C Ignore certificate errors

Question

I am getting the following error during a web service request to a remote web service      Could not establish trust relationship for the SSL TLS secure channel  ---  System Security Authentication AuthenticationException  The remote certificate is invalid according to the validation procedure     Is there anyway to ignore this error  and continue   It seems the remote certificate is not signed    The site I connect to is www czebox cz - so feel free to visit the site  and notice even browsers throw security exceptions

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This code worked for me  I had to add TLS2 because that s what the URL I am interested in was using   ServicePointManager SecurityProtocol   SecurityProtocolType Tls12  ServicePointManager ServerCertificateValidationCallback         sender  cert  chain  sslPolicyErrors    gt    return true     using  var client   new HttpClient          client BaseAddress   new Uri UserDataUrl       client DefaultRequestHeaders Accept Clear        client DefaultRequestHeaders Accept Add new       MediaTypeWithQualityHeaderValue  application json         Task lt string gt  response   client GetStringAsync UserDataUrl       response Wait         if  response Exception    null                 return null             return JsonConvert DeserializeObject lt UserData gt  response Result

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If you are using sockets directly and are authenticating as the client  then the Service Point Manager callback method won t work  Here s what did work for me  PLEASE USE FOR TESTING PURPOSES ONLY   var activeStream   new SslStream networkStream  false   a  b  c  d    gt    return true      await activeStream AuthenticateAsClientAsync  computer local      The key here  is to provide the remote certificate validation callback right in the constructor of the SSL stream

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Add a certificate validation handler  Returning true will allow ignoring the validation error   ServicePointManager      ServerCertificateValidationCallback          sender  cert  chain  sslPolicyErrors    gt  true

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Old  but still helps    Another great way of achieving the same behavior is through configuration file  web config    lt system net gt       lt settings gt         lt servicePointManager checkCertificateName  quot false quot  checkCertificateRevocationList  quot false quot    gt       lt  settings gt     lt  system net gt   NOTE  tested on  net full

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Allowing all certificates is very powerful but it could also be dangerous  If you would like to only allow valid certificates plus some certain certificates it could be done like this    Net core   using  var httpClientHandler   new HttpClientHandler          httpClientHandler ServerCertificateCustomValidationCallback    message  cert  chain  sslPolicyErrors    gt            if  sslPolicyErrors    SslPolicyErrors None                        return true      Is valid                    if  cert GetCertHashString       99E92D8447AEF30483B1D7527812C9B7B3A915A7                         return true                    return false             using  var httpClient   new HttpClient httpClientHandler                 var httpResponse   httpClient GetAsync  https   example com   Result             Net framework   System Net ServicePointManager ServerCertificateValidationCallback    delegate       object sender      X509Certificate cert      X509Chain chain      SslPolicyErrors sslPolicyErrors        if  sslPolicyErrors    SslPolicyErrors None                return true      Is valid            if  cert GetCertHashString       99E92D8447AEF30483B1D7527812C9B7B3A915A7                 return true             return false       Update   How to get cert GetCertHashString   value in Chrome   Click on Secure or Not Secure in the address bar       Then click on Certificate -  Details -  Thumbprint and copy the value  Remember to do cert GetCertHashString   ToLower

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The reason it s failing is not because it isn t signed but because the root certificate isn t trusted by your client  Rather than switch off SSL validation  an alternative approach would be to add the root CA cert to the list of CAs your app trusts   This is the root CA cert that your app currently doesn t trust   -----BEGIN CERTIFICATE----- MIIFnDCCBISgAwIBAgIBZDANBgkqhkiG9w0BAQsFADBbMQswCQYDVQQGEwJDWjEs MCoGA1UECgwjxIxlc2vDoSBwb8WhdGEsIHMucC4gW0nEjCA0NzExNDk4M10xHjAc BgNVBAMTFVBvc3RTaWdudW0gUm9vdCBRQ0EgMjAeFw0xMDAxMTkwODA0MzFaFw0y NTAxMTkwODA0MzFaMFsxCzAJBgNVBAYTAkNaMSwwKgYDVQQKDCPEjGVza8OhIHBv xaF0YSwgcy5wLiBbScSMIDQ3MTE0OTgzXTEeMBwGA1UEAxMVUG9zdFNpZ251bSBS b290IFFDQSAyMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAoFz8yBxf 2gf1uN0GGXknvGHwurpp4Lw3ZPWZB6nEBDGjSGIXK0Or6Xa3ZT tVDTeUUjT133G 7Vs51D6z ShWy 9T7a1f6XInakewyFj8PT0EdZ4tAybNYdEUO dShg2WvUyfZfXH 0jmmZm6qUDy0VfKQfiyWchQRi Ax6zXaU2 X3hXBfvRMr5l6zgxYVATEyxCfOLM9 a5U6lhpyCDf2Gg6dPc5Cy6QwYGGpYER1fzLGsN9stdutkwlP13DHU1Sp6W5ywtfL owYaV1bqOOdARbAoJ7q8LO6EBjyIVr03mFusPaMCOzcEn3zL5XafknM36Vqtdmqz iWR 3URAUgqE0wIDAQABo4ICaTCCAmUwgaUGA1UdHwSBnTCBmjAxoC gLYYraHR0 cDovL3d3dy5wb3N0c2lnbnVtLmN6L2NybC9wc3Jvb3RxY2EyLmNybDAyoDCgLoYs aHR0cDovL3d3dzIucG9zdHNpZ251bS5jei9jcmwvcHNyb290cWNhMi5jcmwwMaAv oC2GK2h0dHA6Ly9wb3N0c2lnbnVtLnR0Yy5jei9jcmwvcHNyb290cWNhMi5jcmww gfEGA1UdIASB6TCB5jCB4wYEVR0gADCB2jCB1wYIKwYBBQUHAgIwgcoagcdUZW50 byBrdmFsaWZpa292YW55IHN5c3RlbW92eSBjZXJ0aWZpa2F0IGJ5bCB2eWRhbiBw b2RsZSB6YWtvbmEgMjI3LzIwMDBTYi4gYSBuYXZhem55Y2ggcHJlZHBpc3UvVGhp cyBxdWFsaWZpZWQgc3lzdGVtIGNlcnRpZmljYXRlIHdhcyBpc3N1ZWQgYWNjb3Jk aW5nIHRvIExhdyBObyAyMjcvMjAwMENvbGwuIGFuZCByZWxhdGVkIHJlZ3VsYXRp b25zMBIGA1UdEwEB wQIMAYBAf8CAQEwDgYDVR0PAQH BAQDAgEGMB0GA1UdDgQW BBQVKYzFRWmruLPD6v5LuDHY3PDndjCBgwYDVR0jBHwweoAUFSmMxUVpq7izw r  S7gx2Nzw53ahX6RdMFsxCzAJBgNVBAYTAkNaMSwwKgYDVQQKDCPEjGVza8OhIHBv xaF0YSwgcy5wLiBbScSMIDQ3MTE0OTgzXTEeMBwGA1UEAxMVUG9zdFNpZ251bSBS b290IFFDQSAyggFkMA0GCSqGSIb3DQEBCwUAA4IBAQBeKtoLQKFqWJEgLNxPbQNN 5OTjbpOTEEkq2jFI0tUhtRx  6zwuqJCzfO KqggUrHBca GV qXcNzNAlytyM71 fMv VwgL9gBHTN IFIw100JbciI23yFQTdF UoEfK m IFfirxSRi8LRERdXHTEb vwxMXIzZVXloWvX64UwWtf4Tvw5bAoPj0O1Z2ly4aMTAT2a y z184UhuZ oGyMw eIakmFM7M7RrNki507jiSLTzuaFMCpyWOX7ULIhzY6xKdm5iQLjTvExn2JTvVChF Y jUu G0zAdLyeU4vaXdQm1A8AEiJPTd0Z9LAxL6Sq2iraLNN36 NyEK ts3mPLL  -----END CERTIFICATE-----   You can decode and view this certificate using   this certificate decoder or another certificate decoder

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To further expand on BIGNUM s post - Ideally you want a solution that will simulate the conditions you will see in production and modifying your code won t do that and could be dangerous if you forget to take the code out before you deploy it   You will need a self-signed certificate of some sort  If you know what you re doing you can use the binary BIGNUM posted  but if not you can go hunting for the certificate  If you re using IIS Express you will have one of these already  you ll just have to find it  Open Firefox or whatever browser you like and go to your dev website  You should be able to view the certificate information from the URL bar and depending on your browser you should be able to export the certificate to a file   Next  open MMC exe  and add the Certificate snap-in  Import your certificate file into the Trusted Root Certificate Authorities store and that s all you should need  It s important to make sure it goes into that store and not some other store like  Personal   If you re unfamiliar with MMC or certificates  there are numerous websites with information how to do this   Now  your computer as a whole will implicitly trust any certificates that it has generated itself and you won t need to add code to handle this specially  When you move to production it will continue to work provided you have a proper valid certificate installed there  Don t do this on a production server - that would be bad and it won t work for any other clients other than those on the server itself

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This works for  Net Core  Call on your Soap client   client ClientCredentials ServiceCertificate SslCertificateAuthentication                   new X509ServiceCertificateAuthentication                                         CertificateValidationMode   X509CertificateValidationMode None                      RevocationMode   X509RevocationMode NoCheck

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IgnoreBadCertificates Method     I use a method to ignore bad certs caused by misc errors IgnoreBadCertificates        after the Ignore call i can do what ever i want    HttpWebRequest request data   System Net WebRequest Create urlquerystring  as HttpWebRequest      and below the Methods we are using             lt summary gt      Together with the AcceptAllCertifications method right     below this causes to bypass errors caused by SLL-Errors       lt  summary gt  public static void IgnoreBadCertificates         System Net ServicePointManager ServerCertificateValidationCallback   new System Net Security RemoteCertificateValidationCallback AcceptAllCertifications             lt summary gt      In Short  the Method solves the Problem of broken Certificates      Sometime when requesting Data and the sending Webserverconnection     is based on a SSL Connection  an Error is caused by Servers whoes     Certificate s  have Errors  Like when the Cert is out of date     and much more    So at this point when calling the method      this behaviour is prevented      lt  summary gt       lt param name  sender  gt  lt  param gt       lt param name  certification  gt  lt  param gt       lt param name  chain  gt  lt  param gt       lt param name  sslPolicyErrors  gt  lt  param gt       lt returns gt true lt  returns gt  private static bool AcceptAllCertifications object sender  System Security Cryptography X509Certificates X509Certificate certification  System Security Cryptography X509Certificates X509Chain chain  System Net Security SslPolicyErrors sslPolicyErrors        return true

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Bypass SSL Certificate              HttpClientHandler clientHandler   new HttpClientHandler            clientHandler ServerCertificateCustomValidationCallback    sender  cert  chain  sslPolicyErrors    gt    return true                 Pass the handler to httpclient from you are calling api          var client   new HttpClient clientHandler

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To disable ssl cert validation in client configuration    lt behaviors gt      lt endpointBehaviors gt         lt behavior name  DisableSSLCertificateValidation  gt            lt clientCredentials gt                lt serviceCertificate gt                   lt sslCertificateAuthentication certificateValidationMode  None    gt                 lt  serviceCertificate gt              lt  clientCredentials gt           lt  behavior gt

[c#] C# Ignore certificate errors?

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