http://en.wikipedia.org/wiki/One-time_password, thanks Madhukar R Pai

VERSION

@@ -1 +1 @@
-Version 1.99.4 (2012-01-29 15:21:17) stable
+Version 1.99.4 (2012-01-29 15:22:07) stable

gluon/contrib/login_methods/motp_auth.py

@@ -0,0 +1,104 @@
+#!/usr/bin/env python
+
+import time
+from hashlib import md5
+from gluon.dal import DAL
+
+def motp_auth(db=DAL('sqlite://storage.sqlite'),
+              time_offset=60):
+              
+    """
+    motp allows you to login with a one time password(OTP) generated on a motp client, 
+    motp clients are available for practically all platforms.
+    to know more about OTP visit http://en.wikipedia.org/wiki/One-time_password
+    to know more visit http://motp.sourceforge.net
+    
+    
+    Written by Madhukar R Pai (madspai@gmail.com)
+    License : MIT or GPL v2
+    
+    thanks and credits to the web2py community
+    
+    to use motp_auth:
+    motp_auth.py has to be located in gluon/contrib/login_methods/ folder
+    first auth_user has to have 2 extra fields - motp_secret and motp_pin
+    for that define auth like shown below:
+    
+    ## after auth = Auth(db)
+    db.define_table(
+        auth.settings.table_user_name,
+        Field('first_name', length=128, default=''),
+        Field('last_name', length=128, default=''),
+        Field('email', length=128, default='', unique=True), # required
+        Field('password', 'password', length=512,            # required
+              readable=False, label='Password'),
+        Field('motp_secret',length=512,default='',
+              label='MOTP Seceret'),
+        Field('motp_pin',length=128,default='',
+              label='MOTP PIN'),
+        Field('registration_key', length=512,                # required
+              writable=False, readable=False, default=''),
+        Field('reset_password_key', length=512,              # required
+              writable=False, readable=False, default=''),
+        Field('registration_id', length=512,                 # required
+              writable=False, readable=False, default=''))
+              
+    ##validators
+    custom_auth_table = db[auth.settings.table_user_name] # get the custom_auth_table
+    custom_auth_table.first_name.requires = \
+      IS_NOT_EMPTY(error_message=auth.messages.is_empty)
+    custom_auth_table.last_name.requires = \
+      IS_NOT_EMPTY(error_message=auth.messages.is_empty)
+    custom_auth_table.password.requires = CRYPT()
+    custom_auth_table.email.requires = [
+      IS_EMAIL(error_message=auth.messages.invalid_email),
+      IS_NOT_IN_DB(db, custom_auth_table.email)]
+      
+    auth.settings.table_user = custom_auth_table # tell auth to use custom_auth_table
+    ## before auth.define_tables()
+    
+    ##after that:     
+    
+    from gluon.contrib.login_methods.motp_auth import motp_auth
+    auth.settings.login_methods.append(motp_auth(db=db))
+    
+    ##Instructions for using MOTP
+    - after configuring motp for web2py, Install a MOTP client on your phone (android,IOS, java, windows phone, etc)
+    - initialize the motp client (to reset a motp secret type in #**#), 
+      During user creation enter the secret generated during initialization into the motp_secret field in auth_user and
+      similarly enter a pre-decided pin into the motp_pin
+    - done.. to login, just generate a fresh OTP by typing in the pin and use the OTP as password
+    
+    ###To Dos###
+    - both motp_secret and pin are stored in plain text! need to have some way of encrypting
+    - web2py stores the password in db on successful login (should not happen)
+    - maybe some utility or page to check the otp would be useful
+    - as of now user field is hardcoded to email. Some way of selecting user table and user field.
+    """
+
+    def verify_otp(otp,pin,secret,offset=60):
+        epoch_time = int(time.time())
+        time_start = int(str(epoch_time - offset)[:-1])
+        time_end = int(str(epoch_time + offset)[:-1])
+        for t in range(time_start-1,time_end+1):
+            to_hash = str(t)+secret+pin
+            hash = md5(to_hash).hexdigest()[:6]
+            if otp == hash: return True
+        return False
+    
+    def motp_auth_aux(email,
+                      password,
+                      db=db,
+                      offset=time_offset):
+        if db:
+            user_data =  db(db.auth_user.email == email ).select().first()
+            if user_data:
+                if user_data['motp_secret'] and user_data['motp_pin']:
+                    motp_secret = user_data['motp_secret']
+                    motp_pin = user_data['motp_pin']
+                    otp_check = verify_otp(password,motp_pin,motp_secret,offset=offset)
+                    if otp_check: return True
+                    else: return False
+                else: return False
+        return False
+    return motp_auth_aux