commit 4a489d403e3ebf0360dd1c301df5bc86a288b34c
author Alan Stokes <alanstokes@google.com> Mon Jun 28 10:12:05 2021 +0100
committer Alan Stokes <alanstokes@google.com> Wed Jun 30 13:54:57 2021 +0100
tree 08d99865679f22b22fb2174ee57e4b6a3c71d36b
parent ec74569d3f7b5537fd9eda96c2e95dfd07895a19

Remove now-unnecessary Mutex.

Strong is now Sync (b/164453341), so the Mutex workaround is
redundant.

Bug: 191763370
Test: Manual - builds, key generation & validation still work.
Change-Id: If1cd905046c996569b28377aa1cf325ac5699291

compos/src/compos_key_service.rs

diff --git a/compos/src/compos_key_service.rs b/compos/src/compos_key_service.rs
index 97fd855..0cbe8de 100644
--- a/compos/src/compos_key_service.rs
+++ b/compos/src/compos_key_service.rs
@@ -39,7 +39,6 @@
 use ring::signature;
 use scopeguard::ScopeGuard;
 use std::ffi::CString;
-use std::sync::Mutex;
 
 const LOG_TAG: &str = "CompOsKeyService";
 const OUR_SERVICE_NAME: &str = "android.system.composkeyservice";
@@ -68,10 +67,6 @@
 
 struct CompOsKeyService {
     random: SystemRandom,
-    state: Mutex<State>,
-}
-
-struct State {
     security_level: Strong<dyn IKeystoreSecurityLevel>,
 }
 
@@ -102,20 +97,12 @@
     fn new(keystore_service: &Strong<dyn IKeystoreService>) -> Self {
         Self {
             random: SystemRandom::new(),
-            state: Mutex::new(State {
-                security_level: keystore_service
-                    .getSecurityLevel(SecurityLevel::TRUSTED_ENVIRONMENT)
-                    .unwrap(),
-            }),
+            security_level: keystore_service
+                .getSecurityLevel(SecurityLevel::TRUSTED_ENVIRONMENT)
+                .unwrap(),
         }
     }
 
-    fn security_level(&self) -> Strong<dyn IKeystoreSecurityLevel> {
-        // We need the Mutex because Strong<_> isn't sync. But we don't need to keep it locked
-        // to make the call, once we've cloned the pointer.
-        self.state.lock().unwrap().security_level.clone()
-    }
-
     fn do_generate(&self) -> Result<CompOsKeyData> {
         let key_parameters =
             [PURPOSE_SIGN, ALGORITHM, PADDING, DIGEST, KEY_SIZE, EXPONENT, NO_AUTH_REQUIRED];
@@ -124,7 +111,7 @@
         let entropy = [];
 
         let key_metadata = self
-            .security_level()
+            .security_level
             .generateKey(&KEY_DESCRIPTOR, attestation_key, &key_parameters, flags, &entropy)
             .context("Generating key failed")?;
 
@@ -154,7 +141,7 @@
         let forced = false;
 
         let response = self
-            .security_level()
+            .security_level
             .createOperation(&key_descriptor, &operation_parameters, forced)
             .context("Creating key failed")?;
         let operation = scopeguard::guard(