bc0151d4d3
The _SC_LOGIN_NAME_MAX value includes space for the NUL byte. The
length of name must smaller than this value to be valid.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Cherry-picked-from: 403a2e3771 ("lib/chkname.c: Take NUL byte into account")
Link: <https://github.com/shadow-maint/shadow/pull/935>
Cc: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
103 lines
2.2 KiB
C
103 lines
2.2 KiB
C
/*
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* SPDX-FileCopyrightText: 1990 - 1994, Julianne Frances Haugh
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* SPDX-FileCopyrightText: 1996 - 2000, Marek Michałkiewicz
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* SPDX-FileCopyrightText: 2001 - 2005, Tomasz Kłoczko
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* SPDX-FileCopyrightText: 2005 - 2008, Nicolas François
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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/*
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* is_valid_user_name(), is_valid_group_name() - check the new user/group
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* name for validity;
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* return values:
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* true - OK
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* false - bad name
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*/
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#include <config.h>
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#ident "$Id$"
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#include <ctype.h>
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#include "defines.h"
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#include "chkname.h"
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int allow_bad_names = false;
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static bool is_valid_name (const char *name)
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{
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if (allow_bad_names) {
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return true;
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}
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/*
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* User/group names must match gnu e-regex:
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* [a-zA-Z0-9_.][a-zA-Z0-9_.-]{0,30}[a-zA-Z0-9_.$-]?
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*
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* as a non-POSIX, extension, allow "$" as the last char for
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* sake of Samba 3.x "add machine script"
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*
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* Also do not allow fully numeric names or just "." or "..".
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*/
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int numeric;
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if ('\0' == *name ||
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('.' == *name && (('.' == name[1] && '\0' == name[2]) ||
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'\0' == name[1])) ||
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!((*name >= 'a' && *name <= 'z') ||
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(*name >= 'A' && *name <= 'Z') ||
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(*name >= '0' && *name <= '9') ||
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*name == '_' ||
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*name == '.')) {
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return false;
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}
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numeric = isdigit(*name);
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while ('\0' != *++name) {
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if (!((*name >= 'a' && *name <= 'z') ||
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(*name >= 'A' && *name <= 'Z') ||
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(*name >= '0' && *name <= '9') ||
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*name == '_' ||
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*name == '.' ||
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*name == '-' ||
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(*name == '$' && name[1] == '\0')
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)) {
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return false;
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}
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numeric &= isdigit(*name);
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}
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return !numeric;
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}
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bool is_valid_user_name (const char *name)
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{
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size_t maxlen;
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/*
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* User names length are limited by the kernel
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*/
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maxlen = sysconf(_SC_LOGIN_NAME_MAX);
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if (strlen(name) >= maxlen)
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return false;
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return is_valid_name (name);
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}
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bool is_valid_group_name (const char *name)
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{
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/*
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* Arbitrary limit for group names.
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* HP-UX 10 limits to 16 characters
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*/
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if ( (GROUP_NAME_MAX_LENGTH > 0)
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&& (strlen (name) > GROUP_NAME_MAX_LENGTH)) {
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return false;
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}
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return is_valid_name (name);
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}
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