nbsvtool.c revision 1.4 
1/*	$NetBSD: nbsvtool.c,v 1.4 2018/02/06 20:15:39 christos Exp $	*/
2
3/*-
4 * Copyright (c) 2004, 2008 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Love H�rnquist �strand <lha@it.su.se>
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#include <err.h>
33#include <stdio.h>
34#include <stdlib.h>
35#include <string.h>
36#include <unistd.h>
37
38#include <openssl/pkcs7.h>
39#include <openssl/evp.h>
40#include <openssl/x509.h>
41#include <openssl/x509v3.h>
42#include <openssl/pem.h>
43#include <openssl/err.h>
44#include <openssl/ui.h>
45
46static int verbose_flag;
47static unsigned long key_usage = 0;
48
49/*
50 * openssl command line equivalents
51 *
52 *    openssl smime -verify \
53 *		-inform PEM -in nbsvtool.c.sig -content nbsvtool.c \
54 *		-CAfile /secure/lha/su/CA/swupki-pca.crt -out /dev/null
55 *    openssl smime -sign \
56 *		-noattr -binary -outform PEM -out nbsvtool.c.sig \
57 *		-in nbsvtool.c -signer /secure/lha/su/CA/lha.crt \
58 *		-certfile /secure/lha/su/CA/lha-chain \
59 *		-inkey /secure/lha/su/CA/lha.key
60 */
61
62/*
63 * Create a detach PEM signature of file `infile' and store it in
64 * `outfile'. The signer certificate `cert' and private key
65 * `private_key' must be given. An additional hint to the verifier how
66 * to find the path from the `cert' to the x509 anchor can be passed
67 * in `cert_chain'.
68 */
69
70static void
71sign_file(X509 *cert, EVP_PKEY *private_key, STACK_OF(X509) *cert_chain,
72	  const char *infile, const char *outfile)
73{
74	BIO *out, *in;
75	PKCS7 *p7;
76
77	out = BIO_new_file(outfile, "w");
78	if (out == NULL)
79		err(EXIT_FAILURE, "Failed to open signature output file: %s",
80		    outfile);
81
82	in = BIO_new_file(infile, "r");
83	if (in == NULL)
84		err(EXIT_FAILURE, "Failed to input file: %s", infile);
85
86	p7 = PKCS7_sign(cert, private_key, cert_chain, in,
87	    PKCS7_DETACHED|PKCS7_NOATTR|PKCS7_BINARY);
88	if (p7 == NULL)
89		errx(EXIT_FAILURE, "Failed to create signature structure");
90
91	PEM_write_bio_PKCS7(out, p7);
92
93	PKCS7_free(p7);
94	BIO_free(in);
95	BIO_free_all(out);
96}
97
98/*
99 * Verifies a detached PEM signature in the file `sigfile' of file
100 * `infile'. The trust anchor file `anchor' to the trust anchors must
101 * be given. If its suspended that the sender didn't inlude the whole
102 * path from the signing certificate to the given trust anchor, extra
103 * certificates can be passed in `cert_chain'.
104 */
105
106static void
107verify_file(STACK_OF(X509) *cert_chain, const char *anchor,
108	    const char *infile, const char *sigfile)
109{
110	STACK_OF(X509) *signers;
111	X509_STORE *store;
112	BIO *sig, *in;
113	PKCS7 *p7;
114	int ret, i;
115	X509_NAME *name;
116	char *subject;
117
118	store = X509_STORE_new();
119	if (store == NULL)
120		err(1, "Failed to create store");
121
122	X509_STORE_load_locations(store, anchor, NULL);
123
124	in = BIO_new_file(infile, "r");
125	if (in == NULL)
126		err(EXIT_FAILURE, "Failed to open input data file: %s", infile);
127
128	sig = BIO_new_file(sigfile, "r");
129	if (sig == NULL)
130		err(EXIT_FAILURE, "Failed to open signature input file: %s",
131		    sigfile);
132
133	p7 = PEM_read_bio_PKCS7(sig, NULL, NULL, NULL);
134	if (p7 == NULL)
135		errx(EXIT_FAILURE, "Failed to parse the signature file %s",
136		    sigfile);
137
138	ret = PKCS7_verify(p7, cert_chain, store, in, NULL, 0);
139	if (ret != 1)
140		errx(EXIT_FAILURE, "Failed to verify signature");
141
142	signers = PKCS7_get0_signers(p7, NULL, 0);
143	if (signers == NULL)
144		errx(EXIT_FAILURE, "Failed to get signers");
145
146	if (sk_X509_num(signers) == 0)
147		errx(EXIT_FAILURE, "No signers ?");
148
149	if (key_usage != 0) {
150		for (i = 0; i < sk_X509_num(signers); i++) {
151			X509 *x = sk_X509_value(signers, i);
152			if ((X509_get_extended_key_usage(x) & key_usage)
153			    == key_usage)
154				continue;
155			name = X509_get_subject_name(x);
156			subject = X509_NAME_oneline(name, NULL, 0);
157			errx(EXIT_FAILURE,
158			    "Certificate doesn't match required key usage: %s",
159			    subject);
160		}
161	}
162
163	if (verbose_flag)
164		printf("Sigature ok, signed by:\n");
165
166	for (i = 0; i < sk_X509_num(signers); i++) {
167		name = X509_get_subject_name(sk_X509_value(signers, i));
168		subject = X509_NAME_oneline(name, NULL, 0);
169
170		if (verbose_flag)
171			printf("\t%s\n", subject);
172
173		OPENSSL_free(subject);
174	}
175
176	PKCS7_free(p7);
177	BIO_free(in);
178	BIO_free(sig);
179}
180
181/*
182 * Parse and return a list PEM encoded certificates in the file
183 * `file'. In case of error or an empty file, and error text will be
184 * printed and the function will exit(3).
185 */
186
187static STACK_OF(X509) *
188file_to_certs(const char *file)
189{
190	STACK_OF(X509) *certs;
191	FILE *f;
192
193	f = fopen(file, "r");
194	if (f == NULL)
195		err(EXIT_FAILURE, "Cannot open certificate file %s", file);
196	certs = sk_X509_new_null();
197	while (1) {
198		X509 *cert;
199
200		cert = PEM_read_X509(f, NULL, NULL, NULL);
201		if (cert == NULL) {
202			unsigned long ret;
203
204			ret = ERR_GET_REASON(ERR_peek_error());
205			if (ret == PEM_R_NO_START_LINE) {
206				/* End of file reached. no error */
207				ERR_clear_error();
208				break;
209			}
210			errx(EXIT_FAILURE, "Can't read certificate file %s",
211			    file);
212		}
213		sk_X509_insert(certs, cert, sk_X509_num(certs));
214	}
215	fclose(f);
216	if (sk_X509_num(certs) == 0)
217		errx(EXIT_FAILURE, "No certificate found file %s", file);
218
219	return certs;
220}
221
222static int
223ssl_pass_cb(char *buf, int size, int rwflag, void *u)
224{
225
226	if (UI_UTIL_read_pw_string(buf, size, "Passphrase: ", 0))
227		return 0;
228	return strlen(buf);
229}
230
231static struct {
232	X509 *certificate;
233	STACK_OF(X509) *cert_chain;
234	EVP_PKEY *private_key;
235} crypto_state;
236
237/*
238 * Load the certificate file `cert_file' with the associated private
239 * key file `key_file'. The private key is checked to make sure it
240 * matches the certificate. The optional hints for the path to the CA
241 * is stored in `chain_file'.
242 */
243
244static void
245load_keys(const char *cert_file, const char *chain_file, const char *key_file)
246{
247	STACK_OF(X509) *c;
248	FILE *f;
249	int ret;
250
251	if (cert_file == NULL)
252		errx(EXIT_FAILURE, "No certificate file given");
253	if (key_file == NULL)
254		errx(EXIT_FAILURE, "No private key file given");
255
256	c = file_to_certs(cert_file);
257
258	if (sk_X509_num(c) != 1)
259		errx(EXIT_FAILURE,
260		    "More then one certificate in the certificate file");
261	crypto_state.certificate = sk_X509_value(c, 0);
262
263	if (chain_file)
264		crypto_state.cert_chain = file_to_certs(chain_file);
265
266	/* load private key */
267	f = fopen(key_file, "r");
268	if (f == NULL)
269		errx(1, "Failed to open private key file %s", key_file);
270
271	crypto_state.private_key =
272		PEM_read_PrivateKey(f, NULL, ssl_pass_cb, NULL);
273	fclose(f);
274	if (crypto_state.private_key == NULL)
275		errx(EXIT_FAILURE, "Can't read private key %s", key_file);
276
277	ret = X509_check_private_key(crypto_state.certificate,
278	    crypto_state.private_key);
279	if (ret != 1)
280		errx(EXIT_FAILURE,
281		    "The private key %s doesn't match the certificate %s",
282		    key_file, cert_file);
283}
284
285static void __dead
286usage(int exit_code)
287{
288
289	printf("%s usage\n", getprogname());
290	printf("%s -k keyfile -c cert-chain [-f cert-chain] sign file\n",
291	    getprogname());
292	printf("%s [-u code|...] [-a x509-anchor-file] verify filename.sp7\n",
293	    getprogname());
294	printf("%s [-u code|...] [-a x509-anchor-file] verify filename otherfilename.sp7\n",
295	    getprogname());
296	printf("%s [-u code|...] [-a x509-anchor-file] verify-code file ...\n",
297	    getprogname());
298	exit(exit_code);
299}
300
301int
302main(int argc, char **argv)
303{
304	const char *anchors = NULL;
305	const char *cert_file = NULL, *key_file = NULL, *chain_file = NULL;
306	const char *file;
307	char *sigfile;
308	int ch;
309
310	setprogname(argv[0]);
311
312#if OPENSSL_VERSION_NUMBER < 0x10100000L
313	OpenSSL_add_all_algorithms();
314	ERR_load_crypto_strings();
315#endif
316
317	while ((ch = getopt(argc, argv, "a:c:f:hk:u:v")) != -1) {
318		switch (ch) {
319		case 'a':
320			anchors = optarg;
321			break;
322		case 'f':
323			chain_file = optarg;
324			break;
325		case 'k':
326			key_file = optarg;
327			break;
328		case 'c':
329			cert_file = optarg;
330			break;
331		case 'u':
332			if (strcmp("ssl-server", optarg) == 0)
333				key_usage |= XKU_SSL_SERVER;
334			else if (strcmp("ssl-client", optarg) == 0)
335				key_usage |= XKU_SSL_CLIENT;
336			else if (strcmp("code", optarg) == 0)
337				key_usage |= XKU_CODE_SIGN;
338			else if (strcmp("smime", optarg) == 0)
339				key_usage |= XKU_SMIME;
340			else
341				errx(1, "Unknown keyusage: %s", optarg);
342			break;
343		case 'v':
344			verbose_flag = 1;
345			break;
346		case 'h':
347			usage(EXIT_SUCCESS);
348		default:
349			usage(EXIT_FAILURE);
350		}
351	}
352
353	argc -= optind;
354	argv += optind;
355
356	if (argc < 1) {
357		fprintf(stderr, "Command missing [sign|verify]\n");
358		usage(EXIT_FAILURE);
359	}
360
361	if (strcmp(argv[0], "sign") == 0) {
362
363		if (argc < 2)
364			usage(1);
365
366		file = argv[1];
367
368		asprintf(&sigfile, "%s.sp7", file);
369		if (sigfile == NULL)
370			err(EXIT_FAILURE, "asprintf failed");
371
372		load_keys(cert_file, chain_file, key_file);
373
374		sign_file(crypto_state.certificate,
375		    crypto_state.private_key,
376		    crypto_state.cert_chain,
377		    file,
378		    sigfile);
379
380	} else if (strcmp(argv[0], "verify") == 0
381	    || strcmp(argv[0], "verify-code") == 0) {
382
383		if (strcmp(argv[0], "verify-code") == 0)
384			key_usage |= XKU_CODE_SIGN;
385
386		if (argc < 2)
387			usage(1);
388		else if (argc < 3) {
389			char *dot;
390
391			sigfile = argv[1];
392
393			file = strdup(sigfile);
394			if (file == NULL)
395				err(1, "strdup failed");
396
397			dot = strrchr(file, '.');
398			if (dot == NULL || strchr(dot, '/') != NULL)
399				errx(EXIT_FAILURE,
400				    "File name missing suffix");
401			if (strcmp(".sp7", dot) != 0)
402				errx(EXIT_FAILURE,
403				    "File name bad suffix (%s)", dot);
404			*dot = '\0';
405		} else {
406			file = argv[1];
407			sigfile = argv[2];
408		}
409		verify_file(crypto_state.cert_chain, anchors, file, sigfile);
410	} else {
411		fprintf(stderr, "Unknown command: %s\n", argv[0]);
412		usage(EXIT_FAILURE);
413	}
414
415	return 0;
416}
417