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Handle multi-file OpenPGP archives
Essentially, OpenPGP messages containing multiple files are processed in exactly same way as generic single-file OpenPGP archives. The only difference is that you have to be prepared to handle the multi-file scenario correctly, so that all the files were extracted to the right locations.
First, handle the OnMultipleFilesFound event. It will notify you whether the message you passed to DecryptAndVerify() contains multiple files. It also allows you to stop any further processing if you are not prepared to handle such scenarios.
Next, implement the OnCreateOutputStream event handler to correctly handle the situation where multiple files can be present. This event will be fired for all files present in the archive one-by-one, so, for example, hard-coding the destination path might not be as good idea as it may with single-file archives.
Handle OnTemporaryStream event. This event may be fired by TAR format processing engine to store the decrypted TAR data when extracting individual files.
That's it. The rest of setup (encrypted data processing, signature processing) is performed in exactly same way as you do with single-file OpenPGP archives. Note that any signatures included in multi-file archives cover the whole archive and not the individual files.
How To articles about file encryption and signing with OpenPGP
