nwaku/tests/v2/test_waku_rln_relay.nim

{.used.}

import
  std/options, sequtils, times,
  testutils/unittests, chronos, chronicles, stint,
  stew/byteutils, stew/shims/net as stewNet,
  libp2p/crypto/crypto,
  ../../waku/v2/protocol/waku_rln_relay/[rln, waku_rln_relay_utils,
      waku_rln_relay_types],
  ../../waku/v2/node/wakunode2,
  ../test_helpers

const RLNRELAY_PUBSUB_TOPIC = "waku/2/rlnrelay/proto"
const RLNRELAY_CONTENT_TOPIC = "waku/2/rlnrelay/proto"

procSuite "Waku rln relay":
  asyncTest "mount waku-rln-relay in the off-chain mode":
    let
      nodeKey = crypto.PrivateKey.random(Secp256k1, rng[])[]
      node = WakuNode.new(nodeKey, ValidIpAddress.init("0.0.0.0"),
        Port(60000))
    await node.start()

    # preparing inputs to mount rln-relay

    # create a group of 100 membership keys
    let
      (groupKeys, root) = createMembershipList(100)
    check:
       groupKeys.len == 100
    let
      # convert the keys to MembershipKeyPair structs
      groupKeyPairs = groupKeys.toMembershipKeyPairs()
      # extract the id commitments
      groupIDCommitments = groupKeyPairs.mapIt(it.idCommitment)
    debug "groupKeyPairs", groupKeyPairs
    debug "groupIDCommitments", groupIDCommitments

    # index indicates the position of a membership key pair in the static list of group keys i.e., groupKeyPairs
    # the corresponding key pair will be used to mount rlnRelay on the current node
    # index also represents the index of the leaf in the Merkle tree that contains node's commitment key
    let index = MembershipIndex(5)

    # -------- mount rln-relay in the off-chain mode
    node.mountRelay(@[RLNRELAY_PUBSUB_TOPIC])
    node.mountRlnRelayStatic(group = groupIDCommitments,
                            memKeyPair = groupKeyPairs[index],
                            memIndex = index,
                            pubsubTopic = RLNRELAY_PUBSUB_TOPIC,
                            contentTopic = RLNRELAY_CONTENT_TOPIC)

    # get the root of Merkle tree which is constructed inside the mountRlnRelay proc
    let calculatedRoot = node.wakuRlnRelay.rlnInstance.getMerkleRoot().value().toHex
    debug "calculated root by mountRlnRelay", calculatedRoot

    # this part checks whether the Merkle tree is constructed correctly inside the mountRlnRelay proc
    # this check is done by comparing the tree root resulted from mountRlnRelay i.e., calculatedRoot
    # against the root which is the expected root
    check:
      calculatedRoot == root

    await node.stop()

suite "Waku rln relay":
  test "key_gen Nim Wrappers":
    var
      merkleDepth: csize_t = 32
      # parameters.key contains the parameters related to the Poseidon hasher
      # to generate this file, clone this repo https://github.com/kilic/rln
      # and run the following command in the root directory of the cloned project
      # cargo run --example export_test_keys
      # the file is generated separately and copied here
      parameters = readFile("waku/v2/protocol/waku_rln_relay/parameters.key")
      pbytes = parameters.toBytes()
      len: csize_t = uint(pbytes.len)
      parametersBuffer = Buffer(`ptr`: addr(pbytes[0]), len: len)
    check:
      # check the parameters.key is not empty
      pbytes.len != 0

    var
      rlnInstance: RLN[Bn256]
    let res = new_circuit_from_params(merkleDepth, addr parametersBuffer,
        addr rlnInstance)
    check:
      # check whether the circuit parameters are generated successfully
      res == true

    # keysBufferPtr will hold the generated key pairs i.e., secret and public keys
    var
      keysBuffer: Buffer
      keysBufferPtr = addr(keysBuffer)
      done = key_gen(rlnInstance, keysBufferPtr)
    check:
      # check whether the keys are generated successfully
      done == true

    if done:
      var generatedKeys = cast[ptr array[64, byte]](keysBufferPtr.`ptr`)[]
      check:
        # the public and secret keys together are 64 bytes
        generatedKeys.len == 64
      debug "generated keys: ", generatedKeys

  test "membership Key Gen":
    # create an RLN instance
    var rlnInstance = createRLNInstance()
    check:
      rlnInstance.isOk == true

    var key = membershipKeyGen(rlnInstance.value)
    var empty: array[32, byte]
    check:
      key.isSome
      key.get().idKey.len == 32
      key.get().idCommitment.len == 32
      key.get().idKey != empty
      key.get().idCommitment != empty

    debug "the generated membership key pair: ", key

  test "get_root Nim binding":
    # create an RLN instance which also includes an empty Merkle tree
    var rlnInstance = createRLNInstance()
    check:
      rlnInstance.isOk == true

    # read the Merkle Tree root
    var
      root1 {.noinit.}: Buffer = Buffer()
      rootPtr1 = addr(root1)
      get_root_successful1 = get_root(rlnInstance.value, rootPtr1)
    check:
      get_root_successful1
      root1.len == 32

    # read the Merkle Tree root
    var
      root2 {.noinit.}: Buffer = Buffer()
      rootPtr2 = addr(root2)
      get_root_successful2 = get_root(rlnInstance.value, rootPtr2)
    check:
      get_root_successful2
      root2.len == 32

    var rootValue1 = cast[ptr array[32, byte]] (root1.`ptr`)
    let rootHex1 = rootValue1[].toHex

    var rootValue2 = cast[ptr array[32, byte]] (root2.`ptr`)
    let rootHex2 = rootValue2[].toHex

    # the two roots must be identical
    check:
      rootHex1 == rootHex2
  test "getMerkleRoot utils":
    # create an RLN instance which also includes an empty Merkle tree
    var rlnInstance = createRLNInstance()
    check:
      rlnInstance.isOk == true

    # read the Merkle Tree root
    var root1 = getMerkleRoot(rlnInstance.value())
    check:
      root1.isOk
    let rootHex1 = root1.value().toHex

    # read the Merkle Tree root
    var root2 = getMerkleRoot(rlnInstance.value())
    check:
      root2.isOk
    let rootHex2 = root2.value().toHex

    # the two roots must be identical
    check:
      rootHex1 == rootHex2

  test "update_next_member Nim Wrapper":
    # create an RLN instance which also includes an empty Merkle tree
    var rlnInstance = createRLNInstance()
    check:
      rlnInstance.isOk == true

    # generate a key pair
    var keypair = membershipKeyGen(rlnInstance.value)
    check:
      keypair.isSome()
    var pkBuffer = toBuffer(keypair.get().idCommitment)
    let pkBufferPtr = addr pkBuffer

    # add the member to the tree
    var member_is_added = update_next_member(rlnInstance.value, pkBufferPtr)
    check:
      member_is_added == true

  test "delete_member Nim wrapper":
    # create an RLN instance which also includes an empty Merkle tree
    var rlnInstance = createRLNInstance()
    check:
      rlnInstance.isOk == true

    # delete the first member
    var deleted_member_index = MembershipIndex(0)
    let deletion_success = delete_member(rlnInstance.value, deleted_member_index)
    check:
      deletion_success

  test "insertMember rln utils":
    # create an RLN instance which also includes an empty Merkle tree
    var rlnInstance = createRLNInstance()
    check:
      rlnInstance.isOk == true
    var rln = rlnInstance.value
    # generate a key pair
    var keypair = rln.membershipKeyGen()
    check:
      keypair.isSome()
    check:
      rln.insertMember(keypair.get().idCommitment)

  test "removeMember rln utils":
    # create an RLN instance which also includes an empty Merkle tree
    var rlnInstance = createRLNInstance()
    check:
      rlnInstance.isOk == true
    var rln = rlnInstance.value
    check:
      rln.removeMember(MembershipIndex(0))

  test "Merkle tree consistency check between deletion and insertion":
    # create an RLN instance
    var rlnInstance = createRLNInstance()
    check:
      rlnInstance.isOk == true

    # read the Merkle Tree root
    var
      root1 {.noinit.}: Buffer = Buffer()
      rootPtr1 = addr(root1)
      get_root_successful1 = get_root(rlnInstance.value, rootPtr1)
    check:
      get_root_successful1
      root1.len == 32

    # generate a key pair
    var keypair = membershipKeyGen(rlnInstance.value)
    check: keypair.isSome()
    var pkBuffer = toBuffer(keypair.get().idCommitment)
    let pkBufferPtr = addr pkBuffer

    # add the member to the tree
    var member_is_added = update_next_member(rlnInstance.value, pkBufferPtr)
    check:
      member_is_added

    # read the Merkle Tree root after insertion
    var
      root2 {.noinit.}: Buffer = Buffer()
      rootPtr2 = addr(root2)
      get_root_successful2 = get_root(rlnInstance.value, rootPtr2)
    check:
      get_root_successful2
      root2.len == 32

    # delete the first member
    var deleted_member_index = MembershipIndex(0)
    let deletion_success = delete_member(rlnInstance.value, deleted_member_index)
    check:
      deletion_success

    # read the Merkle Tree root after the deletion
    var
      root3 {.noinit.}: Buffer = Buffer()
      rootPtr3 = addr(root3)
      get_root_successful3 = get_root(rlnInstance.value, rootPtr3)
    check:
      get_root_successful3
      root3.len == 32

    var rootValue1 = cast[ptr array[32, byte]] (root1.`ptr`)
    let rootHex1 = rootValue1[].toHex
    debug "The initial root", rootHex1

    var rootValue2 = cast[ptr array[32, byte]] (root2.`ptr`)
    let rootHex2 = rootValue2[].toHex
    debug "The root after insertion", rootHex2

    var rootValue3 = cast[ptr array[32, byte]] (root3.`ptr`)
    let rootHex3 = rootValue3[].toHex
    debug "The root after deletion", rootHex3

    # the root must change after the insertion
    check: not(rootHex1 == rootHex2)

    ## The initial root of the tree (empty tree) must be identical to
    ## the root of the tree after one insertion followed by a deletion
    check:
      rootHex1 == rootHex3
  test "Merkle tree consistency check between deletion and insertion using rln utils":
    # create an RLN instance
    var rlnInstance = createRLNInstance()
    check:
      rlnInstance.isOk == true
    var rln = rlnInstance.value()

    # read the Merkle Tree root
    var root1 = rln.getMerkleRoot()
    check:
      root1.isOk
    let rootHex1 = root1.value().toHex()

    # generate a key pair
    var keypair = rln.membershipKeyGen()
    check:
      keypair.isSome()
    let member_inserted = rln.insertMember(keypair.get().idCommitment)
    check:
      member_inserted

    # read the Merkle Tree root after insertion
    var root2 = rln.getMerkleRoot()
    check:
      root2.isOk
    let rootHex2 = root2.value().toHex()


    # delete the first member
    var deleted_member_index = MembershipIndex(0)
    let deletion_success = rln.removeMember(deleted_member_index)
    check:
      deletion_success

    # read the Merkle Tree root after the deletion
    var root3 = rln.getMerkleRoot()
    check:
      root3.isOk
    let rootHex3 = root3.value().toHex()


    debug "The initial root", rootHex1
    debug "The root after insertion", rootHex2
    debug "The root after deletion", rootHex3

    # the root must change after the insertion
    check:
      not(rootHex1 == rootHex2)

    ## The initial root of the tree (empty tree) must be identical to
    ## the root of the tree after one insertion followed by a deletion
    check:
      rootHex1 == rootHex3

  test "hash Nim Wrappers":
    # create an RLN instance
    var rlnInstance = createRLNInstance()
    check:
      rlnInstance.isOk == true

    # prepare the input
    var
      msg = "Hello".toBytes()
      hashInput = appendLength(msg)
      hashInputBuffer = toBuffer(hashInput)

    # prepare other inputs to the hash function
    var outputBuffer: Buffer

    let hashSuccess = hash(rlnInstance.value, addr hashInputBuffer,
        addr outputBuffer)
    check:
      hashSuccess
    let outputArr = cast[ptr array[32, byte]](outputBuffer.`ptr`)[]
    check:
      "efb8ac39dc22eaf377fe85b405b99ba78dbc2f3f32494add4501741df946bd1d" ==
          outputArr.toHex()

    var
      hashOutput = cast[ptr array[32, byte]] (outputBuffer.`ptr`)[]
      hashOutputHex = hashOutput.toHex()

    debug "hash output", hashOutputHex

  test "hash utils":
    # create an RLN instance
    var rlnInstance = createRLNInstance()
    check:
      rlnInstance.isOk == true
    let rln = rlnInstance.value

    # prepare the input
    let msg = "Hello".toBytes()

    let hash = rln.hash(msg)
    check:
      "efb8ac39dc22eaf377fe85b405b99ba78dbc2f3f32494add4501741df946bd1d" ==
          hash.toHex()

  test "create a list of membership keys and construct a Merkle tree based on the list":
    let
      groupSize = 100
      (list, root) = createMembershipList(groupSize)

    debug "created membership key list", list
    debug "the Merkle tree root", root

    check:
      list.len == groupSize # check the number of keys
      root.len == HASH_HEX_SIZE # check the size of the calculated tree root

  test "check correctness of toMembershipKeyPairs and calcMerkleRoot":
    let groupKeys = STATIC_GROUP_KEYS

    # create a set of MembershipKeyPair objects from groupKeys
    let groupKeyPairs = groupKeys.toMembershipKeyPairs()
    # extract the id commitments
    let groupIDCommitments = groupKeyPairs.mapIt(it.idCommitment)
    # calculate the Merkle tree root out of the extracted id commitments
    let root = calcMerkleRoot(groupIDCommitments)

    debug "groupKeyPairs", groupKeyPairs
    debug "groupIDCommitments", groupIDCommitments
    debug "root", root

    check:
      # check that the correct number of key pairs is created
      groupKeyPairs.len == StaticGroupSize
      # compare the calculated root against the correct root
      root == STATIC_GROUP_MERKLE_ROOT

  test "RateLimitProof Protobuf encode/init test":
    var
      proof: ZKSNARK
      merkleRoot: MerkleNode
      epoch: Epoch
      shareX: MerkleNode
      shareY: MerkleNode
      nullifier: Nullifier
    # populate fields with dummy values
    for x in proof.mitems: x = 1
    for x in merkleRoot.mitems: x = 2
    for x in epoch.mitems: x = 3
    for x in shareX.mitems: x = 4
    for x in shareY.mitems: x = 5
    for x in nullifier.mitems: x = 6

    let
      rateLimitProof = RateLimitProof(proof: proof,
                          merkleRoot: merkleRoot,
                          epoch: epoch,
                          shareX: shareX,
                          shareY: shareY,
                          nullifier: nullifier)
      protobuf = rateLimitProof.encode()
      decodednsp = RateLimitProof.init(protobuf.buffer)

    check:
      decodednsp.isErr == false
      decodednsp.value == rateLimitProof

  test "test proofVerify and proofGen for a valid proof":
    var rlnInstance = createRLNInstance()
    check:
      rlnInstance.isOk
    var rln = rlnInstance.value

    let
      # create a membership key pair
      memKeys = membershipKeyGen(rln).get()
      # peer's index in the Merkle Tree
      index = 5

    # Create a Merkle tree with random members
    for i in 0..10:
      var member_is_added: bool = false
      if (i == index):
        # insert the current peer's pk
        member_is_added = rln.insertMember(memKeys.idCommitment)
      else:
        # create a new key pair
        let memberKeys = rln.membershipKeyGen()
        member_is_added = rln.insertMember(memberKeys.get().idCommitment)
      # check the member is added
      check:
        member_is_added

    # prepare the message
    let messageBytes = "Hello".toBytes()

    # prepare the epoch
    var epoch: Epoch
    debug "epoch", epochHex = epoch.toHex()

    # generate proof
    let proofRes = rln.proofGen(data = messageBytes,
                                memKeys = memKeys,
                                memIndex = MembershipIndex(index),
                                epoch = epoch)
    check:
      proofRes.isOk()
    let proof = proofRes.value

    # verify the proof
    let verified = rln.proofVerify(data = messageBytes,
                                    proof = proof)
    check:
      verified == true

  test "test proofVerify and proofGen for an invalid proof":
    var rlnInstance = createRLNInstance()
    check:
      rlnInstance.isOk == true
    var rln = rlnInstance.value

    let
      # create a membership key pair
      memKeys = membershipKeyGen(rln).get()
      # peer's index in the Merkle Tree
      index = 5

    # Create a Merkle tree with random members
    for i in 0..10:
      var member_is_added: bool = false
      if (i == index):
        # insert the current peer's pk
        member_is_added = rln.insertMember(memKeys.idCommitment)
      else:
        # create a new key pair
        let memberKeys = rln.membershipKeyGen()
        member_is_added = rln.insertMember(memberKeys.get().idCommitment)
      # check the member is added
      check:
        member_is_added

    # prepare the message
    let messageBytes = "Hello".toBytes()

    # prepare the epoch
    var epoch: Epoch
    debug "epoch in bytes", epochHex = epoch.toHex()


    let badIndex = 4
    # generate proof
    let proofRes = rln.proofGen(data = messageBytes,
                                memKeys = memKeys,
                                memIndex = MembershipIndex(badIndex),
                                epoch = epoch)
    check:
      proofRes.isOk()
    let proof = proofRes.value

    # verify the proof (should not be verified)
    let verified = rln.proofVerify(data = messageBytes,
                                 proof = proof)
    check:
      verified == false
  test "toEpoch and fromEpoch consistency check":
    # check edge cases
    let
      epoch = uint64.high # rln epoch
      epochBytes = epoch.toEpoch()
      decodedEpoch = epochBytes.fromEpoch()
    check:
      epoch == decodedEpoch
    debug "encoded and decode time", epoch = epoch, epochBytes = epochBytes,
      decodedEpoch = decodedEpoch

  test "Epoch comparison":
    # check edge cases
    let
      time1 = uint64.high
      time2 = uint64.high - 1
      epoch1 = time1.toEpoch()
      epoch2 = time2.toEpoch()
    check:
      diff(epoch1, epoch2) == int64(1)
      diff(epoch2, epoch1) == int64(-1)

  test "updateLog and hasDuplicate tests":
    let
      wakurlnrelay = WakuRLNRelay()
      epoch = getCurrentEpoch()

    #  cretae some dummy nullifiers and secret shares
    var nullifier1: Nullifier
    for index, x in nullifier1.mpairs: nullifier1[index] = 1
    var shareX1: MerkleNode
    for index, x in shareX1.mpairs: shareX1[index] = 1
    let shareY1 = shareX1

    var nullifier2: Nullifier
    for index, x in nullifier2.mpairs: nullifier2[index] = 2
    var shareX2: MerkleNode
    for index, x in shareX2.mpairs: shareX2[index] = 2
    let shareY2 = shareX2

    let nullifier3 = nullifier1
    var shareX3: MerkleNode
    for index, x in shareX3.mpairs: shareX3[index] = 3
    let shareY3 = shareX3

    let
      wm1 = WakuMessage(proof: RateLimitProof(epoch: epoch,
          nullifier: nullifier1, shareX: shareX1, shareY: shareY1))
      wm2 = WakuMessage(proof: RateLimitProof(epoch: epoch,
          nullifier: nullifier2, shareX: shareX2, shareY: shareY2))
      wm3 = WakuMessage(proof: RateLimitProof(epoch: epoch,
          nullifier: nullifier3, shareX: shareX3, shareY: shareY3))

    # check whether hasDuplicate correctly finds records with the same nullifiers but different secret shares
    # no duplicate for wm1 should be found, since the log is empty
    let result1 = wakurlnrelay.hasDuplicate(wm1)
    check:
      result1.isOk
      # no duplicate is found
      result1.value == false
    #  add it to the log
    discard wakurlnrelay.updateLog(wm1)

    # # no duplicate for wm2 should be found, its nullifier differs from wm1
    let result2 = wakurlnrelay.hasDuplicate(wm2)
    check:
      result2.isOk
      # no duplicate is found
      result2.value == false
    #  add it to the log
    discard wakurlnrelay.updateLog(wm2)

    #  wm3 has the same nullifier as wm1 but different secret shares, it should be detected as duplicate
    let result3 = wakurlnrelay.hasDuplicate(wm3)
    check:
      result3.isOk
      # it is a duplicate
      result3.value == true

  test "validateMessage test":
    # setup a wakurlnrelay peer with a static group----------

    # create a group of 100 membership keys
    let
      (groupKeys, root) = createMembershipList(100)
      # convert the keys to MembershipKeyPair structs
      groupKeyPairs = groupKeys.toMembershipKeyPairs()
      # extract the id commitments
      groupIDCommitments = groupKeyPairs.mapIt(it.idCommitment)
    debug "groupKeyPairs", groupKeyPairs
    debug "groupIDCommitments", groupIDCommitments

    # index indicates the position of a membership key pair in the static list of group keys i.e., groupKeyPairs
    # the corresponding key pair will be used to mount rlnRelay on the current node
    # index also represents the index of the leaf in the Merkle tree that contains node's commitment key
    let index = MembershipIndex(5)

    # create an RLN instance
    var rlnInstance = createRLNInstance()
    doAssert(rlnInstance.isOk)
    var rln = rlnInstance.value

    # add members
    discard rln.addAll(groupIDCommitments)

    let
      wakuRlnRelay = WakuRLNRelay(membershipIndex: index,
          membershipKeyPair: groupKeyPairs[index], rlnInstance: rln)

    # get the current epoch time
    let time = epochTime()

    #  create some messages from the same peer and append rln proof to them, except wm4
    var
      wm1 = WakuMessage(payload: "Valid message".toBytes())
      proofAdded1 = wakuRlnRelay.appendRLNProof(wm1, time)
      # another message in the same epoch as wm1, it will break the messaging rate limit
      wm2 = WakuMessage(payload: "Spam".toBytes())
      proofAdded2 = wakuRlnRelay.appendRLNProof(wm2, time)
      #  wm3 points to the next epoch
      wm3 = WakuMessage(payload: "Valid message".toBytes())
      proofAdded3 = wakuRlnRelay.appendRLNProof(wm3, time+EPOCH_UNIT_SECONDS)
      wm4 = WakuMessage(payload: "Invalid message".toBytes())

    # checks proofs are added
    check:
      proofAdded1
      proofAdded2
      proofAdded3

    # validate messages
    # validateMessage proc checks the validity of the message fields and adds it to the log (if valid)
    let
      msgValidate1 = wakuRlnRelay.validateMessage(wm1, some(time))
      # wm2 is published within the same Epoch as wm1 and should be found as spam
      msgValidate2 = wakuRlnRelay.validateMessage(wm2, some(time))
      # a valid message should be validated successfully
      msgValidate3 = wakuRlnRelay.validateMessage(wm3, some(time))
      # wm4 has no rln proof and should not be validated
      msgValidate4 = wakuRlnRelay.validateMessage(wm4, some(time))


    check:
      msgValidate1 == MessageValidationResult.Valid
      msgValidate2 == MessageValidationResult.Spam
      msgValidate3 == MessageValidationResult.Valid
      msgValidate4 == MessageValidationResult.Invalid
  test "toIDCommitment and toUInt256":
    # create an instance of rln
    var rlnInstance = createRLNInstance()
    check:
      rlnInstance.isOk == true
    
    # create a key pair
    var keypair = rlnInstance.value.membershipKeyGen()
    check:
      keypair.isSome()

    # convert the idCommitment to UInt256
    let idCUInt = keypair.get().idCommitment.toUInt256()
    # convert the UInt256 back to ICommitment
    let idCommitment = toIDCommitment(idCUInt)

    # check that the conversion has not distorted the original value
    check:
      keypair.get().idCommitment == idCommitment