Question

在将Windows窗体应用程序从.NET 1.1框架升级到.NET 3.5框架时，我遇到了RSACryptoServiceProvider的问题。在数据库中，我存储了包含加密签名（SHA1哈希）的二进制文件，并且我将一个公钥存储在文件系统中，作为包含十六进制字符串的文本文档。从文件系统读取文件并将公钥编码到证书中时，我没有任何问题。

从公钥我得到模块和指数字段作为公钥的一部分。我将这些值分配给RSAParameters对象的新实例。接下来，我创建RSACryptoServiceProvider类的新实例并调用ImportParameters。在该调用中，3.5代码抛出异常。请注意，1.1代码完全没有问题。

有没有人知道是否需要转换给予RSAParameters属性的字节数组，所以我也可以在3.5代码中使用它们？我已经尝试将数组反转或将字节数组转换为BigInteger，但这并没有解决我的问题。

参考完整的堆栈跟踪：

System.Security.Cryptography.CryptographicException: Bad Data.

   at System.Security.Cryptography.CryptographicException.ThrowCryptogaphicException(Int32 hr)
   at System.Security.Cryptography.Utils._ImportKey(SafeProvHandle hCSP, Int32 keyNumber, CspProviderFlags flags, Object cspObject, SafeKeyHandle& hKey)
   at System.Security.Cryptography.RSACryptoServiceProvider.ImportParameters(RSAParameters parameters)

源代码，直到错误： // ------------------------------------------------ ------------------ * //验证证书。 * // ------------------------------------------------ ------------------ *

            // verify the CA certificate (output = public key van CA)
            byte[] lv_PkCA = VerifyCertificate(byte[], in_PkEUR);

            // verify the VU certificate (output = public key van VU)
            byte[] lv_PkVU = VerifyCertificate(byte[], lv_PkCA);


            //------------------------------------------------------------------
            // Verify the signatures
            //------------------------------------------------------------------

            // calculate hash with the SHA1 algorithm
            SHA1 lv_HashAlgoritm = new SHA1CryptoServiceProvider();

            byte[] lv_Modulus  = new byte[128];
            byte[] lv_Exponent = new byte[8];
            Buffer.BlockCopy(lv_PkVU, lv_PkVU.Length - 128 - 8, lv_Modulus , 0, lv_Modulus.Length);
            Buffer.BlockCopy(lv_PkVU, lv_PkVU.Length - 8      , lv_Exponent, 0, lv_Exponent.Length);

            // init RSA parameters
            RSAParameters lv_RSAKeyInfo = new RSAParameters();
            lv_RSAKeyInfo.Modulus  = lv_Modulus;
            lv_RSAKeyInfo.Exponent = lv_Exponent;

            // init RSA algoritme
            RSACryptoServiceProvider lv_RSA = new RSACryptoServiceProvider();
            lv_RSA.ImportParameters(lv_RSAKeyInfo);

有关更多参考，请参阅VerifyCertificate方法的内容。

private byte[] VerifyCertificate(
    byte[] in_Certificate,
    byte[] in_PublicKey)
{
    byte[] lv_CHR      = new byte[8];
    byte[] lv_Modulus  = new byte[128];
    byte[] lv_Exponent = new byte[8];
    Buffer.BlockCopy(in_PublicKey, in_PublicKey.Length - 128 - 8 - 8, lv_CHR     , 0, lv_CHR.Length);
    Buffer.BlockCopy(in_PublicKey, in_PublicKey.Length - 128 - 8    , lv_Modulus , 0, lv_Modulus.Length);
    Buffer.BlockCopy(in_PublicKey, in_PublicKey.Length - 8          , lv_Exponent, 0, lv_Exponent.Length);

    byte[] lv_Signature = new byte[128];
    byte[] lv_Cn        = new byte[58];
    byte[] lv_CAR       = new byte[8];
    Buffer.BlockCopy(in_Certificate,   0, lv_Signature, 0, lv_Signature.Length);
    Buffer.BlockCopy(in_Certificate, 128, lv_Cn       , 0, lv_Cn.Length);
    Buffer.BlockCopy(in_Certificate, 186, lv_CAR      , 0, lv_CAR.Length);

    for (int lv_Index = 0; lv_Index < lv_CAR.Length; lv_Index++)
    {
        if (lv_CAR[lv_Index] != lv_CHR[lv_Index])
            throw new Exception("Validation error: CAR not in public key.");
    }

    BigInteger lv_BiModulus   = new BigInteger(lv_Modulus);
    BigInteger lv_BiExponent  = new BigInteger(lv_Exponent);
    BigInteger lv_BiSignature = new BigInteger(lv_Signature);
    byte[] lv_Sr = lv_BiSignature.modPow(lv_BiExponent, lv_BiModulus).getBytes(lv_Signature.Length);

    if (lv_Sr.Length != 128)
        throw new Exception("The certificate coult not be validated: size of signature should be 128 bytes.");
    if ((lv_Sr[0]   != (byte)0x6A) ||
        (lv_Sr[127] != (byte)0xBC))
        throw new Exception("The certificate coult not be validated: invalid format.");

    byte[] lv_Cr = new byte[106];
    byte[] lv_H  = new byte[20];
    Buffer.BlockCopy(lv_Sr,   1, lv_Cr, 0, lv_Cr.Length);
    Buffer.BlockCopy(lv_Sr, 107, lv_H , 0, lv_H.Length);

    byte[] lv_C = new byte[164];
    Buffer.BlockCopy(lv_Cr, 0, lv_C,   0, lv_Cr.Length);
    Buffer.BlockCopy(lv_Cn, 0, lv_C, 106, lv_Cn.Length);

    // bereken de Hash van de public key
    SHA1CryptoServiceProvider lv_SHA1 = new SHA1CryptoServiceProvider();
    byte[] lv_Hash = lv_SHA1.ComputeHash(lv_C);

    // vergelijk de berekende hash met de hash in het certificaat
    if (lv_Hash.Length != lv_H.Length)
        throw new Exception("The certificate coult not be verified: hash length invalid.");
    for (int lv_Index = 0; lv_Index < lv_Hash.Length; lv_Index++)
    {
        if (lv_Hash[lv_Index] != lv_H[lv_Index])
            throw new DiantaException("The certificate coult not be verified: hash not invalid.");
    }

    return lv_C;
}

提前感谢您的帮助。

亲切的问候，

勒

Answer 1

指数可以有一个前置0，但不能有两个或更多。

您可能使用65537的指数（99％的RSA密钥对使用该指数），因此lv_RSAKeyInfo.Exponent为{0, 0, 0, 0, 0, 1, 0, 1}。

删除多余的零，您的代码应该可以正常工作。

RSACryptoServiceProvider.ImportParameters抛出System.Security.Cryptography.CryptographicException：错误数据

1 个答案: