#include "includes.h"
+#include <sys/types.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+#ifdef HAVE_SYS_UN_H
+# include <sys/un.h>
+#endif
+
+#include <signal.h>
+
#include <openssl/rand.h>
#include <openssl/sha.h>
#include <openssl/crypto.h>
# define SSH_PRNG_COMMAND_FILE SSHDIR "/ssh_prng_cmds"
#endif
-#ifdef HAVE___PROGNAME
extern char *__progname;
-#else
-char *__progname;
-#endif
-
-#ifndef offsetof
-# define offsetof(type, member) ((size_t) &((type *)0)->member)
-#endif
#define WHITESPACE " \t\n"
unsigned short tcp_port, char *socket_path)
{
int fd, addr_len, rval, errors;
- char msg[2];
+ u_char msg[2];
struct sockaddr_storage addr;
struct sockaddr_in *addr_in = (struct sockaddr_in *)&addr;
struct sockaddr_un *addr_un = (struct sockaddr_un *)&addr;
if (socket_path != NULL &&
strlen(socket_path) >= sizeof(addr_un->sun_path))
fatal("Random pool path is too long");
- if (len > 255)
- fatal("Too many bytes to read from PRNGD");
+ if (len <= 0 || len > 255)
+ fatal("Too many bytes (%d) to read from PRNGD", len);
memset(&addr, '\0', sizeof(addr));
goto done;
}
- if (atomicio(read, fd, buf, len) != len) {
+ if (atomicio(read, fd, buf, len) != (size_t)len) {
if (errno == EPIPE && errors < 10) {
close(fd);
errors++;
return rval;
}
+static int
+seed_from_prngd(unsigned char *buf, size_t bytes)
+{
+#ifdef PRNGD_PORT
+ debug("trying egd/prngd port %d", PRNGD_PORT);
+ if (get_random_bytes_prngd(buf, bytes, PRNGD_PORT, NULL) == 0)
+ return 0;
+#endif
+#ifdef PRNGD_SOCKET
+ debug("trying egd/prngd socket %s", PRNGD_SOCKET);
+ if (get_random_bytes_prngd(buf, bytes, 0, PRNGD_SOCKET) == 0)
+ return 0;
+#endif
+ return -1;
+}
+
double
stir_gettimeofday(double entropy_estimate)
{
debug3("Time elapsed: %d msec", msec_elapsed);
if (waitpid(pid, &status, 0) == -1) {
- error("Couldn't wait for child '%s' completion: %s",
- src->cmdstring, strerror(errno));
+ error("Couldn't wait for child '%s' completion: %s",
+ src->cmdstring, strerror(errno));
return 0.0;
}
void
prng_write_seedfile(void)
{
- int fd;
+ int fd, save_errno;
unsigned char seed[SEED_FILE_SIZE];
- char filename[MAXPATHLEN];
+ char filename[MAXPATHLEN], tmpseed[MAXPATHLEN];
struct passwd *pw;
+ mode_t old_umask;
pw = getpwuid(getuid());
if (pw == NULL)
snprintf(filename, sizeof(filename), "%.512s/%s", pw->pw_dir,
SSH_PRNG_SEED_FILE);
- debug("writing PRNG seed to file %.100s", filename);
+ strlcpy(tmpseed, filename, sizeof(tmpseed));
+ if (strlcat(tmpseed, ".XXXXXXXXXX", sizeof(tmpseed)) >=
+ sizeof(tmpseed))
+ fatal("PRNG seed filename too long");
if (RAND_bytes(seed, sizeof(seed)) <= 0)
fatal("PRNG seed extraction failed");
/* Don't care if the seed doesn't exist */
prng_check_seedfile(filename);
- if ((fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0600)) == -1) {
- debug("WARNING: couldn't access PRNG seedfile %.100s "
- "(%.100s)", filename, strerror(errno));
+ old_umask = umask(0177);
+
+ if ((fd = mkstemp(tmpseed)) == -1) {
+ debug("WARNING: couldn't make temporary PRNG seedfile %.100s "
+ "(%.100s)", tmpseed, strerror(errno));
} else {
- if (atomicio(vwrite, fd, &seed, sizeof(seed)) < sizeof(seed))
+ debug("writing PRNG seed to file %.100s", tmpseed);
+ if (atomicio(vwrite, fd, &seed, sizeof(seed)) < sizeof(seed)) {
+ save_errno = errno;
+ close(fd);
+ unlink(tmpseed);
fatal("problem writing PRNG seedfile %.100s "
- "(%.100s)", filename, strerror(errno));
+ "(%.100s)", filename, strerror(save_errno));
+ }
close(fd);
+ debug("moving temporary PRNG seed to file %.100s", filename);
+ if (rename(tmpseed, filename) == -1) {
+ save_errno = errno;
+ unlink(tmpseed);
+ fatal("problem renaming PRNG seedfile from %.100s "
+ "to %.100s (%.100s)", tmpseed, filename,
+ strerror(save_errno));
+ }
}
+ umask(old_umask);
}
void
fprintf(stderr, "Usage: %s [options]\n", __progname);
fprintf(stderr, " -v Verbose; display verbose debugging messages.\n");
fprintf(stderr, " Multiple -v increases verbosity.\n");
- fprintf(stderr, " -x Force output in hexidecimal (for debugging)\n");
+ fprintf(stderr, " -x Force output in hexadecimal (for debugging)\n");
fprintf(stderr, " -X Force output in binary\n");
fprintf(stderr, " -b bytes Number of bytes to output (default %d)\n",
OUTPUT_SEED_SIZE);
/* Don't write binary data to a tty, unless we are forced to */
if (isatty(STDOUT_FILENO))
output_hex = 1;
-
+
while ((ch = getopt(argc, argv, "vxXhb:")) != -1) {
switch (ch) {
case 'v':
}
log_init(argv[0], ll, SYSLOG_FACILITY_USER, 1);
-
+
#ifdef USE_SEED_FILES
prng_read_seedfile();
#endif
/*
* Seed the RNG from wherever we can
*/
-
+
/* Take whatever is on the stack, but don't credit it */
RAND_add(buf, bytes, 0);
debug("Seeded RNG with %i bytes from system calls",
(int)stir_from_system());
-#ifdef PRNGD_PORT
- if (get_random_bytes_prngd(buf, bytes, PRNGD_PORT, NULL) == -1)
- fatal("Entropy collection failed");
- RAND_add(buf, bytes, bytes);
-#elif defined(PRNGD_SOCKET)
- if (get_random_bytes_prngd(buf, bytes, 0, PRNGD_SOCKET) == -1)
- fatal("Entropy collection failed");
- RAND_add(buf, bytes, bytes);
-#else
- /* Read in collection commands */
- if (prng_read_commands(SSH_PRNG_COMMAND_FILE) == -1)
- fatal("PRNG initialisation failed -- exiting.");
- debug("Seeded RNG with %i bytes from programs",
- (int)stir_from_programs());
-#endif
+ /* try prngd, fall back to commands if prngd fails or not configured */
+ if (seed_from_prngd(buf, bytes) == 0) {
+ RAND_add(buf, bytes, bytes);
+ } else {
+ /* Read in collection commands */
+ if (prng_read_commands(SSH_PRNG_COMMAND_FILE) == -1)
+ fatal("PRNG initialisation failed -- exiting.");
+ debug("Seeded RNG with %i bytes from programs",
+ (int)stir_from_programs());
+ }
#ifdef USE_SEED_FILES
prng_write_seedfile();
printf("\n");
} else
ret = atomicio(vwrite, STDOUT_FILENO, buf, bytes);
-
+
memset(buf, '\0', bytes);
xfree(buf);
-
+
return ret == bytes ? 0 : 1;
}
+
+/*
+ * We may attempt to re-seed during mkstemp if we are using the one in the
+ * compat library (via mkstemp -> _gettemp -> arc4random -> seed_rng) so we
+ * need our own seed_rng(). We must also check that we have enough entropy.
+ */
+void
+seed_rng(void)
+{
+ if (!RAND_status())
+ fatal("Not enough entropy in RNG");
+}
andersk / openssh.git / blobdiff