Question

我知道这是一个与this one类似的问题，但在我走下Bouncey Castle路线之前，是否有人知道是否可以从.pem文件加载RSA KeyPair，例如：

直接使用.NET 3.5加密库而无需参加第三方或自己滚动？

Answer 1

http://www.jensign.com/opensslkey/index.html

来源http://www.jensign.com/opensslkey/opensslkey.cs 更新：此网址不再提供源代码。现在可以在https://gist.github.com/stormwild/7887264或https://web.archive.org/web/20170731015547/http://www.jensign.com/opensslkey/opensslkey.cs找到它。

编辑：摘录相关代码：

首先，在---- BEGIN ----和---- END ----部分之间提取文本，并将base64解码为字节数组（详见上面的链接），然后传递它来：

//------- Parses binary ans.1 RSA private key; returns RSACryptoServiceProvider  ---
public static RSACryptoServiceProvider DecodeRSAPrivateKey(byte[] privkey)
{
    byte[] MODULUS, E, D, P, Q, DP, DQ, IQ ;

// ---------  Set up stream to decode the asn.1 encoded RSA private key  ------
    MemoryStream  mem = new MemoryStream(privkey) ;
    BinaryReader binr = new BinaryReader(mem) ;    //wrap Memory Stream with BinaryReader for easy reading
    byte bt = 0;
    ushort twobytes = 0;
    int elems = 0;
    try {
        twobytes = binr.ReadUInt16();
        if (twobytes == 0x8130) //data read as little endian order (actual data order for Sequence is 30 81)
            binr.ReadByte();    //advance 1 byte
        else if (twobytes == 0x8230)
            binr.ReadInt16();   //advance 2 bytes
        else
            return null;

        twobytes = binr.ReadUInt16();
        if (twobytes != 0x0102) //version number
            return null;
        bt = binr.ReadByte();
        if (bt !=0x00)
            return null;


//------  all private key components are Integer sequences ----
        elems = GetIntegerSize(binr);
        MODULUS = binr.ReadBytes(elems);

        elems = GetIntegerSize(binr);
        E = binr.ReadBytes(elems) ;

        elems = GetIntegerSize(binr);
        D = binr.ReadBytes(elems) ;

        elems = GetIntegerSize(binr);
        P = binr.ReadBytes(elems) ;

        elems = GetIntegerSize(binr);
        Q = binr.ReadBytes(elems) ;

        elems = GetIntegerSize(binr);
        DP = binr.ReadBytes(elems) ;

        elems = GetIntegerSize(binr);
        DQ = binr.ReadBytes(elems) ;

        elems = GetIntegerSize(binr);
        IQ = binr.ReadBytes(elems) ;

        Console.WriteLine("showing components ..");
        if (verbose) {
            showBytes("\nModulus", MODULUS) ;
            showBytes("\nExponent", E);
            showBytes("\nD", D);
            showBytes("\nP", P);
            showBytes("\nQ", Q);
            showBytes("\nDP", DP);
            showBytes("\nDQ", DQ);
            showBytes("\nIQ", IQ);
        }

// ------- create RSACryptoServiceProvider instance and initialize with public key -----
        RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
        RSAParameters RSAparams = new RSAParameters();
        RSAparams.Modulus =MODULUS;
        RSAparams.Exponent = E;
        RSAparams.D = D;
        RSAparams.P = P;
        RSAparams.Q = Q;
        RSAparams.DP = DP;
        RSAparams.DQ = DQ;
        RSAparams.InverseQ = IQ;
        RSA.ImportParameters(RSAparams);
        return RSA;
    }
    catch (Exception) {
        return null;
    }
    finally {
        binr.Close();
    }
}

Answer 2

我已经创建了一个小帮助NuGet包来创建基于公钥和私有（rsa）密钥的X509证书。

请参阅NuGet和Github-project了解基于opensslkey的功能和代码示例。

使用.NET加密库在c＃中使用.pem文件中的私钥解密

2 个答案: