Devon's Cocoa Blog

.h file:

#import 

@interface NSData (NSData_HexAdditions)
- (NSString*) stringWithHexBytes;
+ (NSString*) sha256HashFromString:(NSString*)string;
+ (NSString*) sha256HashFromData:(NSData*)data;

@end

.m file:

#import "NSData+Util.h"
#import 

@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

Implementation .m file:

#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






.h file:

@interface NSString (Hash) 

+(NSString*)randomSaltWithLength:(int)length;

@end

							

http://discussions.apple.com/thread.jspa?messageID=8215707

- (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];
}