Simple command-line interface to GNOME keyring

gnome-keyring-query.c

/*
 * gnome-keyring-query, for simple command-line interactions with gnome-keyring.
 *
 * To compile and install:
 *
 * sudo apt-get install libgnome-keyring-dev libglib2.0-dev
 * gcc `pkg-config --cflags --libs gnome-keyring-1 glib-2.0` -o gnome-keyring-query gnome-keyring-query.c
 * chmod +x gnome-keyring-query
 * sudo cp -p gnome-keyring-query /usr/local/bin/
 *
 * Forked from public domain code by author(s) unknown, archived at
 * https://web.archive.org/web/20160326164519/http://www.gentoo-wiki.info/Store_SSH_passphrases_in_gnome-keyring
 *
 * All changes from the original source are Copyright 2014+ Adam Katz
 * and are released under the GNU LGPL.
 *
 * 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) any later version.
 *
 * 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.
 *
 * See <http://www.gnu.org/licenses/> for full license text.
 *
 * BEERWARE: IF YOU THINK THIS IS WORTH IT, YOU ARE WELCOME TO BUY ME A BEER.
 */

#include <stdlib.h>
#include <stdio.h>

#include <glib.h>

/*
 * Workaround for deprecation of libgnome-keyring (won't work forever)
 * TODO: migrate to libsecret (which looks nontrivial, likely WONTFIX).
 * Notes for that:
 *     https://codereview.chromium.org/292573002
 *     https://bugs.chromium.org/p/chromium/issues/detail?id=355223
 */
#define GNOME_KEYRING_DEPRECATED
#define GNOME_KEYRING_DEPRECATED_FOR(x)

#include "gnome-keyring.h"


#define APPLICATION_NAME "gnome-keyring-query"
#define VERSION "1.2.20190212"
#define MAX_PASSWORD_LENGTH 100

char * get_password(const char * name);
int    set_password(const char * name, const char * password);


void usage()
{
    puts("Usage:\n"
         "    " APPLICATION_NAME " <mode> <name>\n"
         "Parameters:\n"
         "    mode     - either 'get' or 'set' (without quotes)\n"
         "    name     - a name to identify the key\n"
         "Notes:\n"
         "    If mode is 'get', then the password is dumped to stdout.\n"
         "    If mode is 'set', then the password is read from stdin.\n"
         "\nVersion: " VERSION "\n"
         "https://gist.github.com/adamhotep/e5798989187b393789c1"
         );
    exit(EXIT_FAILURE);
}


int main(int argc, char * argv[])
{
    enum
    {
        MODE_GET, MODE_SET
    } mode;
    char * name;
    char * password;
    
    g_set_application_name(APPLICATION_NAME);
    
    if (argc != 3)
        usage();
        
    if (g_ascii_strcasecmp(argv[1], "get") == 0)
        mode = MODE_GET;
    else if (g_ascii_strcasecmp(argv[1], "set") == 0)
        mode = MODE_SET;
    else
    {
        fprintf(stderr, "Invalid mode: %s\n", argv[1]);
        exit(EXIT_FAILURE);
    }
    
    name = argv[2];
    
    switch (mode)
    {
        case MODE_GET:
            password = get_password(name);
            if (!password)
            {
                fprintf(stderr, "Failed to get password: %s\n", name);
                exit(EXIT_FAILURE);
            }
            
            puts(password);
            g_free(password);
            break;
            
        case MODE_SET:
            password = g_malloc(MAX_PASSWORD_LENGTH);
            *password = '\0';
            fgets(password, MAX_PASSWORD_LENGTH, stdin);
            
            if (!set_password(name, password))
            {
                fprintf(stderr, "Failed to set password: %s\n", name);
                exit(EXIT_FAILURE);
            }
            
            g_free(password);
            break;
    }
    
    return 0;
}


char * get_password(const char * name)
{
    GnomeKeyringAttributeList * attributes;
    GnomeKeyringResult result;
    GList * found_list;
    GList * i;
    GnomeKeyringFound * found;
    char * password;
    
    attributes = g_array_new(FALSE, FALSE, sizeof (GnomeKeyringAttribute));
    gnome_keyring_attribute_list_append_string(attributes,
            "name",
            name);
    gnome_keyring_attribute_list_append_string(attributes,
            "magic",
            APPLICATION_NAME);
    
    result = gnome_keyring_find_items_sync(GNOME_KEYRING_ITEM_GENERIC_SECRET,
            attributes,
            &found_list);
    gnome_keyring_attribute_list_free(attributes);
    
    if (result != GNOME_KEYRING_RESULT_OK)
        return NULL;
    
    for (i = found_list; i != NULL; i = i->next)
    {
        found = i->data;
        password = g_strdup(found->secret);
        break;
    }
    gnome_keyring_found_list_free(found_list);
    
    return password;
}


int set_password(const char * name, const char * password)
{
    GnomeKeyringAttributeList * attributes;
    GnomeKeyringResult result;
    guint item_id;
    
    attributes = g_array_new(FALSE, FALSE, sizeof (GnomeKeyringAttribute));
    gnome_keyring_attribute_list_append_string(attributes,
            "name",
            name);
    gnome_keyring_attribute_list_append_string(attributes,
            "magic",
            APPLICATION_NAME);
    
    result = gnome_keyring_item_create_sync(NULL,
            GNOME_KEYRING_ITEM_GENERIC_SECRET,
            name,
            attributes,
            password,
            TRUE,
            &item_id);
    gnome_keyring_attribute_list_free(attributes);
    
    return (result == GNOME_KEYRING_RESULT_OK);
}

@qrkourier – Sorry, I must have missed the github notification for that comment.

Looks like the guts of GNOME keyring are slated for removal. This code depends on deprecated methods and GNOME 3.12+ didn't want to let it happen without an explicit workaround. Solved, at least until "deprecated" becomes "obsoleted."