1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
# Guard API with OAuth 2.0 Access Token
require 'rack/oauth2'
module APIGuard
extend ActiveSupport::Concern
included do |base|
# OAuth2 Resource Server Authentication
use Rack::OAuth2::Server::Resource::Bearer, 'The API' do |request|
# The authenticator only fetches the raw token string
# Must yield access token to store it in the env
request.access_token
end
helpers HelperMethods
install_error_responders(base)
end
# Helper Methods for Grape Endpoint
module HelperMethods
# Invokes the doorkeeper guard.
#
# If token is presented and valid, then it sets @current_user.
#
# If the token does not have sufficient scopes to cover the requred scopes,
# then it raises InsufficientScopeError.
#
# If the token is expired, then it raises ExpiredError.
#
# If the token is revoked, then it raises RevokedError.
#
# If the token is not found (nil), then it raises TokenNotFoundError.
#
# Arguments:
#
# scopes: (optional) scopes required for this guard.
# Defaults to empty array.
#
def doorkeeper_guard!(scopes: [])
if (access_token = find_access_token).nil?
raise TokenNotFoundError
else
case validate_access_token(access_token, scopes)
when Oauth2::AccessTokenValidationService::INSUFFICIENT_SCOPE
raise InsufficientScopeError.new(scopes)
when Oauth2::AccessTokenValidationService::EXPIRED
raise ExpiredError
when Oauth2::AccessTokenValidationService::REVOKED
raise RevokedError
when Oauth2::AccessTokenValidationService::VALID
@current_user = User.find(access_token.resource_owner_id)
end
end
end
def doorkeeper_guard(scopes: [])
if access_token = find_access_token
case validate_access_token(access_token, scopes)
when Oauth2::AccessTokenValidationService::INSUFFICIENT_SCOPE
raise InsufficientScopeError.new(scopes)
when Oauth2::AccessTokenValidationService::EXPIRED
raise ExpiredError
when Oauth2::AccessTokenValidationService::REVOKED
raise RevokedError
when Oauth2::AccessTokenValidationService::VALID
@current_user = User.find(access_token.resource_owner_id)
end
end
end
def current_user
@current_user
end
private
def find_access_token
@access_token ||= Doorkeeper.authenticate(doorkeeper_request, Doorkeeper.configuration.access_token_methods)
end
def doorkeeper_request
@doorkeeper_request ||= ActionDispatch::Request.new(env)
end
def validate_access_token(access_token, scopes)
Oauth2::AccessTokenValidationService.validate(access_token, scopes: scopes)
end
end
module ClassMethods
# Installs the doorkeeper guard on the whole Grape API endpoint.
#
# Arguments:
#
# scopes: (optional) scopes required for this guard.
# Defaults to empty array.
#
def guard_all!(scopes: [])
before do
guard! scopes: scopes
end
end
private
def install_error_responders(base)
error_classes = [ MissingTokenError, TokenNotFoundError,
ExpiredError, RevokedError, InsufficientScopeError]
base.send :rescue_from, *error_classes, oauth2_bearer_token_error_handler
end
def oauth2_bearer_token_error_handler
Proc.new do |e|
response =
case e
when MissingTokenError
Rack::OAuth2::Server::Resource::Bearer::Unauthorized.new
when TokenNotFoundError
Rack::OAuth2::Server::Resource::Bearer::Unauthorized.new(
:invalid_token,
"Bad Access Token.")
when ExpiredError
Rack::OAuth2::Server::Resource::Bearer::Unauthorized.new(
:invalid_token,
"Token is expired. You can either do re-authorization or token refresh.")
when RevokedError
Rack::OAuth2::Server::Resource::Bearer::Unauthorized.new(
:invalid_token,
"Token was revoked. You have to re-authorize from the user.")
when InsufficientScopeError
# FIXME: ForbiddenError (inherited from Bearer::Forbidden of Rack::Oauth2)
# does not include WWW-Authenticate header, which breaks the standard.
Rack::OAuth2::Server::Resource::Bearer::Forbidden.new(
:insufficient_scope,
Rack::OAuth2::Server::Resource::ErrorMethods::DEFAULT_DESCRIPTION[:insufficient_scope],
{ scope: e.scopes })
end
response.finish
end
end
end
#
# Exceptions
#
class MissingTokenError < StandardError; end
class TokenNotFoundError < StandardError; end
class ExpiredError < StandardError; end
class RevokedError < StandardError; end
class InsufficientScopeError < StandardError
attr_reader :scopes
def initialize(scopes)
@scopes = scopes
end
end
end
|
