remove acconfig.h

[openssh.git] / ssh-rand-helper.c

diff --git a/ssh-rand-helper.c b/ssh-rand-helper.c
index 0f70f6b21e27da89b464ece6287da3a2293bec48..d8517b1a32a7a0aae6d8840123392db2760ac7de 100644 (file)
--- a/ssh-rand-helper.c
+++ b/ssh-rand-helper.c
@@ -123,7 +123,7 @@ get_random_bytes_prngd(unsigned char *buf, int len,
     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;
@@ -135,8 +135,8 @@ get_random_bytes_prngd(unsigned char *buf, int len,
        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));
 
@@ -190,7 +190,7 @@ reopen:
                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++;
@@ -398,8 +398,8 @@ hash_command_output(entropy_cmd_t *src, unsigned char *hash)
        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;
        }
 
@@ -550,10 +550,11 @@ prng_check_seedfile(char *filename)
 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)
@@ -568,7 +569,10 @@ prng_write_seedfile(void)
        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");
@@ -576,15 +580,31 @@ prng_write_seedfile(void)
        /* 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
@@ -868,3 +888,15 @@ main(int argc, char **argv)
 
        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");
+}