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Date: Mon, 21 Oct 2013 18:43:01 -0400
From: Mimi Zohar <zohar@...ux.vnet.ibm.com>
To: linux-security-module@...r.kernel.org
Cc: Roberto Sassu <roberto.sassu@...ito.it>,
linux-kernel@...r.kernel.org, James Morris <jmorris@...ei.org>,
David Howells <dhowells@...hat.com>,
Mimi Zohar <zohar@...ux.vnet.ibm.com>
Subject: [PATCH v2 16/23] ima: define new template ima-ng and template fields d-ng and n-ng
From: Roberto Sassu <roberto.sassu@...ito.it>
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: Roberto Sassu <roberto.sassu@...ito.it>
Signed-off-by: Mimi Zohar <zohar@...ux.vnet.ibm.com>
---
security/integrity/ima/ima_template.c | 7 +-
security/integrity/ima/ima_template_lib.c | 152 ++++++++++++++++++++++++++----
security/integrity/ima/ima_template_lib.h | 8 ++
3 files changed, 150 insertions(+), 17 deletions(-)
diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
index 8100422..bf38d1a 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -16,7 +16,8 @@
#include "ima_template_lib.h"
static struct ima_template_desc defined_templates[] = {
- {.name = IMA_TEMPLATE_IMA_NAME,.fmt = IMA_TEMPLATE_IMA_FMT},
+ {.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)
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index e13fc7c..7d84144 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -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)
+{
+ /*
+ * 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.
+ * 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,
- 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)
+{
+ 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);
}
diff --git a/security/integrity/ima/ima_template_lib.h b/security/integrity/ima/ima_template_lib.h
index 2cecc83..16c5e78 100644
--- a/security/integrity/ima/ima_template_lib.h
+++ b/security/integrity/ima/ima_template_lib.h
@@ -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 */
--
1.8.1.4
--
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