blob: 53af6dc3e6c1779fbde3c5a641a880f52aa768e5
1 | /* Sign a module file using the given key. |
2 | * |
3 | * Copyright © 2014-2016 Red Hat, Inc. All Rights Reserved. |
4 | * Copyright © 2015 Intel Corporation. |
5 | * Copyright © 2016 Hewlett Packard Enterprise Development LP |
6 | * |
7 | * Authors: David Howells <dhowells@redhat.com> |
8 | * David Woodhouse <dwmw2@infradead.org> |
9 | * Juerg Haefliger <juerg.haefliger@hpe.com> |
10 | * |
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. |
15 | */ |
16 | #define _GNU_SOURCE |
17 | #include <stdio.h> |
18 | #include <stdlib.h> |
19 | #include <stdint.h> |
20 | #include <stdbool.h> |
21 | #include <string.h> |
22 | #include <getopt.h> |
23 | #include <err.h> |
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> |
31 | |
32 | /* |
33 | * Use CMS if we have openssl-1.0.0 or newer available - otherwise we have to |
34 | * assume that it's not available and its header file is missing and that we |
35 | * should use PKCS#7 instead. Switching to the older PKCS#7 format restricts |
36 | * the options we have on specifying the X.509 certificate we want. |
37 | * |
38 | * Further, older versions of OpenSSL don't support manually adding signers to |
39 | * the PKCS#7 message so have to accept that we get a certificate included in |
40 | * the signature message. Nor do such older versions of OpenSSL support |
41 | * signing with anything other than SHA1 - so we're stuck with that if such is |
42 | * the case. |
43 | */ |
44 | #if OPENSSL_VERSION_NUMBER < 0x10000000L || defined(OPENSSL_NO_CMS) |
45 | #define USE_PKCS7 |
46 | #endif |
47 | #ifndef USE_PKCS7 |
48 | #include <openssl/cms.h> |
49 | #else |
50 | #include <openssl/pkcs7.h> |
51 | #endif |
52 | |
53 | struct module_signature { |
54 | uint8_t algo; /* Public-key crypto algorithm [0] */ |
55 | uint8_t hash; /* Digest algorithm [0] */ |
56 | uint8_t id_type; /* Key identifier type [PKEY_ID_PKCS7] */ |
57 | uint8_t signer_len; /* Length of signer's name [0] */ |
58 | uint8_t key_id_len; /* Length of key identifier [0] */ |
59 | uint8_t __pad[3]; |
60 | uint32_t sig_len; /* Length of signature data */ |
61 | }; |
62 | |
63 | #define PKEY_ID_PKCS7 2 |
64 | |
65 | static char magic_number[] = "~Module signature appended~\n"; |
66 | |
67 | static __attribute__((noreturn)) |
68 | void format(void) |
69 | { |
70 | fprintf(stderr, |
71 | "Usage: scripts/sign-file [-dp] <hash algo> <key> <x509> <module> [<dest>]\n"); |
72 | fprintf(stderr, |
73 | " scripts/sign-file -s <raw sig> <hash algo> <x509> <module> [<dest>]\n"); |
74 | exit(2); |
75 | } |
76 | |
77 | static void display_openssl_errors(int l) |
78 | { |
79 | const char *file; |
80 | char buf[120]; |
81 | int e, line; |
82 | |
83 | if (ERR_peek_error() == 0) |
84 | return; |
85 | fprintf(stderr, "At main.c:%d:\n", l); |
86 | |
87 | while ((e = ERR_get_error_line(&file, &line))) { |
88 | ERR_error_string(e, buf); |
89 | fprintf(stderr, "- SSL %s: %s:%d\n", buf, file, line); |
90 | } |
91 | } |
92 | |
93 | static void drain_openssl_errors(void) |
94 | { |
95 | const char *file; |
96 | int line; |
97 | |
98 | if (ERR_peek_error() == 0) |
99 | return; |
100 | while (ERR_get_error_line(&file, &line)) {} |
101 | } |
102 | |
103 | #define ERR(cond, fmt, ...) \ |
104 | do { \ |
105 | bool __cond = (cond); \ |
106 | display_openssl_errors(__LINE__); \ |
107 | if (__cond) { \ |
108 | err(1, fmt, ## __VA_ARGS__); \ |
109 | } \ |
110 | } while(0) |
111 | |
112 | static const char *key_pass; |
113 | |
114 | static int pem_pw_cb(char *buf, int len, int w, void *v) |
115 | { |
116 | int pwlen; |
117 | |
118 | if (!key_pass) |
119 | return -1; |
120 | |
121 | pwlen = strlen(key_pass); |
122 | if (pwlen >= len) |
123 | return -1; |
124 | |
125 | strcpy(buf, key_pass); |
126 | |
127 | /* If it's wrong, don't keep trying it. */ |
128 | key_pass = NULL; |
129 | |
130 | return pwlen; |
131 | } |
132 | |
133 | static EVP_PKEY *read_private_key(const char *private_key_name) |
134 | { |
135 | EVP_PKEY *private_key; |
136 | |
137 | if (!strncmp(private_key_name, "pkcs11:", 7)) { |
138 | ENGINE *e; |
139 | |
140 | ENGINE_load_builtin_engines(); |
141 | drain_openssl_errors(); |
142 | e = ENGINE_by_id("pkcs11"); |
143 | ERR(!e, "Load PKCS#11 ENGINE"); |
144 | if (ENGINE_init(e)) |
145 | drain_openssl_errors(); |
146 | else |
147 | ERR(1, "ENGINE_init"); |
148 | if (key_pass) |
149 | ERR(!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0), |
150 | "Set PKCS#11 PIN"); |
151 | private_key = ENGINE_load_private_key(e, private_key_name, |
152 | NULL, NULL); |
153 | ERR(!private_key, "%s", private_key_name); |
154 | } else { |
155 | BIO *b; |
156 | |
157 | b = BIO_new_file(private_key_name, "rb"); |
158 | ERR(!b, "%s", private_key_name); |
159 | private_key = PEM_read_bio_PrivateKey(b, NULL, pem_pw_cb, |
160 | NULL); |
161 | ERR(!private_key, "%s", private_key_name); |
162 | BIO_free(b); |
163 | } |
164 | |
165 | return private_key; |
166 | } |
167 | |
168 | static X509 *read_x509(const char *x509_name) |
169 | { |
170 | unsigned char buf[2]; |
171 | X509 *x509; |
172 | BIO *b; |
173 | int n; |
174 | |
175 | b = BIO_new_file(x509_name, "rb"); |
176 | ERR(!b, "%s", x509_name); |
177 | |
178 | /* Look at the first two bytes of the file to determine the encoding */ |
179 | n = BIO_read(b, buf, 2); |
180 | if (n != 2) { |
181 | if (BIO_should_retry(b)) { |
182 | fprintf(stderr, "%s: Read wanted retry\n", x509_name); |
183 | exit(1); |
184 | } |
185 | if (n >= 0) { |
186 | fprintf(stderr, "%s: Short read\n", x509_name); |
187 | exit(1); |
188 | } |
189 | ERR(1, "%s", x509_name); |
190 | } |
191 | |
192 | ERR(BIO_reset(b) != 0, "%s", x509_name); |
193 | |
194 | if (buf[0] == 0x30 && buf[1] >= 0x81 && buf[1] <= 0x84) |
195 | /* Assume raw DER encoded X.509 */ |
196 | x509 = d2i_X509_bio(b, NULL); |
197 | else |
198 | /* Assume PEM encoded X.509 */ |
199 | x509 = PEM_read_bio_X509(b, NULL, NULL, NULL); |
200 | |
201 | BIO_free(b); |
202 | ERR(!x509, "%s", x509_name); |
203 | |
204 | return x509; |
205 | } |
206 | |
207 | int main(int argc, char **argv) |
208 | { |
209 | struct module_signature sig_info = { .id_type = PKEY_ID_PKCS7 }; |
210 | char *hash_algo = NULL; |
211 | char *private_key_name = NULL, *raw_sig_name = NULL; |
212 | char *x509_name, *module_name, *dest_name; |
213 | bool save_sig = false, replace_orig; |
214 | bool sign_only = false; |
215 | bool raw_sig = false; |
216 | unsigned char buf[4096]; |
217 | unsigned long module_size, sig_size; |
218 | unsigned int use_signed_attrs; |
219 | const EVP_MD *digest_algo; |
220 | EVP_PKEY *private_key; |
221 | #ifndef USE_PKCS7 |
222 | CMS_ContentInfo *cms = NULL; |
223 | unsigned int use_keyid = 0; |
224 | #else |
225 | PKCS7 *pkcs7 = NULL; |
226 | #endif |
227 | X509 *x509; |
228 | BIO *bd, *bm; |
229 | int opt, n; |
230 | OpenSSL_add_all_algorithms(); |
231 | ERR_load_crypto_strings(); |
232 | ERR_clear_error(); |
233 | |
234 | key_pass = getenv("KBUILD_SIGN_PIN"); |
235 | |
236 | #ifndef USE_PKCS7 |
237 | use_signed_attrs = CMS_NOATTR; |
238 | #else |
239 | use_signed_attrs = PKCS7_NOATTR; |
240 | #endif |
241 | |
242 | do { |
243 | opt = getopt(argc, argv, "sdpk"); |
244 | switch (opt) { |
245 | case 's': raw_sig = true; break; |
246 | case 'p': save_sig = true; break; |
247 | case 'd': sign_only = true; save_sig = true; break; |
248 | #ifndef USE_PKCS7 |
249 | case 'k': use_keyid = CMS_USE_KEYID; break; |
250 | #endif |
251 | case -1: break; |
252 | default: format(); |
253 | } |
254 | } while (opt != -1); |
255 | |
256 | argc -= optind; |
257 | argv += optind; |
258 | if (argc < 4 || argc > 5) |
259 | format(); |
260 | |
261 | if (raw_sig) { |
262 | raw_sig_name = argv[0]; |
263 | hash_algo = argv[1]; |
264 | } else { |
265 | hash_algo = argv[0]; |
266 | private_key_name = argv[1]; |
267 | } |
268 | x509_name = argv[2]; |
269 | module_name = argv[3]; |
270 | if (argc == 5) { |
271 | dest_name = argv[4]; |
272 | replace_orig = false; |
273 | } else { |
274 | ERR(asprintf(&dest_name, "%s.~signed~", module_name) < 0, |
275 | "asprintf"); |
276 | replace_orig = true; |
277 | } |
278 | |
279 | #ifdef USE_PKCS7 |
280 | if (strcmp(hash_algo, "sha1") != 0) { |
281 | fprintf(stderr, "sign-file: %s only supports SHA1 signing\n", |
282 | OPENSSL_VERSION_TEXT); |
283 | exit(3); |
284 | } |
285 | #endif |
286 | |
287 | /* Open the module file */ |
288 | bm = BIO_new_file(module_name, "rb"); |
289 | ERR(!bm, "%s", module_name); |
290 | |
291 | if (!raw_sig) { |
292 | /* Read the private key and the X.509 cert the PKCS#7 message |
293 | * will point to. |
294 | */ |
295 | private_key = read_private_key(private_key_name); |
296 | x509 = read_x509(x509_name); |
297 | |
298 | /* Digest the module data. */ |
299 | OpenSSL_add_all_digests(); |
300 | display_openssl_errors(__LINE__); |
301 | digest_algo = EVP_get_digestbyname(hash_algo); |
302 | ERR(!digest_algo, "EVP_get_digestbyname"); |
303 | |
304 | #ifndef USE_PKCS7 |
305 | /* Load the signature message from the digest buffer. */ |
306 | cms = CMS_sign(NULL, NULL, NULL, NULL, |
307 | CMS_NOCERTS | CMS_PARTIAL | CMS_BINARY | |
308 | CMS_DETACHED | CMS_STREAM); |
309 | ERR(!cms, "CMS_sign"); |
310 | |
311 | ERR(!CMS_add1_signer(cms, x509, private_key, digest_algo, |
312 | CMS_NOCERTS | CMS_BINARY | |
313 | CMS_NOSMIMECAP | use_keyid | |
314 | use_signed_attrs), |
315 | "CMS_add1_signer"); |
316 | ERR(CMS_final(cms, bm, NULL, CMS_NOCERTS | CMS_BINARY) < 0, |
317 | "CMS_final"); |
318 | |
319 | #else |
320 | pkcs7 = PKCS7_sign(x509, private_key, NULL, bm, |
321 | PKCS7_NOCERTS | PKCS7_BINARY | |
322 | PKCS7_DETACHED | use_signed_attrs); |
323 | ERR(!pkcs7, "PKCS7_sign"); |
324 | #endif |
325 | |
326 | if (save_sig) { |
327 | char *sig_file_name; |
328 | BIO *b; |
329 | |
330 | ERR(asprintf(&sig_file_name, "%s.p7s", module_name) < 0, |
331 | "asprintf"); |
332 | b = BIO_new_file(sig_file_name, "wb"); |
333 | ERR(!b, "%s", sig_file_name); |
334 | #ifndef USE_PKCS7 |
335 | ERR(i2d_CMS_bio_stream(b, cms, NULL, 0) < 0, |
336 | "%s", sig_file_name); |
337 | #else |
338 | ERR(i2d_PKCS7_bio(b, pkcs7) < 0, |
339 | "%s", sig_file_name); |
340 | #endif |
341 | BIO_free(b); |
342 | } |
343 | |
344 | if (sign_only) { |
345 | BIO_free(bm); |
346 | return 0; |
347 | } |
348 | } |
349 | |
350 | /* Open the destination file now so that we can shovel the module data |
351 | * across as we read it. |
352 | */ |
353 | bd = BIO_new_file(dest_name, "wb"); |
354 | ERR(!bd, "%s", dest_name); |
355 | |
356 | /* Append the marker and the PKCS#7 message to the destination file */ |
357 | ERR(BIO_reset(bm) < 0, "%s", module_name); |
358 | while ((n = BIO_read(bm, buf, sizeof(buf))), |
359 | n > 0) { |
360 | ERR(BIO_write(bd, buf, n) < 0, "%s", dest_name); |
361 | } |
362 | BIO_free(bm); |
363 | ERR(n < 0, "%s", module_name); |
364 | module_size = BIO_number_written(bd); |
365 | |
366 | if (!raw_sig) { |
367 | #ifndef USE_PKCS7 |
368 | ERR(i2d_CMS_bio_stream(bd, cms, NULL, 0) < 0, "%s", dest_name); |
369 | #else |
370 | ERR(i2d_PKCS7_bio(bd, pkcs7) < 0, "%s", dest_name); |
371 | #endif |
372 | } else { |
373 | BIO *b; |
374 | |
375 | /* Read the raw signature file and write the data to the |
376 | * destination file |
377 | */ |
378 | b = BIO_new_file(raw_sig_name, "rb"); |
379 | ERR(!b, "%s", raw_sig_name); |
380 | while ((n = BIO_read(b, buf, sizeof(buf))), n > 0) |
381 | ERR(BIO_write(bd, buf, n) < 0, "%s", dest_name); |
382 | BIO_free(b); |
383 | } |
384 | |
385 | sig_size = BIO_number_written(bd) - module_size; |
386 | sig_info.sig_len = htonl(sig_size); |
387 | ERR(BIO_write(bd, &sig_info, sizeof(sig_info)) < 0, "%s", dest_name); |
388 | ERR(BIO_write(bd, magic_number, sizeof(magic_number) - 1) < 0, "%s", dest_name); |
389 | |
390 | ERR(BIO_free(bd) < 0, "%s", dest_name); |
391 | |
392 | /* Finally, if we're signing in place, replace the original. */ |
393 | if (replace_orig) |
394 | ERR(rename(dest_name, module_name) < 0, "%s", dest_name); |
395 | |
396 | return 0; |
397 | } |
398 |