RosettaCodeData/Task/MD5-Implementation/Swift/md5-implementation-1.swift

127 lines
4.5 KiB
Swift

import Foundation
public class MD5 {
/** specifies the per-round shift amounts */
private let s: [UInt32] = [7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22,
5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20,
4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23,
6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21]
/** binary integer part of the sines of integers (Radians) */
private let K: [UInt32] = (0 ..< 64).map { UInt32(0x100000000 * abs(sin(Double($0 + 1)))) }
let a0: UInt32 = 0x67452301
let b0: UInt32 = 0xefcdab89
let c0: UInt32 = 0x98badcfe
let d0: UInt32 = 0x10325476
private var message: NSData
//MARK: Public
public init(_ message: NSData) {
self.message = message
}
public func calculate() -> NSData? {
var tmpMessage: NSMutableData = NSMutableData(data: message)
let wordSize = sizeof(UInt32)
var aa = a0
var bb = b0
var cc = c0
var dd = d0
// Step 1. Append Padding Bits
tmpMessage.appendBytes([0x80]) // append one bit (Byte with one bit) to message
// append "0" bit until message length in bits 448 (mod 512)
while tmpMessage.length % 64 != 56 {
tmpMessage.appendBytes([0x00])
}
// Step 2. Append Length a 64-bit representation of lengthInBits
var lengthInBits = (message.length * 8)
var lengthBytes = lengthInBits.bytes(64 / 8)
tmpMessage.appendBytes(reverse(lengthBytes));
// Process the message in successive 512-bit chunks:
let chunkSizeBytes = 512 / 8
var leftMessageBytes = tmpMessage.length
for var i = 0; i < tmpMessage.length; i = i + chunkSizeBytes, leftMessageBytes -= chunkSizeBytes {
let chunk = tmpMessage.subdataWithRange(NSRange(location: i, length: min(chunkSizeBytes,leftMessageBytes)))
// break chunk into sixteen 32-bit words M[j], 0 j 15
// println("wordSize \(wordSize)");
var M:[UInt32] = [UInt32](count: 16, repeatedValue: 0)
for x in 0..<M.count {
var range = NSRange(location:x * wordSize, length: wordSize)
chunk.getBytes(&M[x], range:range);
}
// Initialize hash value for this chunk:
var A:UInt32 = a0
var B:UInt32 = b0
var C:UInt32 = c0
var D:UInt32 = d0
var dTemp:UInt32 = 0
// Main loop
for j in 0...63 {
var g = 0
var F:UInt32 = 0
switch (j) {
case 0...15:
F = (B & C) | ((~B) & D)
g = j
break
case 16...31:
F = (D & B) | (~D & C)
g = (5 * j + 1) % 16
break
case 32...47:
F = B ^ C ^ D
g = (3 * j + 5) % 16
break
case 48...63:
F = C ^ (B | (~D))
g = (7 * j) % 16
break
default:
break
}
dTemp = D
D = C
C = B
B = B &+ rotateLeft((A &+ F &+ K[j] &+ M[g]), s[j])
A = dTemp
}
aa = aa &+ A
bb = bb &+ B
cc = cc &+ C
dd = dd &+ D
}
var buf: NSMutableData = NSMutableData();
buf.appendBytes(&aa, length: wordSize)
buf.appendBytes(&bb, length: wordSize)
buf.appendBytes(&cc, length: wordSize)
buf.appendBytes(&dd, length: wordSize)
return buf.copy() as? NSData;
}
//MARK: Class
class func calculate(message: NSData) -> NSData?
{
return MD5(message).calculate();
}
//MARK: Private
private func rotateLeft(x:UInt32, _ n:UInt32) -> UInt32 {
return (x &<< n) | (x &>> (32 - n))
}
}