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authorPaul Moore <pmoore@redhat.com>2014-01-28 14:44:16 -0500
committerPaul Moore <pmoore@redhat.com>2014-02-05 10:39:48 -0500
commit825e587af2e90e9b953849f3347a01d8f383d577 (patch)
treee48942a05882da47544e179c6a0c920e00137a6a /security/integrity/ima/ima_template_lib.c
parent8ed814602876bec9bad2649ca17f34b499357a1c (diff)
parentd8ec26d7f8287f5788a494f56e8814210f0e64be (diff)
Merge tag 'v3.13' into stable-3.14
Linux 3.13 Conflicts: security/selinux/hooks.c Trivial merge issue in selinux_inet_conn_request() likely due to me including patches that I sent to the stable folks in my next tree resulting in the patch hitting twice (I think). Thankfully it was an easy fix this time, but regardless, lesson learned, I will not do that again.
Diffstat (limited to 'security/integrity/ima/ima_template_lib.c')
-rw-r--r--security/integrity/ima/ima_template_lib.c351
1 files changed, 351 insertions, 0 deletions
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
new file mode 100644
index 000000000000..c38adcc910fb
--- /dev/null
+++ b/security/integrity/ima/ima_template_lib.c
@@ -0,0 +1,351 @@
1/*
2 * Copyright (C) 2013 Politecnico di Torino, Italy
3 * TORSEC group -- http://security.polito.it
4 *
5 * Author: Roberto Sassu <roberto.sassu@polito.it>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation, version 2 of the
10 * License.
11 *
12 * File: ima_template_lib.c
13 * Library of supported template fields.
14 */
15#include <crypto/hash_info.h>
16
17#include "ima_template_lib.h"
18
19static bool ima_template_hash_algo_allowed(u8 algo)
20{
21 if (algo == HASH_ALGO_SHA1 || algo == HASH_ALGO_MD5)
22 return true;
23
24 return false;
25}
26
27enum data_formats {
28 DATA_FMT_DIGEST = 0,
29 DATA_FMT_DIGEST_WITH_ALGO,
30 DATA_FMT_EVENT_NAME,
31 DATA_FMT_STRING,
32 DATA_FMT_HEX
33};
34
35static int ima_write_template_field_data(const void *data, const u32 datalen,
36 enum data_formats datafmt,
37 struct ima_field_data *field_data)
38{
39 u8 *buf, *buf_ptr;
40 u32 buflen;
41
42 switch (datafmt) {
43 case DATA_FMT_EVENT_NAME:
44 buflen = IMA_EVENT_NAME_LEN_MAX + 1;
45 break;
46 case DATA_FMT_STRING:
47 buflen = datalen + 1;
48 break;
49 default:
50 buflen = datalen;
51 }
52
53 buf = kzalloc(buflen, GFP_KERNEL);
54 if (!buf)
55 return -ENOMEM;
56
57 memcpy(buf, data, datalen);
58
59 /*
60 * Replace all space characters with underscore for event names and
61 * strings. This avoid that, during the parsing of a measurements list,
62 * filenames with spaces or that end with the suffix ' (deleted)' are
63 * split into multiple template fields (the space is the delimitator
64 * character for measurements lists in ASCII format).
65 */
66 if (datafmt == DATA_FMT_EVENT_NAME || datafmt == DATA_FMT_STRING) {
67 for (buf_ptr = buf; buf_ptr - buf < datalen; buf_ptr++)
68 if (*buf_ptr == ' ')
69 *buf_ptr = '_';
70 }
71
72 field_data->data = buf;
73 field_data->len = buflen;
74 return 0;
75}
76
77static void ima_show_template_data_ascii(struct seq_file *m,
78 enum ima_show_type show,
79 enum data_formats datafmt,
80 struct ima_field_data *field_data)
81{
82 u8 *buf_ptr = field_data->data, buflen = field_data->len;
83
84 switch (datafmt) {
85 case DATA_FMT_DIGEST_WITH_ALGO:
86 buf_ptr = strnchr(field_data->data, buflen, ':');
87 if (buf_ptr != field_data->data)
88 seq_printf(m, "%s", field_data->data);
89
90 /* skip ':' and '\0' */
91 buf_ptr += 2;
92 buflen -= buf_ptr - field_data->data;
93 case DATA_FMT_DIGEST:
94 case DATA_FMT_HEX:
95 if (!buflen)
96 break;
97 ima_print_digest(m, buf_ptr, buflen);
98 break;
99 case DATA_FMT_STRING:
100 seq_printf(m, "%s", buf_ptr);
101 break;
102 default:
103 break;
104 }
105}
106
107static void ima_show_template_data_binary(struct seq_file *m,
108 enum ima_show_type show,
109 enum data_formats datafmt,
110 struct ima_field_data *field_data)
111{
112 if (show != IMA_SHOW_BINARY_NO_FIELD_LEN)
113 ima_putc(m, &field_data->len, sizeof(u32));
114
115 if (!field_data->len)
116 return;
117
118 ima_putc(m, field_data->data, field_data->len);
119}
120
121static void ima_show_template_field_data(struct seq_file *m,
122 enum ima_show_type show,
123 enum data_formats datafmt,
124 struct ima_field_data *field_data)
125{
126 switch (show) {
127 case IMA_SHOW_ASCII:
128 ima_show_template_data_ascii(m, show, datafmt, field_data);
129 break;
130 case IMA_SHOW_BINARY:
131 case IMA_SHOW_BINARY_NO_FIELD_LEN:
132 ima_show_template_data_binary(m, show, datafmt, field_data);
133 break;
134 default:
135 break;
136 }
137}
138
139void ima_show_template_digest(struct seq_file *m, enum ima_show_type show,
140 struct ima_field_data *field_data)
141{
142 ima_show_template_field_data(m, show, DATA_FMT_DIGEST, field_data);
143}
144
145void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show,
146 struct ima_field_data *field_data)
147{
148 ima_show_template_field_data(m, show, DATA_FMT_DIGEST_WITH_ALGO,
149 field_data);
150}
151
152void ima_show_template_string(struct seq_file *m, enum ima_show_type show,
153 struct ima_field_data *field_data)
154{
155 ima_show_template_field_data(m, show, DATA_FMT_STRING, field_data);
156}
157
158void ima_show_template_sig(struct seq_file *m, enum ima_show_type show,
159 struct ima_field_data *field_data)
160{
161 ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data);
162}
163
164static int ima_eventdigest_init_common(u8 *digest, u32 digestsize, u8 hash_algo,
165 struct ima_field_data *field_data,
166 bool size_limit)
167{
168 /*
169 * digest formats:
170 * - DATA_FMT_DIGEST: digest
171 * - DATA_FMT_DIGEST_WITH_ALGO: [<hash algo>] + ':' + '\0' + digest,
172 * where <hash algo> is provided if the hash algoritm is not
173 * SHA1 or MD5
174 */
175 u8 buffer[CRYPTO_MAX_ALG_NAME + 2 + IMA_MAX_DIGEST_SIZE] = { 0 };
176 enum data_formats fmt = DATA_FMT_DIGEST;
177 u32 offset = 0;
178
179 if (!size_limit) {
180 fmt = DATA_FMT_DIGEST_WITH_ALGO;
181 if (hash_algo < HASH_ALGO__LAST)
182 offset += snprintf(buffer, CRYPTO_MAX_ALG_NAME + 1,
183 "%s", hash_algo_name[hash_algo]);
184 buffer[offset] = ':';
185 offset += 2;
186 }
187
188 if (digest)
189 memcpy(buffer + offset, digest, digestsize);
190 else
191 /*
192 * If digest is NULL, the event being recorded is a violation.
193 * Make room for the digest by increasing the offset of
194 * IMA_DIGEST_SIZE.
195 */
196 offset += IMA_DIGEST_SIZE;
197
198 return ima_write_template_field_data(buffer, offset + digestsize,
199 fmt, field_data);
200}
201
202/*
203 * This function writes the digest of an event (with size limit).
204 */
205int ima_eventdigest_init(struct integrity_iint_cache *iint, struct file *file,
206 const unsigned char *filename,
207 struct evm_ima_xattr_data *xattr_value, int xattr_len,
208 struct ima_field_data *field_data)
209{
210 struct {
211 struct ima_digest_data hdr;
212 char digest[IMA_MAX_DIGEST_SIZE];
213 } hash;
214 u8 *cur_digest = NULL;
215 u32 cur_digestsize = 0;
216 struct inode *inode;
217 int result;
218
219 memset(&hash, 0, sizeof(hash));
220
221 if (!iint) /* recording a violation. */
222 goto out;
223
224 if (ima_template_hash_algo_allowed(iint->ima_hash->algo)) {
225 cur_digest = iint->ima_hash->digest;
226 cur_digestsize = iint->ima_hash->length;
227 goto out;
228 }
229
230 if (!file) /* missing info to re-calculate the digest */
231 return -EINVAL;
232
233 inode = file_inode(file);
234 hash.hdr.algo = ima_template_hash_algo_allowed(ima_hash_algo) ?
235 ima_hash_algo : HASH_ALGO_SHA1;
236 result = ima_calc_file_hash(file, &hash.hdr);
237 if (result) {
238 integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
239 filename, "collect_data",
240 "failed", result, 0);
241 return result;
242 }
243 cur_digest = hash.hdr.digest;
244 cur_digestsize = hash.hdr.length;
245out:
246 return ima_eventdigest_init_common(cur_digest, cur_digestsize, -1,
247 field_data, true);
248}
249
250/*
251 * This function writes the digest of an event (without size limit).
252 */
253int ima_eventdigest_ng_init(struct integrity_iint_cache *iint,
254 struct file *file, const unsigned char *filename,
255 struct evm_ima_xattr_data *xattr_value,
256 int xattr_len, struct ima_field_data *field_data)
257{
258 u8 *cur_digest = NULL, hash_algo = HASH_ALGO__LAST;
259 u32 cur_digestsize = 0;
260
261 /* If iint is NULL, we are recording a violation. */
262 if (!iint)
263 goto out;
264
265 cur_digest = iint->ima_hash->digest;
266 cur_digestsize = iint->ima_hash->length;
267
268 hash_algo = iint->ima_hash->algo;
269out:
270 return ima_eventdigest_init_common(cur_digest, cur_digestsize,
271 hash_algo, field_data, false);
272}
273
274static int ima_eventname_init_common(struct integrity_iint_cache *iint,
275 struct file *file,
276 const unsigned char *filename,
277 struct ima_field_data *field_data,
278 bool size_limit)
279{
280 const char *cur_filename = NULL;
281 u32 cur_filename_len = 0;
282 enum data_formats fmt = size_limit ?
283 DATA_FMT_EVENT_NAME : DATA_FMT_STRING;
284
285 BUG_ON(filename == NULL && file == NULL);
286
287 if (filename) {
288 cur_filename = filename;
289 cur_filename_len = strlen(filename);
290
291 if (!size_limit || cur_filename_len <= IMA_EVENT_NAME_LEN_MAX)
292 goto out;
293 }
294
295 if (file) {
296 cur_filename = file->f_dentry->d_name.name;
297 cur_filename_len = strlen(cur_filename);
298 } else
299 /*
300 * Truncate filename if the latter is too long and
301 * the file descriptor is not available.
302 */
303 cur_filename_len = IMA_EVENT_NAME_LEN_MAX;
304out:
305 return ima_write_template_field_data(cur_filename, cur_filename_len,
306 fmt, field_data);
307}
308
309/*
310 * This function writes the name of an event (with size limit).
311 */
312int ima_eventname_init(struct integrity_iint_cache *iint, struct file *file,
313 const unsigned char *filename,
314 struct evm_ima_xattr_data *xattr_value, int xattr_len,
315 struct ima_field_data *field_data)
316{
317 return ima_eventname_init_common(iint, file, filename,
318 field_data, true);
319}
320
321/*
322 * This function writes the name of an event (without size limit).
323 */
324int ima_eventname_ng_init(struct integrity_iint_cache *iint, struct file *file,
325 const unsigned char *filename,
326 struct evm_ima_xattr_data *xattr_value, int xattr_len,
327 struct ima_field_data *field_data)
328{
329 return ima_eventname_init_common(iint, file, filename,
330 field_data, false);
331}
332
333/*
334 * ima_eventsig_init - include the file signature as part of the template data
335 */
336int ima_eventsig_init(struct integrity_iint_cache *iint, struct file *file,
337 const unsigned char *filename,
338 struct evm_ima_xattr_data *xattr_value, int xattr_len,
339 struct ima_field_data *field_data)
340{
341 enum data_formats fmt = DATA_FMT_HEX;
342 int rc = 0;
343
344 if ((!xattr_value) || (xattr_value->type != EVM_IMA_XATTR_DIGSIG))
345 goto out;
346
347 rc = ima_write_template_field_data(xattr_value, xattr_len, fmt,
348 field_data);
349out:
350 return rc;
351}