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@@ -0,0 +1,102 @@
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+//
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+// DES.swift
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+// CryptoSwift
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+//
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+// Created by Marcin Krzyzanowski on 21/01/2017.
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+// Copyright © 2017 Marcin Krzyzanowski. All rights reserved.
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+//
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+// http://csrc.nist.gov/publications/fips/fips46-3/fips46-3.pdf
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+//
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+
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+/// Data Encryption Standard (DES)
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+public final class DES: BlockCipher {
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+ public static let blockSize: Int = 8
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+
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+ let permutedChoice1:Array<UInt8> = [7, 15, 23, 31, 39, 47, 55, 63,
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+ 6, 14, 22, 30, 38, 46, 54, 62,
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+ 5, 13, 21, 29, 37, 45, 53, 61,
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+ 4, 12, 20, 28, 1, 9, 17, 25,
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+ 33, 41, 49, 57, 2, 10, 18, 26,
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+ 34, 42, 50, 58, 3, 11, 19, 27,
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+ 35, 43, 51, 59, 36, 44, 52, 60]
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+
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+ /// The 64 bits of the input block to be enciphered are first subjected to the following permutation, called the initial permutation.
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+ ///
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+ /// - Parameter block: 8 bytes
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+ /// - Returns: block
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+ fileprivate func initialPermuation(block: inout UInt64) {
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+ // block = b7 b6 b5 b4 b3 b2 b1 b0
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+ var b1 = block >> 48
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+ var b2 = block << 48
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+ block ^= b1 ^ b2 ^ b1 << 48 ^ b2 >> 48
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+
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+ // block = b1 b0 b5 b4 b3 b2 b7 b6
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+ b1 = block >> 32 & 0xff00ff
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+ b2 = (block & 0xff00ff00)
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+ block ^= b1 << 32 ^ b2 ^ b1 << 8 ^ b2 << 24 // exchange b0 b4 with b3 b7
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+
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+
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+ // exchange 4,5,6,7 with 32,33,34,35 etc.
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+ b1 = block & 0x0f0f00000f0f0000
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+ b2 = block & 0x0000f0f00000f0f0
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+ block ^= b1 ^ b2 ^ b1 >> 12 ^ b2 << 12
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+
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+ // exchange 0,1,4,5 with 18,19,22,23
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+ b1 = block & 0x3300330033003300
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+ b2 = block & 0x00cc00cc00cc00cc
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+ block ^= b1 ^ b2 ^ b1 >> 6 ^ b2 << 6
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+
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+ // exchange 0,2,4,6 with 9,11,13,15
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+ b1 = block & 0xaaaaaaaa55555555
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+ block ^= b1 ^ b1 >> 33 ^ b1 << 33
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+ }
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+
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+ /// Expands an input block of 32 bits, producing an output block of 48 bits.
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+ fileprivate func expand(src: UInt32) -> UInt64 {
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+ var src = (src << 5) | (src >> 27)
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+ var result: UInt64 = 0
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+ for _ in 0 ..< 8 {
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+ result <<= 6
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+ result |= UInt64(src) & (1 << 6 - 1)
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+ src = (src << 4) | (src >> 28)
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+ }
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+ return result
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+ }
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+
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+ /// General purpose function to perform block permutations
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+ fileprivate func permute(block: UInt64, permutation: Array<UInt8>) -> UInt64 {
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+ var result: UInt64 = 0
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+ for (idx,value) in permutation.enumerated() {
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+ let bit = (block >> UInt64(value)) & 1
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+ result |= bit << UInt64(permutation.count - 1 - idx)
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+ }
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+ return result
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+ }
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+
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+ fileprivate func generateSubkeys(key: Array<UInt8>) {
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+ //TODO: check endianess of UInt64
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+ let permutedKey = self.permute(block: UInt64(bytes: key), permutation: permutedChoice1)
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+ }
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+}
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+
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+
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+extension DES: Cipher {
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+ public func encrypt<C: Collection>(_ bytes: C) throws -> Array<UInt8> where C.Iterator.Element == UInt8, C.IndexDistance == Int, C.Index == Int, C.SubSequence: Collection, C.SubSequence.Iterator.Element == C.Iterator.Element, C.SubSequence.Index == C.Index, C.SubSequence.IndexDistance == C.IndexDistance {
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+ for chunk in bytes.batched(by: DES.blockSize) {
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+ var b = UInt64(bytes: chunk) //TODO: check endianess
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+ self.initialPermuation(block: &b)
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+ let left = UInt32(b >> 32)
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+ let right = UInt32(truncatingBitPattern: b)
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+
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+ let subKey: UInt64
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+ for i in 0..<16 {
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+ // need generateSubkeys
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+ }
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+ }
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+ return []
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+ }
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+
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+ public func decrypt<C: Collection>(_ bytes: C) throws -> Array<UInt8> where C.Iterator.Element == UInt8, C.IndexDistance == Int, C.Index == Int {
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+ return []
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+ }
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+}
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Marcin Krzyżanowski