xcode iphone base64 encode/decode

첨부파일을 다운로드 받고 import 후 아래와 같이 사용
1136870320.h

 NSString *sourceString = @"username:password";  
 NSLog(@"Original string: %@", sourceString);  
 NSData *sourceData = [sourceString dataUsingEncoding:NSUTF8StringEncoding];  
 
 NSString *base64EncodedString = [sourceData base64Encoding];  
 NSLog([NSString stringWithFormat:@"Encoded form: %@", base64EncodedString]);  
 
 NSData *decodedData = [NSData dataWithBase64EncodedString:base64EncodedString];  
 NSString *decodedString = [[[NSString alloc] initWithData:decodedData encoding:NSUTF8StringEncoding] autorelease];  
 NSLog([NSString stringWithFormat:@"Decoded again: %@",decodedString]);