Class: Twilio::Security::RequestValidator

Inherits:
Object
  • Object
show all
Defined in:
lib/twilio-ruby/security/request_validator.rb

Instance Method Summary collapse

Constructor Details

#initialize(auth_token = nil) ⇒ RequestValidator

Initialize a Request Validator. auth_token will either be grabbed from the global Twilio object or you can pass it in here.

Parameters:

  • auth_token (String) (defaults to: nil) —

    Your account auth token, used to sign requests

Raises:

  • (ArgumentError) 


11
12
13
14
 
# File 'lib/twilio-ruby/security/request_validator.rb', line 11

def initialize(auth_token = nil)
  @auth_token = auth_token || Twilio.auth_token
  raise ArgumentError, 'Auth token is required' if @auth_token.nil?
end

Instance Method Details

#build_hash_for(body) ⇒ String

Build a SHA256 hash for a body string

Parameters:

  • body (String) —

    String to hash

Returns:

  • (String) —

    A hex-encoded SHA256 of the body string



55
56
57
58
 
# File 'lib/twilio-ruby/security/request_validator.rb', line 55

def build_hash_for(body)
  hasher = OpenSSL::Digest.new('sha256')
  hasher.hexdigest(body)
end

#build_signature_for(url, params) ⇒ String

Build a SHA1-HMAC signature for a url and parameter hash

Parameters:

  • url (String) —

    The request url, including any query parameters

  • params (#join) —

    The POST parameters

Returns:

  • (String) —

    A base64 encoded SHA1-HMAC



67
68
69
70
71
 
# File 'lib/twilio-ruby/security/request_validator.rb', line 67

def build_signature_for(url, params)
  data = url + params.sort.join
  digest = OpenSSL::Digest.new('sha1')
  Base64.strict_encode64(OpenSSL::HMAC.digest(digest, @auth_token, data))
end

#validate(url, params, signature) ⇒ Boolean

Validates that after hashing a request with Twilio’s request-signing algorithm (www.twilio.com/docs/usage/security#validating-requests), the hash matches the signature parameter

Parameters:

  • url (String) —

    The url sent to your server, including any query parameters

  • params (String, Hash, #to_unsafe_h) —

    In most cases, this is the POST parameters as a hash. If you received a bodySHA256 parameter in the query string, this parameter can instead be the POST body as a string to validate JSON or other text-based payloads that aren’t x-www-form-urlencoded.

  • signature (String) —

    The expected signature, from the X-Twilio-Signature header of the request

Returns:

  • (Boolean) —

    whether or not the computed signature matches the signature parameter



27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
 
# File 'lib/twilio-ruby/security/request_validator.rb', line 27

def validate(url, params, signature)
  parsed_url = URI(url)
  url_with_port = add_port(parsed_url)
  url_without_port = remove_port(parsed_url)

  valid_body = true # default succeed, since body not always provided
  params_hash = body_or_hash(params)
  unless params_hash.is_a? Enumerable
    body_hash = URI.decode_www_form(parsed_url.query || '').to_h['bodySHA256']
    params_hash = build_hash_for(params)
    valid_body = !(params_hash.nil? || body_hash.nil?) && secure_compare(params_hash, body_hash)
    params_hash = {}
  end

  # Check signature of the url with and without port numbers
  # since signature generation on the back end is inconsistent
  valid_signature_with_port = secure_compare(build_signature_for(url_with_port, params_hash), signature)
  valid_signature_without_port = secure_compare(build_signature_for(url_without_port, params_hash), signature)

  valid_body && (valid_signature_with_port || valid_signature_without_port)
end