1/*
2 * Copyright (C) 2009, 2011  Internet Systems Consortium, Inc. ("ISC")
3 *
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
9 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
10 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
11 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
12 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
13 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
14 * PERFORMANCE OF THIS SOFTWARE.
15 */
16
17/* $Id: ddns-confgen.c,v 1.9.308.2 2011/03/12 04:59:13 tbox Exp $ */
18
19/*! \file */
20
21/**
22 * ddns-confgen generates configuration files for dynamic DNS. It can
23 * be used as a convenient alternative to writing the ddns.key file
24 * and the corresponding key and update-policy statements in named.conf.
25 */
26
27#include <config.h>
28
29#include <stdlib.h>
30#include <stdarg.h>
31
32#include <isc/assertions.h>
33#include <isc/base64.h>
34#include <isc/buffer.h>
35#include <isc/commandline.h>
36#include <isc/entropy.h>
37#include <isc/file.h>
38#include <isc/keyboard.h>
39#include <isc/mem.h>
40#include <isc/net.h>
41#include <isc/print.h>
42#include <isc/result.h>
43#include <isc/string.h>
44#include <isc/time.h>
45#include <isc/util.h>
46
47#include <dns/keyvalues.h>
48#include <dns/name.h>
49
50#include <dst/dst.h>
51#include <confgen/os.h>
52
53#include "util.h"
54#include "keygen.h"
55
56#define DEFAULT_KEYNAME		"ddns-key"
57
58static char program[256];
59const char *progname;
60
61isc_boolean_t verbose = ISC_FALSE;
62
63ISC_PLATFORM_NORETURN_PRE static void
64usage(int status) ISC_PLATFORM_NORETURN_POST;
65
66static void
67usage(int status) {
68
69	fprintf(stderr, "\
70Usage:\n\
71 %s [-a alg] [-k keyname] [-r randomfile] [-q] [-s name | -z zone]\n\
72  -a alg:        algorithm (default hmac-sha256)\n\
73  -k keyname:    name of the key as it will be used in named.conf\n\
74  -r randomfile: source of random data (use \"keyboard\" for key timing)\n\
75  -s name:       domain name to be updated using the created key\n\
76  -z zone:       name of the zone as it will be used in named.conf\n\
77  -q:            quiet mode: print the key, with no explanatory text\n",
78		 progname);
79
80	exit (status);
81}
82
83int
84main(int argc, char **argv) {
85	isc_boolean_t show_final_mem = ISC_FALSE;
86	isc_boolean_t quiet = ISC_FALSE;
87	isc_buffer_t key_txtbuffer;
88	char key_txtsecret[256];
89	isc_mem_t *mctx = NULL;
90	isc_result_t result = ISC_R_SUCCESS;
91	const char *randomfile = NULL;
92	const char *keyname = NULL;
93	const char *zone = NULL;
94	const char *self_domain = NULL;
95	char *keybuf = NULL;
96	dns_secalg_t alg = DST_ALG_HMACSHA256;
97	const char *algname = alg_totext(alg);
98	int keysize = 256;
99	int len = 0;
100	int ch;
101
102	result = isc_file_progname(*argv, program, sizeof(program));
103	if (result != ISC_R_SUCCESS)
104		memcpy(program, "ddns-confgen", 13);
105	progname = program;
106
107	isc_commandline_errprint = ISC_FALSE;
108
109	while ((ch = isc_commandline_parse(argc, argv,
110					   "a:hk:Mmr:qs:Vy:z:")) != -1) {
111		switch (ch) {
112		case 'a':
113			algname = isc_commandline_argument;
114			alg = alg_fromtext(algname);
115			if (alg == DST_ALG_UNKNOWN)
116				fatal("Unsupported algorithm '%s'", algname);
117			keysize = alg_bits(alg);
118			break;
119		case 'h':
120			usage(0);
121		case 'k':
122		case 'y':
123			keyname = isc_commandline_argument;
124			break;
125		case 'M':
126			isc_mem_debugging = ISC_MEM_DEBUGTRACE;
127			break;
128		case 'm':
129			show_final_mem = ISC_TRUE;
130			break;
131		case 'q':
132			quiet = ISC_TRUE;
133			break;
134		case 'r':
135			randomfile = isc_commandline_argument;
136			break;
137		case 's':
138			self_domain = isc_commandline_argument;
139			break;
140		case 'V':
141			verbose = ISC_TRUE;
142			break;
143		case 'z':
144			zone = isc_commandline_argument;
145			break;
146		case '?':
147			if (isc_commandline_option != '?') {
148				fprintf(stderr, "%s: invalid argument -%c\n",
149					program, isc_commandline_option);
150				usage(1);
151			} else
152				usage(0);
153			break;
154		default:
155			fprintf(stderr, "%s: unhandled option -%c\n",
156				program, isc_commandline_option);
157			exit(1);
158		}
159	}
160
161	argc -= isc_commandline_index;
162	argv += isc_commandline_index;
163	POST(argv);
164
165	if (self_domain != NULL && zone != NULL)
166		usage(1);	/* -s and -z cannot coexist */
167
168	if (argc > 0)
169		usage(1);
170
171	DO("create memory context", isc_mem_create(0, 0, &mctx));
172
173	if (keyname == NULL) {
174		const char *suffix = NULL;
175
176		keyname = DEFAULT_KEYNAME;
177		if (self_domain != NULL)
178			suffix = self_domain;
179		else if (zone != NULL)
180			suffix = zone;
181		if (suffix != NULL) {
182			len = strlen(keyname) + strlen(suffix) + 2;
183			keybuf = isc_mem_get(mctx, len);
184			if (keybuf == NULL)
185				fatal("failed to allocate memory for keyname");
186			snprintf(keybuf, len, "%s.%s", keyname, suffix);
187			keyname = (const char *) keybuf;
188		}
189	}
190
191	isc_buffer_init(&key_txtbuffer, &key_txtsecret, sizeof(key_txtsecret));
192
193	generate_key(mctx, randomfile, alg, keysize, &key_txtbuffer);
194
195
196	if (!quiet)
197		printf("\
198# To activate this key, place the following in named.conf, and\n\
199# in a separate keyfile on the system or systems from which nsupdate\n\
200# will be run:\n");
201
202	printf("\
203key \"%s\" {\n\
204	algorithm %s;\n\
205	secret \"%.*s\";\n\
206};\n",
207	       keyname, algname,
208	       (int)isc_buffer_usedlength(&key_txtbuffer),
209	       (char *)isc_buffer_base(&key_txtbuffer));
210
211	if (!quiet) {
212		if (self_domain != NULL) {
213			printf("\n\
214# Then, in the \"zone\" statement for the zone containing the\n\
215# name \"%s\", place an \"update-policy\" statement\n\
216# like this one, adjusted as needed for your preferred permissions:\n\
217update-policy {\n\
218	  grant %s name %s ANY;\n\
219};\n",
220			       self_domain, keyname, self_domain);
221		} else if (zone != NULL) {
222			printf("\n\
223# Then, in the \"zone\" definition statement for \"%s\",\n\
224# place an \"update-policy\" statement like this one, adjusted as \n\
225# needed for your preferred permissions:\n\
226update-policy {\n\
227	  grant %s zonesub ANY;\n\
228};\n",
229			       zone, keyname);
230		} else {
231			printf("\n\
232# Then, in the \"zone\" statement for each zone you wish to dynamically\n\
233# update, place an \"update-policy\" statement granting update permission\n\
234# to this key.  For example, the following statement grants this key\n\
235# permission to update any name within the zone:\n\
236update-policy {\n\
237	grant %s zonesub ANY;\n\
238};\n",
239			       keyname);
240		}
241
242		printf("\n\
243# After the keyfile has been placed, the following command will\n\
244# execute nsupdate using this key:\n\
245nsupdate -k <keyfile>\n");
246
247	}
248
249	if (keybuf != NULL)
250		isc_mem_put(mctx, keybuf, len);
251
252	if (show_final_mem)
253		isc_mem_stats(mctx, stderr);
254
255	isc_mem_destroy(&mctx);
256
257	return (0);
258}
259