1/* Copyright (C) 1996-2025 Free Software Foundation, Inc.
  2   This file is part of the GNU C Library.
  3
  4   The GNU C Library is free software; you can redistribute it and/or
  5   modify it under the terms of the GNU Lesser General Public
  6   License as published by the Free Software Foundation; either
  7   version 2.1 of the License, or (at your option) any later version.
  8
  9   The GNU C Library is distributed in the hope that it will be useful,
 10   but WITHOUT ANY WARRANTY; without even the implied warranty of
 11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 12   Lesser General Public License for more details.
 13
 14   You should have received a copy of the GNU Lesser General Public
 15   License along with the GNU C Library; if not, see
 16   <https://www.gnu.org/licenses/>.  */
 17
 18/* Declaration of types and functions for "shadow" storage of hashed
 19   passphrases.  The shadow database is like the user database, but is
 20   only accessible with special privileges, so that malicious users
 21   cannot retrieve everyone else's hashed passphrase to brute-force at
 22   their convenience.  */
 23
 24#ifndef _SHADOW_H
 25#define _SHADOW_H	1
 26
 27#include <features.h>
 28
 29#include <paths.h>
 30
 31#define __need_size_t
 32#include <stddef.h>
 33
 34#include <bits/types/FILE.h>
 35
 36/* Paths to the user database files.  */
 37#define	SHADOW _PATH_SHADOW
 38
 39
 40__BEGIN_DECLS
 41
 42/* A record in the shadow database.  */
 43struct spwd
 44  {
 45    char *sp_namp;		/* Login name.  */
 46    char *sp_pwdp;		/* Hashed passphrase.  */
 47    long int sp_lstchg;		/* Date of last change.  */
 48    long int sp_min;		/* Minimum number of days between changes.  */
 49    long int sp_max;		/* Maximum number of days between changes.  */
 50    long int sp_warn;		/* Number of days to warn user to change
 51				   the password.  */
 52    long int sp_inact;		/* Number of days the account may be
 53				   inactive.  */
 54    long int sp_expire;		/* Number of days since 1970-01-01 until
 55				   account expires.  */
 56    unsigned long int sp_flag;	/* Reserved.  */
 57  };
 58
 59
 60/* Open database for reading.
 61
 62   This function is not part of POSIX and therefore no official
 63   cancellation point.  But due to similarity with an POSIX interface
 64   or due to the implementation it is a cancellation point and
 65   therefore not marked with __THROW.  */
 66extern void setspent (void);
 67
 68/* Close database.
 69
 70   This function is not part of POSIX and therefore no official
 71   cancellation point.  But due to similarity with an POSIX interface
 72   or due to the implementation it is a cancellation point and
 73   therefore not marked with __THROW.  */
 74extern void endspent (void);
 75
 76/* Get next entry from database, perhaps after opening the file.
 77
 78   This function is not part of POSIX and therefore no official
 79   cancellation point.  But due to similarity with an POSIX interface
 80   or due to the implementation it is a cancellation point and
 81   therefore not marked with __THROW.  */
 82extern struct spwd *getspent (void);
 83
 84/* Get shadow entry matching NAME.
 85
 86   This function is not part of POSIX and therefore no official
 87   cancellation point.  But due to similarity with an POSIX interface
 88   or due to the implementation it is a cancellation point and
 89   therefore not marked with __THROW.  */
 90extern struct spwd *getspnam (const char *__name);
 91
 92/* Read shadow entry from STRING.
 93
 94   This function is not part of POSIX and therefore no official
 95   cancellation point.  But due to similarity with an POSIX interface
 96   or due to the implementation it is a cancellation point and
 97   therefore not marked with __THROW.  */
 98extern struct spwd *sgetspent (const char *__string);
 99
100/* Read next shadow entry from STREAM.
101
102   This function is not part of POSIX and therefore no official
103   cancellation point.  But due to similarity with an POSIX interface
104   or due to the implementation it is a cancellation point and
105   therefore not marked with __THROW.  */
106extern struct spwd *fgetspent (FILE *__stream);
107
108/* Write line containing shadow entry to stream.
109
110   This function is not part of POSIX and therefore no official
111   cancellation point.  But due to similarity with an POSIX interface
112   or due to the implementation it is a cancellation point and
113   therefore not marked with __THROW.  */
114extern int putspent (const struct spwd *__p, FILE *__stream);
115
116
117#ifdef __USE_MISC
118/* Reentrant versions of some of the functions above.
119
120   These functions are not part of POSIX and therefore no official
121   cancellation point.  But due to similarity with an POSIX interface
122   or due to the implementation they are cancellation points and
123   therefore not marked with __THROW.  */
124extern int getspent_r (struct spwd *__result_buf, char *__buffer,
125		       size_t __buflen, struct spwd **__result)
126	__attr_access ((__write_only__, 2, 3));
127
128extern int getspnam_r (const char *__name, struct spwd *__result_buf,
129		       char *__buffer, size_t __buflen,
130		       struct spwd **__result)
131	__attr_access ((__write_only__, 3, 4));
132
133extern int sgetspent_r (const char *__string, struct spwd *__result_buf,
134			char *__buffer, size_t __buflen,
135			struct spwd **__result)
136	__attr_access ((__write_only__, 3, 4));
137
138extern int fgetspent_r (FILE *__stream, struct spwd *__result_buf,
139			char *__buffer, size_t __buflen,
140			struct spwd **__result)
141	__attr_access ((__write_only__, 3, 4));
142#endif	/* misc */
143
144
145/* The simple locking functionality provided here is not suitable for
146   multi-threaded applications.  */
147
148/* Request exclusive access to /etc/passwd and /etc/shadow.  */
149extern int lckpwdf (void) __THROW;
150
151/* Release exclusive access to /etc/passwd and /etc/shadow.  */
152extern int ulckpwdf (void) __THROW;
153
154__END_DECLS
155
156#endif /* shadow.h */