~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/security/keys/user_defined.c

Version: ~ [ linux-5.3-rc4 ] ~ [ linux-5.2.8 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.66 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.138 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.189 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.189 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.71 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /* user_defined.c: user defined key type
  2  *
  3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
  4  * Written by David Howells (dhowells@redhat.com)
  5  *
  6  * This program is free software; you can redistribute it and/or
  7  * modify it under the terms of the GNU General Public License
  8  * as published by the Free Software Foundation; either version
  9  * 2 of the License, or (at your option) any later version.
 10  */
 11 
 12 #include <linux/module.h>
 13 #include <linux/init.h>
 14 #include <linux/slab.h>
 15 #include <linux/seq_file.h>
 16 #include <linux/err.h>
 17 #include <keys/user-type.h>
 18 #include <asm/uaccess.h>
 19 #include "internal.h"
 20 
 21 static int logon_vet_description(const char *desc);
 22 
 23 /*
 24  * user defined keys take an arbitrary string as the description and an
 25  * arbitrary blob of data as the payload
 26  */
 27 struct key_type key_type_user = {
 28         .name           = "user",
 29         .instantiate    = user_instantiate,
 30         .update         = user_update,
 31         .match          = user_match,
 32         .revoke         = user_revoke,
 33         .destroy        = user_destroy,
 34         .describe       = user_describe,
 35         .read           = user_read,
 36 };
 37 
 38 EXPORT_SYMBOL_GPL(key_type_user);
 39 
 40 /*
 41  * This key type is essentially the same as key_type_user, but it does
 42  * not define a .read op. This is suitable for storing username and
 43  * password pairs in the keyring that you do not want to be readable
 44  * from userspace.
 45  */
 46 struct key_type key_type_logon = {
 47         .name                   = "logon",
 48         .instantiate            = user_instantiate,
 49         .update                 = user_update,
 50         .match                  = user_match,
 51         .revoke                 = user_revoke,
 52         .destroy                = user_destroy,
 53         .describe               = user_describe,
 54         .vet_description        = logon_vet_description,
 55 };
 56 EXPORT_SYMBOL_GPL(key_type_logon);
 57 
 58 /*
 59  * instantiate a user defined key
 60  */
 61 int user_instantiate(struct key *key, struct key_preparsed_payload *prep)
 62 {
 63         struct user_key_payload *upayload;
 64         size_t datalen = prep->datalen;
 65         int ret;
 66 
 67         ret = -EINVAL;
 68         if (datalen <= 0 || datalen > 32767 || !prep->data)
 69                 goto error;
 70 
 71         ret = key_payload_reserve(key, datalen);
 72         if (ret < 0)
 73                 goto error;
 74 
 75         ret = -ENOMEM;
 76         upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
 77         if (!upayload)
 78                 goto error;
 79 
 80         /* attach the data */
 81         upayload->datalen = datalen;
 82         memcpy(upayload->data, prep->data, datalen);
 83         rcu_assign_keypointer(key, upayload);
 84         ret = 0;
 85 
 86 error:
 87         return ret;
 88 }
 89 
 90 EXPORT_SYMBOL_GPL(user_instantiate);
 91 
 92 /*
 93  * update a user defined key
 94  * - the key's semaphore is write-locked
 95  */
 96 int user_update(struct key *key, struct key_preparsed_payload *prep)
 97 {
 98         struct user_key_payload *upayload, *zap;
 99         size_t datalen = prep->datalen;
100         int ret;
101 
102         ret = -EINVAL;
103         if (datalen <= 0 || datalen > 32767 || !prep->data)
104                 goto error;
105 
106         /* construct a replacement payload */
107         ret = -ENOMEM;
108         upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
109         if (!upayload)
110                 goto error;
111 
112         upayload->datalen = datalen;
113         memcpy(upayload->data, prep->data, datalen);
114 
115         /* check the quota and attach the new data */
116         zap = upayload;
117 
118         ret = key_payload_reserve(key, datalen);
119 
120         if (ret == 0) {
121                 /* attach the new data, displacing the old */
122                 zap = key->payload.data;
123                 rcu_assign_keypointer(key, upayload);
124                 key->expiry = 0;
125         }
126 
127         if (zap)
128                 kfree_rcu(zap, rcu);
129 
130 error:
131         return ret;
132 }
133 
134 EXPORT_SYMBOL_GPL(user_update);
135 
136 /*
137  * match users on their name
138  */
139 int user_match(const struct key *key, const void *description)
140 {
141         return strcmp(key->description, description) == 0;
142 }
143 
144 EXPORT_SYMBOL_GPL(user_match);
145 
146 /*
147  * dispose of the links from a revoked keyring
148  * - called with the key sem write-locked
149  */
150 void user_revoke(struct key *key)
151 {
152         struct user_key_payload *upayload = key->payload.data;
153 
154         /* clear the quota */
155         key_payload_reserve(key, 0);
156 
157         if (upayload) {
158                 rcu_assign_keypointer(key, NULL);
159                 kfree_rcu(upayload, rcu);
160         }
161 }
162 
163 EXPORT_SYMBOL(user_revoke);
164 
165 /*
166  * dispose of the data dangling from the corpse of a user key
167  */
168 void user_destroy(struct key *key)
169 {
170         struct user_key_payload *upayload = key->payload.data;
171 
172         kfree(upayload);
173 }
174 
175 EXPORT_SYMBOL_GPL(user_destroy);
176 
177 /*
178  * describe the user key
179  */
180 void user_describe(const struct key *key, struct seq_file *m)
181 {
182         seq_puts(m, key->description);
183         if (key_is_instantiated(key))
184                 seq_printf(m, ": %u", key->datalen);
185 }
186 
187 EXPORT_SYMBOL_GPL(user_describe);
188 
189 /*
190  * read the key data
191  * - the key's semaphore is read-locked
192  */
193 long user_read(const struct key *key, char __user *buffer, size_t buflen)
194 {
195         struct user_key_payload *upayload;
196         long ret;
197 
198         upayload = rcu_dereference_key(key);
199         ret = upayload->datalen;
200 
201         /* we can return the data as is */
202         if (buffer && buflen > 0) {
203                 if (buflen > upayload->datalen)
204                         buflen = upayload->datalen;
205 
206                 if (copy_to_user(buffer, upayload->data, buflen) != 0)
207                         ret = -EFAULT;
208         }
209 
210         return ret;
211 }
212 
213 EXPORT_SYMBOL_GPL(user_read);
214 
215 /* Vet the description for a "logon" key */
216 static int logon_vet_description(const char *desc)
217 {
218         char *p;
219 
220         /* require a "qualified" description string */
221         p = strchr(desc, ':');
222         if (!p)
223                 return -EINVAL;
224 
225         /* also reject description with ':' as first char */
226         if (p == desc)
227                 return -EINVAL;
228 
229         return 0;
230 }
231 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp