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      1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
      2 /* dbus-credentials.c Credentials provable through authentication
      3  *
      4  * Copyright (C) 2007 Red Hat Inc.
      5  *
      6  * Licensed under the Academic Free License version 2.1
      7  *
      8  * This program is free software; you can redistribute it and/or modify
      9  * it under the terms of the GNU General Public License as published by
     10  * the Free Software Foundation; either version 2 of the License, or
     11  * (at your option) any later version.
     12  *
     13  * This program is distributed in the hope that it will be useful,
     14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
     15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     16  * GNU General Public License for more details.
     17  *
     18  * You should have received a copy of the GNU General Public License
     19  * along with this program; if not, write to the Free Software
     20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
     21  *
     22  */
     23 #include <config.h>
     24 #include <string.h>
     25 #include "dbus-credentials.h"
     26 #include "dbus-internals.h"
     27 
     28 /**
     29  * @defgroup DBusCredentials Credentials provable through authentication
     30  * @ingroup  DBusInternals
     31  * @brief DBusCredentials object
     32  *
     33  * Credentials are what you have to prove you have in order to
     34  * authenticate.  The main credentials right now are a unix user
     35  * account, a Windows user account, or a UNIX process ID.
     36  */
     37 
     38 /**
     39  * @defgroup DBusCredentialsInternals Credentials implementation details
     40  * @ingroup  DBusInternals
     41  * @brief DBusCredentials implementation details
     42  *
     43  * Private details of credentials code.
     44  *
     45  * @{
     46  */
     47 
     48 struct DBusCredentials {
     49   int refcount;
     50   dbus_uid_t unix_uid;
     51   dbus_pid_t unix_pid;
     52   char *windows_sid;
     53   void *adt_audit_data;
     54   dbus_int32_t adt_audit_data_size;
     55 };
     56 
     57 /** @} */
     58 
     59 /**
     60  * @addtogroup DBusCredentials
     61  * @{
     62  */
     63 
     64 /**
     65  * Creates a new credentials object.
     66  *
     67  * @returns the new object or #NULL if no memory
     68  */
     69 DBusCredentials*
     70 _dbus_credentials_new (void)
     71 {
     72   DBusCredentials *creds;
     73 
     74   creds = dbus_new (DBusCredentials, 1);
     75   if (creds == NULL)
     76     return NULL;
     77 
     78   creds->refcount = 1;
     79   creds->unix_uid = DBUS_UID_UNSET;
     80   creds->unix_pid = DBUS_PID_UNSET;
     81   creds->windows_sid = NULL;
     82   creds->adt_audit_data = NULL;
     83   creds->adt_audit_data_size = 0;
     84 
     85   return creds;
     86 }
     87 
     88 /**
     89  * Creates a new object with credentials (user ID and process ID) from the current process.
     90  * @returns the new object or #NULL if no memory
     91  */
     92 DBusCredentials*
     93 _dbus_credentials_new_from_current_process (void)
     94 {
     95   DBusCredentials *creds;
     96 
     97   creds = _dbus_credentials_new ();
     98   if (creds == NULL)
     99     return NULL;
    100 
    101   if (!_dbus_credentials_add_from_current_process (creds))
    102     {
    103       _dbus_credentials_unref (creds);
    104       return NULL;
    105     }
    106 
    107   return creds;
    108 }
    109 
    110 /**
    111  * Increment refcount on credentials.
    112  *
    113  * @param credentials the object
    114  */
    115 void
    116 _dbus_credentials_ref (DBusCredentials *credentials)
    117 {
    118   _dbus_assert (credentials->refcount > 0);
    119   credentials->refcount += 1;
    120 }
    121 
    122 /**
    123  * Decrement refcount on credentials.
    124  *
    125  * @param credentials the object
    126  */
    127 void
    128 _dbus_credentials_unref (DBusCredentials    *credentials)
    129 {
    130   _dbus_assert (credentials->refcount > 0);
    131 
    132   credentials->refcount -= 1;
    133   if (credentials->refcount == 0)
    134     {
    135       dbus_free (credentials->windows_sid);
    136       dbus_free (credentials->adt_audit_data);
    137       dbus_free (credentials);
    138     }
    139 }
    140 
    141 /**
    142  * Add a UNIX process ID to the credentials.
    143  *
    144  * @param credentials the object
    145  * @param pid the process ID
    146  * @returns #FALSE if no memory
    147  */
    148 dbus_bool_t
    149 _dbus_credentials_add_unix_pid (DBusCredentials    *credentials,
    150                                 dbus_pid_t          pid)
    151 {
    152   credentials->unix_pid = pid;
    153   return TRUE;
    154 }
    155 
    156 /**
    157  * Add a UNIX user ID to the credentials.
    158  *
    159  * @param credentials the object
    160  * @param uid the user ID
    161  * @returns #FALSE if no memory
    162  */
    163 dbus_bool_t
    164 _dbus_credentials_add_unix_uid(DBusCredentials    *credentials,
    165                                dbus_uid_t          uid)
    166 {
    167   credentials->unix_uid = uid;
    168   return TRUE;
    169 
    170 }
    171 
    172 /**
    173  * Add a Windows user SID to the credentials.
    174  *
    175  * @param credentials the object
    176  * @param windows_sid the user SID
    177  * @returns #FALSE if no memory
    178  */
    179 dbus_bool_t
    180 _dbus_credentials_add_windows_sid (DBusCredentials    *credentials,
    181                                    const char         *windows_sid)
    182 {
    183   char *copy;
    184 
    185   copy = _dbus_strdup (windows_sid);
    186   if (copy == NULL)
    187     return FALSE;
    188 
    189   dbus_free (credentials->windows_sid);
    190   credentials->windows_sid = copy;
    191 
    192   return TRUE;
    193 }
    194 
    195 /**
    196  * Add ADT audit data to the credentials.
    197  *
    198  * @param credentials the object
    199  * @param audit_data the audit data
    200  * @param size the length of audit data
    201  * @returns #FALSE if no memory
    202  */
    203 dbus_bool_t
    204 _dbus_credentials_add_adt_audit_data (DBusCredentials    *credentials,
    205                                       void               *audit_data,
    206                                       dbus_int32_t        size)
    207 {
    208   void *copy;
    209   copy = _dbus_memdup (audit_data, size);
    210   if (copy == NULL)
    211     return FALSE;
    212 
    213   dbus_free (credentials->adt_audit_data);
    214   credentials->adt_audit_data = copy;
    215   credentials->adt_audit_data_size = size;
    216 
    217   return TRUE;
    218 }
    219 
    220 /**
    221  * Checks whether the given credential is present.
    222  *
    223  * @param credentials the object
    224  * @param type the credential to check for
    225  * @returns #TRUE if the credential is present
    226  */
    227 dbus_bool_t
    228 _dbus_credentials_include (DBusCredentials    *credentials,
    229                            DBusCredentialType  type)
    230 {
    231   switch (type)
    232     {
    233     case DBUS_CREDENTIAL_UNIX_PROCESS_ID:
    234       return credentials->unix_pid != DBUS_PID_UNSET;
    235     case DBUS_CREDENTIAL_UNIX_USER_ID:
    236       return credentials->unix_uid != DBUS_UID_UNSET;
    237     case DBUS_CREDENTIAL_WINDOWS_SID:
    238       return credentials->windows_sid != NULL;
    239     case DBUS_CREDENTIAL_ADT_AUDIT_DATA_ID:
    240       return credentials->adt_audit_data != NULL;
    241     }
    242 
    243   _dbus_assert_not_reached ("Unknown credential enum value");
    244   return FALSE;
    245 }
    246 
    247 /**
    248  * Gets the UNIX process ID in the credentials, or #DBUS_PID_UNSET if
    249  * the credentials object doesn't contain a process ID.
    250  *
    251  * @param credentials the object
    252  * @returns UNIX process ID
    253  */
    254 dbus_pid_t
    255 _dbus_credentials_get_unix_pid (DBusCredentials    *credentials)
    256 {
    257   return credentials->unix_pid;
    258 }
    259 
    260 /**
    261  * Gets the UNIX user ID in the credentials, or #DBUS_UID_UNSET if
    262  * the credentials object doesn't contain a user ID.
    263  *
    264  * @param credentials the object
    265  * @returns UNIX user ID
    266  */
    267 dbus_uid_t
    268 _dbus_credentials_get_unix_uid (DBusCredentials    *credentials)
    269 {
    270   return credentials->unix_uid;
    271 }
    272 
    273 /**
    274  * Gets the Windows user SID in the credentials, or #NULL if
    275  * the credentials object doesn't contain a Windows user SID.
    276  *
    277  * @param credentials the object
    278  * @returns Windows user SID
    279  */
    280 const char*
    281 _dbus_credentials_get_windows_sid (DBusCredentials    *credentials)
    282 {
    283   return credentials->windows_sid;
    284 }
    285 
    286 /**
    287  * Gets the ADT audit data in the credentials, or #NULL if
    288  * the credentials object doesn't contain ADT audit data.
    289  *
    290  * @param credentials the object
    291  * @returns Solaris ADT audit data
    292  */
    293 void *
    294 _dbus_credentials_get_adt_audit_data (DBusCredentials    *credentials)
    295 {
    296   return credentials->adt_audit_data;
    297 }
    298 
    299 /**
    300  * Gets the ADT audit data size in the credentials, or 0 if
    301  * the credentials object doesn't contain ADT audit data.
    302  *
    303  * @param credentials the object
    304  * @returns Solaris ADT audit data size
    305  */
    306 dbus_int32_t
    307 _dbus_credentials_get_adt_audit_data_size (DBusCredentials    *credentials)
    308 {
    309   return credentials->adt_audit_data_size;
    310 }
    311 
    312 /**
    313  * Checks whether the first credentials object contains
    314  * all the credentials found in the second credentials object.
    315  *
    316  * @param credentials the object
    317  * @param possible_subset see if credentials in here are also in the first arg
    318  * @returns #TRUE if second arg is contained in first
    319  */
    320 dbus_bool_t
    321 _dbus_credentials_are_superset (DBusCredentials    *credentials,
    322                                 DBusCredentials    *possible_subset)
    323 {
    324   return
    325     (possible_subset->unix_pid == DBUS_PID_UNSET ||
    326      possible_subset->unix_pid == credentials->unix_pid) &&
    327     (possible_subset->unix_uid == DBUS_UID_UNSET ||
    328      possible_subset->unix_uid == credentials->unix_uid) &&
    329     (possible_subset->windows_sid == NULL ||
    330      (credentials->windows_sid && strcmp (possible_subset->windows_sid,
    331                                           credentials->windows_sid) == 0)) &&
    332     (possible_subset->adt_audit_data == NULL ||
    333      (credentials->adt_audit_data && memcmp (possible_subset->adt_audit_data,
    334                                              credentials->adt_audit_data,
    335                                              credentials->adt_audit_data_size) == 0));
    336 }
    337 
    338 /**
    339  * Checks whether a credentials object contains anything.
    340  *
    341  * @param credentials the object
    342  * @returns #TRUE if there are no credentials in the object
    343  */
    344 dbus_bool_t
    345 _dbus_credentials_are_empty (DBusCredentials    *credentials)
    346 {
    347   return
    348     credentials->unix_pid == DBUS_PID_UNSET &&
    349     credentials->unix_uid == DBUS_UID_UNSET &&
    350     credentials->windows_sid == NULL &&
    351     credentials->adt_audit_data == NULL;
    352 }
    353 
    354 /**
    355  * Checks whether a credentials object contains a user identity.
    356  *
    357  * @param credentials the object
    358  * @returns #TRUE if there are no user identities in the object
    359  */
    360 dbus_bool_t
    361 _dbus_credentials_are_anonymous (DBusCredentials    *credentials)
    362 {
    363   return
    364     credentials->unix_uid == DBUS_UID_UNSET &&
    365     credentials->windows_sid == NULL;
    366 }
    367 
    368 /**
    369  * Merge all credentials found in the second object into the first object,
    370  * overwriting the first object if there are any overlaps.
    371  *
    372  * @param credentials the object
    373  * @param other_credentials credentials to merge
    374  * @returns #FALSE if no memory
    375  */
    376 dbus_bool_t
    377 _dbus_credentials_add_credentials (DBusCredentials    *credentials,
    378                                    DBusCredentials    *other_credentials)
    379 {
    380   return
    381     _dbus_credentials_add_credential (credentials,
    382                                       DBUS_CREDENTIAL_UNIX_PROCESS_ID,
    383                                       other_credentials) &&
    384     _dbus_credentials_add_credential (credentials,
    385                                       DBUS_CREDENTIAL_UNIX_USER_ID,
    386                                       other_credentials) &&
    387     _dbus_credentials_add_credential (credentials,
    388                                       DBUS_CREDENTIAL_ADT_AUDIT_DATA_ID,
    389                                       other_credentials) &&
    390     _dbus_credentials_add_credential (credentials,
    391                                       DBUS_CREDENTIAL_WINDOWS_SID,
    392                                       other_credentials);
    393 }
    394 
    395 /**
    396  * Merge the given credential found in the second object into the first object,
    397  * overwriting the first object's value for that credential.
    398  *
    399  * Does nothing if the second object does not contain the specified credential.
    400  * i.e., will never delete a credential from the first object.
    401  *
    402  * @param credentials the object
    403  * @param which the credential to overwrite
    404  * @param other_credentials credentials to merge
    405  * @returns #FALSE if no memory
    406  */
    407 dbus_bool_t
    408 _dbus_credentials_add_credential (DBusCredentials    *credentials,
    409                                   DBusCredentialType  which,
    410                                   DBusCredentials    *other_credentials)
    411 {
    412   if (which == DBUS_CREDENTIAL_UNIX_PROCESS_ID &&
    413       other_credentials->unix_pid != DBUS_PID_UNSET)
    414     {
    415       if (!_dbus_credentials_add_unix_pid (credentials, other_credentials->unix_pid))
    416         return FALSE;
    417     }
    418   else if (which == DBUS_CREDENTIAL_UNIX_USER_ID &&
    419            other_credentials->unix_uid != DBUS_UID_UNSET)
    420     {
    421       if (!_dbus_credentials_add_unix_uid (credentials, other_credentials->unix_uid))
    422         return FALSE;
    423     }
    424   else if (which == DBUS_CREDENTIAL_WINDOWS_SID &&
    425            other_credentials->windows_sid != NULL)
    426     {
    427       if (!_dbus_credentials_add_windows_sid (credentials, other_credentials->windows_sid))
    428         return FALSE;
    429     }
    430   else if (which == DBUS_CREDENTIAL_ADT_AUDIT_DATA_ID &&
    431            other_credentials->adt_audit_data != NULL)
    432     {
    433       if (!_dbus_credentials_add_adt_audit_data (credentials, other_credentials->adt_audit_data, other_credentials->adt_audit_data_size))
    434         return FALSE;
    435     }
    436 
    437   return TRUE;
    438 }
    439 
    440 /**
    441  * Clear all credentials in the object.
    442  *
    443  * @param credentials the object
    444  */
    445 void
    446 _dbus_credentials_clear (DBusCredentials    *credentials)
    447 {
    448   credentials->unix_pid = DBUS_PID_UNSET;
    449   credentials->unix_uid = DBUS_UID_UNSET;
    450   dbus_free (credentials->windows_sid);
    451   credentials->windows_sid = NULL;
    452   dbus_free (credentials->adt_audit_data);
    453   credentials->adt_audit_data = NULL;
    454   credentials->adt_audit_data_size = 0;
    455 }
    456 
    457 /**
    458  * Copy a credentials object.
    459  *
    460  * @param credentials the object
    461  * @returns the copy or #NULL
    462  */
    463 DBusCredentials*
    464 _dbus_credentials_copy (DBusCredentials    *credentials)
    465 {
    466   DBusCredentials *copy;
    467 
    468   copy = _dbus_credentials_new ();
    469   if (copy == NULL)
    470     return NULL;
    471 
    472   if (!_dbus_credentials_add_credentials (copy, credentials))
    473     {
    474       _dbus_credentials_unref (copy);
    475       return NULL;
    476     }
    477 
    478   return copy;
    479 }
    480 
    481 /**
    482  * Check whether the user-identifying credentials in two credentials
    483  * objects are identical. Credentials that are not related to the
    484  * user are ignored, but any kind of user ID credentials must be the
    485  * same (UNIX user ID, Windows user SID, etc.) and present in both
    486  * objects for the function to return #TRUE.
    487  *
    488  * @param credentials the object
    489  * @param other_credentials credentials to compare
    490  * @returns #TRUE if the two credentials refer to the same user
    491  */
    492 dbus_bool_t
    493 _dbus_credentials_same_user (DBusCredentials    *credentials,
    494                              DBusCredentials    *other_credentials)
    495 {
    496   /* both windows and unix user must be the same (though pretty much
    497    * in all conceivable cases, one will be unset)
    498    */
    499   return credentials->unix_uid == other_credentials->unix_uid &&
    500     ((!(credentials->windows_sid || other_credentials->windows_sid)) ||
    501      (credentials->windows_sid && other_credentials->windows_sid &&
    502       strcmp (credentials->windows_sid, other_credentials->windows_sid) == 0));
    503 }
    504 
    505 /**
    506  * Convert the credentials in this object to a human-readable
    507  * string format, and append to the given string.
    508  *
    509  * @param credentials the object
    510  * @param string append to this string
    511  * @returns #FALSE if no memory
    512  */
    513 dbus_bool_t
    514 _dbus_credentials_to_string_append (DBusCredentials    *credentials,
    515                                     DBusString         *string)
    516 {
    517   dbus_bool_t join;
    518 
    519   join = FALSE;
    520   if (credentials->unix_uid != DBUS_UID_UNSET)
    521     {
    522       if (!_dbus_string_append_printf (string, "uid=" DBUS_UID_FORMAT, credentials->unix_uid))
    523         goto oom;
    524       join = TRUE;
    525     }
    526   if (credentials->unix_pid != DBUS_PID_UNSET)
    527     {
    528       if (!_dbus_string_append_printf (string, "%spid=" DBUS_PID_FORMAT, join ? " " : "", credentials->unix_pid))
    529         goto oom;
    530       join = TRUE;
    531     }
    532   else
    533     join = FALSE;
    534   if (credentials->windows_sid != NULL)
    535     {
    536       if (!_dbus_string_append_printf (string, "%ssid=%s", join ? " " : "", credentials->windows_sid))
    537         goto oom;
    538       join = TRUE;
    539     }
    540   else
    541     join = FALSE;
    542 
    543   return TRUE;
    544 oom:
    545   return FALSE;
    546 }
    547 
    548 /** @} */
    549 
    550 /* tests in dbus-credentials-util.c */
    551