* feat: Change Postfix smtpd_tls key and cert files to chain_files
Since Postfix 3.4, `smtpd_tls_cert_file` and `smtpd_tls_key_file` have been deprecated in favor of `smtpd_tls_chain_files` which supports a list of values where a single or sequence of file paths provide a private key followed by it's certificate chain.
* feat: Dual certificate support
`smtpd_tls_chain_files` allows for multiple key+cert bundles so that you can provide different key types, such as ECDSA and RSA.
To maintain compatibility with the current CERT/KEY ENV vars only a 2nd certificate is supported.
Since Dovecot 2.2.31 a related feature is also available, but it is limited to only providing one alternative certificate via separate cert and key settings.
---
This feature enables support for multiple certificates, eg for serving modern ECDSA certs with RSA as fallback.
* chore: Refactor variable names to meet style guide
Improved some comments too.
* chore: Have function definitions respect style guide
* chore: Minor edits to comments
* chore: Expand on comments for maintenance, alert of insecure config
When `SSL_TYPE` isn't properly setup, we're still offering SSL connections but not warning in logs about the insecurity of such, or why a misconfiguration may have occurred.
This commit more clearly communicates to the user that they should look into the issue before considering deploying to production.
The `TODO` comments communicate to any future maintainer to consider treating these improper configs as disabling TLS instead.
* fix: Use `snakeoil` cert
I mistakenly thought this was placeholder text, which broke some tests. This adds the two files in the correct order (private key followed by cert/chain), to fix that issue.
* fix: Disable alt cert for Dovecot if necessary
Certain scenarios may persist state of previously configured alt cert via ENV vars that are removed from a future run. If the config is not reset to original immutable state, this will correctly disable the config from using alt cert unintentionally.
* fix: Satisfy ShellCheck lint
By switching from string var to array / list expansion, this better stores the extracted result and applies it in a manner that ShellCheck linting approves, removing the need to disable the rule.
* feat: Support dual cert test
Few tweaks to the test script allows re-purposing it for covering dual cert support as well.
* chore: Rearranged cert and key lines
A little reorganization, mostly placing private key ahead of related cert lines.
* chore: Refactor `_set_certificate`
This should make the parameters a little less confusing.
Previously was 3 parameters, but the Postfix parameter (1st) may look like two variables if you don't pay attention to the surrounding quotes; while the Dovecot parameters (2nd + 3rd) would have an opposing order. There was also a variant where the `FULLKEYCHAIN` var was passed in three times.
Now it's two params, with the 2nd param as an optional one. If the 2nd param is provided, then the two params are in the order of private key then certificate, otherwise if only a single parameter it's a single PEM file with the full cert chain and private key bundled.
This avoids implying that Postfix and Dovecot might use different files.
* chore: Document current state of `SSL_TYPE` logic better
Inlined for the benefit of anyone else maintaining this section if I'm unable to address the concerns within my own time.
* docs: ENV vars
`TLS_LEVEL=old` isn't in the codebase anymore, not likely to be relevant to retain.
No point in documenting what is considered invalid / unsupported config value in the first place for `SSL_TYPE`.
`SSL_TYPE=manual` was missing documentation for both related file path ENV vars, they've been added along with their alt fallback variants.
* chore: Update Dovecot LMTP SSL test config
Not sure how relevant this is, the file isn't complete sync with the main dovecot `10-ssl.conf` config, adding the support just in case.
* chore: Rename `FULLKEYCHAIN` to avoid confusion
There doesn't appear to be a standardized name for this type of file bundle, and `keychain` may be misleading (fullkeychain often provides macOS keychain results on search engines).
Opting for a more explicit `KEY_WITH_FULLCHAIN` name instead.
* fix: Invalid var name
`_set_certificate` refactor commit accidentally changed a var name and committed that breaking the dual cert support (thanks tests!).
* test: Refactor `mail_ssl_manual.bats`
Proper test return values instead of `wc -l` based checking.
Tests with dual cert support active, tests that feature (to better detect failure case.
Third test case was unable to verify new self-signed certificate, added new certs signed with self-signed root CA.
Adjusted openssl `CApath` parameter to use `CAfile` instead as `letsencrypt` cert was replaced thus CA cert is missing from the system trust store.
* test: Properly check for files in `mail_ssl_manual.bats`
Fixes lint error.
Also realized I was accidentally asserting a file exists in the test environment, not within the container.
Resolved that and also added an additional test case to ensure the ENV var files are valid when passed in, in the event a change misconfigures them and that the issue is identified earlier.
* chore: Apply PR review feedback
Better format some strings that had mixed quotes when they weren't necessary.
Additionally DRYed up the config path for Postfix and Dovecot within the `_setup_ssl` method.
Co-authored-by: Georg Lauterbach <infrastructure@itbsd.com>
* remove two ciphers according to https://www.htbridge.com/ssl/ (NIST, HIPAA)
* added a switch via an environment variable to choose between modern and intermediate ciphers
* install dovecot from backports
* dovecot 2.2.33 has a slightly different TLS-configuration than 2.2.27
* want to have both images a the same time
* make use of the /etc/dovecot/ssl as mkcert.sh (2.2.33) is using that folder for certs.
* Switch to stretch-slim as base image.
- first step correct the testdata, as newer packages are more strict
about the mail-structure.
* Switch to stretch-slim: correcting the test-environment and the build
- add missing build-step to make
- clean the userdb aswell
- use timeout of netcat, as postgrey would not close the connection
- there is 2 extra mail-logs -> assert_output 5
- cosmetic: use "" instead of ''
* Switch to stretch-slim:
new image:
- smaller size
- 0 CVEs compared to 11 CVEs in ubuntu 16.04 Image
better backport situation
- postfix 3.1.6 vs 3.1.0
- fail2ban 0.9.6 vs 0.9.3
...
changes needed because of stretch-slim:
- add missing gnupg and iproute2 package
- remove non-free rar, unrar-free should do
- rsyslog does not add syslog user and has different conf-structure
- pyzor command discover was deprecated and is missing in the new
stretch package
- dovecot does not know SSLv2 anymore. removed because of warnings in
log
- iptables does not know imap3, IMAP working group chose imap2 in favor
of imap3
* Switch to debian stretch slim:
SSLv2 seems to be a not known protocol anymore - good!
* switch to debian stretch slim:
make this test more stable. there might be more than only one mail.log
(mail.info, mail.warn, ...)
* switch to debian stretc slim:
new openssl 1.1.0 needs stronger ciphers, removed some weekers ones.
Please, look through the new list of cipher! this needs to be done in
another commit for all other SSL/TLS-Endpoints aswell.
* Switch to debian stretch slim:
let our server pre-empt the cipher list.
Did a read through, wwwDOTpostfixDOTorg/FORWARD_SECRECY_READMEDOThtml
and
wwwDOTpostfixDOTorg/TLS_READMEDOThtml
* Switch to debian stretch slim: lets give this openssl-based test a new and independent but identical container. many other test on the main 'mail' container might interfere here.
* Switch to debian stretch slim: remove unused lines
Brennan Kinney
youtous
Erik Wramner
Marek Walczak
Kai Ren
Thomas VIAL
Daniele Bellavista
Sylvain Dumont