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 #include <bits/types/FILE.h>
  32 #include <bits/types/size_t.h>
  33
  34 /* Paths to the user database files.  */
  35 #define SHADOW _PATH_SHADOW
  36
  37
  38 __BEGIN_DECLS
  39
  40 /* A record in the shadow database.  */
  41 struct spwd
  42   {
  43     char *sp_namp;              /* Login name.  */
  44     char *sp_pwdp;              /* Hashed passphrase.  */
  45     long int sp_lstchg;         /* Date of last change.  */
  46     long int sp_min;            /* Minimum number of days between changes.  */
  47     long int sp_max;            /* Maximum number of days between changes.  */
  48     long int sp_warn;           /* Number of days to warn user to change
  49                                    the password.  */
  50     long int sp_inact;          /* Number of days the account may be
  51                                    inactive.  */
  52     long int sp_expire;         /* Number of days since 1970-01-01 until
  53                                    account expires.  */
  54     unsigned long int sp_flag;  /* Reserved.  */
  55   };
  56
  57
  58 /* Open database for reading.
  59
  60    This function is not part of POSIX and therefore no official
  61    cancellation point.  But due to similarity with an POSIX interface
  62    or due to the implementation it is a cancellation point and
  63    therefore not marked with __THROW.  */
  64 extern void setspent (void);
  65
  66 /* Close database.
  67
  68    This function is not part of POSIX and therefore no official
  69    cancellation point.  But due to similarity with an POSIX interface
  70    or due to the implementation it is a cancellation point and
  71    therefore not marked with __THROW.  */
  72 extern void endspent (void);
  73
  74 /* Get next entry from database, perhaps after opening the file.
  75
  76    This function is not part of POSIX and therefore no official
  77    cancellation point.  But due to similarity with an POSIX interface
  78    or due to the implementation it is a cancellation point and
  79    therefore not marked with __THROW.  */
  80 extern struct spwd *getspent (void);
  81
  82 /* Get shadow entry matching NAME.
  83
  84    This function is not part of POSIX and therefore no official
  85    cancellation point.  But due to similarity with an POSIX interface
  86    or due to the implementation it is a cancellation point and
  87    therefore not marked with __THROW.  */
  88 extern struct spwd *getspnam (const char *__name);
  89
  90 /* Read shadow entry from STRING.
  91
  92    This function is not part of POSIX and therefore no official
  93    cancellation point.  But due to similarity with an POSIX interface
  94    or due to the implementation it is a cancellation point and
  95    therefore not marked with __THROW.  */
  96 extern struct spwd *sgetspent (const char *__string);
  97
  98 /* Read next shadow entry from STREAM.
  99
 100    This function is not part of POSIX and therefore no official
 101    cancellation point.  But due to similarity with an POSIX interface
 102    or due to the implementation it is a cancellation point and
 103    therefore not marked with __THROW.  */
 104 extern struct spwd *fgetspent (FILE *__stream);
 105
 106 /* Write line containing shadow entry to stream.
 107
 108    This function is not part of POSIX and therefore no official
 109    cancellation point.  But due to similarity with an POSIX interface
 110    or due to the implementation it is a cancellation point and
 111    therefore not marked with __THROW.  */
 112 extern int putspent (const struct spwd *__p, FILE *__stream);
 113
 114
 115 #ifdef __USE_MISC
 116 /* Reentrant versions of some of the functions above.
 117
 118    These functions are not part of POSIX and therefore no official
 119    cancellation point.  But due to similarity with an POSIX interface
 120    or due to the implementation they are cancellation points and
 121    therefore not marked with __THROW.  */
 122 extern int getspent_r (struct spwd *__result_buf, char *__buffer,
 123                        size_t __buflen, struct spwd **__result);
 124
 125 extern int getspnam_r (const char *__name, struct spwd *__result_buf,
 126                        char *__buffer, size_t __buflen,
 127                        struct spwd **__result);
 128
 129 extern int sgetspent_r (const char *__string, struct spwd *__result_buf,
 130                         char *__buffer, size_t __buflen,
 131                         struct spwd **__result);
 132
 133 extern int fgetspent_r (FILE *__stream, struct spwd *__result_buf,
 134                         char *__buffer, size_t __buflen,
 135                         struct spwd **__result);
 136 #endif  /* misc */
 137
 138
 139 /* The simple locking functionality provided here is not suitable for
 140    multi-threaded applications.  */
 141
 142 /* Request exclusive access to /etc/passwd and /etc/shadow.  */
 143 extern int lckpwdf (void) __THROW;
 144
 145 /* Release exclusive access to /etc/passwd and /etc/shadow.  */
 146 extern int ulckpwdf (void) __THROW;
 147
 148 __END_DECLS
 149
 150 #endif /* shadow.h */