Lets-Encrypt
 Links
Examples
- Renew:
./letsencrypt-auto renew
 
- 
ACME Tiny
 
python acme-tiny/acme_tiny.py --directory-url https://acme-staging-v02.api.letsencrypt.org/directory --account-key ./account.key --csr ./domain.csr --acme-dir /var/www/challenges/ > ./signed_chain.crt 
python acme-tiny/acme_tiny.py --account-key ./account.key --csr ./domain.csr --acme-dir /var/www/challenges/ > ./signed_chain.crt 
- ACME client: https://github.com/diafygi/acme-tiny
 
- Staging environment:
https://letsencrypt.org/docs/staging-environment/