KeyMint VTS: police Ed25519 msg size limit

Ed25519 signing operations require the secure world to accumulate the
entirety of the message; consequently, impose a limit on message size
for this operation.

Bug: 194358913
Test: VtsAidlKeyMintTargetTest
Change-Id: Ibfb6a54c1d546b5b4e51f42795d2bb4660add772

1 files changed, 6 insertions, 1 deletions

diff --git a/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.cpp b/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.cpp
index 8382781368..49665b10ce 100644
--- a/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.cpp
+++ b/security/keymint/aidl/vts/functional/KeyMintAidlTestBase.cpp
@@ -559,7 +559,12 @@ ErrorCode KeyMintAidlTestBase::Update(const string& input, string* output) {
     std::vector<uint8_t> o_put;
     result = op_->update(vector<uint8_t>(input.begin(), input.end()), {}, {}, &o_put);
 
-    if (result.isOk()) output->append(o_put.begin(), o_put.end());
+    if (result.isOk()) {
+        output->append(o_put.begin(), o_put.end());
+    } else {
+        // Failure always terminates the operation.
+        op_ = {};
+    }
 
     return GetReturnErrorCode(result);
 }