From dadb18dd290fb7f6fe3ef3c0b82f83a9c6207e00 Mon Sep 17 00:00:00 2001
From: Paul Crowley <paulcrowley@google.com>
Date: Thu, 29 Apr 2021 10:07:30 -0700
Subject: [PATCH] Add getKeyCharacteristics method to KeyMint

(cherry picked from commit 402d62f7bee0ef162d25543886a5310b1ebb9221)

Bug: 186685601
Test: Treehugger
Merged-In: Ie72d865a37e2b6834fe6a86bf843d30286384aa5
Change-Id: Ie72d865a37e2b6834fe6a86bf843d30286384aa5
---
 .../security/keymint/IKeyMintDevice.aidl      |  1 +
 .../security/keymint/IKeyMintDevice.aidl      | 25 ++++++++++++++++++-
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintDevice.aidl b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintDevice.aidl
index 3f75af6dd0..fa643fc494 100644
--- a/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintDevice.aidl
+++ b/security/keymint/aidl/aidl_api/android.hardware.security.keymint/current/android/hardware/security/keymint/IKeyMintDevice.aidl
@@ -48,5 +48,6 @@ interface IKeyMintDevice {
   void deviceLocked(in boolean passwordOnly, in @nullable android.hardware.security.secureclock.TimeStampToken timestampToken);
   void earlyBootEnded();
   byte[] convertStorageKeyToEphemeral(in byte[] storageKeyBlob);
+  android.hardware.security.keymint.KeyCharacteristics[] getKeyCharacteristics(in byte[] keyBlob, in byte[] appId, in byte[] appData);
   const int AUTH_TOKEN_MAC_LENGTH = 32;
 }
diff --git a/security/keymint/aidl/android/hardware/security/keymint/IKeyMintDevice.aidl b/security/keymint/aidl/android/hardware/security/keymint/IKeyMintDevice.aidl
index a3260f51c6..b4a2bed72d 100644
--- a/security/keymint/aidl/android/hardware/security/keymint/IKeyMintDevice.aidl
+++ b/security/keymint/aidl/android/hardware/security/keymint/IKeyMintDevice.aidl
@@ -20,6 +20,7 @@ import android.hardware.security.keymint.AttestationKey;
 import android.hardware.security.keymint.BeginResult;
 import android.hardware.security.keymint.HardwareAuthToken;
 import android.hardware.security.keymint.IKeyMintOperation;
+import android.hardware.security.keymint.KeyCharacteristics;
 import android.hardware.security.keymint.KeyCreationResult;
 import android.hardware.security.keymint.KeyFormat;
 import android.hardware.security.keymint.KeyMintHardwareInfo;
@@ -766,7 +767,7 @@ interface IKeyMintDevice {
      */
     void earlyBootEnded();
 
-    /*
+    /**
      * Called by the client to get a wrapped per-boot ephemeral key from a wrapped storage key.
      * Clients will then use the returned per-boot ephemeral key in place of the wrapped storage
      * key. Whenever the hardware is presented with a per-boot ephemeral key for an operation, it
@@ -786,4 +787,26 @@ interface IKeyMintDevice {
      *         place of the input storageKeyBlob
      */
     byte[] convertStorageKeyToEphemeral(in byte[] storageKeyBlob);
+
+    /**
+     * Returns parameters associated with the provided key. This should match the
+     * KeyCharacteristics present in the KeyCreationResult returned by generateKey(),
+     * importKey(), or importWrappedKey().
+     *
+     * @param keyBlob The opaque descriptor returned by generateKey, importKey or importWrappedKey.
+     *
+     * @param appId An opaque byte string identifying the client.  This value must match the
+     *        Tag::APPLICATION_ID data provided during key generation/import.  Without the correct
+     *        value, it must be computationally infeasible for the secure hardware to obtain the
+     *        key material.
+     *
+     * @param appData An opaque byte string provided by the application.  This value must match the
+     *        Tag::APPLICATION_DATA data provided during key generation/import.  Without the
+     *        correct value, it must be computationally infeasible for the secure hardware to
+     *        obtain the key material.
+     *
+     * @return Characteristics of the generated key. See KeyCreationResult for details.
+     */
+    KeyCharacteristics[] getKeyCharacteristics(
+            in byte[] keyBlob, in byte[] appId, in byte[] appData);
 }