50 lines
1.4 KiB
Ruby
50 lines
1.4 KiB
Ruby
|
# frozen_string_literal: true
|
||
|
|
|
||
|
|
require 'json'
|
||
|
|
|
||
|
|
# JWT::Decode module
|
||
|
|
module JWT
|
||
|
|
# Decoding logic for JWT
|
||
|
|
class Decode
|
||
|
|
attr_reader :header, :payload, :signature
|
||
|
|
|
||
|
|
def self.base64url_decode(str)
|
||
|
|
str += '=' * (4 - str.length.modulo(4))
|
||
|
|
Base64.decode64(str.tr('-_', '+/'))
|
||
|
|
end
|
||
|
|
|
||
|
|
def initialize(jwt, verify)
|
||
|
|
@jwt = jwt
|
||
|
|
@verify = verify
|
||
|
|
@header = ''
|
||
|
|
@payload = ''
|
||
|
|
@signature = ''
|
||
|
|
end
|
||
|
|
|
||
|
|
def decode_segments
|
||
|
|
header_segment, payload_segment, crypto_segment = raw_segments
|
||
|
|
@header, @payload = decode_header_and_payload(header_segment, payload_segment)
|
||
|
|
@signature = Decode.base64url_decode(crypto_segment.to_s) if @verify
|
||
|
|
signing_input = [header_segment, payload_segment].join('.')
|
||
|
|
[@header, @payload, @signature, signing_input]
|
||
|
|
end
|
||
|
|
|
||
|
|
private
|
||
|
|
|
||
|
|
def raw_segments
|
||
|
|
segments = @jwt.split('.')
|
||
|
|
required_num_segments = @verify ? [3] : [2, 3]
|
||
|
|
raise(JWT::DecodeError, 'Not enough or too many segments') unless required_num_segments.include? segments.length
|
||
|
|
segments
|
||
|
|
end
|
||
|
|
|
||
|
|
def decode_header_and_payload(header_segment, payload_segment)
|
||
|
|
header = JSON.parse(Decode.base64url_decode(header_segment))
|
||
|
|
payload = JSON.parse(Decode.base64url_decode(payload_segment))
|
||
|
|
[header, payload]
|
||
|
|
rescue JSON::ParserError
|
||
|
|
raise JWT::DecodeError, 'Invalid segment encoding'
|
||
|
|
end
|
||
|
|
end
|
||
|
|
end
|