c# RSA相关 加密 签名 PEM - XML互相转换

安装nuget Portable.BouncyCastle

using Org.BouncyCastle.Asn1.Pkcs;
using Org.BouncyCastle.Asn1.X509;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Pkcs;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.X509;
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
using System.Xml;

public class RSAHelper
{
    /// <summary>
    /// 生成公钥与私钥方法
    /// </summary>
    /// <returns></returns>
    public static string[] CreateKey(KeyType keyType, KeySize keySize)
    {
        try
        {
            string[] sKeys = new string[2];
            RSACryptoServiceProvider rsa = new RSACryptoServiceProvider((int)keySize);
            switch (keyType)
            {
                case KeyType.XML:
                    {
                        //私钥
                        sKeys[0] = rsa.ToXmlString(true);
                        //公钥
                        sKeys[1] = rsa.ToXmlString(false);
                    }
                    break;
                case KeyType.PKS8:
                    {
                        sKeys[0] = rsa.ToXmlString(true);
                        //公钥
                        sKeys[1] = rsa.ToXmlString(false);

                        //JAVA私钥
                        sKeys[0] = RSAPrivateKeyDotNet2Java(sKeys[0]);
                        //JAVA公钥
                        sKeys[1] = RSAPublicKeyDotNet2Java(sKeys[1]);
                    }
                    break;
                default:
                    break;
            }
            return sKeys;
        }
        catch (Exception ex)
        {
            return null;
        }
    }

    /// <summary>
    /// 密钥类型
    /// </summary>
    public enum KeyType
    {
        /// <summary>
        /// xml类型
        /// </summary>
        XML,

        /// <summary>
        /// pks8类型
        /// </summary>
        PKS8
    }

    /// <summary>
    /// 密钥尺寸(一般都是1024位的)
    /// </summary>
    public enum KeySize
    {
        SMALL = 1024,
        BIG = 2048
    }


    /// <summary>
    /// RSA私钥格式转换，.net->java
    /// </summary>
    /// <param name="privateKey">.net生成的私钥</param>
    /// <returns></returns>
    public static string RSAPrivateKeyDotNet2Java(string privateKey)
    {
        XmlDocument doc = new XmlDocument();
        doc.LoadXml(privateKey);
        BigInteger m = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Modulus")[0].InnerText));
        BigInteger exp = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Exponent")[0].InnerText));
        BigInteger d = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("D")[0].InnerText));
        BigInteger p = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("P")[0].InnerText));
        BigInteger q = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Q")[0].InnerText));
        BigInteger dp = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("DP")[0].InnerText));
        BigInteger dq = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("DQ")[0].InnerText));
        BigInteger qinv = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("InverseQ")[0].InnerText));

        RsaPrivateCrtKeyParameters privateKeyParam = new RsaPrivateCrtKeyParameters(m, exp, d, p, q, dp, dq, qinv);

        PrivateKeyInfo privateKeyInfo = PrivateKeyInfoFactory.CreatePrivateKeyInfo(privateKeyParam);
        byte[] serializedPrivateBytes = privateKeyInfo.ToAsn1Object().GetEncoded();
        return Convert.ToBase64String(serializedPrivateBytes);

    }

    /// <summary>
    /// RSA公钥格式转换，.net->java
    /// </summary>
    /// <param name="publicKey">.net生成的公钥</param>
    /// <returns></returns>
    public static string RSAPublicKeyDotNet2Java(string publicKey)
    {
        XmlDocument doc = new XmlDocument();
        doc.LoadXml(publicKey);
        BigInteger m = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Modulus")[0].InnerText));
        BigInteger p = new BigInteger(1, Convert.FromBase64String(doc.DocumentElement.GetElementsByTagName("Exponent")[0].InnerText));
        RsaKeyParameters pub = new RsaKeyParameters(false, m, p);

        SubjectPublicKeyInfo publicKeyInfo = SubjectPublicKeyInfoFactory.CreateSubjectPublicKeyInfo(pub);
        byte[] serializedPublicBytes = publicKeyInfo.ToAsn1Object().GetDerEncoded();
        return Convert.ToBase64String(serializedPublicBytes);
    }


    /// <summary>
    /// RSA私钥格式转换，java->.net
    /// </summary>
    /// <param name="privateKey">java生成的RSA私钥</param>
    /// <returns></returns>
    public static string RSAPrivateKeyJavaToDotNet(string privateKey)
    {
        RsaPrivateCrtKeyParameters privateKeyParam = (RsaPrivateCrtKeyParameters)PrivateKeyFactory.CreateKey(Convert.FromBase64String(privateKey));

        return string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent><P>{2}</P><Q>{3}</Q><DP>{4}</DP><DQ>{5}</DQ><InverseQ>{6}</InverseQ><D>{7}</D></RSAKeyValue>",
            Convert.ToBase64String(privateKeyParam.Modulus.ToByteArrayUnsigned()),
            Convert.ToBase64String(privateKeyParam.PublicExponent.ToByteArrayUnsigned()),
            Convert.ToBase64String(privateKeyParam.P.ToByteArrayUnsigned()),
            Convert.ToBase64String(privateKeyParam.Q.ToByteArrayUnsigned()),
            Convert.ToBase64String(privateKeyParam.DP.ToByteArrayUnsigned()),
            Convert.ToBase64String(privateKeyParam.DQ.ToByteArrayUnsigned()),
            Convert.ToBase64String(privateKeyParam.QInv.ToByteArrayUnsigned()),
            Convert.ToBase64String(privateKeyParam.Exponent.ToByteArrayUnsigned()));

    }

    /// <summary>
    /// RSA公钥格式转换，java->.net
    /// </summary>
    /// <param name="publicKey">java生成的公钥</param>
    /// <returns></returns>
    public static string RSAPublicKeyJavaToDotNet(string publicKey)
    {
        RsaKeyParameters publicKeyParam = (RsaKeyParameters)PublicKeyFactory.CreateKey(Convert.FromBase64String(publicKey));
        return string.Format("<RSAKeyValue><Modulus>{0}</Modulus><Exponent>{1}</Exponent></RSAKeyValue>",
            Convert.ToBase64String(publicKeyParam.Modulus.ToByteArrayUnsigned()),
            Convert.ToBase64String(publicKeyParam.Exponent.ToByteArrayUnsigned()));
    }


    /// <summary>
    /// 最大加密长度
    /// </summary>
    private const int MAX_ENCRYPT_BLOCK = 245;

    /// <summary>
    /// 最大解密长度
    /// </summary>
    private const int MAX_DECRYPT_BLOCK = 256;


    /// <summary>
    /// 用私钥给数据进行RSA加密
    /// </summary>
    /// <param name="xmlPrivateKey"></param>
    /// <param name="strEncryptString"></param>
    /// <returns></returns>
    public static string PrivateKeyEncrypt(string xmlPrivateKey, string strEncryptString)
    {
        //加载私钥
        RSACryptoServiceProvider privateRsa = new RSACryptoServiceProvider();
        privateRsa.FromXmlString(xmlPrivateKey);

        //转换密钥
        AsymmetricCipherKeyPair keyPair = DotNetUtilities.GetKeyPair(privateRsa);
        IBufferedCipher c = CipherUtilities.GetCipher("RSA/ECB/PKCS1Padding"); //使用RSA/ECB/PKCS1Padding格式

        c.Init(true, keyPair.Private);//第一个参数为true表示加密，为false表示解密；第二个参数表示密钥
        byte[] dataToEncrypt = Encoding.UTF8.GetBytes(strEncryptString);//获取字节

        byte[] cache;
        int time = 0;//次数
        int inputLen = dataToEncrypt.Length;
        int offSet = 0;

        MemoryStream outStream = new MemoryStream();
        while (inputLen - offSet > 0)
        {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK)
            {
                cache = c.DoFinal(dataToEncrypt, offSet, MAX_ENCRYPT_BLOCK);
            }
            else
            {
                cache = c.DoFinal(dataToEncrypt, offSet, inputLen - offSet);
            }
            //写入
            outStream.Write(cache, 0, cache.Length);

            time++;
            offSet = time * MAX_ENCRYPT_BLOCK;
        }

        byte[] resData = outStream.ToArray();

        string strBase64 = Convert.ToBase64String(resData);
        outStream.Close();
        return strBase64;
    }

    /// <summary>
    /// 用公钥给数据进行RSA解密 
    /// </summary>
    /// <param name="xmlPublicKey"> 公钥(XML格式字符串) </param>
    /// <param name="strDecryptString"> 要解密数据 </param>
    /// <returns> 解密后的数据 </returns>
    public static string PublicKeyDecrypt(string xmlPublicKey, string strDecryptString)
    {
        //加载公钥
        RSACryptoServiceProvider publicRsa = new RSACryptoServiceProvider();
        publicRsa.FromXmlString(xmlPublicKey);
        RSAParameters rp = publicRsa.ExportParameters(false);

        //转换密钥
        AsymmetricKeyParameter pbk = DotNetUtilities.GetRsaPublicKey(rp);

        IBufferedCipher c = CipherUtilities.GetCipher("RSA/ECB/PKCS1Padding");
        //第一个参数为true表示加密，为false表示解密；第二个参数表示密钥
        c.Init(false, pbk);

        byte[] DataToDecrypt = Convert.FromBase64String(strDecryptString);

        byte[] cache;
        int time = 0;//次数
        int inputLen = DataToDecrypt.Length;
        int offSet = 0;
        MemoryStream outStream = new MemoryStream();
        while (inputLen - offSet > 0)
        {
            if (inputLen - offSet > MAX_DECRYPT_BLOCK)
            {
                cache = c.DoFinal(DataToDecrypt, offSet, MAX_DECRYPT_BLOCK);
            }
            else
            {
                cache = c.DoFinal(DataToDecrypt, offSet, inputLen - offSet);
            }
            //写入
            outStream.Write(cache, 0, cache.Length);

            time++;
            offSet = time * MAX_DECRYPT_BLOCK;
        }
        byte[] resData = outStream.ToArray();

        string strDec = Encoding.UTF8.GetString(resData);
        return strDec;
    }

    /// <summary>
    /// 签名
    /// </summary>
    /// <param name="str">需签名的数据</param>
    /// <returns>签名后的值</returns>
    public static string Sign(string str, string privateKey, SignAlgType signAlgType)
    {
        //根据需要加签时的哈希算法转化成对应的hash字符节
        byte[] bt = Encoding.GetEncoding("utf-8").GetBytes(str);
        byte[] rgbHash = null;
        switch (signAlgType)
        {
            case SignAlgType.SHA256:
                {
                    SHA256CryptoServiceProvider csp = new SHA256CryptoServiceProvider();
                    rgbHash = csp.ComputeHash(bt);
                }
                break;
            case SignAlgType.MD5:
                {
                    MD5CryptoServiceProvider csp = new MD5CryptoServiceProvider();
                    rgbHash = csp.ComputeHash(bt);
                }
                break;
            case SignAlgType.SHA1:
                {
                    SHA1 csp = new SHA1CryptoServiceProvider();
                    rgbHash = csp.ComputeHash(bt);
                }
                break;
            default:
                break;
        }
        RSACryptoServiceProvider key = new RSACryptoServiceProvider();
        key.FromXmlString(privateKey);
        RSAPKCS1SignatureFormatter formatter = new RSAPKCS1SignatureFormatter(key);
        formatter.SetHashAlgorithm(signAlgType.ToString());//此处是你需要加签的hash算法，需要和上边你计算的hash值的算法一致，不然会报错。
        byte[] inArray = formatter.CreateSignature(rgbHash);
        return Convert.ToBase64String(inArray);
    }

    /// <summary>
    /// 签名验证
    /// </summary>
    /// <param name="str">待验证的字符串</param>
    /// <param name="sign">加签之后的字符串</param>
    /// <returns>签名是否符合</returns>
    public static bool Verify(string str, string sign, string publicKey, SignAlgType signAlgType)
    {
        byte[] bt = Encoding.GetEncoding("utf-8").GetBytes(str);
        byte[] rgbHash = null;
        switch (signAlgType)
        {
            case SignAlgType.SHA256:
                {
                    SHA256CryptoServiceProvider csp = new SHA256CryptoServiceProvider();
                    rgbHash = csp.ComputeHash(bt);
                }
                break;
            case SignAlgType.MD5:
                {
                    MD5CryptoServiceProvider csp = new MD5CryptoServiceProvider();
                    rgbHash = csp.ComputeHash(bt);
                }
                break;
            case SignAlgType.SHA1:
                {
                    SHA1 csp = new SHA1CryptoServiceProvider();
                    rgbHash = csp.ComputeHash(bt);
                }
                break;
            default:
                break;
        }
        RSACryptoServiceProvider key = new RSACryptoServiceProvider();
        key.FromXmlString(publicKey);
        RSAPKCS1SignatureDeformatter deformatter = new RSAPKCS1SignatureDeformatter(key);
        deformatter.SetHashAlgorithm(signAlgType.ToString());
        byte[] rgbSignature = Convert.FromBase64String(sign);
        if (deformatter.VerifySignature(rgbHash, rgbSignature))
            return true;
        return false;
    }

    /// <summary>
    /// 签名算法类型
    /// </summary>
    public enum SignAlgType
    {
        /// <summary>
        /// sha256
        /// </summary>
        SHA256,

        /// <summary>
        /// md5
        /// </summary>
        MD5,

        /// <summary>
        /// sha1
        /// </summary>
        SHA1
    }
}

使用方式如下

 var pubkeyPEM = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA3XwdOA766g5nSgCrbt71kNs569Wk7a10BSwDMD0VzpiUyVvyRHV03Lo7dq7VwNtMZNh3d7kYOI5r/BnoO/zldBkl7hwyffjPWsLtzlZ7aKQdJuPynIL7+5iBhtiA2XSCJxD0MZq2wuMEl8h9V4bK3YjCUG17wX9BbGP6fk+CPkDdISVagQNXuIWzadmVLH+5aamE6E/CaAGSUBEIl2E1j9OXokhdCKP7IuFAIHFpzbNacp0baa5UZPGnuyJyjtJk9aa+yweAc41I37l7S3bmHaoG7nkpNivIWnS7B6zgI044Ptc7kwhTWBiZd3Q4CUnf1ZR1zRj19GhLfxTvLa6vBwIDAQAB";
            var privatekeyPEM = "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";

            var xmlPrivateKey = RSAHelper.RSAPrivateKeyJavaToDotNet(privatekeyPEM);
            var xmlPublicKey = RSAHelper.RSAPublicKeyJavaToDotNet(pubkeyPEM);

            var secret = RSAHelper.PrivateKeyEncrypt(xmlPrivateKey, "test");
            var raw = RSAHelper.PublicKeyDecrypt(xmlPublicKey, secret);

            var auth = RSAHelper.Sign(secret, xmlPrivateKey, RSAHelper.SignAlgType.MD5);
            var authRaw = RSAHelper.Verify(secret, auth, xmlPublicKey, RSAHelper.SignAlgType.MD5);