[PATCH v2 07/23] ima: differentiate between template hash and file data hash sizes

From: Mimi Zohar
Date: Mon Oct 21 2013 - 18:50:44 EST


The TPM v1.2 limits the template hash size to 20 bytes. This
patch differentiates between the template hash size, as defined
in the ima_template_entry, and the file data hash size, as
defined in the ima_template_data. Subsequent patches add support
for different file data hash algorithms.

Change log:
- hash digest definition in ima_store_template() should be TPM_DIGEST_SIZE

Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxx>
---
security/integrity/ima/ima.h | 2 +-
security/integrity/ima/ima_api.c | 2 +-
security/integrity/ima/ima_crypto.c | 4 ++--
security/integrity/ima/ima_fs.c | 10 +++++-----
security/integrity/ima/ima_init.c | 2 +-
security/integrity/ima/ima_queue.c | 4 ++--
6 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index efcdef2..52393ed 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -49,7 +49,7 @@ struct ima_template_data {
};

struct ima_template_entry {
- u8 digest[IMA_DIGEST_SIZE]; /* sha1 or md5 measurement hash */
+ u8 digest[TPM_DIGEST_SIZE]; /* sha1 or md5 measurement hash */
const char *template_name;
int template_len;
struct ima_template_data template;
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 5a7942e..2cc5dcc 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -46,7 +46,7 @@ int ima_store_template(struct ima_template_entry *entry,
int result;
struct {
struct ima_digest_data hdr;
- char digest[IMA_MAX_DIGEST_SIZE];
+ char digest[TPM_DIGEST_SIZE];
} hash;

memset(entry->digest, 0, sizeof(entry->digest));
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 2fd1786..872c669 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -155,7 +155,7 @@ static void __init ima_pcrread(int idx, u8 *pcr)
*/
int __init ima_calc_boot_aggregate(char *digest)
{
- u8 pcr_i[IMA_DIGEST_SIZE];
+ u8 pcr_i[TPM_DIGEST_SIZE];
int rc, i;
struct {
struct shash_desc shash;
@@ -173,7 +173,7 @@ int __init ima_calc_boot_aggregate(char *digest)
for (i = TPM_PCR0; i < TPM_PCR8; i++) {
ima_pcrread(i, pcr_i);
/* now accumulate with current aggregate */
- rc = crypto_shash_update(&desc.shash, pcr_i, IMA_DIGEST_SIZE);
+ rc = crypto_shash_update(&desc.shash, pcr_i, TPM_DIGEST_SIZE);
}
if (!rc)
crypto_shash_final(&desc.shash, digest);
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index 5f0fd11..c35cfb5 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -133,7 +133,7 @@ static int ima_measurements_show(struct seq_file *m, void *v)
ima_putc(m, &pcr, sizeof pcr);

/* 2nd: template digest */
- ima_putc(m, e->digest, IMA_DIGEST_SIZE);
+ ima_putc(m, e->digest, TPM_DIGEST_SIZE);

/* 3rd: template name size */
namelen = strlen(e->template_name);
@@ -167,11 +167,11 @@ static const struct file_operations ima_measurements_ops = {
.release = seq_release,
};

-static void ima_print_digest(struct seq_file *m, u8 *digest)
+static void ima_print_digest(struct seq_file *m, u8 *digest, int size)
{
int i;

- for (i = 0; i < IMA_DIGEST_SIZE; i++)
+ for (i = 0; i < size; i++)
seq_printf(m, "%02x", *(digest + i));
}

@@ -182,7 +182,7 @@ void ima_template_show(struct seq_file *m, void *e, enum ima_show_type show)

switch (show) {
case IMA_SHOW_ASCII:
- ima_print_digest(m, entry->digest);
+ ima_print_digest(m, entry->digest, IMA_DIGEST_SIZE);
seq_printf(m, " %s\n", entry->file_name);
break;
case IMA_SHOW_BINARY:
@@ -212,7 +212,7 @@ static int ima_ascii_measurements_show(struct seq_file *m, void *v)
seq_printf(m, "%2d ", CONFIG_IMA_MEASURE_PCR_IDX);

/* 2nd: SHA1 template hash */
- ima_print_digest(m, e->digest);
+ ima_print_digest(m, e->digest, TPM_DIGEST_SIZE);

/* 3th: template name */
seq_printf(m, " %s ", e->template_name);
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index 162ea72..9d0243c 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -74,7 +74,7 @@ err_out:

int __init ima_init(void)
{
- u8 pcr_i[IMA_DIGEST_SIZE];
+ u8 pcr_i[TPM_DIGEST_SIZE];
int rc;

ima_used_chip = 0;
diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c
index ff63fe0..e63ff33 100644
--- a/security/integrity/ima/ima_queue.c
+++ b/security/integrity/ima/ima_queue.c
@@ -50,7 +50,7 @@ static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value)
key = ima_hash_key(digest_value);
rcu_read_lock();
hlist_for_each_entry_rcu(qe, &ima_htable.queue[key], hnext) {
- rc = memcmp(qe->entry->digest, digest_value, IMA_DIGEST_SIZE);
+ rc = memcmp(qe->entry->digest, digest_value, TPM_DIGEST_SIZE);
if (rc == 0) {
ret = qe;
break;
@@ -106,7 +106,7 @@ static int ima_pcr_extend(const u8 *hash)
int ima_add_template_entry(struct ima_template_entry *entry, int violation,
const char *op, struct inode *inode)
{
- u8 digest[IMA_DIGEST_SIZE];
+ u8 digest[TPM_DIGEST_SIZE];
const char *audit_cause = "hash_added";
char tpm_audit_cause[AUDIT_CAUSE_LEN_MAX];
int audit_info = 1;
--
1.8.1.4

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