我得到这个错误:

根据验证过程,远端证书无效。

每当我试图在我的c#代码中使用Gmail的SMTP服务器发送电子邮件时。 有人能给我指出解决这个问题的正确方向吗?

下面是堆栈跟踪…

at System.Net.Security.SslState.StartSendAuthResetSignal(ProtocolToken message, AsyncProtocolRequest asyncRequest, Exception exception)
at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ForceAuthentication(Boolean receiveFirst, Byte[] buffer, AsyncProtocolRequest asyncRequest)
at System.Net.Security.SslState.ProcessAuthentication(LazyAsyncResult lazyResult)
at System.Net.TlsStream.CallProcessAuthentication(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Net.TlsStream.ProcessAuthentication(LazyAsyncResult result)
at System.Net.TlsStream.Write(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.PooledStream.Write(Byte[] buffer, Int32 offset, Int32 size)
at System.Net.Mail.SmtpConnection.Flush()
at System.Net.Mail.SmtpConnection.GetConnection(String host, Int32 port)
at System.Net.Mail.SmtpTransport.GetConnection(String host, Int32 port)
at System.Net.Mail.SmtpClient.GetConnection()
at System.Net.Mail.SmtpClient.Send(MailMessage message)
at BulkEmail.frmemail.mailsending(String toaddress, String fromaddress, String fromname, String subject, String pwd, String attachements, String mailmessage, String htmlmessage, Int32 i, Int32 j, String replytoaddress)

当前回答

接受的答案中的代码帮助我调试问题。然后我意识到证书参数的SN字段与我认为的SMTP服务器不相同。通过将SmtpClient实例的Host属性设置为证书的SN值,我能够解决这个问题。

其他回答

我有完全相同的问题,并找出默认情况下,邮件屏蔽从Avast反病毒有“扫描SSL连接”激活。一定要把它关掉。

据我所知,Avast将“打开”邮件,扫描任何病毒,然后使用它自己的证书进行签名,这样邮件就不会被gmail的证书所签名,从而产生错误。

解决方案1:

关闭SSL扫描从你的防病毒(或整个邮件屏蔽)。

解决方案2(应该是最好的安全来说):

以某种方式获得反病毒使用的证书(Avast有一个选项可以导出它) 在连接到gmail服务器之前,将其导入imap/pop/smtp客户端。

警告:不要在产品代码中使用此代码!

作为一种解决方法,您可以关闭证书验证。只有在确认由于错误的证书而引发错误时才这样做。

在调用smtpclient.Send()之前调用这个方法:

[Obsolete("Do not use this in Production code!!!",true)]
static void NEVER_EAT_POISON_Disable_CertificateValidation()
{
    // Disabling certificate validation can expose you to a man-in-the-middle attack
    // which may allow your encrypted message to be read by an attacker
    // https://stackoverflow.com/a/14907718/740639
    ServicePointManager.ServerCertificateValidationCallback =
        delegate (
            object s,
            X509Certificate certificate,
            X509Chain chain,
            SslPolicyErrors sslPolicyErrors
        ) {
            return true;
        };
}

有一篇MSDN博客文章是关于调查这类问题的:

故障排除ASP。NET -根据验证过程,远程证书无效: http://blogs.msdn.com/b/jpsanders/archive/2009/09/16/troubleshooting-asp-net-the-remote-certificate-is-invalid-according-to-the-validation-procedure.aspx

在Amazon Linux EC2虚拟机上运行dotnet核心web应用程序时遇到此错误。原来我们已经有一段时间没有运行sudo yum update来修补这个服务器了,并且安装在机器上的根/中间证书已经过期了。(具体来说,本期从2021-09-30开始。)

我们运行这个命令来更新certs,然后重新启动dotnet进程:

Sudo yum更新ca-certificates

对于类似的问题,AWS支持人员进一步向我们指出了这篇支持文章:为什么我在EC2实例上收到Let's Encrypt证书的证书过期错误?

我知道我在这个游戏中已经很晚了,但我还没有看到指向系统的答案。TLS流的诊断日志。

在对代码进行任何更改之前,请确保您了解问题所在。AuthenticationException是一种非常通用的异常,它没有透露太多信息。要了解底层的工作原理,请编辑应用程序的app.config文件(或创建一个新文件),并确保拥有System。在系统中启用网络跟踪源。诊断部分,例如:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <system.diagnostics>
    <trace autoflush="true" />
    <sharedListeners>
      <add name="file" initializeData="c:\network.log" type="System.Diagnostics.TextWriterTraceListener" />
    </sharedListeners>
    <sources>
      <source name="System.Net" switchValue="Verbose">
        <listeners>
          <add name="file" />
        </listeners>
      </source>
    </sources>
  </system.diagnostics>
</configuration>

重新运行应用程序并检查c:\network.log文件。您应该会看到关于TLS (SSL)连接的详细信息,例如:

System.Net Information: 0 : [12764] InitializeSecurityContext(credential = System.Net.SafeFreeCredential_SECURITY, context = f44368:535f958, targetName = localhost, inFlags = ReplayDetect, SequenceDetect, Confidentiality, AllocateMemory, InitManualCredValidation)
System.Net Information: 0 : [12764] InitializeSecurityContext(In-Buffers count=2, Out-Buffer length=0, returned code=OK).
System.Net Information: 0 : [12764] Remote certificate: [Version]
  V3

[Subject]
  CN=test
  Simple Name: test
  DNS Name: example.com

[Issuer]
  CN=Root CA
  Simple Name: Root CA
  DNS Name: Root CA

...

[Signature Algorithm]
  sha256RSA(1.2.840.113549.1.1.11)

[Public Key]
  Algorithm: RSA
  Length: 2048
  Key Blob: ....
System.Net Information: 0 : [12764] SecureChannel#38496415 - Remote certificate has errors:
System.Net Information: 0 : [12764] SecureChannel#38496415 -    Certificate name mismatch.
System.Net Information: 0 : [12764] SecureChannel#38496415 - Remote certificate was verified as invalid by the user.
System.Net Error: 0 : [12764] Exception in AppDomain#10923418::UnhandledExceptionHandler - The remote certificate is invalid according to the validation procedure..

知道了问题的原因,您应该能够解决它,或者至少缩小您的谷歌搜索范围。