Class: SignedJson::Signer

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

Instance Method Summary collapse

Constructor Details

#initialize(secret, digest = 'SHA1') ⇒ Signer

Returns a new instance of Signer.



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

def initialize(secret, digest = 'SHA1')
  @secret = secret
  @digest = digest
end

Instance Method Details

#decode(input) ⇒ Object

Raises:



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# File 'lib/signed_json.rb', line 17

def decode(input)
  digest, data = decode_digest_and_data(input)
  raise SignatureError unless digest === digest_for(data)
  data
end

#digest_for(input) ⇒ Object

Generates an HMAC digest for the JSON representation of the given input. JSON generation must be consistent across platforms. e.g. in Python, specify separators=(‘,’,‘:’) to eliminate whitespace.



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# File 'lib/signed_json.rb', line 26

def digest_for(input)
  require 'openssl' unless defined?(OpenSSL) # from ActiveSupport::MessageVerifier
  digest = OpenSSL::Digest.const_get(@digest).new
  OpenSSL::HMAC.hexdigest(digest, @secret, signature_input(input))
end

#encode(input) ⇒ Object 



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# File 'lib/signed_json.rb', line 12

def encode(input)
  data_to_encode = [digest_for(input), input]
  JSON.generate(data_to_encode)
end