First drafting for Password generator.

Extended Settings handling to be able to use Tabs

MacPass/NSString+MPPasswordCreation.m

@@ -0,0 +1,65 @@
+//
+//  NSString+MPPasswordCreation.m
+//  MacPass
+//
+//  Created by Michael Starke on 29.03.13.
+//  Copyright (c) 2013 HicknHack Software GmbH. All rights reserved.
+//
+
+#import "NSString+MPPasswordCreation.h"
+#import "NSData+MPRandomBytes.h"
+
+
+@implementation NSString (MPPasswordCreationTools)
+
++ (NSDictionary *)_createPasswordSet:(MPPasswordCharacterFlags)flags {
+  return [NSDictionary dictionary];
+}
+
+- (NSDictionary *)_createPasswordSet:(MPPasswordCharacterFlags)flags {
+  return [NSString _createPasswordSet:flags];
+}
+
+@end
+
+@implementation NSString (MPPasswordCreation)
+
++ (NSString *)passwordFromString:(NSString *)source length:(NSUInteger)length {
+  NSMutableString *password = [[NSMutableString alloc] initWithCapacity:length];
+  while([password length] < length) {
+    NSData *randomData = [NSData dataWithRandomBytes:2];
+    NSNumber *number = [NSNumber numberWithUnsignedChar:(unsigned char)[randomData bytes]];
+    NSLog(@"Random number:%@", number);
+    [password appendString:@"U"];
+  }
+  return [password autorelease];
+}
+
++ (NSString *)passwordWithCharactersets:(MPPasswordCharacterFlags)allowedCharacters length:(NSUInteger)length {
+  NSDictionary *characterSet = [self _createPasswordSet:allowedCharacters];
+  NSMutableString *password = [NSMutableString stringWithCapacity:length];
+  while([password length] < length) {
+    // decide what charactersupset to use
+    // gather random character of selected set
+    NSString *characters = characterSet[@(MPPasswordCharactersLowerCase)];
+    [password appendString:[characters randomCharacter]];
+  }
+  return password;
+}
+
+- (NSString *)passwordWithLength:(NSUInteger)length {
+  return [NSString passwordFromString:self length:length];
+}
+
+- (NSString *)randomCharacter {
+  NSUInteger randomByteSize = floor(log2([self length]));
+  NSData *randomData = [NSData dataWithRandomBytes:randomByteSize];
+  NSNumber *number = [NSNumber numberWithUnsignedChar:(unsigned char)[randomData bytes]];
+  NSUInteger randomIndex = [number integerValue];
+  if(randomIndex > 0 || randomIndex >= [self length]) {
+    return nil;
+  }
+  return [self substringFromIndex:[number integerValue]];
+}
+
+@end