Addressed review comments

CHANGELOG.md

@@ -1,7 +1,7 @@
 # Changelog
 
 ## Unreleased changes
-- Added support for GRPC V2 `GetBlockCertificates` for retrieving certificates for a block supporting ConcordiumBFT
+- Added support for GRPC V2 `GetBlockCertificates` for retrieving certificates for a block supporting ConcordiumBF, i.e. a node with at least version 6.1.
 
 ## 5.1.0
 - Fixed a regression that made it harder to deserialize transactions from bytes.

concordium-sdk/src/main/java/com/concordium/sdk/ClientV2.java

@@ -778,7 +778,7 @@ public InvokeInstanceResult invokeInstance(InvokeInstanceRequest request) {
 
     /**
      * Retrieves the {@link BlockCertificates} for a given block.
-     * Note that, if the block being pointed to is not a product of ConcordiumBFT, then a INVALID_ARGUMENT exception will be thrown.
+     * Note that, if the block being pointed to is not a product of ConcordiumBFT, i.e. created before protocol version 6, then a INVALID_ARGUMENT exception will be thrown.
      * If the endpoint is not enabled by the node, then an 'UNIMPLEMENTED' exception will be thrown.
      * @param block The block to query
      * @return {@link BlockCertificates} of the block.

concordium-sdk/src/main/java/com/concordium/sdk/crypto/BLSSignature.java

@@ -0,0 +1,33 @@
+package com.concordium.sdk.crypto;
+
+import lombok.Builder;
+import lombok.EqualsAndHashCode;
+import lombok.ToString;
+
+import java.util.Arrays;
+
+@EqualsAndHashCode
+@ToString(includeFieldNames = false)
+public class BLSSignature {
+
+    private static final int FIXED_LENGTH = 48;
+
+    /**
+     * The bytes representing the raw aggregate signature. The bytes have a fixed length of {@value BLSSignature#FIXED_LENGTH} bytes.
+     */
+    private final byte[] bytes;
+
+    private BLSSignature(final byte[] bytes) {
+        this.bytes = bytes;
+    }
+
+    @Builder
+    public static BLSSignature from(final byte[] sig) {
+        if (! (sig.length == 48)) {throw new IllegalArgumentException("BLSSignature must have fixed length of " + FIXED_LENGTH + " bytes"); }
+        return new BLSSignature(sig);
+    }
+
+    public byte[] getBytes() {
+        return Arrays.copyOf(bytes, bytes.length);
+    }
+}

concordium-sdk/src/main/java/com/concordium/sdk/responses/blockcertificates/BlockCertificates.java

@@ -1,11 +1,13 @@
 package com.concordium.sdk.responses.blockcertificates;
 
+import com.concordium.sdk.responses.Round;
 import lombok.*;
 
 import java.util.Optional;
 
 /**
  * Certificates for a block for protocols supporting ConcordiumBFT.
+ * ConcordiumBFT progresses to a new {@link Round} either via a {@link QuorumCertificate} or a {@link TimeoutCertificate} for a particular round.
  */
 @EqualsAndHashCode
 @Builder

concordium-sdk/src/main/java/com/concordium/sdk/responses/blockcertificates/EpochFinalizationEntry.java

@@ -14,7 +14,6 @@
 @Getter
 @ToString
 @EqualsAndHashCode
-
 public class EpochFinalizationEntry {
     /**
      * The quorum certificate for the finalized block.

concordium-sdk/src/main/java/com/concordium/sdk/responses/blockcertificates/QuorumSignature.java

@@ -1,5 +1,6 @@
 package com.concordium.sdk.responses.blockcertificates;
 
+import com.concordium.sdk.crypto.BLSSignature;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -15,16 +16,18 @@
 public class QuorumSignature {
 
     /**
-     * The bytes representing the raw aggregate signature. The bytes have a fixed length of 48 bytes.
+     * The aggregate {@link BLSSignature}.
      */
-    private final byte[] value;
+    private final BLSSignature value;
 
     /**
      * Parses {@link com.concordium.grpc.v2.QuorumSignature} to {@link QuorumSignature}.
      * @param sig {@link com.concordium.grpc.v2.QuorumSignature} returned by the GRPC v2 API.
      * @return parsed {@link QuorumSignature}.
      */
     public static QuorumSignature from(com.concordium.grpc.v2.QuorumSignature sig) {
-        return QuorumSignature.builder().value(sig.getValue().toByteArray()).build();
+        return QuorumSignature.builder()
+                .value(BLSSignature.from(sig.getValue().toByteArray()))
+                .build();
     }
 }

concordium-sdk/src/main/java/com/concordium/sdk/responses/blockcertificates/SuccessorProof.java

@@ -1,5 +1,6 @@
 package com.concordium.sdk.responses.blockcertificates;
 
+import com.concordium.sdk.transactions.Hash;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -16,16 +17,16 @@
 @ToString
 public class SuccessorProof {
     /**
-     * The proof represented as raw bytes. The bytes have a fixed length of 32 bytes.
+     * The proof.
      */
-    private final byte[] value;
+    private final Hash value;
 
     /**
      * Parses {@link com.concordium.grpc.v2.SuccessorProof} to {@link SuccessorProof}.
      * @param proof {@link com.concordium.grpc.v2.SuccessorProof} returned by the GRCP v2 API.
      * @return parsed {@link SuccessorProof}.
      */
     public static SuccessorProof from(com.concordium.grpc.v2.SuccessorProof proof) {
-        return SuccessorProof.builder().value(proof.getValue().toByteArray()).build();
+        return SuccessorProof.builder().value(Hash.from(proof.getValue().toByteArray())).build();
     }
 }

concordium-sdk/src/main/java/com/concordium/sdk/responses/blockcertificates/TimeoutSignature.java

@@ -1,5 +1,6 @@
 package com.concordium.sdk.responses.blockcertificates;
 
+import com.concordium.sdk.crypto.BLSSignature;
 import lombok.Builder;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -14,16 +15,18 @@
 @EqualsAndHashCode
 public class TimeoutSignature {
     /**
-     * The bytes representing the raw aggregate signature. The bytes have a fixed length of 48 bytes.
+     * The aggregate {@link BLSSignature}.
      */
-    private final byte[] value;
+    private final BLSSignature value;
 
     /**
      * Parses {@link com.concordium.grpc.v2.TimeoutSignature} to {@link TimeoutSignature}.
      * @param sig {@link com.concordium.grpc.v2.TimeoutSignature} returned by the GRCP v2 API.
      * @return parsed {@link TimeoutSignature}.
      */
     public static TimeoutSignature from(com.concordium.grpc.v2.TimeoutSignature sig) {
-        return TimeoutSignature.builder().value(sig.getValue().toByteArray()).build();
+        return TimeoutSignature.builder()
+                .value(BLSSignature.from(sig.getValue().toByteArray()))
+                .build();
     }
 }

concordium-sdk/src/test/java/com/concordium/sdk/ClientV2GetBlockCertificatesTest.java

@@ -1,6 +1,7 @@
 package com.concordium.sdk;
 
 import com.concordium.grpc.v2.*;
+import com.concordium.sdk.crypto.BLSSignature;
 import com.concordium.sdk.requests.BlockQuery;
 import com.concordium.sdk.responses.BakerId;
 import com.concordium.sdk.responses.Epoch;
@@ -100,7 +101,7 @@ public class ClientV2GetBlockCertificatesTest {
                     .round(Round.from(ROUND_1))
                     .epoch(Epoch.from(EPOCH_1))
                     .aggregateSignature(com.concordium.sdk.responses.blockcertificates.QuorumSignature
-                            .builder().value(QUORUM_SIG_1)
+                            .builder().value(BLSSignature.from(QUORUM_SIG_1))
                             .build())
                     .signatories(CLIENT_BAKER_ID_LIST_1)
                     .build();
@@ -110,7 +111,7 @@ public class ClientV2GetBlockCertificatesTest {
                     .round(Round.from(ROUND_2))
                     .epoch(Epoch.from(EPOCH_2))
                     .aggregateSignature(com.concordium.sdk.responses.blockcertificates.QuorumSignature
-                            .builder().value(QUORUM_SIG_2)
+                            .builder().value(BLSSignature.from(QUORUM_SIG_2))
                             .build())
                     .signatories(CLIENT_BAKER_ID_LIST_2)
                     .build();
@@ -122,7 +123,7 @@ public class ClientV2GetBlockCertificatesTest {
                     .qcRoundsFirstEpoch(CLIENT_FINALIZER_ROUND_LIST_1)
                     .qcRoundsSecondEpoch(CLIENT_FINALIZER_ROUND_LIST_2)
                     .aggregateSignature(com.concordium.sdk.responses.blockcertificates.TimeoutSignature
-                            .builder().value(TIMEOUT_SIG_1)
+                            .builder().value(BLSSignature.from(TIMEOUT_SIG_1))
                             .build())
                     .build();
 
@@ -131,7 +132,7 @@ public class ClientV2GetBlockCertificatesTest {
                     .finalizedQc(CLIENT_QUORUM_CERTIFICATE_1)
                     .successorQc(CLIENT_QUORUM_CERTIFICATE_2)
                     .successorProof(com.concordium.sdk.responses.blockcertificates.SuccessorProof
-                            .builder().value(SUCCESSOR_PROOF_1).build())
+                            .builder().value(Hash.from(SUCCESSOR_PROOF_1)).build())
                     .build();
     // Client Block Certificates
     private static final com.concordium.sdk.responses.blockcertificates.BlockCertificates CLIENT_BLOCK_CERT_WITH_QUORUM =