ssl/heartbeat_test.c

   1 /* test/heartbeat_test.c */
   2 /*-
   3  * Unit test for TLS heartbeats.
   4  *
   5  * Acts as a regression test against the Heartbleed bug (CVE-2014-0160).
   6  *
   7  * Author:  Mike Bland (mbland@acm.org, http://mike-bland.com/)
   8  * Date:    2014-04-12
   9  * License: Creative Commons Attribution 4.0 International (CC By 4.0)
  10  *          http://creativecommons.org/licenses/by/4.0/deed.en_US
  11  *
  12  * OUTPUT
  13  * ------
  14  * The program returns zero on success. It will print a message with a count
  15  * of the number of failed tests and return nonzero if any tests fail.
  16  *
  17  * It will print the contents of the request and response buffers for each
  18  * failing test. In a "fixed" version, all the tests should pass and there
  19  * should be no output.
  20  *
  21  * In a "bleeding" version, you'll see:
  22  *
  23  *   test_dtls1_heartbleed failed:
  24  *     expected payload len: 0
  25  *     received: 1024
  26  *   sent 26 characters
  27  *     "HEARTBLEED                "
  28  *   received 1024 characters
  29  *     "HEARTBLEED                \xde\xad\xbe\xef..."
  30  *   ** test_dtls1_heartbleed failed **
  31  *
  32  * The contents of the returned buffer in the failing test will depend on the
  33  * contents of memory on your machine.
  34  *
  35  * MORE INFORMATION
  36  * ----------------
  37  * http://mike-bland.com/2014/04/12/heartbleed.html
  38  * http://mike-bland.com/tags/heartbleed.html
  39  */
  40
  41 #define OPENSSL_UNIT_TEST
  42
  43 #include "../test/testutil.h"
  44
  45 #include "../ssl/ssl_locl.h"
  46 #include <ctype.h>
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50
  51 #if !defined(OPENSSL_NO_HEARTBEATS) && !defined(OPENSSL_NO_UNIT_TEST)
  52
  53 /* As per https://tools.ietf.org/html/rfc6520#section-4 */
  54 #define MIN_PADDING_SIZE        16
  55
  56 /* Maximum number of payload characters to print as test output */
  57 #define MAX_PRINTABLE_CHARACTERS        1024
  58
  59 typedef struct heartbeat_test_fixture
  60         {
  61         SSL_CTX *ctx;
  62         SSL *s;
  63         const char* test_case_name;
  64         int (*process_heartbeat)(SSL* s);
  65         unsigned char* payload;
  66         int sent_payload_len;
  67         int expected_return_value;
  68         int return_payload_offset;
  69         int expected_payload_len;
  70         const char* expected_return_payload;
  71         } HEARTBEAT_TEST_FIXTURE;
  72
  73 static HEARTBEAT_TEST_FIXTURE set_up(const char* const test_case_name,
  74         const SSL_METHOD* meth)
  75         {
  76         HEARTBEAT_TEST_FIXTURE fixture;
  77         int setup_ok = 1;
  78         memset(&fixture, 0, sizeof(fixture));
  79         fixture.test_case_name = test_case_name;
  80
  81         fixture.ctx = SSL_CTX_new(meth);
  82         if (!fixture.ctx)
  83                 {
  84                 fprintf(stderr, "Failed to allocate SSL_CTX for test: %s\n",
  85                         test_case_name);
  86                 setup_ok = 0;
  87                 goto fail;
  88                 }
  89
  90         fixture.s = SSL_new(fixture.ctx);
  91         if (!fixture.s)
  92                 {
  93                 fprintf(stderr, "Failed to allocate SSL for test: %s\n", test_case_name);
  94                 setup_ok = 0;
  95                 goto fail;
  96                 }
  97
  98         if (!ssl_init_wbio_buffer(fixture.s, 1))
  99                 {
 100                 fprintf(stderr, "Failed to set up wbio buffer for test: %s\n",
 101                         test_case_name);
 102                 setup_ok = 0;
 103                 goto fail;
 104                 }
 105
 106         if (!ssl3_setup_buffers(fixture.s))
 107                 {
 108                 fprintf(stderr, "Failed to setup buffers for test: %s\n",
 109                         test_case_name);
 110                 setup_ok = 0;
 111                 goto fail;
 112                 }
 113
 114         /* Clear the memory for the return buffer, since this isn't automatically
 115          * zeroed in opt mode and will cause spurious test failures that will change
 116          * with each execution.
 117          */
 118         memset(fixture.s->s3->wbuf.buf, 0, fixture.s->s3->wbuf.len);
 119
 120         fail:
 121         if (!setup_ok)
 122                 {
 123                 ERR_print_errors_fp(stderr);
 124                 exit(EXIT_FAILURE);
 125                 }
 126         return fixture;
 127         }
 128
 129 static HEARTBEAT_TEST_FIXTURE set_up_dtls(const char* const test_case_name)
 130         {
 131         HEARTBEAT_TEST_FIXTURE fixture = set_up(test_case_name,
 132                 DTLSv1_server_method());
 133         fixture.process_heartbeat = dtls1_process_heartbeat;
 134
 135         /* As per dtls1_get_record(), skipping the following from the beginning of
 136          * the returned heartbeat message:
 137          * type-1 byte; version-2 bytes; sequence number-8 bytes; length-2 bytes
 138          *
 139          * And then skipping the 1-byte type encoded by process_heartbeat for
 140          * a total of 14 bytes, at which point we can grab the length and the
 141          * payload we seek.
 142          */
 143         fixture.return_payload_offset = 14;
 144         return fixture;
 145         }
 146
 147 /* Needed by ssl3_write_bytes() */
 148 static int dummy_handshake(SSL* s)
 149         {
 150         return 1;
 151         }
 152
 153 static HEARTBEAT_TEST_FIXTURE set_up_tls(const char* const test_case_name)
 154         {
 155         HEARTBEAT_TEST_FIXTURE fixture = set_up(test_case_name,
 156                 TLSv1_server_method());
 157         fixture.process_heartbeat = tls1_process_heartbeat;
 158         fixture.s->handshake_func = dummy_handshake;
 159
 160         /* As per do_ssl3_write(), skipping the following from the beginning of
 161          * the returned heartbeat message:
 162          * type-1 byte; version-2 bytes; length-2 bytes
 163          *
 164          * And then skipping the 1-byte type encoded by process_heartbeat for
 165          * a total of 6 bytes, at which point we can grab the length and the payload
 166          * we seek.
 167          */
 168         fixture.return_payload_offset = 6;
 169         return fixture;
 170         }
 171
 172 static void tear_down(HEARTBEAT_TEST_FIXTURE fixture)
 173         {
 174         ERR_print_errors_fp(stderr);
 175         SSL_free(fixture.s);
 176         SSL_CTX_free(fixture.ctx);
 177         }
 178
 179 static void print_payload(const char* const prefix,
 180                 const unsigned char *payload, const int n)
 181         {
 182         const int end = n < MAX_PRINTABLE_CHARACTERS ? n
 183             : MAX_PRINTABLE_CHARACTERS;
 184         int i = 0;
 185
 186         printf("%s %d character%s", prefix, n, n == 1 ? "" : "s");
 187         if (end != n) printf(" (first %d shown)", end);
 188         printf("\n  \"");
 189
 190         for (; i != end; ++i)
 191                 {
 192                 const unsigned char c = payload[i];
 193                 if (isprint(c)) fputc(c, stdout);
 194                 else printf("\\x%02x", c);
 195                 }
 196         printf("\"\n");
 197         }
 198
 199 static int execute_heartbeat(HEARTBEAT_TEST_FIXTURE fixture)
 200         {
 201         int result = 0;
 202         SSL* s = fixture.s;
 203         unsigned char *payload = fixture.payload;
 204         unsigned char sent_buf[MAX_PRINTABLE_CHARACTERS + 1];
 205         int return_value;
 206         unsigned const char *p;
 207         int actual_payload_len;
 208
 209         s->s3->rrec.data = payload;
 210         s->s3->rrec.length = strlen((const char*)payload);
 211         *payload++ = TLS1_HB_REQUEST;
 212         s2n(fixture.sent_payload_len, payload);
 213
 214         /* Make a local copy of the request, since it gets overwritten at some
 215          * point */
 216         memcpy((char *)sent_buf, (const char*)payload, sizeof(sent_buf));
 217
 218         return_value = fixture.process_heartbeat(s);
 219
 220         if (return_value != fixture.expected_return_value)
 221                 {
 222                 printf("%s failed: expected return value %d, received %d\n",
 223                                          fixture.test_case_name, fixture.expected_return_value,
 224                                          return_value);
 225                 result = 1;
 226                 }
 227
 228         /* If there is any byte alignment, it will be stored in wbuf.offset. */
 229         p = &(s->s3->wbuf.buf[
 230                         fixture.return_payload_offset + s->s3->wbuf.offset]);
 231         actual_payload_len = 0;
 232         n2s(p, actual_payload_len);
 233
 234         if (actual_payload_len != fixture.expected_payload_len)
 235                 {
 236                 printf("%s failed:\n  expected payload len: %d\n  received: %d\n",
 237                                          fixture.test_case_name, fixture.expected_payload_len,
 238                                          actual_payload_len);
 239                 print_payload("sent", sent_buf, strlen((const char*)sent_buf));
 240                 print_payload("received", p, actual_payload_len);
 241                 result = 1;
 242                 }
 243         else
 244                 {
 245                 char* actual_payload = BUF_strndup((const char*)p, actual_payload_len);
 246                 if (strcmp(actual_payload, fixture.expected_return_payload) != 0)
 247                         {
 248                         printf("%s failed:\n  expected payload: \"%s\"\n  received: \"%s\"\n",
 249                                                  fixture.test_case_name, fixture.expected_return_payload,
 250                                                  actual_payload);
 251                         result = 1;
 252                         }
 253                 OPENSSL_free(actual_payload);
 254                 }
 255
 256         if (result != 0)
 257                 {
 258                 printf("** %s failed **\n--------\n", fixture.test_case_name);
 259                 }
 260         return result;
 261         }
 262
 263 static int honest_payload_size(unsigned char payload_buf[])
 264         {
 265         /* Omit three-byte pad at the beginning for type and payload length */
 266         return strlen((const char*)&payload_buf[3]) - MIN_PADDING_SIZE;
 267         }
 268
 269 #define SETUP_HEARTBEAT_TEST_FIXTURE(type)\
 270   SETUP_TEST_FIXTURE(HEARTBEAT_TEST_FIXTURE, set_up_##type)
 271
 272 #define EXECUTE_HEARTBEAT_TEST()\
 273   EXECUTE_TEST(execute_heartbeat, tear_down)
 274
 275 static int test_dtls1_not_bleeding()
 276         {
 277         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 278         /* Three-byte pad at the beginning for type and payload length */
 279         unsigned char payload_buf[] = "   Not bleeding, sixteen spaces of padding"
 280                 "                ";
 281         const int payload_buf_len = honest_payload_size(payload_buf);
 282
 283         fixture.payload = &payload_buf[0];
 284         fixture.sent_payload_len = payload_buf_len;
 285         fixture.expected_return_value = 0;
 286         fixture.expected_payload_len = payload_buf_len;
 287         fixture.expected_return_payload = "Not bleeding, sixteen spaces of padding";
 288         EXECUTE_HEARTBEAT_TEST();
 289         }
 290
 291 static int test_dtls1_not_bleeding_empty_payload()
 292         {
 293         int payload_buf_len;
 294
 295         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 296         /* Three-byte pad at the beginning for type and payload length, plus a NUL
 297          * at the end */
 298         unsigned char payload_buf[4 + MIN_PADDING_SIZE];
 299         memset(payload_buf, ' ', sizeof(payload_buf));
 300         payload_buf[sizeof(payload_buf) - 1] = '\0';
 301         payload_buf_len = honest_payload_size(payload_buf);
 302
 303         fixture.payload = &payload_buf[0];
 304         fixture.sent_payload_len = payload_buf_len;
 305         fixture.expected_return_value = 0;
 306         fixture.expected_payload_len = payload_buf_len;
 307         fixture.expected_return_payload = "";
 308         EXECUTE_HEARTBEAT_TEST();
 309         }
 310
 311 static int test_dtls1_heartbleed()
 312         {
 313         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 314         /* Three-byte pad at the beginning for type and payload length */
 315         unsigned char payload_buf[] = "   HEARTBLEED                ";
 316
 317         fixture.payload = &payload_buf[0];
 318         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 319         fixture.expected_return_value = 0;
 320         fixture.expected_payload_len = 0;
 321         fixture.expected_return_payload = "";
 322         EXECUTE_HEARTBEAT_TEST();
 323         }
 324
 325 static int test_dtls1_heartbleed_empty_payload()
 326         {
 327         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 328         /* Excluding the NUL at the end, one byte short of type + payload length +
 329          * minimum padding */
 330         unsigned char payload_buf[MIN_PADDING_SIZE + 3];
 331         memset(payload_buf, ' ', sizeof(payload_buf));
 332         payload_buf[sizeof(payload_buf) - 1] = '\0';
 333
 334         fixture.payload = &payload_buf[0];
 335         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 336         fixture.expected_return_value = 0;
 337         fixture.expected_payload_len = 0;
 338         fixture.expected_return_payload = "";
 339         EXECUTE_HEARTBEAT_TEST();
 340         }
 341
 342 static int test_dtls1_heartbleed_excessive_plaintext_length()
 343         {
 344         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 345         /* Excluding the NUL at the end, one byte in excess of maximum allowed
 346          * heartbeat message length */
 347         unsigned char payload_buf[SSL3_RT_MAX_PLAIN_LENGTH + 2];
 348         memset(payload_buf, ' ', sizeof(payload_buf));
 349         payload_buf[sizeof(payload_buf) - 1] = '\0';
 350
 351         fixture.payload = &payload_buf[0];
 352         fixture.sent_payload_len = honest_payload_size(payload_buf);
 353         fixture.expected_return_value = 0;
 354         fixture.expected_payload_len = 0;
 355         fixture.expected_return_payload = "";
 356         EXECUTE_HEARTBEAT_TEST();
 357         }
 358
 359 static int test_tls1_not_bleeding()
 360         {
 361         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 362         /* Three-byte pad at the beginning for type and payload length */
 363         unsigned char payload_buf[] = "   Not bleeding, sixteen spaces of padding"
 364                                         "                ";
 365         const int payload_buf_len = honest_payload_size(payload_buf);
 366
 367         fixture.payload = &payload_buf[0];
 368         fixture.sent_payload_len = payload_buf_len;
 369         fixture.expected_return_value = 0;
 370         fixture.expected_payload_len = payload_buf_len;
 371         fixture.expected_return_payload = "Not bleeding, sixteen spaces of padding";
 372         EXECUTE_HEARTBEAT_TEST();
 373         }
 374
 375 static int test_tls1_not_bleeding_empty_payload()
 376         {
 377         int payload_buf_len;
 378
 379         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 380         /* Three-byte pad at the beginning for type and payload length, plus a NUL
 381          * at the end */
 382         unsigned char payload_buf[4 + MIN_PADDING_SIZE];
 383         memset(payload_buf, ' ', sizeof(payload_buf));
 384         payload_buf[sizeof(payload_buf) - 1] = '\0';
 385         payload_buf_len = honest_payload_size(payload_buf);
 386
 387         fixture.payload = &payload_buf[0];
 388         fixture.sent_payload_len = payload_buf_len;
 389         fixture.expected_return_value = 0;
 390         fixture.expected_payload_len = payload_buf_len;
 391         fixture.expected_return_payload = "";
 392         EXECUTE_HEARTBEAT_TEST();
 393         }
 394
 395 static int test_tls1_heartbleed()
 396         {
 397         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 398         /* Three-byte pad at the beginning for type and payload length */
 399         unsigned char payload_buf[] = "   HEARTBLEED                ";
 400
 401         fixture.payload = &payload_buf[0];
 402         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 403         fixture.expected_return_value = 0;
 404         fixture.expected_payload_len = 0;
 405         fixture.expected_return_payload = "";
 406         EXECUTE_HEARTBEAT_TEST();
 407         }
 408
 409 static int test_tls1_heartbleed_empty_payload()
 410         {
 411         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 412         /* Excluding the NUL at the end, one byte short of type + payload length +
 413          * minimum padding */
 414         unsigned char payload_buf[MIN_PADDING_SIZE + 3];
 415         memset(payload_buf, ' ', sizeof(payload_buf));
 416         payload_buf[sizeof(payload_buf) - 1] = '\0';
 417
 418         fixture.payload = &payload_buf[0];
 419         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 420         fixture.expected_return_value = 0;
 421         fixture.expected_payload_len = 0;
 422         fixture.expected_return_payload = "";
 423         EXECUTE_HEARTBEAT_TEST();
 424         }
 425
 426 #undef EXECUTE_HEARTBEAT_TEST
 427 #undef SETUP_HEARTBEAT_TEST_FIXTURE
 428
 429 int main(int argc, char *argv[])
 430         {
 431         int num_failed;
 432
 433         SSL_library_init();
 434         SSL_load_error_strings();
 435
 436         num_failed = test_dtls1_not_bleeding() +
 437             test_dtls1_not_bleeding_empty_payload() +
 438             test_dtls1_heartbleed() +
 439             test_dtls1_heartbleed_empty_payload() +
 440             /* The following test causes an assertion failure at
 441              * ssl/d1_pkt.c:dtls1_write_bytes() in versions prior to 1.0.1g: */
 442             (OPENSSL_VERSION_NUMBER >= 0x1000107fL ?
 443              test_dtls1_heartbleed_excessive_plaintext_length() : 0) +
 444             test_tls1_not_bleeding() +
 445             test_tls1_not_bleeding_empty_payload() +
 446             test_tls1_heartbleed() +
 447             test_tls1_heartbleed_empty_payload() +
 448             0;
 449
 450         ERR_print_errors_fp(stderr);
 451
 452         if (num_failed != 0)
 453                 {
 454                 printf("%d test%s failed\n", num_failed, num_failed != 1 ? "s" : "");
 455                 return EXIT_FAILURE;
 456                 }
 457         return EXIT_SUCCESS;
 458         }
 459
 460 #else /* OPENSSL_NO_HEARTBEATS*/
 461
 462 int main(int argc, char *argv[])
 463         {
 464                 return EXIT_SUCCESS;
 465         }
 466 #endif /* OPENSSL_NO_HEARTBEATS */