Fix reported `TxID` term during public recovery (#2879)

src/crypto/symmetric_key.h

@@ -24,17 +24,21 @@ namespace crypto
     constexpr static size_t RAW_DATA_SIZE = sizeof(tag) + sizeof(iv);
 
     GcmHeader() = default;
-    GcmHeader(const std::vector<uint8_t>& data)
+    GcmHeader(const uint8_t* data, size_t size)
     {
-      if (data.size() != RAW_DATA_SIZE)
+      if (size != RAW_DATA_SIZE)
       {
         throw std::logic_error("Incompatible IV size");
       }
 
-      memcpy(tag, data.data(), sizeof(tag));
-      memcpy(iv, data.data() + sizeof(tag), sizeof(iv));
+      memcpy(tag, data, sizeof(tag));
+      memcpy(iv, data + sizeof(tag), sizeof(iv));
     }
 
+    GcmHeader(const std::vector<uint8_t>& data) :
+      GcmHeader(data.data(), data.size())
+    {}
+
     void set_iv_seq(uint64_t seq)
     {
       *reinterpret_cast<uint64_t*>(iv) = seq;

src/kv/deserialise.h

@@ -61,8 +61,8 @@ namespace kv
 
     ApplyResult apply() override
     {
-      kv::Version max_conflict_version;
-      kv::Term view;
+      kv::Version max_conflict_version = 0;
+      kv::Term view = 0;
       if (!store->fill_maps(
             data,
             public_only,

src/kv/encryptor.h

@@ -40,6 +40,11 @@ namespace kv
       return S::RAW_DATA_SIZE;
     }
 
+    uint64_t get_term(const uint8_t* data, size_t size) override
+    {
+      return S(data, size).get_term();
+    }
+
     /**
      * Encrypt data and return serialised GCM header and cipher.
      *

src/kv/generic_serialise_wrapper.h

@@ -282,7 +282,7 @@ namespace kv
       }
 
       // If the kv store has no encryptor, assume that the serialised tx is
-      // public only with no header
+      // public only with no header (test only)
       if (!crypto_util)
       {
         public_reader.init(data_, size_);
@@ -303,6 +303,12 @@ namespace kv
         domain_restriction.has_value() &&
         domain_restriction.value() == SecurityDomain::PUBLIC)
       {
+        // Retrieve term from GCM header, even if the domain restriction is set
+        // to public and the decryption is skipped, so that the term for the
+        // deserialised entry can be reported
+        term =
+          crypto_util->get_term(gcm_hdr_data, crypto_util->get_header_length());
+
         return std::make_tuple(version, max_conflict_version);
       }
 

src/kv/kv_types.h

@@ -521,6 +521,7 @@ namespace kv
     virtual void rollback(Version version) = 0;
 
     virtual size_t get_header_length() = 0;
+    virtual uint64_t get_term(const uint8_t* data, size_t size) = 0;
   };
 
   using EncryptorPtr = std::shared_ptr<AbstractTxEncryptor>;

src/kv/test/null_encryptor.h

@@ -40,6 +40,11 @@ namespace kv
       return 0;
     }
 
+    uint64_t get_term(const uint8_t* data, size_t size) override
+    {
+      return 0;
+    }
+
     void rollback(Version version) override {}
   };
 }