PHP phpseclib与C# RSA签名验证互操作指南

//Load private key
$rsa = PublicKeyLoader::load("... private key ...", false);

//Set PKCS1 mode
$rsa->withPadding(RSA::ENCRYPTION_PKCS1 | RSA::SIGNATURE_PKCS1)->withHash("sha256");

//Generate and Convert the hash from 64 byte hex to 32 byte
$hash = pack("H*", hash("sha256", "test"));

//Sign the hash and encode it
$signed_hash = base64_encode($rsa->sign($hash));

//Encode the hash
$hash = base64_encode($hash);

<?php
require_once 'vendor/autoload.php'; // 确保引入phpseclib

use phpseclib3\Crypt\RSA;
use phpseclib3\Crypt\PublicKeyLoader;

// 假设私钥文件路径或内容
$privateKeyContent = file_get_contents('private_key.pem'); 

// 加载私钥
$rsa = PublicKeyLoader::load($privateKeyContent, false);

// 设置PKCS#1 v1.5签名填充模式和SHA256哈希算法
// 注意：withPadding会返回一个新的实例，需要重新赋值
// RSA::ENCRYPTION_PKCS1在签名场景中是无效的，应移除
$rsa = $rsa->withPadding(RSA::SIGNATURE_PKCS1)->withHash("sha256");

// phpseclib的sign方法会隐式哈希，因此直接传入原始数据
$dataToSign = "test";
$signature = $rsa->sign($dataToSign);

// 对签名结果进行Base64编码以便传输
$base64Signature = base64_encode($signature);

echo "原始数据: " . $dataToSign . PHP_EOL;
echo "Base64编码的签名: " . $base64Signature . PHP_EOL;
?>

static void Main()
{
    //Create a new instance of RSA.
    using (RSA rsa = RSA.Create())
    {
        //Load public key from XML string
        rsa.FromXmlString("... public key ...");

        //Create an RSAPKCS1SignatureDeformatter object and pass it the RSA instance
        //to transfer the key information.
        RSAPKCS1SignatureDeformatter RSADeformatter = new RSAPKCS1SignatureDeformatter(rsa);
        RSADeformatter.SetHashAlgorithm("SHA256");

        //decode the hash
        var hash = Convert.FromBase64String("SHA256 Hash As Base64");
        var signedHash = Convert.FromBase64String("SHA256 Hash Signature As Base64");

        //Verify the hash and display the results to the console.
        if (RSADeformatter.VerifySignature(hash, signedHash))
        {
            Console.WriteLine("True");
        }
        else
        {
            Console.WriteLine("False");
        }
    }
}

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

public class RsaSignatureVerifier
{
    public static void Main(string[] args)
    {
        // 从PHP端获取的Base64编码签名
        // 替换为实际从PHP输出的Base64编码签名
        string base64SignatureFromPhp = "your_base64_encoded_signature_from_php_here"; 

        // 原始数据，必须与PHP端签名时使用的数据一致
        string dataToVerify = "test";

        // 假设公钥内容，通常从文件加载或配置中读取
        // 确保公钥格式与rsa.FromXmlString兼容
        // 示例：<RSAKeyValue><Modulus>...</Modulus><Exponent>...</Exponent></RSAKeyValue>
        string publicKeyXml = "<RSAKeyValue><Modulus>...</Modulus><Exponent>...</Exponent></RSAKeyValue>";

        using (RSA rsa = RSA.Create())
        {
            // 加载公钥
            rsa.FromXmlString(publicKeyXml);

            // 创建RSAPKCS1SignatureDeformatter对象并传递RSA实例
            RSAPKCS1SignatureDeformatter RSADeformatter = new RSAPKCS1SignatureDeformatter(rsa);

            // 设置哈希算法，必须与PHP端签名时使用的哈希算法一致
            RSADeformatter.SetHashAlgorithm("SHA256");

            // 在C#端显式计算原始数据的SHA256哈希值
            // 必须与PHP端签名时使用的原始数据和哈希算法完全一致
            byte[] hashOfDataToVerify = SHA256.Create().ComputeHash(Encoding.UTF8.GetBytes(dataToVerify));

            // 解码从PHP端接收到的Base64编码签名
            byte[] signatureBytes = Convert.FromBase64String(base64SignatureFromPhp);

            // 验证签名
            if (RSADeformatter.VerifySignature(hashOfDataToVerify, signatureBytes))
            {
                Console.WriteLine("签名验证成功！");
            }
            else
            {
                Console.WriteLine("签名验证失败！");
            }
        }
    }
}