ASP.NET Core RSA加密或解密

加密解密 ASP.NETCore · 發表 2018-10-26 07:44:00

摘要：前言這兩天主要是公司同事用到了RSA加密，事後也看了下，以為很簡單，最終利用RSACryptoServiceProvider來實現RSA加密，然後大致瞭解到RSACryptoServiceProvider不支援跨平臺，此類原先存在於.NET Framework中，本文我講講利用RSA.C...

前言

這兩天主要是公司同事用到了RSA加密，事後也看了下，以為很簡單，最終利用RSACryptoServiceProvider來實現RSA加密，然後大致瞭解到RSACryptoServiceProvider不支援跨平臺，此類原先存在於.NET Framework中，本文我講講利用RSA.Create來實現各種加密模式統一封裝。

RSA加密或解密

主要是在查詢資料時看到了dudu老大寫的有關RSA加密的文章（ ofollow,noindex">http://www.cnblogs.com/dudu/p/dotnet-core-rsa-openssl.html ），剛好找到了我們專案中需要用到的openssl加密模式對應.NET Core中的Pkcs1，這裡實現程式碼實在有點多，然後自己也遇到如評論中所說加密長度超出的情況，這個時候只能採取分段加密的方式。接下來我們來看看。首先看看如下程式碼：

var privateKey = "<RSAKeyValue><Modulus>0wE26IHp4U9OLtPhJ+fT8ej6aWORFP8pd++MjUuhkQQm/zhcImbxQbjxtSAftz+kkDwGDFJpSldQPyigOGcUx7PofTc6VhiFik9E9SsxV9n0iEEtqUndDfmBJfPAWt+4UDMwKakgZqFoapDuwjKlTErFvKCyKCs+qN9OZvZwKWk=</Modulus><Exponent>AQAB</Exponent><P>8Ei6NIsZtgV3DQjuGHfGLS6o1O+IUXxzjqLxdMm77yhEPUxR9YPIxODJ2VVTddXSAHxViJJt30yJ7JhVz6cpQw==</P><Q>4M49NrmalgVQFMsea2RMB1qN8fAPfIw5G9q9hzsLcWSCmkeRRIQlvPYflVEKAYKiDVVzENETbnnduFXWBABx4w==</Q><DP>t+JQbemN0Zi5FQaif6MZzHYKynpNTl75aE0Wj5Pa+RlNr8N6bXNe8Bw/HM2Jw4HQ5oJASvYUk3DVlHS4JuP8VQ==</DP><DQ>lT62iv9brp9mU/epgVh71SH8PJPIZEJfo6tryjyb0zMMNcqvmZI1z6aCv0mm3+vPFBUXqCF1yhFj7n4l8FAvSw==</DQ><InverseQ>flrvgxHvf4l+fdymEVDgKjsfGqshOpppoNgZj9kpeWBto3o8z++Ki6eSLQT3nVnpx2QCZeTWkxTED4nhSLKscw==</InverseQ><D>cQTCg1Eqk7sltmFYxUYgOP/AOPjSufteG9acYwYymPkvZh6rAuY+rSRBmvGE62NUYskzuB/gM6iG2/2HrA5SixfNgCvZ+nsK+kX5pzQRsYdD71ViQW0hOanXwj45I2zHRgBiuTtCUP0fs5pISmQkaeJkDL5pO2l+wvlgl+wunj0=</D></RSAKeyValue>";
var publicKey = "<RSAKeyValue><Modulus>0wE26IHp4U9OLtPhJ+fT8ej6aWORFP8pd++MjUuhkQQm/zhcImbxQbjxtSAftz+kkDwGDFJpSldQPyigOGcUx7PofTc6VhiFik9E9SsxV9n0iEEtqUndDfmBJfPAWt+4UDMwKakgZqFoapDuwjKlTErFvKCyKCs+qN9OZvZwKWk=</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>";

using (var rsa = RSA.Create())
{
rsa.FromXmlString(publicKey);
}

經到github上查詢解決方案，我們需要手動設定值，如下：

public static void FromXmlString(RSA rsa, string xmlString)
{
RSAParameters parameters = new RSAParameters();

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml(xmlString);

if (xmlDoc.DocumentElement.Name.Equals("RSAKeyValue"))
{
foreach (XmlNode node in xmlDoc.DocumentElement.ChildNodes)
{
switch (node.Name)
{
case "Modulus": parameters.Modulus = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
case "Exponent": parameters.Exponent = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
case "P": parameters.P = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
case "Q": parameters.Q = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
case "DP": parameters.DP = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
case "DQ": parameters.DQ = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
case "InverseQ": parameters.InverseQ = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
case "D": parameters.D = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
}
}
}
else
{
throw new Exception("Invalid XML RSA key.");
}

rsa.ImportParameters(parameters);
}

其中經過很多嘗試，要麼是Base64格式不正確，要麼是待解密的資料長度和Key Size無效，我第一次嘗試是返回的加密字串，然後進行解密，就是有問題，最後還是返回位元組陣列來進行加密和解密，直接看程式碼，這裡解決了加密資料長度超出問題以及各種加密模式的統一，如下RSAHelper。

public static class RSAHelper
{
private const string privateKey = "<RSAKeyValue><Modulus>0wE26IHp4U9OLtPhJ+fT8ej6aWORFP8pd++MjUuhkQQm/zhcImbxQbjxtSAftz+kkDwGDFJpSldQPyigOGcUx7PofTc6VhiFik9E9SsxV9n0iEEtqUndDfmBJfPAWt+4UDMwKakgZqFoapDuwjKlTErFvKCyKCs+qN9OZvZwKWk=</Modulus><Exponent>AQAB</Exponent><P>8Ei6NIsZtgV3DQjuGHfGLS6o1O+IUXxzjqLxdMm77yhEPUxR9YPIxODJ2VVTddXSAHxViJJt30yJ7JhVz6cpQw==</P><Q>4M49NrmalgVQFMsea2RMB1qN8fAPfIw5G9q9hzsLcWSCmkeRRIQlvPYflVEKAYKiDVVzENETbnnduFXWBABx4w==</Q><DP>t+JQbemN0Zi5FQaif6MZzHYKynpNTl75aE0Wj5Pa+RlNr8N6bXNe8Bw/HM2Jw4HQ5oJASvYUk3DVlHS4JuP8VQ==</DP><DQ>lT62iv9brp9mU/epgVh71SH8PJPIZEJfo6tryjyb0zMMNcqvmZI1z6aCv0mm3+vPFBUXqCF1yhFj7n4l8FAvSw==</DQ><InverseQ>flrvgxHvf4l+fdymEVDgKjsfGqshOpppoNgZj9kpeWBto3o8z++Ki6eSLQT3nVnpx2QCZeTWkxTED4nhSLKscw==</InverseQ><D>cQTCg1Eqk7sltmFYxUYgOP/AOPjSufteG9acYwYymPkvZh6rAuY+rSRBmvGE62NUYskzuB/gM6iG2/2HrA5SixfNgCvZ+nsK+kX5pzQRsYdD71ViQW0hOanXwj45I2zHRgBiuTtCUP0fs5pISmQkaeJkDL5pO2l+wvlgl+wunj0=</D></RSAKeyValue>";
private const string publicKey = "<RSAKeyValue><Modulus>0wE26IHp4U9OLtPhJ+fT8ej6aWORFP8pd++MjUuhkQQm/zhcImbxQbjxtSAftz+kkDwGDFJpSldQPyigOGcUx7PofTc6VhiFik9E9SsxV9n0iEEtqUndDfmBJfPAWt+4UDMwKakgZqFoapDuwjKlTErFvKCyKCs+qN9OZvZwKWk=</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>";

public static byte[] Encrypt(byte[] encryptBytes, RSAEncryptionPadding padding)
{
using (var rsa = RSA.Create())
{

FromXmlString(rsa, publicKey);

var maxBlockSize = GetMaxBlockSize(rsa, padding);

if (encryptBytes.Length <= maxBlockSize)
{
var @bytes = rsa.Encrypt(encryptBytes, padding);
return @bytes;
}

using (var memoryStream = new MemoryStream(encryptBytes))
{
using (var readStream = new MemoryStream())
{
byte[] buffer = new byte[maxBlockSize];

int blockSize = memoryStream.Read(buffer, 0, maxBlockSize);

while (blockSize > 0)
{
var blockByte = new byte[blockSize];

Array.Copy(buffer, 0, blockByte, 0, blockSize);

var encrypts = rsa.Encrypt(blockByte, padding);

readStream.Write(encrypts, 0, encrypts.Length);

blockSize = memoryStream.Read(buffer, 0, maxBlockSize);
}

return readStream.ToArray();
}
}
}
}

public static byte[] Decrypt(byte[] decryptBytes, RSAEncryptionPadding padding)
{
using (var rsa = RSA.Create())
{
FromXmlString(rsa, privateKey);

var maxBlockSize = rsa.KeySize / 8;

if (decryptBytes.Length <= maxBlockSize)
{
var @bytes = rsa.Decrypt(decryptBytes, padding);
return @bytes;
}

using (var memoryStream = new MemoryStream(decryptBytes))
{
using (var readStream = new MemoryStream())
{
var buffer = new byte[maxBlockSize];

var blockSize = memoryStream.Read(buffer, 0, maxBlockSize);

while (blockSize > 0)
{
var blockByte = new byte[blockSize];

Array.Copy(buffer, 0, blockByte, 0, blockSize);

var decrypts = rsa.Decrypt(blockByte, padding);

readStream.Write(decrypts, 0, decrypts.Length);

blockSize = memoryStream.Read(buffer, 0, maxBlockSize);
}

return readStream.ToArray();
}
}
}
}

public static void FromXmlString(RSA rsa, string xmlString)
{
RSAParameters parameters = new RSAParameters();

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml(xmlString);

if (xmlDoc.DocumentElement.Name.Equals("RSAKeyValue"))
{
foreach (XmlNode node in xmlDoc.DocumentElement.ChildNodes)
{
switch (node.Name)
{
case "Modulus": parameters.Modulus = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
case "Exponent": parameters.Exponent = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
case "P": parameters.P = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
case "Q": parameters.Q = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
case "DP": parameters.DP = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
case "DQ": parameters.DQ = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
case "InverseQ": parameters.InverseQ = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
case "D": parameters.D = (string.IsNullOrEmpty(node.InnerText) ? null : Convert.FromBase64String(node.InnerText)); break;
}
}
}
else
{
throw new Exception("Invalid XML RSA key.");
}

rsa.ImportParameters(parameters);
}

static int GetMaxBlockSize(RSA rsa, RSAEncryptionPadding padding)
{
var offset = 0;
if (padding.Mode == RSAEncryptionPaddingMode.Pkcs1)
{
offset = 11;
}
else
{
if (padding.Equals(RSAEncryptionPadding.OaepSHA1))
{
offset = 42;
}

if (padding.Equals(RSAEncryptionPadding.OaepSHA256))
{
offset = 66;
}

if (padding.Equals(RSAEncryptionPadding.OaepSHA384))
{
offset = 98;
}

if (padding.Equals(RSAEncryptionPadding.OaepSHA512))
{
offset = 130;
}
}
return rsa.KeySize / 8 - offset;
}
}

我們開始進行如下測試，加密資料長度為6890，如下。

static void Main(string[] args)
{
var encryptString = "0";
for (int i = 1; i < 2000; i++)
{
encryptString += i;
}

Console.WriteLine(encryptString.Length);

var encryptBytes = Encoding.UTF8.GetBytes(encryptString);

//加密後位元組陣列
var resultBytes = RSAHelper.Encrypt(encryptBytes, RSAEncryptionPadding.Pkcs1);

//解密後位元組陣列
var decryptBytes = RSAHelper.Decrypt(resultBytes, RSAEncryptionPadding.Pkcs1);

//解密結果
var result = Encoding.UTF8.GetString(decryptBytes);

//比較加密字串和解密結果是否相等
Console.WriteLine(encryptString == result);
Console.ReadKey();
}

總結

本文通過實現RSA加密和解密，同時也對加密資料超出採取分段加密的方式，測試在windows上通過，由於沒有linux和mac環境未經測試，不知是否好使，一試見分曉。

ASP.NET Core RSA加密或解密

前言

RSA加密或解密

總結

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