The OpenPGP provider provides an interface to the OpenPGP cryptography software.
The library that interfaces to the OpenPGP cryptography software.
The GISB adapter does not by itself implement PGP, instead it uses the provider pattern to interface with external cryptography libraries. A OpenPGP provider is a simple module that allows the adapter to offload OpenPGP operations to the OpenPGP software of your choice. The interface is designed to be generic in its ability to include various OpenPGP software and is limited to only the bare minimum capabilities required for a GISB message exchange. We include an OpenPGP provider implementation for GnuPG which may be used as a reference to implement other providers.
An OpenPGP provider is simply a class called "nsoftwarePGPProvider" that should have the following
methods. The adapter uses reflection to access the methods of the provider.
public void SetParam(string name,string value); public byte Encrypt(byte data); public byte Decrypt(byte data); public byte Sign(byte data); public bool VerifySignature(byte signature,byte signedData);The PGPParams property is used to specify the parameters required by the OpenPGP provider to perform the OpenPGP operation. Although the parameters needed may vary in different providers, we expect the following set to be necessary. The reference GnuPG provider interprets the following parameters.
|1 (gpg-path)||The path to the OpenPGP executable for the desired implementation.|
|2 (homedir)||The directory containing the public keyring, secret keyring and trust database. Please note this defaults to the application preferences directory of the user, hence if the GNUPG provider is being used from a ASP.NET application, homedir should be specified.|
|3 (passphrase)||The passphrase to access the secret keys in the secret-keyring.|
|4 (userid)||The identifier used to identify a secret key within the secret-keyring.|
|5 (recipient-userid)||The identifier used to identify a public key within the public keyring.|
The adapter expects the encryption to return an ASCII armored output and the signing to compute a detached signature. Note: GnuPG is the Free Software Foundation's implementation of OpenPGP. It is free software and is recommended by NAESB (in version 1.6 of the EDM specification) for use in GISB/NAESB applications.
GnuPG is not included with this package, so you should download the latest version from http://www.gnupg.org. You might use GnuPG (or other software) to import your trading partners' public keys, and to import or generate a private key for yourself. These operations are outside the scope of this software, so please see the GnuPG documentation for details.