Extract describe_cose_receipt_v1 into reusable API

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Added
 
+- Added `ccf::describe_cose_receipt(receipt)` to obtain COSE receipts with Merkle proof in unprotected header for non-signature TXs, and empty unprotected header for signature TXs (#7700).
 - `NetworkIdentitySubsystemInterface` now exposes `get_trusted_keys()`, returning all trusted network identity keys as a `TrustedKeys` map (#7690).
 
 ### Changed

include/ccf/receipt.h

@@ -156,10 +156,13 @@ namespace ccf
   using SerialisedCoseEndorsement = std::vector<uint8_t>;
   using SerialisedCoseSignature = std::vector<uint8_t>;
   using SerialisedCoseEndorsements = std::vector<SerialisedCoseEndorsement>;
+  using SerialisedCoseReceipt = std::vector<uint8_t>;
   std::optional<SerialisedCoseEndorsements> describe_cose_endorsements_v1(
     const TxReceiptImpl& receipt);
   std::optional<SerialisedCoseSignature> describe_cose_signature_v1(
     const TxReceiptImpl& receipt);
+  std::optional<SerialisedCoseReceipt> describe_cose_receipt(
+    const TxReceiptImpl& receipt);
 
   // Manual JSON serializers are specified for these types as they are not
   // trivial POD structs

samples/apps/logging/logging.cpp

@@ -2178,41 +2178,23 @@ namespace loggingapp
       auto get_cose_receipt = [](
                                 ccf::endpoints::ReadOnlyEndpointContext& ctx,
                                 ccf::historical::StatePtr historical_state) {
-        auto historical_tx = historical_state->store->create_read_only_tx();
-
         assert(historical_state->receipt);
-        auto signature = describe_cose_signature_v1(*historical_state->receipt);
-        if (!signature.has_value())
-        {
-          ctx.rpc_ctx->set_error(
-            HTTP_STATUS_NOT_FOUND,
-            ccf::errors::ResourceNotFound,
-            "No COSE signature available for this transaction");
-          return;
-        }
-        auto proof = describe_merkle_proof_v1(*historical_state->receipt);
-        if (!proof.has_value())
+        auto cose_receipt =
+          describe_cose_receipt(*historical_state->receipt);
+        if (!cose_receipt.has_value())
         {
           ctx.rpc_ctx->set_error(
             HTTP_STATUS_NOT_FOUND,
             ccf::errors::ResourceNotFound,
-            "No merkle proof available for this transaction");
+            "No COSE receipt available for this transaction");
           return;
         }
 
-        constexpr int64_t vdp = 396;
-        auto inclusion_proof = ccf::cose::edit::pos::AtKey{-1};
-
-        ccf::cose::edit::desc::Value desc{inclusion_proof, vdp, *proof};
-
-        auto cose_receipt =
-          ccf::cose::edit::set_unprotected_header(*signature, desc);
-
         ctx.rpc_ctx->set_response_status(HTTP_STATUS_OK);
         ctx.rpc_ctx->set_response_header(
           ccf::http::headers::CONTENT_TYPE,
           ccf::http::headervalues::contenttype::COSE);
-        ctx.rpc_ctx->set_response_body(cose_receipt);
+        ctx.rpc_ctx->set_response_body(*cose_receipt);
       };
       make_read_only_endpoint(
         "/log/public/cose_receipt",

src/node/historical_queries_adapter.cpp

@@ -3,10 +3,12 @@
 
 #include "ccf/historical_queries_adapter.h"
 
+#include "ccf/crypto/cose.h"
 #include "ccf/historical_queries_utils.h"
 #include "ccf/rpc_context.h"
 #include "ccf/service/tables/service.h"
 #include "crypto/cbor.h"
+#include "crypto/cose.h"
 #include "kv/kv_types.h"
 #include "node/rpc/network_identity_subsystem.h"
 #include "node/tx_receipt_impl.h"
@@ -253,6 +255,30 @@ namespace ccf
   {
     return receipt.cose_signature;
   }
+
+  std::optional<SerialisedCoseReceipt> describe_cose_receipt(
+    const TxReceiptImpl& receipt)
+  {
+    auto signature = describe_cose_signature_v1(receipt);
+    if (!signature.has_value())
+    {
+      return std::nullopt;
+    }
+
+    auto proof = describe_merkle_proof_v1(receipt);
+    if (!proof.has_value())
+    {
+      // Signature TX: return COSE signature as-is, with empty UHDR
+      return *signature;
+    }
+
+    auto inclusion_proof =
+      ccf::cose::edit::pos::AtKey{ccf::cose::header::iana::INCLUSION_PROOFS};
+    ccf::cose::edit::desc::Value desc{
+      inclusion_proof, ccf::cose::header::iana::VDP, *proof};
+
+    return ccf::cose::edit::set_unprotected_header(*signature, desc);
+  }
 }
 
 namespace ccf::historical

tests/e2e_logging.py

@@ -910,10 +910,17 @@ def test_cbor_receipts(network, args):
                     log_capture=[],  # Do not emit raw binary to stdout
                 )
                 if r.status_code == http.HTTPStatus.OK:
-                    found_receipt = True
                     cose_receipt = r.body.data()
                     uhdr = cbor2.loads(cose_receipt).value[1]
-                    proofs = uhdr[396][-1]
+                    VDP_KEY = 396  # ccf::cose::header::iana::VDP
+                    if VDP_KEY not in uhdr:
+                        # Signature TX: valid receipt with empty UHDR, skip to next seqno
+                        LOG.debug(
+                            f"Transaction {txid} is a signature TX (empty UHDR), skipping"
+                        )
+                        break
+                    found_receipt = True
+                    proofs = uhdr[VDP_KEY][-1]
                     assert len(proofs) > 0, "No Merkle proofs found in receipt"
 
                     r = client.get(