Use of ACMEDirectory instead of CAUrl part 2/3

This part use ACMEDirectory in requests to ACME server.
Next part will remove last remaining CAUrl code and enable dynamic agreement url.

acme_dns_tiny.py

@@ -52,6 +52,10 @@ def get_crt(config, log=LOGGER):
         except IOError as e:
             return getattr(e, "code", None), getattr(e, "read", e.__str__)(), None
 
+    # get ACME server configuration from the directory
+    directory = urlopen(config["acmednstiny"]["ACMEDirectory"])
+    acme_config = json.loads(directory.read().decode("utf8"))
+
     # create DNS keyring and resolver
     log.info("Prepare DNS tools...")
     keyring = dns.tsigkeyring.from_text({config["TSIGKeyring"]["KeyName"]: config["TSIGKeyring"]["KeyValue"]})
@@ -122,7 +126,7 @@ def get_crt(config, log=LOGGER):
         log.info("Verifying {0}...".format(domain))
 
         # get new challenge
-        code, result, headers = _send_signed_request(config["acmednstiny"]["CAUrl"] + "/acme/new-authz", {
+        code, result, headers = _send_signed_request(acme_config["new-authz"], {
             "resource": "new-authz",
             "identifier": {"type": "dns", "value": domain},
         })
@@ -194,7 +198,7 @@ def get_crt(config, log=LOGGER):
     # get the new certificate
     log.info("Signing certificate...")
     csr_der = _openssl("req", ["-in", config["acmednstiny"]["CSRFile"], "-outform", "DER"])
-    code, result, headers = _send_signed_request(config["acmednstiny"]["CAUrl"] + "/acme/new-cert", {
+    code, result, headers = _send_signed_request(acme_config["new-cert"], {
         "resource": "new-cert",
         "csr": _b64(csr_der),
     })

tests/acme_account_delete.py

@@ -57,9 +57,13 @@ def delete_account(accountkeypath, log=LOGGER):
         },
     }
     
+    # get ACME server configuration from the directory
+    directory = urlopen(ACMEDirectory)
+    acme_config = json.loads(directory.read().decode("utf8"))
+    
     # send request to delete account key
     log.info("Delete account...")
-    code, result = _send_signed_request(CAURL + "/acme/new-reg", {
+    code, result = _send_signed_request(acme_config["new-reg"], {
         "resource": "reg",
         "delete": True,
     })