Devon’s Cocoa Blog

#import <Foundation/Foundation.h>
 
@interface NSData (NSData_HexAdditions)
- (NSString*) stringWithHexBytes;
+ (NSString*) sha256HashFromString:(NSString*)string;
+ (NSString*) sha256HashFromData:(NSData*)data;
 
@end

#import "NSData+Util.h"
#import <CommonCrypto/CommonDigest.h>
 
@implementation NSData (NSData_HexAdditions)
- (NSString*) stringWithHexBytes {
	NSMutableString *stringBuffer = [NSMutableString
									 stringWithCapacity:([self length] * 2)];
	const unsigned char *dataBuffer = [self bytes];
	int i;
 
	for (i = 0; i < [self length]; ++i)
		[stringBuffer appendFormat:@"%02x", (unsigned long)dataBuffer[ i ]];
 
	return [[stringBuffer copy] autorelease];
}
 
+ (NSString*) sha256HashFromData:(NSData*)data
{
	return [NSData sha256HashFromString:[NSString stringWithCString:(const char*)[data bytes] length:[data length]]];
}
 
+ (NSString*) sha256HashFromString:(NSString*)string
{
	unsigned char hashedChars[CC_SHA512_DIGEST_LENGTH];
 
	CC_SHA512([string UTF8String],
			  [string lengthOfBytesUsingEncoding:NSUTF8StringEncoding], 
			  hashedChars);
	NSData * hashedData = [NSData dataWithBytes:hashedChars length:CC_SHA512_DIGEST_LENGTH];	
	NSData* tmp = [[NSData alloc] initWithData:hashedData];
	NSString* ret = [tmp stringWithHexBytes];
	[tmp release];
	return ret;
}
@end

#import "NSString+Hash.h"
 
 
@implementation NSString (Hash)
 
 
+(NSString*)randomSaltWithLength:(int)length
{
	char chars[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
	NSMutableString* ret = [[[NSMutableString alloc] initWithCapacity:length] autorelease];
	srandomdev();
 
	for(int i=0;i<length;i++)
	{
		int index = random()%52;
		char a = chars[index];
		[ret appendString:[NSString stringWithCString:&a length:1]];
	}
 
	return ret;
}
 
@end

@interface NSString (Hash) 
 
+(NSString*)randomSaltWithLength:(int)length;
 
@end

- (void) createProgressionAlertWithMessage:(NSString *)message withActivity:(BOOL)activity
{
  progressAlert = [[UIAlertView alloc] initWithTitle: message
                                             message: @"Please wait..."
                                            delegate: self
                                   cancelButtonTitle: nil
                                   otherButtonTitles: nil];
 
 
  // Create the progress bar and add it to the alert
  if (activity) {
    activityView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhite];
    activityView.frame = CGRectMake(139.0f-18.0f, 80.0f, 37.0f, 37.0f);
    [progressAlert addSubview:activityView];
    [activityView startAnimating];
  } else {
    progressView = [[UIProgressView alloc] initWithFrame:CGRectMake(30.0f, 80.0f, 225.0f, 90.0f)];
    [progressAlert addSubview:progressView];
    [progressView setProgressViewStyle: UIProgressViewStyleBar];
  }
  [progressAlert show];
  [progressAlert release];
}