Can I install Let's Encrypt in Aliyun ? Does China block it? or is there any restriction? is there any limit?
Hi and welcome to the community forum!
It does not appear that any particular certificate authority is being blocked by China.
China seems to be blocking only certain higher ciphers and protocols that can prevent interception.
Although there are two popular types of certs ECDSA/RSA, the certificate itself doesn't entirely dictate which cipher/protocol/algorithm must be used with it.
So, I suppose, that if you use an LE cert with an allowed cipher you should be able to use it (legally).
Before making any decision or taking any action you should always consult with the local authorities in that area about your use plan and their guidelines/regulations.
As far as LE limits, I believe those are set worldwide equally for all those that are allowed to use them.
To address this specific question: Can I install Let's Encrypt in Aliyun ?
I believe it is supported: https://developer.aliyun.com/mirror/npm/package/acme-v2
Of course if you can wait a few hours (as it is very early morning in the states), soon many more knowledgeable people will be reading this and responding to your questions.
My response is not a final answer.
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I think it's worth noting that there have been some issues with the GFW (perhaps inadvertently) blocking Let's Encrypt's OCSP servers in the past. This can affect the availability of your website.
It may not be an issue right now, I'm not sure.
Also (although this may be obvious to you if you're hosting a web site in China), some people on the forum have tried to get Let's Encrypt certificates for newly registered domains that were pointed at Chinese hosting providers which required an ICP license in order to comply with governmental regulations. Without the ICP license in place, the hosting providers wouldn't provide even minimal services for the domain necessary to obtain the certificate from the Let's Encrypt CA. Sometimes people on the forum have been confused by this.