UID Authenticator

brmdoor_authenticator.py

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+import sqlite3
+
+class UidRecord(object):
+	"""Represents UID<->nick pair"""
+	
+	def __init__(self, uid_hex, nick):
+		"""
+		Create instance binding UID to nick. UIDs should be either 4, 7
+		or 10 bytes long, but that's ISO14443 thing - this object has
+		no such limitation.
+		
+		UID will be stored in uppercase hex, converted if necessary.
+		
+		@param uid_hex: uid in hex
+		@param nick: nickname this UID belongs to
+		"""
+		self.uid_hex = uid_hex.upper()
+		self.nick = nick
+	
+	def __str__(self):
+		return "(uid: %s, nick: %s)" % (self.uid_hex, self.nick)
+	
+	def __repr__(self):
+		return "<UidRecord: uid: %s, nick: %s>" % (self.uid_hex, self.nick)
+
+class UidAuthenticator(object):
+	"""Checks UIDs of ISO14443 RFID cards against database."""
+	
+	def __init__(self, filename):
+		"""
+		Connects to database by given filename and later checks UIDs
+		against that database.
+		"""
+		#open in autocommit mode - we are not changing anything
+		self.conn = sqlite3.connect(filename, isolation_level=None)
+
+	def fetchUidRecord(self, uid_hex):
+		"""
+		Returns first record that matches given UID or None if nothing
+		is found.
+		
+		@param uid_hex: uid to match in hex
+		@returns UidRecord instance if found, None otherwise
+		"""
+		cursor = self.conn.cursor()
+		sql = "SELECT nick FROM authorized_uids WHERE UPPER(uid_hex)=?"
+		sql_data =(uid_hex.upper(),)
+		
+		cursor.execute(sql, sql_data)
+		record = cursor.fetchone()
+		
+		if record is None:
+			return None
+		
+		nick = record[0]
+		return UidRecord(uid_hex, nick)
+	
+	def shutdown(self):
+		"""Closes connection to database"""
+		self.conn.close()
+
+
+#test routine
+if __name__ == "__main__":
+	authenticator = UidAuthenticator("test_uids_db.sqlite")
+	
+	record = authenticator.fetchUidRecord("043a1482cc2280")
+	print "For UID 043a1482cc2280 we found:", str(record)
+	
+	record = authenticator.fetchUidRecord("34795fad")
+	print "For UID 34795fad we found:", str(record)
+	
+	record = authenticator.fetchUidRecord("01020304")
+	print "For UID 01020304 we found:", str(record)
+	
+	authenticator.shutdown()

create_authenticator_db.py

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+#!/usr/bin/env python
+
+"""
+Creates and empty sqlite database file for brmdoor_authenticator.UidAuthenticator.
+
+Give filename as first argument.
+"""
+
+import sys
+import sqlite3
+
+if __name__ == "__main__":
+	if len(sys.argv) < 2:
+		print >> sys.stderr, "You must specify filename as arg1 where the DB is to be created"
+	
+	filename = sys.argv[1]
+	conn = sqlite3.connect(filename)
+	cursor = conn.cursor()
+	
+	cursor.execute("CREATE TABLE authorized_uids(uid_hex, nick)")
+	conn.commit()
+	conn.close()