OAHMAC_SHA1SignatureProvider.m

//
//  OAHMAC_SHA1SignatureProvider.m
//  OAuthConsumer
//
//  Created by Jon Crosby on 10/19/07.
//  Copyright 2007 Kaboomerang LLC. All rights reserved.
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.


#import "OAHMAC_SHA1SignatureProvider.h"

#include "hmac.h"
#include "Base64Transcoder.h"

#import <CommonCrypto/CommonDigest.h>
#import <CommonCrypto/CommonHMAC.h>

@implementation OAHMAC_SHA1SignatureProvider

- (NSString *)name {
    return @"HMAC-SHA1";
}

- (NSString *)signClearText:(NSString *)text withSecret:(NSString *)secret {
    NSData *secretData = [[secret dataUsingEncoding:NSUTF8StringEncoding] retain];
    NSData *clearTextData = [[text dataUsingEncoding:NSUTF8StringEncoding] retain];
    unsigned char result[20];
    hmac_sha1((unsigned char *)[clearTextData bytes], [clearTextData length], (unsigned char *)[secretData bytes], [secretData length], result);
	[secretData release];
	[clearTextData release];
    
    //Base64 Encoding
    
    char base64Result[32];
    size_t theResultLength = 32;
    Base64EncodeData(result, 20, base64Result, &theResultLength);
    NSData *theData = [NSData dataWithBytes:base64Result length:theResultLength];
    
    NSString *base64EncodedResult = [[[NSString alloc] initWithData:theData encoding:NSUTF8StringEncoding] autorelease];
    
    return base64EncodedResult;
}

@end