1 files changed, 188 insertions, 0 deletions
diff --git a/spec/lib/gitlab/mail_room/authenticator_spec.rb b/spec/lib/gitlab/mail_room/authenticator_spec.rb
new file mode 100644
index 00000000000..44120902661
--- /dev/null
+++ b/spec/lib/gitlab/mail_room/authenticator_spec.rb
@@ -0,0 +1,188 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::MailRoom::Authenticator do
+  let(:yml_config) do
+    {
+      enabled: true,
+      address: 'address@example.com'
+    }
+  end
+
+  let(:incoming_email_secret_path) { '/path/to/incoming_email_secret' }
+  let(:incoming_email_config) { yml_config.merge(secret_file: incoming_email_secret_path) }
+
+  let(:service_desk_email_secret_path) { '/path/to/service_desk_email_secret' }
+  let(:service_desk_email_config) { yml_config.merge(secret_file: service_desk_email_secret_path) }
+
+  let(:configs) do
+    {
+      incoming_email: incoming_email_config,
+      service_desk_email: service_desk_email_config
+    }
+  end
+
+  before do
+    allow(Gitlab::MailRoom).to receive(:enabled_configs).and_return(configs)
+
+    described_class.clear_memoization(:jwt_secret_incoming_email)
+    described_class.clear_memoization(:jwt_secret_service_desk_email)
+  end
+
+  after do
+    described_class.clear_memoization(:jwt_secret_incoming_email)
+    described_class.clear_memoization(:jwt_secret_service_desk_email)
+  end
+
+  around do |example|
+    freeze_time do
+      example.run
+    end
+  end
+
+  describe '#verify_api_request' do
+    let(:incoming_email_secret) { SecureRandom.hex(16) }
+    let(:service_desk_email_secret) { SecureRandom.hex(16) }
+    let(:payload) { { iss: described_class::INTERNAL_API_REQUEST_JWT_ISSUER, iat: (Time.current - 5.minutes + 1.second).to_i } }
+
+    before do
+      allow(described_class).to receive(:secret).with(:incoming_email).and_return(incoming_email_secret)
+      allow(described_class).to receive(:secret).with(:service_desk_email).and_return(service_desk_email_secret)
+    end
+
+    context 'verify a valid token' do
+      it 'returns the decoded payload' do
+        encoded_token = JWT.encode(payload, incoming_email_secret, 'HS256')
+        headers = { described_class::INTERNAL_API_REQUEST_HEADER => encoded_token }
+
+        expect(described_class.verify_api_request(headers, 'incoming_email')[0]).to match a_hash_including(
+          "iss" => "gitlab-mailroom",
+          "iat" => be_a(Integer)
+        )
+
+        encoded_token = JWT.encode(payload, service_desk_email_secret, 'HS256')
+        headers = { described_class::INTERNAL_API_REQUEST_HEADER => encoded_token }
+
+        expect(described_class.verify_api_request(headers, 'service_desk_email')[0]).to match a_hash_including(
+          "iss" => "gitlab-mailroom",
+          "iat" => be_a(Integer)
+        )
+      end
+    end
+
+    context 'verify an invalid token' do
+      it 'returns false' do
+        encoded_token = JWT.encode(payload, 'wrong secret', 'HS256')
+        headers = { described_class::INTERNAL_API_REQUEST_HEADER => encoded_token }
+
+        expect(described_class.verify_api_request(headers, 'incoming_email')).to eq(false)
+      end
+    end
+
+    context 'verify a valid token but wrong mailbox type' do
+      it 'returns false' do
+        encoded_token = JWT.encode(payload, incoming_email_secret, 'HS256')
+        headers = { described_class::INTERNAL_API_REQUEST_HEADER => encoded_token }
+
+        expect(described_class.verify_api_request(headers, 'service_desk_email')).to eq(false)
+      end
+    end
+
+    context 'verify a valid token but wrong issuer' do
+      let(:payload) { { iss: 'invalid_issuer' } }
+
+      it 'returns false' do
+        encoded_token = JWT.encode(payload, incoming_email_secret, 'HS256')
+        headers = { described_class::INTERNAL_API_REQUEST_HEADER => encoded_token }
+
+        expect(described_class.verify_api_request(headers, 'incoming_email')).to eq(false)
+      end
+    end
+
+    context 'verify a valid token but expired' do
+      let(:payload) { { iss: described_class::INTERNAL_API_REQUEST_JWT_ISSUER, iat: (Time.current - 5.minutes - 1.second).to_i } }
+
+      it 'returns false' do
+        encoded_token = JWT.encode(payload, incoming_email_secret, 'HS256')
+        headers = { described_class::INTERNAL_API_REQUEST_HEADER => encoded_token }
+
+        expect(described_class.verify_api_request(headers, 'incoming_email')).to eq(false)
+      end
+    end
+
+    context 'verify a valid token but wrong header field' do
+      it 'returns false' do
+        encoded_token = JWT.encode(payload, incoming_email_secret, 'HS256')
+        headers = { 'a-wrong-header' => encoded_token }
+
+        expect(described_class.verify_api_request(headers, 'incoming_email')).to eq(false)
+      end
+    end
+
+    context 'verify headers for a disabled mailbox type' do
+      let(:configs) { { service_desk_email: service_desk_email_config } }
+
+      it 'returns false' do
+        encoded_token = JWT.encode(payload, incoming_email_secret, 'HS256')
+        headers = { described_class::INTERNAL_API_REQUEST_HEADER => encoded_token }
+
+        expect(described_class.verify_api_request(headers, 'incoming_email')).to eq(false)
+      end
+    end
+
+    context 'verify headers for a non-existing mailbox type' do
+      it 'returns false' do
+        headers = { described_class::INTERNAL_API_REQUEST_HEADER => 'something' }
+
+        expect(described_class.verify_api_request(headers, 'invalid_mailbox_type')).to eq(false)
+      end
+    end
+  end
+
+  describe '#secret' do
+    let(:incoming_email_secret) { SecureRandom.hex(16) }
+    let(:service_desk_email_secret) { SecureRandom.hex(16) }
+
+    context 'the secret is valid' do
+      before do
+        allow(described_class).to receive(:read_secret).with(incoming_email_secret_path).and_return(incoming_email_secret).once
+        allow(described_class).to receive(:read_secret).with(service_desk_email_secret_path).and_return(service_desk_email_secret).once
+      end
+
+      it 'returns the memorized secret from a file' do
+        expect(described_class.secret(:incoming_email)).to eql(incoming_email_secret)
+        # The second call does not trigger secret read again
+        expect(described_class.secret(:incoming_email)).to eql(incoming_email_secret)
+        expect(described_class).to have_received(:read_secret).with(incoming_email_secret_path).once
+
+        expect(described_class.secret(:service_desk_email)).to eql(service_desk_email_secret)
+        # The second call does not trigger secret read again
+        expect(described_class.secret(:service_desk_email)).to eql(service_desk_email_secret)
+        expect(described_class).to have_received(:read_secret).with(service_desk_email_secret_path).once
+      end
+    end
+
+    context 'the secret file is not configured' do
+      let(:incoming_email_config) { yml_config }
+
+      it 'raises a SecretConfigurationError exception' do
+        expect do
+          described_class.secret(:incoming_email)
+        end.to raise_error(described_class::SecretConfigurationError, "incoming_email's secret_file configuration is missing")
+      end
+    end
+
+    context 'the secret file not found' do
+      before do
+        allow(described_class).to receive(:read_secret).with(incoming_email_secret_path).and_raise(Errno::ENOENT)
+      end
+
+      it 'raises a SecretConfigurationError exception' do
+        expect do
+          described_class.secret(:incoming_email)
+        end.to raise_error(described_class::SecretConfigurationError, "Fail to read incoming_email's secret: No such file or directory")
+      end
+    end
+  end
+end