1 files changed, 61 insertions, 0 deletions
diff --git a/src/ssh_audit/algorithm.py b/src/ssh_audit/algorithm.py
new file mode 100644
index 0000000..e213264
--- /dev/null
+++ b/src/ssh_audit/algorithm.py
@@ -0,0 +1,61 @@
+"""
+   The MIT License (MIT)
+
+   Copyright (C) 2017 Andris Raugulis (moo@arthepsy.eu)
+
+   Permission is hereby granted, free of charge, to any person obtaining a copy
+   of this software and associated documentation files (the "Software"), to deal
+   in the Software without restriction, including without limitation the rights
+   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+   copies of the Software, and to permit persons to whom the Software is
+   furnished to do so, subject to the following conditions:
+
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+   THE SOFTWARE.
+"""
+# pylint: disable=unused-import
+from typing import Dict, List, Set, Sequence, Tuple, Iterable  # noqa: F401
+from typing import Callable, Optional, Union, Any  # noqa: F401
+
+from ssh_audit.product import Product
+
+
+class Algorithm:
+
+    @staticmethod
+    def get_ssh_version(version_desc: str) -> Tuple[str, str, bool]:
+        is_client = version_desc.endswith('C')
+        if is_client:
+            version_desc = version_desc[:-1]
+        if version_desc.startswith('d'):
+            return Product.DropbearSSH, version_desc[1:], is_client
+        elif version_desc.startswith('l1'):
+            return Product.LibSSH, version_desc[2:], is_client
+        else:
+            return Product.OpenSSH, version_desc, is_client
+
+    @classmethod
+    def get_since_text(cls, versions: List[Optional[str]]) -> Optional[str]:
+        tv = []
+        if len(versions) == 0 or versions[0] is None:
+            return None
+        for v in versions[0].split(','):
+            ssh_prod, ssh_ver, is_cli = cls.get_ssh_version(v)
+            if not ssh_ver:
+                continue
+            if ssh_prod in [Product.LibSSH]:
+                continue
+            if is_cli:
+                ssh_ver = '{} (client only)'.format(ssh_ver)
+            tv.append('{} {}'.format(ssh_prod, ssh_ver))
+        if len(tv) == 0:
+            return None
+        return 'available since ' + ', '.join(tv).rstrip(', ')