Implement resource owner credentials (#7424)

* Implement resource owner credentials

* Fix link name

* get_access_token_using_*

* remove headers from response

* Address comments

* Display timeout value in exception

spec/std/http/spec_helper.cr

@@ -0,0 +1,46 @@
+require "spec"
+
+private def wait_for(timeout = 5.seconds)
+  now = Time.monotonic
+
+  until yield
+    Fiber.yield
+
+    if (Time.monotonic - now) > timeout
+      raise "server failed to start within #{timeout}"
+    end
+  end
+end
+
+# Helper method which runs *server*
+# 1. Spawns `server.listen` in a new fiber.
+# 2. Waits until `server.listening?`.
+# 3. Yields to the given block.
+# 4. Ensures the server is closed.
+# 5. After returning from the block, it waits for the server to gracefully
+#    shut down before continuing execution in the current fiber.
+# 6. If the listening fiber raises an exception, it is rescued and re-raised
+#    in the current fiber.
+def run_server(server)
+  server_done = Channel(Exception?).new
+
+  spawn do
+    server.listen
+  rescue exc
+    server_done.send exc
+  else
+    server_done.send nil
+  end
+
+  begin
+    wait_for { server.listening? }
+
+    yield server_done
+  ensure
+    server.close unless server.closed?
+
+    if exc = server_done.receive
+      raise exc
+    end
+  end
+end

spec/std/oauth2/client_spec.cr

@@ -1,5 +1,6 @@
 require "spec"
 require "oauth2"
+require "../http/spec_helper"
 
 describe OAuth2::Client do
   describe "authorization uri" do
@@ -38,11 +39,91 @@ describe OAuth2::Client do
     end
   end
 
+  describe "get_access_token_using_*" do
+    it "#get_access_token_using_authorization_code" do
+      server = HTTP::Server.new do |context|
+        body = context.request.body.not_nil!.gets_to_end
+        response = {access_token: "access_token", body: body}
+        context.response.print response.to_json
+      end
+
+      expected = %("client_id=client_id&client_secret=client_secret&redirect_uri=&grant_type=authorization_code&code=SDFhw39fwfg23flSfpawbef")
+      address = server.bind_unused_port "::1"
+
+      run_server(server) do
+        client = OAuth2::Client.new "[::1]", "client_id", "client_secret", port: address.port, scheme: "http"
+
+        token = client.get_access_token_using_authorization_code(authorization_code: "SDFhw39fwfg23flSfpawbef")
+        token.extra.not_nil!["body"].should eq expected
+        token.access_token.should eq "access_token"
+      end
+    end
+
+    it "#get_access_token_using_resource_owner_credentials" do
+      server = HTTP::Server.new do |context|
+        body = context.request.body.not_nil!.gets_to_end
+        response = {access_token: "access_token", body: body}
+        context.response.print response.to_json
+      end
+
+      expected = %("client_id=client_id&client_secret=client_secret&grant_type=password&username=user123&password=monkey&scope=read_posts")
+      address = server.bind_unused_port "::1"
+
+      run_server(server) do
+        client = OAuth2::Client.new "[::1]", "client_id", "client_secret", port: address.port, scheme: "http"
+
+        token = client.get_access_token_using_resource_owner_credentials(username: "user123", password: "monkey", scope: "read_posts")
+        token.extra.not_nil!["body"].should eq expected
+        token.access_token.should eq "access_token"
+      end
+    end
+
+    it "#get_access_token_using_client_credentials" do
+      server = HTTP::Server.new do |context|
+        body = context.request.body.not_nil!.gets_to_end
+        response = {access_token: "access_token", body: body}
+        context.response.print response.to_json
+      end
+
+      expected = %("client_id=client_id&client_secret=client_secret&grant_type=client_credentials&scope=read_posts")
+      address = server.bind_unused_port "::1"
+
+      run_server(server) do
+        client = OAuth2::Client.new "[::1]", "client_id", "client_secret", port: address.port, scheme: "http"
+
+        token = client.get_access_token_using_client_credentials(scope: "read_posts")
+        token.extra.not_nil!["body"].should eq expected
+        token.access_token.should eq "access_token"
+      end
+    end
+
+    it "#get_access_token_using_refresh_token" do
+      server = HTTP::Server.new do |context|
+        body = context.request.body.not_nil!.gets_to_end
+        response = {access_token: "access_token", body: body}
+        context.response.print response.to_json
+      end
+
+      expected = %("client_id=client_id&client_secret=client_secret&grant_type=refresh_token&refresh_token=some_refresh_token&scope=read_posts")
+      address = server.bind_unused_port "::1"
+
+      run_server(server) do
+        client = OAuth2::Client.new "[::1]", "client_id", "client_secret", port: address.port, scheme: "http"
+
+        token = client.get_access_token_using_refresh_token(scope: "read_posts", refresh_token: "some_refresh_token")
+        token.extra.not_nil!["body"].should eq expected
+        token.access_token.should eq "access_token"
+      end
+    end
+  end
+
   typeof(begin
     client = OAuth2::Client.new "localhost", "client_id", "client_secret", redirect_uri: "uri", authorize_uri: "/baz"
     client.get_access_token_using_authorization_code("some_code")
     client.get_access_token_using_refresh_token("some_refresh_token")
     client.get_access_token_using_refresh_token("some_refresh_token", scope: "some scope")
     client.get_access_token_using_client_credentials(scope: "some scope")
+    client.get_access_token_using_resource_owner_credentials(username: "user123", password: "monkey")
+    client.get_access_token_using_resource_owner_credentials(username: "user123", password: "monkey", scope: "foo")
   end)
 end

src/oauth2/client.cr

@@ -105,43 +105,55 @@ class OAuth2::Client
   end
 
   # Gets an access token using an authorization code, as specified by
-  # [RFC 6749, Section 4.1.1](https://tools.ietf.org/html/rfc6749#section-4.1.3).
-  def get_access_token_using_authorization_code(authorization_code) : AccessToken
+  # [RFC 6749, Section 4.1.3](https://tools.ietf.org/html/rfc6749#section-4.1.3).
+  def get_access_token_using_authorization_code(authorization_code : String) : AccessToken
     get_access_token do |form|
       form.add("redirect_uri", @redirect_uri)
       form.add("grant_type", "authorization_code")
       form.add("code", authorization_code)
     end
   end
 
-  # Gets an access token using a refresh token, as specified by
-  # [RFC 6749, Section 6](https://tools.ietf.org/html/rfc6749#section-6).
-  def get_access_token_using_refresh_token(refresh_token, scope = nil) : AccessToken
+  # Gets an access token using the resource owner credentials, as specified by
+  # [RFC 6749, Section 4.3.2](https://tools.ietf.org/html/rfc6749#section-4.3.2).
+  def get_access_token_using_resource_owner_credentials(username : String, password : String, scope = nil) : AccessToken
     get_access_token do |form|
-      form.add("grant_type", "refresh_token")
-      form.add("refresh_token", refresh_token)
-      form.add "scope", scope unless scope.nil?
+      form.add("grant_type", "password")
+      form.add("username", username)
+      form.add("password", password)
+      form.add("scope", scope) unless scope.nil?
     end
   end
 
   # Gets an access token using client credentials, as specified by
   # [RFC 6749, Section 4.4.2](https://tools.ietf.org/html/rfc6749#section-4.4.2).
-  def get_access_token_using_client_credentials(scope = nil)
+  def get_access_token_using_client_credentials(scope = nil) : AccessToken
     get_access_token do |form|
       form.add("grant_type", "client_credentials")
       form.add("scope", scope) unless scope.nil?
     end
   end
 
-  private def get_access_token
+  # Gets an access token using a refresh token, as specified by
+  # [RFC 6749, Section 6](https://tools.ietf.org/html/rfc6749#section-6).
+  def get_access_token_using_refresh_token(refresh_token, scope = nil) : AccessToken
+    get_access_token do |form|
+      form.add("grant_type", "refresh_token")
+      form.add("refresh_token", refresh_token)
+      form.add "scope", scope unless scope.nil?
+    end
+  end
+
+  private def get_access_token : AccessToken
     body = HTTP::Params.build do |form|
       form.add("client_id", @client_id)
       form.add("client_secret", @client_secret)
       yield form
     end
 
     headers = HTTP::Headers{
-      "Accept" => "application/json",
+      "Accept"       => "application/json",
+      "Content-Type" => "application/x-www-form-urlencoded",
     }
 
     response = HTTP::Client.post(token_uri, form: body, headers: headers)