- (djm) Cleanup of entropy.c. Reorganised code, removed second pass through
list of commands (by default). Removed verbose debugging (by default).
- (djm) Increased command entropy estimates and default entropy collection
timeout
diff --git a/entropy.c b/entropy.c
index ffadd32..cbb36fd 100644
--- a/entropy.c
+++ b/entropy.c
@@ -35,12 +35,29 @@
#include <openssl/rand.h>
#include <openssl/sha.h>
-RCSID("$Id: entropy.c,v 1.12 2000/05/31 01:24:34 damien Exp $");
+RCSID("$Id: entropy.c,v 1.13 2000/06/07 12:20:23 djm Exp $");
-#ifdef EGD_SOCKET
#ifndef offsetof
# define offsetof(type, member) ((size_t) &((type *)0)->member)
#endif
+
+/* Print lots of detail */
+/* #define DEBUG_ENTROPY */
+
+/* Number of times to pass through command list gathering entropy */
+#define NUM_ENTROPY_RUNS 1
+
+/* Scale entropy estimates back by this amount on subsequent runs */
+#define SCALE_PER_RUN 10.0
+
+/* Minimum number of commands to be considered valid */
+#define MIN_ENTROPY_SOURCES 16
+
+#define WHITESPACE " \t\n"
+
+#if defined(EGD_SOCKET) || defined(RANDOM_POOL)
+
+#ifdef EGD_SOCKET
/* Collect entropy from EGD */
void get_random_bytes(unsigned char *buf, int len)
{
@@ -57,7 +74,7 @@
if (sizeof(EGD_SOCKET) > sizeof(addr.sun_path))
fatal("Random pool path is too long");
- strcpy(addr.sun_path, EGD_SOCKET);
+ strlcpy(addr.sun_path, EGD_SOCKET, sizeof(addr.sun_path));
addr_len = offsetof(struct sockaddr_un, sun_path) + sizeof(EGD_SOCKET);
@@ -104,7 +121,23 @@
#endif /* RANDOM_POOL */
#endif /* EGD_SOCKET */
-#if !defined(EGD_SOCKET) && !defined(RANDOM_POOL)
+/*
+ * Seed OpenSSL's random number pool from Kernel random number generator
+ * or EGD
+ */
+void
+seed_rng(void)
+{
+ char buf[32];
+
+ debug("Seeding random number generator");
+ get_random_bytes(buf, sizeof(buf));
+ RAND_add(buf, sizeof(buf), sizeof(buf));
+ memset(buf, '\0', sizeof(buf));
+}
+
+#else /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */
+
/*
* FIXME: proper entropy estimations. All current values are guesses
* FIXME: (ATL) do estimates at compile time?
@@ -144,8 +177,6 @@
/* this is initialised from a file, by prng_read_commands() */
entropy_source_t *entropy_sources = NULL;
-#define MIN_ENTROPY_SOURCES 16
-
double
stir_from_system(void)
@@ -184,11 +215,8 @@
double total_entropy_estimate;
char hash[SHA_DIGEST_LENGTH];
- /*
- * Run through list of programs twice to catch differences
- */
total_entropy_estimate = 0;
- for(i = 0; i < 2; i++) {
+ for(i = 0; i < NUM_ENTROPY_RUNS; i++) {
c = 0;
while (entropy_sources[c].path != NULL) {
@@ -203,14 +231,13 @@
if (entropy_estimate > SHA_DIGEST_LENGTH)
entropy_estimate = SHA_DIGEST_LENGTH;
- /* * Scale back estimates for subsequent passes through list */
- entropy_estimate /= 10.0 * (i + 1.0);
+ /* Scale back estimates for subsequent passes through list */
+ entropy_estimate /= SCALE_PER_RUN * (i + 1.0);
/* Stir it in */
RAND_add(hash, sizeof(hash), entropy_estimate);
-/* FIXME: turn this off later */
-#if 1
+#ifdef DEBUG_ENTROPY
debug("Got %0.2f bytes of entropy from '%s'", entropy_estimate,
entropy_sources[c].cmdstring);
#endif
@@ -223,8 +250,7 @@
total_entropy_estimate += stir_rusage(RUSAGE_SELF, 0.1);
total_entropy_estimate += stir_rusage(RUSAGE_CHILDREN, 0.1);
} else {
-/* FIXME: turn this off later */
-#if 1
+#ifdef DEBUG_ENTROPY
debug("Command '%s' disabled (badness %d)",
entropy_sources[c].cmdstring, entropy_sources[c].badness);
#endif
@@ -360,8 +386,7 @@
int msec_remaining;
(void) gettimeofday(&tv_current, 0);
- msec_elapsed = _get_timeval_msec_difference(
- &tv_start, &tv_current);
+ msec_elapsed = _get_timeval_msec_difference(&tv_start, &tv_current);
if (msec_elapsed >= entropy_timeout_current) {
error_abort=1;
continue;
@@ -412,7 +437,9 @@
close(p[0]);
+#ifdef DEBUG_ENTROPY
debug("Time elapsed: %d msec", msec_elapsed);
+#endif
if (waitpid(pid, &status, 0) == -1) {
debug("Couldn't wait for child '%s' completion: %s", src->cmdstring,
@@ -436,12 +463,14 @@
if (WEXITSTATUS(status)==0) {
return(total_bytes_read);
} else {
- debug("Exit status was %d", WEXITSTATUS(status));
+ debug("Command '%s' exit status was %d", src->cmdstring,
+ WEXITSTATUS(status));
src->badness = src->sticky_badness = 128;
return (0.0);
}
} else if (WIFSIGNALED(status)) {
- debug("Returned on uncaught signal %d !", status);
+ debug("Command '%s' returned on uncaught signal %d !", src->cmdstring,
+ status);
src->badness = src->sticky_badness = 128;
return(0.0);
} else
@@ -571,20 +600,19 @@
/*
* entropy command initialisation functions
*/
-#define WHITESPACE " \t\n"
-
int
prng_read_commands(char *cmdfilename)
{
FILE *f;
- char line[1024];
- char cmd[1024], path[256];
- double est;
char *cp;
+ char line[1024];
+ char cmd[1024];
+ char path[256];
int linenum;
- entropy_source_t *entcmd;
int num_cmds = 64;
int cur_cmd = 0;
+ double est;
+ entropy_source_t *entcmd;
f = fopen(cmdfilename, "r");
if (!f) {
@@ -592,12 +620,15 @@
cmdfilename, strerror(errno));
}
- linenum = 0;
-
entcmd = (entropy_source_t *)xmalloc(num_cmds * sizeof(entropy_source_t));
memset(entcmd, '\0', num_cmds * sizeof(entropy_source_t));
+ /* Read in file */
+ linenum = 0;
while (fgets(line, sizeof(line), f)) {
+ int arg;
+ char *argv;
+
linenum++;
/* skip leading whitespace, test for blank line or comment */
@@ -605,88 +636,90 @@
if ((*cp == 0) || (*cp == '#'))
continue; /* done with this line */
- switch (*cp) {
- int arg;
- char *argv;
-
- case '"':
- /* first token, command args (incl. argv[0]) in double quotes */
- cp = strtok(cp, "\"");
- if (cp==NULL) {
- error("missing or bad command string, %.100s line %d -- ignored",
- cmdfilename, linenum);
- continue;
- }
- strncpy(cmd, cp, sizeof(cmd));
- /* second token, full command path */
- if ((cp = strtok(NULL, WHITESPACE)) == NULL) {
- error("missing command path, %.100s line %d -- ignored",
- cmdfilename, linenum);
- continue;
- }
- if (strncmp("undef", cp, 5)==0) /* did configure mark this as dead? */
- continue;
-
- strncpy(path, cp, sizeof(path));
- /* third token, entropy rate estimate for this command */
- if ( (cp = strtok(NULL, WHITESPACE)) == NULL) {
- error("missing entropy estimate, %.100s line %d -- ignored",
- cmdfilename, linenum);
- continue;
- }
- est = strtod(cp, &argv);/* FIXME: (ATL) no error checking here */
-
- /* end of line */
- if ((cp = strtok(NULL, WHITESPACE)) != NULL) {
- error("garbage at end of line %d in %.100s -- ignored",
- linenum, 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;
- do {
- char *s = (char*)xmalloc(strlen(cp)+1);
- strncpy(s, cp, strlen(cp)+1);
- entcmd[cur_cmd].args[arg] = s;
- arg++;
- } while ((arg < 5) && (cp = strtok(NULL, WHITESPACE)));
- if (strtok(NULL, WHITESPACE))
- error("ignored extra command elements (max 5), %.100s line %d",
- cmdfilename, linenum);
-
- /* copy the command path and rate estimate */
- entcmd[cur_cmd].path = (char *)xmalloc(strlen(path)+1);
- strncpy(entcmd[cur_cmd].path, path, strlen(path)+1);
- entcmd[cur_cmd].rate = est;
- /* initialise other values */
- entcmd[cur_cmd].sticky_badness = 1;
-
- cur_cmd++;
-
- /* If we've filled the array, reallocate it twice the size */
- /* Do this now because even if this we're on the last command,
- we need another slot to mark the last entry */
- if (cur_cmd == num_cmds) {
- num_cmds *= 2;
- entcmd = xrealloc(entcmd, num_cmds * sizeof(entropy_source_t));
- }
- break;
-
- default:
+ /* First non-whitespace char should be double quote delimiting */
+ /* commandline */
+ if (*cp != '"') {
error("bad entropy command, %.100s line %d", cmdfilename,
linenum);
continue;
+ }
+
+ /* first token, command args (incl. argv[0]) in double quotes */
+ cp = strtok(cp, "\"");
+ if (cp == NULL) {
+ error("missing or bad command string, %.100s line %d -- ignored",
+ cmdfilename, linenum);
+ continue;
+ }
+ strlcpy(cmd, cp, sizeof(cmd));
+
+ /* second token, full command path */
+ if ((cp = strtok(NULL, WHITESPACE)) == NULL) {
+ error("missing command path, %.100s line %d -- ignored",
+ cmdfilename, linenum);
+ continue;
+ }
+
+ /* did configure mark this as dead? */
+ if (strncmp("undef", cp, 5) == 0)
+ continue;
+
+ strlcpy(path, cp, sizeof(path));
+
+ /* third token, entropy rate estimate for this command */
+ if ((cp = strtok(NULL, WHITESPACE)) == NULL) {
+ error("missing entropy estimate, %.100s line %d -- ignored",
+ cmdfilename, linenum);
+ continue;
+ }
+ est = strtod(cp, &argv);
+
+ /* end of line */
+ if ((cp = strtok(NULL, WHITESPACE)) != NULL) {
+ error("garbage at end of line %d in %.100s -- ignored", linenum,
+ cmdfilename);
+ continue;
+ }
+
+ /* save the command for debug messages */
+ entcmd[cur_cmd].cmdstring = xstrdup(cmd);
+
+ /* split the command args */
+ cp = strtok(cmd, WHITESPACE);
+ arg = 0;
+ argv = NULL;
+ do {
+ char *s = (char*)xmalloc(strlen(cp) + 1);
+ strncpy(s, cp, strlen(cp) + 1);
+ entcmd[cur_cmd].args[arg] = s;
+ arg++;
+ } while ((arg < 5) && (cp = strtok(NULL, WHITESPACE)));
+
+ if (strtok(NULL, WHITESPACE))
+ error("ignored extra command elements (max 5), %.100s line %d",
+ cmdfilename, linenum);
+
+ /* Copy the command path and rate estimate */
+ entcmd[cur_cmd].path = xstrdup(path);
+ entcmd[cur_cmd].rate = est;
+
+ /* Initialise other values */
+ entcmd[cur_cmd].sticky_badness = 1;
+
+ cur_cmd++;
+
+ /* If we've filled the array, reallocate it twice the size */
+ /* Do this now because even if this we're on the last command,
+ we need another slot to mark the last entry */
+ if (cur_cmd == num_cmds) {
+ num_cmds *= 2;
+ entcmd = xrealloc(entcmd, num_cmds * sizeof(entropy_source_t));
}
}
/* zero the last entry */
memset(&entcmd[cur_cmd], '\0', sizeof(entropy_source_t));
+
/* trim to size */
entropy_sources = xrealloc(entcmd, (cur_cmd+1) * sizeof(entropy_source_t));
@@ -695,28 +728,6 @@
return (cur_cmd >= MIN_ENTROPY_SOURCES);
}
-
-#endif /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */
-
-#if defined(EGD_SOCKET) || defined(RANDOM_POOL)
-
-/*
- * Seed OpenSSL's random number pool from Kernel random number generator
- * or EGD
- */
-void
-seed_rng(void)
-{
- char buf[32];
-
- debug("Seeding random number generator");
- get_random_bytes(buf, sizeof(buf));
- RAND_add(buf, sizeof(buf), sizeof(buf));
- memset(buf, '\0', sizeof(buf));
-}
-
-#else /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */
-
/*
* Write a keyfile at exit
*/