webapi-eca/coffee/db_interface.coffee
2013-11-21 22:07:39 +01:00

381 lines
10 KiB
CoffeeScript

###
DB Interface
============
>Handles the connection to the database and provides functionalities for
>event/action modules, rules and the encrypted storing of authentication tokens.
>General functionality as a wrapper for the module holds initialization,
>encryption/decryption, the retrieval of modules and shut down.
>
>The general structure for linked data is that the key is stored in a set.
>By fetching all set entries we can then fetch all elements, which is
>automated in this function.
>For example modules of the same group, e.g. action modules are registered in an
>unordered set in the database, from where they can be retrieved again. For example
>a new action module has its ID (e.g 'probinder') first registered in the set
>'action_modules' and then stored in the db with the key 'action\_module\_' + ID
>(e.g. action\_module\_probinder).
>
###
'use strict'
### Grab all required modules ###
redis = require 'redis'
crypto = require 'crypto'
log = require './logging'
crypto_key = null
db = null
###
##Module call
Initializes the DB connection. Requires a valid configuration file which contains
a db port and a crypto key.
@param {Object} args
###
exports = module.exports = (args) ->
args = args ? {}
log args
config = require './config'
config args
crypto_key = config.getCryptoKey()
db = redis.createClient config.getDBPort(), 'localhost', { connect_timeout: 2000 }
db.on "error", (err) ->
err.addInfo = 'message from DB'
log.error 'DB', err
###
Checks whether the db is connected and passes either an error on failure after
ten attempts within five seconds, or nothing on success to the callback(err).
@public isConnected( *cb* )
@param {function} cb
###
#}TODO check if timeout works with func in func
exports.isConnected = (cb) ->
if db.connected then cb()
else
numAttempts = 0
fCheckConnection = ->
if db.connected
log.print 'DB', 'Successfully connected to DB!'
cb()
else if numAttempts++ < 10
setTimeout fCheckConnection, 500
else
e = new Error 'Connection to DB failed!'
log.error 'DB', e
cb e
setTimeout fCheckConnection, 500
###
Encrypts a string using the crypto key from the config file, based on aes-256-cbc.
@private encrypt( *plainText* )
@param {String} plainText
###
encrypt = (plainText) ->
if !plainText? then return null
try
enciph = crypto.createCipher 'aes-256-cbc', crypto_key
et = enciph.update plainText, 'utf8', 'base64'
et + enciph.final 'base64'
catch err
err.addInfo = 'during encryption'
log.error 'DB', err
null
###
Decrypts an encrypted string and hands it back on success or null.
@private decrypt( *crypticText* )
@param {String} crypticText
###
decrypt = (crypticText) ->
if !crypticText? then return null;
try
deciph = crypto.createDecipher 'aes-256-cbc', crypto_key
dt = deciph.update crypticText, 'base64', 'utf8'
dt + deciph.final 'utf8'
catch err
err.addInfo = 'during decryption'
log.error 'DB', err
null
###
Abstracts logging for simple action replies from the DB.
@private replyHandler( *action* )
@param {String} action
###
replyHandler = (action) ->
(err, reply) ->
if err
err.addInfo = 'during "' + action + '"'
log.error 'DB', err
else
log.print 'DB', action + ': ' + reply
###
Fetches all linked data set keys from a linking set, fetches the single data objects
via the provided function and returns the results to the callback(err, obj) function.
@private getSetRecords( *set, fSingle, cb* )
@param {String} set the set name how it is stored in the DB
@param {function} fSingle a function to retrieve a single data element per set entry
@param {function} cb the callback(err, obj) function that receives all the retrieved data or an error
###
getSetRecords = (set, funcSingle, cb) ->
db?.smembers set, (err, arrReply) ->
if err
err.addInfo = 'fetching ' + set
log.error 'DB', err
else if arrReply.length == 0
cb()
else
semaphore = arrReply.length
objReplies = {}
# } TODO What if the DB needs longer than two seconds to respond?...
setTimeout ->
if semaphore > 0
cb new Error('Timeout fetching ' + set)
, 2000
fCallback = (prop) ->
(err, data) ->
if err
err.addInfo = 'fetching single element: ' + prop
log.error 'DB', err
else
objReplies[prop] = data
if --semaphore == 0
cb null, objReplies
fSingle reply, fCallback(reply) for reply in arrReply
###
## Action Modules
###
###
Store a string representation of an action module in the DB.
@public storeActionModule ( *id, data* )
@param {String} id
@param {String} data
###
# FIXME can the data be an object?
exports.storeActionModule = (id, data) ->
db?.sadd 'action-modules', id, replyHandler 'storing action module key ' + id
db?.set 'action-module:' + id, data, replyHandler 'storing action module ' + id
###
Query the DB for an action module and pass it to the callback(err, obj) function.
@public getActionModule( *id, cb* )
@param {String} id
@param {function} cb
###
exports.getActionModule = (id, cb) ->
db?.get 'action-module:' + id, cb
###
Fetch all action modules and hand them to the callback(err, obj) function.
@public getActionModules( *cb* )
@param {function} cb
###
exports.getActionModules = (cb) ->
getSetRecords 'action-modules', exports.getActionModule, cb
###
Store a string representation of the authentication parameters for an action module.
@public storeActionAuth( *userId, moduleId, data* )
@param {String} userId
@param {String} moduleId
@param {String} data
###
exports.storeActionAuth = (userId, moduleId, data) ->
db?.set 'action-auth:' + userId + ':' + moduleId, encrypt(data),
replyHandler 'storing action auth ' + userId + ':' + moduleId
###
Query the DB for an action module authentication token associated to a user
and pass it to the callback(err, obj) function.
@public getActionAuth( *userId, moduleId, cb* )
@param {String} userId
@param {String} moduleId
@param {function} cb
###
exports.getActionAuth = (userId, moduleId, cb) ->
db?.get 'action-auth:' + userId + ':' + moduleId, (err, data) ->
cb err, decrypt data
###
## Event Modules
###
###
Store a string representation of an event module in the DB.
@public storeEventModule( *id, data* )
@param {String} id
@param {String} data
###
exports.storeEventModule = (id, data) ->
db?.sadd 'event-modules', id, replyHandler 'storing event module key ' + id
db?.set 'event-module:' + id, data, replyHandler 'storing event module ' + id
###
Query the DB for an event module and pass it to the callback(err, obj) function.
@public getEventModule( *id, cb* )
@param {String} id
@param {function} cb
###
exports.getEventModule = (id, cb) ->
db?.get 'event_module:' + id, cb
###
Fetch all event modules and pass them to the callback(err, obj) function.
@public getEventModules( *cb* )
@param {function} cb
###
exports.getEventModules = (cb) ->
getSetRecords 'event_modules', exports.getEventModule, cb
###
Store a string representation of he authentication parameters for an event module.
@public storeEventAuth( *userId, moduleId, data* )
@param {String} id
@param {String} data
###
exports.storeEventAuth = (userId, moduleId, data) ->
db?.set 'event-auth:' + userId + ':' + moduleId, encrypt(data),
replyHandler 'storing event auth ' + userId + ':' + moduleId
###
Query the DB for an action module authentication token, associated with a user.
@public getEventAuth( *id, cb* )
@param {String} id
@param {function} cb
###
exports.getEventAuth = (userId, moduleId, cb) ->
db?.get 'event-auth:' + userId + ':' + moduleId, (err, data) ->
cb err, decrypt data
###
## Rules
###
###
Store a string representation of a rule in the DB.
@public storeRule( *id, data* )
@param {String} id
@param {String} data
###
exports.storeRule = (id, data) ->
db?.sadd 'rules', id, replyHandler 'storing rule key ' + id
db?.set 'rule:' + id, data, replyHandler 'storing rule ' + id
###
Query the DB for a rule and pass it to the callback(err, obj) function.
@public getRule( *id, cb* )
@param {String} id
@param {function} cb
###
exports.getRule = (id, cb) ->
db?.get 'rule:' + id, cb
###
Fetch all rules from the database and pass them to the callback function.
@public getRules( *cb* )
@param {function} cb
###
exports.getRules = (cb) ->
getSetRecords 'rules', exports.getRule, cb
###
Store a user object (needs to be a flat structure).
@public storeUser( *objUser* )
@param {Object} objUser
###
exports.storeUser = (objUser) ->
if objUser and objUser.username and objUser.password
db?.sadd 'users', objUser.username, replyHandler 'storing user key ' + objUser.username
objUser.password = encrypt objUser.password
db?.hmset 'user:' + objUser.username, objUser, replyHandler 'storing user properties ' + objUser.username
else
log.error 'DB', new Error 'username or password was missing'
###
Associate a role with a user.
@public storeUserRole( *username, role* )
@param {String} username
@param {String} role
###
exports.storeUserRole = (username, role) ->
db?.sadd 'user-roles:' + username, role, replyHandler 'adding role ' + role + ' to user ' + username
db?.sadd 'role-users:' + role, username, replyHandler 'adding user ' + username + ' to role ' + role
###
Fetch all roles of a user and pass them to the callback(err, obj)
@public getUserRoles( *username* )
@param {String} username
###
exports.getUserRoles = (username) ->
db?.get 'user-roles:' + username, cb
###
Fetch all users of a role and pass them to the callback(err, obj)
@public getUserRoles( *role* )
@param {String} role
###
exports.getRoleUsers = (role) ->
db?.get 'role-users:' + role, cb
###
Checks the credentials and on success returns the user object to the callback(err, obj) function.
@public loginUser( *username, password, cb* )
@param {String} username
@param {String} password
@param {function} cb
###
# TODO verify and test whole function
exports.loginUser = (username, password, cb) ->
fCheck = (pw) ->
(err, obj) ->
if err
cb? err
else if obj and obj.password
if encrypt(obj.password) == pw
cb? null, obj
else cb? new Error 'Wrong credentials!'
else
cb? new Error 'Empty arguments!'
db?.get 'user:' + username, fCheck password
###
Shuts down the db link.
@public shutDown()
###
exports.shutDown = -> db?.quit()