--- shadow-4.1.4.3/libmisc/chkname.c	2012-08-17 17:13:31.794491492 +0400
+++ shadow-4.1.4.3/libmisc/chkname.c	2012-08-17 17:15:18.615751619 +0400
@@ -49,15 +49,20 @@
 static bool is_valid_name (const char *name)
 {
 	/*
-	 * User/group names must match [a-z_][a-z0-9_-]*[$]
+	 * User/group names must match [a-zA-Z_][a-zA-Z0-9_-]*[$]
+	 * Allow user to use uppercase under his/her responsibility
 	 */
 	if (('\0' == *name) ||
-	    !((('a' <= *name) && ('z' >= *name)) || ('_' == *name))) {
+	    !((('a' <= *name) && ('z' >= *name)) ||
+	      (('A' <= *name) && ('Z' >= *name)) ||
+	      ('_' == *name)
+	     )) {
 		return false;
 	}
 
 	while ('\0' != *++name) {
 		if (!(( ('a' <= *name) && ('z' >= *name) ) ||
+		      ( ('A' <= *name) && ('Z' >= *name) ) ||
 		      ( ('0' <= *name) && ('9' >= *name) ) ||
 		      ('_' == *name) ||
 		      ('-' == *name) ||