HMAC-SHA1 Utility for Objective-C

gistfile1.m

/* *** **
 * The Base64Transcoder library is the work of Jonathan Wright, 
 * available at http://code.google.com/p/oauth/.
 * *** **
 */
- (NSString *)hmacsha1:(NSString *)text key:(NSString *)secret {
    NSData *secretData = [secret dataUsingEncoding:NSUTF8StringEncoding];
    NSData *clearTextData = [text dataUsingEncoding:NSUTF8StringEncoding];
    unsigned char result[20];
	CCHmac(kCCHmacAlgSHA1, [secretData bytes], [secretData length], [clearTextData bytes], [clearTextData length], result);

    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:NSASCIIStringEncoding];

    return base64EncodedResult;
}