tests/crypto-tls-x509-helpers.c

   1 /*
   2  * Copyright (C) 2015 Red Hat, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library.  If not, see
  16  * <http://www.gnu.org/licenses/>.
  17  *
  18  * Author: Daniel P. Berrange <berrange@redhat.com>
  19  */
  20
  21 #include "qemu/osdep.h"
  22
  23 #include "crypto-tls-x509-helpers.h"
  24 #include "qemu/sockets.h"
  25
  26 #ifdef QCRYPTO_HAVE_TLS_TEST_SUPPORT
  27
  28 /*
  29  * This stores some static data that is needed when
  30  * encoding extensions in the x509 certs
  31  */
  32 ASN1_TYPE pkix_asn1;
  33
  34 /*
  35  * To avoid consuming random entropy to generate keys,
  36  * here's one we prepared earlier :-)
  37  */
  38 gnutls_x509_privkey_t privkey;
  39 # define PRIVATE_KEY                                              \
  40     "-----BEGIN PRIVATE KEY-----\n"                               \
  41     "MIICdQIBADANBgkqhkiG9w0BAQEFAASCAl8wggJbAgEAAoGBALVcr\n"     \
  42     "BL40Tm6yq88FBhJNw1aaoCjmtg0l4dWQZ/e9Fimx4ARxFpT+ji4FE\n"     \
  43     "Cgl9s/SGqC+1nvlkm9ViSo0j7MKDbnDB+VRHDvMAzQhA2X7e8M0n9\n"     \
  44     "rPolUY2lIVC83q0BBaOBkCj2RSmT2xTEbbC2xLukSrg2WP/ihVOxc\n"     \
  45     "kXRuyFtzAgMBAAECgYB7slBexDwXrtItAMIH6m/U+LUpNe0Xx48OL\n"     \
  46     "IOn4a4whNgO/o84uIwygUK27ZGFZT0kAGAk8CdF9hA6ArcbQ62s1H\n"     \
  47     "myxrUbF9/mrLsQw1NEqpuUk9Ay2Tx5U/wPx35S3W/X2AvR/ZpTnCn\n"     \
  48     "2q/7ym9fyiSoj86drD7BTvmKXlOnOwQJBAPOFMp4mMa9NGpGuEssO\n"     \
  49     "m3Uwbp6lhcP0cA9MK+iOmeANpoKWfBdk5O34VbmeXnGYWEkrnX+9J\n"     \
  50     "bM4wVhnnBWtgBMCQQC+qAEmvwcfhauERKYznMVUVksyeuhxhCe7EK\n"     \
  51     "mPh+U2+g0WwdKvGDgO0PPt1gq0ILEjspMDeMHVdTwkaVBo/uMhAkA\n"     \
  52     "Z5SsZyCP2aTOPFDypXRdI4eqRcjaEPOUBq27r3uYb/jeboVb2weLa\n"     \
  53     "L1MmVuHiIHoa5clswPdWVI2y0em2IGoDAkBPSp/v9VKJEZabk9Frd\n"     \
  54     "a+7u4fanrM9QrEjY3KhduslSilXZZSxrWjjAJPyPiqFb3M8XXA26W\n"     \
  55     "nz1KYGnqYKhLcBAkB7dt57n9xfrhDpuyVEv+Uv1D3VVAhZlsaZ5Pp\n"     \
  56     "dcrhrkJn2sa/+O8OKvdrPSeeu/N5WwYhJf61+CPoenMp7IFci\n"         \
  57     "-----END PRIVATE KEY-----\n"
  58
  59 /*
  60  * This loads the private key we defined earlier
  61  */
  62 static gnutls_x509_privkey_t test_tls_load_key(void)
  63 {
  64     gnutls_x509_privkey_t key;
  65     const gnutls_datum_t data = { (unsigned char *)PRIVATE_KEY,
  66                                   strlen(PRIVATE_KEY) };
  67     int err;
  68
  69     err = gnutls_x509_privkey_init(&key);
  70     if (err < 0) {
  71         g_critical("Failed to init key %s", gnutls_strerror(err));
  72         abort();
  73     }
  74
  75     err = gnutls_x509_privkey_import(key, &data,
  76                                      GNUTLS_X509_FMT_PEM);
  77     if (err < 0) {
  78         if (err != GNUTLS_E_BASE64_UNEXPECTED_HEADER_ERROR &&
  79             err != GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) {
  80             g_critical("Failed to import key %s", gnutls_strerror(err));
  81             abort();
  82         }
  83
  84         err = gnutls_x509_privkey_import_pkcs8(
  85             key, &data, GNUTLS_X509_FMT_PEM, NULL, 0);
  86         if (err < 0) {
  87             g_critical("Failed to import PKCS8 key %s", gnutls_strerror(err));
  88             abort();
  89         }
  90     }
  91
  92     return key;
  93 }
  94
  95
  96 void test_tls_init(const char *keyfile)
  97 {
  98     gnutls_global_init();
  99
 100     if (asn1_array2tree(pkix_asn1_tab, &pkix_asn1, NULL) != ASN1_SUCCESS) {
 101         abort();
 102     }
 103
 104     privkey = test_tls_load_key();
 105     if (!g_file_set_contents(keyfile, PRIVATE_KEY, -1, NULL)) {
 106         abort();
 107     }
 108 }
 109
 110
 111 void test_tls_cleanup(const char *keyfile)
 112 {
 113     asn1_delete_structure(&pkix_asn1);
 114     unlink(keyfile);
 115 }
 116
 117 /*
 118  * Turns an ASN1 object into a DER encoded byte array
 119  */
 120 static void test_tls_der_encode(ASN1_TYPE src,
 121                                 const char *src_name,
 122                                 gnutls_datum_t *res)
 123 {
 124   int size;
 125   char *data = NULL;
 126
 127   size = 0;
 128   asn1_der_coding(src, src_name, NULL, &size, NULL);
 129
 130   data = g_new0(char, size);
 131
 132   asn1_der_coding(src, src_name, data, &size, NULL);
 133
 134   res->data = (unsigned char *)data;
 135   res->size = size;
 136 }
 137
 138
 139 static void
 140 test_tls_get_ipaddr(const char *addrstr,
 141                     char **data,
 142                     int *datalen)
 143 {
 144     struct addrinfo *res;
 145     struct addrinfo hints;
 146
 147     memset(&hints, 0, sizeof(hints));
 148     hints.ai_flags = AI_NUMERICHOST;
 149     g_assert(getaddrinfo(addrstr, NULL, &hints, &res) == 0);
 150
 151     *datalen = res->ai_addrlen;
 152     *data = g_new(char, *datalen);
 153     memcpy(*data, res->ai_addr, *datalen);
 154     freeaddrinfo(res);
 155 }
 156
 157 /*
 158  * This is a fairly lame x509 certificate generator.
 159  *
 160  * Do not copy/use this code for generating real certificates
 161  * since it leaves out many things that you would want in
 162  * certificates for real world usage.
 163  *
 164  * This is good enough only for doing tests of the QEMU
 165  * TLS certificate code
 166  */
 167 void
 168 test_tls_generate_cert(QCryptoTLSTestCertReq *req,
 169                        gnutls_x509_crt_t ca)
 170 {
 171     gnutls_x509_crt_t crt;
 172     int err;
 173     static char buffer[1024 * 1024];
 174     size_t size = sizeof(buffer);
 175     char serial[5] = { 1, 2, 3, 4, 0 };
 176     gnutls_datum_t der;
 177     time_t start = time(NULL) + (60 * 60 * req->start_offset);
 178     time_t expire = time(NULL) + (60 * 60 * (req->expire_offset
 179                                              ? req->expire_offset : 24));
 180
 181     /*
 182      * Prepare our new certificate object
 183      */
 184     err = gnutls_x509_crt_init(&crt);
 185     if (err < 0) {
 186         g_critical("Failed to initialize certificate %s", gnutls_strerror(err));
 187         abort();
 188     }
 189     err = gnutls_x509_crt_set_key(crt, privkey);
 190     if (err < 0) {
 191         g_critical("Failed to set certificate key %s", gnutls_strerror(err));
 192         abort();
 193     }
 194
 195     /*
 196      * A v3 certificate is required in order to be able
 197      * set any of the basic constraints, key purpose and
 198      * key usage data
 199      */
 200     gnutls_x509_crt_set_version(crt, 3);
 201
 202     if (req->country) {
 203         err = gnutls_x509_crt_set_dn_by_oid(
 204             crt, GNUTLS_OID_X520_COUNTRY_NAME, 0,
 205             req->country, strlen(req->country));
 206         if (err < 0) {
 207             g_critical("Failed to set certificate country name %s",
 208                        gnutls_strerror(err));
 209             abort();
 210         }
 211     }
 212     if (req->cn) {
 213         err = gnutls_x509_crt_set_dn_by_oid(
 214             crt, GNUTLS_OID_X520_COMMON_NAME, 0,
 215             req->cn, strlen(req->cn));
 216         if (err < 0) {
 217             g_critical("Failed to set certificate common name %s",
 218                        gnutls_strerror(err));
 219             abort();
 220         }
 221     }
 222
 223     /*
 224      * Setup the subject altnames, which are used
 225      * for hostname checks in live sessions
 226      */
 227     if (req->altname1) {
 228         err = gnutls_x509_crt_set_subject_alt_name(
 229             crt, GNUTLS_SAN_DNSNAME,
 230             req->altname1,
 231             strlen(req->altname1),
 232             GNUTLS_FSAN_APPEND);
 233         if (err < 0) {
 234             g_critical("Failed to set certificate alt name %s",
 235                        gnutls_strerror(err));
 236             abort();
 237         }
 238     }
 239     if (req->altname2) {
 240         err = gnutls_x509_crt_set_subject_alt_name(
 241             crt, GNUTLS_SAN_DNSNAME,
 242             req->altname2,
 243             strlen(req->altname2),
 244             GNUTLS_FSAN_APPEND);
 245         if (err < 0) {
 246             g_critical("Failed to set certificate %s alt name",
 247                        gnutls_strerror(err));
 248             abort();
 249         }
 250     }
 251
 252     /*
 253      * IP address need to be put into the cert in their
 254      * raw byte form, not strings, hence this is a little
 255      * more complicated
 256      */
 257     if (req->ipaddr1) {
 258         char *data;
 259         int len;
 260
 261         test_tls_get_ipaddr(req->ipaddr1, &data, &len);
 262
 263         err = gnutls_x509_crt_set_subject_alt_name(
 264             crt, GNUTLS_SAN_IPADDRESS,
 265             data, len, GNUTLS_FSAN_APPEND);
 266         if (err < 0) {
 267             g_critical("Failed to set certificate alt name %s",
 268                        gnutls_strerror(err));
 269             abort();
 270         }
 271         g_free(data);
 272     }
 273     if (req->ipaddr2) {
 274         char *data;
 275         int len;
 276
 277         test_tls_get_ipaddr(req->ipaddr2, &data, &len);
 278
 279         err = gnutls_x509_crt_set_subject_alt_name(
 280             crt, GNUTLS_SAN_IPADDRESS,
 281             data, len, GNUTLS_FSAN_APPEND);
 282         if (err < 0) {
 283             g_critical("Failed to set certificate alt name %s",
 284                        gnutls_strerror(err));
 285             abort();
 286         }
 287         g_free(data);
 288     }
 289
 290
 291     /*
 292      * Basic constraints are used to decide if the cert
 293      * is for a CA or not. We can't use the convenient
 294      * gnutls API for setting this, since it hardcodes
 295      * the 'critical' field which we want control over
 296      */
 297     if (req->basicConstraintsEnable) {
 298         ASN1_TYPE ext = ASN1_TYPE_EMPTY;
 299
 300         asn1_create_element(pkix_asn1, "PKIX1.BasicConstraints", &ext);
 301         asn1_write_value(ext, "cA",
 302                          req->basicConstraintsIsCA ? "TRUE" : "FALSE", 1);
 303         asn1_write_value(ext, "pathLenConstraint", NULL, 0);
 304         test_tls_der_encode(ext, "", &der);
 305         err = gnutls_x509_crt_set_extension_by_oid(
 306             crt, "2.5.29.19",
 307             der.data, der.size,
 308             req->basicConstraintsCritical);
 309         if (err < 0) {
 310             g_critical("Failed to set certificate basic constraints %s",
 311                        gnutls_strerror(err));
 312             g_free(der.data);
 313             abort();
 314         }
 315         asn1_delete_structure(&ext);
 316         g_free(der.data);
 317     }
 318
 319     /*
 320      * Next up the key usage extension. Again we can't
 321      * use the gnutls API since it hardcodes the extension
 322      * to be 'critical'
 323      */
 324     if (req->keyUsageEnable) {
 325         ASN1_TYPE ext = ASN1_TYPE_EMPTY;
 326         char str[2];
 327
 328         str[0] = req->keyUsageValue & 0xff;
 329         str[1] = (req->keyUsageValue >> 8) & 0xff;
 330
 331         asn1_create_element(pkix_asn1, "PKIX1.KeyUsage", &ext);
 332         asn1_write_value(ext, "", str, 9);
 333         test_tls_der_encode(ext, "", &der);
 334         err = gnutls_x509_crt_set_extension_by_oid(
 335             crt, "2.5.29.15",
 336             der.data, der.size,
 337             req->keyUsageCritical);
 338         if (err < 0) {
 339             g_critical("Failed to set certificate key usage %s",
 340                        gnutls_strerror(err));
 341             g_free(der.data);
 342             abort();
 343         }
 344         asn1_delete_structure(&ext);
 345         g_free(der.data);
 346     }
 347
 348     /*
 349      * Finally the key purpose extension. This time
 350      * gnutls has the opposite problem, always hardcoding
 351      * it to be non-critical. So once again we have to
 352      * set this the hard way building up ASN1 data ourselves
 353      */
 354     if (req->keyPurposeEnable) {
 355         ASN1_TYPE ext = ASN1_TYPE_EMPTY;
 356
 357         asn1_create_element(pkix_asn1, "PKIX1.ExtKeyUsageSyntax", &ext);
 358         if (req->keyPurposeOID1) {
 359             asn1_write_value(ext, "", "NEW", 1);
 360             asn1_write_value(ext, "?LAST", req->keyPurposeOID1, 1);
 361         }
 362         if (req->keyPurposeOID2) {
 363             asn1_write_value(ext, "", "NEW", 1);
 364             asn1_write_value(ext, "?LAST", req->keyPurposeOID2, 1);
 365         }
 366         test_tls_der_encode(ext, "", &der);
 367         err = gnutls_x509_crt_set_extension_by_oid(
 368             crt, "2.5.29.37",
 369             der.data, der.size,
 370             req->keyPurposeCritical);
 371         if (err < 0) {
 372             g_critical("Failed to set certificate key purpose %s",
 373                        gnutls_strerror(err));
 374             g_free(der.data);
 375             abort();
 376         }
 377         asn1_delete_structure(&ext);
 378         g_free(der.data);
 379     }
 380
 381     /*
 382      * Any old serial number will do, so lets pick 5
 383      */
 384     err = gnutls_x509_crt_set_serial(crt, serial, 5);
 385     if (err < 0) {
 386         g_critical("Failed to set certificate serial %s",
 387                    gnutls_strerror(err));
 388         abort();
 389     }
 390
 391     err = gnutls_x509_crt_set_activation_time(crt, start);
 392     if (err < 0) {
 393         g_critical("Failed to set certificate activation %s",
 394                    gnutls_strerror(err));
 395         abort();
 396     }
 397     err = gnutls_x509_crt_set_expiration_time(crt, expire);
 398     if (err < 0) {
 399         g_critical("Failed to set certificate expiration %s",
 400                    gnutls_strerror(err));
 401         abort();
 402     }
 403
 404
 405     /*
 406      * If no 'ca' is set then we are self signing
 407      * the cert. This is done for the root CA certs
 408      */
 409     err = gnutls_x509_crt_sign2(crt, ca ? ca : crt, privkey,
 410                                 GNUTLS_DIG_SHA256, 0);
 411     if (err < 0) {
 412         g_critical("Failed to sign certificate %s",
 413                    gnutls_strerror(err));
 414         abort();
 415     }
 416
 417     /*
 418      * Finally write the new cert out to disk
 419      */
 420     err = gnutls_x509_crt_export(
 421         crt, GNUTLS_X509_FMT_PEM, buffer, &size);
 422     if (err < 0) {
 423         g_critical("Failed to export certificate %s: %d",
 424                    gnutls_strerror(err), err);
 425         abort();
 426     }
 427
 428     if (!g_file_set_contents(req->filename, buffer, -1, NULL)) {
 429         g_critical("Failed to write certificate %s",
 430                    req->filename);
 431         abort();
 432     }
 433
 434     req->crt = crt;
 435 }
 436
 437
 438 void test_tls_write_cert_chain(const char *filename,
 439                                gnutls_x509_crt_t *certs,
 440                                size_t ncerts)
 441 {
 442     size_t i;
 443     size_t capacity = 1024, offset = 0;
 444     char *buffer = g_new0(char, capacity);
 445     int err;
 446
 447     for (i = 0; i < ncerts; i++) {
 448         size_t len = capacity - offset;
 449     retry:
 450         err = gnutls_x509_crt_export(certs[i], GNUTLS_X509_FMT_PEM,
 451                                      buffer + offset, &len);
 452         if (err < 0) {
 453             if (err == GNUTLS_E_SHORT_MEMORY_BUFFER) {
 454                 buffer = g_renew(char, buffer, offset + len);
 455                 capacity = offset + len;
 456                 goto retry;
 457             }
 458             g_critical("Failed to export certificate chain %s: %d",
 459                        gnutls_strerror(err), err);
 460             abort();
 461         }
 462         offset += len;
 463     }
 464
 465     if (!g_file_set_contents(filename, buffer, offset, NULL)) {
 466         abort();
 467     }
 468     g_free(buffer);
 469 }
 470
 471
 472 void test_tls_discard_cert(QCryptoTLSTestCertReq *req)
 473 {
 474     if (!req->crt) {
 475         return;
 476     }
 477
 478     gnutls_x509_crt_deinit(req->crt);
 479     req->crt = NULL;
 480
 481     if (getenv("QEMU_TEST_DEBUG_CERTS") == NULL) {
 482         unlink(req->filename);
 483     }
 484 }
 485
 486 #endif /* QCRYPTO_HAVE_TLS_TEST_SUPPORT */