services: minimal services.txt-over-ssh provider (twisted)

1 files changed, 25 insertions, 0 deletions

diff --git a/services/checkers.py b/services/checkers.py
new file mode 100644
index 00000000..dbfe1323
--- /dev/null
+++ b/services/checkers.py
@@ -0,0 +1,25 @@
+
+import base64, binascii
+from twisted.python.filepath import FilePath
+from twisted.conch.checkers import SSHPublicKeyDatabase
+
+
+class PublicKeyChecker(SSHPublicKeyDatabase):
+
+    def __init__(self, filename):
+        self.filepath = FilePath(filename)
+
+    def getAuthorizedKeysFiles(self, credentials):
+        return [self.filepath]
+
+    def checkKey(self, credentials):
+        for line in self.filepath.open():
+            parts = line.split()
+            if len(parts) < 2:
+                continue
+            try:
+                if base64.decodestring(parts[1]) == credentials.blob:
+                    return True
+            except binascii.Error:
+                continue
+        return False