1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2013 Politecnico di Torino, Italy
4 * TORSEC group -- http://security.polito.it
6 * Author: Roberto Sassu <roberto.sassu@polito.it>
8 * File: ima_template_lib.c
9 * Library of supported template fields.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include "ima_template_lib.h"
16 static bool ima_template_hash_algo_allowed(u8 algo)
18 if (algo == HASH_ALGO_SHA1 || algo == HASH_ALGO_MD5)
26 DATA_FMT_DIGEST_WITH_ALGO,
31 static int ima_write_template_field_data(const void *data, const u32 datalen,
32 enum data_formats datafmt,
33 struct ima_field_data *field_data)
38 if (datafmt == DATA_FMT_STRING)
41 buf = kzalloc(buflen, GFP_KERNEL);
45 memcpy(buf, data, datalen);
48 * Replace all space characters with underscore for event names and
49 * strings. This avoid that, during the parsing of a measurements list,
50 * filenames with spaces or that end with the suffix ' (deleted)' are
51 * split into multiple template fields (the space is the delimitator
52 * character for measurements lists in ASCII format).
54 if (datafmt == DATA_FMT_STRING) {
55 for (buf_ptr = buf; buf_ptr - buf < datalen; buf_ptr++)
60 field_data->data = buf;
61 field_data->len = buflen;
65 static void ima_show_template_data_ascii(struct seq_file *m,
66 enum ima_show_type show,
67 enum data_formats datafmt,
68 struct ima_field_data *field_data)
70 u8 *buf_ptr = field_data->data;
71 u32 buflen = field_data->len;
74 case DATA_FMT_DIGEST_WITH_ALGO:
75 buf_ptr = strnchr(field_data->data, buflen, ':');
76 if (buf_ptr != field_data->data)
77 seq_printf(m, "%s", field_data->data);
79 /* skip ':' and '\0' */
81 buflen -= buf_ptr - field_data->data;
87 ima_print_digest(m, buf_ptr, buflen);
90 seq_printf(m, "%s", buf_ptr);
97 static void ima_show_template_data_binary(struct seq_file *m,
98 enum ima_show_type show,
99 enum data_formats datafmt,
100 struct ima_field_data *field_data)
102 u32 len = (show == IMA_SHOW_BINARY_OLD_STRING_FMT) ?
103 strlen(field_data->data) : field_data->len;
105 if (show != IMA_SHOW_BINARY_NO_FIELD_LEN) {
106 u32 field_len = !ima_canonical_fmt ? len : cpu_to_le32(len);
108 ima_putc(m, &field_len, sizeof(field_len));
114 ima_putc(m, field_data->data, len);
117 static void ima_show_template_field_data(struct seq_file *m,
118 enum ima_show_type show,
119 enum data_formats datafmt,
120 struct ima_field_data *field_data)
124 ima_show_template_data_ascii(m, show, datafmt, field_data);
126 case IMA_SHOW_BINARY:
127 case IMA_SHOW_BINARY_NO_FIELD_LEN:
128 case IMA_SHOW_BINARY_OLD_STRING_FMT:
129 ima_show_template_data_binary(m, show, datafmt, field_data);
136 void ima_show_template_digest(struct seq_file *m, enum ima_show_type show,
137 struct ima_field_data *field_data)
139 ima_show_template_field_data(m, show, DATA_FMT_DIGEST, field_data);
142 void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show,
143 struct ima_field_data *field_data)
145 ima_show_template_field_data(m, show, DATA_FMT_DIGEST_WITH_ALGO,
149 void ima_show_template_string(struct seq_file *m, enum ima_show_type show,
150 struct ima_field_data *field_data)
152 ima_show_template_field_data(m, show, DATA_FMT_STRING, field_data);
155 void ima_show_template_sig(struct seq_file *m, enum ima_show_type show,
156 struct ima_field_data *field_data)
158 ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data);
161 void ima_show_template_buf(struct seq_file *m, enum ima_show_type show,
162 struct ima_field_data *field_data)
164 ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data);
168 * ima_parse_buf() - Parses lengths and data from an input buffer
169 * @bufstartp: Buffer start address.
170 * @bufendp: Buffer end address.
171 * @bufcurp: Pointer to remaining (non-parsed) data.
172 * @maxfields: Length of fields array.
173 * @fields: Array containing lengths and pointers of parsed data.
174 * @curfields: Number of array items containing parsed data.
175 * @len_mask: Bitmap (if bit is set, data length should not be parsed).
176 * @enforce_mask: Check if curfields == maxfields and/or bufcurp == bufendp.
177 * @bufname: String identifier of the input buffer.
179 * Return: 0 on success, -EINVAL on error.
181 int ima_parse_buf(void *bufstartp, void *bufendp, void **bufcurp,
182 int maxfields, struct ima_field_data *fields, int *curfields,
183 unsigned long *len_mask, int enforce_mask, char *bufname)
185 void *bufp = bufstartp;
188 for (i = 0; i < maxfields; i++) {
189 if (len_mask == NULL || !test_bit(i, len_mask)) {
190 if (bufp > (bufendp - sizeof(u32)))
193 fields[i].len = *(u32 *)bufp;
194 if (ima_canonical_fmt)
195 fields[i].len = le32_to_cpu(fields[i].len);
200 if (bufp > (bufendp - fields[i].len))
203 fields[i].data = bufp;
204 bufp += fields[i].len;
207 if ((enforce_mask & ENFORCE_FIELDS) && i != maxfields) {
208 pr_err("%s: nr of fields mismatch: expected: %d, current: %d\n",
209 bufname, maxfields, i);
213 if ((enforce_mask & ENFORCE_BUFEND) && bufp != bufendp) {
214 pr_err("%s: buf end mismatch: expected: %p, current: %p\n",
215 bufname, bufendp, bufp);
228 static int ima_eventdigest_init_common(const u8 *digest, u32 digestsize,
230 struct ima_field_data *field_data)
234 * - DATA_FMT_DIGEST: digest
235 * - DATA_FMT_DIGEST_WITH_ALGO: [<hash algo>] + ':' + '\0' + digest,
236 * where <hash algo> is provided if the hash algoritm is not
239 u8 buffer[CRYPTO_MAX_ALG_NAME + 2 + IMA_MAX_DIGEST_SIZE] = { 0 };
240 enum data_formats fmt = DATA_FMT_DIGEST;
243 if (hash_algo < HASH_ALGO__LAST) {
244 fmt = DATA_FMT_DIGEST_WITH_ALGO;
245 offset += snprintf(buffer, CRYPTO_MAX_ALG_NAME + 1, "%s",
246 hash_algo_name[hash_algo]);
247 buffer[offset] = ':';
252 memcpy(buffer + offset, digest, digestsize);
255 * If digest is NULL, the event being recorded is a violation.
256 * Make room for the digest by increasing the offset of
259 offset += IMA_DIGEST_SIZE;
261 return ima_write_template_field_data(buffer, offset + digestsize,
266 * This function writes the digest of an event (with size limit).
268 int ima_eventdigest_init(struct ima_event_data *event_data,
269 struct ima_field_data *field_data)
272 struct ima_digest_data hdr;
273 char digest[IMA_MAX_DIGEST_SIZE];
275 u8 *cur_digest = NULL;
276 u32 cur_digestsize = 0;
280 memset(&hash, 0, sizeof(hash));
282 if (event_data->violation) /* recording a violation. */
285 if (ima_template_hash_algo_allowed(event_data->iint->ima_hash->algo)) {
286 cur_digest = event_data->iint->ima_hash->digest;
287 cur_digestsize = event_data->iint->ima_hash->length;
291 if (!event_data->file) /* missing info to re-calculate the digest */
294 inode = file_inode(event_data->file);
295 hash.hdr.algo = ima_template_hash_algo_allowed(ima_hash_algo) ?
296 ima_hash_algo : HASH_ALGO_SHA1;
297 result = ima_calc_file_hash(event_data->file, &hash.hdr);
299 integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
300 event_data->filename, "collect_data",
301 "failed", result, 0);
304 cur_digest = hash.hdr.digest;
305 cur_digestsize = hash.hdr.length;
307 return ima_eventdigest_init_common(cur_digest, cur_digestsize,
308 HASH_ALGO__LAST, field_data);
312 * This function writes the digest of an event (without size limit).
314 int ima_eventdigest_ng_init(struct ima_event_data *event_data,
315 struct ima_field_data *field_data)
317 u8 *cur_digest = NULL, hash_algo = HASH_ALGO_SHA1;
318 u32 cur_digestsize = 0;
320 if (event_data->violation) /* recording a violation. */
323 cur_digest = event_data->iint->ima_hash->digest;
324 cur_digestsize = event_data->iint->ima_hash->length;
326 hash_algo = event_data->iint->ima_hash->algo;
328 return ima_eventdigest_init_common(cur_digest, cur_digestsize,
329 hash_algo, field_data);
333 * This function writes the digest of the file which is expected to match the
334 * digest contained in the file's appended signature.
336 int ima_eventdigest_modsig_init(struct ima_event_data *event_data,
337 struct ima_field_data *field_data)
339 enum hash_algo hash_algo;
340 const u8 *cur_digest;
343 if (!event_data->modsig)
346 if (event_data->violation) {
347 /* Recording a violation. */
348 hash_algo = HASH_ALGO_SHA1;
354 rc = ima_get_modsig_digest(event_data->modsig, &hash_algo,
355 &cur_digest, &cur_digestsize);
358 else if (hash_algo == HASH_ALGO__LAST || cur_digestsize == 0)
359 /* There was some error collecting the digest. */
363 return ima_eventdigest_init_common(cur_digest, cur_digestsize,
364 hash_algo, field_data);
367 static int ima_eventname_init_common(struct ima_event_data *event_data,
368 struct ima_field_data *field_data,
371 const char *cur_filename = NULL;
372 u32 cur_filename_len = 0;
374 BUG_ON(event_data->filename == NULL && event_data->file == NULL);
376 if (event_data->filename) {
377 cur_filename = event_data->filename;
378 cur_filename_len = strlen(event_data->filename);
380 if (!size_limit || cur_filename_len <= IMA_EVENT_NAME_LEN_MAX)
384 if (event_data->file) {
385 cur_filename = event_data->file->f_path.dentry->d_name.name;
386 cur_filename_len = strlen(cur_filename);
389 * Truncate filename if the latter is too long and
390 * the file descriptor is not available.
392 cur_filename_len = IMA_EVENT_NAME_LEN_MAX;
394 return ima_write_template_field_data(cur_filename, cur_filename_len,
395 DATA_FMT_STRING, field_data);
399 * This function writes the name of an event (with size limit).
401 int ima_eventname_init(struct ima_event_data *event_data,
402 struct ima_field_data *field_data)
404 return ima_eventname_init_common(event_data, field_data, true);
408 * This function writes the name of an event (without size limit).
410 int ima_eventname_ng_init(struct ima_event_data *event_data,
411 struct ima_field_data *field_data)
413 return ima_eventname_init_common(event_data, field_data, false);
417 * ima_eventsig_init - include the file signature as part of the template data
419 int ima_eventsig_init(struct ima_event_data *event_data,
420 struct ima_field_data *field_data)
422 struct evm_ima_xattr_data *xattr_value = event_data->xattr_value;
424 if ((!xattr_value) || (xattr_value->type != EVM_IMA_XATTR_DIGSIG))
427 return ima_write_template_field_data(xattr_value, event_data->xattr_len,
428 DATA_FMT_HEX, field_data);
432 * ima_eventbuf_init - include the buffer(kexec-cmldine) as part of the
435 int ima_eventbuf_init(struct ima_event_data *event_data,
436 struct ima_field_data *field_data)
438 if ((!event_data->buf) || (event_data->buf_len == 0))
441 return ima_write_template_field_data(event_data->buf,
442 event_data->buf_len, DATA_FMT_HEX,
447 * ima_eventmodsig_init - include the appended file signature as part of the
450 int ima_eventmodsig_init(struct ima_event_data *event_data,
451 struct ima_field_data *field_data)
457 if (!event_data->modsig)
461 * modsig is a runtime structure containing pointers. Get its raw data
464 rc = ima_get_raw_modsig(event_data->modsig, &data, &data_len);
468 return ima_write_template_field_data(data, data_len, DATA_FMT_HEX,