Question

我需要使用我公司的数字证书签名并验证字符串。 VerifyHash（hash，CryptoConfig.MapNameToOID（“SHA1”），签名）;部分返回false，所以我得到“签名无效”错误。我究竟做错了什么？导致此错误的最可能原因是什么？

using System;
using System.Collections.Generic;
using System.Text;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;

namespace ConsoleApplication1
{
    class Program
    {
        static byte[] Sign(string text, string certSubject)
        {
            X509Store store = new X509Store(StoreName.My, StoreLocation.LocalMachine);
            X509Certificate2 myCert = null;
            RSACryptoServiceProvider provider = new RSACryptoServiceProvider();
            store.Open(OpenFlags.ReadOnly);
            foreach (X509Certificate2 cert in store.Certificates.Find(X509FindType.FindBySubjectName, certSubject, false))
            {
                myCert = cert;
                break;
            }
            store.Close();
            if (myCert == null)
            {
                throw new Exception("Certificate not found: " + certSubject, null);
            }
            // Hash the data
            SHA1Managed sha1 = new SHA1Managed();
            UnicodeEncoding encoding = new UnicodeEncoding();
            byte[] data = encoding.GetBytes(text);
            byte[] hash = sha1.ComputeHash(data);

            // Sign the hash
            return provider.SignHash(hash, CryptoConfig.MapNameToOID("SHA1"));
        }

        static bool Verify(string text, byte[] signature, string certPath)
        {
            // Load the certificate we'll use to verify the signature from a file 
            X509Certificate2 cert = new X509Certificate2(certPath);
            // Note: 
            // If we want to use the client cert in an ASP.NET app, we may use something like this instead:
            // X509Certificate2 cert = new X509Certificate2(Request.ClientCertificate.Certificate);

            // Get its associated CSP and public key
            RSACryptoServiceProvider csp = (RSACryptoServiceProvider)cert.PublicKey.Key;

            // Hash the data
            SHA1Managed sha1 = new SHA1Managed();
            UnicodeEncoding encoding = new UnicodeEncoding();
            byte[] data = encoding.GetBytes(text);
            byte[] hash = sha1.ComputeHash(data);

            // Verify the signature with the hash
            return csp.VerifyHash(hash, CryptoConfig.MapNameToOID("SHA1"), signature);
        }

        static void Main(string[] args)
        {
            // Usage sample
            try
            {
                // Sign text
                byte[] signature = Sign("Test 123", "Ross cert");

                // Verify signature. 
                if (Verify("Test 123", signature, @"C:\...RossTest.cer"))
                {
                    Console.WriteLine("SUCCESS! Signature verified");
                }
                else
                {
                    Console.WriteLine("ERROR: Signature not valid!");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("EXCEPTION: " + ex.Message);
            }
            Console.ReadKey();
        }
    }
}

Answer 1

我认为问题在于你的签名方法需要付出很多努力才能得到myCert但从不使用它。您只需使用新创建的未初始化RSACryptoServiceProvider进行签名。

我想在store.Close()行之后你需要以下内容：

RSACryptoServiceProvider provider = (RSACryptoServiceProvider)cert.PrivateKey;

Answer 2

RSACryptoServiceProvider provider = new RSACryptoServiceProvider();

这是签署数据时唯一分配provider的地方。该代码意味着您刚刚创建了一个全新的密钥对，即它与您查找的证书无关。

当您验证签名时，您正在使用证书的公钥（而不是您生成的密钥对中的公钥）。由于它们不匹配，因此您永远无法获得有效的签名验证。

以下您需要使用与证书关联的私钥进行签名，而不仅仅是任何密钥对。

验证签名 - 导致“签名无效”错误的原因是什么？

2 个答案: