The rpm-sequoia library provides an implementation of the rpm's pgp
interface using Sequoia.

This library's crypto policy can be customized.  It finds the
configuration file by checking the following in turn:

- the `RPM_SEQUOIA_CRYPTO_POLICY` environment variable,
- `/etc/crypto-policies/back-ends/rpm-sequoia.config`,
- the `SEQUOIA_CRYPTO_POLICY` environment variable, and finally,
- `/etc/crypto-policies/back-ends/sequoia.config`.

Only the first configuration file that is present is used.  If an
environment is set to the empty string, then an empty configuration
file is used.  That is, the default policy is used.

Thus, if `RPM_SEQUOIA_CRYPTO_POLICY` is not set, and
`/etc/crypto-policies/back-ends/rpm-sequoia.config`, the latter will
be used.  In this case, `SEQUOIA_CRYPTO_POLICY` and
`/etc/crypto-policies/back-ends/sequoia.config` will be completely
ignored.