125 lines
4.2 KiB
Ruby
125 lines
4.2 KiB
Ruby
# Copyright 2010 Google Inc.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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require 'jwt'
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require 'signet/oauth_2/client'
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module Google
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class APIClient
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##
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# Generates access tokens using the JWT assertion profile. Requires a
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# service account & access to the private key.
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#
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# @example
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#
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# client = Google::APIClient.new
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# key = Google::APIClient::PKCS12.load_key('client.p12', 'notasecret')
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# service_account = Google::APIClient::JWTAsserter(
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# '123456-abcdef@developer.gserviceaccount.com',
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# 'https://www.googleapis.com/auth/prediction',
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# key)
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# client.authorization = service_account.authorize
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# client.execute(...)
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#
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# @see https://developers.google.com/accounts/docs/OAuth2ServiceAccount
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class JWTAsserter
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# @return [String] ID/email of the issuing party
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attr_accessor :issuer
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# @return [Fixnum] How long, in seconds, the assertion is valid for
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attr_accessor :expiry
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# @return [Fixnum] Seconds to expand the issued at/expiry window to account for clock skew
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attr_accessor :skew
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# @return [String] Scopes to authorize
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attr_reader :scope
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# @return [OpenSSL::PKey] key for signing assertions
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attr_writer :key
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##
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# Initializes the asserter for a service account.
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#
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# @param [String] issuer
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# Name/ID of the client issuing the assertion
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# @param [String, Array] scope
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# Scopes to authorize. May be a space delimited string or array of strings
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# @param [OpenSSL::PKey] key
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# RSA private key for signing assertions
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def initialize(issuer, scope, key)
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self.issuer = issuer
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self.scope = scope
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self.expiry = 60 # 1 min default
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self.skew = 60
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self.key = key
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end
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##
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# Set the scopes to authorize
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#
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# @param [String, Array] new_scope
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# Scopes to authorize. May be a space delimited string or array of strings
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def scope=(new_scope)
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case new_scope
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when Array
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@scope = new_scope.join(' ')
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when String
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@scope = new_scope
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when nil
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@scope = ''
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else
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raise TypeError, "Expected Array or String, got #{new_scope.class}"
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end
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end
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##
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# Builds & signs the assertion.
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#
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# @param [String] person
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# Email address of a user, if requesting a token to act on their behalf
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# @return [String] Encoded JWT
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def to_jwt(person=nil)
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now = Time.new
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assertion = {
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"iss" => @issuer,
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"scope" => self.scope,
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"aud" => "https://accounts.google.com/o/oauth2/token",
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"exp" => (now + expiry).to_i,
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"iat" => (now - skew).to_i
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}
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assertion['prn'] = person unless person.nil?
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return JWT.encode(assertion, @key, "RS256")
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end
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##
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# Request a new access token.
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#
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# @param [String] person
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# Email address of a user, if requesting a token to act on their behalf
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# @param [Hash] options
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# Pass through to Signet::OAuth2::Client.fetch_access_token
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# @return [Signet::OAuth2::Client] Access token
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#
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# @see Signet::OAuth2::Client.fetch_access_token
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def authorize(person = nil, options={})
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assertion = self.to_jwt(person)
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authorization = Signet::OAuth2::Client.new(
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:token_credential_uri => 'https://accounts.google.com/o/oauth2/token'
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)
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authorization.grant_type = 'urn:ietf:params:oauth:grant-type:jwt-bearer'
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authorization.extension_parameters = { :assertion => assertion }
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authorization.fetch_access_token!(options)
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return authorization
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end
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end
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end
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end
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