通过.NET实现文件数字签名的标准化方法

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

public static RSA GenerateRSAKeyPair()
{
    RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(2048);
    return rsa;
}

public static byte[] SignFile(string filePath, RSA rsa)
{
    using (FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read))
    {
        byte[] fileData = new byte[fileStream.Length];
        fileStream.Read(fileData, 0, fileData.Length);

        using (SHA256 sha256 = SHA256.Create())
        {
            byte[] hash = sha256.ComputeHash(fileData);
            return rsa.SignHash(hash, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
        }
    }
}

public static bool VerifyFile(string filePath, byte[] signature, RSA rsa)
{
    using (FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read))
    {
        byte[] fileData = new byte[fileStream.Length];
        fileStream.Read(fileData, 0, fileData.Length);

        using (SHA256 sha256 = SHA256.Create())
        {
            byte[] hash = sha256.ComputeHash(fileData);
            return rsa.VerifyHash(hash, signature, HashAlgorithmName.SHA256, RSASignaturePadding.Pkcs1);
        }
    }
}

RSA rsa = GenerateRSAKeyPair();

string filePath = "example.txt";
byte[] signature = SignFile(filePath, rsa);

bool isValid = VerifyFile(filePath, signature, rsa);

if (isValid)
{
    Console.WriteLine("文件签名验证通过");
}
else
{
    Console.WriteLine("文件签名验证失败");
}