alephao/swift-rlp

Recursive Length Prefix encoding written in Swift

SwiftRLP

This is a simple, pure Swift implementation of Recursive Length Prefix Encoding, a serialisation method for encoding arbitrarily structured binary data (byte arrays).

RLP Encoding is used in Ethereum. You can read more about it here:

• Ethereum Wiki - RLP
• Ethereum Yellowpaper (Appendix B)

Library Usage

SwiftRLP is available through Swift Package Manager.

Adding SwiftRLP as a dependency is as easy as adding it to the dependencies value of your Package.swift.

dependencies: [
  .package(url: "https://github.com/alephao/swift-rlp.git", from: "0.0.6")
],
targets: [
    .target(
      name: "MyTarget",
      dependencies: [
        .product(name: "SwiftRLP", package: "swift-rlp")
      ]
    ),
]

Encoding

import SwiftRLP

let encoder = RLPEncoder()

// String Encoding
try encoder.encode(.string("dog"))
try encoder.encode(string: "dog")

// Array Encoding
try encoder.encode(.array(["d", "o", "g"]))

Decoding

import SwiftRLP

let encodedData = try RLPEncoder().encode(string: "dog")

let decoder = RLPDecoder()
try decoder.decode(from: encodedData) // RLPValue.string("dog")

CLI

Currently, the CLI is only available via source code. To use it, clone this repo and run:

Encoding

$ swift run cli encode dog
> 0x83646F67

Decoding

$ swift run cli decode 0x83646F67
> string("dog")

License

SwiftRLP is released under an MIT license. See LICENSE for more information.

swift-rlp's Issues

Is the rule of the RLP the same as that of Ethereum?

Our project want to use Ethereum RLP,But it cannot be used in iOS,So I want to write a code by reference to Ethereum.And then I found you.
Anyway,thank you very much

Update to Swift 4.2

Add decoding method

The algorithm to decode an be found here on ethereum/wiki/RLP, they also have an implementation example in js.

Suggestion for the function signature:
func decode(_ data: Data) throws -> Data

Manual Installation Instructions Extensions missing

Manual installation instructions specify that in order to install developers must

Download and drop RLP.swift inside your project.

but it's also required to import the UInt32+Extensions.swift file

I also suggest to rename UInt32+Extensions.swift to UInt32+byteArrayLittleEndian.swift

Update to Swift 5.0

Add support to Swift Package Manager

Add support to Swift Package Manager by creating a Package.swift

Swift Package Manager/Usage.md