pcsc-lite  1.8.11
auth.c
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1 /*
2  * MUSCLE SmartCard Development ( http://pcsclite.alioth.debian.org/pcsclite.html )
3  *
4  * Copyright (C) 2013 Red Hat
5  *
6  * All rights reserved.
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  * notice, this list of conditions and the following disclaimer.
13  *
14  * 2. Redistributions in binary form must reproduce the above copyright
15  * notice, this list of conditions and the following disclaimer in the
16  * documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22  * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
25  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
28  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
29  * DAMAGE.
30  *
31  * Author: Nikos Mavrogiannopoulos <nmav@redhat.com>
32  */
33 
42 #include "config.h"
43 #define _GNU_SOURCE
44 #include <sys/types.h>
45 #include <sys/socket.h>
46 #include <sys/ioctl.h>
47 #include <sys/un.h>
48 #include <stdio.h>
49 #include "debuglog.h"
50 
51 #include <errno.h>
52 
53 #if defined(HAVE_POLKIT) && defined(SO_PEERCRED)
54 
55 #include <polkit/polkit.h>
56 
57 /* Returns non zero when the client is authorized */
58 unsigned IsClientAuthorized(int socket, const char* action, const char* reader)
59 {
60  struct ucred cr;
61  socklen_t cr_len;
62  int ret;
63  PolkitSubject *subject;
64  PolkitAuthority *authority;
65  PolkitAuthorizationResult *result;
66  PolkitDetails *details;
67  GError *error = NULL;
68  char action_name[128];
69 
70  snprintf(action_name, sizeof(action_name), "org.debian.pcsc-lite.%s", action);
71 
72  cr_len = sizeof(cr);
73  ret = getsockopt(socket, SOL_SOCKET, SO_PEERCRED, &cr, &cr_len);
74  if (ret == -1)
75  {
76  int e = errno;
77  Log2(PCSC_LOG_CRITICAL,
78  "Error obtaining client process credentials: %s", strerror(e));
79  return 0;
80  }
81 
82  authority = polkit_authority_get_sync(NULL, NULL);
83  if (authority == NULL)
84  {
85  Log1(PCSC_LOG_CRITICAL, "polkit_authority_get_sync failed");
86  return 0;
87  }
88 
89  subject = polkit_unix_process_new_for_owner(cr.pid, 0, cr.uid);
90  if (subject == NULL)
91  {
92  Log1(PCSC_LOG_CRITICAL, "polkit_unix_process_new_for_owner failed");
93  ret = 0;
94  goto cleanup1;
95  }
96 
97  details = polkit_details_new();
98  if (details == NULL)
99  {
100  Log1(PCSC_LOG_CRITICAL, "polkit_details_new failed");
101  ret = 0;
102  goto cleanup0;
103  }
104 
105  if (reader != NULL)
106  polkit_details_insert(details, "reader", reader);
107 
108  result = polkit_authority_check_authorization_sync(authority, subject,
109  action_name, details,
110  POLKIT_CHECK_AUTHORIZATION_FLAGS_NONE,
111  NULL,
112  &error);
113 
114  if (result == NULL)
115  {
116  Log2(PCSC_LOG_CRITICAL, "Error in authorization: %s", error->message);
117  g_error_free(error);
118  ret = 0;
119  }
120  else
121  {
122  if (polkit_authorization_result_get_is_authorized(result))
123  {
124  ret = 1;
125  }
126  else
127  {
128  ret = 0;
129  }
130  }
131 
132  if (ret == 0)
133  {
134  Log4(PCSC_LOG_CRITICAL,
135  "Process %u (user: %u) is NOT authorized for action: %s",
136  (unsigned)cr.pid, (unsigned)cr.uid, action);
137  }
138 
139  g_object_unref(subject);
140 cleanup0:
141  g_object_unref(details);
142 cleanup1:
143  g_object_unref(authority);
144 
145  return ret;
146 }
147 
148 #else
149 
150 int IsClientAuthorized(int socket, const char* action, const char* reader)
151 {
152  return 1;
153 }
154 
155 #endif
This handles debugging.