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Subject[PATCH] ima: extend the measurement list to include the file signature
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This patch defines a new template called 'ima-sig', which includes
the file signature in the template data, in addition to the file's
digest and pathname.

A template is composed of a set of fields. Associated with each
field is an initialization and display function. This patch defines
a new template field called 'sig', the initialization function
ima_eventsig_init(), and the display function ima_show_template_sig().

This patch modifies the .field_init() function definition to include
the 'security.ima' extended attribute and length.

Changelog:
- remove unused code (Dmitry Kasatkin)
- avoid calling ima_write_template_field_data() unnecesarily (Roberto Sassu)
- rename DATA_FMT_SIG to DATA_FMT_HEX

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
---
security/integrity/ima/Kconfig | 3 +++
security/integrity/ima/ima.h | 10 +++++---
security/integrity/ima/ima_api.c | 14 +++++++----
security/integrity/ima/ima_init.c | 2 +-
security/integrity/ima/ima_main.c | 3 ++-
security/integrity/ima/ima_template.c | 3 +++
security/integrity/ima/ima_template_lib.c | 39 ++++++++++++++++++++++++++++---
security/integrity/ima/ima_template_lib.h | 12 +++++++++-
8 files changed, 73 insertions(+), 13 deletions(-)

diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig
index 351a58e..81a2797 100644
--- a/security/integrity/ima/Kconfig
+++ b/security/integrity/ima/Kconfig
@@ -63,6 +63,8 @@ choice
bool "ima"
config IMA_NG_TEMPLATE
bool "ima-ng (default)"
+ config IMA_SIG_TEMPLATE
+ bool "ima-sig"
endchoice

config IMA_DEFAULT_TEMPLATE
@@ -70,6 +72,7 @@ config IMA_DEFAULT_TEMPLATE
depends on IMA
default "ima" if IMA_TEMPLATE
default "ima-ng" if IMA_NG_TEMPLATE
+ default "ima-sig" if IMA_SIG_TEMPLATE

choice
prompt "Default integrity hash algorithm"
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 72d013e..bf03c6a 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -59,7 +59,8 @@ struct ima_template_field {
const char field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN];
int (*field_init) (struct integrity_iint_cache *iint, struct file *file,
const unsigned char *filename,
- struct ima_field_data *field_data);
+ struct evm_ima_xattr_data *xattr_value,
+ int xattr_len, struct ima_field_data *field_data);
void (*field_show) (struct seq_file *m, enum ima_show_type show,
struct ima_field_data *field_data);
};
@@ -134,12 +135,15 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
struct evm_ima_xattr_data **xattr_value,
int *xattr_len);
void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
- const unsigned char *filename);
+ const unsigned char *filename,
+ struct evm_ima_xattr_data *xattr_value,
+ int xattr_len);
void ima_audit_measurement(struct integrity_iint_cache *iint,
const unsigned char *filename);
int ima_alloc_init_template(struct integrity_iint_cache *iint,
struct file *file, const unsigned char *filename,
- struct ima_template_entry **entry);
+ struct evm_ima_xattr_data *xattr_value,
+ int xattr_len, struct ima_template_entry **entry);
int ima_store_template(struct ima_template_entry *entry, int violation,
struct inode *inode, const unsigned char *filename);
const char *ima_d_path(struct path *path, char **pathbuf);
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 5fcc806..0e75408 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -26,7 +26,8 @@
*/
int ima_alloc_init_template(struct integrity_iint_cache *iint,
struct file *file, const unsigned char *filename,
- struct ima_template_entry **entry)
+ struct evm_ima_xattr_data *xattr_value,
+ int xattr_len, struct ima_template_entry **entry)
{
struct ima_template_desc *template_desc = ima_template_desc_current();
int i, result = 0;
@@ -41,6 +42,7 @@ int ima_alloc_init_template(struct integrity_iint_cache *iint,
u32 len;

result = field->field_init(iint, file, filename,
+ xattr_value, xattr_len,
&((*entry)->template_data[i]));
if (result != 0)
goto out;
@@ -123,7 +125,8 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
/* can overflow, only indicator */
atomic_long_inc(&ima_htable.violations);

- result = ima_alloc_init_template(NULL, file, filename, &entry);
+ result = ima_alloc_init_template(NULL, file, filename,
+ NULL, 0, &entry);
if (result < 0) {
result = -ENOMEM;
goto err_out;
@@ -239,7 +242,9 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
* Must be called with iint->mutex held.
*/
void ima_store_measurement(struct integrity_iint_cache *iint,
- struct file *file, const unsigned char *filename)
+ struct file *file, const unsigned char *filename,
+ struct evm_ima_xattr_data *xattr_value,
+ int xattr_len)
{
const char *op = "add_template_measure";
const char *audit_cause = "ENOMEM";
@@ -251,7 +256,8 @@ void ima_store_measurement(struct integrity_iint_cache *iint,
if (iint->flags & IMA_MEASURED)
return;

- result = ima_alloc_init_template(iint, file, filename, &entry);
+ result = ima_alloc_init_template(iint, file, filename,
+ xattr_value, xattr_len, &entry);
if (result < 0) {
integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
op, audit_cause, result, 0);
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index f84aec5..15f34bd 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -69,7 +69,7 @@ static void __init ima_add_boot_aggregate(void)
}

result = ima_alloc_init_template(iint, NULL, boot_aggregate_name,
- &entry);
+ NULL, 0, &entry);
if (result < 0)
return;

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 14d4cb5..149ee11 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -225,7 +225,8 @@ static int process_measurement(struct file *file, const char *filename,
pathname = (const char *)file->f_dentry->d_name.name;

if (action & IMA_MEASURE)
- ima_store_measurement(iint, file, pathname);
+ ima_store_measurement(iint, file, pathname,
+ xattr_value, xattr_len);
if (action & IMA_APPRAISE_SUBMASK)
rc = ima_appraise_measurement(_func, iint, file, pathname,
xattr_value, xattr_len);
diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
index 0002214..4e5da99 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -20,6 +20,7 @@
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"},
+ {.name = "ima-sig",.fmt = "d-ng|n-ng|sig"},
};

static struct ima_template_field supported_fields[] = {
@@ -31,6 +32,8 @@ static struct ima_template_field supported_fields[] = {
.field_show = ima_show_template_digest_ng},
{.field_id = "n-ng",.field_init = ima_eventname_ng_init,
.field_show = ima_show_template_string},
+ {.field_id = "sig",.field_init = ima_eventsig_init,
+ .field_show = ima_show_template_sig},
};

static struct ima_template_desc *ima_template;
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 7d84144..0da8545 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -28,14 +28,15 @@ enum data_formats {
DATA_FMT_DIGEST = 0,
DATA_FMT_DIGEST_WITH_ALGO,
DATA_FMT_EVENT_NAME,
- DATA_FMT_STRING
+ 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;
+ u8 *buf = NULL, *buf_ptr;
u32 buflen;

switch (datafmt) {
@@ -90,6 +91,9 @@ static void ima_show_template_data_ascii(struct seq_file *m,
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:
@@ -147,6 +151,12 @@ void ima_show_template_string(struct seq_file *m, enum ima_show_type show,
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)
@@ -190,6 +200,7 @@ static int ima_eventdigest_init_common(u8 *digest, u32 digestsize, u8 hash_algo,
*/
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 {
@@ -237,7 +248,8 @@ out:
*/
int ima_eventdigest_ng_init(struct integrity_iint_cache *iint,
struct file *file, const unsigned char *filename,
- struct ima_field_data *field_data)
+ 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;
@@ -295,6 +307,7 @@ out:
*/
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,
@@ -306,8 +319,28 @@ int ima_eventname_init(struct integrity_iint_cache *iint, struct file *file,
*/
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;
+
+ if (!xattr_value)
+ return 0;
+
+ if (xattr_value->type == EVM_IMA_XATTR_DIGSIG)
+ return ima_write_template_field_data(xattr_value, xattr_len,
+ fmt, field_data);
+ return 0;
+}
diff --git a/security/integrity/ima/ima_template_lib.h b/security/integrity/ima/ima_template_lib.h
index 16c5e78..63f6b52 100644
--- a/security/integrity/ima/ima_template_lib.h
+++ b/security/integrity/ima/ima_template_lib.h
@@ -24,16 +24,26 @@ 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);
+void ima_show_template_sig(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,
const unsigned char *filename,
+ struct evm_ima_xattr_data *xattr_value, int xattr_len,
struct ima_field_data *field_data);
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);
int ima_eventdigest_ng_init(struct integrity_iint_cache *iint,
struct file *file, const unsigned char *filename,
- struct ima_field_data *field_data);
+ struct evm_ima_xattr_data *xattr_value,
+ int xattr_len, struct ima_field_data *field_data);
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);
+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);
#endif /* __LINUX_IMA_TEMPLATE_LIB_H */
--
1.8.1.4




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