Recently I discovered that all images was gone (not showing) from our phabricator instance. It all traces back to the fact that every file in the files-application thorws an exception stating that “HMAC-SHA256 can only digest strings”. We’re using an S3 bucket as backend.
Upload a file to the files application
Try to retrieve it
Get Unhandled Exception (“Exception”): HMAC-SHA256 can only digest strings.
0c3f59fd688a5488cadfb9286d11fbedff766d5d (Wed, Sep 4) (branched from 533a5535b6f0104c13266400735cb563d64525e7 on origin)
feb5f4d42c4fe0001e76428e80d5e88262308802 (Jun 22 2019) (branched from d92fa96366c0ed50e4257508148aa75192d4fb1f on origin)
794ded9857110cdc7b0fb7bedb4a64438d2d873e (Sat, Aug 31) (branched from 71e8d7a4cf8e9f56b1427c27b3684ae17a3ea7c7 on origin)
Our setup is using the S3 API implemented in Openstack Swift, and our Swift installation was temporarly unavailable, causing all of phabricator’s attempts to retrieve data to fail with an http 404 error… Maybe you can replicate it by setting up a working S3 configuration, store some files and then delete them in S3 “manually” (outside of phabricator)?