使用CryptoJS的base64密钥在iOS上进行AES加密

时间:2017-08-28 22:29:46

标签: ios objective-c encryption aes cryptojs

我使用CryptoJS生成和导出密钥:

const password = crypto.lib.WordArray.random(128 / 8);
const salt = crypto.lib.WordArray.random(128 / 8);
const encryptionKey = crypto.PBKDF2(password, salt, {keySize: 128 / 32});
return encryptionKey.toString();

现在我尝试使用iOS上的密钥加密某些数据:

const char *s = [encryptionKey cStringUsingEncoding:NSASCIIStringEncoding];
NSData *keyData= [NSData dataWithBytes:s length:strlen(s)];

NSMutableData *ivData = [NSMutableData dataWithLength:kCCBlockSizeAES128];
SecRandomCopyBytes(kSecRandomDefault, kCCBlockSizeAES128, ivData.mutableBytes);
NSData *iv = [NSData dataWithData:ivData];

size_t outLength;

NSMutableData *cipherData = [NSMutableData dataWithLength:dataString.length + kCCBlockSizeAES128];
CCCrypt(kCCEncrypt, // operation
    kCCAlgorithmAES128, // Algorithm
    kCCOptionPKCS7Padding, // options
    keyData.bytes, // key
    keyData.length, // keylength
    iv.bytes,// iv
    jsonData.bytes, // dataIn
    jsonData.length, // dataInLength,
    cipherData.mutableBytes, // dataOut
    cipherData.length, // dataOutAvailable
    &outLength); // dataOutMoved

    cipherData.length = outLength;

NSString *cipherText = [cipherData base64EncodedStringWithOptions:NSUTF8StringEncoding];
NSString *ivText = [iv base64EncodedStringWithOptions:NSUTF8StringEncoding];

return [ivText stringByAppendingString:cipherText]

到目前为止这一切都有效。然而,尝试使用CryptoJS解密数据失败了:

const iv = crypto.enc.Base64.parse(message.substr(0, 24));
const encrypted = crypto.enc.Base64.parse(message.substring(24));

const decrypted = crypto.AES.decrypt(encrypted, encryptionKey, {
  iv: iv,
  padding: crypto.pad.Pkcs7,
  mode: crypto.mode.CBC
});
console.log(decrypted.toString(crypto.enc.Utf8))

问题似乎在于将密钥从CryptoJS传递到iOS。传递给CCCrypt的正确格式是什么?

2 个答案:

答案 0 :(得分:1)

base64EncodedStringWithOptions的选项不正确,会将行结尾字符添加到Base64编码的iv和加密数据中。

您不需要行结尾选项,默认情况下,不会插入行结尾。只需指定0

NSString *cipherText = [cipherData base64EncodedStringWithOptions:0];
NSString *ivText = [iv base64EncodedStringWithOptions:0];

选项请注意,NSUTF8StringEncoding不是方法base64EncodedStringWithOptions的编码选项。选项包括:

NSDataBase64Encoding64CharacterLineLength
NSDataBase64Encoding76CharacterLineLength
NSDataBase64EncodingEndLineWithCarriageReturn
NSDataBase64EncodingEndLineWithLineFeed`

这些都是行分隔符选项。

答案 1 :(得分:0)

我的原始代码包含三个错误。

  1. 生成的字符串需要使用zaph:

    建议的无参数进行编码
    NSString *cipherText = [cipherData base64EncodedStringWithOptions:0];
    NSString *ivText = [iv base64EncodedStringWithOptions:0];
    
  2. 要将加密密钥正确转换为NSData,我使用here提供的方法并将其称为:

    NSData *keyData= [self dataFromHexString:encryptionKey];
    
  3. CryptoJS的decrypt函数需要这样的对象:

    const encrypted = crypto.enc.Base64.parse(message.substring(24));
    
    const params = {
      ciphertext: encrypted,
      salt: ''
    };
    
    const decrypted = crypto.AES.decrypt(params, crypto.enc.Hex.parse(this.encryptionKey.toString()), {
      iv: iv,
      padding: crypto.pad.Pkcs7,
      mode: crypto.mode.CBC
    });
    
    return decrypted.toString(crypto.enc.Utf8);
    
  4. 感谢您的帮助!