It seems you are asking how to get a tool that will generate the .c and .h files for you from the ASN.1 specification. There is an excellent list of ASN.1 compilers (both free and commercial) in the ITU-T ASN.1 Project at https://www.itu.int/en/ITU-T/asn1/Pages/Tools.aspx which you can use to read the ASN.1 specification and generate code to encode/decode/validate the messages in your ASN.1 specification. If this is not what you are asking, please clarify your question.