nwaku/waku/v1/node/rpc/hexstrings.nim

223 lines
7.1 KiB
Nim

# Nimbus
# Copyright (c) 2018 Status Research & Development GmbH
# Licensed under either of
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
# * MIT license ([LICENSE-MIT](LICENSE-MIT))
# at your option.
# This file may not be copied, modified, or distributed except according to
# those terms.
## This module implements the Ethereum hexadecimal string formats for JSON
## See: https://github.com/ethereum/wiki/wiki/JSON-RPC#hex-value-encoding
#[
Note:
The following types are converted to hex strings when marshalled to JSON:
* Hash256
* UInt256
* seq[byte]
* openArray[seq]
* PublicKey
* PrivateKey
* SymKey
* Topic
* Bytes
]#
import
stint, stew/byteutils, eth/keys, eth/common/eth_types,
../../protocol/waku_protocol
type
HexDataStr* = distinct string
Identifier* = distinct string # 32 bytes, no 0x prefix!
HexStrings = HexDataStr | Identifier
# Hex validation
template hasHexHeader(value: string): bool =
if value.len >= 2 and value[0] == '0' and value[1] in {'x', 'X'}: true
else: false
template isHexChar(c: char): bool =
if c notin {'0'..'9'} and
c notin {'a'..'f'} and
c notin {'A'..'F'}: false
else: true
func isValidHexQuantity*(value: string): bool =
if not value.hasHexHeader:
return false
# No leading zeros (but allow 0x0)
if value.len < 3 or (value.len > 3 and value[2] == '0'): return false
for i in 2 ..< value.len:
let c = value[i]
if not c.isHexChar:
return false
return true
func isValidHexData*(value: string, header = true): bool =
if header and not value.hasHexHeader:
return false
# Must be even number of digits
if value.len mod 2 != 0: return false
# Leading zeros are allowed
for i in 2 ..< value.len:
let c = value[i]
if not c.isHexChar:
return false
return true
template isValidHexData(value: string, hexLen: int, header = true): bool =
value.len == hexLen and value.isValidHexData(header)
func isValidIdentifier*(value: string): bool =
# 32 bytes for Whisper ID, no 0x prefix
result = value.isValidHexData(64, false)
func isValidPublicKey*(value: string): bool =
# 65 bytes for Public Key plus 1 byte for 0x prefix
result = value.isValidHexData(132)
func isValidPrivateKey*(value: string): bool =
# 32 bytes for Private Key plus 1 byte for 0x prefix
result = value.isValidHexData(66)
func isValidSymKey*(value: string): bool =
# 32 bytes for Private Key plus 1 byte for 0x prefix
result = value.isValidHexData(66)
func isValidHash256*(value: string): bool =
# 32 bytes for Hash256 plus 1 byte for 0x prefix
result = value.isValidHexData(66)
func isValidTopic*(value: string): bool =
# 4 bytes for Topic plus 1 byte for 0x prefix
result = value.isValidHexData(10)
const
SInvalidData = "Invalid hex data format for Ethereum"
proc validateHexData*(value: string) {.inline.} =
if unlikely(not value.isValidHexData):
raise newException(ValueError, SInvalidData & ": " & value)
# Initialisation
proc hexDataStr*(value: string): HexDataStr {.inline.} =
value.validateHexData
result = value.HexDataStr
# Converters for use in RPC
import json
from json_rpc/rpcserver import expect
proc `%`*(value: HexStrings): JsonNode =
result = %(value.string)
# Overloads to support expected representation of hex data
proc `%`*(value: Hash256): JsonNode =
#result = %("0x" & $value) # More clean but no lowercase :(
result = %("0x" & value.data.toHex)
proc `%`*(value: UInt256): JsonNode =
result = %("0x" & value.toString(16))
proc `%`*(value: PublicKey): JsonNode =
result = %("0x04" & $value)
proc `%`*(value: PrivateKey): JsonNode =
result = %("0x" & $value)
proc `%`*(value: SymKey): JsonNode =
result = %("0x" & value.toHex)
proc `%`*(value: waku_protocol.Topic): JsonNode =
result = %("0x" & value.toHex)
proc `%`*(value: seq[byte]): JsonNode =
if value.len > 0:
result = %("0x" & value.toHex)
else:
result = newJArray()
# Helpers for the fromJson procs
proc toPublicKey*(key: string): PublicKey {.inline.} =
result = PublicKey.fromHex(key[4 .. ^1]).tryGet()
proc toPrivateKey*(key: string): PrivateKey {.inline.} =
result = PrivateKey.fromHex(key[2 .. ^1]).tryGet()
proc toSymKey*(key: string): SymKey {.inline.} =
hexToByteArray(key[2 .. ^1], result)
proc toTopic*(topic: string): waku_protocol.Topic {.inline.} =
hexToByteArray(topic[2 .. ^1], result)
# Marshalling from JSON to Nim types that includes format checking
func invalidMsg(name: string): string = "When marshalling from JSON, parameter \"" & name & "\" is not valid"
proc fromJson*(n: JsonNode, argName: string, result: var HexDataStr) =
n.kind.expect(JString, argName)
let hexStr = n.getStr()
if not hexStr.isValidHexData:
raise newException(ValueError, invalidMsg(argName) & " as Ethereum data \"" & hexStr & "\"")
result = hexStr.hexDataStr
proc fromJson*(n: JsonNode, argName: string, result: var Identifier) =
n.kind.expect(JString, argName)
let hexStr = n.getStr()
if not hexStr.isValidIdentifier:
raise newException(ValueError, invalidMsg(argName) & " as a identifier \"" & hexStr & "\"")
result = hexStr.Identifier
proc fromJson*(n: JsonNode, argName: string, result: var UInt256) =
n.kind.expect(JString, argName)
let hexStr = n.getStr()
if not (hexStr.len <= 66 and hexStr.isValidHexQuantity):
raise newException(ValueError, invalidMsg(argName) & " as a UInt256 \"" & hexStr & "\"")
result = readUintBE[256](hexToPaddedByteArray[32](hexStr))
proc fromJson*(n: JsonNode, argName: string, result: var PublicKey) =
n.kind.expect(JString, argName)
let hexStr = n.getStr()
if not hexStr.isValidPublicKey:
raise newException(ValueError, invalidMsg(argName) & " as a public key \"" & hexStr & "\"")
result = hexStr.toPublicKey
proc fromJson*(n: JsonNode, argName: string, result: var PrivateKey) =
n.kind.expect(JString, argName)
let hexStr = n.getStr()
if not hexStr.isValidPrivateKey:
raise newException(ValueError, invalidMsg(argName) & " as a private key \"" & hexStr & "\"")
result = hexStr.toPrivateKey
proc fromJson*(n: JsonNode, argName: string, result: var SymKey) =
n.kind.expect(JString, argName)
let hexStr = n.getStr()
if not hexStr.isValidSymKey:
raise newException(ValueError, invalidMsg(argName) & " as a symmetric key \"" & hexStr & "\"")
result = toSymKey(hexStr)
proc fromJson*(n: JsonNode, argName: string, result: var waku_protocol.Topic) =
n.kind.expect(JString, argName)
let hexStr = n.getStr()
if not hexStr.isValidTopic:
raise newException(ValueError, invalidMsg(argName) & " as a topic \"" & hexStr & "\"")
result = toTopic(hexStr)
# Following procs currently required only for testing, the `createRpcSigs` macro
# requires it as it will convert the JSON results back to the original Nim
# types, but it needs the `fromJson` calls for those specific Nim types to do so
proc fromJson*(n: JsonNode, argName: string, result: var Hash256) =
n.kind.expect(JString, argName)
let hexStr = n.getStr()
if not hexStr.isValidHash256:
raise newException(ValueError, invalidMsg(argName) & " as a Hash256 \"" & hexStr & "\"")
hexToByteArray(hexStr, result.data)