Class: EzToken

Inherits:
Object
  • Object
show all
Defined in:
lib/ez_token.rb

Overview

This class helps to create and decode SHA1 encoded tokens utf-8 strings are supported:

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(sec) ⇒ EzToken

pass your secret



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# File 'lib/ez_token.rb', line 10

def initialize(sec)
  @secret = sec
end

Instance Attribute Details

#secret ⇒ Object (readonly)

Returns the value of attribute secret.



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# File 'lib/ez_token.rb', line 7

def secret
  @secret
end

Instance Method Details

#generate(params, now = Time.now.to_i) ⇒ Object

Return a token representing the params + the timestamp + a digest the digest is a generate a 40 hex-character (640bit) SHA1 encoding of the params + timestamp + secret params can be a String, an Array (each item in the array is joined with a &) or a Hash (each item in the hash is of the form key=value and each of those are joined with &). We url encode the array items, the hash values and the String value. Array items and Hash values are turned into their String representation. If params is a Hash, the keys cannot contain a & or =. Values that are nil will be replaced by the empty string upon decoding/verify. For arrays, nil items in an array will be replaced by the string representation of nil which is ”.



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# File 'lib/ez_token.rb', line 23

def generate(params, now = Time.now.to_i)
  # Note: for oddly utf-8 encoded strings empty? will fail, we circumvent this by testing the length first
  raise 'EzToken.generate: Params cannot be empty' if params.nil? || params.empty?

  # order hash by keys
  return get_hash_token(params, now) if params.class == Hash
  return get_array_token(params, now) if params.class == Array
  return get_string_token(params, now) if params.class == String
  raise "EzToken.generate: Params of class #{params.class} is invalid. Must be String, Hash or Array"
end

#verify(token, interval = nil, allow_expired = false) ⇒ Object

Decode token that was originally encoded in the form <payload>&ts=<integer timestamp>&SECRET where payload can be a string separated by &. Take the <payload> and turn into a String, Hash or Array depending on its format:

if there are no & and no '=' its a URL encoded String
if there are just & its an Array (separated by &)
otherwise it is a hash of the form key=value&key=value...

If interval is non-nil it represents the length in seconds for the max age of this token We return false if the decoding didnt work, we return “expired” if the interval is non-nil and

the token has expired

Otherwise we return the original payload encoded in the token.



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# File 'lib/ez_token.rb', line 44

def verify(token, interval = nil, allow_expired = false)
  payload, ts = decode_token_into_payload(token)
  return false if payload == false

  is_expired = !interval.nil? && ts + interval < Time.now.to_i
  return 'expired' if allow_expired && is_expired
  return false if is_expired

  return TypeCaster.new(payload).uri_decode if payload !~ /[&=]/ # a (url encoded) string
  return decode_array(payload) if payload !~ /=/ # its an Array - it has a & in it
  decode_hash(payload)
end

#verify!(token, interval = nil) ⇒ Object 



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# File 'lib/ez_token.rb', line 57

def verify!(token, interval = nil)
  params = verify(token, interval, true)
  raise 'EzToken.verify!: Token is invalid' if params == false
  raise 'EzToken.verify!: Token has expired' if params == 'expired'
  params
end

#verify?(token, interval = nil) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ez_token.rb', line 64

def verify?(token, interval = nil)
  params = verify(token, interval, true)
  return false if params == false || params == 'expired'
  true
end