add ISO78164 padding

CryptoSwift.xcodeproj/project.pbxproj

@@ -7,6 +7,11 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		0AF023D5230F2B0F008E4E68 /* ISO78164Padding.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0AF023D4230F2B0F008E4E68 /* ISO78164Padding.swift */; };
+		0AF023D6230F2B0F008E4E68 /* ISO78164Padding.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0AF023D4230F2B0F008E4E68 /* ISO78164Padding.swift */; };
+		0AF023D7230F2B0F008E4E68 /* ISO78164Padding.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0AF023D4230F2B0F008E4E68 /* ISO78164Padding.swift */; };
+		0AF023D8230F2B0F008E4E68 /* ISO78164Padding.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0AF023D4230F2B0F008E4E68 /* ISO78164Padding.swift */; };
+		0AF023D9230F2B0F008E4E68 /* ISO78164Padding.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0AF023D4230F2B0F008E4E68 /* ISO78164Padding.swift */; };
 		0EE73E71204D598100110E11 /* CMAC.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0EE73E70204D598100110E11 /* CMAC.swift */; };
 		0EE73E74204D59C200110E11 /* CMACTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 0EE73E72204D599C00110E11 /* CMACTests.swift */; };
 		14156CE52011422400DDCFBC /* ChaCha20Poly1305Tests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 14156CE42011422400DDCFBC /* ChaCha20Poly1305Tests.swift */; };
@@ -194,6 +199,7 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		0AF023D4230F2B0F008E4E68 /* ISO78164Padding.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ISO78164Padding.swift; sourceTree = "<group>"; };
 		0EE73E70204D598100110E11 /* CMAC.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CMAC.swift; sourceTree = "<group>"; };
 		0EE73E72204D599C00110E11 /* CMACTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CMACTests.swift; sourceTree = "<group>"; };
 		14156CE42011422400DDCFBC /* ChaCha20Poly1305Tests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ChaCha20Poly1305Tests.swift; sourceTree = "<group>"; };
@@ -508,6 +514,7 @@
 		75EC52371EE8B6CA0048EB3B /* CryptoSwift */ = {
 			isa = PBXGroup;
 			children = (
+				0AF023D4230F2B0F008E4E68 /* ISO78164Padding.swift */,
 				7529366820683DFC00195874 /* AEAD */,
 				75EC52381EE8B6CA0048EB3B /* AES.swift */,
 				751EE9771F93996100161FFC /* AES.Cryptors.swift */,
@@ -821,6 +828,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				0AF023D6230F2B0F008E4E68 /* ISO78164Padding.swift in Sources */,
 				75211F95207249D8004E41F8 /* AppDelegate.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -829,6 +837,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				0AF023D5230F2B0F008E4E68 /* ISO78164Padding.swift in Sources */,
 				75EC52861EE8B8170048EB3B /* CFB.swift in Sources */,
 				75EC52901EE8B81A0048EB3B /* Collection+Extension.swift in Sources */,
 				0EE73E71204D598100110E11 /* CMAC.swift in Sources */,
@@ -910,6 +919,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				0AF023D7230F2B0F008E4E68 /* ISO78164Padding.swift in Sources */,
 				75C2E76D1D55F097003D2BCA /* Access.swift in Sources */,
 				75482EA41CB310B7001F66A5 /* PBKDF.swift in Sources */,
 				758A94291A65C67400E46135 /* HMACTests.swift in Sources */,
@@ -940,6 +950,7 @@
 				7564F0552072EAEB00CA5A96 /* ExtensionsTestPerf.swift in Sources */,
 				7564F0562072EAEB00CA5A96 /* DigestTestsPerf.swift in Sources */,
 				81F279E22181F5C500449EDA /* ScryptTestsPerf.swift in Sources */,
+				0AF023D9230F2B0F008E4E68 /* ISO78164Padding.swift in Sources */,
 				7564F0572072EAEB00CA5A96 /* TestsPerformance.swift in Sources */,
 				7564F0582072EAEB00CA5A96 /* AESTestsPerf.swift in Sources */,
 			);
@@ -955,6 +966,7 @@
 				7595C15C2072E5B900EA1A5F /* ExtensionsTestPerf.swift in Sources */,
 				7595C1582072E5B900EA1A5F /* DigestTestsPerf.swift in Sources */,
 				81F279E12181F5C500449EDA /* ScryptTestsPerf.swift in Sources */,
+				0AF023D8230F2B0F008E4E68 /* ISO78164Padding.swift in Sources */,
 				7595C14D2072E48C00EA1A5F /* TestsPerformance.swift in Sources */,
 				7595C1592072E5B900EA1A5F /* AESTestsPerf.swift in Sources */,
 			);

README.md

@@ -80,6 +80,7 @@ Good mood
   PKCS#5
 | [PKCS#7](http://tools.ietf.org/html/rfc5652#section-6.3)
 | [Zero padding](https://en.wikipedia.org/wiki/Padding_(cryptography)#Zero_padding)
+| [ISO78164](http://www.embedx.com/pdfs/ISO_STD_7816/info_isoiec7816-4%7Bed21.0%7Den.pdf)
 | No padding
 
 #### Authenticated Encryption with Associated Data (AEAD)

Sources/CryptoSwift/ISO78164Padding.swift

@@ -0,0 +1,42 @@
+//
+//  CryptoSwift
+//
+//  Copyright (C) Marcin Krzyżanowski <marcin@krzyzanowskim.com>
+//  This software is provided 'as-is', without any express or implied warranty.
+//
+//  In no event will the authors be held liable for any damages arising from the use of this software.
+//
+//  Permission is granted to anyone to use this software for any purpose,including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:
+//
+//  - The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation is required.
+//  - Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+//  - This notice may not be removed or altered from any source or binary distribution.
+//
+
+import Foundation
+
+// First byte is 0x80, rest is zero padding
+// http://www.crypto-it.net/eng/theory/padding.html
+// http://www.embedx.com/pdfs/ISO_STD_7816/info_isoiec7816-4%7Bed21.0%7Den.pdf
+struct ISO78164Padding: PaddingProtocol {
+  init() {
+  }
+
+  func add(to bytes: Array<UInt8>, blockSize: Int) -> Array<UInt8> {
+    var padded = Array(bytes)
+    padded.append(0x80)
+
+    while (padded.count % blockSize) != 0 {
+      padded.append(0x00)
+    }
+    return padded
+  }
+
+  func remove(from bytes: Array<UInt8>, blockSize _: Int?) -> Array<UInt8> {
+    if let idx = bytes.lastIndex(of: 0x80) {
+      return Array(bytes[..<idx])
+    } else {
+      return bytes
+    }
+  }
+}

Sources/CryptoSwift/Padding.swift

@@ -19,7 +19,7 @@ public protocol PaddingProtocol {
 }
 
 public enum Padding: PaddingProtocol {
-  case noPadding, zeroPadding, pkcs7, pkcs5
+  case noPadding, zeroPadding, pkcs7, pkcs5, iso78164
 
   public func add(to: Array<UInt8>, blockSize: Int) -> Array<UInt8> {
     switch self {
@@ -31,6 +31,8 @@ public enum Padding: PaddingProtocol {
         return PKCS7.Padding().add(to: to, blockSize: blockSize)
       case .pkcs5:
         return PKCS5.Padding().add(to: to, blockSize: blockSize)
+      case .iso78164:
+        return ISO78164Padding().add(to: to, blockSize: blockSize)
     }
   }
 
@@ -44,6 +46,8 @@ public enum Padding: PaddingProtocol {
         return PKCS7.Padding().remove(from: from, blockSize: blockSize)
       case .pkcs5:
         return PKCS5.Padding().remove(from: from, blockSize: blockSize)
+      case .iso78164:
+        return ISO78164Padding().remove(from: from, blockSize: blockSize)
     }
   }
 }

Tests/CryptoSwiftTests/PaddingTests.swift

@@ -60,11 +60,41 @@ final class PaddingTests: XCTestCase {
     XCTAssertEqual(padding.remove(from: padding.add(to: input, blockSize: 16), blockSize: 16), input, "ZeroPadding failed")
   }
 
+  func testISO78164_0() {
+    let input: Array<UInt8> = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 0x80]
+    let expected: Array<UInt8> = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 0x80, 0x80]
+    let padded = ISO78164Padding().add(to: input, blockSize: 16)
+    XCTAssertEqual(padded, expected, "ISO78164 failed")
+    let clean =  ISO78164Padding().remove(from: padded, blockSize: nil)
+    XCTAssertEqual(clean, input, "ISO78164 failed")
+  }
+
+  func testISO78164_1() {
+    let input: Array<UInt8> = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 0]
+    let expected: Array<UInt8> = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 0, 0x80] + [UInt8](repeating: UInt8(0), count: 15)
+    let padded =  ISO78164Padding().add(to: input, blockSize: 16)
+    XCTAssertEqual(padded, expected, "ISO78164 failed")
+    let clean =  ISO78164Padding().remove(from: padded, blockSize: nil)
+    XCTAssertEqual(clean, input, "ISO78164 failed")
+  }
+
+  func testISO78164_2() {
+    let input: Array<UInt8> = []
+    let expected: Array<UInt8> = [0x80] + [UInt8](repeating: UInt8(0), count: 15)
+    let padded =  ISO78164Padding().add(to: input, blockSize: 16)
+    XCTAssertEqual(padded, expected, "ISO78164 failed")
+    let clean =  ISO78164Padding().remove(from: padded, blockSize: nil)
+    XCTAssertEqual(clean, input, "ISO78164 failed")
+  }
+
   static let allTests = [
     ("testPKCS7_0", testPKCS7_0),
     ("testPKCS7_1", testPKCS7_1),
     ("testPKCS7_2", testPKCS7_2),
     ("testZeroPadding1", testZeroPadding1),
-    ("testZeroPadding2", testZeroPadding2)
+    ("testZeroPadding2", testZeroPadding2),
+    ("testISO78164_0", testISO78164_0),
+    ("testISO78164_1", testISO78164_1),
+    ("testISO78164_2", testISO78164_2)
   ]
 }