Enable credentials using browser obtained token and cookie.

The way it works is that you need two tokens from the browser.
Currently, getting them is inconvenient, but let's start with the
basics, and we can improve later.

1. Get the main token by entering the browser devtools while logged
   into Slack (normally F12). From there, select "Storage", then
   "Local Storage", "https://app.slack.com" and "localConfig_v2". From
   inside this value, fish out the value of the "token" key, which
   starts with "xoxc-". Make sure to get the whole token, and not the
   surrounding quotes. Paste this value in some temporary place.

2. Now move from "Local Storage" to "Cookies", and again
   "https://app.slack.com". Copy the value of the "d" cookie, which
   starts with "xoxd-". Paste this value after the one from the
   previous step, with exactly one space in between.

3. Take the two concatenated values, and paste them into the password
   field of the Slack account. The value should look like this:
   "xoxc-12345 xoxd-67890" (but much longer obviously).

About the implementation: This requires using form based submission,
because the JSON based API is broken and does not return the correct
data, even with the same parameters (see issue #123). Therefore the
way the token is passed, even the single token which already worked,
is now changed to form data.

Since `slack_api_get` is no longer a valid call when form based
submission is used (it requires post), this function has been removed.

Signed-off-by: Kristian Amlie <kristian.amlie@northern.tech>

slack-api.c

@@ -108,49 +108,48 @@ static void api_run(SlackAccount *sa) {
 	api_retry(call);
 }
 
-static GString *slack_api_encode_url(SlackAccount *sa, const char *pfx, const char *endpoint, va_list qargs) {
-	GString *url = g_string_new(NULL);
-	g_string_printf(url, "%s/%s%s?token=%s", sa->api_url, pfx, endpoint, sa->token);
-
-	const char *param;
-	while ((param = va_arg(qargs, const char*))) {
-		const char *val = va_arg(qargs, const char*);
-		g_string_append_printf(url, "&%s=%s", param, purple_url_encode(val));
-	}
-
-	return url;
-}
-
 static char *slack_api_encode_post_request(SlackAccount *sa, const char *url, va_list qargs) {
 	GString *request;
 	gchar *host = NULL, *path = NULL;
 	purple_url_parse(url, &host, NULL, &path, NULL, NULL);
 
 	GString *postdata;
 	const char *param;
-	gboolean sep = FALSE;
 
-	postdata = g_string_new("{");
+	// Just a long random number.
+	guint64 delim = ((guint64)g_random_int() << 32) | (guint64)g_random_int();
+
+	postdata = g_string_new("");
+	g_string_printf(postdata, "-----------------------------%" G_GUINT64_FORMAT "\r\n", delim);
 	while ((param = va_arg(qargs, const char*))) {
 		const char *val = va_arg(qargs, const char*);
-		if (sep)
-			g_string_append_c(postdata, ',');
-		append_json_string(postdata, param);
-		g_string_append_c(postdata, ':');
-		append_json_string(postdata, val);
-		sep = TRUE;
+		g_string_append_printf(postdata, "\
+Content-Disposition: form-data; name=\"%s\"\r\n\
+\r\n\
+%s\r\n\
+-----------------------------%" G_GUINT64_FORMAT "\r\n",
+			param, val, delim);
 	}
-	g_string_append_c(postdata, '}');
+
+	g_string_append_printf(postdata,
+"Content-Disposition: form-data; name=\"token\"\r\n\
+\r\n\
+%s\r\n\
+-----------------------------%" G_GUINT64_FORMAT "\r\n",
+		sa->token, delim);
 
 	request = g_string_new(NULL);
 	g_string_append_printf(request, "\
 POST /%s HTTP/1.0\r\n\
 Host: %s\r\n\
-Authorization: Bearer %s\r\n\
-Content-Type: application/json;charset=utf-8\r\n\
-Content-Length: %" G_GSIZE_FORMAT "\r\n\
-\r\n",
-		path, host, sa->token, postdata->len);
+Content-Type: multipart/form-data; boundary=---------------------------%" G_GUINT64_FORMAT "\r\n\
+Content-Length: %" G_GSIZE_FORMAT "\r\n",
+		path, host, delim, postdata->len);
+
+	if (sa->d_cookie) {
+		g_string_append_printf(request, "Cookie: d=%s\r\n", sa->d_cookie);
+	}
+	g_string_append(request, "\r\n");
 	g_string_append(request, postdata->str);
 
 	g_free(host);
@@ -174,18 +173,6 @@ static void slack_api_call_url(SlackAccount *sa, SlackAPICallback callback, gpoi
 		api_retry(call);
 }
 
-void slack_api_get(SlackAccount *sa, SlackAPICallback callback, gpointer user_data, const char *endpoint, ...)
-{
-	va_list qargs;
-	va_start(qargs, endpoint);
-	GString *url = slack_api_encode_url(sa, "", endpoint, qargs);
-	va_end(qargs);
-
-	slack_api_call_url(sa, callback, user_data, url->str, NULL);
-
-	g_string_free(url, TRUE);
-}
-
 void slack_api_post(SlackAccount *sa, SlackAPICallback callback, gpointer user_data, const gchar *endpoint, ...)
 {
 	GString *url = g_string_new(NULL);

slack-api.h

@@ -10,7 +10,6 @@ PurpleConnectionError slack_api_connection_error(const gchar *error);
 typedef struct _SlackAPICall SlackAPICall;
 typedef gboolean SlackAPICallback(SlackAccount *sa, gpointer user_data, json_value *json, const char *error);
 
-void slack_api_get(SlackAccount *sa, SlackAPICallback *callback, gpointer user_data, const char *endpoint, /* const char *query_param1, const char *query_value1, */ ...) G_GNUC_NULL_TERMINATED;
 void slack_api_post(SlackAccount *sa, SlackAPICallback *callback, gpointer user_data, const char *endpoint, /* const char *query_param1, const char *query_value1, */ ...) G_GNUC_NULL_TERMINATED;
 void slack_api_disconnect(SlackAccount *sa);
 

slack-auth.c

@@ -49,7 +49,7 @@ slack_auth_login_finduser_cb(SlackAccount *sa, gpointer user_data, json_value *j
 
 	/* now do the actual login */
 	slack_login_step(sa);
-	slack_api_get(sa, slack_auth_login_signin_cb,
+	slack_api_post(sa, slack_auth_login_signin_cb,
 		NULL, "auth.signin",
 		"user", user_id,
 		"password", purple_account_get_password(sa->account),
@@ -75,7 +75,7 @@ slack_auth_login_findteam_cb(SlackAccount *sa, gpointer user_data, json_value *j
 
 	/* now validate that the user exists and get their ID. */
 	slack_login_step(sa);
-	slack_api_get(sa, slack_auth_login_finduser_cb,
+	slack_api_post(sa, slack_auth_login_finduser_cb,
 		NULL, "auth.findUser",
 		"email", sa->email,
 		"team", sa->team.id,
@@ -86,7 +86,7 @@ slack_auth_login_findteam_cb(SlackAccount *sa, gpointer user_data, json_value *j
 void
 slack_auth_login(SlackAccount *sa) {
 	/* validate the team and get it's ID */
-	slack_api_get(sa, slack_auth_login_findteam_cb,
+	slack_api_post(sa, slack_auth_login_findteam_cb,
 		NULL, "auth.findTeam",
 		"domain", sa->host,
 		NULL);

slack-blist.c

@@ -145,7 +145,7 @@ struct roomlist_expand {
 };
 
 #define ROOMLIST_CALL(sa, expand, ARGS...) \
-	slack_api_get(sa, roomlist_cb, expand, "conversations.list", "exclude_archived", expand->parent ? "false" : "true", "type", "public_channel,private_channel,mpim,im", SLACK_PAGINATE_LIMIT_ARG, ##ARGS, NULL)
+	slack_api_post(sa, roomlist_cb, expand, "conversations.list", "exclude_archived", expand->parent ? "false" : "true", "type", "public_channel,private_channel,mpim,im", SLACK_PAGINATE_LIMIT_ARG, ##ARGS, NULL)
 
 static gboolean roomlist_cb(SlackAccount *sa, gpointer data, json_value *json, const char *error) {
 	struct roomlist_expand *expand = data;

slack-channel.c

@@ -179,7 +179,7 @@ static gboolean channels_members_cb(SlackAccount *sa, gpointer data, json_value
 	json_value *metadata = json_get_prop_type(json, "response_metadata", object);
 	char *next_cursor = json_get_prop_strptr(metadata, "next_cursor");
 	if (strcmp(next_cursor, "")) {
-		slack_api_get(sa, channels_members_cb, chan, "conversations.members", "channel", chan->object.id, "cursor", next_cursor, NULL);
+		slack_api_post(sa, channels_members_cb, chan, "conversations.members", "channel", chan->object.id, "cursor", next_cursor, NULL);
 	}
 
 	return FALSE;
@@ -206,7 +206,7 @@ static gboolean channels_info_cb(SlackAccount *sa, gpointer data, json_value *js
 	}
 
 	if (purple_account_get_bool(sa->account, "channel_members", TRUE))
-		slack_api_get(sa, channels_members_cb, chan, "conversations.members", "channel", chan->object.id, NULL);
+		slack_api_post(sa, channels_members_cb, chan, "conversations.members", "channel", chan->object.id, NULL);
 
 	if (purple_account_get_bool(sa->account, "open_history", FALSE)) {
 		slack_get_history_unread(sa, &chan->object, json);
@@ -225,7 +225,7 @@ void slack_chat_open(SlackAccount *sa, SlackChannel *chan) {
 
 	serv_got_joined_chat(sa->gc, chan->cid, chan->object.name);
 
-	slack_api_get(sa, channels_info_cb, GINT_TO_POINTER(chan->type), "conversations.info", "channel", chan->object.id, NULL);
+	slack_api_post(sa, channels_info_cb, GINT_TO_POINTER(chan->type), "conversations.info", "channel", chan->object.id, NULL);
 }
 
 static gboolean channels_join_cb(SlackAccount *sa, gpointer data, json_value *json, const char *error) {

slack-conversation.c

@@ -16,7 +16,7 @@ static SlackObject *conversation_update(SlackAccount *sa, json_value *json) {
 }
 
 #define CONVERSATIONS_LIST_CALL(sa, ARGS...) \
-	slack_api_get(sa, conversations_list_cb, NULL, "conversations.list", "types", "public_channel,private_channel,mpim,im", "exclude_archived", "true", SLACK_PAGINATE_LIMIT_ARG, ##ARGS, NULL)
+	slack_api_post(sa, conversations_list_cb, NULL, "conversations.list", "types", "public_channel,private_channel,mpim,im", "exclude_archived", "true", SLACK_PAGINATE_LIMIT_ARG, ##ARGS, NULL)
 
 static gboolean conversations_list_cb(SlackAccount *sa, gpointer data, json_value *json, const char *error) {
 	json_value *chans = json_get_prop_type(json, "channels", array);
@@ -101,7 +101,7 @@ static gboolean conversation_counts_cb(SlackAccount *sa, gpointer data, json_val
 
 void slack_conversation_counts(SlackAccount *sa) {
 	/* Private API, not documented. Found by EionRobb (Github). */
-	slack_api_get(sa, conversation_counts_cb, NULL, "users.counts", "mpim_aware", "true", "only_relevant_ims", "true", "simple_unreads", "true", NULL);
+	slack_api_post(sa, conversation_counts_cb, NULL, "users.counts", "mpim_aware", "true", "only_relevant_ims", "true", "simple_unreads", "true", NULL);
 }
 
 SlackObject *slack_conversation_get_conversation(SlackAccount *sa, PurpleConversation *conv) {
@@ -158,7 +158,7 @@ void slack_conversation_retrieve(SlackAccount *sa, const char *sid, SlackConvers
 	struct conversation_retrieve *lookup = g_new(struct conversation_retrieve, 1);
 	lookup->cb = cb;
 	lookup->data = data;
-	slack_api_get(sa, conversation_retrieve_cb, lookup, "conversations.info", "channel", sid, NULL);
+	slack_api_post(sa, conversation_retrieve_cb, lookup, "conversations.info", "channel", sid, NULL);
 }
 
 static gboolean mark_conversation_timer(gpointer data) {
@@ -323,9 +323,9 @@ void slack_get_history(SlackAccount *sa, SlackObject *conv, const char *since, u
 	char count_buf[6] = "";
 	snprintf(count_buf, 5, "%u", MIN(count, SLACK_HISTORY_LIMIT_COUNT));
 	if (thread_ts)
-		slack_api_get(sa, get_history_cb, h, "conversations.replies", "channel", id, "oldest", since ?: "0", "limit", count_buf, "ts", thread_ts, NULL);
+		slack_api_post(sa, get_history_cb, h, "conversations.replies", "channel", id, "oldest", since ?: "0", "limit", count_buf, "ts", thread_ts, NULL);
 	else
-		slack_api_get(sa, get_history_cb, h, "conversations.history", "channel", id, "oldest", since ?: "0", "limit", count_buf, NULL);
+		slack_api_post(sa, get_history_cb, h, "conversations.history", "channel", id, "oldest", since ?: "0", "limit", count_buf, NULL);
 }
 
 void slack_get_history_unread(SlackAccount *sa, SlackObject *conv, json_value *json) {
@@ -353,5 +353,5 @@ static gboolean get_conversation_unread_cb(SlackAccount *sa, gpointer data, json
 void slack_get_conversation_unread(SlackAccount *sa, SlackObject *conv) {
 	const char *id = slack_conversation_id(conv);
 	g_return_if_fail(id);
-	slack_api_get(sa, get_conversation_unread_cb, g_object_ref(conv), "conversations.info", "channel", id, NULL);
+	slack_api_post(sa, get_conversation_unread_cb, g_object_ref(conv), "conversations.info", "channel", id, NULL);
 }

slack-rtm.c

@@ -232,5 +232,5 @@ void slack_rtm_send(SlackAccount *sa, SlackRTMCallback *callback, gpointer user_
 }
 
 void slack_rtm_connect(SlackAccount *sa) {
-	slack_api_get(sa, rtm_connect_cb, NULL, "rtm.connect", "batch_presence_aware", "1", "presence_sub", "true", NULL);
+	slack_api_post(sa, rtm_connect_cb, NULL, "rtm.connect", "batch_presence_aware", "1", "presence_sub", "true", NULL);
 }

slack-thread.c

@@ -251,7 +251,7 @@ static void slack_thread_lookup_ts(SlackAccount *sa, slack_thread_lookup_ts_cb *
 	lookup->rest = g_strdup(rest);
 
 	const char *id = slack_conversation_id(conv);
-	slack_api_get(sa, slack_thread_lookup_ts_history_cb, lookup, "conversations.history", "channel", id, "oldest", start, "latest", end, "inclusive", "1", NULL);
+	slack_api_post(sa, slack_thread_lookup_ts_history_cb, lookup, "conversations.history", "channel", id, "oldest", start, "latest", end, "inclusive", "1", NULL);
 }
 
 static void slack_thread_post_lookup_cb(SlackAccount *sa, SlackObject *conv, gpointer data, const char *thread_ts, const char *msg) {

slack-user.c

@@ -120,15 +120,15 @@ static gboolean users_list_cb(SlackAccount *sa, gpointer data, json_value *json,
 
 	char *cursor = json_get_prop_strptr1(json_get_prop(json, "response_metadata"), "next_cursor");
 	if (cursor)
-		slack_api_get(sa, users_list_cb, NULL, "users.list", "presence", "false", SLACK_PAGINATE_LIMIT_ARG, "cursor", cursor, NULL);
+		slack_api_post(sa, users_list_cb, NULL, "users.list", "presence", "false", SLACK_PAGINATE_LIMIT_ARG, "cursor", cursor, NULL);
 	else
 		slack_login_step(sa);
 	return FALSE;
 }
 
 void slack_users_load(SlackAccount *sa) {
 	// g_hash_table_remove_all(sa->users); /* this isn't really necessary, and we'd prefer to preserve self */
-	slack_api_get(sa, users_list_cb, NULL, "users.list", "presence", "false", SLACK_PAGINATE_LIMIT_ARG, NULL);
+	slack_api_post(sa, users_list_cb, NULL, "users.list", "presence", "false", SLACK_PAGINATE_LIMIT_ARG, NULL);
 }
 
 struct user_retrieve {
@@ -156,7 +156,7 @@ void slack_user_retrieve(SlackAccount *sa, const char *uid, SlackUserCallback *c
 	struct user_retrieve *lookup = g_new(struct user_retrieve, 1);
 	lookup->cb = cb;
 	lookup->data = data;
-	slack_api_get(sa, user_retrieve_cb, lookup, "users.info", "user", uid, NULL);
+	slack_api_post(sa, user_retrieve_cb, lookup, "users.info", "user", uid, NULL);
 }
 
 static void presence_set(SlackAccount *sa, json_value *json, const char *presence) {
@@ -272,7 +272,7 @@ void slack_get_info(PurpleConnection *gc, const char *who) {
 	if (!user)
 		users_info_cb(sa, g_strdup(who), NULL, NULL);
 	else
-		slack_api_get(sa, users_info_cb, g_strdup(who), "users.info", "user", user->object.id, NULL);
+		slack_api_post(sa, users_info_cb, g_strdup(who), "users.info", "user", user->object.id, NULL);
 }
 
 static void avatar_load_next(SlackAccount *sa);

slack.c

@@ -282,14 +282,35 @@ static void slack_login(PurpleAccount *account) {
 	/* check if a token has been stored in the password field. */
 	const char *password = purple_account_get_password(sa->account);
 	if(g_regex_match_simple("^xox.-.+", password, 0, 0)) {
-		/* the password is a token, so copy it to the token field */
-		sa->token = g_strdup(password);
+		/* The password is a token. There might be one or two tokens
+		   depending on whether we are using the cookie token or not. */
+		gchar **tokens = g_regex_split_simple(" +", password, 0, 0);
+		gboolean normal_token = FALSE;
+		gboolean cookie_token = FALSE;
+		for (int c = 0; tokens[c] != NULL; c++) {
+			/* copy to the respective token field */
+			if (!cookie_token && strncmp("xoxd-", tokens[c], 5) == 0) {
+				sa->d_cookie = g_strdup(tokens[c]);
+				cookie_token = TRUE;
+			} else if (!normal_token) {
+				sa->token = g_strdup(tokens[c]);
+				normal_token = TRUE;
+			} else {
+				purple_connection_error_reason(
+					purple_account_get_connection(sa->account),
+					PURPLE_CONNECTION_ERROR_AUTHENTICATION_FAILED,
+					"Wrong number of auth tokens.");
+				return;
+			}
+		}
+		g_strfreev(tokens);
 
 		/* set the api url to the property host */
 		sa->api_url = g_strdup_printf("https://%s/api", sa->host);
 
 		/* finally skip the mobile login as we already have a token */
 		sa->login_step = 3;
+
 	} else {
 		if(!password || !*password) {
 			purple_connection_error_reason(
@@ -409,6 +430,7 @@ static void slack_close(PurpleConnection *gc) {
 	g_object_unref(sa->self);
 
 	g_free(sa->api_url);
+	g_free(sa->d_cookie);
 	g_free(sa->token);
 	g_free(sa->email);
 	g_free(sa->host);

slack.h

@@ -20,6 +20,7 @@ typedef struct _SlackAccount {
 	char *host;
 	char *api_url; /* e.g., "https://slack.com/api" */
 	char *token; /* url encoded */
+	char *d_cookie;
 
 	short login_step;
 	GQueue api_calls; /* SlackAPICall */