[PATCH v4 4/8] ima: define a new template field 'd-type' and a new template 'ima-ngv2'

From: Mimi Zohar
Date: Mon Feb 07 2022 - 20:50:42 EST


In preparation to differentiate between regular IMA file hashes and
fs-verity's file digests, define a new template field named 'd-type'.
Define a new template named 'ima-ngv2', which includes the new 'd-type'
field.

Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
---
security/integrity/ima/ima_template.c | 3 +++
security/integrity/ima/ima_template_lib.c | 13 +++++++++++++
security/integrity/ima/ima_template_lib.h | 2 ++
3 files changed, 18 insertions(+)

diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c
index db1ad6d7a57f..b321342e5bee 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -19,6 +19,7 @@ enum header_fields { HDR_PCR, HDR_DIGEST, HDR_TEMPLATE_NAME,
static struct ima_template_desc builtin_templates[] = {
{.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT},
{.name = "ima-ng", .fmt = "d-ng|n-ng"},
+ {.name = "ima-ngv2", .fmt = "d-ng|n-ng|d-type"},
{.name = "ima-sig", .fmt = "d-ng|n-ng|sig"},
{.name = "ima-buf", .fmt = "d-ng|n-ng|buf"},
{.name = "ima-modsig", .fmt = "d-ng|n-ng|sig|d-modsig|modsig"},
@@ -40,6 +41,8 @@ static const 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 = "d-type", .field_init = ima_eventdigest_type_init,
+ .field_show = ima_show_template_string},
{.field_id = "sig", .field_init = ima_eventsig_init,
.field_show = ima_show_template_sig},
{.field_id = "buf", .field_init = ima_eventbuf_init,
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 5a5d462ab36d..48c2fcbefacf 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -386,6 +386,19 @@ int ima_eventdigest_ng_init(struct ima_event_data *event_data,
hash_algo, field_data);
}

+/*
+ * This function writes the digest type of an event.
+ */
+int ima_eventdigest_type_init(struct ima_event_data *event_data,
+ struct ima_field_data *field_data)
+{
+ static const char * const digest_type[] = {"ima"};
+
+ return ima_write_template_field_data(digest_type[0],
+ strlen(digest_type[0]),
+ DATA_FMT_STRING, field_data);
+}
+
/*
* This function writes the digest of the file which is expected to match the
* digest contained in the file's appended signature.
diff --git a/security/integrity/ima/ima_template_lib.h b/security/integrity/ima/ima_template_lib.h
index c71f1de95753..539a5e354925 100644
--- a/security/integrity/ima/ima_template_lib.h
+++ b/security/integrity/ima/ima_template_lib.h
@@ -38,6 +38,8 @@ int ima_eventname_init(struct ima_event_data *event_data,
struct ima_field_data *field_data);
int ima_eventdigest_ng_init(struct ima_event_data *event_data,
struct ima_field_data *field_data);
+int ima_eventdigest_type_init(struct ima_event_data *event_data,
+ struct ima_field_data *field_data);
int ima_eventdigest_modsig_init(struct ima_event_data *event_data,
struct ima_field_data *field_data);
int ima_eventname_ng_init(struct ima_event_data *event_data,
--
2.27.0