CERTENROLLLib alternatives in .Net Core

Question

I would like to decode Certificate Requests PCKS #10 to obtain all necessary information such Common Name, Key Length and most important Subject Alternate Names.

Previously on .Net WebFroms I used CERTENROLLLib library and CX509ExtensionAlternativeNames/CX509CertificateRequestPkcs10 classes. Now I'm looking for replacement in .Net Core

Answer 1

Neither .NET Core nor .NET Framework has built-in support for reading PKCS#10 blobs / certificate signing requests. You'll need to use a 3rd party library (Portable.BouncyCastle might work, and might have what you need), or read RFC 2986 and parse the data yourself.

If you don't know how to read DER encoded data, ITU X.680 will explain the ASN.1 syntax:

CertificationRequestInfo ::= SEQUENCE {
    version       INTEGER { v1(0) } (v1,...),
    subject       Name,
    subjectPKInfo SubjectPublicKeyInfo{{ PKInfoAlgorithms }},
    attributes    [0] Attributes{{ CRIAttributes }}
}

And ITU X.690 will explain how the structures from ASN.1 are encoded under the Distinguished Encoding Rules (DER).