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Commit 4d7aeee7 authored by Roberto Sassu's avatar Roberto Sassu Committed by Mimi Zohar
Browse files

ima: define new template ima-ng and template fields d-ng and n-ng 



This patch adds support for the new template 'ima-ng', whose format
is defined as 'd-ng|n-ng'.  These new field definitions remove the
size limitations of the original 'ima' template.  Further, the 'd-ng'
field prefixes the inode digest with the hash algorithim, when
displaying the new larger digest sizes.

Change log:
- scripts/Lindent fixes  - Mimi
- "always true comparison" - reported by Fengguang Wu, resolved Dmitry
- initialize hash_algo variable to HASH_ALGO__LAST
- always prefix digest with hash algorithm - Mimi

Signed-off-by: default avatarRoberto Sassu <roberto.sassu@polito.it>
Signed-off-by: default avatarMimi Zohar <zohar@linux.vnet.ibm.com>
parent 3ce1217d

security/integrity/ima/ima_template.c

+6 −1
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 


static struct ima_template_desc defined_templates[] = {

	{.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT},

	{.name = "ima-ng",.fmt = "d-ng|n-ng"},

};



static struct ima_template_field supported_fields[] = {
@@ -24,6 +25,10 @@ static struct ima_template_field supported_fields[] = { 
	 .field_show = ima_show_template_digest},

	{.field_id = "n",.field_init = ima_eventname_init,

	 .field_show = ima_show_template_string},

	{.field_id = "d-ng",.field_init = ima_eventdigest_ng_init,

	 .field_show = ima_show_template_digest_ng},

	{.field_id = "n-ng",.field_init = ima_eventname_ng_init,

	 .field_show = ima_show_template_string},

};



static struct ima_template_field *lookup_template_field(const char *field_id)

security/integrity/ima/ima_template_lib.c

+136 −16
Original line number Diff line number Diff line
@@ -12,9 +12,25 @@ 
 * File: ima_template_lib.c

 *      Library of supported template fields.

 */

#include <crypto/hash_info.h>



#include "ima_template_lib.h"



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

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

};



static int ima_write_template_field_data(const void *data, const u32 datalen,

					 enum data_formats datafmt,

					 struct ima_field_data *field_data)
@@ -62,12 +78,22 @@ static void ima_show_template_data_ascii(struct seq_file *m, 
					 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:

		ima_print_digest(m, field_data->data, field_data->len);

		ima_print_digest(m, buf_ptr, buflen);

		break;

	case DATA_FMT_STRING:

		seq_printf(m, "%s", field_data->data);

		seq_printf(m, "%s", buf_ptr);

		break;

	default:

		break;
@@ -108,14 +134,59 @@ void ima_show_template_digest(struct seq_file *m, enum ima_show_type show, 
	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);

}



static int ima_eventdigest_init_common(u8 *digest, u32 digestsize, u8 hash_algo,

				       struct ima_field_data *field_data,

				       bool size_limit)

{

	/*

 * This function writes the digest of an event.

	 * 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,
@@ -125,8 +196,8 @@ int ima_eventdigest_init(struct integrity_iint_cache *iint, struct file *file, 
		struct ima_digest_data hdr;

		char digest[IMA_MAX_DIGEST_SIZE];

	} hash;

	u8 *cur_digest = hash.hdr.digest;

	u32 cur_digestsize = IMA_DIGEST_SIZE;

	u8 *cur_digest = NULL;

	u32 cur_digestsize = 0;

	struct inode *inode;

	int result;
@@ -135,7 +206,7 @@ int ima_eventdigest_init(struct integrity_iint_cache *iint, struct file *file, 
	if (!iint)		/* recording a violation. */

		goto out;



	if (iint->ima_hash->algo == ima_hash_algo) {

	if (ima_template_hash_algo_allowed(iint->ima_hash->algo)) {

		cur_digest = iint->ima_hash->digest;

		cur_digestsize = iint->ima_hash->length;

		goto out;
@@ -145,7 +216,8 @@ int ima_eventdigest_init(struct integrity_iint_cache *iint, struct file *file, 
		return -EINVAL;



	inode = file_inode(file);

	hash.hdr.algo = ima_hash_algo;

	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,
@@ -153,20 +225,46 @@ int ima_eventdigest_init(struct integrity_iint_cache *iint, struct file *file, 
				    "failed", result, 0);

		return result;

	}

	cur_digest = hash.hdr.digest;

	cur_digestsize = hash.hdr.length;

out:

	return ima_write_template_field_data(cur_digest, cur_digestsize,

					     DATA_FMT_DIGEST, field_data);

	return ima_eventdigest_init_common(cur_digest, cur_digestsize, -1,

					   field_data, true);

}



/*

 * This function writes the name of an event.

 * This function writes the digest of an event (without size limit).

 */

int ima_eventname_init(struct integrity_iint_cache *iint, struct file *file,

		       const unsigned char *filename,

int ima_eventdigest_ng_init(struct integrity_iint_cache *iint,

			    struct file *file, const unsigned char *filename,

			    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);
@@ -174,7 +272,7 @@ int ima_eventname_init(struct integrity_iint_cache *iint, struct file *file, 
		cur_filename = filename;

		cur_filename_len = strlen(filename);



		if (cur_filename_len <= IMA_EVENT_NAME_LEN_MAX)

		if (!size_limit || cur_filename_len <= IMA_EVENT_NAME_LEN_MAX)

			goto out;

	}
@@ -189,5 +287,27 @@ int ima_eventname_init(struct integrity_iint_cache *iint, struct file *file, 
		cur_filename_len = IMA_EVENT_NAME_LEN_MAX;

out:

	return ima_write_template_field_data(cur_filename, cur_filename_len,

					     DATA_FMT_EVENT_NAME, field_data);

					     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 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 ima_field_data *field_data)

{

	return ima_eventname_init_common(iint, file, filename,

					 field_data, false);

}

security/integrity/ima/ima_template_lib.h

+8 −0
Original line number Diff line number Diff line
@@ -20,6 +20,8 @@ 


void ima_show_template_digest(struct seq_file *m, enum ima_show_type show,

			      struct ima_field_data *field_data);

void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show,

				 struct ima_field_data *field_data);

void ima_show_template_string(struct seq_file *m, enum ima_show_type show,

			      struct ima_field_data *field_data);

int ima_eventdigest_init(struct integrity_iint_cache *iint, struct file *file,
@@ -28,4 +30,10 @@ int ima_eventdigest_init(struct integrity_iint_cache *iint, struct file *file, 
int ima_eventname_init(struct integrity_iint_cache *iint, struct file *file,

		       const unsigned char *filename,

		       struct ima_field_data *field_data);

int ima_eventdigest_ng_init(struct integrity_iint_cache *iint,

			    struct file *file, const unsigned char *filename,

			    struct ima_field_data *field_data);

int ima_eventname_ng_init(struct integrity_iint_cache *iint, struct file *file,

			  const unsigned char *filename,

			  struct ima_field_data *field_data);

#endif /* __LINUX_IMA_TEMPLATE_LIB_H */