Log key integrity violation to NIAP audit log.

Bug: 183201685
Test: atest MixedDeviceOwnerTest#testSecurityLoggingWithSingleUser
Test: atest keystore2_test
Change-Id: Ic2dbbae818e88c520600c21c5d108cdc4dfca104
diff --git a/keystore2/src/audit_log.rs b/keystore2/src/audit_log.rs
index 30fc155..3d7d26e 100644
--- a/keystore2/src/audit_log.rs
+++ b/keystore2/src/audit_log.rs
@@ -25,14 +25,15 @@
 const TAG_KEY_GENERATED: u32 = 210024;
 const TAG_KEY_IMPORTED: u32 = 210025;
 const TAG_KEY_DESTROYED: u32 = 210026;
+const TAG_KEY_INTEGRITY_VIOLATION: u32 = 210032;
 
-const NAMESPACE_MASK: i64 = 0x80000000;
+const FLAG_NAMESPACE: i64 = 0x80000000;
 
-/// For app domain returns calling app uid, for SELinux domain returns masked namespace.
-fn key_owner(key: &KeyDescriptor, calling_app: uid_t) -> i32 {
-    match key.domain {
-        Domain::APP => calling_app as i32,
-        Domain::SELINUX => (key.nspace | NAMESPACE_MASK) as i32,
+/// Encode key owner as either uid or namespace with a flag.
+fn key_owner(domain: Domain, nspace: i64, uid: i32) -> i32 {
+    match domain {
+        Domain::APP => uid,
+        Domain::SELINUX => (nspace | FLAG_NAMESPACE) as i32,
         _ => {
             log::info!("Not logging audit event for key with unexpected domain");
             0
@@ -55,12 +56,29 @@
     log_key_event(TAG_KEY_DESTROYED, key, calling_app, success);
 }
 
+/// Logs key integrity violation to NIAP audit log.
+pub fn log_key_integrity_violation(key: &KeyDescriptor) {
+    with_log_context(TAG_KEY_INTEGRITY_VIOLATION, |ctx| {
+        let owner = key_owner(key.domain, key.nspace, key.nspace as i32);
+        ctx.append_str(key.alias.as_ref().map_or("none", String::as_str)).append_i32(owner)
+    })
+}
+
 fn log_key_event(tag: u32, key: &KeyDescriptor, calling_app: uid_t, success: bool) {
-    if let Some(ctx) = LogContext::new(LogIdSecurity, tag) {
-        let event = ctx
-            .append_i32(if success { 1 } else { 0 })
+    with_log_context(tag, |ctx| {
+        let owner = key_owner(key.domain, key.nspace, calling_app as i32);
+        ctx.append_i32(if success { 1 } else { 0 })
             .append_str(key.alias.as_ref().map_or("none", String::as_str))
-            .append_i32(key_owner(key, calling_app));
+            .append_i32(owner)
+    })
+}
+
+fn with_log_context<F>(tag: u32, f: F)
+where
+    F: Fn(LogContext) -> LogContext,
+{
+    if let Some(ctx) = LogContext::new(LogIdSecurity, tag) {
+        let event = f(ctx);
         LOGS_HANDLER.queue_lo(move |_| {
             event.write();
         });