C# Net 使用 RSA 加密解密 OpenSSL 生成的密码

C# Net 使用 RSA 加密解密 OpenSSL 生成的密码

有时候回得到如下的公钥

-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDNwWw9Ae1b+hZmDbheF5Zel25i
D6tlta9.......
-----END PUBLIC KEY-----

或者私钥

-----BEGIN RSA PRIVATE KEY-----
MIICXgIBAAKBgQDNwWw9Ae1b+hZmDbheF5Zel25iD6tlta9nYDal2ex/Blsy9Utb
EKYoUrZjR.....
-----END RSA PRIVATE KEY-----

C#的RSA：

https://www.cnblogs.com/duanjt/p/11061380.html

RSA 的 OpenSSL 介绍：

https://www.codeproject.com/Articles/25487/Cryptographic-Interoperability-Keys

此博文参考文章：

https://www.cnblogs.com/lidj/p/5220816.html

在线测试RSA：

http://www.metools.info/code/c81.html

正式代码，我们使用下面的方式转换

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace Ping.CryptologyHelp
{
    /// <summary>
    /// RSA 密码（OpenSSL方式）
    /// </summary>
    public class RSAOpenSSLCryptology
    {
        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="text"></param>
        /// <returns></returns>
        public static string Encrypt(string text, string publicKey = null)
        {
            var _publicKeyRsaProvider = CreateRsaProviderFromPublicKey(publicKey);

            return Convert.ToBase64String(_publicKeyRsaProvider.Encrypt(Encoding.UTF8.GetBytes(text), false));
        }

        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="text"></param>
        /// <returns></returns>
        public static string Decrypt(string text, string privateKey = null)
        {
            var _privateKeyRsaProvider = CreateRsaProviderFromPrivateKey(privateKey);

            return Encoding.UTF8.GetString(_privateKeyRsaProvider.Decrypt(System.Convert.FromBase64String(text), false));
        }

        private static RSACryptoServiceProvider CreateRsaProviderFromPublicKey(string publicKeyString)
        {
            // encoded OID sequence for  PKCS #1 rsaEncryption szOID_RSA_RSA = "1.2.840.113549.1.1.1"
            byte[] SeqOID = { 0x30, 0x0D, 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x01, 0x01, 0x05, 0x00 };
            byte[] x509key;
            byte[] seq = new byte[15];
            int x509size;

            x509key = Convert.FromBase64String(publicKeyString);
            x509size = x509key.Length;

            // ---------  Set up stream to read the asn.1 encoded SubjectPublicKeyInfo blob  ------
            using (MemoryStream mem = new MemoryStream(x509key))
            {
                using (BinaryReader binr = new BinaryReader(mem))  //wrap Memory Stream with BinaryReader for easy reading
                {
                    byte bt = 0;
                    ushort twobytes = 0;

                    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;

                    seq = binr.ReadBytes(15);       //read the Sequence OID
                    if (!CompareBytearrays(seq, SeqOID))    //make sure Sequence for OID is correct
                        return null;

                    twobytes = binr.ReadUInt16();
                    if (twobytes == 0x8103) //data read as little endian order (actual data order for Bit String is 03 81)
                        binr.ReadByte();    //advance 1 byte
                    else if (twobytes == 0x8203)
                        binr.ReadInt16();   //advance 2 bytes
                    else
                        return null;

                    bt = binr.ReadByte();
                    if (bt != 0x00)     //expect null byte next
                        return null;

                    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();
                    byte lowbyte = 0x00;
                    byte highbyte = 0x00;

                    if (twobytes == 0x8102) //data read as little endian order (actual data order for Integer is 02 81)
                        lowbyte = binr.ReadByte();  // read next bytes which is bytes in modulus
                    else if (twobytes == 0x8202)
                    {
                        highbyte = binr.ReadByte(); //advance 2 bytes
                        lowbyte = binr.ReadByte();
                    }
                    else
                        return null;
                    byte[] modint = { lowbyte, highbyte, 0x00, 0x00 };   //reverse byte order since asn.1 key uses big endian order
                    int modsize = BitConverter.ToInt32(modint, 0);

                    int firstbyte = binr.PeekChar();
                    if (firstbyte == 0x00)
                    {   //if first byte (highest order) of modulus is zero, don't include it
                        binr.ReadByte();    //skip this null byte
                        modsize -= 1;   //reduce modulus buffer size by 1
                    }

                    byte[] modulus = binr.ReadBytes(modsize);   //read the modulus bytes

                    if (binr.ReadByte() != 0x02)            //expect an Integer for the exponent data
                        return null;
                    int expbytes = (int)binr.ReadByte();        // should only need one byte for actual exponent data (for all useful values)
                    byte[] exponent = binr.ReadBytes(expbytes);

                    // ------- create RSACryptoServiceProvider instance and initialize with public key -----
                    RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
                    RSAParameters RSAKeyInfo = new RSAParameters();
                    RSAKeyInfo.Modulus = modulus;
                    RSAKeyInfo.Exponent = exponent;
                    RSA.ImportParameters(RSAKeyInfo);

                    return RSA;
                }

            }
        }

        private static RSACryptoServiceProvider CreateRsaProviderFromPrivateKey(string privateKey)
        {
            var privateKeyBits = System.Convert.FromBase64String(privateKey);

            var RSA = new RSACryptoServiceProvider();
            var RSAparams = new RSAParameters();

            using (BinaryReader binr = new BinaryReader(new MemoryStream(privateKeyBits)))
            {
                byte bt = 0;
                ushort twobytes = 0;
                twobytes = binr.ReadUInt16();
                if (twobytes == 0x8130)
                    binr.ReadByte();
                else if (twobytes == 0x8230)
                    binr.ReadInt16();
                else
                    throw new Exception("执行 binr.ReadUInt16() 失败");

                twobytes = binr.ReadUInt16();
                if (twobytes != 0x0102)
                    throw new Exception("错误的版本");

                bt = binr.ReadByte();
                if (bt != 0x00)
                    throw new Exception("执行 binr.ReadByte() 失败");

                RSAparams.Modulus = binr.ReadBytes(GetIntegerSize(binr));
                RSAparams.Exponent = binr.ReadBytes(GetIntegerSize(binr));
                RSAparams.D = binr.ReadBytes(GetIntegerSize(binr));
                RSAparams.P = binr.ReadBytes(GetIntegerSize(binr));
                RSAparams.Q = binr.ReadBytes(GetIntegerSize(binr));
                RSAparams.DP = binr.ReadBytes(GetIntegerSize(binr));
                RSAparams.DQ = binr.ReadBytes(GetIntegerSize(binr));
                RSAparams.InverseQ = binr.ReadBytes(GetIntegerSize(binr));
            }

            RSA.ImportParameters(RSAparams);
            return RSA;
        }

        private static int GetIntegerSize(BinaryReader binr)
        {
            byte bt = 0;
            byte lowbyte = 0x00;
            byte highbyte = 0x00;
            int count = 0;
            bt = binr.ReadByte();
            if (bt != 0x02)
                return 0;
            bt = binr.ReadByte();

            if (bt == 0x81)
                count = binr.ReadByte();
            else
                if (bt == 0x82)
            {
                highbyte = binr.ReadByte();
                lowbyte = binr.ReadByte();
                byte[] modint = { lowbyte, highbyte, 0x00, 0x00 };
                count = BitConverter.ToInt32(modint, 0);
            }
            else
            {
                count = bt;
            }

            while (binr.ReadByte() == 0x00)
            {
                count -= 1;
            }
            binr.BaseStream.Seek(-1, SeekOrigin.Current);
            return count;
        }

        private static bool CompareBytearrays(byte[] a, byte[] b)
        {
            if (a.Length != b.Length)
                return false;
            int i = 0;
            foreach (byte c in a)
            {
                if (c != b[i])
                    return false;
                i++;
            }
            return true;
        }
    }
}

　　

调用方式如下：（需要去掉 -----BEGIN xxx KEY----- ）

            var aaa = RSAOpenSSLCryptology.Encrypt("", @"MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDNwWw9Ae1b+hZmDbheF5Zel25i
D6tlta9.......");