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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
34
35
36
37
38
39
40
41
42
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
53struct module_signature {
54 uint8_t algo;
55 uint8_t hash;
56 uint8_t id_type;
57 uint8_t signer_len;
58 uint8_t key_id_len;
59 uint8_t __pad[3];
60 uint32_t sig_len;
61};
62
63#define PKEY_ID_PKCS7 2
64
65static char magic_number[] = "~Module signature appended~\n";
66
67static __attribute__((noreturn))
68void 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
77static 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
93static 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
112static const char *key_pass;
113
114static 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
128 key_pass = NULL;
129
130 return pwlen;
131}
132
133static 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
168static 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
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
196 x509 = d2i_X509_bio(b, NULL);
197 else
198
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
207int 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
288 bm = BIO_new_file(module_name, "rb");
289 ERR(!bm, "%s", module_name);
290
291 if (!raw_sig) {
292
293
294
295 private_key = read_private_key(private_key_name);
296 x509 = read_x509(x509_name);
297
298
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
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
351
352
353 bd = BIO_new_file(dest_name, "wb");
354 ERR(!bd, "%s", dest_name);
355
356
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
376
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
393 if (replace_orig)
394 ERR(rename(dest_name, module_name) < 0, "%s", dest_name);
395
396 return 0;
397}
398
