Develop Reference

Delete any cert of certmgr without FriendlyName or <None>

I I'm having trouble making a filter that deletes any cert that doesn't have firendlyname from my certificate store in general.
Im using c# console.
I tried that but it doesn't seem to be doing anything. Still not doing anything about what I want, does anyone have a solution, thank you.
private static void RemoveUnwantedCert()
{
// Open the Root store
string RootStoreName = "Root";
StoreLocation RootStoreLocation = StoreLocation.LocalMachine;
X509Store RootStore = new X509Store(RootStoreName, RootStoreLocation);
RootStore.Open(OpenFlags.ReadOnly);
// Get all certificates in the Root store
X509Certificate2Collection certificates = RootStore.Certificates;
// Loop through all the certificates in the Root store
foreach (X509Certificate2 certificate in certificates)
{
if (certificate.FriendlyName == "None")
try
{
// Open the Root store again, this time with ReadWrite permissions
RootStore.Open(OpenFlags.ReadWrite);
// Remove the certificate from the Root store
RootStore.Remove(certificate);
// Close the Root store
RootStore.Close();
}
catch (Exception) { }
// Break out of the loop
break;
}
// Close the Root store
RootStore.Close();
```
`
I tried that but it doesn't seem to be doing anything. Still not doing anything about what I want, does anyone have a solution, thank you.

To remove a certificate and all certificates in the chain -
X509Certificate2Collection col = store.Certificates.Find(X509FindType.FindBySubjectName, "yoursubjectname", false);
var chain = new X509Chain();
chain.Build(col[0]);
var allCertsInChain = new X509Certificate2Collection();
foreach (var entry in chain.ChainElements)
{
allCertsInChain.Add(entry.Certificate);
}
store.RemoveRange(allCertsInChain);

Thanks but i just want delete a specified one.

C# sign data ECDSA from smartcard

I am trying to sign some data using the private key from the smart card. The key algorithm is ECDSA. when I try to get the private key object it occurs system not supported exception.
Then after some research, I get to know that X509Certificate2 is not supporting EC Keys.
sysSec.X509Certificate2 cert = CertHelper.GetSignCertificate(serialNumber); //Get Certificate from Store var
key = cert.PrivateKey;
Then i try to use Bouncy Castle library. But in here i couldn't get ECPrivateKeyParameters after parsing X509Certificate2 . There is a code :
byte[] pkcs12Bytes = cert.Export(sysSec.X509ContentType.Pkcs12,"test");
Pkcs12Store pkcs12 = new Pkcs12StoreBuilder().Build();
pkcs12.Load(new MemoryStream(pkcs12Bytes, false), "test".ToCharArray());
ECPrivateKeyParameters privKey = null;
foreach (string alias in pkcs12.Aliases)
{
if (pkcs12.IsKeyEntry(alias))
{
privKey = (ECPrivateKeyParameters)pkcs12.GetKey(alias).Key;
break;
}
}
It also not works. But strange things happen when I create CMS file. It works.
public byte[] Sign(byte[] data , X509Certificate2 certificate ,bool detached )
{
if (data == null)
throw new ArgumentNullException("data");
if (certificate == null)
throw new ArgumentNullException("certificate");
// setup the data to sign
// ContentInfo content = new ContentInfo( new Oid("1.3.14.3.2.26"), data);
ContentInfo content = new ContentInfo( data);
SignedCms signedCms = new SignedCms(content, detached);
CmsSigner signer = new CmsSigner(SubjectIdentifierType.IssuerAndSerialNumber, certificate);
signer.SignedAttributes.Add(new Pkcs9DocumentName("testname"));
signer.SignedAttributes.Add(new Pkcs9SigningTime());
//signer.;
// CmsRecipientCollection recipest =new CmsRecipientCollection ()
// create the signature
signedCms.ComputeSignature(signer);
// signedCms.ComputeSignature()
byte[] res = signedCms.Encode();
foreach (SignerInfo info in signedCms.SignerInfos)
{
foreach (var item in info.SignedAttributes)
{
string frname = item.Oid.FriendlyName ?? "null";
Console.WriteLine(string.Format(" OID {0} : Value {1}", frname, item.Oid.Value.ToString()));
}
foreach (var item in info.UnsignedAttributes)
{
string frname = item.Oid.FriendlyName ?? "null";
Console.WriteLine(string.Format(" OID {0} : Value {1}", frname, item.Oid.Value.ToString()));
}
}
Console.WriteLine("Signed !");
return res;
}
So do anyone knows how to handle it?
Also how to sign from smartCard using Bouncy Castle?

According to my understanding BouncyCastle is a cryptographic library. It can sign something, if you provide the key. Smart cards however don't typically export private keys (so I have some doubts, whether your certificate contains the one from the smart card) but expect commands to sign something, e. g. by receiving the respective hash value and returning the signature (after ensuring appropriate user authentication).
This is typically accomplished using a PKCS#11 interface (assumed you have a driver for it matching the command set of your card) or by sending the appropriate command APDUs directly to the card (quite complicated) from your application. I found nothing on the bouncy castle website, suggesting that there is some support for addressing smart cards. (It may be hidden in the OpenPGP functionality, if your card is compliant to that standard.)
So without being acquainted with BouncyCastle it seems to me, that it won't match your expectations.

C# list installed certificates

first i'm an complete newby on c#, so im just searching on the web for posibilities
What i want to get: I want a button which retrieves a list of installed certificates in the personal store.
i tried already a little, but get messages about missing references etc. So i hope someone can give me a litte advice how to achieve this.
what i found on the web is:
using System.Security.Cryptography.X509Certificates;
public static X509Certificate2 selectCert(StoreName store, StoreLocation location, string windowTitle, string windowMsg)
{
X509Certificate2 certSelected = null;
X509Store x509Store = new X509Store(store, location);
x509Store.Open(OpenFlags.ReadOnly);
X509Certificate2Collection col = x509Store.Certificates;
X509Certificate2Collection sel = X509Certificate2UI.SelectFromCollection(col, windowTitle, windowMsg, X509SelectionFlag.SingleSelection);
if (sel.Count > 0)
{
X509Certificate2Enumerator en = sel.GetEnumerator();
en.MoveNext();
certSelected = en.Current;
}
x509Store.Close();
return certSelected;
}
yours
(i use visual studio...)

Add a reference to System.Security.dll to use the X509Certificate2UI class.
you can use foreach
if (sel.Count > 0){
foreach(var cert in sel){
certSelected = cert ;
}
}
you can make it even shorte when using linq
using System.Linq;
...
if (sel.Count > 0){
return sel.FirstOrDefault();
}

Service account cannot load the X509Certificate from windows certificate store

All, I run into an issue where the service account my ASP.NET web forms application (.Net Framework 4.6.1) runs under cannot load the X509Certificate(.pfx) from the personal store on the windows 2012 R2 server .Here is how I imported the certificate to the certificate store
I Logged into the server using the service account(domain\username) ,used mmc snap in to import the certificate to Current User Personal Certificate Store (please see screenshot at the end)
This is the code I am using to load the certificate in C#.But the certificate
is null
public X509Certificate2 Load()
{
X509Certificate2 x509Certificate = null;
var store = new X509Store(StoreName.My,StoreLocation.CurrentUser);
string thumbPrint = StripTheSpacesAndMakeItUpper(ConfigurationManager.AppSettings["pfxthumbPrint"]);
store.Open(OpenFlags.ReadOnly);
var certCollection = store.Certificates;
foreach (var x509 in certCollection)
{
if (x509.Thumbprint.Equals(thumbPrint))
{
x509Certificate = x509;
break;
}
}
store.Close();
return x509Certificate;
}
private string StripTheSpacesAndMakeItUpper(string thumbPrint)
{
if(!string.IsNullOrWhiteSpace(thumbPrint))
{
return Regex.Replace(thumbPrint, #"\s|\W", "").ToUpper();
}
return thumbPrint;
}
Any suggestions on why the method Load returns null ?
]3

I don't know how you set the value of ConfigurationManager.AppSettings["pfxthumbPrint"]. I guess you double clicked the certificate in your CurrentUser store and copied the thumbprint from the Details tab, right? If that is the case, you copied also one invisible character from the beginning of the thumbprint.
The saddest thing is that this character (I don't know what it is) is not visible in your app.config/web.config. The only way to get rid of if is to delete the first quote character with the first character of the thumbprint and type them in again manually. Or delete entire thumbprint and the quotes and type them again if you wish.

Instead of
if (x509.Thumbprint.Equals(x509CertificateFriendlyName))
Shouldn't it be
if (x509.Thumbprint.Equals(thumbPrint))
...?
Also, you appear to have x509Certificate declared as a local variable and then you discard it. Did you intend to assign the value to an instance variable perhaps? I don't even see a return statement.
Also, you're not disposing your store, although that probably isn't the cause of your issue.
Here's a different version that addresses these issues, and will also eliminate any invisible characters in the configuration entry (see pepo's answer for why).
public X509Certificate2 Load()
{
var thumbPrintFromConfig = ConfigurationManager.AppSettings["pfxthumbPrint"]
var thumbPrint = Regex.Replace(thumbPrintFromConfig.ToUpper(),"[^A-F0-9]",""); //Keep only hex digits
return Load(thumbPrint);
}
private X509Certificate2 Load(string thumbPrint)
{
using (var store = new X509Store(StoreName.My,StoreLocation.CurrentUser))
{
store.Open(OpenFlags.ReadOnly);
var cert = store
.Certificates
.OfType<X509Certificate2>()
.Where(x => x.Thumbprint == thumbPrint)
.Single();
store.Close();
return cert;
}
}

Add a generated certificate to the store and update an IIS site binding

I'm running into the following and after feeling like I've exhausted various avenues of research on Google and Stack Overflow I decided to just ask my own question about it.
I'm trying to generate a personal certificate (using BouncyCastle) based on a CA certificate that I already have and own. After generating the certificate, placing it in the 'My' store, I then attempt to update my IIS website's SSL binding to use this new certificate.
What I'm noticing is that the updates to the IIS website (using ServerManager) are not throwing exception, yet when I go to the IIS Manager console I notice the website's binding has no SSL certificate selected. When I attempt to select the certificate that I created (shows up fine as a viable option) I get the following error message:
A specified logon session does not exist. It may already have been terminated. (Exception from HRESULT: 0x80070520)
As a test I exported my generated certificate (with the private key) and reinstalled it via the wizard and then once again tried setting up the binding (via IIS Manager) which worked.
Because of this behavior I assumed it was an issue with how I was generating or adding the certificate to the store. I was hoping someone may have some idea of what the issue I'm having may be. The following are the relevant functions (I believe) used in creating the certificate, adding it to the store, and updating the website's binding programmatically:
Main function the generates that get the CA certificate private key, generates the personal self-signed certificate, and updates the sites binding:
public static bool GenerateServerCertificate(
X509Certificate2 CACert,
bool addToStore,
DateTime validUntil)
{
try
{
if (CACert.PrivateKey == null)
{
throw new CryptoException("Authority certificate has no private key");
}
var key = DotNetUtilities.GetKeyPair(CACert.PrivateKey).Private;
byte[] certHash = GenerateCertificateBasedOnCAPrivateKey(
addToStore,
key,
validUntil);
using (ServerManager manager = new ServerManager())
{
Site site = manager.Sites.Where(q => q.Name == "My Site").FirstOrDefault();
if (site == null)
{
return false;
}
foreach (Binding binding in site.Bindings)
{
if (binding.Protocol == "https")
{
binding.CertificateHash = certHash;
binding.CertificateStoreName = "MY";
}
}
manager.CommitChanges();
}
}
catch(Exception ex)
{
LOG.Error("Error generating certitifcate", ex);
return false;
}
return true;
}
Generating the certificate based on the CA private key:
public static byte[] GenerateCertificateBasedOnCAPrivateKey(
bool addToStore,
AsymmetricKeyParameter issuerPrivKey,
DateTime validUntil,
int keyStrength = 2048)
{
string subjectName = $"CN={CertSubjectName}";
// Generating Random Numbers
CryptoApiRandomGenerator randomGenerator = new CryptoApiRandomGenerator();
SecureRandom random = new SecureRandom(randomGenerator);
ISignatureFactory signatureFactory = new Asn1SignatureFactory("SHA512WITHRSA", issuerPrivKey, random);
// The Certificate Generator
X509V3CertificateGenerator certificateGenerator = new X509V3CertificateGenerator();
certificateGenerator.AddExtension(
X509Extensions.ExtendedKeyUsage,
true,
new ExtendedKeyUsage((new List<DerObjectIdentifier> { new DerObjectIdentifier("1.3.6.1.5.5.7.3.1") })));
// Serial Number
BigInteger serialNumber = BigIntegers.CreateRandomInRange(BigInteger.One, BigInteger.ValueOf(Int64.MaxValue), random);
certificateGenerator.SetSerialNumber(serialNumber);
// Issuer and Subject Name
X509Name subjectDN = new X509Name(subjectName);
X509Name issuerDN = new X509Name(CACertificateName);
certificateGenerator.SetIssuerDN(issuerDN);
certificateGenerator.SetSubjectDN(subjectDN);
// Valid For
DateTime notBefore = DateTime.UtcNow.Date;
DateTime notAfter = validUntil > notBefore ? validUntil : notBefore.AddYears(1);
certificateGenerator.SetNotBefore(notBefore);
certificateGenerator.SetNotAfter(notAfter);
// Subject Public Key
AsymmetricCipherKeyPair subjectKeyPair;
var keyGenerationParameters = new KeyGenerationParameters(random, keyStrength);
var keyPairGenerator = new RsaKeyPairGenerator();
keyPairGenerator.Init(keyGenerationParameters);
subjectKeyPair = keyPairGenerator.GenerateKeyPair();
certificateGenerator.SetPublicKey(subjectKeyPair.Public);
// Generating the Certificate
Org.BouncyCastle.X509.X509Certificate certificate = certificateGenerator.Generate(signatureFactory);
// correcponding private key
PrivateKeyInfo info = PrivateKeyInfoFactory.CreatePrivateKeyInfo(subjectKeyPair.Private);
// merge into X509Certificate2
X509Certificate2 x509 = new X509Certificate2(certificate.GetEncoded());
Asn1Sequence seq = (Asn1Sequence)Asn1Object.FromByteArray(info.ParsePrivateKey().GetDerEncoded());
if (seq.Count != 9)
{
throw new PemException("Malformed sequence in RSA private key");
}
RsaPrivateKeyStructure rsa = RsaPrivateKeyStructure.GetInstance(seq);
RsaPrivateCrtKeyParameters rsaparams = new RsaPrivateCrtKeyParameters(
rsa.Modulus,
rsa.PublicExponent,
rsa.PrivateExponent,
rsa.Prime1,
rsa.Prime2,
rsa.Exponent1,
rsa.Exponent2,
rsa.Coefficient);
x509.PrivateKey = DotNetUtilities.ToRSA(rsaparams);
if (addToStore)
{
// Add certificate to the Personal store
AddCertToStore(x509, StoreName.My, StoreLocation.LocalMachine, "Certificate Friendly Name");
}
return x509.GetCertHash();
}
Adding the certificate to the store:
private static void AddCertToStore(X509Certificate2 cert, StoreName storeName, StoreLocation storeLocation, string friendlyName)
{
X509Store store = new X509Store(storeName, storeLocation);
try
{
store.Open(OpenFlags.ReadWrite);
store.Add(cert);
if (!string.IsNullOrWhiteSpace(friendlyName)) {
var certs = store.Certificates.Find(X509FindType.FindBySubjectDistinguishedName, cert.Subject, true);
if (certs.Count > 0)
{
certs[0].FriendlyName = friendlyName;
}
}
}
finally
{
store.Close();
}
}
Just a final note, I have tried a few things from what I've seen on various sites in regards to that error (doesn't seem very clear what the issue is):
This works on a different box (my personal development machine) but I hit these snags on a server machine (running Windows Server 2012 R2)
The IIS Help dialog informs me the machine is running IIS 8.5
Verified the validity generated certificate and the CA certificate with CertUtil.exe
Verified the generated certificate and the CA certificate had a private key that could be found
Verified administrators (and eventually even my logged in account) had access to where the private key file for both the CA certificate and the generated certificate.
Any ideas what my issue could be?
Update:
I was able to get some results by doing the following:
Export my certificate to a file programmatically by doing File.WriteAllBytes(filePath, cert.Export(X509ContentType.Pkcs12, password));
Then I import this certificate file to the store by doing:
var cert = new X509Certificate2(certFilePath, certPassword, X509KeyStorageFlags.Exportable | X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.PersistKeySet);
// My original AddCertToStore function
AddCertToStore(cert, StoreName.My, StoreLocation.LocalMachine, "Friendly Name");
Finally, I set the binding as I was doing earlier:
using (ServerManager manager = new ServerManager())
{
Site site = manager.Sites.Where(q => q.Name == "My Site").FirstOrDefault();
if (site == null)
{
return false;
}
foreach (Binding binding in site.Bindings)
{
if (binding.Protocol == "https")
{
binding.CertificateHash = certHash;
binding.CertificateStoreName = "MY";
}
}
manager.CommitChanges();
}
Doing it this way works, but I don't see why I would have export the certificate to a file, THEN load it into a X509Certificate2 object, add to the store, and finally set up the binding.

The ToRSA method most likely creates an ephemeral RSA key, so when the references are all gone the key gets deleted. Exporting the ephemeral structure into a PFX then re-importing it with PersistKeySet is one way to turn it into a persisted key. Others exist, but that one is one of the less convoluted ones.
You don't actually have to write it to a file, though.
byte[] pkcs12Blob = cert.Export(X509ContentType.Pkcs12, password);
ver certWithPersistedKey = new X509Certificate2(pkcs12Blob, password, allTheFlagsYouAlreadySet);
There are also other subtleties going on, like setting the PrivateKey property has different behaviors for a cert instance that was loaded from a store and one which was loaded from bytes... the PFX/PKCS#12 export/import works around all of those.

For us, it was related to an invalid certificate. We went to IIS >> Server Certificates and exported the certificate from there.
The certificate was correctly bound to IIS site after that.