yp-tools/yp-tools-2.7-md5.patch

--- yp-tools-2.8/src/yppasswd.c.orig	2002-12-05 08:49:20.000000000 -0500
+++ yp-tools-2.8/src/yppasswd.c	2003-04-23 14:58:13.000000000 -0400
@@ -49,6 +49,8 @@
 #include <locale.h>
 #include <libintl.h>
 #include <sys/param.h>
+#include <sys/types.h>
+#include <fcntl.h>
 #include <sys/stat.h>
 #include <rpcsvc/yp_prot.h>
 #include <rpcsvc/ypclnt.h>
@@ -436,11 +438,44 @@ verifypassword (struct passwd *pwd, char
 
 #endif
 
+#define bin_to_ascii(c) ((c)>=38?((c)-38+'a'):(c)>=12?((c)-12+'A'):(c)+'.')
+
+static void
+create_random_salt (char *salt, int num_chars)
+{
+  int fd;
+  unsigned char c;
+  int i;
+  int res;
+  
+  fd = open("/dev/urandom", O_RDONLY);
+
+  for (i = 0; i < num_chars; i++)
+    {
+      res = 0;
+      
+      if (fd != 0)
+	res = read (fd, &c, 1);
+
+      if (res != 1)
+	c = random();
+      
+      salt[i] = bin_to_ascii(c & 0x3f);
+    }
+  
+  salt[num_chars] = 0;
+
+  if (fd != 0)
+    close (fd);
+}
+
+
 int
 main (int argc, char **argv)
 {
   char *s, *progname, *domainname = NULL, *user = NULL, *master = NULL;
   int f_flag = 0, l_flag = 0, p_flag = 0, error, status;
+  int has_md5_passwd = 0;
   struct yppasswd yppwd;
   struct passwd *pwd;
   CLIENT *clnt;
@@ -451,6 +486,8 @@ main (int argc, char **argv)
   bindtextdomain (PACKAGE, LOCALEDIR);
   textdomain (PACKAGE);
 
+  srandom (time (NULL));
+
   if ((s = strrchr (argv[0], '/')) != NULL)
     progname = s + 1;
   else
@@ -642,6 +679,9 @@ main (int argc, char **argv)
       cp = stpcpy (hashpass, "##");
       strcpy (cp, pwd->pw_name);
 
+      if (strncmp(pwd->pw_passwd, "$1$", 3) == 0)
+	has_md5_passwd = 1;
+
       /* We can't check the password with shadow passwords enabled. We
        * leave the checking to yppasswdd */
       if (uid != 0 && strcmp (pwd->pw_passwd, "x") != 0 &&
@@ -676,13 +716,11 @@ main (int argc, char **argv)
 
   if (p_flag)
     {
-#define bin_to_ascii(c) ((c)>=38?((c)-38+'a'):(c)>=12?((c)-12+'A'):(c)+'.')
 #ifdef USE_CRACKLIB
       char *error_msg;
 #endif /* USE_CRACKLIB */
-      char *buf, salt[2], *p = NULL;
+      char *buf, salt[12], *p = NULL;
       int tries = 0;
-      time_t tm;
 
       buf = (char *) malloc (129);
 
@@ -733,9 +771,15 @@ main (int argc, char **argv)
 	    }
 	}
 
-      time (&tm);
-      salt[0] = bin_to_ascii (tm & 0x3f);
-      salt[1] = bin_to_ascii ((tm >> 6) & 0x3f);
+      if (!has_md5_passwd)
+	create_random_salt (salt, 2);
+      else
+	{
+	  /* The user already had a MD5 password, so it's safe to
+	   * use a MD5 password again */
+	  strcpy (salt, "$1$");
+	  create_random_salt (salt+3, 8);
+	}
 
       yppwd.newpw.pw_passwd = strdup (crypt (buf, salt));
     }