Implementation Of DER Coding/Decodign For Certificate & Key Management System

As the key technology to guarantee the security of Internet applications and e-business, the certificate and key management system has been and will be used extensively in the Internet applications. In the certificate and key management system, coding/decoding is a fundamenta! module, which is used to provide an interface betvveen transmitter and receiver for certificates and messages. It plays an important role in the whole system.Based on a practical certificate and key management system, this paper describes its' encoding and decoding method of DER in great details. The related implementation process is also discussed and an application-oriented coding/decoding tool is realized.Firstly, ASN.l (Abstract Syntax Notation 1) is discussed and it's encoding rules (BER,DER,CER and PER) are compared. As a result, DER is used for the system proposed in this thesis. Secondly, the coding/decoding library is presented and realized. This library consists of coding/decoding functions which can be used directly by applications. Because the original library is designed specially for the specific key management applications, it is therefore not easy to be extended. So a new coding/decoding plan is also put fonvard and it has overcome the disadvantage of the original library. That is to say the new coding/decoding library is independent of given applications and can be extended easily. Finally, programming for the new coding/decoding library is also done step by step. The first step is to finish the common coding module. Based on this module, the coding/decoding of ASN. l basic type and the new library are realized at last. In addition, comparison is made betvveen the two libraries from another point of view and some expectation is made at the same time.