bin/confgen/ddns-confgen.c

	ddns-confgen.c revision c1aef54e14bb92518b1c062ba8c0292a7cb949cb
/*
 * Copyright (C) 2009, 2011  Internet Systems Consortium, Inc. ("ISC")
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: ddns-confgen.c,v 1.11 2011/03/12 04:59:46 tbox Exp $ */

/*! \file */

/**
 * ddns-confgen generates configuration files for dynamic DNS. It can
 * be used as a convenient alternative to writing the ddns.key file
 * and the corresponding key and update-policy statements in named.conf.
 */

#include <config.h>

#include <stdlib.h>
#include <stdarg.h>

#include <isc/assertions.h>
#include <isc/base64.h>
#include <isc/buffer.h>
#include <isc/commandline.h>
#include <isc/entropy.h>
#include <isc/file.h>
#include <isc/keyboard.h>
#include <isc/mem.h>
#include <isc/net.h>
#include <isc/print.h>
#include <isc/result.h>
#include <isc/string.h>
#include <isc/time.h>
#include <isc/util.h>

#include <dns/keyvalues.h>
#include <dns/name.h>

#include <dst/dst.h>
#include <confgen/os.h>

#include "util.h"
#include "keygen.h"

#define DEFAULT_KEYNAME     "ddns-key"

static char program[256];
const char *progname;

isc_boolean_t verbose = ISC_FALSE;

ISC_PLATFORM_NORETURN_PRE static void
usage(int status) ISC_PLATFORM_NORETURN_POST;

static void
usage(int status) {

    fprintf(stderr, "\
Usage:\n\
 %s [-a alg] [-k keyname] [-r randomfile] [-q] [-s name | -z zone]\n\
  -a alg:        algorithm (default hmac-sha256)\n\
  -k keyname:    name of the key as it will be used in named.conf\n\
  -r randomfile: source of random data (use \"keyboard\" for key timing)\n\
  -s name:       domain name to be updated using the created key\n\
  -z zone:       name of the zone as it will be used in named.conf\n\
  -q:            quiet mode: print the key, with no explanatory text\n",
         progname);

    exit (status);
}

int
main(int argc, char **argv) {
    isc_boolean_t show_final_mem = ISC_FALSE;
    isc_boolean_t quiet = ISC_FALSE;
    isc_buffer_t key_txtbuffer;
    char key_txtsecret[256];
    isc_mem_t *mctx = NULL;
    isc_result_t result = ISC_R_SUCCESS;
    const char *randomfile = NULL;
    const char *keyname = NULL;
    const char *zone = NULL;
    const char *self_domain = NULL;
    char *keybuf = NULL;
    dns_secalg_t alg = DST_ALG_HMACSHA256;
    const char *algname = alg_totext(alg);
    int keysize = 256;
    int len = 0;
    int ch;

    result = isc_file_progname(*argv, program, sizeof(program));
    if (result != ISC_R_SUCCESS)
        memcpy(program, "ddns-confgen", 13);
    progname = program;

    isc_commandline_errprint = ISC_FALSE;

    while ((ch = isc_commandline_parse(argc, argv,
                       "a:hk:Mmr:qs:Vy:z:")) != -1) {
        switch (ch) {
        case 'a':
            algname = isc_commandline_argument;
            alg = alg_fromtext(algname);
            if (alg == DST_ALG_UNKNOWN)
                fatal("Unsupported algorithm '%s'", algname);
            keysize = alg_bits(alg);
            break;
        case 'h':
            usage(0);
        case 'k':
        case 'y':
            keyname = isc_commandline_argument;
            break;
        case 'M':
            isc_mem_debugging = ISC_MEM_DEBUGTRACE;
            break;
        case 'm':
            show_final_mem = ISC_TRUE;
            break;
        case 'q':
            quiet = ISC_TRUE;
            break;
        case 'r':
            randomfile = isc_commandline_argument;
            break;
        case 's':
            self_domain = isc_commandline_argument;
            break;
        case 'V':
            verbose = ISC_TRUE;
            break;
        case 'z':
            zone = isc_commandline_argument;
            break;
        case '?':
            if (isc_commandline_option != '?') {
                fprintf(stderr, "%s: invalid argument -%c\n",
                    program, isc_commandline_option);
                usage(1);
            } else
                usage(0);
            break;
        default:
            fprintf(stderr, "%s: unhandled option -%c\n",
                program, isc_commandline_option);
            exit(1);
        }
    }

    argc -= isc_commandline_index;
    argv += isc_commandline_index;
    POST(argv);

    if (self_domain != NULL && zone != NULL)
        usage(1);   /* -s and -z cannot coexist */

    if (argc > 0)
        usage(1);

    DO("create memory context", isc_mem_create(0, 0, &mctx));

    if (keyname == NULL) {
        const char *suffix = NULL;

        keyname = DEFAULT_KEYNAME;
        if (self_domain != NULL)
            suffix = self_domain;
        else if (zone != NULL)
            suffix = zone;
        if (suffix != NULL) {
            len = strlen(keyname) + strlen(suffix) + 2;
            keybuf = isc_mem_get(mctx, len);
            if (keybuf == NULL)
                fatal("failed to allocate memory for keyname");
            snprintf(keybuf, len, "%s.%s", keyname, suffix);
            keyname = (const char *) keybuf;
        }
    }

    isc_buffer_init(&key_txtbuffer, &key_txtsecret, sizeof(key_txtsecret));

    generate_key(mctx, randomfile, alg, keysize, &key_txtbuffer);


    if (!quiet)
        printf("\
# To activate this key, place the following in named.conf, and\n\
# in a separate keyfile on the system or systems from which nsupdate\n\
# will be run:\n");

    printf("\
key \"%s\" {\n\
    algorithm %s;\n\
    secret \"%.*s\";\n\
};\n",
           keyname, algname,
           (int)isc_buffer_usedlength(&key_txtbuffer),
           (char *)isc_buffer_base(&key_txtbuffer));

    if (!quiet) {
        if (self_domain != NULL) {
            printf("\n\
# Then, in the \"zone\" statement for the zone containing the\n\
# name \"%s\", place an \"update-policy\" statement\n\
# like this one, adjusted as needed for your preferred permissions:\n\
update-policy {\n\
      grant %s name %s ANY;\n\
};\n",
                   self_domain, keyname, self_domain);
        } else if (zone != NULL) {
            printf("\n\
# Then, in the \"zone\" definition statement for \"%s\",\n\
# place an \"update-policy\" statement like this one, adjusted as \n\
# needed for your preferred permissions:\n\
update-policy {\n\
      grant %s zonesub ANY;\n\
};\n",
                   zone, keyname);
        } else {
            printf("\n\
# Then, in the \"zone\" statement for each zone you wish to dynamically\n\
# update, place an \"update-policy\" statement granting update permission\n\
# to this key.  For example, the following statement grants this key\n\
# permission to update any name within the zone:\n\
update-policy {\n\
    grant %s zonesub ANY;\n\
};\n",
                   keyname);
        }

        printf("\n\
# After the keyfile has been placed, the following command will\n\
# execute nsupdate using this key:\n\
nsupdate -k <keyfile>\n");

    }

    if (keybuf != NULL)
        isc_mem_put(mctx, keybuf, len);

    if (show_final_mem)
        isc_mem_stats(mctx, stderr);

    isc_mem_destroy(&mctx);

    return (0);
}