2 * Copyright (C) 2013 Politecnico di Torino, Italy
3 * TORSEC group -- http://security.polito.it
5 * Author: Roberto Sassu <roberto.sassu@polito.it>
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
12 * File: ima_template_lib.c
13 * Library of supported template fields.
16 #include "ima_template_lib.h"
18 static bool ima_template_hash_algo_allowed(u8 algo)
20 if (algo == HASH_ALGO_SHA1 || algo == HASH_ALGO_MD5)
28 DATA_FMT_DIGEST_WITH_ALGO,
33 static int ima_write_template_field_data(const void *data, const u32 datalen,
34 enum data_formats datafmt,
35 struct ima_field_data *field_data)
40 if (datafmt == DATA_FMT_STRING)
43 buf = kzalloc(buflen, GFP_KERNEL);
47 memcpy(buf, data, datalen);
50 * Replace all space characters with underscore for event names and
51 * strings. This avoid that, during the parsing of a measurements list,
52 * filenames with spaces or that end with the suffix ' (deleted)' are
53 * split into multiple template fields (the space is the delimitator
54 * character for measurements lists in ASCII format).
56 if (datafmt == DATA_FMT_STRING) {
57 for (buf_ptr = buf; buf_ptr - buf < datalen; buf_ptr++)
62 field_data->data = buf;
63 field_data->len = buflen;
67 static void ima_show_template_data_ascii(struct seq_file *m,
68 enum ima_show_type show,
69 enum data_formats datafmt,
70 struct ima_field_data *field_data)
72 u8 *buf_ptr = field_data->data;
73 u32 buflen = field_data->len;
76 case DATA_FMT_DIGEST_WITH_ALGO:
77 buf_ptr = strnchr(field_data->data, buflen, ':');
78 if (buf_ptr != field_data->data)
79 seq_printf(m, "%s", field_data->data);
81 /* skip ':' and '\0' */
83 buflen -= buf_ptr - field_data->data;
88 ima_print_digest(m, buf_ptr, buflen);
91 seq_printf(m, "%s", buf_ptr);
98 static void ima_show_template_data_binary(struct seq_file *m,
99 enum ima_show_type show,
100 enum data_formats datafmt,
101 struct ima_field_data *field_data)
103 u32 len = (show == IMA_SHOW_BINARY_OLD_STRING_FMT) ?
104 strlen(field_data->data) : field_data->len;
106 if (show != IMA_SHOW_BINARY_NO_FIELD_LEN) {
107 u32 field_len = !ima_canonical_fmt ? len : cpu_to_le32(len);
109 ima_putc(m, &field_len, sizeof(field_len));
115 ima_putc(m, field_data->data, len);
118 static void ima_show_template_field_data(struct seq_file *m,
119 enum ima_show_type show,
120 enum data_formats datafmt,
121 struct ima_field_data *field_data)
125 ima_show_template_data_ascii(m, show, datafmt, field_data);
127 case IMA_SHOW_BINARY:
128 case IMA_SHOW_BINARY_NO_FIELD_LEN:
129 case IMA_SHOW_BINARY_OLD_STRING_FMT:
130 ima_show_template_data_binary(m, show, datafmt, field_data);
137 void ima_show_template_digest(struct seq_file *m, enum ima_show_type show,
138 struct ima_field_data *field_data)
140 ima_show_template_field_data(m, show, DATA_FMT_DIGEST, field_data);
143 void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show,
144 struct ima_field_data *field_data)
146 ima_show_template_field_data(m, show, DATA_FMT_DIGEST_WITH_ALGO,
150 void ima_show_template_string(struct seq_file *m, enum ima_show_type show,
151 struct ima_field_data *field_data)
153 ima_show_template_field_data(m, show, DATA_FMT_STRING, field_data);
156 void ima_show_template_sig(struct seq_file *m, enum ima_show_type show,
157 struct ima_field_data *field_data)
159 ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data);
162 static int ima_eventdigest_init_common(u8 *digest, u32 digestsize, u8 hash_algo,
163 struct ima_field_data *field_data)
167 * - DATA_FMT_DIGEST: digest
168 * - DATA_FMT_DIGEST_WITH_ALGO: [<hash algo>] + ':' + '\0' + digest,
169 * where <hash algo> is provided if the hash algoritm is not
172 u8 buffer[CRYPTO_MAX_ALG_NAME + 2 + IMA_MAX_DIGEST_SIZE] = { 0 };
173 enum data_formats fmt = DATA_FMT_DIGEST;
176 if (hash_algo < HASH_ALGO__LAST) {
177 fmt = DATA_FMT_DIGEST_WITH_ALGO;
178 offset += snprintf(buffer, CRYPTO_MAX_ALG_NAME + 1, "%s",
179 hash_algo_name[hash_algo]);
180 buffer[offset] = ':';
185 memcpy(buffer + offset, digest, digestsize);
188 * If digest is NULL, the event being recorded is a violation.
189 * Make room for the digest by increasing the offset of
192 offset += IMA_DIGEST_SIZE;
194 return ima_write_template_field_data(buffer, offset + digestsize,
199 * This function writes the digest of an event (with size limit).
201 int ima_eventdigest_init(struct ima_event_data *event_data,
202 struct ima_field_data *field_data)
205 struct ima_digest_data hdr;
206 char digest[IMA_MAX_DIGEST_SIZE];
208 u8 *cur_digest = NULL;
209 u32 cur_digestsize = 0;
213 memset(&hash, 0, sizeof(hash));
215 if (event_data->violation) /* recording a violation. */
218 if (ima_template_hash_algo_allowed(event_data->iint->ima_hash->algo)) {
219 cur_digest = event_data->iint->ima_hash->digest;
220 cur_digestsize = event_data->iint->ima_hash->length;
224 if (!event_data->file) /* missing info to re-calculate the digest */
227 inode = file_inode(event_data->file);
228 hash.hdr.algo = ima_template_hash_algo_allowed(ima_hash_algo) ?
229 ima_hash_algo : HASH_ALGO_SHA1;
230 result = ima_calc_file_hash(event_data->file, &hash.hdr);
232 integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
233 event_data->filename, "collect_data",
234 "failed", result, 0);
237 cur_digest = hash.hdr.digest;
238 cur_digestsize = hash.hdr.length;
240 return ima_eventdigest_init_common(cur_digest, cur_digestsize,
241 HASH_ALGO__LAST, field_data);
245 * This function writes the digest of an event (without size limit).
247 int ima_eventdigest_ng_init(struct ima_event_data *event_data,
248 struct ima_field_data *field_data)
250 u8 *cur_digest = NULL, hash_algo = HASH_ALGO_SHA1;
251 u32 cur_digestsize = 0;
253 if (event_data->violation) /* recording a violation. */
256 cur_digest = event_data->iint->ima_hash->digest;
257 cur_digestsize = event_data->iint->ima_hash->length;
259 hash_algo = event_data->iint->ima_hash->algo;
261 return ima_eventdigest_init_common(cur_digest, cur_digestsize,
262 hash_algo, field_data);
265 static int ima_eventname_init_common(struct ima_event_data *event_data,
266 struct ima_field_data *field_data,
269 const char *cur_filename = NULL;
270 u32 cur_filename_len = 0;
272 BUG_ON(event_data->filename == NULL && event_data->file == NULL);
274 if (event_data->filename) {
275 cur_filename = event_data->filename;
276 cur_filename_len = strlen(event_data->filename);
278 if (!size_limit || cur_filename_len <= IMA_EVENT_NAME_LEN_MAX)
282 if (event_data->file) {
283 cur_filename = event_data->file->f_path.dentry->d_name.name;
284 cur_filename_len = strlen(cur_filename);
287 * Truncate filename if the latter is too long and
288 * the file descriptor is not available.
290 cur_filename_len = IMA_EVENT_NAME_LEN_MAX;
292 return ima_write_template_field_data(cur_filename, cur_filename_len,
293 DATA_FMT_STRING, field_data);
297 * This function writes the name of an event (with size limit).
299 int ima_eventname_init(struct ima_event_data *event_data,
300 struct ima_field_data *field_data)
302 return ima_eventname_init_common(event_data, field_data, true);
306 * This function writes the name of an event (without size limit).
308 int ima_eventname_ng_init(struct ima_event_data *event_data,
309 struct ima_field_data *field_data)
311 return ima_eventname_init_common(event_data, field_data, false);
315 * ima_eventsig_init - include the file signature as part of the template data
317 int ima_eventsig_init(struct ima_event_data *event_data,
318 struct ima_field_data *field_data)
320 enum data_formats fmt = DATA_FMT_HEX;
321 struct evm_ima_xattr_data *xattr_value = event_data->xattr_value;
322 int xattr_len = event_data->xattr_len;
325 if ((!xattr_value) || (xattr_value->type != EVM_IMA_XATTR_DIGSIG))
328 rc = ima_write_template_field_data(xattr_value, xattr_len, fmt,