nwaku/waku/waku_rln_relay/rln_relay.nim

423 lines
16 KiB
Nim

when (NimMajor, NimMinor) < (1, 4):
{.push raises: [Defect].}
else:
{.push raises: [].}
import
std/[algorithm, sequtils, strutils, tables, times, os, deques],
chronicles, options, chronos, chronos/ratelimit, stint,
web3, json,
web3/ethtypes,
eth/keys,
libp2p/protocols/pubsub/rpc/messages,
libp2p/protocols/pubsub/pubsub,
stew/results,
stew/[byteutils, arrayops]
import
./group_manager,
./rln,
./conversion_utils,
./constants,
./protocol_types,
./protocol_metrics
import
../waku_relay, # for WakuRelayHandler
../waku_core,
../waku_keystore,
../utils/collector
logScope:
topics = "waku rln_relay"
type WakuRlnConfig* = object
rlnRelayDynamic*: bool
rlnRelayCredIndex*: Option[uint]
rlnRelayEthContractAddress*: string
rlnRelayEthClientAddress*: string
rlnRelayCredPath*: string
rlnRelayCredPassword*: string
rlnRelayTreePath*: string
proc createMembershipList*(rln: ptr RLN, n: int): RlnRelayResult[(
seq[RawMembershipCredentials], string
)] =
## createMembershipList produces a sequence of identity credentials in the form of (identity trapdoor, identity nullifier, identity secret hash, id commitment) in the hexadecimal format
## this proc also returns the root of a Merkle tree constructed out of the identity commitment keys of the generated list
## the output of this proc is used to initialize a static group keys (to test waku-rln-relay in the off-chain mode)
## Returns an error if it cannot create the membership list
var output = newSeq[RawMembershipCredentials]()
var idCommitments = newSeq[IDCommitment]()
for i in 0..n-1:
# generate an identity credential
let idCredentialRes = rln.membershipKeyGen()
if idCredentialRes.isErr():
return err("could not generate an identity credential: " & idCredentialRes.error())
let idCredential = idCredentialRes.get()
let idTuple = (idCredential.idTrapdoor.inHex(), idCredential.idNullifier.inHex(), idCredential.idSecretHash.inHex(), idCredential.idCommitment.inHex())
output.add(idTuple)
idCommitments.add(idCredential.idCommitment)
# Insert members into tree
let membersAdded = rln.insertMembers(0, idCommitments)
if not membersAdded:
return err("could not insert members into the tree")
let root = rln.getMerkleRoot().value().inHex()
return ok((output, root))
proc calcEpoch*(t: float64): Epoch =
## gets time `t` as `flaot64` with subseconds resolution in the fractional part
## and returns its corresponding rln `Epoch` value
let e = uint64(t/EpochUnitSeconds)
return toEpoch(e)
type WakuRLNRelay* = ref object of RootObj
# the log of nullifiers and Shamir shares of the past messages grouped per epoch
nullifierLog*: OrderedTable[Epoch, seq[ProofMetadata]]
lastEpoch*: Epoch # the epoch of the last published rln message
groupManager*: GroupManager
method stop*(rlnPeer: WakuRLNRelay) {.async: (raises: [Exception]).} =
## stops the rln-relay protocol
## Throws an error if it cannot stop the rln-relay protocol
# stop the group sync, and flush data to tree db
info "stopping rln-relay"
await rlnPeer.groupManager.stop()
proc hasDuplicate*(rlnPeer: WakuRLNRelay,
proofMetadata: ProofMetadata): RlnRelayResult[bool] =
## returns true if there is another message in the `nullifierLog` of the `rlnPeer` with the same
## epoch and nullifier as `proofMetadata`'s epoch and nullifier
## otherwise, returns false
## Returns an error if it cannot check for duplicates
let externalNullifier = proofMetadata.externalNullifier
# check if the epoch exists
if not rlnPeer.nullifierLog.hasKey(externalNullifier):
return ok(false)
try:
if rlnPeer.nullifierLog[externalNullifier].contains(proofMetadata):
# there is an identical record, mark it as spam
return ok(true)
# check for a message with the same nullifier but different secret shares
let matched = rlnPeer.nullifierLog[externalNullifier].filterIt((
it.nullifier == proofMetadata.nullifier) and ((it.shareX != proofMetadata.shareX) or
(it.shareY != proofMetadata.shareY)))
if matched.len != 0:
# there is a duplicate
return ok(true)
# there is no duplicate
return ok(false)
except KeyError as e:
return err("the epoch was not found")
proc updateLog*(rlnPeer: WakuRLNRelay,
proofMetadata: ProofMetadata): RlnRelayResult[void] =
## saves supplied proofMetadata `proofMetadata`
## in the `nullifierLog` of the `rlnPeer`
## Returns an error if it cannot update the log
let externalNullifier = proofMetadata.externalNullifier
# check if the externalNullifier exists
if not rlnPeer.nullifierLog.hasKey(externalNullifier):
rlnPeer.nullifierLog[externalNullifier] = @[proofMetadata]
return ok()
try:
# check if an identical record exists
if rlnPeer.nullifierLog[externalNullifier].contains(proofMetadata):
# TODO: slashing logic
return ok()
# add proofMetadata to the log
rlnPeer.nullifierLog[externalNullifier].add(proofMetadata)
return ok()
except KeyError as e:
return err("the external nullifier was not found") # should never happen
proc getCurrentEpoch*(): Epoch =
## gets the current rln Epoch time
return calcEpoch(epochTime())
proc absDiff*(e1, e2: Epoch): uint64 =
## returns the absolute difference between the two rln `Epoch`s `e1` and `e2`
## i.e., e1 - e2
# convert epochs to their corresponding unsigned numerical values
let
epoch1 = fromEpoch(e1)
epoch2 = fromEpoch(e2)
# Manually perform an `abs` calculation
if epoch1 > epoch2:
return epoch1 - epoch2
else:
return epoch2 - epoch1
proc validateMessage*(rlnPeer: WakuRLNRelay,
msg: WakuMessage,
timeOption = none(float64)): MessageValidationResult =
## validate the supplied `msg` based on the waku-rln-relay routing protocol i.e.,
## the `msg`'s epoch is within MaxEpochGap of the current epoch
## the `msg` has valid rate limit proof
## the `msg` does not violate the rate limit
## `timeOption` indicates Unix epoch time (fractional part holds sub-seconds)
## if `timeOption` is supplied, then the current epoch is calculated based on that
let decodeRes = RateLimitProof.init(msg.proof)
if decodeRes.isErr():
return MessageValidationResult.Invalid
let proof = decodeRes.get()
# track message count for metrics
waku_rln_messages_total.inc()
# checks if the `msg`'s epoch is far from the current epoch
# it corresponds to the validation of rln external nullifier
var epoch: Epoch
if timeOption.isSome():
epoch = calcEpoch(timeOption.get())
else:
# get current rln epoch
epoch = getCurrentEpoch()
let
msgEpoch = proof.epoch
# calculate the gaps
gap = absDiff(epoch, msgEpoch)
trace "epoch info", currentEpoch = fromEpoch(epoch), msgEpoch = fromEpoch(msgEpoch)
# validate the epoch
if gap > MaxEpochGap:
# message's epoch is too old or too ahead
# accept messages whose epoch is within +-MaxEpochGap from the current epoch
warn "invalid message: epoch gap exceeds a threshold", gap = gap,
payloadLen = msg.payload.len, msgEpoch = fromEpoch(proof.epoch)
waku_rln_invalid_messages_total.inc(labelValues=["invalid_epoch"])
return MessageValidationResult.Invalid
let rootValidationRes = rlnPeer.groupManager.validateRoot(proof.merkleRoot)
if not rootValidationRes:
warn "invalid message: provided root does not belong to acceptable window of roots", provided=proof.merkleRoot.inHex(), validRoots=rlnPeer.groupManager.validRoots.mapIt(it.inHex())
waku_rln_invalid_messages_total.inc(labelValues=["invalid_root"])
return MessageValidationResult.Invalid
# verify the proof
let
contentTopicBytes = msg.contentTopic.toBytes
input = concat(msg.payload, contentTopicBytes)
waku_rln_proof_verification_total.inc()
waku_rln_proof_verification_duration_seconds.nanosecondTime:
let proofVerificationRes = rlnPeer.groupManager.verifyProof(input, proof)
if proofVerificationRes.isErr():
waku_rln_errors_total.inc(labelValues=["proof_verification"])
warn "invalid message: proof verification failed", payloadLen = msg.payload.len
return MessageValidationResult.Invalid
if not proofVerificationRes.value():
# invalid proof
warn "invalid message: invalid proof", payloadLen = msg.payload.len
waku_rln_invalid_messages_total.inc(labelValues=["invalid_proof"])
return MessageValidationResult.Invalid
# check if double messaging has happened
let proofMetadataRes = proof.extractMetadata()
if proofMetadataRes.isErr():
waku_rln_errors_total.inc(labelValues=["proof_metadata_extraction"])
return MessageValidationResult.Invalid
let hasDup = rlnPeer.hasDuplicate(proofMetadataRes.get())
if hasDup.isErr():
waku_rln_errors_total.inc(labelValues=["duplicate_check"])
elif hasDup.value == true:
trace "invalid message: message is spam", payloadLen = msg.payload.len
waku_rln_spam_messages_total.inc()
return MessageValidationResult.Spam
trace "message is valid", payloadLen = msg.payload.len
let rootIndex = rlnPeer.groupManager.indexOfRoot(proof.merkleRoot)
waku_rln_valid_messages_total.observe(rootIndex.toFloat())
return MessageValidationResult.Valid
proc validateMessageAndUpdateLog*(
rlnPeer: WakuRLNRelay,
msg: WakuMessage,
timeOption = none(float64)): MessageValidationResult =
## validates the message and updates the log to prevent double messaging
## in future messages
let result = rlnPeer.validateMessage(msg, timeOption)
let decodeRes = RateLimitProof.init(msg.proof)
if decodeRes.isErr():
return MessageValidationResult.Invalid
let msgProof = decodeRes.get()
let proofMetadataRes = msgProof.extractMetadata()
if proofMetadataRes.isErr():
return MessageValidationResult.Invalid
# insert the message to the log (never errors)
discard rlnPeer.updateLog(proofMetadataRes.get())
return result
proc toRLNSignal*(wakumessage: WakuMessage): seq[byte] =
## it is a utility proc that prepares the `data` parameter of the proof generation procedure i.e., `proofGen` that resides in the current module
## it extracts the `contentTopic` and the `payload` of the supplied `wakumessage` and serializes them into a byte sequence
let
contentTopicBytes = wakumessage.contentTopic.toBytes()
output = concat(wakumessage.payload, contentTopicBytes)
return output
proc appendRLNProof*(rlnPeer: WakuRLNRelay,
msg: var WakuMessage,
senderEpochTime: float64): bool =
## returns true if it can create and append a `RateLimitProof` to the supplied `msg`
## returns false otherwise
## `senderEpochTime` indicates the number of seconds passed since Unix epoch. The fractional part holds sub-seconds.
## The `epoch` field of `RateLimitProof` is derived from the provided `senderEpochTime` (using `calcEpoch()`)
let input = msg.toRLNSignal()
let epoch = calcEpoch(senderEpochTime)
let proofGenRes = rlnPeer.groupManager.generateProof(input, epoch)
if proofGenRes.isErr():
return false
msg.proof = proofGenRes.get().encode().buffer
return true
proc clearNullifierLog(rlnPeer: WakuRlnRelay) =
# clear the first MaxEpochGap epochs of the nullifer log
# if more than MaxEpochGap epochs are in the log
# note: the epochs are ordered ascendingly
if rlnPeer.nullifierLog.len().uint < MaxEpochGap:
return
trace "clearing epochs from the nullifier log", count = MaxEpochGap
let epochsToClear = rlnPeer.nullifierLog.keys().toSeq()[0..<MaxEpochGap]
for epoch in epochsToClear:
rlnPeer.nullifierLog.del(epoch)
proc generateRlnValidator*(wakuRlnRelay: WakuRLNRelay,
spamHandler = none(SpamHandler)): WakuValidatorHandler =
## this procedure is a thin wrapper for the pubsub addValidator method
## it sets a validator for waku messages, acting in the registered pubsub topic
## the message validation logic is according to https://rfc.vac.dev/spec/17/
proc validator(topic: string, message: WakuMessage): Future[pubsub.ValidationResult] {.async.} =
trace "rln-relay topic validator is called"
wakuRlnRelay.clearNullifierLog()
let decodeRes = RateLimitProof.init(message.proof)
if decodeRes.isErr():
trace "generateRlnValidator reject", error=decodeRes.error
return pubsub.ValidationResult.Reject
let msgProof = decodeRes.get()
# validate the message and update log
let validationRes = wakuRlnRelay.validateMessageAndUpdateLog(message)
let
proof = toHex(msgProof.proof)
epoch = fromEpoch(msgProof.epoch)
root = inHex(msgProof.merkleRoot)
shareX = inHex(msgProof.shareX)
shareY = inHex(msgProof.shareY)
nullifier = inHex(msgProof.nullifier)
payload = string.fromBytes(message.payload)
case validationRes:
of Valid:
trace "message validity is verified, relaying:", proof=proof, root=root, shareX=shareX, shareY=shareY, nullifier=nullifier
return pubsub.ValidationResult.Accept
of Invalid:
trace "message validity could not be verified, discarding:", proof=proof, root=root, shareX=shareX, shareY=shareY, nullifier=nullifier
return pubsub.ValidationResult.Reject
of Spam:
trace "A spam message is found! yay! discarding:", proof=proof, root=root, shareX=shareX, shareY=shareY, nullifier=nullifier
if spamHandler.isSome():
let handler = spamHandler.get()
handler(message)
return pubsub.ValidationResult.Reject
return validator
proc mount(conf: WakuRlnConfig,
registrationHandler = none(RegistrationHandler)
): Future[WakuRlnRelay] {.async: (raises: [Exception]).} =
var
groupManager: GroupManager
# create an RLN instance
let rlnInstanceRes = createRLNInstance(tree_path = conf.rlnRelayTreePath)
if rlnInstanceRes.isErr():
raise newException(CatchableError, "RLN instance creation failed")
let rlnInstance = rlnInstanceRes.get()
if not conf.rlnRelayDynamic:
# static setup
let parsedGroupKeysRes = StaticGroupKeys.toIdentityCredentials()
if parsedGroupKeysRes.isErr():
raise newException(ValueError, "Static group keys are not valid")
groupManager = StaticGroupManager(groupSize: StaticGroupSize,
groupKeys: parsedGroupKeysRes.get(),
membershipIndex: conf.rlnRelayCredIndex,
rlnInstance: rlnInstance)
# we don't persist credentials in static mode since they exist in ./constants.nim
else:
# dynamic setup
proc useValueOrNone(s: string): Option[string] =
if s == "": none(string) else: some(s)
let
rlnRelayCredPath = useValueOrNone(conf.rlnRelayCredPath)
rlnRelayCredPassword = useValueOrNone(conf.rlnRelayCredPassword)
groupManager = OnchainGroupManager(ethClientUrl: conf.rlnRelayEthClientAddress,
ethContractAddress: $conf.rlnRelayEthContractAddress,
rlnInstance: rlnInstance,
registrationHandler: registrationHandler,
keystorePath: rlnRelayCredPath,
keystorePassword: rlnRelayCredPassword,
membershipIndex: conf.rlnRelayCredIndex)
# Initialize the groupManager
await groupManager.init()
# Start the group sync
await groupManager.startGroupSync()
return WakuRLNRelay(groupManager: groupManager)
proc isReady*(rlnPeer: WakuRLNRelay): Future[bool] {.async: (raises: [Exception]).} =
## returns true if the rln-relay protocol is ready to relay messages
## returns false otherwise
# could be nil during startup
if rlnPeer.groupManager == nil:
return false
try:
return await rlnPeer.groupManager.isReady()
except CatchableError:
error "could not check if the rln-relay protocol is ready", err = getCurrentExceptionMsg()
return false
proc new*(T: type WakuRlnRelay,
conf: WakuRlnConfig,
registrationHandler = none(RegistrationHandler)
): Future[RlnRelayResult[WakuRlnRelay]] {.async.} =
## Mounts the rln-relay protocol on the node.
## The rln-relay protocol can be mounted in two modes: on-chain and off-chain.
## Returns an error if the rln-relay protocol could not be mounted.
try:
let rlnRelay = await mount(conf, registrationHandler)
return ok(rlnRelay)
except:
return err("exception in new WakuRlnRelay: " & getCurrentExceptionMsg())