Bug ID: 1127591 Summary: zypper option "ssl_capath" not working for mirror URLs from metalink file Classification: openSUSE Product: openSUSE Distribution Version: Leap 15.0 Hardware: x86-64 OS: SUSE Other Status: NEW Severity: Normal Priority: P5 - None Component: libzypp Assignee: firstname.lastname@example.org Reporter: email@example.com QA Contact: firstname.lastname@example.org CC: email@example.com Found By: --- Blocker: ---
Using zypper (version: 1.14.12) for the update repository of openSUSE Leap 15.0 with the option
does not use the here configured trusted root certificates for mirror URLs, probably retrieved from a metalink file.
The configured path is used for the initial connection to download.opensuse.org but following requests to mirrors seem to fallback to the system trusted certs from /etc/ssl/certs.
If the mirrors' root CA is trusted in "ssl_capath=/path/to/directory/with/c_rehash/rootCAs" but not in /etc/ssl/certs, zypper,libzypp, multi-curl or something else aborts the TLS-Handshake with failure "Unknown CA (48)" and falls futher back to http (without transport layer encryption).
Question for cc'ed security-team to answer: If using clear text is considered a security flaw where zypper is configured to use (https-)encryption, this might have security implications.
Assume download.opensuse.org is signed by CA A and the mirror by CA B
Assume further, ssl_capath=/path/to/directory/with/c_rehash/rootCAs is directory C
and directory D is /etc/ssl/certs
1. If C includes A and B and in D at least B is not available, I would expect zypper to encrypt both connection, but the request to the mirror is not.
2. If A is not in C, no data (meta link file) is retrieved and therefore no mirror is connected - Good! No fallback of looking for A in D occurs.
3. If A is in C and B in D, both connections are encrypted.
4. If A is in C and B not in C and not in D, the mirror is contacted unencrypted - here I'm unsure if using plain text in this scenario is correct or if it should fail.
So, in my opinion, 1. is the bug, 3. a workaround and 4. perhaps needs a zypper option to configure, if clear text fallback should be allowed.
Another question is, if /etc/ssl/certs should actually be consulted when the option "ssl_capath" is used and pointing to a different directory.
https://bugzilla.opensuse.org/show_bug.cgi?id=933839 might be related (similar setup). Problem and solution might be similar, too.
By the way, is there a debugging option to dump the traffic from inside the encrypted connection? Especially being able to read the metalink file with the listed mirrors is of interest.