DDNS auto certification import from ASUSWRT integration

[vanarebane]

Hi,
I already started to research on how I could make this feature myself, but I don't have experience with Home Assistant development environment. But..

Here is my idea:
I have DDNS enabled on my Asus router and the certification is issued by Let's Encrypt. That means, that every 3 months I have to manually export the certification from the router webadmin and copy it to the HA ssl folder.

So I found this HA Integration/component ASUSWRT, that currently gets' usage data from the ASUS router. I poked around the source code of this component and I see that it's getting all the data from the routers SSH console lines.

I formulated this automation:

1. HA checks from the router if DDNS is enabled
2. If enabled, get the DDNS config from /jffs/.le/{domain}/{domain}.conf
   2.1. The {domain} here should be the domain that the certification is issued to. I'm not sure what does this look like to others, but mine was [Host Name].asuscomm.com
3. If the component is running the first time, jump to step 7
4. From the config file, read Le_NextRenewTime and compare to the saved variable, CurrentCertCreateTime
5. If the Le_NextRenewTime is greater than the saved CurrentCertCreateTime variable, jump to step 7
6. Else (nothing to update now) jump to End
7. Copy the SSL from router to HA
   7.1. From the config file variable Le_RealKeyPath directs to a file that is certification. Copy it's content to HA folder ssl/cert.pem (I named it so, but the file name and location can vary, so there must be a option to configure it)
   7.2. From the config file variable Le_RealFullChainPath directs to a file that is key. Copy it's content to HA folder ssl/key.pem (same story as with the cert.pem)
   7.3 Save the variable CurrentCertCreateTime the certification end date . That is from the config file Le_NextRenewTime
8. End

I will poke at this again at some time. If there are no developers available for this feature right now maybe someone can leave hints where could I start to write this feature myself. Thanks!