目前最流行的加密算法莫过于RSA了，以下是我们.net/.net core C#生成环境用的RSA加密工具类，在此分享给大家。
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
namespace Common
{
/// <summary>
/// RSA加密工具类
/// </summary>
public class RSACryptoUtil
{
/// <summary>
/// rsa私钥
/// </summary>
private static readonly RSACryptoServiceProvider _privateKeyRsaProvider;
/// <summary>
/// rsa公钥
/// </summary>
private static readonly RSACryptoServiceProvider _publicKeyRsaProvider;
static RSACryptoUtil()
{
//string root = AppDomain.CurrentDomain.RelativeSearchPath;
string publicKey = @"MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAqc7Mgsct5yaU+Ihxwz28luI/0xJe/uZQPwkMyOJpz+tDi5p9V0JYaYg3SrhIqkNQFluBBSRCnp1NNzfT3qUn93eJ1g9/8wwBloiK+W0s6DuSQj93+T8ZM1+qnnBOUiNrHBmynjR1frN4CJVmdXP1+w3CqLoMaHkw46Vy5UvEf9yedetjcCwIbmjRJzE2Mv3qQz67HbgQIDAQAB";//File.ReadAllText($"公钥位置", Encoding.ASCII);
string privateKey = @"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";//File.ReadAllText($"私钥位置", Encoding.ASCII);
if (!string.IsNullOrWhiteSpace(publicKey))
{
_publicKeyRsaProvider = CreateRsaProviderFromPublicKey(publicKey);
}
if (!string.IsNullOrWhiteSpace(privateKey))
{
_privateKeyRsaProvider = CreateRsaProviderFromPrivateKey(privateKey);
}
}
/// <summary>
/// 解密
/// </summary>
/// <param name="cipherText"></param>
/// <returns></returns>
public static string Decrypt(string cipherText)
{
if (_privateKeyRsaProvider == null)
{
LogUtil.Logger.Error("_privateKeyRsaProvider is null");
return string.Empty;
}
try
{
return Encoding.UTF8.GetString(_privateKeyRsaProvider.Decrypt(Convert.FromBase64String(cipherText), false));
}
catch (Exception ex)
{
LogUtil.Logger.Error(ex, $"RSA解密失败：{cipherText}");
return string.Empty;
}
}
/// <summary>
/// 加密
/// </summary>
/// <param name="text"></param>
/// <returns></returns>
public static string Encrypt(string text)
{
if (_publicKeyRsaProvider == null)
{
LogUtil.Logger.Error("_publicKeyRsaProvider is null");
return string.Empty;
}
return Convert.ToBase64String(_publicKeyRsaProvider.Encrypt(Encoding.UTF8.GetBytes(text), false));
}
/// <summary>
/// 创建rsa公钥对象
/// </summary>
/// <param name="publicKeyString"></param>
/// <returns></returns>
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 = Convert.FromBase64String(publicKeyString);
// --------- 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
{
ushort 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;
byte[] 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;
byte 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 = 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;
}
}
}
/// <summary>
/// 创建rsa私钥对象
/// </summary>
/// <param name="privateKey"></param>
/// <returns></returns>
private static RSACryptoServiceProvider CreateRsaProviderFromPrivateKey(string privateKey)
{
var privateKeyBits = Convert.FromBase64String(privateKey);
var RSA = new RSACryptoServiceProvider();
var RSAparams = new RSAParameters();
using (BinaryReader binr = new BinaryReader(new MemoryStream(privateKeyBits)))
{
ushort twobytes = binr.ReadUInt16();
if (twobytes == 0x8130) binr.ReadByte();
else if (twobytes == 0x8230) binr.ReadInt16();
else throw new Exception("Unexpected value read binr.ReadUInt16()");
twobytes = binr.ReadUInt16();
if (twobytes != 0x0102) throw new Exception("Unexpected version");
byte bt = binr.ReadByte();
if (bt != 0x00) throw new Exception("Unexpected value read binr.ReadByte()");
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)
{
int count;
byte bt = binr.ReadByte();
if (bt != 0x02) return 0;
bt = binr.ReadByte();
if (bt == 0x81) count = binr.ReadByte();
else if (bt == 0x82)
{
byte highbyte = binr.ReadByte();
byte 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;
}
}
}
以上公钥私钥不可用，如需生成请使用“支付宝开放平台密钥工具”，官方下载链接：密钥工具下载 - 支付宝文档中心 (alipay.com)
以下是工具使用步骤：
第一步：选择RSA2算法，生成密钥
第二步：复制公钥，直接赋值给工具类变量“publicKey”，复制私钥，进行下一步使用
第三步：到“格式转换”栏，把私钥粘贴到“应用私钥”，点击“转换”，我们可以看到下边有“PKCS1”字样，这就是.net环境中RSA算法支持的私钥格式，复制“输出”，赋值给“privateKey”即可。
以上就是工具使用步骤，快来用最安全的对称加密算法加密你的内容吧！