#include <openssl/rand.h>
#include <openssl/sha.h>
+/* SunOS 4.4.4 needs this */
+#ifdef HAVE_FLOATINGPOINT_H
+# include <floatingpoint.h>
+#endif /* HAVE_FLOATINGPOINT_H */
+
RCSID("$Id$");
-#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"
+
+#ifndef RUSAGE_SELF
+# define RUSAGE_SELF 0
+#endif
+#ifndef RUSAGE_CHILDREN
+# define RUSAGE_CHILDREN 0
+#endif
+
+#if defined(EGD_SOCKET) || defined(RANDOM_POOL)
+
+#ifdef EGD_SOCKET
/* Collect entropy from EGD */
-void get_random_bytes(unsigned char *buf, int len)
+int get_random_bytes(unsigned char *buf, int len)
{
- static int egd_socket = -1;
- int c;
- char egd_message[2] = { 0x02, 0x00 };
+ int fd;
+ char msg[2];
struct sockaddr_un addr;
int addr_len;
- memset(&addr, '\0', sizeof(addr));
- addr.sun_family = AF_UNIX;
-
- /* FIXME: compile time check? */
+ /* Sanity checks */
if (sizeof(EGD_SOCKET) > sizeof(addr.sun_path))
fatal("Random pool path is too long");
-
- strcpy(addr.sun_path, EGD_SOCKET);
-
- addr_len = offsetof(struct sockaddr_un, sun_path) + sizeof(EGD_SOCKET);
-
- if (egd_socket == -1) {
- egd_socket = socket(AF_UNIX, SOCK_STREAM, 0);
- if (egd_socket == -1)
- fatal("Couldn't create AF_UNIX socket: %s", strerror(errno));
- if (connect(egd_socket, (struct sockaddr*)&addr, addr_len) == -1)
- fatal("Couldn't connect to EGD socket \"%s\": %s", addr.sun_path, strerror(errno));
- }
-
if (len > 255)
fatal("Too many bytes to read from EGD");
+
+ memset(&addr, '\0', sizeof(addr));
+ addr.sun_family = AF_UNIX;
+ strlcpy(addr.sun_path, EGD_SOCKET, sizeof(addr.sun_path));
+ addr_len = offsetof(struct sockaddr_un, sun_path) + sizeof(EGD_SOCKET);
+ fd = socket(AF_UNIX, SOCK_STREAM, 0);
+ if (fd == -1) {
+ error("Couldn't create AF_UNIX socket: %s", strerror(errno));
+ return(0);
+ }
+
+ if (connect(fd, (struct sockaddr*)&addr, addr_len) == -1) {
+ error("Couldn't connect to EGD socket \"%s\": %s",
+ addr.sun_path, strerror(errno));
+ close(fd);
+ return(0);
+ }
+
/* Send blocking read request to EGD */
- egd_message[1] = len;
+ msg[0] = 0x02;
+ msg[1] = len;
- c = atomicio(write, egd_socket, egd_message, sizeof(egd_message));
- if (c == -1)
- fatal("Couldn't write to EGD socket \"%s\": %s", EGD_SOCKET, strerror(errno));
+ if (atomicio(write, fd, msg, sizeof(msg)) != sizeof(msg)) {
+ error("Couldn't write to EGD socket \"%s\": %s",
+ EGD_SOCKET, strerror(errno));
+ close(fd);
+ return(0);
+ }
- c = atomicio(read, egd_socket, buf, len);
- if (c <= 0)
- fatal("Couldn't read from EGD socket \"%s\": %s", EGD_SOCKET, strerror(errno));
+ if (atomicio(read, fd, buf, len) != len) {
+ error("Couldn't read from EGD socket \"%s\": %s",
+ EGD_SOCKET, strerror(errno));
+ close(fd);
+ return(0);
+ }
- close(EGD_SOCKET);
+ close(fd);
+
+ return(1);
}
#else /* !EGD_SOCKET */
#ifdef RANDOM_POOL
/* Collect entropy from /dev/urandom or pipe */
-void get_random_bytes(unsigned char *buf, int len)
+int get_random_bytes(unsigned char *buf, int len)
{
- static int random_pool = -1;
- int c;
+ int random_pool;
+ random_pool = open(RANDOM_POOL, O_RDONLY);
if (random_pool == -1) {
- random_pool = open(RANDOM_POOL, O_RDONLY);
- if (random_pool == -1)
- fatal("Couldn't open random pool \"%s\": %s", RANDOM_POOL, strerror(errno));
+ error("Couldn't open random pool \"%s\": %s",
+ RANDOM_POOL, strerror(errno));
+ return(0);
+ }
+
+ if (atomicio(read, random_pool, buf, len) != len) {
+ error("Couldn't read from random pool \"%s\": %s",
+ RANDOM_POOL, strerror(errno));
+ close(random_pool);
+ return(0);
}
- c = atomicio(read, random_pool, buf, len);
- if (c <= 0)
- fatal("Couldn't read from random pool \"%s\": %s", RANDOM_POOL, strerror(errno));
+ close(random_pool);
+
+ return(1);
}
#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");
+
+ if (!get_random_bytes(buf, sizeof(buf))) {
+ if (!RAND_status())
+ fatal("Entropy collection failed and entropy exhausted");
+ } else {
+ RAND_add(buf, sizeof(buf), sizeof(buf));
+ }
+
+ memset(buf, '\0', sizeof(buf));
+}
+
+/* No-op */
+void init_rng(void) {}
+
+#else /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */
+
/*
* FIXME: proper entropy estimations. All current values are guesses
* FIXME: (ATL) do estimates at compile time?
/* static int entropy_timeout_default = ENTROPY_TIMEOUT_MSEC; */
static int entropy_timeout_current = ENTROPY_TIMEOUT_MSEC;
-static int prng_seed_loaded = 0;
static int prng_seed_saved = 0;
-static int prng_commands_loaded = 0;
+static int prng_initialised = 0;
+uid_t original_uid;
typedef struct
{
/* 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)
total_entropy_estimate = 0;
i = getpid();
- RAND_add(&i, sizeof(i), 0.1);
+ RAND_add(&i, sizeof(i), 0.5);
total_entropy_estimate += 0.1;
i = getppid();
- RAND_add(&i, sizeof(i), 0.1);
+ RAND_add(&i, sizeof(i), 0.5);
total_entropy_estimate += 0.1;
i = getuid();
RAND_add(&i, sizeof(i), 0.0);
total_entropy_estimate += stir_gettimeofday(1.0);
- total_entropy_estimate += stir_clock(0.2);
+ total_entropy_estimate += stir_clock(0.5);
total_entropy_estimate += stir_rusage(RUSAGE_SELF, 2.0);
return(total_entropy_estimate);
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) {
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
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
struct rusage ru;
if (getrusage(who, &ru) == -1)
- fatal("Couldn't getrusage: %s", strerror(errno));
+ return(0);
- RAND_add(&ru, sizeof(ru), 0.1);
+ RAND_add(&ru, sizeof(ru), entropy_estimate);
return(entropy_estimate);
#else /* _HAVE_GETRUSAGE */
close(p[1]);
close(devnull);
+ setuid(original_uid);
execv(src->path, (char**)(src->args));
debug("(child) Couldn't exec '%s': %s", src->cmdstring,
strerror(errno));
- src->badness = src->sticky_badness = 128;
_exit(-1);
default: /* Parent */
break;
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;
ret = select(p[0]+1, &rdset, NULL, NULL, &tv);
+ RAND_add(&tv, sizeof(tv), 0.0);
+
switch (ret) {
case 0:
/* timer expired */
error_abort = 1;
break;
-
case 1:
/* command input */
bytes_read = read(p[0], buf, sizeof(buf));
+ RAND_add(&bytes_read, sizeof(&bytes_read), 0.0);
if (bytes_read == -1) {
error_abort = 1;
break;
- }
- if (bytes_read) {
+ } else if (bytes_read) {
SHA1_Update(&sha, buf, bytes_read);
total_bytes_read += bytes_read;
- RAND_add(&bytes_read, sizeof(&bytes_read), 0.0);
- } else
+ } else {
cmd_eof = 1;
-
+ }
break;
-
case -1:
default:
+ /* error */
debug("Command '%s': select() failed: %s", src->cmdstring,
strerror(errno));
error_abort = 1;
break;
- } /* switch ret */
-
- RAND_add(&tv, sizeof(&tv), 0.0);
- } /* while !error_abort && !cmd_eof */
+ }
+ }
SHA1_Final(hash, &sha);
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,
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
fatal("PRNG seedfile %.100s is not a regular file", filename);
/* mode 0600, owned by root or the current user? */
- if (((st.st_mode & 0177) != 0) || !(st.st_uid == getuid()))
+ if (((st.st_mode & 0177) != 0) || !(st.st_uid == original_uid))
fatal("PRNG seedfile %.100s must be mode 0600, owned by uid %d",
filename, getuid());
if (prng_seed_saved)
return;
+ setuid(original_uid);
+
prng_seed_saved = 1;
- pw = getpwuid(getuid());
+ pw = getpwuid(original_uid);
if (pw == NULL)
fatal("Couldn't get password entry for current user (%i): %s",
- getuid(), strerror(errno));
+ original_uid, strerror(errno));
/* Try to ensure that the parent directory is there */
snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir,
char filename[1024];
struct passwd *pw;
- pw = getpwuid(getuid());
+ pw = getpwuid(original_uid);
if (pw == NULL)
fatal("Couldn't get password entry for current user (%i): %s",
- getuid(), strerror(errno));
+ original_uid, strerror(errno));
snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir,
SSH_PRNG_SEED_FILE);
/*
* 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) {
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 */
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 */
+ /* First non-whitespace char should be double quote delimiting */
+ /* commandline */
+ if (*cp != '"') {
+ error("bad entropy command, %.100s line %d", cmdfilename,
+ linenum);
+ continue;
+ }
- /* end of line */
- if ((cp = strtok(NULL, WHITESPACE)) != NULL) {
- error("garbage at end of line %d in %.100s -- ignored",
- linenum, cmdfilename);
- 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;
+ }
- /* 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;
+ /* did configure mark this as dead? */
+ if (strncmp("undef", cp, 5) == 0)
+ continue;
- default:
- error("bad entropy command, %.100s line %d", cmdfilename,
- linenum);
+ 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));
- debug("loaded %d entropy commands from %.100s", cur_cmd, cmdfilename);
+ debug("Loaded %d entropy commands from %.100s", cur_cmd, cmdfilename);
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
*/
void
seed_rng(void)
{
- if (!prng_commands_loaded) {
- if (!prng_read_commands(SSH_PRNG_COMMAND_FILE))
- fatal("PRNG initialisation failed -- exiting.");
- prng_commands_loaded = 1;
- }
+ void *old_sigchld_handler;
+
+ if (!prng_initialised)
+ fatal("RNG not initialised");
+
+ /* Make sure some other sigchld handler doesn't reap our entropy */
+ /* commands */
+ old_sigchld_handler = signal(SIGCHLD, SIG_DFL);
- debug("Seeding random number generator.");
- debug("OpenSSL random status is now %i\n", RAND_status());
- debug("%i bytes from system calls", (int)stir_from_system());
- debug("%i bytes from programs", (int)stir_from_programs());
- debug("OpenSSL random status is now %i\n", RAND_status());
+ debug("Seeded RNG with %i bytes from programs", (int)stir_from_programs());
+ debug("Seeded RNG with %i bytes from system calls", (int)stir_from_system());
+
+ if (!RAND_status())
+ fatal("Not enough entropy in RNG");
+
+ signal(SIGCHLD, old_sigchld_handler);
if (!RAND_status())
fatal("Couldn't initialise builtin random number generator -- exiting.");
+}
- if (!prng_seed_loaded)
- {
- prng_seed_loaded = 1;
- prng_seed_saved = 0;
- prng_read_seedfile();
- fatal_add_cleanup(prng_seed_cleanup, NULL);
- atexit(prng_write_seedfile);
- }
+void init_rng(void)
+{
+ original_uid = getuid();
+
+ /* Read in collection commands */
+ if (!prng_read_commands(SSH_PRNG_COMMAND_FILE))
+ fatal("PRNG initialisation failed -- exiting.");
+
+ /* Set ourselves up to save a seed upon exit */
+ prng_seed_saved = 0;
+ prng_read_seedfile();
+ fatal_add_cleanup(prng_seed_cleanup, NULL);
+ atexit(prng_write_seedfile);
+
+ prng_initialised = 1;
}
+
#endif /* defined(EGD_SOCKET) || defined(RANDOM_POOL) */
andersk / openssh.git / blobdiff