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.
15 #include <crypto/hash_info.h>
17 #include "ima_template_lib.h"
19 static bool ima_template_hash_algo_allowed(u8 algo)
21 if (algo == HASH_ALGO_SHA1 || algo == HASH_ALGO_MD5)
29 DATA_FMT_DIGEST_WITH_ALGO,
34 static int ima_write_template_field_data(const void *data, const u32 datalen,
35 enum data_formats datafmt,
36 struct ima_field_data *field_data)
41 if (datafmt == DATA_FMT_STRING)
44 buf = kzalloc(buflen, GFP_KERNEL);
48 memcpy(buf, data, datalen);
51 * Replace all space characters with underscore for event names and
52 * strings. This avoid that, during the parsing of a measurements list,
53 * filenames with spaces or that end with the suffix ' (deleted)' are
54 * split into multiple template fields (the space is the delimitator
55 * character for measurements lists in ASCII format).
57 if (datafmt == DATA_FMT_STRING) {
58 for (buf_ptr = buf; buf_ptr - buf < datalen; buf_ptr++)
63 field_data->data = buf;
64 field_data->len = buflen;
68 static void ima_show_template_data_ascii(struct seq_file *m,
69 enum ima_show_type show,
70 enum data_formats datafmt,
71 struct ima_field_data *field_data)
73 u8 *buf_ptr = field_data->data;
74 u32 buflen = field_data->len;
77 case DATA_FMT_DIGEST_WITH_ALGO:
78 buf_ptr = strnchr(field_data->data, buflen, ':');
79 if (buf_ptr != field_data->data)
80 seq_printf(m, "%s", field_data->data);
82 /* skip ':' and '\0' */
84 buflen -= buf_ptr - field_data->data;
89 ima_print_digest(m, buf_ptr, buflen);
92 seq_printf(m, "%s", buf_ptr);
99 static void ima_show_template_data_binary(struct seq_file *m,
100 enum ima_show_type show,
101 enum data_formats datafmt,
102 struct ima_field_data *field_data)
104 u32 len = (show == IMA_SHOW_BINARY_OLD_STRING_FMT) ?
105 strlen(field_data->data) : field_data->len;
107 if (show != IMA_SHOW_BINARY_NO_FIELD_LEN)
108 ima_putc(m, &len, sizeof(len));
113 ima_putc(m, field_data->data, len);
116 static void ima_show_template_field_data(struct seq_file *m,
117 enum ima_show_type show,
118 enum data_formats datafmt,
119 struct ima_field_data *field_data)
123 ima_show_template_data_ascii(m, show, datafmt, field_data);
125 case IMA_SHOW_BINARY:
126 case IMA_SHOW_BINARY_NO_FIELD_LEN:
127 case IMA_SHOW_BINARY_OLD_STRING_FMT:
128 ima_show_template_data_binary(m, show, datafmt, field_data);
135 void ima_show_template_digest(struct seq_file *m, enum ima_show_type show,
136 struct ima_field_data *field_data)
138 ima_show_template_field_data(m, show, DATA_FMT_DIGEST, field_data);
141 void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show,
142 struct ima_field_data *field_data)
144 ima_show_template_field_data(m, show, DATA_FMT_DIGEST_WITH_ALGO,
148 void ima_show_template_string(struct seq_file *m, enum ima_show_type show,
149 struct ima_field_data *field_data)
151 ima_show_template_field_data(m, show, DATA_FMT_STRING, field_data);
154 void ima_show_template_sig(struct seq_file *m, enum ima_show_type show,
155 struct ima_field_data *field_data)
157 ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data);
160 static int ima_eventdigest_init_common(u8 *digest, u32 digestsize, u8 hash_algo,
161 struct ima_field_data *field_data)
165 * - DATA_FMT_DIGEST: digest
166 * - DATA_FMT_DIGEST_WITH_ALGO: [<hash algo>] + ':' + '\0' + digest,
167 * where <hash algo> is provided if the hash algoritm is not
170 u8 buffer[CRYPTO_MAX_ALG_NAME + 2 + IMA_MAX_DIGEST_SIZE] = { 0 };
171 enum data_formats fmt = DATA_FMT_DIGEST;
174 if (hash_algo < HASH_ALGO__LAST) {
175 fmt = DATA_FMT_DIGEST_WITH_ALGO;
176 offset += snprintf(buffer, CRYPTO_MAX_ALG_NAME + 1, "%s",
177 hash_algo_name[hash_algo]);
178 buffer[offset] = ':';
183 memcpy(buffer + offset, digest, digestsize);
186 * If digest is NULL, the event being recorded is a violation.
187 * Make room for the digest by increasing the offset of
190 offset += IMA_DIGEST_SIZE;
192 return ima_write_template_field_data(buffer, offset + digestsize,
197 * This function writes the digest of an event (with size limit).
199 int ima_eventdigest_init(struct integrity_iint_cache *iint, struct file *file,
200 const unsigned char *filename,
201 struct evm_ima_xattr_data *xattr_value, int xattr_len,
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 (!iint) /* recording a violation. */
218 if (ima_template_hash_algo_allowed(iint->ima_hash->algo)) {
219 cur_digest = iint->ima_hash->digest;
220 cur_digestsize = iint->ima_hash->length;
224 if (!file) /* missing info to re-calculate the digest */
227 inode = file_inode(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(file, &hash.hdr);
232 integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
233 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 integrity_iint_cache *iint,
248 struct file *file, const unsigned char *filename,
249 struct evm_ima_xattr_data *xattr_value,
250 int xattr_len, struct ima_field_data *field_data)
252 u8 *cur_digest = NULL, hash_algo = HASH_ALGO_SHA1;
253 u32 cur_digestsize = 0;
255 /* If iint is NULL, we are recording a violation. */
259 cur_digest = iint->ima_hash->digest;
260 cur_digestsize = iint->ima_hash->length;
262 hash_algo = iint->ima_hash->algo;
264 return ima_eventdigest_init_common(cur_digest, cur_digestsize,
265 hash_algo, field_data);
268 static int ima_eventname_init_common(struct integrity_iint_cache *iint,
270 const unsigned char *filename,
271 struct ima_field_data *field_data,
274 const char *cur_filename = NULL;
275 u32 cur_filename_len = 0;
277 BUG_ON(filename == NULL && file == NULL);
280 cur_filename = filename;
281 cur_filename_len = strlen(filename);
283 if (!size_limit || cur_filename_len <= IMA_EVENT_NAME_LEN_MAX)
288 cur_filename = file->f_path.dentry->d_name.name;
289 cur_filename_len = strlen(cur_filename);
292 * Truncate filename if the latter is too long and
293 * the file descriptor is not available.
295 cur_filename_len = IMA_EVENT_NAME_LEN_MAX;
297 return ima_write_template_field_data(cur_filename, cur_filename_len,
298 DATA_FMT_STRING, field_data);
302 * This function writes the name of an event (with size limit).
304 int ima_eventname_init(struct integrity_iint_cache *iint, struct file *file,
305 const unsigned char *filename,
306 struct evm_ima_xattr_data *xattr_value, int xattr_len,
307 struct ima_field_data *field_data)
309 return ima_eventname_init_common(iint, file, filename,
314 * This function writes the name of an event (without size limit).
316 int ima_eventname_ng_init(struct integrity_iint_cache *iint, struct file *file,
317 const unsigned char *filename,
318 struct evm_ima_xattr_data *xattr_value, int xattr_len,
319 struct ima_field_data *field_data)
321 return ima_eventname_init_common(iint, file, filename,
326 * ima_eventsig_init - include the file signature as part of the template data
328 int ima_eventsig_init(struct integrity_iint_cache *iint, struct file *file,
329 const unsigned char *filename,
330 struct evm_ima_xattr_data *xattr_value, int xattr_len,
331 struct ima_field_data *field_data)
333 enum data_formats fmt = DATA_FMT_HEX;
336 if ((!xattr_value) || (xattr_value->type != EVM_IMA_XATTR_DIGSIG))
339 rc = ima_write_template_field_data(xattr_value, xattr_len, fmt,