阅读只有使用充气城堡PEM RSA公钥(Reading PEM RSA Public Key Onl

我想用C＃在读.pem只包含一个RSA公共密钥文件。 我没有访问私有密钥的信息，也没有我的应用程序需要它。 文件myprivatekey.pem文件开始

-----BEGIN PUBLIC KEY-----和结尾-----END PUBLIC KEY----- 。

我当前的代码如下：

    Org.BouncyCastle.Crypto.AsymmetricCipherKeyPair keyPair;

    using (var reader = File.OpenText(@"c:\keys\myprivatekey.pem"))
        keyPair = (Org.BouncyCastle.Crypto.AsymmetricCipherKeyPair)new Org.BouncyCastle.OpenSsl.PemReader(reader).ReadObject();

然而，代码引发InvalidCastException与该消息

无法投类型的对象Org.BouncyCastle.Crypto.Parameters.DsaPublicKeyParameters为键入“Org.BouncyCastle.Crypto.AsymmetricCipherKeyPair”。

我如何使用充气城堡的PemReader当没有私钥信息可用于只读公钥，？

Answer 1:

下面的代码将读取的公钥只给一个文件名。 异常处理应该改变任何生产代码。 该方法返回一个AsymetricKeyParameter 。

public Org.BouncyCastle.Crypto.AsymmetricKeyParameter ReadAsymmetricKeyParameter(string pemFilename)
{
    var fileStream = System.IO.File.OpenText (pemFilename);
    var pemReader = new Org.BouncyCastle.OpenSsl.PemReader (fileStream);
    var KeyParameter = (Org.BouncyCastle.Crypto.AsymmetricKeyParameter)pemReader.ReadObject ();
    return KeyParameter;
}

Answer 2:

这里有一个可能的解决方案，它读取公共和私人PEM文件到的RSACryptoServiceProvider：

public class PemReaderB
{
    public static RSACryptoServiceProvider GetRSAProviderFromPem(String pemstr)
    {
        CspParameters cspParameters = new CspParameters();
        cspParameters.KeyContainerName = "MyKeyContainer";
        RSACryptoServiceProvider rsaKey = new RSACryptoServiceProvider(cspParameters);

        Func<RSACryptoServiceProvider, RsaKeyParameters, RSACryptoServiceProvider> MakePublicRCSP = (RSACryptoServiceProvider rcsp, RsaKeyParameters rkp) =>
        {
            RSAParameters rsaParameters = DotNetUtilities.ToRSAParameters(rkp);
            rcsp.ImportParameters(rsaParameters);
            return rsaKey;
        };

        Func<RSACryptoServiceProvider, RsaPrivateCrtKeyParameters, RSACryptoServiceProvider> MakePrivateRCSP = (RSACryptoServiceProvider rcsp, RsaPrivateCrtKeyParameters rkp) =>
        {
            RSAParameters rsaParameters = DotNetUtilities.ToRSAParameters(rkp);
            rcsp.ImportParameters(rsaParameters);
            return rsaKey;
        };

        PemReader reader = new PemReader(new StringReader(pemstr));
        object kp = reader.ReadObject();

        // If object has Private/Public property, we have a Private PEM
        return (kp.GetType().GetProperty("Private") != null) ? MakePrivateRCSP(rsaKey, (RsaPrivateCrtKeyParameters)(((AsymmetricCipherKeyPair)kp).Private)) : MakePublicRCSP(rsaKey, (RsaKeyParameters)kp);
    }

    public static RSACryptoServiceProvider GetRSAProviderFromPemFile(String pemfile)
    {
        return GetRSAProviderFromPem(File.ReadAllText(pemfile).Trim());
    }
}

希望这可以帮助别人。

Answer 3:

在回答c0d3Junk13，我有一个PEM私钥同样的问题，我花了一下午找到使用C＃BouncyCastle的版本1.7和Visual Studio 2013的桌面快车解决方案。 不要忘记添加项目引用BouncyCastle.Crypto.dll

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Collections;
using System.IO;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Asn1.Pkcs;
using Org.BouncyCastle.Crypto.Digests;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Crypto.Signers;
using Org.BouncyCastle.X509;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Math.EC;
using Org.BouncyCastle.Utilities.Collections;
using Org.BouncyCastle.Utilities.Encoders;
using Org.BouncyCastle.Crypto; 
using Org.BouncyCastle.Crypto.Engines; 
using Org.BouncyCastle.OpenSsl;

/* 
    For an Active Directory generated pem, strip out everything in pem file before line:
    "-----BEGIN PRIVATE KEY-----" and re-save.
*/
string privateKeyFileName = @"C:\CertificateTest\CS\bccrypto-net-1.7-bin\private_key3.pem";

TextReader reader = File.OpenText(privateKeyFileName);

Org.BouncyCastle.Crypto.Parameters.RsaPrivateCrtKeyParameters key;

using (reader = File.OpenText(privateKeyFileName))
{
    key = (Org.BouncyCastle.Crypto.Parameters.RsaPrivateCrtKeyParameters)new PemReader(reader).ReadObject();
}

cipher.Init(false, key);

//Decrypting the input bytes

byte[] decipheredBytes = cipher.ProcessBlock(cipheredBytes, 0, cipheredBytes.Length);

MessageBox.Show(Encoding.UTF8.GetString(decipheredBytes));

Answer 4:

试试下面的代码：

Using Org.BouncyCastle.Crypto;


string path = HttpContext.Current.Server.MapPath(@"~\key\ABCD.pem");



AsymmetricCipherKeyPair Key;

TextReader tr = new StreamReader(@path);

 PemReader pr = new PemReader(tr);
        Key = (AsymmetricCipherKeyPair)pr.ReadObject();
        pr.Reader.Close();
        tr.Close();



         AsymmetricKeyParameter keaa = Key.Public;

文章来源: Reading PEM RSA Public Key Only using Bouncy Castle