shadow/shadow.h

   1 /* Copyright (C) 1996-2020 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.  */
  43 struct 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.  */
  66 extern 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.  */
  74 extern 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.  */
  82 extern 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.  */
  90 extern 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.  */
  98 extern 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.  */
 106 extern 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.  */
 114 extern 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.  */
 124 extern int getspent_r (struct spwd *__result_buf, char *__buffer,
 125                        size_t __buflen, struct spwd **__result);
 126
 127 extern int getspnam_r (const char *__name, struct spwd *__result_buf,
 128                        char *__buffer, size_t __buflen,
 129                        struct spwd **__result);
 130
 131 extern int sgetspent_r (const char *__string, struct spwd *__result_buf,
 132                         char *__buffer, size_t __buflen,
 133                         struct spwd **__result);
 134
 135 extern int fgetspent_r (FILE *__stream, struct spwd *__result_buf,
 136                         char *__buffer, size_t __buflen,
 137                         struct spwd **__result);
 138 #endif  /* misc */
 139
 140
 141 /* The simple locking functionality provided here is not suitable for
 142    multi-threaded applications.  */
 143
 144 /* Request exclusive access to /etc/passwd and /etc/shadow.  */
 145 extern int lckpwdf (void) __THROW;
 146
 147 /* Release exclusive access to /etc/passwd and /etc/shadow.  */
 148 extern int ulckpwdf (void) __THROW;
 149
 150 __END_DECLS
 151
 152 #endif /* shadow.h */