[PATCH v2 08/13] security/keys: implement wipe op for trusted and encrypted keys

[Jan Sebastian Götte]

Wipe the decrypted key material and the sealed blob held in the payload.

Used by CONFIG_CRASH_WIPE_SECRETS.

Signed-off-by: Jan Sebastian Götte <linux at jaseg.de>
---
 security/keys/encrypted-keys/encrypted.c  | 13 +++++++++++++
 security/keys/trusted-keys/trusted_core.c | 15 +++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c
index 59cb77b237b3..9d6fe08ecb7a 100644
--- a/security/keys/encrypted-keys/encrypted.c
+++ b/security/keys/encrypted-keys/encrypted.c
@@ -12,6 +12,7 @@
  */
 
 #include <linux/uaccess.h>
+#include <linux/crash_core.h>
 #include <linux/module.h>
 #include <linux/hex.h>
 #include <linux/init.h>
@@ -970,11 +971,23 @@ static void encrypted_destroy(struct key *key)
 	kfree_sensitive(key->payload.data[0]);
 }
 
+static void encrypted_wipe(struct key *key)
+{
+	struct encrypted_key_payload *epayload = key->payload.data[0];
+
+	if (!epayload)
+		return;
+
+	crash_wipe_memzero(epayload->payload_data,
+			   epayload->payload_datalen + epayload->datablob_len);
+}
+
 struct key_type key_type_encrypted = {
 	.name = "encrypted",
 	.instantiate = encrypted_instantiate,
 	.update = encrypted_update,
 	.destroy = encrypted_destroy,
+	.wipe = encrypted_wipe,
 	.describe = user_describe,
 	.read = encrypted_read,
 };
diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
index 0509d9955f2a..7b220c6381b5 100644
--- a/security/keys/trusted-keys/trusted_core.c
+++ b/security/keys/trusted-keys/trusted_core.c
@@ -14,6 +14,7 @@
 #include <keys/trusted_tpm.h>
 #include <keys/trusted_pkwm.h>
 #include <linux/capability.h>
+#include <linux/crash_core.h>
 #include <linux/err.h>
 #include <linux/hex.h>
 #include <linux/init.h>
@@ -325,11 +326,25 @@ static void trusted_destroy(struct key *key)
 	kfree_sensitive(key->payload.data[0]);
 }
 
+static void trusted_wipe(struct key *key)
+{
+	struct trusted_key_payload *p = key->payload.data[0];
+
+	if (!p)
+		return;
+
+	crash_wipe_memzero(p->key, sizeof(p->key));
+	crash_wipe_memzero(p->blob, sizeof(p->blob));
+	p->key_len = 0;
+	p->blob_len = 0;
+}
+
 struct key_type key_type_trusted = {
 	.name = "trusted",
 	.instantiate = trusted_instantiate,
 	.update = trusted_update,
 	.destroy = trusted_destroy,
+	.wipe = trusted_wipe,
 	.describe = user_describe,
 	.read = trusted_read,
 };

-- 
2.53.0