三重DES解密密钥无效,16字节 [英] Triple DES decryption invalid key with 16 bytes
问题描述
我有一个Android项目中,我得到一个三重DES加密的一段文字,从我的Web服务。我需要三重DES解密。
I have an android project in which am getting an Triple DES encrypted piece of text from my web services. I need to Triple DES decrypt.
不过,我收到无效键例外。我的键转换为十六进制格式,我得到了一个错误: W / System.err的:java.security.InvalidKeyException:DES密钥过长 - 应该是8个字节
我发现< A HREF =https://community.oracle.com/thread/1528631相对=nofollow>这里一个论坛,并解释说,十六进制可能会导致问题
However, I am getting invalid key exceptions. My key is converted to HEX format and I got an error: W/System.err﹕ java.security.InvalidKeyException: DES key too long - should be 8 bytes
I found here a forum explaining that hex may cause issue
DES密钥是56位的8个字节通常包装,以便有机会,在16字节/字符,他们给你的十六进制EN codeD字节的关键。你可以得到一个十六进制德codeR的
所以,我用我的转换十六进制字符串为一个字节数组
So I converted my hex string to a byte array using
private static byte[] hexStringtoByteArray(String hex){
int len = hex.length();
byte [] data = new byte[len/2];
for(int i=0; i<len;i+=2){
data[i/2] = (byte)((Character.digit(hex.charAt(i), 16)<<4) + Character.digit(hex.charAt(i+1),16));
}
return data;
}
和通过了到密码,我得到一个错误:
and passed that in to the cipher and I get an error:
W/System.err﹕ java.security.InvalidKeyException
W/System.err﹕ at javax.crypto.spec.DESedeKeySpec.
这是我的解密方法。我想AP preciate如果有人能照到的地方,我可能会错误的一些情况。
here is my decrypt method. I would appreciate if someone could shine some light on where I might be going wrong.
public String DesDecryptPin(String pin, String encryptKey) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException, UnsupportedEncodingException {
String UNICODE_FORMAT = "UTF8";
String decryptedPinText = null;
byte[] hexConvert = hexStringtoByteArray(encryptKey);
SecretKey desKey = null;
KeySpec desKeySpec = new DESedeKeySpec(hexConvert); // Exception HERE
Cipher desCipher;
SecretKeyFactory skf = SecretKeyFactory.getInstance("DESede");
desCipher = Cipher.getInstance("DES/ECB/NoPadding");
try {
desKey = skf.generateSecret(desKeySpec);
} catch (InvalidKeySpecException e) {
e.printStackTrace();
}
desCipher.init(Cipher.DECRYPT_MODE, desKey);
byte[] decryptPin = desCipher.doFinal(pin.getBytes());
decryptedPinText = new String(decryptPin, "UTF-8");
return decryptedPinText;
}
我的关键是C9AF269DF8A78A06D1216BFFF8F0536A。
My key is C9AF269DF8A78A06D1216BFFF8F0536A.
我已经检查与客户和键是正确的,所以相同的密钥被用于加密。的
加密code 的
Encryption Code
public string TripleDESEncrypt(string strClearText, string strKey)
{
byte[] bytClearText;
byte[] bytClearTextChunk = new byte[8];
byte[] bytEncryptedChunk = new byte[8];
int BytesCount = 0;
int nArrayPosition = 0;
string strEncryptedChar;
string strEncryptedText = "";
ArrayList Input = new ArrayList();
ArrayList Output = new ArrayList();
TripleDESCryptoServiceProvider tdes = (TripleDESCryptoServiceProvider)TripleDESCryptoServiceProvider.Create();
tdes.Key = HexToByteArray(strKey);
tdes.Mode = CipherMode.ECB;
ICryptoTransform tdesEncrypt = tdes.CreateEncryptor();
bytClearText = ASCIIEncoding.ASCII.GetBytes(strClearText);
BytesCount = bytClearText.Length;
for (int i = 0; i < BytesCount; i++)
{
if (nArrayPosition == 8)
{
Input.Add(bytClearTextChunk);
bytClearTextChunk = new byte[8];
nArrayPosition = 0;
}
bytClearTextChunk[nArrayPosition] = bytClearText[i];
nArrayPosition++;
}
if (nArrayPosition != 0)
Input.Add(bytClearTextChunk);
foreach (byte[] Cbyte in Input)
{
tdesEncrypt.TransformBlock(Cbyte, 0, 8, bytEncryptedChunk, 0);
Output.Add(bytEncryptedChunk);
bytEncryptedChunk = null;
bytEncryptedChunk = new byte[8];
}
foreach (byte[] Cbyte in Output)
{
foreach (byte BByte in Cbyte)
{
strEncryptedChar = BByte.ToString("X");
strEncryptedChar = strEncryptedChar.PadLeft(2, Convert.ToChar("0"));
strEncryptedText += strEncryptedChar;
}
}
return strEncryptedText;
}
下面是解密文本的14个字符的例子:12345678901234
Here is an example of the decrypted text with 14 chars: 12345678901234
推荐答案
您实例化你的密码为(辛格运河)DES密码有:
You instantiate your Cipher as a (singel) DES Cipher with:
desCipher = Cipher.getInstance("DES/ECB/NoPadding");
但你的关键是 16个字节 3DES键,thuse你的错误
But your key is a 16 byte 3Des key, and thuse you get the error
DES key too long - should be 8 bytes
尝试实例化你的密码作为3DES加密使用:
Try instantiating your cipher as a 3DES cipher with:
desCipher = Cipher.getInstance("DESede/ECB/NoPadding");
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