KeyMint VTS: improve attestation tests

Check that the various ATTESTATION_ID_* tags are included if they
have the correct value, and that keygen fails if they have an invalid
value.

Also update attestation tags to include vendor/boot patchlevel if
they're available. (They always should be, but fixing that is a
separate task.)

Bug: 190757200
Test: VtsAidlKeyMintTargetTest
Merged-In: Ibaed7364c6d08c0982e2a9fb6cb864ae42cf39fe
Change-Id: Ibaed7364c6d08c0982e2a9fb6cb864ae42cf39fe
diff --git a/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.h b/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.h
index 4d31fa4..82f192a 100644
--- a/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.h
+++ b/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.h
@@ -21,6 +21,7 @@
 
 #include <aidl/Gtest.h>
 #include <aidl/Vintf.h>
+#include <android-base/properties.h>
 #include <binder/IServiceManager.h>
 #include <binder/ProcessState.h>
 #include <gtest/gtest.h>
@@ -313,6 +314,16 @@
     long challenge_;
 };
 
+// If the given property is available, add it to the tag set under the given tag ID.
+template <Tag tag>
+void add_tag_from_prop(AuthorizationSetBuilder* tags, TypedTag<TagType::BYTES, tag> ttag,
+                       const char* prop) {
+    std::string prop_value = ::android::base::GetProperty(prop, /* default= */ "");
+    if (!prop_value.empty()) {
+        tags->Authorization(ttag, prop_value.data(), prop_value.size());
+    }
+}
+
 vector<uint8_t> build_serial_blob(const uint64_t serial_int);
 void verify_subject(const X509* cert, const string& subject, bool self_signed);
 void verify_serial(X509* cert, const uint64_t expected_serial);