Use hash from /etc/login.defs as default if no

other one is specified as argument.

* modules/pam_unix/support.c: Add search_key, call from __set_ctrl
* modules/pam_unix/support.h: Add define for /etc/login.defs
* modules/pam_unix/pam_unix.8.xml: Document new behavior.
* modules/pam_umask/pam_umask.c: Add missing NULL pointer check

1 files changed, 105 insertions, 1 deletions

diff --git a/modules/pam_unix/support.c b/modules/pam_unix/support.c
index ab04535f..f36786e4 100644
--- a/modules/pam_unix/support.c
+++ b/modules/pam_unix/support.c
@@ -37,6 +37,80 @@
 #define SELINUX_ENABLED 0
 #endif
 
+static char *
+search_key (const char *key, const char *filename)
+{
+  FILE *fp;
+  char *buf = NULL;
+  size_t buflen = 0;
+  char *retval = NULL;
+
+  fp = fopen (filename, "r");
+  if (NULL == fp)
+    return NULL;
+
+  while (!feof (fp))
+    {
+      char *tmp, *cp;
+#if defined(HAVE_GETLINE)
+      ssize_t n = getline (&buf, &buflen, fp);
+#elif defined (HAVE_GETDELIM)
+      ssize_t n = getdelim (&buf, &buflen, '\n', fp);
+#else
+      ssize_t n;
+
+      if (buf == NULL)
+        {
+          buflen = BUF_SIZE;
+          buf = malloc (buflen);
+	  if (buf == NULL) {
+	    fclose (fp);
+	    return NULL;
+	  }
+        }
+      buf[0] = '\0';
+      if (fgets (buf, buflen - 1, fp) == NULL)
+        break;
+      else if (buf != NULL)
+        n = strlen (buf);
+      else
+        n = 0;
+#endif /* HAVE_GETLINE / HAVE_GETDELIM */
+      cp = buf;
+
+      if (n < 1)
+        break;
+
+      tmp = strchr (cp, '#');  /* remove comments */
+      if (tmp)
+        *tmp = '\0';
+      while (isspace ((int)*cp))    /* remove spaces and tabs */
+        ++cp;
+      if (*cp == '\0')        /* ignore empty lines */
+        continue;
+
+      if (cp[strlen (cp) - 1] == '\n')
+        cp[strlen (cp) - 1] = '\0';
+
+      tmp = strsep (&cp, " \t=");
+      if (cp != NULL)
+        while (isspace ((int)*cp) || *cp == '=')
+          ++cp;
+
+      if (strcasecmp (tmp, key) == 0)
+        {
+          retval = strdup (cp);
+          break;
+        }
+    }
+  fclose (fp);
+
+  free (buf);
+
+  return retval;
+}
+
+
 /* this is a front-end for module-application conversations */
 
 int _make_remark(pam_handle_t * pamh, unsigned int ctrl,
@@ -58,6 +132,8 @@ int _set_ctrl(pam_handle_t *pamh, int flags, int *remember, int *rounds,
 	      int *pass_min_len, int argc, const char **argv)
 {
 	unsigned int ctrl;
+	char *val;
+	int j;
 
 	D(("called."));
 
@@ -81,10 +157,38 @@ int _set_ctrl(pam_handle_t *pamh, int flags, int *remember, int *rounds,
 		D(("SILENT"));
 		set(UNIX__QUIET, ctrl);
 	}
+
+	/* preset encryption method with value from /etc/login.defs */
+	val = search_key ("ENCRYPT_METHOD", LOGIN_DEFS);
+	if (val) {
+	  for (j = 0; j < UNIX_CTRLS_; ++j) {
+	    if (unix_args[j].token && unix_args[j].is_hash_algo
+		&& !strncasecmp(val, unix_args[j].token, strlen(unix_args[j].token))) {
+	      break;
+	    }
+	  }
+	  if (j >= UNIX_CTRLS_) {
+	    pam_syslog(pamh, LOG_WARNING, "unrecognized ENCRYPT_METHOD value [%s]", val);
+	  } else {
+	    ctrl &= unix_args[j].mask;	/* for turning things off */
+	    ctrl |= unix_args[j].flag;	/* for turning things on  */
+	  }
+	  free (val);
+
+	  /* read number of rounds for crypt algo */
+	  if (on(UNIX_SHA256_PASS, ctrl) || on(UNIX_SHA512_PASS, ctrl)) {
+	    val=search_key ("SHA_CRYPT_MAX_ROUNDS", LOGIN_DEFS);
+
+	    if (val) {
+	      *rounds = strtol(val, NULL, 10);
+	      free (val);
+	    }
+	  }
+	}
+
 	/* now parse the arguments to this module */
 
 	for (; argc-- > 0; ++argv) {
-		int j;
 
 		D(("pam_unix arg: %s", *argv));