无法使用使用Java加密的Obj-C对AES数据进行解密

Question

我一直试图解密服务器发送给我的应用的一些AES加密数据。

为了提炼出问题，我写了一个模拟服务器在做什么的小型java程序。它使用AES加密一些测试数据然后将它编码为Base64：

AesCipherService cipherService = new AesCipherService(); 
cipherService.setKeySize(128); 

String stringKey = "2EE1F10212ADD4BE"; 
byte[] keyAsBytes = stringKey.getBytes(); 

String text = "text to encrypt"; 
byte[] encryptedBytes = cipherService.encrypt(text.getBytes(), keyAsBytes).getBytes(); 
String base64String  = Base64.encodeToString(encryptedBytes); 
System.out.println(base64String); 

// Reverse the process to check can retrieve "text to encrypt": 
byte[] bytesToDecode = Base64.decode(base64String); 
byte[] decryptedBytes = cipherService.decrypt(bytesToDecode, keyAsBytes).getBytes();   
String decryptedString = new String(decryptedBytes); 
System.out.println(decryptedString); 

当运行此是输出：

R5UBpP30YjX9Ae2HoPb2Rrfi5rQJY2d0ac1 + zaIX5A4 =

文本加密

所以我可以成功地加密数据，打印出来。然后，如果我解密它显示原始文本，所以这里的一切工作正常。

现在这里是我的Obj-C代码，我试图解密从Java代码加密的数据。我已经复制/从NetBeans IDE输出窗口粘贴的加密数据作为OBJ-C内容的源数据进行解密：

- (void) decryptData 
{ 
    NSData* dataToDecrypt  = [[NSData alloc] initWithBase64EncodedString: @"R5UBpP30YjX9Ae2HoPb2Rrfi5rQJY2d0ac1+zaIX5A4=" options: 0]; 
    NSString* key    = @"2EE1F10212ADD4BE"; 

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

    NSUInteger dataLength = [dataToDecrypt length]; 
    size_t bufferSize = dataLength + kCCBlockSizeAES128; 
    void *buffer = malloc(bufferSize); 

    size_t numBytesDecrypted = 0; 
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, 
              kCCAlgorithmAES, 
              kCCOptionPKCS7Padding, 
              keyPtr, 
              kCCBlockSizeAES128, 
              keyPtr, 
              [dataToDecrypt bytes], 
              dataLength, 
              buffer, 
              bufferSize, 
              &numBytesDecrypted); 
    if (cryptStatus == kCCSuccess) { 
     NSLog(@"Success"); 
     NSData* unencryptedData = [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted]; 
     Byte *unencryptedAsBytes = (Byte*)malloc(unencryptedData.length); 
     memcpy(unencryptedAsBytes, [unencryptedData bytes], unencryptedData.length); 
     NSString *decryptedString = [NSString stringWithUTF8String:[unencryptedData bytes]]; 
     NSLog(@"%@", decryptedString); 
    } 
} 

当该运行状态是kCCSuccess和numBytesDecrypted是32（同由于数据长度），但解密的字符串不是 “文本加密”，decryptedString是零，如果在Xcode的控制台I PO unencryptedAsBytes它会显示这样的：

“\一条Y | \ 376 \ 347cD * \ 320NC \ X14 \ x91C \ x88 \ 301 \ 341z \ xaca \ x11 \ 371

任何想法这里有什么问题？

Answer 1

Java加密代码生成一个随机IV，并以它为前缀加密。为了将解密的IV从加密中分离出来。

在十六进制：

key:  32454531463130323132414444344245 
iv:  479501A4FDF46235FD01ED87A0F6F646 (first 16 binary bytes of the full encryption) 
encrypted: B7E2E6B40963677469CD7ECDA217E40E (rest of binary bytes of the full encryption) 
decrypted: 7465787420746F20656E6372797074 

代码：

NSData* fullEncrypted  = [[NSData alloc] initWithBase64EncodedString: @"R5UBpP30YjX9Ae2HoPb2Rrfi5rQJY2d0ac1+zaIX5A4=" options: 0]; 
NSData *ivData = [fullEncrypted subdataWithRange:NSMakeRange(0, kCCBlockSizeAES128)]; 
NSData *encryptedData = [fullEncrypted subdataWithRange:NSMakeRange(kCCBlockSizeAES128, fullEncrypted.length-kCCBlockSizeAES128)]; 
NSLog(@"ivData:   %@", ivData); 
NSLog(@"encryptedData: %@", encryptedData); 

NSData *keyData = [@"2EE1F10212ADD4BE" dataUsingEncoding:NSUTF8StringEncoding]; 
NSLog(@"keyData:   %@", keyData); 

NSMutableData *unencryptedData = [NSMutableData dataWithLength:encryptedData.length]; 
size_t numBytesDecrypted = 0; 
CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, 
             kCCAlgorithmAES, 
             kCCOptionPKCS7Padding, 
             keyData.bytes, keyData.length, 
             ivData.bytes, 
             encryptedData.bytes, encryptedData.length, 
             unencryptedData.mutableBytes, unencryptedData.length, 
             &numBytesDecrypted); 
if (cryptStatus == kCCSuccess) { 
    NSLog(@"Success"); 

    unencryptedData.length = numBytesDecrypted; 
    NSLog(@"unencryptedData: %@", unencryptedData); 

    NSString *decryptedString = [[NSString alloc] initWithData:unencryptedData encoding:NSUTF8StringEncoding]; 
    NSLog(@"decryptedString: %@", decryptedString); 
} 

输出：

ivData:   479501a4 fdf46235 fd01ed87 a0f6f646 
encryptedData: b7e2e6b4 09636774 69cd7ecd a217e40e 
keyData:   32454531 46313032 31324144 44344245 
Success 
unencryptedData: 74657874 20746f20 656e6372 79707400 
decryptedString: text to encrypt