improve validation of risc0 verifier info length

Signed-off-by: Jun Kimura <jun.kimura@datachain.jp>

Author: bluele

contracts/LCPClientZKDCAPBase.sol

@@ -279,7 +279,8 @@ abstract contract LCPClientZKDCAPBase is LCPClientBase {
         if (uint8(verifierInfo[0]) != ZKVM_TYPE_RISC_ZERO) {
             revert LCPClientZKDCAPInvalidVerifierInfoZKVMType();
         }
-        if (vlen < 64) {
+        // risc0 verifier info should be 64 bytes
+        if (vlen != 64) {
             revert LCPClientZKDCAPInvalidVerifierInfoLength();
         }
         // 32..64 bytes: image ID

test/LCPClientZKDCAPTest.t.sol

@@ -670,6 +670,7 @@ contract LCPClientZKDCAPTest is BasicTest {
         vm.warp(ZKDCAPTestHelper.TEST_TIMESTAMP);
         bytes memory consensusStateBytes = LCPProtoMarshaler.marshal(defaultConsensusState());
         IbcLightclientsLcpV1ClientState.Data memory clientState = defaultClientState();
+        bytes memory valid_zkdcap_verifier_info = clientState.zkdcap_verifier_infos[0];
         clientState.zkdcap_verifier_infos[0] = new bytes(0);
         bytes memory clientStateBytes = LCPProtoMarshaler.marshal(clientState);
         vm.expectRevert();
@@ -689,6 +690,12 @@ contract LCPClientZKDCAPTest is BasicTest {
         clientStateBytes = LCPProtoMarshaler.marshal(clientState);
         vm.expectRevert();
         lc.initializeClient(clientId, clientStateBytes, consensusStateBytes);
+
+        clientState.zkdcap_verifier_infos = new bytes[](1);
+        clientState.zkdcap_verifier_infos[0] = abi.encodePacked(valid_zkdcap_verifier_info, bytes1(0x0));
+        clientStateBytes = LCPProtoMarshaler.marshal(clientState);
+        vm.expectRevert();
+        lc.initializeClient(clientId, clientStateBytes, consensusStateBytes);
     }
 
     function testInitializeClientInvalidValues() public {