I am getting an empty reply when using either GET or POST (and updates are not working):
$ curl -u penurio.us:XXXXXXXXXXXXXXXX -v 'https://dyn.dns.he.net/nic/update?hostname=penurio.us&myip=70.119.136.2'
* Trying 184.105.242.3...
* TCP_NODELAY set
* Connected to dyn.dns.he.net (184.105.242.3) port 443 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb
* CAfile: /etc/pki/tls/certs/ca-bundle.crt
CApath: none
* ALPN, server accepted to use http/1.1
* SSL connection using TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
* Server certificate:
* subject: CN=dyn.dns.he.net
* start date: Jul 01 16:30:00 2017 GMT
* expire date: Sep 29 16:30:00 2017 GMT
* common name: dyn.dns.he.net
* issuer: CN=Let's Encrypt Authority X3,O=Let's Encrypt,C=US
* Server auth using Basic with user 'penurio.us'
> GET /nic/update?hostname=penurio.us&myip=70.119.136.2 HTTP/1.1
> Host: dyn.dns.he.net
> Authorization: Basic cGVudXJpby51czpHajRQWjNvSmlUckk1Q0RJ
> User-Agent: curl/7.51.0
> Accept: */*
>
* Curl_http_done: called premature == 0
* Empty reply from server
* Connection #0 to host dyn.dns.he.net left intact
curl: (52) Empty reply from server
$ curl -u penurio.us:XXXXXXXXXXXXXXXX -v 'https://dyn.dns.he.net/nic/update' -d 'hostname=penurio.us' -d 'myip=70.119.136.2'
* Trying 184.105.242.3...
* TCP_NODELAY set
* Connected to dyn.dns.he.net (184.105.242.3) port 443 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb
* CAfile: /etc/pki/tls/certs/ca-bundle.crt
CApath: none
* ALPN, server accepted to use http/1.1
* SSL connection using TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
* Server certificate:
* subject: CN=dyn.dns.he.net
* start date: Jul 01 16:30:00 2017 GMT
* expire date: Sep 29 16:30:00 2017 GMT
* common name: dyn.dns.he.net
* issuer: CN=Let's Encrypt Authority X3,O=Let's Encrypt,C=US
* Server auth using Basic with user 'penurio.us'
> POST /nic/update HTTP/1.1
> Host: dyn.dns.he.net
> Authorization: Basic cGVudXJpby51czpHajRQWjNvSmlUckk1Q0RJ
> User-Agent: curl/7.51.0
> Accept: */*
> Content-Length: 37
> Content-Type: application/x-www-form-urlencoded
>
* upload completely sent off: 37 out of 37 bytes
* Curl_http_done: called premature == 0
* Empty reply from server
* Connection #0 to host dyn.dns.he.net left intact
curl: (52) Empty reply from server