Working OAuth2 support. Needs some more debugging (error handling is not

great and imc_logout() gets (rightfully) confused when jabber_data is empty).

3 files changed, 158 insertions, 34 deletions

diff --git a/lib/oauth.h b/lib/oauth.h
index 8270a545..5c4ef4b0 100644
--- a/lib/oauth.h
+++ b/lib/oauth.h
@@ -91,4 +91,7 @@ char *oauth_to_string( struct oauth_info *oi );
 struct oauth_info *oauth_from_string( char *in, const struct oauth_service *sp );
 
 /* For reading misc. data. */
+void oauth_params_add( GSList **params, const char *key, const char *value );
+void oauth_params_free( GSList **params );
+char *oauth_params_string( GSList *params );
 const char *oauth_params_get( GSList **params, const char *key );
diff --git a/lib/oauth2.c b/lib/oauth2.c
index eb923795..d9eefa9f 100644
--- a/lib/oauth2.c
+++ b/lib/oauth2.c
@@ -22,7 +22,10 @@
 \***************************************************************************/
 
 #include <glib.h>
+#include "http_client.h"
 #include "oauth2.h"
+#include "oauth.h"
+#include "url.h"
 
 struct oauth2_service oauth2_service_google =
 {
@@ -40,3 +43,139 @@ char *oauth2_url( const struct oauth2_service *sp, const char *scope )
 	                    "&client_id=", sp->consumer_key,
 	                    NULL );
 }
+
+struct oauth2_access_token_data
+{
+	oauth2_token_callback func;
+	gpointer data;
+};
+
+static char *oauth2_json_dumb_get( const char *json, const char *key );
+static void oauth2_access_token_done( struct http_request *req );
+
+int oauth2_access_token( const struct oauth2_service *sp,
+                         const char *auth_type, const char *auth,
+                         oauth2_token_callback func, gpointer data )
+{
+	GSList *args = NULL;
+	char *args_s, *s;
+	url_t url_p;
+	struct http_request *req;
+	struct oauth2_access_token_data *cb_data;
+	
+	if( !url_set( &url_p, sp->base_url ) )
+		return 0;
+	
+	oauth_params_add( &args, "client_id", sp->consumer_key );
+	oauth_params_add( &args, "client_secret", sp->consumer_secret );
+	oauth_params_add( &args, "grant_type", auth_type );
+	if( strcmp( auth_type, OAUTH2_AUTH_CODE ) == 0 )
+	{
+		oauth_params_add( &args, "redirect_uri", "urn:ietf:wg:oauth:2.0:oob" );
+		oauth_params_add( &args, "code", auth );
+	}
+	else
+	{
+		oauth_params_add( &args, "refresh_token", auth );
+	}
+	args_s = oauth_params_string( args );
+	oauth_params_free( &args );
+	
+	s = g_strdup_printf( "POST %s%s HTTP/1.0\r\n"
+	                     "Host: %s\r\n"
+	                     "Content-Type: application/x-www-form-urlencoded\r\n"
+	                     "Content-Length: %zd\r\n"
+	                     "Connection: close\r\n"
+	                     "\r\n"
+	                     "%s", url_p.file, "token", url_p.host, strlen( args_s ), args_s );
+	g_free( args_s );
+	
+	cb_data = g_new0( struct oauth2_access_token_data, 1 );
+	cb_data->func = func;
+	cb_data->data = data;
+	
+	req = http_dorequest( url_p.host, url_p.port, url_p.proto == PROTO_HTTPS,
+	                      s, oauth2_access_token_done, cb_data );
+	
+	g_free( s );
+	
+	if( req == NULL )
+		g_free( cb_data );
+	
+	return req != NULL;
+}
+
+static void oauth2_access_token_done( struct http_request *req )
+{
+	struct oauth2_access_token_data *cb_data = req->data;
+	char *atoken = NULL, *rtoken = NULL;
+	
+	if( req->status_code == 200 )
+	{
+		atoken = oauth2_json_dumb_get( req->reply_body, "access_token" );
+		rtoken = oauth2_json_dumb_get( req->reply_body, "refresh_token" );
+	}
+	cb_data->func( cb_data->data, atoken, rtoken );
+	g_free( atoken );
+	g_free( rtoken );
+	g_free( cb_data );
+}
+
+/* Super dumb. I absolutely refuse to use/add a complete json parser library
+   (adding a new dependency to BitlBee for the first time in.. 6 years?) just
+   to parse 100 bytes of data. So I have to do my own parsing because OAuth2
+   dropped support for XML. (GRRR!) This is very dumb and for example won't
+   work for integer values, nor will it strip/handle backslashes. */
+static char *oauth2_json_dumb_get( const char *json, const char *key )
+{
+	int is_key; /* 1 == reading key, 0 == reading value */
+	int found_key = 0;
+		
+	while( json && *json )
+	{
+		/* Grab strings and see if they're what we're looking for. */
+		if( *json == '"' || *json == '\'' )
+		{
+			char q = *json;
+			const char *str_start;
+			json ++;
+			str_start = json;
+			
+			while( *json )
+			{
+				/* \' and \" are not string terminators. */
+				if( *json == '\\' && json[1] == q )
+					json ++;
+				/* But without a \ it is. */
+				else if( *json == q )
+					break;
+				json ++;
+			}
+			if( *json == '\0' )
+				return NULL;
+			
+			if( is_key && strncmp( str_start, key, strlen( key ) ) == 0 )
+			{
+				found_key = 1;
+			}
+			else if( !is_key && found_key )
+			{
+				char *ret = g_memdup( str_start, json - str_start + 1 );
+				ret[json-str_start] = '\0';
+				return ret;
+			}
+			
+		}
+		else if( *json == '{' || *json == ',' )
+		{
+			found_key = 0;
+			is_key = 1;
+		}
+		else if( *json == ':' )
+			is_key = 0;
+		
+		json ++;
+	}
+	
+	return NULL;
+}
diff --git a/lib/oauth2.h b/lib/oauth2.h
index c2985ef6..657a0ab3 100644
--- a/lib/oauth2.h
+++ b/lib/oauth2.h
@@ -1,7 +1,7 @@
 /***************************************************************************\
 *                                                                           *
 *  BitlBee - An IRC to IM gateway                                           *
-*  Simple OAuth client (consumer) implementation.                           *
+*  Simple OAuth2 client (consumer) implementation.                          *
 *                                                                           *
 *  Copyright 2010-2011 Wilmer van der Gaast <wilmer@gaast.net>              *
 *                                                                           *
@@ -21,28 +21,10 @@
 *                                                                           *
 \***************************************************************************/
 
-struct oauth2_info;
+/* Implementation mostly based on my experience with writing the previous OAuth
+   module, and from http://code.google.com/apis/accounts/docs/OAuth2.html . */
 
-/* Callback function called twice during the access token request process.
-   Return FALSE if something broke and the process must be aborted. */
-typedef gboolean (*oauth_cb)( struct oauth2_info * );
-
-struct oauth2_info
-{
-	const struct oauth_service *sp;
-	
-	oauth_cb func;
-	void *data;
-	
-	struct http_request *http;
-	
-//	char *auth_url;
-//	char *request_token;
-	
-//	char *token;
-//	char *token_secret;
-//	GSList *params;
-};
+typedef void (*oauth2_token_callback)( gpointer data, const char *atoken, const char *rtoken );
 
 struct oauth2_service
 {
@@ -51,19 +33,19 @@ struct oauth2_service
 	char *consumer_secret;
 };
 
+/* Currently suitable for authenticating to Google Talk only, and only for
+   accounts that have 2-factor authorization enabled. */
 extern struct oauth2_service oauth2_service_google;
 
-/* http://oauth.net/core/1.0a/#auth_step1 (section 6.1) 
-   Request an initial anonymous token which can be used to construct an
-   authorization URL for the user. This is passed to the callback function
-   in a struct oauth2_info. */
-char *oauth2_url( const struct oauth2_service *sp, const char *scope );
+#define OAUTH2_AUTH_CODE "authorization_code"
+#define OAUTH2_AUTH_REFRESH "refresh_token"
 
-/* http://oauth.net/core/1.0a/#auth_step3 (section 6.3)
-   The user gets a PIN or so which we now exchange for the final access
-   token. This is passed to the callback function in the same
-   struct oauth2_info. */
-gboolean oauth2_access_token( const char *pin, struct oauth2_info *st );
+/* Generate a URL the user should open in his/her browser to get an
+   authorization code. */
+char *oauth2_url( const struct oauth2_service *sp, const char *scope );
 
-/* Shouldn't normally be required unless the process is aborted by the user. */
-void oauth2_info_free( struct oauth2_info *info );
+/* Exchanges an auth code or refresh token for an access token.
+   auth_type is one of the two OAUTH2_AUTH_.. constants above. */
+int oauth2_access_token( const struct oauth2_service *sp,
+                         const char *auth_type, const char *auth,
+                         oauth2_token_callback func, gpointer data );