- 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

1 files changed, 58 insertions, 21 deletions

diff --git a/entropy.c b/entropy.c
index 2a1db4202..79ef93ac6 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;