import json, macros, sequtils, endians, eth/common, stint, nimcrypto, stew/byteutils type Validator {.packed.} = object # The validator's public key pubkey: Uint256 # What shard the validator's balance will be sent to # after withdrawal withdrawal_shard: int16 # And what address withdrawal_address: EthAddress # The validator's current RANDAO beacon commitment randao_commitment: Hash256 # Current balance balance: int64 # Dynasty where the validator is inducted start_dynasty: int64 # Dynasty where the validator leaves end_dynasty: int64 macro typeToJson*(T: typedesc): untyped = ## Transform a Nim type section in a Json schema ## TODO: Add the possibility to force in lexicographical order let impl = T.getTypeImpl[1].getTypeImpl # Access type implementation as a tree var typeAsJson: JsonNode = newJObject() for field in impl[2]: let (fieldName, fieldType) = ($field[0], $field[1]) # convert name and type to string typeAsJson[fieldName] = %fieldType # % creates a JsonNode from the string that we assign to key = fieldName. result = newStrLitNode($typeAsJson) proc appendBigEndianInt(dst: var seq[byte], src: SomeNumber) = ## Append an int as a big-endian int to a sequence of bytes const size = sizeof(src) proc bigEndian(dst, src: pointer) = when size == 2: # int16 bigEndian16(dst, src) elif size == 4: # int32 bigEndian32(dst, src) elif size == 8: # int64 bigEndian64(dst, src) else: static: doAssert false, "src must be a int16, int32 or int64 or unsigned int of the same size" dst.setLen(dst.len + size) bigEndian(dst[dst.len - size].addr, src.unsafeAddr) proc serializeETH[T](x: T): seq[byte] = ## Serialize an Ethereum type to the PoC serialization format const magic = "\x7FETHEREUM" version = [byte 1, 0] schema = typeToJson(T) # Write magic string and version result = @[] for chr in magic: result.add byte(chr) result.add version # Offset of the raw data (stored as int64 even on 32-bit platform): # - 9 bytes of magic header # - 2 bytes for version # - 8 bytes for offset (int64) # - 32 bytes for Blake2 hash for raw data # - ??? bytes for schema let offset = int64(result.len + sizeof(int64) + sizeof(Hash256) + schema.len) metadataStart = result.len + sizeof(int64) # Write the offset as a Big Endian int64 result.setLen(result.len + sizeof(int64)) bigEndian64(result[result.len - sizeof(int64)].addr, offset.unsafeAddr) # Reserve space for Blake2 hash (256-bit / 32 bytes) result.setLen(result.len + sizeof(Hash256)) # Write the schema for chr in schema: result.add byte(chr) doAssert result.len == offset # Write raw data - this is similar to SimpleSerialize for field in fields(x): when field is UInt256: result.add field.toByteArrayBE elif field is (int16 or int64): result.appendBigEndianInt field elif field is EthAddress: result.add field elif field is Hash256: result.add field.data else: raise newException(ValueError, "Not implemented") doAssert result.len == offset + sizeof(T) # Compute the hash result[metadataStart ..< metadataStart + sizeof(Hash256)] = blake2_256.digest(result[offset ..< result.len]).data # Some reports echo "Schema: " & $schema echo "Schema size: " & $schema.len echo "Raw data offset (== metadata size including schema): " & $offset echo "Raw data size (bytes): " & $sizeof(T) echo "Total size (bytes): " & $result.len when isMainModule: let x = Validator( pubkey: high(Uint256), # 0xFFFF...FFFF withdrawal_shard: 4455, withdrawal_address: hexToPaddedByteArray[20]("0x1234"), randao_commitment: Hash256(data: hexToPaddedByteArray[32]("0xAABBCCDDEEFF")), balance: 100000, start_dynasty: 1, end_dynasty: 2 ) let y = serializeETH(x) echo "\n##################### \n" echo "Byte representation \n" # Byte representation echo y echo "\n##################### \n" echo "Char representation \n" echo cast[seq[char]](y) echo "\n##################### \n" echo "Hex representation \n" echo byteutils.toHex y ################################################################################# # Output # Schema: {"pubkey":"UInt256","withdrawal_shard":"int16","withdrawal_address":"EthAddress","randao_commitment":"Hash256","balance":"int64","start_dynasty":"int64","end_dynasty":"int64"} # Schema size: 175 # Raw data offset (== metadata size including schema): 226 # Raw data size (bytes): 110 # Total size (bytes): 336 # # ##################### # # Byte representation # # @[127, 69, 84, 72, 69, 82, 69, 85, 77, 1, 0, 0, 0, 0, 0, 0, 0, 0, 226, 57, 0, 86, 134, 122, 192, 114, 196, 207, 203, 93, 74, 188, 96, 189, 200, 234, 140, 195, 148, 28, 78, 203, 152, 116, 37, 74, 241, 189, 75, 40, 29, 123, 34, 112, 117, 98, 107, 101, 121, 34, 58, 34, 85, 73, 110, 116, 50, 53, 54, 34, 44, 34, 119, 105, 116, 104, 100, 114, 97, 119, 97, 108, 95, 115, 104, 97, 114, 100, 34, 58, 34, 105, 110, 116, 49, 54, 34, 44, 34, 119, 105, 116, 104, 100, 114, 97, 119, 97, 108, 95, 97, 100, 100, 114, 101, 115, 115, 34, 58, 34, 69, 116, 104, 65, 100, 100, 114, 101, 115, 115, 34, 44, 34, 114, 97, 110, 100, 97, 111, 95, 99, 111, 109, 109, 105, 116, 109, 101, 110, 116, 34, 58, 34, 72, 97, 115, 104, 50, 53, 54, 34, 44, 34, 98, 97, 108,97, 110, 99, 101, 34, 58, 34, 105, 110, 116, 54, 52, 34, 44, 34, 115, 116, 97, 114, 116, 95, 100, 121, 110, 97, 115, 116, 121, 34, 58, 34, 105, 110, 116, 54, 52, 34, 44, 34, 101, 110, 100, 95, 100, 121, 110, 97, 115, 116, 121, 34, 58, 34, 105, 110, 116, 54, 52, 34, 125, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 17, 103, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 18, 52, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 170, 187, 204, 221, 238, 255, 0, 0, 0, 0, 0, 1, 134, 160, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 2] # # ##################### # # Char representation # # @['\x7F', 'E', 'T', 'H', 'E', 'R', 'E', 'U', 'M', '\x01', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\xE2', '9', '\x00', 'V', '\x86', 'z', '\xC0', 'r', '\xC4', '\xCF', '\xCB', ']', 'J', '\xBC', '`', '\xBD', '\xC8', '\xEA', '\x8C', '\xC3', '\x94', '\x1C', 'N', '\xCB', '\x98', 't', '%', 'J', '\xF1', '\xBD', 'K', '(', '\x1D', '{', '\"', 'p', 'u', 'b', 'k', 'e', 'y', '\"', ':', '\"', 'U', 'I', 'n', 't', '2', '5', '6', '\"', ',', '\"', 'w', 'i', 't', 'h', 'd', 'r', 'a', 'w', 'a', 'l', '_', 's', 'h', 'a', 'r', 'd', '\"', ':', '\"', 'i', 'n', 't', '1', '6', '\"', ',', '\"', 'w', 'i', 't', 'h', 'd', 'r', 'a', 'w', 'a', 'l', '_', 'a', 'd', 'd', 'r', 'e', 's', 's', '\"', ':', '\"', 'E', 't', 'h', 'A', 'd', 'd', 'r','e', 's', 's', '\"', ',', '\"', 'r', 'a', 'n', 'd', 'a', 'o', '_', 'c', 'o', 'm', 'm', 'i', 't', 'm', 'e', 'n', 't', '\"', ':', '\"', 'H', 'a', 's', 'h', '2', '5', '6', '\"', ',', '\"', 'b', 'a', 'l', 'a', 'n', 'c', 'e', '\"', ':', '\"', 'i', 'n', 't', '6', '4', '\"', ',', '\"', 's', 't', 'a', 'r', 't', '_', 'd', 'y', 'n', 'a', 's', 't', 'y', '\"', ':', '\"', 'i', 'n', 't', '6', '4', '\"', ',', '\"', 'e', 'n', 'd', '_', 'd', 'y', 'n', 'a', 's', 't', 'y', '\"', ':', '\"', 'i', 'n', 't', '6', '4', '\"', '}', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\xFF', '\x11', 'g', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x12', '4', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\xAA', '\xBB', '\xCC', '\xDD', '\xEE', '\xFF', '\x00', '\x00', '\x00', '\x00', '\x00', '\x01', '\x86', '\xA0', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x01', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x00', '\x02'] # # ##################### # # Hex representation # # 7f455448455245554d010000000000000000e2390056867ac072c4cfcb5d4abc60bdc8ea8cc3941c4ecb9874254af1bd4b281d7b227075626b6579223a2255496e74323536222c227769746864726177616c5f7368617264223a22696e743136222c227769746864726177616c5f61646472657373223a2245746841646472657373222c2272616e64616f5f636f6d6d69746d656e74223a2248617368323536222c2262616c616e6365223a22696e743634222c2273746172745f64796e61737479223a22696e743634222c22656e645f64796e61737479223a22696e743634227dffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff116700000000000000000000000000000000000012340000000000000000000000000000000000000000000000000000aabbccddeeff00000000000186a000000000000000010000000000000002