I have a certificate that I need to use in order to access a web service. The problem is that whenever I try to use the X509 certificate it asks for a passphrase (PIN). Is there any way of providing the passphrase directly, without it popping up the same window every time?
The certificate uses a dongle made by Oberthur Technologies, if it's of any help. Here's the code I use to get the certificate:
X509Store store = new X509Store("MY",StoreLocation.CurrentUser);
store.Open(OpenFlags.ReadOnly | OpenFlags.OpenExistingOnly);
X509Certificate2Collection collection = (X509Certificate2Collection)store.Certificates;
if(collection.Count != 0)
userCert = collection[0]; // everything's ok up to here
And here's where I use the certificate:
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(new Uri(url));
req.ClientCertificates.Add(userCert); // add the certificate I just got
// ...
WebResponse ret = req.GetResponse(); // here's where it asks me for my passphrase
The certificate's private key is stored on the Oberthur token. It is enforcing the user to enter the PIN to gain access to certificates private key. This is by design and cannot be overridden.
I am searching for a way to do it with managed code but haven't yet found one.
In the past I have just called the CAPI function CryptSetProvParam with option PP_SIGNATURE_PIN and the PIN as the data. This prevents the CSP from prompting the user for a PIN. It's kinda hard for a system service to enter that PIN :)
So, you will have to pinvoke CryptSetProvParam to do it.
Related
I programming in C# .Net Core 3.1 and .Net Standard library where this code is put.
I am not getting my http requests with RestSharp with a client certificate that are NOT installed on the server/computer i am not going to have access to the server/computer where this is going to be running later on..
My code:
// Create a RestSharp RestClient objhect with the base URL
var client = new RestClient(_baseAPIUrl);
// Create a request object with the path to the payment requests
var request = new RestRequest("swish-cpcapi/api/v1/paymentrequests");
// Create up a client certificate collection and import the certificate to it
X509Certificate2Collection clientCertificates = new X509Certificate2Collection();
clientCertificates.Import(_certDataBytes, _certificatePassword, X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.PersistKeySet);
// Add client certificate collection to the RestClient
client.ClientCertificates = clientCertificates;
//X509Certificate2 certificates = new X509Certificate2(_certDataBytes, _certificatePassword);
//client.ClientCertificates = new X509CertificateCollection() { certificates };
// Add payment request data
request.AddJsonBody(requestData);
var response = client.Post(request);
var content = response.Content;
I have done what ever i can find on internet and i have used the service test environment with there own generated certificate and generated my own in there production environment with the same result..
I have tested set TLS 1.1 or TLS 1.2 to test, they specified TLS 1.1 on there own curl examples.
Anyone got any idea?
Update 2020-01-08 - I have got information from the service tech support that they only see me sending one certificate but when i trying to debug and checking the X509Certificate2Collection i finding 3 certificate. But they saying they only see one?
IMHO, if the service you are trying to access is protected via SSL cert with expecting public key/private key, then without the cert, you cant access it. If thats the intent of the service to be protected, i think you may only do to check the service health check or at max, check if the service is accessible (without having the client cert)
But just as HTTPS, then you can try to download the cert from the browser if you can access the service URL from your browser, say, to access their meta or a simple GET or something. In chrome, you may see a lock symbol (security icon) just before to the URL. click that, and you may possibly download the public cert. You can install that on your machine and try that.
In case, if that service has a pub cert and the access doesnt need the client cert, then above option may work. and i hope you are installing the CERT and access that via your code from the account that has access to the cert. Lets say, you install the cert under the LocalSystem, then you may need administrator access from code/solution to access that cert path. Or install the cert under the current_user path.
I would Check if am able to access the service from browser as the first step.
This is, just from what i have understood from your question. again, if you can explain whether the service is a protected service based on public key/private key, you need to have the access/cert to use that service.
UPDATE:
I have tried few options on my end, by creating a demo api and a demo client to use client certs. With what i have understood from your query, i assume below may be some of your options to try out.
// --- using the cert path if you have the path (instead of the byte[])
var myCert = new X509Certificate2("<path to the client cert.cer/.pfx>", "secure-password", X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.PersistKeySet);
X509CertificateCollection clientCerts = new X509CertificateCollection();
clientCerts.Add(myCert);
OR
var certStore = new X509Store(StoreName.Root, StoreLocation.LocalMachine); //replace with appropriate values based on your cert configuration
certStore.Open(OpenFlags.ReadOnly);
//option 1 (ideally a client must have the cert thumbprint instead of a password
var cert = certStore.Certificates.Find(X509FindType.FindByThumbprint, "<cert Thumbprint>", false);
//option 2 (explore other options based on X509NameTypes
var cert = certStore.Certificates.OfType<X509Certificate2>()
.FirstOrDefault(cert => cert.GetNameInfo(X509NameType.DnsName, false) == "mycompany.dns.name.given in the cert");
client.ClientCertificates = new X509CertificateCollection(cert);
I recommend generate your own certificate
public static void MakeCert()
{
var ecdsa = ECDsa.Create(); // generate asymmetric key pair
var req = new CertificateRequest("cn=foobar", ecdsa, HashAlgorithmName.SHA256);
var cert = req.CreateSelfSigned(DateTimeOffset.Now, DateTimeOffset.Now.AddYears(10));
// Create PFX (PKCS #12) with private key
File.WriteAllBytes("c:\\temp\\mycert.pfx", cert.Export(X509ContentType.Pfx, "P#55w0rd"));
// Create Base 64 encoded CER (public key only)
File.WriteAllText("c:\\temp\\mycert.cer",
"-----BEGIN CERTIFICATE-----\r\n"
+ Convert.ToBase64String(cert.Export(X509ContentType.Cert), Base64FormattingOptions.InsertLineBreaks)
+ "\r\n-----END CERTIFICATE-----");
}
and then add to request
var client = new RestClient(url);
client.ClientCertificates = new X509CertificateCollection();
client.ClientCertificates.Add(new X509Certificate2("c:\\temp\\mycert.cer"));
I need to start using SNMPv3 over DTLS with certificates from the windows certificate store in c# and from what I've seen so far, this isn't used very often at all. Unfortunately, I have no choice in the matter.
I'm working on using DTLS.NET to do the handshake. One trick is that DTLS.NETseems to want a pem file instead of an X509 Certificate from the Windows Certificate Store. I believe I've figured out how to load the cert, except the private key. The private key is not exportable, and I don't believe I can change that.
public void LoadX509Certificate(X509Certificate2 certificate)
{
if (certificate == null)
{
throw new ArgumentNullException(nameof(certificate));
}
this._PrivateKey = DotNetUtilities.GetKeyPair(certificate.PrivateKey).Private;
this._Certificate = new Certificate
{
CertChain = new List<byte[]>() { certificate.RawData },
CertificateType = TCertificateType.X509
};
}
I believe I've figured out up to the certificate verify message and that's where it appears to need the private key.
CertificateVerify certificateVerify = new CertificateVerify();
byte[] signatureHash = _HandshakeInfo.GetHash();
certificateVerify.SignatureHashAlgorithm = new SignatureHashAlgorithm() { Signature = TSignatureAlgorithm.ECDSA, Hash = THashAlgorithm.SHA256 };
certificateVerify.Signature = TLSUtils.Sign(_PrivateKey, true, _Version, _HandshakeInfo, certificateVerify.SignatureHashAlgorithm, signatureHash);
SendHandshakeMessage(certificateVerify, false);
I can't seem to find much information in the RFCs or elsewhere that describe exactly what needs to happen here. I do know that the server can handle RSA, DSS, or ECDSA, so I left it with ECDSA since that's what DTLS.NET is using.
Do I actually need the private key to create the CertificateVerify message?
Thanks in advance!
The handshake may authenticate the client by it's certificate.
Though the certificate on it's own is "public", everyone would be able to send it and the authentication could not be granted.
Therefore the client has to proof, that he has access to the private key as well. That's why the "Certificate Verify" message is used.
If you don't have access to the private key of your public key of your certificate, a client certificate handshake is not possible.
Maybe the keystore doesn't export that private key, but offer instead a "signing" function, where that privte key is applied.
I have 2 approaches to do the same thing, but Azure has deprecated the one that works, and the other method doesn't work.
The approach that works, but is deprecated:
I store my PFX in Azure Key Vault Secrets. (when I create the secret I see a warning stating that this feature is deprecated)
and use the following code to retrieve it to create my certificate:
SecretBundle secret = await keyVaultClient.GetSecretAsync(keyVaultUrl, "MyCert-Secret");
X509Certificate2Collection exportedCertCollection = new X509Certificate2Collection();
exportedCertCollection.Import(Convert.FromBase64String(secret.Value));
X509Certificate2 certFromSecret = exportedCertCollection.Cast<X509Certificate2>().Single(s => s.HasPrivateKey);
credits to this answer
I'm able to use this certificate to host and access my application successfully.
The approach that doesn't work, but I should be using:
I store my certificate in the Azure Key vault Certificates
and use the following code to retrieve it and create the X509Certificate2:
CertificateBundle certificateBundle = await keyVaultClient.GetCertificateAsync(keyVaultUrl, "MyCert-Certificate");
X509Certificate2 certFromCertificate = new X509Certificate2(certificateBundle.Cer);
The problem with this approach is that the certificate does not contain the private key. i.e. certFromCertificate.HasPrivateKey is false.
My Questions
Why does certFromSecret have the PrivateKey, while certFromCertificate doesn't?
How can I retrieve a certificate from the key vault, where I can create a X509Certificate2 object to host my application in Kestrel with UseHttps.
The 2nd part of #Adrian's answer explains the concepts around the Azure KV Certificates very well, and I have changed my code as below to get the full certificate including the private keys:
SecretBundle secret = await kv.GetSecretAsync(keyVaultUrl, certName);
X509Certificate2 certificate =
new X509Certificate2(Convert.FromBase64String(secret.Value));
The trick was to use GetSecretAsync instead of GetCertificateAsync. Please refer to Adrian's SO answer to see why the secret had to be used to get the full certificate with Private keys.
Note that you should use "Certificate identifier" property (url with "/secrets/") from Azure certificate's property page.
The latest version of the SDK (Azure.Security.KeyVault.Certificates 4.2.0) now has the DownloadCertificateAsync method, which obtains the full cert (i.e. private key too) in a straightforward way.
The documentation states:
Because Cer contains only the public key, this method attempts to
download the managed secret that contains the full certificate.
X509Certificate2 cert = await certificateClient.DownloadCertificateAsync(certName);
I am able to successfully identify client certificates in a .NET thick client app, and the user is able to successfully select one.
X509Store store = new X509Store("MY", StoreLocation.CurrentUser);
store.Open(OpenFlags.OpenExistingOnly | OpenFlags.ReadOnly);
var fcollection = store.Certificates.Find(X509FindType.FindByApplicationPolicy, "1.3.6.1.5.5.7.3.2", true);
// other stuff where user selects one of them
Now how do I ask the user to answer the challenge (e.g. PIN in this case)?
I see there's a SignedXML.ComputeSignature() class, but it takes a byte stream, and I'm not sure where that comes from (perhaps in certificate.RawData[]?).
I'm not really as interested in getting the actual pin as I am that the card/pin match.
EDIT:
I tried using the private key from the smart card (and even encrypted from it), but I don't get asked for my PIN.
RSACryptoServiceProvider rsacsp = (RSACryptoServiceProvider)certificate.PrivateKey;
UnicodeEncoding ByteConverter = new UnicodeEncoding();
byte[] dataToEncrypt = ByteConverter.GetBytes("Data to Encrypt");
var encryptedData = RSAEncrypt(dataToEncrypt, rsacsp.ExportParameters(false), false);
Looks like the PIN request happens when I call RSACryptoServiceProvidersa.Decrypt.
Here's example code that worked perfectly for me in a Console app:
http://blog.aggregatedintelligence.com/2010/02/encryptingdecrypting-using.html
Much simpler in ASP.NET (aside from all the IIS config hassles/mysteries ...).
If this is a smartcard, the pin prompt will happen when you try to use the private key of the certificate.
You need to use the certificate somehow, and validate the result. For example, you might use the certificate to sign something. Once that signature operation happens, the pin prompt will appear.
If you don't really need to "use" the certificate, just want to validate that it's there and the user knows the pin, then you need some sort of proof of work. The certificate could be used to sign a challenge, and a remote server could validate the signature uses a key that belongs to a trusted root. Keep in mind this is difficult to get right, such as making sure you aren't open to a replay attack, etc.
I'm trying to authenticate myself against WebService using my client certificate, but, for some reasons (I explain), I don't want to load certificate from store, rather read it from disc.
The following:
// gw is teh WebService client
X509Certificate cert = new X509Certificate(PathToCertificate);
_gw.ClientCertificates.Add(ClientCertificate());
ServicePointManager.ServerCertificateValidationCallback = (a,b,c,d) => true;
_gw.DoSomeCall();
returns always 403 - the Service doesn't authorize me. But, when I save that certificate into CertStore, it works. (As stated in MSDN.)
Is it possible to use certificate not in store?
(the reason is, that I got windows service(client) sometimes calling webservice(server), and after unspecified amount of time the service 'forgets' my certificates and doesnt authorize against server, with no apparent reason)
What type of file is PathToCertificate? If it's just a .cer file, it will not contain the private key for the certificate and trying to use that certificate for SSL/TLS will fail.
However, if you have a PKCS7 or PKCS12 file that includes the public and private key for the certificate, your code will work (you might need to use the overload that takes a password if the private key has one).
To test this, I went to http://www.mono-project.com/UsingClientCertificatesWithXSP and created my client.p12 file following those instructions. I also created a simple HTTPS server using HttpListener for testing.
Then I compiled the following program into 'client.exe' and run like:
client.exe https://<MYSSLSERVER>/ client.p12 password
where client.p12 is the PKCS12 file generated before and 'password' is the password I set for the private key of the certificate.
using System;
using System.IO;
using System.Net;
using System.Security.Cryptography.X509Certificates;
using System.Text;
public class HttpWebRequestClientCertificateTest : ICertificatePolicy {
public bool CheckValidationResult (ServicePoint sp, X509Certificate certificate,
WebRequest request, int error)
{
return true; // server certificate's CA is not known to windows.
}
static void Main (string[] args)
{
string host = "https://localhost:1234/";
if (args.Length > 0)
host = args[0];
X509Certificate2 certificate = null;
if (args.Length > 1) {
string password = null;
if (args.Length > 2)
password = args [2];
certificate = new X509Certificate2 (args[1], password);
}
ServicePointManager.CertificatePolicy = new HttpWebRequestClientCertificateTest ();
HttpWebRequest req = (HttpWebRequest) WebRequest.Create (host);
if (certificate != null)
req.ClientCertificates.Add (certificate);
WebResponse resp = req.GetResponse ();
Stream stream = resp.GetResponseStream ();
StreamReader sr = new StreamReader (stream, Encoding.UTF8);
Console.WriteLine (sr.ReadToEnd ());
}
}
Let me know if you want me to upload the server code and the certificates used on both sides of the test.
The potential problem could be caching of SSL sessions (Schannel cache). Only first request negotiates the SSL handshake. Subsequent requests will use the same session ID and hope that the server accept it. If the server clears the SessionId, the requests will fail with 403 error. To disable local ssl session caching (and force SSL negotiation for each request) you have to open windows registry folder:
[HKEY_LOCAL_MACHINE][System][CurrentControlSet][Control][SecurityProviders][SCHANNEL]
and add the key named ClientCacheTime (DWORD) with value 0.
This issue is covered here:
http://support.microsoft.com/?id=247658
You have the potential for at least two problems...
First...
Your client certificate file cannot contain a private key unless it's accessed with a password. You should be using a PKCS #12 (*.pfx) certificate with a password so that your client has access to the private key. You client code will have to provide the password when opening the certificate as others have already posted. There are several ways to create this, the easiest is to use the following command-line to first generate the certificate, then use the MMC certificate manager to export the certificates private key:
Process p = Process.Start(
"makecert.exe",
String.Join(" ", new string[] {
"-r",// Create a self signed certificate
"-pe",// Mark generated private key as exportable
"-n", "CN=" + myHostName,// Certificate subject X500 name (eg: CN=Fred Dews)
"-b", "01/01/2000",// Start of the validity period; default to now.
"-e", "01/01/2036",// End of validity period; defaults to 2039
"-eku",// Comma separated enhanced key usage OIDs
"1.3.6.1.5.5.7.3.1," +// Server Authentication (1.3.6.1.5.5.7.3.1)
"1.3.6.1.5.5.7.3.2", // Client Authentication (1.3.6.1.5.5.7.3.2)
"-ss", "my",// Subject's certificate store name that stores the output certificate
"-sr", "LocalMachine",// Subject's certificate store location.
"-sky", "exchange",// Subject key type <signature|exchange|<integer>>.
"-sp",// Subject's CryptoAPI provider's name
"Microsoft RSA SChannel Cryptographic Provider",
"-sy", "12",// Subject's CryptoAPI provider's type
myHostName + ".cer"// [outputCertificateFile]
})
);
Second...
Your next problem is going to be server-side. The server has to allow this certificate. You have the right logic, but on the wrong side of the wire, move this line to the web server handling the request. If you cannot, you must then take the '.cer' file saved above to the server and add it to the server computer's trust list:
ServicePointManager.ServerCertificateValidationCallback = (a,b,c,d) => true;
Do you need a password for the certificate? If so, there is a field for it in the constructor.
X509Certificate cert = new X509Certificate(PathToCertificate,YourPassword);