1 /* Sign a module file using the given key.
3 * Copyright © 2014-2016 Red Hat, Inc. All Rights Reserved.
4 * Copyright © 2015 Intel Corporation.
5 * Copyright © 2016 Hewlett Packard Enterprise Development LP
7 * Authors: David Howells <dhowells@redhat.com>
8 * David Woodhouse <dwmw2@infradead.org>
9 * Juerg Haefliger <juerg.haefliger@hpe.com>
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Lesser General Public License
13 * as published by the Free Software Foundation; either version 2.1
14 * of the licence, or (at your option) any later version.
24 #include <arpa/inet.h>
25 #include <openssl/opensslv.h>
26 #include <openssl/bio.h>
27 #include <openssl/evp.h>
28 #include <openssl/pem.h>
29 #include <openssl/err.h>
30 #include <openssl/engine.h>
33 * OpenSSL 3.0 deprecates the OpenSSL's ENGINE API.
35 * Remove this if/when that API is no longer used
37 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
40 * Use CMS if we have openssl-1.0.0 or newer available - otherwise we have to
41 * assume that it's not available and its header file is missing and that we
42 * should use PKCS#7 instead. Switching to the older PKCS#7 format restricts
43 * the options we have on specifying the X.509 certificate we want.
45 * Further, older versions of OpenSSL don't support manually adding signers to
46 * the PKCS#7 message so have to accept that we get a certificate included in
47 * the signature message. Nor do such older versions of OpenSSL support
48 * signing with anything other than SHA1 - so we're stuck with that if such is
51 #if defined(LIBRESSL_VERSION_NUMBER) || \
52 OPENSSL_VERSION_NUMBER < 0x10000000L || \
53 defined(OPENSSL_NO_CMS)
57 #include <openssl/cms.h>
59 #include <openssl/pkcs7.h>
62 struct module_signature {
63 uint8_t algo; /* Public-key crypto algorithm [0] */
64 uint8_t hash; /* Digest algorithm [0] */
65 uint8_t id_type; /* Key identifier type [PKEY_ID_PKCS7] */
66 uint8_t signer_len; /* Length of signer's name [0] */
67 uint8_t key_id_len; /* Length of key identifier [0] */
69 uint32_t sig_len; /* Length of signature data */
72 #define PKEY_ID_PKCS7 2
74 static char magic_number[] = "~Module signature appended~\n";
76 static __attribute__((noreturn))
80 "Usage: scripts/sign-file [-dp] <hash algo> <key> <x509> <module> [<dest>]\n");
82 " scripts/sign-file -s <raw sig> <hash algo> <x509> <module> [<dest>]\n");
86 static void display_openssl_errors(int l)
92 if (ERR_peek_error() == 0)
94 fprintf(stderr, "At main.c:%d:\n", l);
96 while ((e = ERR_get_error_line(&file, &line))) {
97 ERR_error_string(e, buf);
98 fprintf(stderr, "- SSL %s: %s:%d\n", buf, file, line);
102 static void drain_openssl_errors(void)
107 if (ERR_peek_error() == 0)
109 while (ERR_get_error_line(&file, &line)) {}
112 #define ERR(cond, fmt, ...) \
114 bool __cond = (cond); \
115 display_openssl_errors(__LINE__); \
117 errx(1, fmt, ## __VA_ARGS__); \
121 static const char *key_pass;
123 static int pem_pw_cb(char *buf, int len, int w, void *v)
130 pwlen = strlen(key_pass);
134 strcpy(buf, key_pass);
136 /* If it's wrong, don't keep trying it. */
142 static EVP_PKEY *read_private_key(const char *private_key_name)
144 EVP_PKEY *private_key;
146 if (!strncmp(private_key_name, "pkcs11:", 7)) {
149 ENGINE_load_builtin_engines();
150 drain_openssl_errors();
151 e = ENGINE_by_id("pkcs11");
152 ERR(!e, "Load PKCS#11 ENGINE");
154 drain_openssl_errors();
156 ERR(1, "ENGINE_init");
158 ERR(!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0),
160 private_key = ENGINE_load_private_key(e, private_key_name,
162 ERR(!private_key, "%s", private_key_name);
166 b = BIO_new_file(private_key_name, "rb");
167 ERR(!b, "%s", private_key_name);
168 private_key = PEM_read_bio_PrivateKey(b, NULL, pem_pw_cb,
170 ERR(!private_key, "%s", private_key_name);
177 static X509 *read_x509(const char *x509_name)
179 unsigned char buf[2];
184 b = BIO_new_file(x509_name, "rb");
185 ERR(!b, "%s", x509_name);
187 /* Look at the first two bytes of the file to determine the encoding */
188 n = BIO_read(b, buf, 2);
190 if (BIO_should_retry(b)) {
191 fprintf(stderr, "%s: Read wanted retry\n", x509_name);
195 fprintf(stderr, "%s: Short read\n", x509_name);
198 ERR(1, "%s", x509_name);
201 ERR(BIO_reset(b) != 0, "%s", x509_name);
203 if (buf[0] == 0x30 && buf[1] >= 0x81 && buf[1] <= 0x84)
204 /* Assume raw DER encoded X.509 */
205 x509 = d2i_X509_bio(b, NULL);
207 /* Assume PEM encoded X.509 */
208 x509 = PEM_read_bio_X509(b, NULL, NULL, NULL);
211 ERR(!x509, "%s", x509_name);
216 int main(int argc, char **argv)
218 struct module_signature sig_info = { .id_type = PKEY_ID_PKCS7 };
219 char *hash_algo = NULL;
220 char *private_key_name = NULL, *raw_sig_name = NULL;
221 char *x509_name, *module_name, *dest_name;
222 bool save_sig = false, replace_orig;
223 bool sign_only = false;
224 bool raw_sig = false;
225 unsigned char buf[4096];
226 unsigned long module_size, sig_size;
227 unsigned int use_signed_attrs;
228 const EVP_MD *digest_algo;
229 EVP_PKEY *private_key;
231 CMS_ContentInfo *cms = NULL;
232 unsigned int use_keyid = 0;
239 OpenSSL_add_all_algorithms();
240 ERR_load_crypto_strings();
243 key_pass = getenv("KBUILD_SIGN_PIN");
246 use_signed_attrs = CMS_NOATTR;
248 use_signed_attrs = PKCS7_NOATTR;
252 opt = getopt(argc, argv, "sdpk");
254 case 's': raw_sig = true; break;
255 case 'p': save_sig = true; break;
256 case 'd': sign_only = true; save_sig = true; break;
258 case 'k': use_keyid = CMS_USE_KEYID; break;
267 if (argc < 4 || argc > 5)
271 raw_sig_name = argv[0];
275 private_key_name = argv[1];
278 module_name = argv[3];
279 if (argc == 5 && strcmp(argv[3], argv[4]) != 0) {
281 replace_orig = false;
283 ERR(asprintf(&dest_name, "%s.~signed~", module_name) < 0,
289 if (strcmp(hash_algo, "sha1") != 0) {
290 fprintf(stderr, "sign-file: %s only supports SHA1 signing\n",
291 OPENSSL_VERSION_TEXT);
296 /* Open the module file */
297 bm = BIO_new_file(module_name, "rb");
298 ERR(!bm, "%s", module_name);
301 /* Read the private key and the X.509 cert the PKCS#7 message
304 private_key = read_private_key(private_key_name);
305 x509 = read_x509(x509_name);
307 /* Digest the module data. */
308 OpenSSL_add_all_digests();
309 display_openssl_errors(__LINE__);
310 digest_algo = EVP_get_digestbyname(hash_algo);
311 ERR(!digest_algo, "EVP_get_digestbyname");
314 /* Load the signature message from the digest buffer. */
315 cms = CMS_sign(NULL, NULL, NULL, NULL,
316 CMS_NOCERTS | CMS_PARTIAL | CMS_BINARY |
317 CMS_DETACHED | CMS_STREAM);
318 ERR(!cms, "CMS_sign");
320 ERR(!CMS_add1_signer(cms, x509, private_key, digest_algo,
321 CMS_NOCERTS | CMS_BINARY |
322 CMS_NOSMIMECAP | use_keyid |
325 ERR(CMS_final(cms, bm, NULL, CMS_NOCERTS | CMS_BINARY) < 0,
329 pkcs7 = PKCS7_sign(x509, private_key, NULL, bm,
330 PKCS7_NOCERTS | PKCS7_BINARY |
331 PKCS7_DETACHED | use_signed_attrs);
332 ERR(!pkcs7, "PKCS7_sign");
339 ERR(asprintf(&sig_file_name, "%s.p7s", module_name) < 0,
341 b = BIO_new_file(sig_file_name, "wb");
342 ERR(!b, "%s", sig_file_name);
344 ERR(i2d_CMS_bio_stream(b, cms, NULL, 0) < 0,
345 "%s", sig_file_name);
347 ERR(i2d_PKCS7_bio(b, pkcs7) < 0,
348 "%s", sig_file_name);
359 /* Open the destination file now so that we can shovel the module data
360 * across as we read it.
362 bd = BIO_new_file(dest_name, "wb");
363 ERR(!bd, "%s", dest_name);
365 /* Append the marker and the PKCS#7 message to the destination file */
366 ERR(BIO_reset(bm) < 0, "%s", module_name);
367 while ((n = BIO_read(bm, buf, sizeof(buf))),
369 ERR(BIO_write(bd, buf, n) < 0, "%s", dest_name);
372 ERR(n < 0, "%s", module_name);
373 module_size = BIO_number_written(bd);
377 ERR(i2d_CMS_bio_stream(bd, cms, NULL, 0) < 0, "%s", dest_name);
379 ERR(i2d_PKCS7_bio(bd, pkcs7) < 0, "%s", dest_name);
384 /* Read the raw signature file and write the data to the
387 b = BIO_new_file(raw_sig_name, "rb");
388 ERR(!b, "%s", raw_sig_name);
389 while ((n = BIO_read(b, buf, sizeof(buf))), n > 0)
390 ERR(BIO_write(bd, buf, n) < 0, "%s", dest_name);
394 sig_size = BIO_number_written(bd) - module_size;
395 sig_info.sig_len = htonl(sig_size);
396 ERR(BIO_write(bd, &sig_info, sizeof(sig_info)) < 0, "%s", dest_name);
397 ERR(BIO_write(bd, magic_number, sizeof(magic_number) - 1) < 0, "%s", dest_name);
399 ERR(BIO_free(bd) < 0, "%s", dest_name);
401 /* Finally, if we're signing in place, replace the original. */
403 ERR(rename(dest_name, module_name) < 0, "%s", dest_name);