This is a hackish tool to export Messages and attachments from an unencrypted iPhone backup. I've only tested it on my backup (which contains messages that date back to 2010ish) with

• iOS 14.7 on macOS 11.5
• iOS 15.5 on macOS 11.6

This is meant as a starting point for other people who want to hack around with their backups and not as a finished product of any kind, although it may work the first time for you.

It's my first time using SQL so undoubtedly some of the queries could be run more efficiently. However, the limiting factor seems to be the bandwidth of copying files rather than the queries themselves (and/or the statting which is less than optimal). But this is supposed to be run maybe once a year at most when you want to export your messages, rather than repeatedly.

The output is a series of directories named after the chat identifier (usually the recipient's message handle or chatNNN... for group), inside of which is a JSON messages file. Attachments are copied from the decrypted backup to a subdirectory inside each chat.

This requires at least Python 3.6, and probably 3.7.

Usage:

$ python3 export.py "~/Library/Application Support/MobileSync/Backup/...."
"~/Desktop/iphone-export"