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 <stdlib.h>
  22 #include <fcntl.h>
  23
  24 #include "config-host.h"
  25 #include "crypto-tls-x509-helpers.h"
  26 #include "qemu/sockets.h"
  27
  28 #ifdef QCRYPTO_HAVE_TLS_TEST_SUPPORT
  29
  30 /*
  31  * This stores some static data that is needed when
  32  * encoding extensions in the x509 certs
  33  */
  34 ASN1_TYPE pkix_asn1;
  35
  36 /*
  37  * To avoid consuming random entropy to generate keys,
  38  * here's one we prepared earlier :-)
  39  */
  40 gnutls_x509_privkey_t privkey;
  41 # define PRIVATE_KEY                                              \
  42     "-----BEGIN PRIVATE KEY-----\n"                               \
  43     "MIICdQIBADANBgkqhkiG9w0BAQEFAASCAl8wggJbAgEAAoGBALVcr\n"     \
  44     "BL40Tm6yq88FBhJNw1aaoCjmtg0l4dWQZ/e9Fimx4ARxFpT+ji4FE\n"     \
  45     "Cgl9s/SGqC+1nvlkm9ViSo0j7MKDbnDB+VRHDvMAzQhA2X7e8M0n9\n"     \
  46     "rPolUY2lIVC83q0BBaOBkCj2RSmT2xTEbbC2xLukSrg2WP/ihVOxc\n"     \
  47     "kXRuyFtzAgMBAAECgYB7slBexDwXrtItAMIH6m/U+LUpNe0Xx48OL\n"     \
  48     "IOn4a4whNgO/o84uIwygUK27ZGFZT0kAGAk8CdF9hA6ArcbQ62s1H\n"     \
  49     "myxrUbF9/mrLsQw1NEqpuUk9Ay2Tx5U/wPx35S3W/X2AvR/ZpTnCn\n"     \
  50     "2q/7ym9fyiSoj86drD7BTvmKXlOnOwQJBAPOFMp4mMa9NGpGuEssO\n"     \
  51     "m3Uwbp6lhcP0cA9MK+iOmeANpoKWfBdk5O34VbmeXnGYWEkrnX+9J\n"     \
  52     "bM4wVhnnBWtgBMCQQC+qAEmvwcfhauERKYznMVUVksyeuhxhCe7EK\n"     \
  53     "mPh+U2+g0WwdKvGDgO0PPt1gq0ILEjspMDeMHVdTwkaVBo/uMhAkA\n"     \
  54     "Z5SsZyCP2aTOPFDypXRdI4eqRcjaEPOUBq27r3uYb/jeboVb2weLa\n"     \
  55     "L1MmVuHiIHoa5clswPdWVI2y0em2IGoDAkBPSp/v9VKJEZabk9Frd\n"     \
  56     "a+7u4fanrM9QrEjY3KhduslSilXZZSxrWjjAJPyPiqFb3M8XXA26W\n"     \
  57     "nz1KYGnqYKhLcBAkB7dt57n9xfrhDpuyVEv+Uv1D3VVAhZlsaZ5Pp\n"     \
  58     "dcrhrkJn2sa/+O8OKvdrPSeeu/N5WwYhJf61+CPoenMp7IFci\n"         \
  59     "-----END PRIVATE KEY-----\n"
  60
  61 /*
  62  * This loads the private key we defined earlier
  63  */
  64 static gnutls_x509_privkey_t test_tls_load_key(void)
  65 {
  66     gnutls_x509_privkey_t key;
  67     const gnutls_datum_t data = { (unsigned char *)PRIVATE_KEY,
  68                                   strlen(PRIVATE_KEY) };
  69     int err;
  70
  71     err = gnutls_x509_privkey_init(&key);
  72     if (err < 0) {
  73         g_critical("Failed to init key %s", gnutls_strerror(err));
  74         abort();
  75     }
  76
  77     err = gnutls_x509_privkey_import(key, &data,
  78                                      GNUTLS_X509_FMT_PEM);
  79     if (err < 0) {
  80         if (err != GNUTLS_E_BASE64_UNEXPECTED_HEADER_ERROR &&
  81             err != GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) {
  82             g_critical("Failed to import key %s", gnutls_strerror(err));
  83             abort();
  84         }
  85
  86         err = gnutls_x509_privkey_import_pkcs8(
  87             key, &data, GNUTLS_X509_FMT_PEM, NULL, 0);
  88         if (err < 0) {
  89             g_critical("Failed to import PKCS8 key %s", gnutls_strerror(err));
  90             abort();
  91         }
  92     }
  93
  94     return key;
  95 }
  96
  97
  98 void test_tls_init(const char *keyfile)
  99 {
 100     gnutls_global_init();
 101
 102     if (asn1_array2tree(pkix_asn1_tab, &pkix_asn1, NULL) != ASN1_SUCCESS) {
 103         abort();
 104     }
 105
 106     privkey = test_tls_load_key();
 107     if (!g_file_set_contents(keyfile, PRIVATE_KEY, -1, NULL)) {
 108         abort();
 109     }
 110 }
 111
 112
 113 void test_tls_cleanup(const char *keyfile)
 114 {
 115     asn1_delete_structure(&pkix_asn1);
 116     unlink(keyfile);
 117 }
 118
 119 /*
 120  * Turns an ASN1 object into a DER encoded byte array
 121  */
 122 static void test_tls_der_encode(ASN1_TYPE src,
 123                                 const char *src_name,
 124                                 gnutls_datum_t *res)
 125 {
 126   int size;
 127   char *data = NULL;
 128
 129   size = 0;
 130   asn1_der_coding(src, src_name, NULL, &size, NULL);
 131
 132   data = g_new0(char, size);
 133
 134   asn1_der_coding(src, src_name, data, &size, NULL);
 135
 136   res->data = (unsigned char *)data;
 137   res->size = size;
 138 }
 139
 140
 141 static void
 142 test_tls_get_ipaddr(const char *addrstr,
 143                     char **data,
 144                     int *datalen)
 145 {
 146     struct addrinfo *res;
 147     struct addrinfo hints;
 148
 149     memset(&hints, 0, sizeof(hints));
 150     hints.ai_flags = AI_NUMERICHOST;
 151     g_assert(getaddrinfo(addrstr, NULL, &hints, &res) == 0);
 152
 153     *datalen = res->ai_addrlen;
 154     *data = g_new(char, *datalen);
 155     memcpy(*data, res->ai_addr, *datalen);
 156     freeaddrinfo(res);
 157 }
 158
 159 /*
 160  * This is a fairly lame x509 certificate generator.
 161  *
 162  * Do not copy/use this code for generating real certificates
 163  * since it leaves out many things that you would want in
 164  * certificates for real world usage.
 165  *
 166  * This is good enough only for doing tests of the QEMU
 167  * TLS certificate code
 168  */
 169 void
 170 test_tls_generate_cert(QCryptoTLSTestCertReq *req,
 171                        gnutls_x509_crt_t ca)
 172 {
 173     gnutls_x509_crt_t crt;
 174     int err;
 175     static char buffer[1024 * 1024];
 176     size_t size = sizeof(buffer);
 177     char serial[5] = { 1, 2, 3, 4, 0 };
 178     gnutls_datum_t der;
 179     time_t start = time(NULL) + (60 * 60 * req->start_offset);
 180     time_t expire = time(NULL) + (60 * 60 * (req->expire_offset
 181                                              ? req->expire_offset : 24));
 182
 183     /*
 184      * Prepare our new certificate object
 185      */
 186     err = gnutls_x509_crt_init(&crt);
 187     if (err < 0) {
 188         g_critical("Failed to initialize certificate %s", gnutls_strerror(err));
 189         abort();
 190     }
 191     err = gnutls_x509_crt_set_key(crt, privkey);
 192     if (err < 0) {
 193         g_critical("Failed to set certificate key %s", gnutls_strerror(err));
 194         abort();
 195     }
 196
 197     /*
 198      * A v3 certificate is required in order to be able
 199      * set any of the basic constraints, key purpose and
 200      * key usage data
 201      */
 202     gnutls_x509_crt_set_version(crt, 3);
 203
 204     if (req->country) {
 205         err = gnutls_x509_crt_set_dn_by_oid(
 206             crt, GNUTLS_OID_X520_COUNTRY_NAME, 0,
 207             req->country, strlen(req->country));
 208         if (err < 0) {
 209             g_critical("Failed to set certificate country name %s",
 210                        gnutls_strerror(err));
 211             abort();
 212         }
 213     }
 214     if (req->cn) {
 215         err = gnutls_x509_crt_set_dn_by_oid(
 216             crt, GNUTLS_OID_X520_COMMON_NAME, 0,
 217             req->cn, strlen(req->cn));
 218         if (err < 0) {
 219             g_critical("Failed to set certificate common name %s",
 220                        gnutls_strerror(err));
 221             abort();
 222         }
 223     }
 224
 225     /*
 226      * Setup the subject altnames, which are used
 227      * for hostname checks in live sessions
 228      */
 229     if (req->altname1) {
 230         err = gnutls_x509_crt_set_subject_alt_name(
 231             crt, GNUTLS_SAN_DNSNAME,
 232             req->altname1,
 233             strlen(req->altname1),
 234             GNUTLS_FSAN_APPEND);
 235         if (err < 0) {
 236             g_critical("Failed to set certificate alt name %s",
 237                        gnutls_strerror(err));
 238             abort();
 239         }
 240     }
 241     if (req->altname2) {
 242         err = gnutls_x509_crt_set_subject_alt_name(
 243             crt, GNUTLS_SAN_DNSNAME,
 244             req->altname2,
 245             strlen(req->altname2),
 246             GNUTLS_FSAN_APPEND);
 247         if (err < 0) {
 248             g_critical("Failed to set certificate %s alt name",
 249                        gnutls_strerror(err));
 250             abort();
 251         }
 252     }
 253
 254     /*
 255      * IP address need to be put into the cert in their
 256      * raw byte form, not strings, hence this is a little
 257      * more complicated
 258      */
 259     if (req->ipaddr1) {
 260         char *data;
 261         int len;
 262
 263         test_tls_get_ipaddr(req->ipaddr1, &data, &len);
 264
 265         err = gnutls_x509_crt_set_subject_alt_name(
 266             crt, GNUTLS_SAN_IPADDRESS,
 267             data, len, GNUTLS_FSAN_APPEND);
 268         if (err < 0) {
 269             g_critical("Failed to set certificate alt name %s",
 270                        gnutls_strerror(err));
 271             abort();
 272         }
 273         g_free(data);
 274     }
 275     if (req->ipaddr2) {
 276         char *data;
 277         int len;
 278
 279         test_tls_get_ipaddr(req->ipaddr2, &data, &len);
 280
 281         err = gnutls_x509_crt_set_subject_alt_name(
 282             crt, GNUTLS_SAN_IPADDRESS,
 283             data, len, GNUTLS_FSAN_APPEND);
 284         if (err < 0) {
 285             g_critical("Failed to set certificate alt name %s",
 286                        gnutls_strerror(err));
 287             abort();
 288         }
 289         g_free(data);
 290     }
 291
 292
 293     /*
 294      * Basic constraints are used to decide if the cert
 295      * is for a CA or not. We can't use the convenient
 296      * gnutls API for setting this, since it hardcodes
 297      * the 'critical' field which we want control over
 298      */
 299     if (req->basicConstraintsEnable) {
 300         ASN1_TYPE ext = ASN1_TYPE_EMPTY;
 301
 302         asn1_create_element(pkix_asn1, "PKIX1.BasicConstraints", &ext);
 303         asn1_write_value(ext, "cA",
 304                          req->basicConstraintsIsCA ? "TRUE" : "FALSE", 1);
 305         asn1_write_value(ext, "pathLenConstraint", NULL, 0);
 306         test_tls_der_encode(ext, "", &der);
 307         err = gnutls_x509_crt_set_extension_by_oid(
 308             crt, "2.5.29.19",
 309             der.data, der.size,
 310             req->basicConstraintsCritical);
 311         if (err < 0) {
 312             g_critical("Failed to set certificate basic constraints %s",
 313                        gnutls_strerror(err));
 314             g_free(der.data);
 315             abort();
 316         }
 317         asn1_delete_structure(&ext);
 318         g_free(der.data);
 319     }
 320
 321     /*
 322      * Next up the key usage extension. Again we can't
 323      * use the gnutls API since it hardcodes the extension
 324      * to be 'critical'
 325      */
 326     if (req->keyUsageEnable) {
 327         ASN1_TYPE ext = ASN1_TYPE_EMPTY;
 328         char str[2];
 329
 330         str[0] = req->keyUsageValue & 0xff;
 331         str[1] = (req->keyUsageValue >> 8) & 0xff;
 332
 333         asn1_create_element(pkix_asn1, "PKIX1.KeyUsage", &ext);
 334         asn1_write_value(ext, "", str, 9);
 335         test_tls_der_encode(ext, "", &der);
 336         err = gnutls_x509_crt_set_extension_by_oid(
 337             crt, "2.5.29.15",
 338             der.data, der.size,
 339             req->keyUsageCritical);
 340         if (err < 0) {
 341             g_critical("Failed to set certificate key usage %s",
 342                        gnutls_strerror(err));
 343             g_free(der.data);
 344             abort();
 345         }
 346         asn1_delete_structure(&ext);
 347         g_free(der.data);
 348     }
 349
 350     /*
 351      * Finally the key purpose extension. This time
 352      * gnutls has the opposite problem, always hardcoding
 353      * it to be non-critical. So once again we have to
 354      * set this the hard way building up ASN1 data ourselves
 355      */
 356     if (req->keyPurposeEnable) {
 357         ASN1_TYPE ext = ASN1_TYPE_EMPTY;
 358
 359         asn1_create_element(pkix_asn1, "PKIX1.ExtKeyUsageSyntax", &ext);
 360         if (req->keyPurposeOID1) {
 361             asn1_write_value(ext, "", "NEW", 1);
 362             asn1_write_value(ext, "?LAST", req->keyPurposeOID1, 1);
 363         }
 364         if (req->keyPurposeOID2) {
 365             asn1_write_value(ext, "", "NEW", 1);
 366             asn1_write_value(ext, "?LAST", req->keyPurposeOID2, 1);
 367         }
 368         test_tls_der_encode(ext, "", &der);
 369         err = gnutls_x509_crt_set_extension_by_oid(
 370             crt, "2.5.29.37",
 371             der.data, der.size,
 372             req->keyPurposeCritical);
 373         if (err < 0) {
 374             g_critical("Failed to set certificate key purpose %s",
 375                        gnutls_strerror(err));
 376             g_free(der.data);
 377             abort();
 378         }
 379         asn1_delete_structure(&ext);
 380         g_free(der.data);
 381     }
 382
 383     /*
 384      * Any old serial number will do, so lets pick 5
 385      */
 386     err = gnutls_x509_crt_set_serial(crt, serial, 5);
 387     if (err < 0) {
 388         g_critical("Failed to set certificate serial %s",
 389                    gnutls_strerror(err));
 390         abort();
 391     }
 392
 393     err = gnutls_x509_crt_set_activation_time(crt, start);
 394     if (err < 0) {
 395         g_critical("Failed to set certificate activation %s",
 396                    gnutls_strerror(err));
 397         abort();
 398     }
 399     err = gnutls_x509_crt_set_expiration_time(crt, expire);
 400     if (err < 0) {
 401         g_critical("Failed to set certificate expiration %s",
 402                    gnutls_strerror(err));
 403         abort();
 404     }
 405
 406
 407     /*
 408      * If no 'ca' is set then we are self signing
 409      * the cert. This is done for the root CA certs
 410      */
 411     err = gnutls_x509_crt_sign(crt, ca ? ca : crt, privkey);
 412     if (err < 0) {
 413         g_critical("Failed to sign certificate %s",
 414                    gnutls_strerror(err));
 415         abort();
 416     }
 417
 418     /*
 419      * Finally write the new cert out to disk
 420      */
 421     err = gnutls_x509_crt_export(
 422         crt, GNUTLS_X509_FMT_PEM, buffer, &size);
 423     if (err < 0) {
 424         g_critical("Failed to export certificate %s: %d",
 425                    gnutls_strerror(err), err);
 426         abort();
 427     }
 428
 429     if (!g_file_set_contents(req->filename, buffer, -1, NULL)) {
 430         g_critical("Failed to write certificate %s",
 431                    req->filename);
 432         abort();
 433     }
 434
 435     req->crt = crt;
 436 }
 437
 438
 439 void test_tls_write_cert_chain(const char *filename,
 440                                gnutls_x509_crt_t *certs,
 441                                size_t ncerts)
 442 {
 443     size_t i;
 444     size_t capacity = 1024, offset = 0;
 445     char *buffer = g_new0(char, capacity);
 446     int err;
 447
 448     for (i = 0; i < ncerts; i++) {
 449         size_t len = capacity - offset;
 450     retry:
 451         err = gnutls_x509_crt_export(certs[i], GNUTLS_X509_FMT_PEM,
 452                                      buffer + offset, &len);
 453         if (err < 0) {
 454             if (err == GNUTLS_E_SHORT_MEMORY_BUFFER) {
 455                 buffer = g_renew(char, buffer, offset + len);
 456                 capacity = offset + len;
 457                 goto retry;
 458             }
 459             g_critical("Failed to export certificate chain %s: %d",
 460                        gnutls_strerror(err), err);
 461             abort();
 462         }
 463         offset += len;
 464     }
 465
 466     if (!g_file_set_contents(filename, buffer, offset, NULL)) {
 467         abort();
 468     }
 469     g_free(buffer);
 470 }
 471
 472
 473 void test_tls_discard_cert(QCryptoTLSTestCertReq *req)
 474 {
 475     if (!req->crt) {
 476         return;
 477     }
 478
 479     gnutls_x509_crt_deinit(req->crt);
 480     req->crt = NULL;
 481
 482     if (getenv("QEMU_TEST_DEBUG_CERTS") == NULL) {
 483         unlink(req->filename);
 484     }
 485 }
 486
 487 #endif /* QCRYPTO_HAVE_TLS_TEST_SUPPORT */