Bug 2073088
| Summary: | [systemd-resolved] SHA-1 DNSSEC signatures are broken in DEFAULT crypto-policy | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 9 | Reporter: | Petr Menšík <pemensik> |
| Component: | systemd | Assignee: | Michal Sekletar <msekleta> |
| Status: | CLOSED MIGRATED | QA Contact: | Frantisek Sumsal <fsumsal> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | CentOS Stream | CC: | bstinson, dtardon, jamacku, jmigacz, jwboyer, msekleta, systemd-maint-list |
| Target Milestone: | rc | Keywords: | Improvement, MigratedToJIRA, TestOnly, Triaged |
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2023-09-21 11:28:05 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 2138081 | ||
| Bug Blocks: | 2073066 | ||
(In reply to Petr Menšík from comment #0) > Description of problem: > Crypto policies in RHEL9 will block SHA-1 signatures by default. However RFC > 8624 [1] requires SHA-1 validation as mandatory. IOW, we have to support it but we can't... So what exactly is expected from us here? I think it should result in insecure response for SHA-1 algorithm on policies, where it would not pass verification. It should not make SHA-1 signed zones completely unavailable, but just considered like unsupported algorithm. Should not result in SERVFAIL, but just without AD flag in dns reply. That is the best way we can fix it. I am not sure how much resolved is supported in RHEL9, I just filled the bug to notify you there is some issue, which might need fix eventually. Adding also link to JIRA ticket, which provides a list of TLDs affected. This is still borked:
# rpm -q systemd
systemd-252-5.el9.x86_64
# grep ^DNSSEC= /etc/systemd/resolved.conf
DNSSEC=yes
# resolvectl query --cache=no ietf.org
ietf.org: resolve call failed: DNSSEC validation failed: failed-auxiliary
# update-crypto-policies --set DEFAULT:SHA1
Setting system policy to DEFAULT:SHA1
Note: System-wide crypto policies are applied on application start-up.
It is recommended to restart the system for the change of policies
to fully take place.
# systemctl restart systemd-resolved
# resolvectl query --cache=no ietf.org
ietf.org: 2001:559:c4c7::100 -- link: eth0
50.223.129.194 -- link: eth0
-- Information acquired via protocol DNS in 6.2ms.
-- Data is authenticated: yes; Data was acquired via local or encrypted transport: no
-- Data from: network
Issue migration from Bugzilla to Jira is in process at this time. This will be the last message in Jira copied from the Bugzilla bug. This BZ has been automatically migrated to the issues.redhat.com Red Hat Issue Tracker. All future work related to this report will be managed there. Due to differences in account names between systems, some fields were not replicated. Be sure to add yourself to Jira issue's "Watchers" field to continue receiving updates and add others to the "Need Info From" field to continue requesting information. To find the migrated issue, look in the "Links" section for a direct link to the new issue location. The issue key will have an icon of 2 footprints next to it, and begin with "RHEL-" followed by an integer. You can also find this issue by visiting https://issues.redhat.com/issues/?jql= and searching the "Bugzilla Bug" field for this BZ's number, e.g. a search like: "Bugzilla Bug" = 1234567 In the event you have trouble locating or viewing this issue, you can file an issue by sending mail to rh-issues. You can also visit https://access.redhat.com/articles/7032570 for general account information. |
Description of problem: Crypto policies in RHEL9 will block SHA-1 signatures by default. However RFC 8624 [1] requires SHA-1 validation as mandatory. Because crypto policy is mandatory, it will affect any DNSSEC validating software using openssl or gnutls. Version-Release number of selected component (if applicable): openssl-libs-3.0.1-21.el9.x86_64 crypto-policies-20220223-1.git5203b41.el9_0.1.noarch gnutls-3.7.3-9.el9.x86_64 How reproducible: reliable Steps to Reproduce: 1. set DNSSEC=yes in /etc/systemd/resolved.conf 2. systemctl restart systemd-resolved 3. resolvectl query ietf.org Actual results: ietf.org: resolve call failed: DNSSEC validation failed: failed-auxiliary Expected results: ietf.org: 2001:1900:3001:11::2c -- link: eth0 4.31.198.44 -- link: eth0 -- Information acquired via protocol DNS in 1.0828s. -- Data is authenticated: yes; Data was acquired via local or encrypted transport: no -- Data from: network Additional info: command "update-crypto-policies --set DEFAULT:SHA1" will switch to crypto policy, which would allow previous behaviour and success of both signature verification and creation. 1. https://datatracker.ietf.org/doc/html/rfc8624#section-3.1