Lego - Let's Encrypt client and ACME library

Let's Encrypt client and ACME library written in Go.

Its feature include:

• Register with CA
• Obtain certificates, both from scratch or with an existing CSR
• Renew certificates
• Revoke certificates
• Robust implementation of all ACME challenges
  • HTTP (http-01)
  • TLS with Server Name Indication (tls-sni-01)
  • DNS (dns-01)
• SAN certificate support
• Comes with multiple optional DNS providers
• Custom challenge solvers
• Certificate bundling
• OCSP helper function