我想在目标 c 中使用没有填充的 CFB 加密创建 AES 128答案

【问题标题】：I Want to Create AES 128 using CFB Encryption with No Padding in objective c我想在目标 c 中使用没有填充的 CFB 加密创建 AES 128
【发布时间】：2016-05-04 13:51:54
【问题描述】：

我想使用无填充的 CFB 加密创建 AES 128，即

示例 1：秘密数据是“HELLO WORLD” 键：10 A5 88 69 D7 4B E5 A3 74 CF 86 7C FB 47 38 59 四：00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 明文（未加密）：48 45 4C 4C 4F 20 57 4F 52 4C 44 密文：25 60 52 25 0B 90 06 AF 1C E6 2B

但我得到的是加密的十六进制字符串 == 即没有字符串。我的加密成功但没有加密数据有什么建议吗？

代码如下：

NSData *commandData = [@"HELLO WORLD" dataUsingEncoding:NSASCIIStringEncoding];
calling Method [commandData AES128OperationWithCreate:kCCEncrypt key:@"10a58869d74be5a374cf867cfb473859" iv:@"00000000000000000000000000000000"]

@implementation NSData (AES)
- (NSData *)AES128OperationWithCreate:(CCOperation)operation key:(NSString *)key iv:(NSString *)iv{
 char ivPtr[kCCBlockSizeAES128 + 1];
            bzero(ivPtr, sizeof(ivPtr));
            if (iv) {
                [iv getCString:ivPtr maxLength:sizeof(ivPtr) encoding:NSUTF8StringEncoding];
            }

            char keyPtr[kCCKeySizeAES128 + 1];
            bzero(keyPtr, sizeof(keyPtr));
            [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];


            CCCryptorRef cryptor = NULL;
            CCCryptorStatus result = CCCryptorCreateWithMode(operation,
                                                             kCCModeCFB,
                                                             kCCAlgorithmAES128,
                                                             ccNoPadding,
                                                             ivPtr,
                                                             keyPtr,
                                                             kCCKeySizeAES128,
                                                             NULL,
                                                             0,
                                                             0,
                                                             0,
                                                             &cryptor);

            if (result != kCCSuccess) {

                NSLog(@"encryptAESCTRData: createWithMode error: %@", @(result));
                result = CCCryptorRelease(cryptor);
                return nil;
            }
            size_t bufferLength = CCCryptorGetOutputLength(cryptor, [self length], true);
            NSMutableData *buffer = [NSMutableData dataWithLength:bufferLength];
            NSMutableData *cipherData = [NSMutableData data];

            size_t outLength;
            result = CCCryptorUpdate(cryptor,
                                     [self bytes],
                                     [self length],
                                     [buffer mutableBytes],
                                     [buffer length],
                                     &outLength);

            // FIXME: Release cryptor and return error
            if (result != kCCSuccess) {

                NSLog(@"encryptAESCTRData: CCCryptorUpdate error: %@", @(result));
                result = CCCryptorRelease(cryptor);
                return nil;
            }

            result = CCCryptorFinal(cryptor,
                                    [buffer mutableBytes],
                                    [buffer length],
                                    &outLength);

            // FIXME: Release cryptor and return error
            if (result != kCCSuccess) {

                NSLog(@"encryptAESCTRData: CCCryptorFinal error: %@", @(result));
                result = CCCryptorRelease(cryptor);
                return nil;
            }
           [cipherData appendBytes:buffer.bytes length:outLength];
           return cipherData;
           //return [NSData dataWithBytesNoCopy:(__bridge void * _Nonnull)(buffer) length:outLength freeWhenDone:YES];
        }

【问题讨论】：

当我在 CCCryptorCreateWithMode 方法中传递 ccPKCS7Padding 时，它会给出字符串 Encrypted Hex String == e8d1e4f9dd75ae80fb27d6a50e919a78 但使用 ccNoPadding 填充没有数据加密任何建议？

标签： ios objective-c encryption aes

【解决方案1】：

我用这个方法解决了

- (NSData *)AES128OperationWithEncriptionMode:(CCOperation)operation key:(NSData *)key iv:(NSData *)iv {


    CCCryptorRef cryptor = NULL;
    // 1. Create a cryptographic context.
    CCCryptorStatus status = CCCryptorCreateWithMode(operation, kCCModeCFB, kCCAlgorithmAES, ccNoPadding, [iv bytes], [key bytes], [key length], NULL, 0, 0, kCCModeOptionCTR_BE, &cryptor);

    NSAssert(status == kCCSuccess, @"Failed to create a cryptographic context.");

    NSMutableData *retData = [NSMutableData new];

    // 2. Encrypt or decrypt data.
    NSMutableData *buffer = [NSMutableData data];
    [buffer setLength:CCCryptorGetOutputLength(cryptor, [self length], true)]; // We'll reuse the buffer in -finish

    size_t dataOutMoved;
    status = CCCryptorUpdate(cryptor, self.bytes, self.length, buffer.mutableBytes, buffer.length, &dataOutMoved);
    NSAssert(status == kCCSuccess, @"Failed to encrypt or decrypt data");
    [retData appendData:[buffer subdataWithRange:NSMakeRange(0, dataOutMoved)]];

    // 3. Finish the encrypt or decrypt operation.
    status = CCCryptorFinal(cryptor, buffer.mutableBytes, buffer.length, &dataOutMoved);
    NSAssert(status == kCCSuccess, @"Failed to finish the encrypt or decrypt operation");
    [retData appendData:[buffer subdataWithRange:NSMakeRange(0, dataOutMoved)]];
    CCCryptorRelease(cryptor);

    return [retData copy];
}

【讨论】：