How to decode a CSR File?

I ran accross a CSR file (Certificate Signing Request) and I need to extract some information from it.

There's a way to decode it using .NET Framework?

4 Answers

It's not .NET, but for interactive use, try the OpenSSL utilities. Specifically:

openssl req -text -in request.csr

certutil -dump file.csr

Will also dump all relevant information. Builtin in Windows by default.

Decoding a CSR is easy if you employ the OpenSSL.NET library:

// Load the CSR file
var csr = new X509Request(BIO.File("C:/temp/test.csr", "r"));
OR
var csr = new X509Request(@"-----BEGIN CERTIFICATE REQUEST-----...");
// Read CSR file properties
Console.WriteLine(csr.PublicKey.GetRSA().PublicKeyAsPEM);
Console.WriteLine(csr.Subject.SerialNumber);
Console.WriteLine(csr.Subject.Organization);
.
.
.

X509Request type has properties to get everything out of your CSR file text.

Try Liping Dai's website. His LCLib has ASN1 Parser which wrote in C#. It can decode CSR. Work for me.