processing openssl-encrypted files through pgdump and pgrestore

We run postgres 9.2.12

We've been given a mandate to encrypt all our database backups.

We also use the -f Fc subcommand in pgdump to create pg_restore suitable input/output files

The first step to create the encrypted dump works fine:

  pg_dump -U postgres auth_production_test -Fc | openssl enc -aes-256-cbc -kfile /home/postgres/.openssl.postgres.pass -e > /storage/backups/dbdumps/authproductiontest.custom.gz.enc &

However when I run pg_restore with the -l option to create the table of contents, pg_restore doesn't recognize the encrypted backup as a suitable archive:

Do I need to create an unencrypted dump first for pg_restore to recognize and act upon?  I don't see anything in the pg_restore documentation that allows for reading encrypted files. 

Any suggestions welcome.  Thanks,

--