nwaku/waku/v2/waku_rln_relay/conversion_utils.nim

119 lines
3.9 KiB
Nim

when (NimMajor, NimMinor) < (1, 4):
{.push raises: [Defect].}
else:
{.push raises: [].}
import
std/[sequtils, strutils, algorithm],
web3,
chronicles,
stew/[arrayops, results, 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 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*(idSecretHash: IdentitySecretHash,
memIndex: MembershipIndex,
epoch: Epoch,
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 lenPrefMsg = encodeLengthPrefix(msg)
let output = concat(@idSecretHash, @memIndexBytes, @epoch, 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.epoch),
@(proof.shareX),
@(proof.shareY),
@(proof.nullifier),
@(proof.rlnIdentifier),
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)
debug "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