (badness %d)",
+ entropy_sources[c].cmdstring, entropy_sources[c].badness);
#endif
if (entropy_sources[c].badness > 0)
@@ -286,6 +287,17 @@ stir_rusage(int who, double entropy_estimate)
#endif /* _HAVE_GETRUSAGE */
}
+
+static
+int
+_get_timeval_msec_difference(struct timeval *t1, struct timeval *t2) {
+ int secdiff, usecdiff;
+
+ secdiff = t2->tv_sec - t1->tv_sec;
+ usecdiff = (secdiff*1000000) + (t2->tv_usec - t1->tv_usec);
+ return (int)(usecdiff / 1000);
+}
+
double
hash_output_from_command(entropy_source_t *src, char *hash)
{
@@ -293,9 +305,11 @@ hash_output_from_command(entropy_source_t *src, char *hash)
int p[2];
fd_set rdset;
int cmd_eof = 0, error_abort = 0;
+ struct timeval tv_start, tv_current;
+ int msec_elapsed = 0;
pid_t pid;
int status;
- char buf[2048];
+ char buf[16384];
int bytes_read;
int total_bytes_read;
SHA_CTX sha;
@@ -309,6 +323,8 @@ hash_output_from_command(entropy_source_t *src, char *hash)
if (pipe(p) == -1)
fatal("Couldn't open pipe: %s", strerror(errno));
+ (void)gettimeofday(&tv_start, NULL); /* record start time */
+
switch (pid = fork()) {
case -1: /* Error */
close(p[0]);
@@ -324,8 +340,8 @@ hash_output_from_command(entropy_source_t *src, char *hash)
close(devnull);
execv(src->path, (char**)(src->args));
- debug("(child) Couldn't exec '%s %s %s': %s", src->path,
- src->args[1], src->args[2], strerror(errno));
+ debug("(child) Couldn't exec '%s': %s", src->cmdstring,
+ strerror(errno));
src->badness = src->sticky_badness = 128;
_exit(-1);
default: /* Parent */
@@ -343,13 +359,24 @@ hash_output_from_command(entropy_source_t *src, char *hash)
while (!error_abort && !cmd_eof) {
int ret;
struct timeval tv;
+ int msec_remaining;
+
+ (void) gettimeofday(&tv_current, 0);
+ msec_elapsed = _get_timeval_msec_difference(
+ &tv_start, &tv_current);
+ if (msec_elapsed >= entropy_timeout_current) {
+ error_abort=1;
+ continue;
+ }
+ msec_remaining = entropy_timeout_current - msec_elapsed;
FD_ZERO(&rdset);
FD_SET(p[0], &rdset);
- tv.tv_sec = entropy_timeout_current / 1000;
- tv.tv_usec = (entropy_timeout_current % 1000) * 1000;
+ tv.tv_sec = msec_remaining / 1000;
+ tv.tv_usec = (msec_remaining % 1000) * 1000;
ret = select(p[0]+1, &rdset, NULL, NULL, &tv);
+
switch (ret) {
case 0:
/* timer expired */
@@ -363,17 +390,19 @@ hash_output_from_command(entropy_source_t *src, char *hash)
error_abort = 1;
break;
}
- SHA1_Update(&sha, buf, bytes_read);
- total_bytes_read += bytes_read;
- RAND_add(&bytes_read, sizeof(&bytes_read), 0.0);
- cmd_eof = bytes_read ? 0 : 1;
+ if (bytes_read) {
+ SHA1_Update(&sha, buf, bytes_read);
+ total_bytes_read += bytes_read;
+ RAND_add(&bytes_read, sizeof(&bytes_read), 0.0);
+ } else
+ cmd_eof = 1;
break;
case -1:
default:
- error("Command '%s %s': select() failed: %s", src->path, src->args[1],
- strerror(errno));
+ debug("Command '%s': select() failed: %s", src->cmdstring,
+ strerror(errno));
error_abort = 1;
break;
} /* switch ret */
@@ -384,11 +413,12 @@ hash_output_from_command(entropy_source_t *src, char *hash)
SHA1_Final(hash, &sha);
close(p[0]);
+
+ debug("Time elapsed: %d msec", msec_elapsed);
if (waitpid(pid, &status, 0) == -1) {
- error("Couldn't wait for child '%s %s' completion: %s", src->path,
- src->args[1], strerror(errno));
- /* return(-1); */ /* FIXME: (ATL) this doesn't feel right */
+ debug("Couldn't wait for child '%s' completion: %s", src->cmdstring,
+ strerror(errno));
return(0.0);
}
@@ -398,7 +428,7 @@ hash_output_from_command(entropy_source_t *src, char *hash)
/* closing p[0] on timeout causes the entropy command to
* SIGPIPE. Take whatever output we got, and mark this command
* as slow */
- debug("Command %s %s timed out", src->path, src->args[1]);
+ debug("Command '%s' timed out", src->cmdstring);
src->sticky_badness *= 2;
src->badness = src->sticky_badness;
return(total_bytes_read);
@@ -615,6 +645,10 @@ prng_read_commands(char *cmdfilename)
continue;
}
+ /* save the command for debug messages */
+ entcmd[cur_cmd].cmdstring = (char*) xmalloc(strlen(cmd)+1);
+ strncpy(entcmd[cur_cmd].cmdstring, cmd, strlen(cmd)+1);
+
/* split the command args */
cp = strtok(cmd, WHITESPACE);
arg = 0; argv = NULL;
@@ -713,6 +747,9 @@ seed_rng(void)
debug("%i bytes from programs", (int)stir_from_programs());
debug("OpenSSL random status is now %i\n", RAND_status());
+ if (!RAND_status())
+ fatal("Couldn't initialise builtin random number generator -- exiting.");
+
if (!prng_seed_loaded)
{
prng_seed_loaded = 1;