//
//  BloggenAWSUtilities.m
//  Bloggen
//
//  Created by Davis Remmel on 2/15/14.
//  Copyright (c) 2014 Davis Remmel. All rights reserved.
//
//  These functions are needed to generate an AWS signature, and to sign
//  the request.

#import "BloggenAWSUtilities.h"
#import <CommonCrypto/CommonHMAC.h>

@implementation BloggenAWSUtilities

+ (NSData *)hmacSHA1WithDigestKey:(NSData *)key stringToEncode:(NSString *)inputString
{
	NSData *inputStringData = [inputString dataUsingEncoding:NSUTF8StringEncoding];
	unsigned int digestLength = 20; // SHA-1 has a length of 160-bits (20-bytes)
	unsigned char digest[digestLength];
	
	CCHmac(kCCHmacAlgSHA1, [key bytes], [key length], [inputStringData bytes], [inputStringData length], digest);
	
	NSData *digestData = [[NSData alloc] initWithBytes:digest length:digestLength];
	
	return digestData;
}

@end