[mirror_ubuntu-artful-kernel.git] / security / integrity / ima / ima_template_lib.c

/*
 * Copyright (C) 2013 Politecnico di Torino, Italy
 *                    TORSEC group -- http://security.polito.it
 *
 * Author: Roberto Sassu <roberto.sassu@polito.it>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, version 2 of the
 * License.
 *
 * File: ima_template_lib.c
 *      Library of supported template fields.
 */
#include <crypto/hash_info.h>

#include "ima_template_lib.h"

static bool ima_template_hash_algo_allowed(u8 algo)
{
	if (algo == HASH_ALGO_SHA1 || algo == HASH_ALGO_MD5)
		return true;

	return false;
}

enum data_formats {
	DATA_FMT_DIGEST = 0,
	DATA_FMT_DIGEST_WITH_ALGO,
	DATA_FMT_EVENT_NAME,
	DATA_FMT_STRING,
	DATA_FMT_HEX
};

static int ima_write_template_field_data(const void *data, const u32 datalen,
					 enum data_formats datafmt,
					 struct ima_field_data *field_data)
{
	u8 *buf, *buf_ptr;
	u32 buflen;

	switch (datafmt) {
	case DATA_FMT_EVENT_NAME:
		buflen = IMA_EVENT_NAME_LEN_MAX + 1;
		break;
	case DATA_FMT_STRING:
		buflen = datalen + 1;
		break;
	default:
		buflen = datalen;
	}

	buf = kzalloc(buflen, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	memcpy(buf, data, datalen);

	/*
	 * Replace all space characters with underscore for event names and
	 * strings. This avoid that, during the parsing of a measurements list,
	 * filenames with spaces or that end with the suffix ' (deleted)' are
	 * split into multiple template fields (the space is the delimitator
	 * character for measurements lists in ASCII format).
	 */
	if (datafmt == DATA_FMT_EVENT_NAME || datafmt == DATA_FMT_STRING) {
		for (buf_ptr = buf; buf_ptr - buf < datalen; buf_ptr++)
			if (*buf_ptr == ' ')
				*buf_ptr = '_';
	}

	field_data->data = buf;
	field_data->len = buflen;
	return 0;
}

static void ima_show_template_data_ascii(struct seq_file *m,
					 enum ima_show_type show,
					 enum data_formats datafmt,
					 struct ima_field_data *field_data)
{
	u8 *buf_ptr = field_data->data, buflen = field_data->len;

	switch (datafmt) {
	case DATA_FMT_DIGEST_WITH_ALGO:
		buf_ptr = strnchr(field_data->data, buflen, ':');
		if (buf_ptr != field_data->data)
			seq_printf(m, "%s", field_data->data);

		/* skip ':' and '\0' */
		buf_ptr += 2;
		buflen -= buf_ptr - field_data->data;
	case DATA_FMT_DIGEST:
	case DATA_FMT_HEX:
		if (!buflen)
			break;
		ima_print_digest(m, buf_ptr, buflen);
		break;
	case DATA_FMT_STRING:
		seq_printf(m, "%s", buf_ptr);
		break;
	default:
		break;
	}
}

static void ima_show_template_data_binary(struct seq_file *m,
					  enum ima_show_type show,
					  enum data_formats datafmt,
					  struct ima_field_data *field_data)
{
	ima_putc(m, &field_data->len, sizeof(u32));
	if (!field_data->len)
		return;
	ima_putc(m, field_data->data, field_data->len);
}

static void ima_show_template_field_data(struct seq_file *m,
					 enum ima_show_type show,
					 enum data_formats datafmt,
					 struct ima_field_data *field_data)
{
	switch (show) {
	case IMA_SHOW_ASCII:
		ima_show_template_data_ascii(m, show, datafmt, field_data);
		break;
	case IMA_SHOW_BINARY:
		ima_show_template_data_binary(m, show, datafmt, field_data);
		break;
	default:
		break;
	}
}

void ima_show_template_digest(struct seq_file *m, enum ima_show_type show,
			      struct ima_field_data *field_data)
{
	ima_show_template_field_data(m, show, DATA_FMT_DIGEST, field_data);
}

void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show,
				 struct ima_field_data *field_data)
{
	ima_show_template_field_data(m, show, DATA_FMT_DIGEST_WITH_ALGO,
				     field_data);
}

void ima_show_template_string(struct seq_file *m, enum ima_show_type show,
			      struct ima_field_data *field_data)
{
	ima_show_template_field_data(m, show, DATA_FMT_STRING, field_data);
}

void ima_show_template_sig(struct seq_file *m, enum ima_show_type show,
			   struct ima_field_data *field_data)
{
	ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data);
}

static int ima_eventdigest_init_common(u8 *digest, u32 digestsize, u8 hash_algo,
				       struct ima_field_data *field_data,
				       bool size_limit)
{
	/*
	 * digest formats:
	 *  - DATA_FMT_DIGEST: digest
	 *  - DATA_FMT_DIGEST_WITH_ALGO: [<hash algo>] + ':' + '\0' + digest,
	 *    where <hash algo> is provided if the hash algoritm is not
	 *    SHA1 or MD5
	 */
	u8 buffer[CRYPTO_MAX_ALG_NAME + 2 + IMA_MAX_DIGEST_SIZE] = { 0 };
	enum data_formats fmt = DATA_FMT_DIGEST;
	u32 offset = 0;

	if (!size_limit) {
		fmt = DATA_FMT_DIGEST_WITH_ALGO;
		if (hash_algo < HASH_ALGO__LAST)
			offset += snprintf(buffer, CRYPTO_MAX_ALG_NAME + 1,
					   "%s", hash_algo_name[hash_algo]);
		buffer[offset] = ':';
		offset += 2;
	}

	if (digest)
		memcpy(buffer + offset, digest, digestsize);
	else
		/*
		 * If digest is NULL, the event being recorded is a violation.
		 * Make room for the digest by increasing the offset of
		 * IMA_DIGEST_SIZE.
		 */
		offset += IMA_DIGEST_SIZE;

	return ima_write_template_field_data(buffer, offset + digestsize,
					     fmt, field_data);
}

/*
 * This function writes the digest of an event (with size limit).
 */
int ima_eventdigest_init(struct integrity_iint_cache *iint, struct file *file,
			 const unsigned char *filename,
			 struct evm_ima_xattr_data *xattr_value, int xattr_len,
			 struct ima_field_data *field_data)
{
	struct {
		struct ima_digest_data hdr;
		char digest[IMA_MAX_DIGEST_SIZE];
	} hash;
	u8 *cur_digest = NULL;
	u32 cur_digestsize = 0;
	struct inode *inode;
	int result;

	memset(&hash, 0, sizeof(hash));

	if (!iint)		/* recording a violation. */
		goto out;

	if (ima_template_hash_algo_allowed(iint->ima_hash->algo)) {
		cur_digest = iint->ima_hash->digest;
		cur_digestsize = iint->ima_hash->length;
		goto out;
	}

	if (!file)		/* missing info to re-calculate the digest */
		return -EINVAL;

	inode = file_inode(file);
	hash.hdr.algo = ima_template_hash_algo_allowed(ima_hash_algo) ?
	    ima_hash_algo : HASH_ALGO_SHA1;
	result = ima_calc_file_hash(file, &hash.hdr);
	if (result) {
		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
				    filename, "collect_data",
				    "failed", result, 0);
		return result;
	}
	cur_digest = hash.hdr.digest;
	cur_digestsize = hash.hdr.length;
out:
	return ima_eventdigest_init_common(cur_digest, cur_digestsize, -1,
					   field_data, true);
}

/*
 * This function writes the digest of an event (without size limit).
 */
int ima_eventdigest_ng_init(struct integrity_iint_cache *iint,
			    struct file *file, const unsigned char *filename,
			    struct evm_ima_xattr_data *xattr_value,
			    int xattr_len, struct ima_field_data *field_data)
{
	u8 *cur_digest = NULL, hash_algo = HASH_ALGO__LAST;
	u32 cur_digestsize = 0;

	/* If iint is NULL, we are recording a violation. */
	if (!iint)
		goto out;

	cur_digest = iint->ima_hash->digest;
	cur_digestsize = iint->ima_hash->length;

	hash_algo = iint->ima_hash->algo;
out:
	return ima_eventdigest_init_common(cur_digest, cur_digestsize,
					   hash_algo, field_data, false);
}

static int ima_eventname_init_common(struct integrity_iint_cache *iint,
				     struct file *file,
				     const unsigned char *filename,
				     struct ima_field_data *field_data,
				     bool size_limit)
{
	const char *cur_filename = NULL;
	u32 cur_filename_len = 0;
	enum data_formats fmt = size_limit ?
	    DATA_FMT_EVENT_NAME : DATA_FMT_STRING;

	BUG_ON(filename == NULL && file == NULL);

	if (filename) {
		cur_filename = filename;
		cur_filename_len = strlen(filename);

		if (!size_limit || cur_filename_len <= IMA_EVENT_NAME_LEN_MAX)
			goto out;
	}

	if (file) {
		cur_filename = file->f_dentry->d_name.name;
		cur_filename_len = strlen(cur_filename);
	} else
		/*
		 * Truncate filename if the latter is too long and
		 * the file descriptor is not available.
		 */
		cur_filename_len = IMA_EVENT_NAME_LEN_MAX;
out:
	return ima_write_template_field_data(cur_filename, cur_filename_len,
					     fmt, field_data);
}

/*
 * This function writes the name of an event (with size limit).
 */
int ima_eventname_init(struct integrity_iint_cache *iint, struct file *file,
		       const unsigned char *filename,
		       struct evm_ima_xattr_data *xattr_value, int xattr_len,
		       struct ima_field_data *field_data)
{
	return ima_eventname_init_common(iint, file, filename,
					 field_data, true);
}

/*
 * This function writes the name of an event (without size limit).
 */
int ima_eventname_ng_init(struct integrity_iint_cache *iint, struct file *file,
			  const unsigned char *filename,
			  struct evm_ima_xattr_data *xattr_value, int xattr_len,
			  struct ima_field_data *field_data)
{
	return ima_eventname_init_common(iint, file, filename,
					 field_data, false);
}

/*
 *  ima_eventsig_init - include the file signature as part of the template data
 */
int ima_eventsig_init(struct integrity_iint_cache *iint, struct file *file,
		      const unsigned char *filename,
		      struct evm_ima_xattr_data *xattr_value, int xattr_len,
		      struct ima_field_data *field_data)
{
	enum data_formats fmt = DATA_FMT_HEX;
	int rc = 0;

	if ((!xattr_value) || (xattr_value->type != EVM_IMA_XATTR_DIGSIG))
		goto out;

	rc = ima_write_template_field_data(xattr_value, xattr_len, fmt,
					   field_data);
out:
	return rc;
}
Commit	Line	Data
3ce1217d RS	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	*/
4d7aeee7 RS	15	#include <crypto/hash_info.h>
4d7aeee7 RS	16
3ce1217d RS	17	#include "ima_template_lib.h"
3ce1217d RS	18
4d7aeee7 RS	19	static 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
	27	enum data_formats {
	28	DATA_FMT_DIGEST = 0,
	29	DATA_FMT_DIGEST_WITH_ALGO,
	30	DATA_FMT_EVENT_NAME,
bcbc9b0c MZ	31	DATA_FMT_STRING,
bcbc9b0c MZ	32	DATA_FMT_HEX
4d7aeee7 RS	33	};
4d7aeee7 RS	34
3ce1217d RS	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)
	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
	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)
	81	{
4d7aeee7 RS	82	u8 *buf_ptr = field_data->data, buflen = field_data->len;
4d7aeee7 RS	83
3ce1217d	84	switch (datafmt) {
4d7aeee7 RS	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;
3ce1217d	93	case DATA_FMT_DIGEST:
bcbc9b0c MZ	94	case DATA_FMT_HEX:
	95	if (!buflen)
	96	break;
4d7aeee7	97	ima_print_digest(m, buf_ptr, buflen);
3ce1217d RS	98	break;
3ce1217d RS	99	case DATA_FMT_STRING:
4d7aeee7	100	seq_printf(m, "%s", buf_ptr);
3ce1217d RS	101	break;
	102	default:
	103	break;
	104	}
	105	}
	106
	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)
	111	{
	112	ima_putc(m, &field_data->len, sizeof(u32));
	113	if (!field_data->len)
	114	return;
	115	ima_putc(m, field_data->data, field_data->len);
	116	}
	117
	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)
	122	{
	123	switch (show) {
	124	case IMA_SHOW_ASCII:
	125	ima_show_template_data_ascii(m, show, datafmt, field_data);
	126	break;
	127	case IMA_SHOW_BINARY:
	128	ima_show_template_data_binary(m, show, datafmt, field_data);
	129	break;
	130	default:
	131	break;
	132	}
	133	}
	134
	135	void ima_show_template_digest(struct seq_file *m, enum ima_show_type show,
	136	struct ima_field_data *field_data)
	137	{
	138	ima_show_template_field_data(m, show, DATA_FMT_DIGEST, field_data);
	139	}
	140
4d7aeee7 RS	141	void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show,
	142	struct ima_field_data *field_data)
	143	{
	144	ima_show_template_field_data(m, show, DATA_FMT_DIGEST_WITH_ALGO,
	145	field_data);
	146	}
	147
3ce1217d RS	148	void ima_show_template_string(struct seq_file *m, enum ima_show_type show,
	149	struct ima_field_data *field_data)
	150	{
	151	ima_show_template_field_data(m, show, DATA_FMT_STRING, field_data);
	152	}
	153
bcbc9b0c MZ	154	void ima_show_template_sig(struct seq_file *m, enum ima_show_type show,
	155	struct ima_field_data *field_data)
	156	{
	157	ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data);
	158	}
	159
4d7aeee7 RS	160	static int ima_eventdigest_init_common(u8 *digest, u32 digestsize, u8 hash_algo,
	161	struct ima_field_data *field_data,
	162	bool size_limit)
	163	{
	164	/*
	165	* digest formats:
	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
	169	* SHA1 or MD5
	170	*/
	171	u8 buffer[CRYPTO_MAX_ALG_NAME + 2 + IMA_MAX_DIGEST_SIZE] = { 0 };
	172	enum data_formats fmt = DATA_FMT_DIGEST;
	173	u32 offset = 0;
	174
	175	if (!size_limit) {
	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] = ':';
	181	offset += 2;
	182	}
	183
	184	if (digest)
	185	memcpy(buffer + offset, digest, digestsize);
	186	else
	187	/*
	188	* If digest is NULL, the event being recorded is a violation.
	189	* Make room for the digest by increasing the offset of
	190	* IMA_DIGEST_SIZE.
	191	*/
	192	offset += IMA_DIGEST_SIZE;
	193
	194	return ima_write_template_field_data(buffer, offset + digestsize,
	195	fmt, field_data);
	196	}
	197
3ce1217d	198	/*
4d7aeee7	199	* This function writes the digest of an event (with size limit).
3ce1217d RS	200	*/
	201	int ima_eventdigest_init(struct integrity_iint_cache iint, struct file file,
	202	const unsigned char *filename,
bcbc9b0c	203	struct evm_ima_xattr_data *xattr_value, int xattr_len,
3ce1217d RS	204	struct ima_field_data *field_data)
	205	{
	206	struct {
	207	struct ima_digest_data hdr;
	208	char digest[IMA_MAX_DIGEST_SIZE];
	209	} hash;
4d7aeee7 RS	210	u8 *cur_digest = NULL;
4d7aeee7 RS	211	u32 cur_digestsize = 0;
3ce1217d RS	212	struct inode *inode;
	213	int result;
	214
	215	memset(&hash, 0, sizeof(hash));
	216
	217	if (!iint) /* recording a violation. */
	218	goto out;
	219
4d7aeee7	220	if (ima_template_hash_algo_allowed(iint->ima_hash->algo)) {
3ce1217d RS	221	cur_digest = iint->ima_hash->digest;
	222	cur_digestsize = iint->ima_hash->length;
	223	goto out;
	224	}
	225
	226	if (!file) /* missing info to re-calculate the digest */
	227	return -EINVAL;
	228
	229	inode = file_inode(file);
4d7aeee7 RS	230	hash.hdr.algo = ima_template_hash_algo_allowed(ima_hash_algo) ?
4d7aeee7 RS	231	ima_hash_algo : HASH_ALGO_SHA1;
3ce1217d RS	232	result = ima_calc_file_hash(file, &hash.hdr);
	233	if (result) {
	234	integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
	235	filename, "collect_data",
	236	"failed", result, 0);
	237	return result;
	238	}
4d7aeee7 RS	239	cur_digest = hash.hdr.digest;
4d7aeee7 RS	240	cur_digestsize = hash.hdr.length;
3ce1217d	241	out:
4d7aeee7 RS	242	return ima_eventdigest_init_common(cur_digest, cur_digestsize, -1,
4d7aeee7 RS	243	field_data, true);
3ce1217d RS	244	}
	245
	246	/*
4d7aeee7	247	* This function writes the digest of an event (without size limit).
3ce1217d	248	*/
4d7aeee7 RS	249	int ima_eventdigest_ng_init(struct integrity_iint_cache *iint,
4d7aeee7 RS	250	struct file file, const unsigned char filename,
bcbc9b0c MZ	251	struct evm_ima_xattr_data *xattr_value,
bcbc9b0c MZ	252	int xattr_len, struct ima_field_data *field_data)
4d7aeee7 RS	253	{
	254	u8 *cur_digest = NULL, hash_algo = HASH_ALGO__LAST;
	255	u32 cur_digestsize = 0;
	256
	257	/* If iint is NULL, we are recording a violation. */
	258	if (!iint)
	259	goto out;
	260
	261	cur_digest = iint->ima_hash->digest;
	262	cur_digestsize = iint->ima_hash->length;
	263
	264	hash_algo = iint->ima_hash->algo;
	265	out:
	266	return ima_eventdigest_init_common(cur_digest, cur_digestsize,
	267	hash_algo, field_data, false);
	268	}
	269
	270	static int ima_eventname_init_common(struct integrity_iint_cache *iint,
	271	struct file *file,
	272	const unsigned char *filename,
	273	struct ima_field_data *field_data,
	274	bool size_limit)
3ce1217d RS	275	{
	276	const char *cur_filename = NULL;
	277	u32 cur_filename_len = 0;
4d7aeee7 RS	278	enum data_formats fmt = size_limit ?
4d7aeee7 RS	279	DATA_FMT_EVENT_NAME : DATA_FMT_STRING;
3ce1217d RS	280
	281	BUG_ON(filename == NULL && file == NULL);
	282
	283	if (filename) {
	284	cur_filename = filename;
	285	cur_filename_len = strlen(filename);
	286
4d7aeee7	287	if (!size_limit \|\| cur_filename_len <= IMA_EVENT_NAME_LEN_MAX)
3ce1217d RS	288	goto out;
	289	}
	290
	291	if (file) {
	292	cur_filename = file->f_dentry->d_name.name;
	293	cur_filename_len = strlen(cur_filename);
	294	} else
	295	/*
	296	* Truncate filename if the latter is too long and
	297	* the file descriptor is not available.
	298	*/
	299	cur_filename_len = IMA_EVENT_NAME_LEN_MAX;
	300	out:
	301	return ima_write_template_field_data(cur_filename, cur_filename_len,
4d7aeee7 RS	302	fmt, field_data);
	303	}
	304
	305	/*
	306	* This function writes the name of an event (with size limit).
	307	*/
	308	int ima_eventname_init(struct integrity_iint_cache iint, struct file file,
	309	const unsigned char *filename,
bcbc9b0c	310	struct evm_ima_xattr_data *xattr_value, int xattr_len,
4d7aeee7 RS	311	struct ima_field_data *field_data)
	312	{
	313	return ima_eventname_init_common(iint, file, filename,
	314	field_data, true);
	315	}
	316
	317	/*
	318	* This function writes the name of an event (without size limit).
	319	*/
	320	int ima_eventname_ng_init(struct integrity_iint_cache iint, struct file file,
	321	const unsigned char *filename,
bcbc9b0c	322	struct evm_ima_xattr_data *xattr_value, int xattr_len,
4d7aeee7 RS	323	struct ima_field_data *field_data)
	324	{
	325	return ima_eventname_init_common(iint, file, filename,
	326	field_data, false);
3ce1217d	327	}
bcbc9b0c MZ	328
	329	/*
	330	* ima_eventsig_init - include the file signature as part of the template data
	331	*/
	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)
	336	{
	337	enum data_formats fmt = DATA_FMT_HEX;
	338	int rc = 0;
	339
	340	if ((!xattr_value) \|\| (xattr_value->type != EVM_IMA_XATTR_DIGSIG))
	341	goto out;
	342
	343	rc = ima_write_template_field_data(xattr_value, xattr_len, fmt,
	344	field_data);
	345	out:
	346	return rc;
	347	}