diff --git a/kasserver/__init__.py b/kasserver/__init__.py
index 7f1364a..86d55c5 100644
--- a/kasserver/__init__.py
+++ b/kasserver/__init__.py
@@ -51,11 +51,8 @@ class KasServer:
         self._get_credentials()
 
     def _get_credentials(self):
-        def _sha1(string):
-            return None if not string else hashlib.sha1(string.encode()).hexdigest()
-
         self._username = os.environ.get("KASSERVER_USER", None)
-        self._auth_sha1 = _sha1(os.environ.get("KASSERVER_PASSWORD", None))
+        self._password = os.environ.get("KASSERVER_PASSWORD", None)
         if self._username:
             return
 
@@ -63,7 +60,7 @@ class KasServer:
         try:
             info = netrc.netrc().authenticators(server)
             self._username = info[0]
-            self._auth_sha1 = _sha1(info[2])
+            self._password = info[2]
         except (FileNotFoundError, netrc.NetrcParseError) as err:
             LOGGER.warning(
                 "Cannot load credentials for %s from .netrc: %s", server, err
@@ -72,8 +69,8 @@ class KasServer:
     def _request(self, request, params):
         request = {
             "KasUser": self._username,
-            "KasAuthType": "sha1",
-            "KasAuthData": self._auth_sha1,
+            "KasAuthType": "plain",
+            "KasAuthData": self._password,
             "KasRequestType": request,
             "KasRequestParams": params,
         }

diff --git a/tests/test_kasserver.py b/tests/test_kasserver.py
index ca18a2f..b7be822 100644
--- a/tests/test_kasserver.py
+++ b/tests/test_kasserver.py
@@ -36,7 +36,6 @@ LOGGER = logging.getLogger(__name__)
 
 USERNAME = "username"
 PASSWORD = "password"
-PASSWORD_SHA1 = "5baa61e4c9b93f3f0682250b6cf8331b7ee68fd8"
 
 # pylint: disable=protected-access
 # pylint: disable=attribute-defined-outside-init
@@ -56,7 +55,7 @@ class TestKasServerCredentials:
         netrc.side_effect = FileNotFoundError("")
         server = KasServer()
         assert server._username == USERNAME
-        assert server._auth_sha1 == PASSWORD_SHA1
+        assert server._password == PASSWORD
 
     @staticmethod
     @mock.patch.dict("os.environ", {})
@@ -66,7 +65,7 @@ class TestKasServerCredentials:
         netrc.return_value.authenticators.return_value = (USERNAME, "", PASSWORD)
         server = KasServer()
         assert server._username == USERNAME
-        assert server._auth_sha1 == PASSWORD_SHA1
+        assert server._password == PASSWORD
 
     @staticmethod
     @mock.patch.dict("os.environ", {})
@@ -76,7 +75,7 @@ class TestKasServerCredentials:
         netrc.side_effect = FileNotFoundError("")
         server = KasServer()
         assert not server._username
-        assert not server._auth_sha1
+        assert not server._password
 
 
 class TestKasServer:
@@ -186,8 +185,8 @@ class TestKasServer:
         kasserver._request(self.REQUEST_TYPE, self.REQUEST_PARAMS)
         request = {
             "KasUser": USERNAME,
-            "KasAuthType": "sha1",
-            "KasAuthData": PASSWORD_SHA1,
+            "KasAuthType": "plain",
+            "KasAuthData": PASSWORD,
             "KasRequestType": self.REQUEST_TYPE,
             "KasRequestParams": self.REQUEST_PARAMS,
         }

Switch from 'sha1' to 'plain' authentication method
The following E-Mail from All-Inkl support reached me today:

> Our system has detected that you are using the KAS API, which means that your custom scripts gain access to several features of the technical administration panel (KAS). So please forward the following information to the developer of those custom scripts as appropriate.
> 
> The authentication method "sha1" which is used by your custom scripts is deprecated and support for this authentication method will be gradually discontinued starting December 2022. In order to further use your custom scripts, an adjustment is necessary in the following accounts:
> 
> account : date of last sha1 authentication
> XXXXXXXX : 2022-08-01 22:19:25
> 
> Here's an example of how such a script code currently looks like: 
> 
> ```php
> $auth=array(
>  'kas_login' => 'XXXXXXXX',
>  'kas_auth_type' => 'sha1',
>  'kas_auth_data' => sha1('myPassword')
> )
> ```
> 
> Please alter your scripts in a way so that they use the new authentication method "plain" instead. An example how it should look afterwards: 
> 
> ```php
> $auth=array(
>  'kas_login' => 'XXXXXXXX',
>  'kas_auth_type' => 'plain',
>  'kas_auth_data' => 'myPassword'
> )
> ```
>
> You can find a full documentation of the KAS API under: 
> 
> http://kasapi.kasserver.com/dokumentation/phpdoc/
tests/test_kasserver.py::TestKasServerCredentials::test_getcredentials_from_env tests/test_kasserver.py::TestKasServerCredentials::test_getcredentials_from_netrc tests/test_kasserver.py::TestKasServerCredentials::test_getcredentials_failed_netrc tests/test_kasserver.py::TestKasServer::test_request
tests/test_kasserver.py::TestKasServer::test_request_failed tests/test_kasserver.py::TestKasServer::test_request_floodprotection tests/test_kasserver.py::TestKasServer::test_getdnsrecords tests/test_kasserver.py::TestKasServer::test_getdnsrecord tests/test_kasserver.py::TestKasServer::test_getdnsrecord_notfound tests/test_kasserver.py::TestKasServer::test_adddnsrecord tests/test_kasserver.py::TestKasServer::test_updatednsrecord tests/test_kasserver.py::TestKasServer::test_deletednsrecord tests/test_kasserver.py::TestKasServer::test_deletedbsrecord_notfound tests/test_kasserver.py::TestKasServerUtils::test_split_dqdn