[Bug] HA 2025.10 breaks Daikin due to SSL errors

[ulnic]

The problem
With the latest HA 2025.10.1 (likely also 2025.10.0), Daikin no longer connects. Instead this gives the below error message which only started to appear from this version.

Failed setup, will retry: Cannot connect to host 192.168.10.120:443 ssl:<ssl.SSLContext object at 0x7f646ea8bed0> [[SSL: WRONG_SIGNATURE_TYPE] wrong signature type (_ssl.c:1032)]

What version of Home Assistant Core has the issue?
core-2025.10.1

What was the last working version of Home Assistant Core?
core-2025.9.x

What type of installation are you running?
Home Assistant Docker

Integration causing the issue
Daikin AC

Other notes:
Other users started to report this as well, and confirmed that downgrading to 2025.09 restored this functionality, e.g. https://community.home-assistant.io/t/2025-10-undo-redo-and-draw-me-too/936078/112?u=menic

Screenshots:

[Dan5672]

Did 2025.10.0 update OpenSSL? I'm getting errors that the Key Exchange (DH 1024) is lower strength than the certificate key.
Daikin might need to fix this and issue a firmware update.

[channafam]

I too have the same issue. Was driving me mad thinking that the issue was on my end however this post highlights the exact same issue ob my end

ClientConnectorSSLError: Cannot connect to host 192.168.20.180:443 ssl:<ssl.SSLContext object at 0x7f0b1ac0f750> [[SSL: WRONG_SIGNATURE_TYPE] wrong signature type (_ssl.c:1032)].

[flowconic]

Did 2025.10.0 update OpenSSL? I'm getting errors that the Key Exchange (DH 1024) is lower strength than the certificate key.
Daikin might need to fix this and issue a firmware update.

Not sure. How to check?

[ulnic]

great news, daikin is working again in home assistant 2025.10.2 for me!

[channafam]

Mine too - thanks guys !!!