Splits the JWTHeader creds into its own class

This commit is contained in:
Tim Emiola 2015-03-17 18:26:40 -07:00
parent e3e33e2c38
commit 53ec6fce3b
2 changed files with 224 additions and 77 deletions

View File

@ -36,7 +36,8 @@ module Google
# Module Auth provides classes that provide Google-specific authorization # Module Auth provides classes that provide Google-specific authorization
# used to access Google APIs. # used to access Google APIs.
module Auth module Auth
# Authenticates requests using Google's Service Account credentials. # Authenticates requests using Google's Service Account credentials via an
# OAuth access token.
# #
# This class allows authorizing requests for service accounts directly # This class allows authorizing requests for service accounts directly
# from credentials from a json key file downloaded from the developer # from credentials from a json key file downloaded from the developer
@ -44,8 +45,6 @@ module Google
# #
# cf [Application Default Credentials](http://goo.gl/mkAHpZ) # cf [Application Default Credentials](http://goo.gl/mkAHpZ)
class ServiceAccountCredentials < Signet::OAuth2::Client class ServiceAccountCredentials < Signet::OAuth2::Client
JWT_AUD_URI_KEY = :jwt_aud_uri
AUTH_METADATA_KEY = Signet::OAuth2::AUTH_METADATA_KEY
TOKEN_CRED_URI = 'https://www.googleapis.com/oauth2/v3/token' TOKEN_CRED_URI = 'https://www.googleapis.com/oauth2/v3/token'
extend CredentialsLoader extend CredentialsLoader
@ -70,33 +69,94 @@ module Google
issuer: client_email, issuer: client_email,
signing_key: OpenSSL::PKey::RSA.new(private_key)) signing_key: OpenSSL::PKey::RSA.new(private_key))
end end
end
# Extends the superclass behaviour to construct a jwt token if the # Authenticates requests using Google's Service Account credentials via
# google jwt uri key is present in the input hash. # JWT Header.
# #
# The jwt is used as the authentication token. # This class allows authorizing requests for service accounts directly
# from credentials from a json key file downloaded from the developer
# console (via 'Generate new Json Key'). It is not part of any OAuth2
# flow, rather it creates a JWT and sends that as a credential.
#
# cf [Application Default Credentials](http://goo.gl/mkAHpZ)
class ServiceAccountJwtHeaderCredentials
JWT_AUD_URI_KEY = :jwt_aud_uri
AUTH_METADATA_KEY = Signet::OAuth2::AUTH_METADATA_KEY
TOKEN_CRED_URI = 'https://www.googleapis.com/oauth2/v3/token'
SIGNING_ALGORITHM = 'RS256'
EXPIRY = 60
extend CredentialsLoader
# make_creds proxies the construction of a credentials instance
#
# make_creds is used by the methods in CredentialsLoader.
#
# By default, it calls #new with 2 args, the second one being an
# optional scope. Here's the constructor only has one param, so
# we modify make_creds to reflect this.
def self.make_creds(*args)
new(args[0])
end
# Reads the private key and client email fields from the service account
# JSON key.
def self.read_json_key(json_key_io)
json_key = MultiJson.load(json_key_io.read)
fail 'missing client_email' unless json_key.key?('client_email')
fail 'missing private_key' unless json_key.key?('private_key')
[json_key['private_key'], json_key['client_email']]
end
# Initializes a ServiceAccountJwtHeaderCredentials.
#
# @param json_key_io [IO] an IO from which the JSON key can be read
def initialize(json_key_io)
private_key, client_email = self.class.read_json_key(json_key_io)
@private_key = private_key
@issuer = client_email
@signing_key = OpenSSL::PKey::RSA.new(private_key)
end
# Construct a jwt token if the WT_AUD_URI key is present in the input
# hash.
#
# The jwt token is used as the value of a 'Bearer '.
def apply!(a_hash, opts = {}) def apply!(a_hash, opts = {})
jwt_aud_uri = a_hash.delete(JWT_AUD_URI_KEY) jwt_aud_uri = a_hash.delete(JWT_AUD_URI_KEY)
unless jwt_aud_uri.nil? return a_hash if jwt_aud_uri.nil?
jwt_token = new_jwt_token(jwt_aud_uri, opts) jwt_token = new_jwt_token(jwt_aud_uri, opts)
a_hash[AUTH_METADATA_KEY] = "Bearer #{jwt_token}" a_hash[AUTH_METADATA_KEY] = "Bearer #{jwt_token}"
return a_hash a_hash
end end
super
# Returns a clone of a_hash updated with the authoriation header
def apply(a_hash, opts = {})
a_copy = a_hash.clone
apply!(a_copy, opts)
a_copy
end end
# Returns a reference to the #apply method, suitable for passing as
# a closure
def updater_proc
lambda(&method(:apply))
end
protected
# Creates a jwt uri token. # Creates a jwt uri token.
def new_jwt_token(jwt_aud_uri, options = {}) def new_jwt_token(jwt_aud_uri, options = {})
now = Time.new now = Time.new
skew = options[:skew] || 60 skew = options[:skew] || 60
assertion = { assertion = {
'iss' => issuer, 'iss' => @issuer,
'sub' => issuer, 'sub' => @issuer,
'aud' => jwt_aud_uri, 'aud' => jwt_aud_uri,
'exp' => (now + expiry).to_i, 'exp' => (now + EXPIRY).to_i,
'iat' => (now - skew).to_i 'iat' => (now - skew).to_i
} }
JWT.encode(assertion, signing_key, signing_algorithm) JWT.encode(assertion, @signing_key, SIGNING_ALGORITHM)
end end
end end
end end

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@ -80,67 +80,6 @@ describe Google::Auth::ServiceAccountCredentials do
it_behaves_like 'apply/apply! are OK' it_behaves_like 'apply/apply! are OK'
context 'when jwt_aud_uri is present' do
WANTED_AUTH_KEY = ServiceAccountCredentials::AUTH_METADATA_KEY
JWT_AUD_URI_KEY = ServiceAccountCredentials::JWT_AUD_URI_KEY
let(:test_uri) { 'https://www.googleapis.com/myservice' }
let(:auth_prefix) { 'Bearer ' }
def expect_is_encoded_jwt(hdr)
expect(hdr).to_not be_nil
expect(hdr.start_with?(auth_prefix)).to be true
authorization = hdr[auth_prefix.length..-1]
payload, _ = JWT.decode(authorization, @key.public_key)
expect(payload['aud']).to eq(test_uri)
expect(payload['iss']).to eq(client_email)
end
describe '#apply!' do
it 'should update the target hash with a jwt token' do
md = { foo: 'bar' }
md[JWT_AUD_URI_KEY] = test_uri
@client.apply!(md)
auth_header = md[WANTED_AUTH_KEY]
expect_is_encoded_jwt(auth_header)
expect(md[JWT_AUD_URI_KEY]).to be_nil
end
end
describe 'updater_proc' do
it 'should provide a proc that updates a hash with a jwt token' do
md = { foo: 'bar' }
md[JWT_AUD_URI_KEY] = test_uri
the_proc = @client.updater_proc
got = the_proc.call(md)
auth_header = got[WANTED_AUTH_KEY]
expect_is_encoded_jwt(auth_header)
expect(got[JWT_AUD_URI_KEY]).to be_nil
expect(md[JWT_AUD_URI_KEY]).to_not be_nil
end
end
describe '#apply' do
it 'should not update the original hash with a jwt token' do
md = { foo: 'bar' }
md[JWT_AUD_URI_KEY] = test_uri
the_proc = @client.updater_proc
got = the_proc.call(md)
auth_header = md[WANTED_AUTH_KEY]
expect(auth_header).to be_nil
expect(got[JWT_AUD_URI_KEY]).to be_nil
expect(md[JWT_AUD_URI_KEY]).to_not be_nil
end
it 'should add a jwt token to the returned hash' do
md = { foo: 'bar' }
md[JWT_AUD_URI_KEY] = test_uri
got = @client.apply(md)
auth_header = got[WANTED_AUTH_KEY]
expect_is_encoded_jwt(auth_header)
end
end
end
describe '#from_env' do describe '#from_env' do
before(:example) do before(:example) do
@var_name = CredentialsLoader::ENV_VAR @var_name = CredentialsLoader::ENV_VAR
@ -207,3 +146,151 @@ describe Google::Auth::ServiceAccountCredentials do
end end
end end
end end
describe Google::Auth::ServiceAccountJwtHeaderCredentials do
CredentialsLoader = Google::Auth::CredentialsLoader
ServiceAccountJwtHeaderCredentials =
Google::Auth::ServiceAccountJwtHeaderCredentials
let(:client_email) { 'app@developer.gserviceaccount.com' }
let(:clz) { Google::Auth::ServiceAccountJwtHeaderCredentials }
before(:example) do
@key = OpenSSL::PKey::RSA.new(2048)
@client = clz.new(StringIO.new(cred_json_text))
end
def cred_json_text
cred_json = {
private_key_id: 'a_private_key_id',
private_key: @key.to_pem,
client_email: client_email,
client_id: 'app.apps.googleusercontent.com',
type: 'service_account'
}
MultiJson.dump(cred_json)
end
context 'when jwt_aud_uri is present' do
WANTED_AUTH_KEY = ServiceAccountJwtHeaderCredentials::AUTH_METADATA_KEY
JWT_AUD_URI_KEY = ServiceAccountJwtHeaderCredentials::JWT_AUD_URI_KEY
let(:test_uri) { 'https://www.googleapis.com/myservice' }
let(:auth_prefix) { 'Bearer ' }
def expect_is_encoded_jwt(hdr)
expect(hdr).to_not be_nil
expect(hdr.start_with?(auth_prefix)).to be true
authorization = hdr[auth_prefix.length..-1]
payload, _ = JWT.decode(authorization, @key.public_key)
expect(payload['aud']).to eq(test_uri)
expect(payload['iss']).to eq(client_email)
end
describe '#apply!' do
it 'should update the target hash with a jwt token' do
md = { foo: 'bar' }
md[JWT_AUD_URI_KEY] = test_uri
@client.apply!(md)
auth_header = md[WANTED_AUTH_KEY]
expect_is_encoded_jwt(auth_header)
expect(md[JWT_AUD_URI_KEY]).to be_nil
end
end
describe 'updater_proc' do
it 'should provide a proc that updates a hash with a jwt token' do
md = { foo: 'bar' }
md[JWT_AUD_URI_KEY] = test_uri
the_proc = @client.updater_proc
got = the_proc.call(md)
auth_header = got[WANTED_AUTH_KEY]
expect_is_encoded_jwt(auth_header)
expect(got[JWT_AUD_URI_KEY]).to be_nil
expect(md[JWT_AUD_URI_KEY]).to_not be_nil
end
end
describe '#apply' do
it 'should not update the original hash with a jwt token' do
md = { foo: 'bar' }
md[JWT_AUD_URI_KEY] = test_uri
the_proc = @client.updater_proc
got = the_proc.call(md)
auth_header = md[WANTED_AUTH_KEY]
expect(auth_header).to be_nil
expect(got[JWT_AUD_URI_KEY]).to be_nil
expect(md[JWT_AUD_URI_KEY]).to_not be_nil
end
it 'should add a jwt token to the returned hash' do
md = { foo: 'bar' }
md[JWT_AUD_URI_KEY] = test_uri
got = @client.apply(md)
auth_header = got[WANTED_AUTH_KEY]
expect_is_encoded_jwt(auth_header)
end
end
end
describe '#from_env' do
before(:example) do
@var_name = CredentialsLoader::ENV_VAR
@orig = ENV[@var_name]
end
after(:example) do
ENV[@var_name] = @orig unless @orig.nil?
end
it 'returns nil if the GOOGLE_APPLICATION_CREDENTIALS is unset' do
ENV.delete(@var_name) unless ENV[@var_name].nil?
expect(clz.from_env).to be_nil
end
it 'fails if the GOOGLE_APPLICATION_CREDENTIALS path does not exist' do
ENV.delete(@var_name) unless ENV[@var_name].nil?
expect(clz.from_env).to be_nil
Dir.mktmpdir do |dir|
key_path = File.join(dir, 'does-not-exist')
ENV[@var_name] = key_path
expect { clz.from_env }.to raise_error
end
end
it 'succeeds when the GOOGLE_APPLICATION_CREDENTIALS file is valid' do
Dir.mktmpdir do |dir|
key_path = File.join(dir, 'my_cert_file')
FileUtils.mkdir_p(File.dirname(key_path))
File.write(key_path, cred_json_text)
ENV[@var_name] = key_path
expect(clz.from_env).to_not be_nil
end
end
end
describe '#from_well_known_path' do
before(:example) do
@home = ENV['HOME']
@known_path = CredentialsLoader::WELL_KNOWN_PATH
end
after(:example) do
ENV['HOME'] = @home unless @home == ENV['HOME']
end
it 'is nil if no file exists' do
ENV['HOME'] = File.dirname(__FILE__)
expect(clz.from_well_known_path).to be_nil
end
it 'successfully loads the file when it is present' do
Dir.mktmpdir do |dir|
key_path = File.join(dir, '.config', @known_path)
FileUtils.mkdir_p(File.dirname(key_path))
File.write(key_path, cred_json_text)
ENV['HOME'] = dir
expect(clz.from_well_known_path).to_not be_nil
end
end
end
end