Move CamelSaslXOAuth2 to libemail-engine.

This now uses e_source_get_oauth2_access_token_sync() instead of talking
directly to GNOME Online Accounts and therefore no longer has to live in
the "online-accounts" module.

The "online-accounts" module will be removed in Evolution 3.9.1, when we
can require GNOME Online Accounts 3.8.  Evolution 3.8 will still support
older versions of GNOME Online Accounts, which use OAuth 1.0a tokens for
Google authentication.

4 files changed, 202 insertions, 0 deletions

diff --git a/libemail-engine/Makefile.am b/libemail-engine/Makefile.am
index 215d48e934..60a8437c6e 100644
--- a/libemail-engine/Makefile.am
+++ b/libemail-engine/Makefile.am
@@ -25,6 +25,7 @@ libemail_engine_la_CPPFLAGS = \
 libmailengineincludedir = $(privincludedir)/libemail-engine
 libmailengineinclude_HEADERS =  \
 	camel-null-store.h \
+	camel-sasl-xoauth2.h \
 	e-mail-authenticator.h \
 	e-mail-enums.h \
 	e-mail-enumtypes.h \
@@ -48,6 +49,7 @@ libmailengineinclude_HEADERS =  \
 libemail_engine_la_SOURCES =  \
 	$(libmailengineinclude_HEADERS) \
 	camel-null-store.c \
+	camel-sasl-xoauth2.c \
 	e-mail-authenticator.c \
 	e-mail-enumtypes.c \
 	e-mail-folder-utils.c \
diff --git a/libemail-engine/camel-sasl-xoauth2.c b/libemail-engine/camel-sasl-xoauth2.c
new file mode 100644
index 0000000000..3cf43e7393
--- /dev/null
+++ b/libemail-engine/camel-sasl-xoauth2.c
@@ -0,0 +1,131 @@
+/*
+ * camel-sasl-xoauth2.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) version 3.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with the program; if not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+#include <config.h>
+#include <glib/gi18n-lib.h>
+
+#include "camel-sasl-xoauth2.h"
+
+#include <libemail-engine/e-mail-session.h>
+
+static CamelServiceAuthType sasl_xoauth2_auth_type = {
+	N_("OAuth2"),
+	N_("This option will use an OAuth 2.0 "
+	   "access token to connect to the server"),
+	"XOAUTH2",
+	FALSE
+};
+
+G_DEFINE_TYPE (CamelSaslXOAuth2, camel_sasl_xoauth2, CAMEL_TYPE_SASL)
+
+static void
+sasl_xoauth2_append_request (GByteArray *byte_array,
+                             const gchar *user,
+                             const gchar *access_token)
+{
+	GString *request;
+
+	g_return_if_fail (user != NULL);
+	g_return_if_fail (access_token != NULL);
+
+	/* Compared to OAuth 1.0, this step is trivial. */
+
+	/* The request is easier to assemble with a GString. */
+	request = g_string_sized_new (512);
+
+	g_string_append (request, "user=");
+	g_string_append (request, user);
+	g_string_append_c (request, 1);
+	g_string_append (request, "auth=Bearer ");
+	g_string_append (request, access_token);
+	g_string_append_c (request, 1);
+	g_string_append_c (request, 1);
+
+	/* Copy the GString content to the GByteArray. */
+	g_byte_array_append (
+		byte_array, (guint8 *) request->str, request->len);
+
+	g_string_free (request, TRUE);
+}
+
+static GByteArray *
+sasl_xoauth2_challenge_sync (CamelSasl *sasl,
+                             GByteArray *token,
+                             GCancellable *cancellable,
+                             GError **error)
+{
+	GByteArray *byte_array = NULL;
+	CamelService *service;
+	CamelSession *session;
+	CamelSettings *settings;
+	ESourceRegistry *registry;
+	ESource *source;
+	const gchar *uid;
+	gchar *access_token = NULL;
+	gboolean success;
+
+	service = camel_sasl_get_service (sasl);
+	session = camel_service_get_session (service);
+	settings = camel_service_ref_settings (service);
+
+	uid = camel_service_get_uid (service);
+	registry = e_mail_session_get_registry (E_MAIL_SESSION (session));
+	source = e_source_registry_ref_source (registry, uid);
+	g_return_val_if_fail (source != NULL, NULL);
+
+	success = e_source_get_oauth2_access_token_sync (
+		source, cancellable, &access_token, NULL, error);
+
+	if (success) {
+		CamelNetworkSettings *network_settings;
+		gchar *user;
+
+		network_settings = CAMEL_NETWORK_SETTINGS (settings);
+		user = camel_network_settings_dup_user (network_settings);
+
+		byte_array = g_byte_array_new ();
+		sasl_xoauth2_append_request (byte_array, user, access_token);
+
+		g_free (user);
+	}
+
+	g_free (access_token);
+
+	g_object_unref (source);
+	g_object_unref (settings);
+
+	/* IMAP and SMTP services will Base64-encode the request. */
+
+	return byte_array;
+}
+
+static void
+camel_sasl_xoauth2_class_init (CamelSaslXOAuth2Class *class)
+{
+	CamelSaslClass *sasl_class;
+
+	sasl_class = CAMEL_SASL_CLASS (class);
+	sasl_class->auth_type = &sasl_xoauth2_auth_type;
+	sasl_class->challenge_sync = sasl_xoauth2_challenge_sync;
+}
+
+static void
+camel_sasl_xoauth2_init (CamelSaslXOAuth2 *sasl)
+{
+}
+
diff --git a/libemail-engine/camel-sasl-xoauth2.h b/libemail-engine/camel-sasl-xoauth2.h
new file mode 100644
index 0000000000..940964b498
--- /dev/null
+++ b/libemail-engine/camel-sasl-xoauth2.h
@@ -0,0 +1,63 @@
+/*
+ * camel-sasl-xoauth2.h
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) version 3.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with the program; if not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+#ifndef CAMEL_SASL_XOAUTH2_H
+#define CAMEL_SASL_XOAUTH2_H
+
+#include <camel/camel.h>
+
+/* Standard GObject macros */
+#define CAMEL_TYPE_SASL_XOAUTH2 \
+	(camel_sasl_xoauth2_get_type ())
+#define CAMEL_SASL_XOAUTH2(obj) \
+	(G_TYPE_CHECK_INSTANCE_CAST \
+	((obj), CAMEL_TYPE_SASL_XOAUTH2, CamelSaslXOAuth2))
+#define CAMEL_SASL_XOAUTH2_CLASS(cls) \
+	(G_TYPE_CHECK_CLASS_CAST \
+	((cls), CAMEL_TYPE_SASL_XOAUTH2, CamelSaslXOAuth2Class))
+#define CAMEL_IS_SASL_XOAUTH2(obj) \
+	(G_TYPE_CHECK_INSTANCE_TYPE \
+	((obj), CAMEL_TYPE_SASL_XOAUTH2))
+#define CAMEL_IS_SASL_XOAUTH2_CLASS(cls) \
+	(G_TYPE_CHECK_CLASS_TYPE \
+	((cls), CAMEL_TYPE_SASL_XOAUTH2))
+#define CAMEL_SASL_XOAUTH2_GET_CLASS(obj) \
+	(G_TYPE_INSTANCE_GET_CLASS \
+	((obj), CAMEL_TYPE_SASL_XOAUTH2, CamelSaslXOAuth2Class))
+
+G_BEGIN_DECLS
+
+typedef struct _CamelSaslXOAuth2 CamelSaslXOAuth2;
+typedef struct _CamelSaslXOAuth2Class CamelSaslXOAuth2Class;
+typedef struct _CamelSaslXOAuth2Private CamelSaslXOAuth2Private;
+
+struct _CamelSaslXOAuth2 {
+	CamelSasl parent;
+	CamelSaslXOAuth2Private *priv;
+};
+
+struct _CamelSaslXOAuth2Class {
+	CamelSaslClass parent_class;
+};
+
+GType		camel_sasl_xoauth2_get_type	(void) G_GNUC_CONST;
+
+G_END_DECLS
+
+#endif /* CAMEL_SASL_XOAUTH2_H */
+
diff --git a/libemail-engine/e-mail-session.c b/libemail-engine/e-mail-session.c
index 30a83d4230..b195238145 100644
--- a/libemail-engine/e-mail-session.c
+++ b/libemail-engine/e-mail-session.c
@@ -51,6 +51,9 @@
 /* This is our hack, not part of libcamel. */
 #include "camel-null-store.h"
 
+/* This too, though it's less of a hack. */
+#include "camel-sasl-xoauth2.h"
+
 #include "e-mail-authenticator.h"
 #include "e-mail-junk-filter.h"
 #include "e-mail-session.h"
@@ -1963,6 +1966,9 @@ e_mail_session_class_init (EMailSessionClass *class)
 
 	/* Make sure ESourceCamel picks up the "none" provider. */
 	e_source_camel_generate_subtype ("none", CAMEL_TYPE_SETTINGS);
+
+	/* Make sure CamelSasl picks up the XOAUTH2 mechanism. */
+	g_type_ensure (CAMEL_TYPE_SASL_XOAUTH2);
 }
 
 static void