nwaku/waku/waku_rln_relay/conversion_utils.nim

131 lines
4.2 KiB
Nim

{.push raises: [].}
import
std/[sequtils, strutils, algorithm],
web3,
chronicles,
stew/[arrayops, endians2],
stint
import ./constants, ./protocol_types
import ../waku_keystore
export web3, chronicles, stint, constants, endians2
logScope:
topics = "waku rln_relay conversion_utils"
proc inHex*(
value:
IdentityTrapdoor or IdentityNullifier or IdentitySecretHash or IDCommitment or
MerkleNode or Nullifier or Epoch or RlnIdentifier
): string =
var valueHex = "" #UInt256.fromBytesLE(value)
for b in value.reversed():
valueHex = valueHex & b.toHex()
# We pad leading zeroes
while valueHex.len < value.len * 2:
valueHex = "0" & valueHex
return toLowerAscii(valueHex)
proc toUserMessageLimit*(v: UInt256): UserMessageLimit =
return cast[UserMessageLimit](v)
proc encodeLengthPrefix*(input: openArray[byte]): seq[byte] =
## returns length prefixed version of the input
## with the following format [len<8>|input<var>]
## len: 8-byte value that represents the number of bytes in the `input`
## len is serialized in little-endian
## input: the supplied `input`
let
# the length should be serialized in little-endian
len = toBytes(uint64(input.len), Endianness.littleEndian)
output = concat(@len, @input)
return output
proc serialize*(v: uint64): array[32, byte] =
## a private proc to convert uint64 to a byte seq
## this conversion is used in the proofGen proc
## converts `v` to a byte seq in little-endian order
let bytes = toBytes(v, Endianness.littleEndian)
var output: array[32, byte]
discard output.copyFrom(bytes)
return output
proc serialize*(
idSecretHash: IdentitySecretHash,
memIndex: MembershipIndex,
userMessageLimit: UserMessageLimit,
messageId: MessageId,
externalNullifier: ExternalNullifier,
msg: openArray[byte],
): seq[byte] =
## a private proc to convert RateLimitProof and the data to a byte seq
## this conversion is used in the proofGen proc
## the serialization is done as instructed in https://github.com/kilic/rln/blob/7ac74183f8b69b399e3bc96c1ae8ab61c026dc43/src/public.rs#L146
## [ id_key<32> | id_index<8> | epoch<32> | signal_len<8> | signal<var> ]
let memIndexBytes = toBytes(uint64(memIndex), Endianness.littleEndian)
let userMessageLimitBytes = userMessageLimit.serialize()
let messageIdBytes = messageId.serialize()
let lenPrefMsg = encodeLengthPrefix(msg)
let output = concat(
@idSecretHash,
@memIndexBytes,
@userMessageLimitBytes,
@messageIdBytes,
@externalNullifier,
lenPrefMsg,
)
return output
proc serialize*(proof: RateLimitProof, data: openArray[byte]): seq[byte] =
## a private proc to convert RateLimitProof and data to a byte seq
## this conversion is used in the proof verification proc
## [ proof<128> | root<32> | epoch<32> | share_x<32> | share_y<32> | nullifier<32> | rln_identifier<32> | signal_len<8> | signal<var> ]
let lenPrefMsg = encodeLengthPrefix(@data)
var proofBytes = concat(
@(proof.proof),
@(proof.merkleRoot),
@(proof.externalNullifier),
@(proof.shareX),
@(proof.shareY),
@(proof.nullifier),
lenPrefMsg,
)
return proofBytes
# Serializes a sequence of MerkleNodes
proc serialize*(roots: seq[MerkleNode]): seq[byte] =
var rootsBytes: seq[byte] = @[]
for root in roots:
rootsBytes = concat(rootsBytes, @root)
return rootsBytes
# Serializes a sequence of MembershipIndex's
proc serialize*(memIndices: seq[MembershipIndex]): seq[byte] =
var memIndicesBytes = newSeq[byte]()
# serialize the memIndices, with its length prefixed
let len = toBytes(uint64(memIndices.len), Endianness.littleEndian)
memIndicesBytes.add(len)
for memIndex in memIndices:
let memIndexBytes = toBytes(uint64(memIndex), Endianness.littleEndian)
memIndicesBytes = concat(memIndicesBytes, @memIndexBytes)
return memIndicesBytes
proc toEpoch*(t: uint64): Epoch =
## converts `t` to `Epoch` in little-endian order
let bytes = toBytes(t, Endianness.littleEndian)
trace "epoch bytes", bytes = bytes
var epoch: Epoch
discard epoch.copyFrom(bytes)
return epoch
proc fromEpoch*(epoch: Epoch): uint64 =
## decodes bytes of `epoch` (in little-endian) to uint64
let t = fromBytesLE(uint64, array[32, byte](epoch))
return t