Add NSDataSequence and process CRC in chunks

CryptoSwift.xcodeproj/project.pbxproj

@@ -59,6 +59,7 @@
 		75B601EB197D6A6C0009B53D /* CryptoSwift.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 754BE45519693E190098E6F3 /* CryptoSwift.framework */; };
 		75BC3AE31A4E412000ADF343 /* CipherBlockMode.swift in Sources */ = {isa = PBXBuildFile; fileRef = 75BC3AE21A4E412000ADF343 /* CipherBlockMode.swift */; };
 		75BE4EB11B1E4A9F007A2B57 /* IntegerConvertible.swift in Sources */ = {isa = PBXBuildFile; fileRef = 75BE4EB01B1E4A9F007A2B57 /* IntegerConvertible.swift */; };
+		75D2D1A01B5689EB000A2615 /* NSDataSequence.swift in Sources */ = {isa = PBXBuildFile; fileRef = 75D2D19F1B5689EB000A2615 /* NSDataSequence.swift */; };
 		75D94E2419B60C08007CB2A4 /* Operators.swift in Sources */ = {isa = PBXBuildFile; fileRef = 75D94E2319B60C08007CB2A4 /* Operators.swift */; };
 		75D94E2619B60C4F007CB2A4 /* UInt32Extension.swift in Sources */ = {isa = PBXBuildFile; fileRef = 75D94E2519B60C4F007CB2A4 /* UInt32Extension.swift */; };
 		75D94E2819B60DDE007CB2A4 /* UInt64Extension.swift in Sources */ = {isa = PBXBuildFile; fileRef = 75D94E2719B60DDE007CB2A4 /* UInt64Extension.swift */; };
@@ -170,6 +171,7 @@
 		75B0A56F1AB1A1BB000BD8D2 /* PKCS5.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PKCS5.swift; sourceTree = "<group>"; };
 		75BC3AE21A4E412000ADF343 /* CipherBlockMode.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CipherBlockMode.swift; sourceTree = "<group>"; };
 		75BE4EB01B1E4A9F007A2B57 /* IntegerConvertible.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = IntegerConvertible.swift; sourceTree = "<group>"; };
+		75D2D19F1B5689EB000A2615 /* NSDataSequence.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = NSDataSequence.swift; sourceTree = "<group>"; };
 		75D94E2319B60C08007CB2A4 /* Operators.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Operators.swift; sourceTree = "<group>"; };
 		75D94E2519B60C4F007CB2A4 /* UInt32Extension.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = UInt32Extension.swift; sourceTree = "<group>"; };
 		75D94E2719B60DDE007CB2A4 /* UInt64Extension.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = UInt64Extension.swift; sourceTree = "<group>"; };
@@ -256,6 +258,7 @@
 				75164E4819AD30AC00737F30 /* Utils.swift */,
 				758C764019B61AE500653BC6 /* Generics.swift */,
 				75BE4EB01B1E4A9F007A2B57 /* IntegerConvertible.swift */,
+				75D2D19F1B5689EB000A2615 /* NSDataSequence.swift */,
 				754BE45819693E190098E6F3 /* Supporting Files */,
 			);
 			path = CryptoSwift;
@@ -431,6 +434,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				75D2D1A01B5689EB000A2615 /* NSDataSequence.swift in Sources */,
 				75D94E2819B60DDE007CB2A4 /* UInt64Extension.swift in Sources */,
 				751C5C3D19B26B000094C75D /* Poly1305.swift in Sources */,
 				7552614E1993051E000D2B20 /* Hash.swift in Sources */,

CryptoSwift.xcodeproj/xcshareddata/xcschemes/CryptoSwift.xcscheme

@@ -37,10 +37,10 @@
       </BuildActionEntries>
    </BuildAction>
    <TestAction
+      buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      shouldUseLaunchSchemeArgsEnv = "YES"
-      buildConfiguration = "Release">
+      shouldUseLaunchSchemeArgsEnv = "YES">
       <Testables>
          <TestableReference
             skipped = "NO">
@@ -76,15 +76,18 @@
             ReferencedContainer = "container:CryptoSwift.xcodeproj">
          </BuildableReference>
       </MacroExpansion>
+      <AdditionalOptions>
+      </AdditionalOptions>
    </TestAction>
    <LaunchAction
+      buildConfiguration = "Debug"
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       launchStyle = "0"
       useCustomWorkingDirectory = "NO"
-      buildConfiguration = "Debug"
       ignoresPersistentStateOnLaunch = "NO"
       debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
       allowLocationSimulation = "YES">
       <MacroExpansion>
          <BuildableReference
@@ -99,10 +102,10 @@
       </AdditionalOptions>
    </LaunchAction>
    <ProfileAction
+      buildConfiguration = "Release"
       shouldUseLaunchSchemeArgsEnv = "YES"
       savedToolIdentifier = ""
       useCustomWorkingDirectory = "NO"
-      buildConfiguration = "Release"
       debugDocumentVersioning = "YES">
       <MacroExpansion>
          <BuildableReference

CryptoSwift/CRC.swift

@@ -45,10 +45,14 @@ final class CRC {
     
     func crc32(message:NSData) -> NSData {
         var crc:UInt32 = 0xffffffff
-        for b in message.arrayOfBytes() {
-            let idx = Int((crc ^ UInt32(b)) & 0xff)
-            crc = (crc >> 8) ^ table[idx]
+        
+        for chunk in NSDataSequence(chunkSize: 256, data: message) {
+            for b in chunk.arrayOfBytes() {
+                let idx = Int((crc ^ UInt32(b)) & 0xff)
+                crc = (crc >> 8) ^ table[idx]
+            }
         }
+        
         crc = crc ^ 0xffffffff
         
         // reverse bytes

CryptoSwift/NSDataSequence.swift

@@ -0,0 +1,26 @@
+//
+//  NSDataSequence.swift
+//  CryptoSwift
+//
+//  Created by Marcin Krzyzanowski on 15/07/15.
+//  Copyright © 2015 Marcin Krzyzanowski. All rights reserved.
+//
+
+import Foundation
+
+struct NSDataSequence: SequenceType {
+    
+    let chunkSize: Int
+    let data: NSData
+    
+    func generate() -> AnyGenerator<NSData> {
+        
+        var offset:Int = 0
+        
+        return anyGenerator {
+            let result = self.data.subdataWithRange(NSRange(location: offset, length: min(self.chunkSize, self.data.length - offset)))
+            offset += result.length
+            return result.length > 0 ? result : nil
+        }
+    }
+}