dnadoba/BinaryKit

💾🔍🧮 BinaryKit helps you to break down binary data into bits and bytes, easily access specific parts and write data to binary.

BinaryKit

BinaryKit helps you to break down binary data into bits and bytes, easily access specific parts and write data to binary. Bytes in the buffer are expected to be in network byte order (big-endian). Multibyte Integers will automatically be convert from host byte order to network byte order during writes, and from network byte order to host byte order on integer reads. This is a fork of Cosmo/BinaryKit. Autogenerated Documentation can be found at https://dnadoba.github.io/BinaryKit.
Contributions are welcome.

Access Bytes

By using any read* method (readByte(), readBytes(quantitiy:), readBit(), …) of BinaryReader, BinaryKit will increment an internal cursor (or reading offset) to the end of the requested bit or byte, so the next read* method can continue from there.

Any get* method (getByte(index:), getBytes(range:), getBit(index:), …) will give access to binary data at any given location — without incrementing the internal cursor.

Here are the methods you can call:

var binary = BinaryReader(bytes: [0xDE, 0xAD, 0xBE, 0xEF, …])

// Reads exactly 1 byte and
// increments the cursor by 1 byte 
try binary.readByte()

// Reads the next 4 bytes and
// increments the cursor by 4 bytes
try binary.readBytes(4)

// Reads the next 1 bit and
// increments the cursor by 1 bit
try binary.readBit()

// Reads the next 4 bits and
// increments the cursor by 4 bits
try binary.readBits(4)

Example

var binary = BinaryReader(bytes: [0b1_1_0_1_1_1_0_0])
//                                  | | | | | | | | 
//                                  | | | | | | | try binary.readBit()  // 0
//                                  | | | | | | try binary.readBit()    // 0
//                                  | | | | | try binary.readBit()      // 1
//                                  | | | | try binary.readBit()        // 1
//                                  | | | try binary.readBit()          // 1
//                                  | | try binary.readBit()            // 0
//                                  | try binary.readBit()              // 1
//                                  try binary.readBit()                // 1

This shows how easy it is, to break down an IPv4 header.

var binary = BinaryReader(bytes: [0x1B, 0x44, …])
let version                         = try binary.readBits(4)
let internetHeaderLength            = try binary.readBits(4)
let differentiatedServicesCodePoint = try binary.readBits(6)
let explicitCongestionNotification  = try binary.readBits(2)
let totalLength                     = try binary.readBytes(2)
let identification                  = try binary.readBytes(2)
let flags                           = try binary.readBits(4)
let fragmentOffset                  = try binary.readBits(12)
let timeToLive                      = try binary.readByte()
let protocolNumber                  = try binary.readByte()
let headerChecksum                  = try binary.readBytes(2)
let sourceIpAddress                 = try binary.readBytes(4)
let destinationIpAddress            = try binary.readBytes(4)
...

Store Bytes

Use the write* methods of BinaryWriter to store different types to binary.

var binary = BinaryWriter<[UInt8]>()
binary.writeInt32(1_350_849_546)
binary.writeString("Hello World!")
binary.writeBytes([0xFF, 0xCC, 0x00, 0x01])
binary.writeBool(true)

License

BinaryKit is released under the MIT License.