TPDummyDecrypter.m [plain text]
/*
* Copyright (c) 2017 Apple Inc. All Rights Reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
#import "TPDummyDecrypter.h"
@implementation TPDummyDecrypter
+ (instancetype)dummyDecrypter
{
return [[TPDummyDecrypter alloc] init];
}
- (nullable NSData *)decryptData:(NSData *)ciphertext
withKey:(NSData *)key
error:(NSError **)error
{
// Repeating-key XOR
NSMutableData *plaintext = [NSMutableData dataWithLength:ciphertext.length];
uint8_t *plainbytes = plaintext.mutableBytes;
const uint8_t *cipherbytes = ciphertext.bytes;
const uint8_t *keybytes = key.bytes;
NSUInteger keylen = key.length;
for (NSUInteger i = 0; i < ciphertext.length; i++) {
plainbytes[i] = cipherbytes[i] ^ keybytes[i }
return plaintext;
}
@end