f-list_nssfix.c

#include <glib.h>

// libpurple
#include "debug.h"
#include "plugin.h"
#include "sslconn.h"
#include "version.h"

// NSS
#include <ssl.h>

#define FLIST_NSSFIX_PLUGIN_ID "flist_nssfix"

typedef struct
{
	PRFileDesc *fd;
	PRFileDesc *in;
	guint handshake_handler;
	guint handshake_timer;
} nssfixPurpleSslNssData;

static PurpleSslOps new_ops = { };
static void (*original_connectfunc)(PurpleSslConnection *gsc) = NULL;

void hooked_connectfunc(PurpleSslConnection *gsc)
{
	if (purple_debug_is_verbose())
		purple_debug_info(FLIST_NSSFIX_PLUGIN_ID, "Running hooked connectfunc\n");

	original_connectfunc(gsc);
	nssfixPurpleSslNssData *nss_data = gsc->private_data;

	if (purple_debug_is_verbose())
		purple_debug_info(FLIST_NSSFIX_PLUGIN_ID, "Setting Peer ID: %s\n", gsc->host);

	SSL_SetSockPeerID(nss_data->in, gsc->host);
}

static gboolean
plugin_load(PurplePlugin *plugin)
{
	if (strcmp(NSSSSL_GetVersion(), "3.23") >= 0)
	{
		purple_debug_info(FLIST_NSSFIX_PLUGIN_ID, "Doing nothing - NSS is version 3.23 or later\n");
		return TRUE;
	}

	PurpleSslOps *current_opts = purple_ssl_get_ops();

	if (!current_opts)
	{
		purple_debug_info(FLIST_NSSFIX_PLUGIN_ID, "Doing nothing - SSL operations were not set\n");
		return TRUE;
	}

	memcpy(&new_ops, current_opts, sizeof(PurpleSslOps));

	if (original_connectfunc != NULL || new_ops.connectfunc == hooked_connectfunc)
	{
		purple_debug_info(FLIST_NSSFIX_PLUGIN_ID, "Doing nothing - SSL operations were already hooked\n");
		return TRUE;
	}

	original_connectfunc = new_ops.connectfunc;
	new_ops.connectfunc = hooked_connectfunc;

	purple_debug_info(FLIST_NSSFIX_PLUGIN_ID, "Hooking SSL operations\n");
	purple_ssl_set_ops(&new_ops);

	return TRUE;
}

static gboolean
plugin_unload(PurplePlugin *plugin)
{
	if (original_connectfunc != NULL)
	{
		new_ops.connectfunc = original_connectfunc;

		purple_debug_info(FLIST_NSSFIX_PLUGIN_ID, "Un-hooking SSL operations\n");
		purple_ssl_set_ops(&new_ops);

		original_connectfunc = NULL;
	}

	return TRUE;
}

static PurplePluginInfo info =
{
	PURPLE_PLUGIN_MAGIC,
	PURPLE_MAJOR_VERSION,
	PURPLE_MINOR_VERSION,
	PURPLE_PLUGIN_STANDARD,                           /**< type           */
    NULL,                                             /**< ui_requirement */
	0,                                                /**< flags          */
	NULL,                                             /**< dependencies   */
	PURPLE_PRIORITY_HIGHEST,                          /**< priority       */
	FLIST_NSSFIX_PLUGIN_ID,                           /**< id             */
	"FList NSS Fix",                                  /**< name           */
	"1.0",                                            /**< version        */
	                                                  /**  summary        */
	"Hacky plugin to fix an issue with pre-3.23 versions of NSS",
	                                                  /**  description    */
	"Hacky plugin to fix an issue with pre-3.23 versions of NSS",
	"SyldraTheCat",
	"https://f-list.net/",                            /**< homepage       */

	plugin_load,                                      /**< load           */
	plugin_unload,                                    /**< unload         */
	NULL,                                             /**< destroy        */

	NULL,                                             /**< ui_info        */
	NULL,                                             /**< extra_info     */
	NULL,
	NULL,

	/* padding */
	NULL,
	NULL,
	NULL,
	NULL
};

static GList dependency_ssl_nss =
{
	"ssl-nss",
	NULL,
	NULL
};

static void
init_plugin(PurplePlugin *plugin)
{
	plugin->info->dependencies = &dependency_ssl_nss;
}

PURPLE_INIT_PLUGIN(flist_nssfix, init_plugin, info)