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 #if OPENSSL_VERSION_MAJOR >= 3 31 # define USE_PKCS11_PROVIDER 32 # include <openssl/provider.h> 33 # include <openssl/store.h> 34 #else 35 # if !defined(OPENSSL_NO_ENGINE) && !defined(OPENSSL_NO_DEPRECATED_3_0) 36 # define USE_PKCS11_ENGINE 37 # include <openssl/engine.h> 38 # endif 39 #endif 40 #include "ssl-common.h" 41 42 /* 43 * Use CMS if we have openssl-1.0.0 or newer available - otherwise we have to 44 * assume that it's not available and its header file is missing and that we 45 * should use PKCS#7 instead. Switching to the older PKCS#7 format restricts 46 * the options we have on specifying the X.509 certificate we want. 47 * 48 * Further, older versions of OpenSSL don't support manually adding signers to 49 * the PKCS#7 message so have to accept that we get a certificate included in 50 * the signature message. Nor do such older versions of OpenSSL support 51 * signing with anything other than SHA1 - so we're stuck with that if such is 52 * the case. 53 */ 54 #if defined(LIBRESSL_VERSION_NUMBER) || \ 55 OPENSSL_VERSION_NUMBER < 0x10000000L || \ 56 defined(OPENSSL_NO_CMS) 57 #define USE_PKCS7 58 #endif 59 #ifndef USE_PKCS7 60 #include <openssl/cms.h> 61 #else 62 #include <openssl/pkcs7.h> 63 #endif 64 65 struct module_signature { 66 uint8_t algo; /* Public-key crypto algorithm [0] */ 67 uint8_t hash; /* Digest algorithm [0] */ 68 uint8_t id_type; /* Key identifier type [PKEY_ID_PKCS7] */ 69 uint8_t signer_len; /* Length of signer's name [0] */ 70 uint8_t key_id_len; /* Length of key identifier [0] */ 71 uint8_t __pad[3]; 72 uint32_t sig_len; /* Length of signature data */ 73 }; 74 75 #define PKEY_ID_PKCS7 2 76 77 static char magic_number[] = "~Module signature appended~\n"; 78 79 static __attribute__((noreturn)) 80 void format(void) 81 { 82 fprintf(stderr, 83 "Usage: scripts/sign-file [-dp] <hash algo> <key> <x509> <module> [<dest>]\n"); 84 fprintf(stderr, 85 " scripts/sign-file -s <raw sig> <hash algo> <x509> <module> [<dest>]\n"); 86 exit(2); 87 } 88 89 static const char *key_pass; 90 91 static int pem_pw_cb(char *buf, int len, int w, void *v) 92 { 93 int pwlen; 94 95 if (!key_pass) 96 return -1; 97 98 pwlen = strlen(key_pass); 99 if (pwlen >= len) 100 return -1; 101 102 strcpy(buf, key_pass); 103 104 /* If it's wrong, don't keep trying it. */ 105 key_pass = NULL; 106 107 return pwlen; 108 } 109 110 static EVP_PKEY *read_private_key_pkcs11(const char *private_key_name) 111 { 112 EVP_PKEY *private_key = NULL; 113 #ifdef USE_PKCS11_PROVIDER 114 OSSL_STORE_CTX *store; 115 116 if (!OSSL_PROVIDER_try_load(NULL, "pkcs11", true)) 117 ERR(1, "OSSL_PROVIDER_try_load(pkcs11)"); 118 if (!OSSL_PROVIDER_try_load(NULL, "default", true)) 119 ERR(1, "OSSL_PROVIDER_try_load(default)"); 120 121 store = OSSL_STORE_open(private_key_name, NULL, NULL, NULL, NULL); 122 ERR(!store, "OSSL_STORE_open"); 123 124 while (!OSSL_STORE_eof(store)) { 125 OSSL_STORE_INFO *info = OSSL_STORE_load(store); 126 127 if (!info) { 128 drain_openssl_errors(__LINE__, 0); 129 continue; 130 } 131 if (OSSL_STORE_INFO_get_type(info) == OSSL_STORE_INFO_PKEY) { 132 private_key = OSSL_STORE_INFO_get1_PKEY(info); 133 ERR(!private_key, "OSSL_STORE_INFO_get1_PKEY"); 134 } 135 OSSL_STORE_INFO_free(info); 136 if (private_key) 137 break; 138 } 139 OSSL_STORE_close(store); 140 #elif defined(USE_PKCS11_ENGINE) 141 ENGINE *e; 142 143 ENGINE_load_builtin_engines(); 144 drain_openssl_errors(__LINE__, 1); 145 e = ENGINE_by_id("pkcs11"); 146 ERR(!e, "Load PKCS#11 ENGINE"); 147 if (ENGINE_init(e)) 148 drain_openssl_errors(__LINE__, 1); 149 else 150 ERR(1, "ENGINE_init"); 151 if (key_pass) 152 ERR(!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0), "Set PKCS#11 PIN"); 153 private_key = ENGINE_load_private_key(e, private_key_name, NULL, NULL); 154 ERR(!private_key, "%s", private_key_name); 155 #else 156 fprintf(stderr, "no pkcs11 engine/provider available\n"); 157 exit(1); 158 #endif 159 return private_key; 160 } 161 162 static EVP_PKEY *read_private_key(const char *private_key_name) 163 { 164 if (!strncmp(private_key_name, "pkcs11:", 7)) { 165 return read_private_key_pkcs11(private_key_name); 166 } else { 167 EVP_PKEY *private_key; 168 BIO *b; 169 170 b = BIO_new_file(private_key_name, "rb"); 171 ERR(!b, "%s", private_key_name); 172 private_key = PEM_read_bio_PrivateKey(b, NULL, pem_pw_cb, 173 NULL); 174 ERR(!private_key, "%s", private_key_name); 175 BIO_free(b); 176 177 return private_key; 178 } 179 } 180 181 static X509 *read_x509(const char *x509_name) 182 { 183 unsigned char buf[2]; 184 X509 *x509; 185 BIO *b; 186 int n; 187 188 b = BIO_new_file(x509_name, "rb"); 189 ERR(!b, "%s", x509_name); 190 191 /* Look at the first two bytes of the file to determine the encoding */ 192 n = BIO_read(b, buf, 2); 193 if (n != 2) { 194 if (BIO_should_retry(b)) { 195 fprintf(stderr, "%s: Read wanted retry\n", x509_name); 196 exit(1); 197 } 198 if (n >= 0) { 199 fprintf(stderr, "%s: Short read\n", x509_name); 200 exit(1); 201 } 202 ERR(1, "%s", x509_name); 203 } 204 205 ERR(BIO_reset(b) != 0, "%s", x509_name); 206 207 if (buf[0] == 0x30 && buf[1] >= 0x81 && buf[1] <= 0x84) 208 /* Assume raw DER encoded X.509 */ 209 x509 = d2i_X509_bio(b, NULL); 210 else 211 /* Assume PEM encoded X.509 */ 212 x509 = PEM_read_bio_X509(b, NULL, NULL, NULL); 213 214 BIO_free(b); 215 ERR(!x509, "%s", x509_name); 216 217 return x509; 218 } 219 220 int main(int argc, char **argv) 221 { 222 struct module_signature sig_info = { .id_type = PKEY_ID_PKCS7 }; 223 char *hash_algo = NULL; 224 char *private_key_name = NULL, *raw_sig_name = NULL; 225 char *x509_name, *module_name, *dest_name; 226 bool save_sig = false, replace_orig; 227 bool sign_only = false; 228 bool raw_sig = false; 229 unsigned char buf[4096]; 230 unsigned long module_size, sig_size; 231 unsigned int use_signed_attrs; 232 const EVP_MD *digest_algo; 233 EVP_PKEY *private_key; 234 #ifndef USE_PKCS7 235 CMS_ContentInfo *cms = NULL; 236 unsigned int use_keyid = 0; 237 #else 238 PKCS7 *pkcs7 = NULL; 239 #endif 240 X509 *x509; 241 BIO *bd, *bm; 242 int opt, n; 243 OpenSSL_add_all_algorithms(); 244 ERR_load_crypto_strings(); 245 ERR_clear_error(); 246 247 key_pass = getenv("KBUILD_SIGN_PIN"); 248 249 #ifndef USE_PKCS7 250 use_signed_attrs = CMS_NOATTR; 251 #else 252 use_signed_attrs = PKCS7_NOATTR; 253 #endif 254 255 do { 256 opt = getopt(argc, argv, "sdpk"); 257 switch (opt) { 258 case 's': raw_sig = true; break; 259 case 'p': save_sig = true; break; 260 case 'd': sign_only = true; save_sig = true; break; 261 #ifndef USE_PKCS7 262 case 'k': use_keyid = CMS_USE_KEYID; break; 263 #endif 264 case -1: break; 265 default: format(); 266 } 267 } while (opt != -1); 268 269 argc -= optind; 270 argv += optind; 271 if (argc < 4 || argc > 5) 272 format(); 273 274 if (raw_sig) { 275 raw_sig_name = argv[0]; 276 hash_algo = argv[1]; 277 } else { 278 hash_algo = argv[0]; 279 private_key_name = argv[1]; 280 } 281 x509_name = argv[2]; 282 module_name = argv[3]; 283 if (argc == 5 && strcmp(argv[3], argv[4]) != 0) { 284 dest_name = argv[4]; 285 replace_orig = false; 286 } else { 287 ERR(asprintf(&dest_name, "%s.~signed~", module_name) < 0, 288 "asprintf"); 289 replace_orig = true; 290 } 291 292 #ifdef USE_PKCS7 293 if (strcmp(hash_algo, "sha1") != 0) { 294 fprintf(stderr, "sign-file: %s only supports SHA1 signing\n", 295 OPENSSL_VERSION_TEXT); 296 exit(3); 297 } 298 #endif 299 300 /* Open the module file */ 301 bm = BIO_new_file(module_name, "rb"); 302 ERR(!bm, "%s", module_name); 303 304 if (!raw_sig) { 305 /* Read the private key and the X.509 cert the PKCS#7 message 306 * will point to. 307 */ 308 private_key = read_private_key(private_key_name); 309 x509 = read_x509(x509_name); 310 311 /* Digest the module data. */ 312 OpenSSL_add_all_digests(); 313 drain_openssl_errors(__LINE__, 0); 314 digest_algo = EVP_get_digestbyname(hash_algo); 315 ERR(!digest_algo, "EVP_get_digestbyname"); 316 317 #ifndef USE_PKCS7 318 /* Load the signature message from the digest buffer. */ 319 cms = CMS_sign(NULL, NULL, NULL, NULL, 320 CMS_NOCERTS | CMS_PARTIAL | CMS_BINARY | 321 CMS_DETACHED | CMS_STREAM); 322 ERR(!cms, "CMS_sign"); 323 324 ERR(!CMS_add1_signer(cms, x509, private_key, digest_algo, 325 CMS_NOCERTS | CMS_BINARY | 326 CMS_NOSMIMECAP | use_keyid | 327 use_signed_attrs), 328 "CMS_add1_signer"); 329 ERR(CMS_final(cms, bm, NULL, CMS_NOCERTS | CMS_BINARY) != 1, 330 "CMS_final"); 331 332 #else 333 pkcs7 = PKCS7_sign(x509, private_key, NULL, bm, 334 PKCS7_NOCERTS | PKCS7_BINARY | 335 PKCS7_DETACHED | use_signed_attrs); 336 ERR(!pkcs7, "PKCS7_sign"); 337 #endif 338 339 if (save_sig) { 340 char *sig_file_name; 341 BIO *b; 342 343 ERR(asprintf(&sig_file_name, "%s.p7s", module_name) < 0, 344 "asprintf"); 345 b = BIO_new_file(sig_file_name, "wb"); 346 ERR(!b, "%s", sig_file_name); 347 #ifndef USE_PKCS7 348 ERR(i2d_CMS_bio_stream(b, cms, NULL, 0) != 1, 349 "%s", sig_file_name); 350 #else 351 ERR(i2d_PKCS7_bio(b, pkcs7) != 1, 352 "%s", sig_file_name); 353 #endif 354 BIO_free(b); 355 } 356 357 if (sign_only) { 358 BIO_free(bm); 359 return 0; 360 } 361 } 362 363 /* Open the destination file now so that we can shovel the module data 364 * across as we read it. 365 */ 366 bd = BIO_new_file(dest_name, "wb"); 367 ERR(!bd, "%s", dest_name); 368 369 /* Append the marker and the PKCS#7 message to the destination file */ 370 ERR(BIO_reset(bm) < 0, "%s", module_name); 371 while ((n = BIO_read(bm, buf, sizeof(buf))), 372 n > 0) { 373 ERR(BIO_write(bd, buf, n) < 0, "%s", dest_name); 374 } 375 BIO_free(bm); 376 ERR(n < 0, "%s", module_name); 377 module_size = BIO_number_written(bd); 378 379 if (!raw_sig) { 380 #ifndef USE_PKCS7 381 ERR(i2d_CMS_bio_stream(bd, cms, NULL, 0) != 1, "%s", dest_name); 382 #else 383 ERR(i2d_PKCS7_bio(bd, pkcs7) != 1, "%s", dest_name); 384 #endif 385 } else { 386 BIO *b; 387 388 /* Read the raw signature file and write the data to the 389 * destination file 390 */ 391 b = BIO_new_file(raw_sig_name, "rb"); 392 ERR(!b, "%s", raw_sig_name); 393 while ((n = BIO_read(b, buf, sizeof(buf))), n > 0) 394 ERR(BIO_write(bd, buf, n) < 0, "%s", dest_name); 395 BIO_free(b); 396 } 397 398 sig_size = BIO_number_written(bd) - module_size; 399 sig_info.sig_len = htonl(sig_size); 400 ERR(BIO_write(bd, &sig_info, sizeof(sig_info)) < 0, "%s", dest_name); 401 ERR(BIO_write(bd, magic_number, sizeof(magic_number) - 1) < 0, "%s", dest_name); 402 403 ERR(BIO_free(bd) != 1, "%s", dest_name); 404 405 /* Finally, if we're signing in place, replace the original. */ 406 if (replace_orig) 407 ERR(rename(dest_name, module_name) < 0, "%s", dest_name); 408 409 return 0; 410 } 411