C#.NET 国密 BASE64编码的私钥提取16进制私钥

C#.NET 国密 BASE64编码的私钥提取16进制私钥，

从BASE64编码的公钥中提取16进制字符串公钥，

 从BASE64编码的私钥中提取16进制字符串私钥，

 锦州银行在使用这种私钥 。

String mchtPubKey = "MFkwEwYHKoZIzj0CAQYIKoEcz1UBgi0DQgAElmWpvTHHsQEUMSLoMcDssXAjCkdgjCkncPXNnnapIEkSXAYZMV7/f0ba+b/VKsZTRgvZ2InkxSRLFHVznnf1lg==";
                String mchtPriKey = "MIGTAgEAMBMGByqGSM49AgEGCCqBHM9VAYItBHkwdwIBAQQgGKTw1sFkats23rL373anMYL+r1dlIv1MWor8PCIqrmugCgYIKoEcz1UBgi2hRANCAASWZam9McexARQxIugxwOyxcCMKR2CMKSdw9c2edqkgSRJcBhkxXv9/Rtr5v9UqxlNGC9nYieTFJEsUdXOed/WW";

String bankSm2PublicKey = SM2ExtUtil.GetPublicKey(bankPubKey);
                Console.WriteLine("公钥16进制字符串:" + bankSm2PublicKey);
                String bankSm2PrivateKey = SM2ExtUtil.GetPrivateKey(bankPriKey);
                Console.WriteLine("私钥16进制字符串:" + bankSm2PrivateKey);

工具类SM2ExtUtil：

需要nuget 引用 BouncyCastle，搜索 Portable.BouncyCastle 。

using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Utilities.Encoders;
using System;

namespace CommonUtils
{
    public static class SM2ExtUtil
    {
        /// <summary>
        /// 从BASE64编码的公钥中提取16进制字符串公钥
        /// </summary>
        /// <param name="publicKeyBase64"></param>
        /// <returns></returns>
        public static String GetPublicKey(String publicKeyBase64)
        {
            var pubkey1=  ((ECPublicKeyParameters)PublicKeyFactory.CreateKey(Convert.FromBase64String(publicKeyBase64))).Q.GetEncoded();
            //把公钥的04截取掉，只保留后128位。
            var pubkey2 = Hex.ToHexString(pubkey1).Substring(2).ToUpper();
            return pubkey2;
        }

        /// <summary>
        /// 从BASE64编码的私钥中提取16进制字符串私钥
        /// </summary>
        /// <param name="PrivateKeyBase64"></param>
        /// <returns></returns>
        public static String GetPrivateKey(String PrivateKeyBase64)
        {
            var bankPriKey1 = ((ECPrivateKeyParameters)PrivateKeyFactory.CreateKey(Convert.FromBase64String(PrivateKeyBase64))).D.ToByteArray();
            var bankPriKey2 = Hex.ToHexString(bankPriKey1).ToUpper();
            return bankPriKey2;
        }
    }
}

--

如果你只需要 AsymmetricKeyParameter 对象：

AsymmetricKeyParameter mchtPubKeyObj = PublicKeyFactory.CreateKey(Convert.FromBase64String(mchtPubKeyBase64));

AsymmetricKeyParameter objPrivateKey = PrivateKeyFactory.CreateKey(Convert.FromBase64String(privateKeyBase64));