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,
35 static int ima_write_template_field_data(const void *data, const u32 datalen,
36 enum data_formats datafmt,
37 struct ima_field_data *field_data)
43 case DATA_FMT_EVENT_NAME:
44 buflen = IMA_EVENT_NAME_LEN_MAX + 1;
53 buf = kzalloc(buflen, GFP_KERNEL);
57 memcpy(buf, data, datalen);
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).
66 if (datafmt == DATA_FMT_EVENT_NAME || datafmt == DATA_FMT_STRING) {
67 for (buf_ptr = buf; buf_ptr - buf < datalen; buf_ptr++)
72 field_data->data = buf;
73 field_data->len = buflen;
77 static 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)
82 u8 *buf_ptr = field_data->data, buflen = field_data->len;
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);
90 /* skip ':' and '\0' */
92 buflen -= buf_ptr - field_data->data;
97 ima_print_digest(m, buf_ptr, buflen);
100 seq_printf(m, "%s", buf_ptr);
107 static 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)
112 ima_putc(m, &field_data->len, sizeof(u32));
113 if (!field_data->len)
115 ima_putc(m, field_data->data, field_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 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,
166 * - DATA_FMT_DIGEST: digest
167 * - DATA_FMT_DIGEST_WITH_ALGO: [<hash algo>] + ':' + '\0' + digest,
168 * where <hash algo> is provided if the hash algoritm is not
171 u8 buffer[CRYPTO_MAX_ALG_NAME + 2 + IMA_MAX_DIGEST_SIZE] = { 0 };
172 enum data_formats fmt = DATA_FMT_DIGEST;
176 fmt = DATA_FMT_DIGEST_WITH_ALGO;
177 if (hash_algo < HASH_ALGO__LAST)
178 offset += snprintf(buffer, CRYPTO_MAX_ALG_NAME + 1,
179 "%s", 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 integrity_iint_cache *iint, struct file *file,
202 const unsigned char *filename,
203 struct evm_ima_xattr_data *xattr_value, int xattr_len,
204 struct ima_field_data *field_data)
207 struct ima_digest_data hdr;
208 char digest[IMA_MAX_DIGEST_SIZE];
210 u8 *cur_digest = NULL;
211 u32 cur_digestsize = 0;
215 memset(&hash, 0, sizeof(hash));
217 if (!iint) /* recording a violation. */
220 if (ima_template_hash_algo_allowed(iint->ima_hash->algo)) {
221 cur_digest = iint->ima_hash->digest;
222 cur_digestsize = iint->ima_hash->length;
226 if (!file) /* missing info to re-calculate the digest */
229 inode = file_inode(file);
230 hash.hdr.algo = ima_template_hash_algo_allowed(ima_hash_algo) ?
231 ima_hash_algo : HASH_ALGO_SHA1;
232 result = ima_calc_file_hash(file, &hash.hdr);
234 integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
235 filename, "collect_data",
236 "failed", result, 0);
239 cur_digest = hash.hdr.digest;
240 cur_digestsize = hash.hdr.length;
242 return ima_eventdigest_init_common(cur_digest, cur_digestsize, -1,
247 * This function writes the digest of an event (without size limit).
249 int ima_eventdigest_ng_init(struct integrity_iint_cache *iint,
250 struct file *file, const unsigned char *filename,
251 struct evm_ima_xattr_data *xattr_value,
252 int xattr_len, struct ima_field_data *field_data)
254 u8 *cur_digest = NULL, hash_algo = HASH_ALGO__LAST;
255 u32 cur_digestsize = 0;
257 /* If iint is NULL, we are recording a violation. */
261 cur_digest = iint->ima_hash->digest;
262 cur_digestsize = iint->ima_hash->length;
264 hash_algo = iint->ima_hash->algo;
266 return ima_eventdigest_init_common(cur_digest, cur_digestsize,
267 hash_algo, field_data, false);
270 static int ima_eventname_init_common(struct integrity_iint_cache *iint,
272 const unsigned char *filename,
273 struct ima_field_data *field_data,
276 const char *cur_filename = NULL;
277 u32 cur_filename_len = 0;
278 enum data_formats fmt = size_limit ?
279 DATA_FMT_EVENT_NAME : DATA_FMT_STRING;
281 BUG_ON(filename == NULL && file == NULL);
284 cur_filename = filename;
285 cur_filename_len = strlen(filename);
287 if (!size_limit || cur_filename_len <= IMA_EVENT_NAME_LEN_MAX)
292 cur_filename = file->f_dentry->d_name.name;
293 cur_filename_len = strlen(cur_filename);
296 * Truncate filename if the latter is too long and
297 * the file descriptor is not available.
299 cur_filename_len = IMA_EVENT_NAME_LEN_MAX;
301 return ima_write_template_field_data(cur_filename, cur_filename_len,
306 * This function writes the name of an event (with size limit).
308 int ima_eventname_init(struct integrity_iint_cache *iint, struct file *file,
309 const unsigned char *filename,
310 struct evm_ima_xattr_data *xattr_value, int xattr_len,
311 struct ima_field_data *field_data)
313 return ima_eventname_init_common(iint, file, filename,
318 * This function writes the name of an event (without size limit).
320 int ima_eventname_ng_init(struct integrity_iint_cache *iint, struct file *file,
321 const unsigned char *filename,
322 struct evm_ima_xattr_data *xattr_value, int xattr_len,
323 struct ima_field_data *field_data)
325 return ima_eventname_init_common(iint, file, filename,
330 * ima_eventsig_init - include the file signature as part of the template data
332 int ima_eventsig_init(struct integrity_iint_cache *iint, struct file *file,
333 const unsigned char *filename,
334 struct evm_ima_xattr_data *xattr_value, int xattr_len,
335 struct ima_field_data *field_data)
337 enum data_formats fmt = DATA_FMT_HEX;
340 if ((!xattr_value) || (xattr_value->type != EVM_IMA_XATTR_DIGSIG))
343 rc = ima_write_template_field_data(xattr_value, xattr_len, fmt,