From b182c52d63bea0f08e1befcec5c3797dd97cdef5 Mon Sep 17 00:00:00 2001
From: Alexander Kanavin <alex@linutronix.de>
Date: Tue, 16 Aug 2022 13:46:22 +0200
Subject: [PATCH] shadow: use relaxed usernames

The groupadd from shadow does not allow upper case group names, the
same is true for the upstream shadow. But distributions like
Debian/Ubuntu/CentOS has their own way to cope with this problem,
this patch is picked up from CentOS release 7.0 to relax the usernames
restrictions to allow the upper case group names, and the relaxation is
POSIX compliant because POSIX indicate that usernames are composed of
characters from the portable filename character set [A-Za-z0-9._-].

Upstream-Status: Submitted [https://github.com/shadow-maint/shadow/pull/551]

Signed-off-by: Shan Hai <shan.hai@windriver.com>
Signed-off-by: Alexander Kanavin <alex@linutronix.de>
---
 libmisc/chkname.c  | 29 ++++++++++++++++++-----------
 man/groupadd.8.xml |  6 ------
 man/useradd.8.xml  |  6 ------
 3 files changed, 18 insertions(+), 23 deletions(-)

diff --git a/libmisc/chkname.c b/libmisc/chkname.c
index cb002a14..c0306c5a 100644
--- a/libmisc/chkname.c
+++ b/libmisc/chkname.c
@@ -32,21 +32,28 @@ static bool is_valid_name (const char *name)
 	}
 
 	/*
-	 * User/group names must match [a-z_][a-z0-9_-]*[$]
-	 */
-
-	if (('\0' == *name) ||
-	    !((('a' <= *name) && ('z' >= *name)) || ('_' == *name))) {
+         * User/group names must match gnu e-regex:
+         *    [a-zA-Z0-9_.][a-zA-Z0-9_.-]{0,30}[a-zA-Z0-9_.$-]?
+         *
+         * as a non-POSIX, extension, allow "$" as the last char for
+         * sake of Samba 3.x "add machine script"
+         */
+	if ( ('\0' == *name) ||
+             !((*name >= 'a' && *name <= 'z') ||
+               (*name >= 'A' && *name <= 'Z') ||
+               (*name >= '0' && *name <= '9') ||
+               (*name == '_') || (*name == '.') 
+	      )) {
 		return false;
 	}
 
 	while ('\0' != *++name) {
-		if (!(( ('a' <= *name) && ('z' >= *name) ) ||
-		      ( ('0' <= *name) && ('9' >= *name) ) ||
-		      ('_' == *name) ||
-		      ('-' == *name) ||
-		      ( ('$' == *name) && ('\0' == *(name + 1)) )
-		     )) {
+                if (!(  (*name >= 'a' && *name <= 'z') ||
+                        (*name >= 'A' && *name <= 'Z') ||
+                        (*name >= '0' && *name <= '9') ||
+                        (*name == '_') || (*name == '.') || (*name == '-') ||
+                        (*name == '$' && *(name + 1) == '\0') 
+                     )) {
 			return false;
 		}
 	}
diff --git a/man/groupadd.8.xml b/man/groupadd.8.xml
index 26671f92..3eacaa09 100644
--- a/man/groupadd.8.xml
+++ b/man/groupadd.8.xml
@@ -63,12 +63,6 @@
       values from the system. The new group will be entered into the system
       files as needed.
     </para>
-     <para>
-       Groupnames must start with a lower case letter or an underscore,
-       followed by lower case letters, digits, underscores, or dashes.
-       They can end with a dollar sign.
-       In regular expression terms: [a-z_][a-z0-9_-]*[$]?
-     </para>
      <para>
        Groupnames may only be up to &GROUP_NAME_MAX_LENGTH; characters long.
      </para>
diff --git a/man/useradd.8.xml b/man/useradd.8.xml
index c7f95b47..e056d141 100644
--- a/man/useradd.8.xml
+++ b/man/useradd.8.xml
@@ -691,12 +691,6 @@
       the user account creation request.
     </para>
 
-    <para>
-      Usernames must start with a lower case letter or an underscore,
-      followed by lower case letters, digits, underscores, or dashes.
-      They can end with a dollar sign.
-      In regular expression terms: [a-z_][a-z0-9_-]*[$]?
-    </para>
     <para>
       Usernames may only be up to 32 characters long.
     </para>
-- 
2.30.2