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