MD5.swift

//
//  md5.swift
//  PHPFramework
//
//  Created by Wesley de Groot on 28-02-16.
//  Copyright © 2016 WDGWV. All rights reserved.
//

import Foundation

/**
 MD5Hashing
 
 A real native Swift 2
 MD5 function
 
 Created by Wesley de Groot. (Twitter: @wesdegroot)
 
 GitHub: @wdg
 
 Thanks for using!
 */
private class MD5Hashing {
    private let shift : [UInt32] = [7, 12, 17, 22, 5, 9, 14, 20, 4, 11, 16, 23, 6, 10, 15, 21]
    private let table: [UInt32] = (0 ..< 64).map {UInt32(0x100000000 * abs(sin(Double($0 + 1))))}
    
	/**
	 MD5 Generator Function.

	 - Parameter str: The string what needs to be encoded.
     - Returns: MD5 hashed string
	 */
	private func md5(str: String) -> String {
		
		var message: [UInt8] = [UInt8](str.utf8)
		
		let messageLenBits = UInt64(message.count) * 8
		message.append(0x80)
		while message.count % 64 != 56 {
			message.append(0)
		}
		
		let lengthBytes = [UInt8](count: 8, repeatedValue: 0)
		UnsafeMutablePointer<UInt64>(lengthBytes).memory = messageLenBits.littleEndian
		message += lengthBytes
		
		var a : UInt32 = 0x67452301
		var b : UInt32 = 0xEFCDAB89
		var c : UInt32 = 0x98BADCFE
		var d : UInt32 = 0x10325476
		
		for chunkOffset in 0.stride(to: message.count, by: 64) {
			let chunk = UnsafePointer<UInt32>(UnsafePointer<UInt8>(message) + chunkOffset)
			let originalA = a
			let originalB = b
			let originalC = c
			let originalD = d
			for j in 0 ..< 64 {
				var f : UInt32 = 0
				var bufferIndex = j
				let round = j >> 4
				switch round {
				case 0:
					f = (b & c) | (~b & d)
				case 1:
					f = (b & d) | (c & ~d)
					bufferIndex = (bufferIndex * 5 + 1) & 0x0F
				case 2:
					f = b ^ c ^ d
					bufferIndex = (bufferIndex * 3 + 5) & 0x0F
				case 3:
					f = c ^ (b | ~d)
					bufferIndex = (bufferIndex * 7) & 0x0F
				default:
					assert(false)
				}
				let sa = shift[(round << 2) | (j&3)]
				let tmp = a &+ f &+ UInt32(littleEndian: chunk[bufferIndex]) &+ table[j]
				a = d
				d = c
				c = b
				b = b &+ (tmp << sa | tmp >> (32 - sa))
			}
			a = a &+ originalA
			b = b &+ originalB
			c = c &+ originalC
			d = d &+ originalD
		}
		
		let result = [UInt8](count: 16, repeatedValue: 0)
		
		for (i, n) in [0: a, 1: b, 2: c, 3: d] {
			UnsafeMutablePointer<UInt32>(result) [i] = n.littleEndian
		}
		
		return "".join(result.map {String(format: "%02x", $0)})
	}
}

extension String {
	/**
	 Make a MD5 Hash for the string.
     
     - Returns: MD5 hashed string
	 */
    public var md5: String {
        get {
            return MD5Hashing().md5(self)
        }
    }
}

/**
 md5 Function.
 
 - Parameter str: The string what needs to be encoded.
 - Returns: MD5 hashed string
 */
func md5(str: String) -> String {
	return str.md5
}

resources

https://github.com/krzyzanowskim/CryptoSwift/blob/master/Sources/CryptoSwift/MD5.swift
https://raw.githubusercontent.com/kvz/phpjs/master/functions/strings/md5.js