mirror of
https://github.com/sheumann/hush.git
synced 2024-12-25 18:33:06 +00:00
7485086f1e
function old new delta die_if_bad_username 77 97 +20 Based on patches from Tito. The changes are: better comments we disallow '@' now - in practice such usernames will be unusable use of the portable filename character set plus '$' don't use isalnum as it allows non-ASCII letters in legacy 8-bit locales (pointed out by Rich Felker) enforce maximum length of LOGIN_NAME_MAX (including NUL) don't allow '$', '.', and '-' as first char don't print the illegal char in error message as if it is a wide char it will be unreadable print the position of the illegal character Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
63 lines
1.7 KiB
C
63 lines
1.7 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* Check user and group names for illegal characters
|
|
*
|
|
* Copyright (C) 2008 Tito Ragusa <farmatito@tiscali.it>
|
|
*
|
|
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
|
|
*/
|
|
|
|
#include "libbb.h"
|
|
|
|
/* To avoid problems, the username should consist only of
|
|
* letters, digits, underscores, periods, at signs and dashes,
|
|
* and not start with a dash (as defined by IEEE Std 1003.1-2001).
|
|
* For compatibility with Samba machine accounts $ is also supported
|
|
* at the end of the username.
|
|
*/
|
|
|
|
void FAST_FUNC die_if_bad_username(const char *name)
|
|
{
|
|
const char *start = name;
|
|
|
|
/* 1st char being dash or dot isn't valid:
|
|
* for example, name like ".." can make adduser
|
|
* chown "/home/.." recursively - NOT GOOD.
|
|
* Name of just a single "$" is also rejected.
|
|
*/
|
|
goto skip;
|
|
|
|
do {
|
|
unsigned char ch;
|
|
|
|
/* These chars are valid unless they are at the 1st pos: */
|
|
if (*name == '-'
|
|
|| *name == '.'
|
|
/* $ is allowed if it's the last char: */
|
|
|| (*name == '$' && !name[1])
|
|
) {
|
|
continue;
|
|
}
|
|
skip:
|
|
ch = *name;
|
|
if (ch == '_'
|
|
/* || ch == '@' -- we disallow this too. Think about "user@host" */
|
|
/* open-coded isalnum: */
|
|
|| (ch >= '0' && ch <= '9')
|
|
|| ((ch|0x20) >= 'a' && (ch|0x20) <= 'z')
|
|
) {
|
|
continue;
|
|
}
|
|
bb_error_msg_and_die("illegal character with code %u at position %u",
|
|
(unsigned)ch, (unsigned)(name - start));
|
|
} while (*++name);
|
|
|
|
/* The minimum size of the login name is one char or two if
|
|
* last char is the '$'. Violations of this are caught above.
|
|
* The maximum size of the login name is LOGIN_NAME_MAX
|
|
* including the terminating null byte.
|
|
*/
|
|
if (name - start >= LOGIN_NAME_MAX)
|
|
bb_error_msg_and_die("name is too long");
|
|
}
|