Does root CA certificate in a certificate chain will also checked for revocation status using CRL downloaded from the root CA CDP?
It depends on certificate chaining engine implementation. For example, Microsoft CryptoAPI defaults to no revocation checking. Options are:
Leaf certificate only
Entrie chain, including root
Entire chain excluding root
.NET wrapper X509Chain defaults to entire chain excluding root. Applications are responsible to configure revocation checking options when calling chaining engine. Non-Microsoft platforms and tools (OpenSSL, for example) are configurable as well and exact default behavior depends on an implementation and client configuration.
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I am currently working with SSLSockets and I want to create an application that will be released to the public - for example an android app, iOS app or similar.
I have a domain which is secured by an SSL-certificate. Is it safe to generate a keystore from that certificate and insert it into the project-jar and pass it to the user? Is the keystore still valid when the ssl-certificate has to be updated?
You already got the point, if you create a trust store with the leaf certificate (the certificate used by the server) in it you have to update it every time the certificate is updated on the server (depending on the used CA every 3-12 months).
Therefore the common solution is to include the intermediate or root CA certificate as those certificates typically have validity time of up to 10 years or more. If you include intermediate or root CA certificate you don't have to update the app if just the server certificate is renewed by the same CA.
We are using IdentityServer4 and our version loads the signing key from a PFX file in file system or from the windows certificate store. Using the certificate works. The question is - which certificate issuer should be used in production?
Is a certificate from a public CA recommended? Or is it enough to have a self-signed certificate (without a CA at all) such as it can be created with IIS Manager?
In our tests we have found that the client could still validate the signature in the access token, even if the signing certificate would not have a valid CA chain on the client.
In the docs, it says that you can also use raw key material instead of a certificate:
http://docs.identityserver.io/en/latest/topics/crypto.html#token-signing-and-validation
In this scenario there would be no CA chain whatsoever.
That leads me to the assumption, that when the client loads the public signing key (via the HTTP(s) endpoint), the CA chain information might not be passed anyways. Is that right? Through the loading mechanism via HTTPs you also have a combined security mechanism.
So my conclusion is that for the signing credential a self-signed cert is just as safe as one from VeriSign. Can this be confirmed?
There is no certificate involved in signing and verifying the tokens. Only a private and public key (RSA or ECDSA key).
However a certificate can be useful to "import/transport" the keys into .NET. So, because of that we don't care about who issued the certificate.
When importing the key, one approach is to bundle the certificate that holds the public key + the private key and store it in a PKCE#12 file (.pfx/.p12 extension). Then load that file into .NET. Before .NET 5 working with keys was a bit hard.
The more important thing is that you can manage and deploy the private key in a secure way and that it is persisted over time.
Optionally, you can add support for key-rotation.
I am developing a desktop application. I can code sign it with .pfx file. I will get that from CA. But what if I want to install it in a different system. Will it reflect there as well? Because I can't share my .pfx file with everyone.
You should not share the *pfx as it contains the private key.
The trust to the signature comes from the trust chain - so when the issuing CA and all intermediate CAs up to the root CA are in the trust store (Windows Trust Store, MAC Key Chain or cacerts.pem for OpenSSL/Java) the signature is trusted as long as
the certificate is not revoked
the signature certificate is not expired or the signature contains a counter signature (RFC3161 timestamp).
We have a root certificate authority made with OpenSSL. Its file-based, runs on RHEL, uses "serial" and "index.txt" etc.
Now in a lab environment we have added an intermediate standalone certificate authority using Active Directory Certificate Services, standalone (i.e. not an AD or domain member), running on Windows Server 2012 (all latest updates applied). We signed the intermediate CA with our root and ADCS is up and running successfully. But what we're finding is that we actually cannot issue any certs from this intermediate CA.
When we use the management console and attempt to issue a requested cert, the cert ends up in "Failed Requests" with the message:
Active Directory Certificate Services denied request 4 because The revocation function was unable to check revocation for the certificate. 0x80092012 (-2146885614 CRYPT_E_NO_REVOCATION_CHECK).
The request was for CN=obelisk.sand.idfconnect.lan, OU=IDFC, O="IDF Connect, Inc.", L=Wilmington, S=Delaware, C=US. Additional information: Error Constructing or Publishing Certificate Resubmitted by OBELISK\Administrator
If I look at the request, I can see the is defined as:
[1]CRL Distribution Point
Distribution Point Name:
Full Name:
URL=file:////obelisk.sand.idfconnect.lan/CertEnroll/Obelisk Intermediate CA.crl (file:////obelisk.sand.idfconnect.lan/CertEnroll/Obelisk%20Intermediate%20CA.crl)
If I use IE to browse that file:// url, it pops open Windows Explorer, where I see the files I'd expect, i.e.
nsrev_Obelisk Intermediate CA.asp
Obelisk Intermediate CA.crl
Obelisk Intermediate CA+.crl
obelisk.sand.idfconnect.lan_Obelisk Intermediate CA.crt
Lastly, when I view the properties of the intermediate CA from the MMC, and look at its certificate, at the bottom of the details it says: "Extended Error Information: Revocation Status : The revocation function was unable to check revocation for the certificate."
Any advice to get this intermediate CA working greatly appreciated!
Add the public root certificate to the machine store (certlm.msc) trusted root certificate authorities.
Add the public root certificate CRL to the machine store (certlm.msc) trusted root certificate authorities.
I'm using the SignedXml.CheckSignature(X509Certificate2, boolean) method. I would like to know what checks are performed when deciding the validity of the certificate. I have verified that the Current User/Not Trusted list is checked. The documentation says it will use the "address book" store, searching by subject key identifier, to build the certificate chain. I imagine this means the Local Machine and Current User certificate stores?
Am I right to think that certificate revocation and signature timestamp are not checked? To do an OCSP check for certificate revocation, am I obliged to use Bouncy Castle?
In the remarks in the msdn article you link to one finds:
In version 1.1 of the .NET Framework, the X.509 certificate is not verified.
In version 2.0 and later, the X.509 certificate is verified.
In version 2.0 and later of the .NET Framework, the CheckSignature method will search the "AddressBook" store for certificates suitable for the verification. For example, if the certificate is referenced by a Subject Key Identifier (SKI), the CheckSignature method will select certificates with this SKI and try them one after another until it can verify the certificate.
Thus, first of all the behavior of that method has changed in different .NET framework versions. So for reproducible results, you had better not count on that method even check the certificate at all.
Furthermore, the formulation try them one after another until it can verify the certificate sounds like there just might be the mathematical test whether or not the certificate is signed by its alleged issuer.
https://referencesource.microsoft.com/#System.Security/system/security/cryptography/xml/signedxml.cs,b9518cc2212419a2
It checks
The certificate has no Key Usage extension, or the Key Usage extension has either Digital Signature or Non Repudiation usages enabled
The certificate chains up to a trusted root authority
The certificate has not been revoked
The certificate was not expired when you called this method
It doesn't know when the document was signed, so it doesn't answer that question.
That none of the certificates in the chain are explicitly prohibited by the user or system configuration.