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 "../ssl/ssl_locl.h"
  44
  45 #include "testutil.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[MAX_PRINTABLE_CHARACTERS+4] =
 280                 "   Not bleeding, sixteen spaces of padding"
 281                 "                ";
 282         const int payload_buf_len = honest_payload_size(payload_buf);
 283
 284         fixture.payload = &payload_buf[0];
 285         fixture.sent_payload_len = payload_buf_len;
 286         fixture.expected_return_value = 0;
 287         fixture.expected_payload_len = payload_buf_len;
 288         fixture.expected_return_payload = "Not bleeding, sixteen spaces of padding";
 289         EXECUTE_HEARTBEAT_TEST();
 290         }
 291
 292 static int test_dtls1_not_bleeding_empty_payload()
 293         {
 294         int payload_buf_len;
 295
 296         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 297         /* Three-byte pad at the beginning for type and payload length, plus a NUL
 298          * at the end */
 299         unsigned char payload_buf[4 + MAX_PRINTABLE_CHARACTERS];
 300         memset(payload_buf, ' ', MIN_PADDING_SIZE+3);
 301         payload_buf[MIN_PADDING_SIZE+3] = '\0';
 302         payload_buf_len = honest_payload_size(payload_buf);
 303
 304         fixture.payload = &payload_buf[0];
 305         fixture.sent_payload_len = payload_buf_len;
 306         fixture.expected_return_value = 0;
 307         fixture.expected_payload_len = payload_buf_len;
 308         fixture.expected_return_payload = "";
 309         EXECUTE_HEARTBEAT_TEST();
 310         }
 311
 312 static int test_dtls1_heartbleed()
 313         {
 314         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 315         /* Three-byte pad at the beginning for type and payload length */
 316         unsigned char payload_buf[4+MAX_PRINTABLE_CHARACTERS] =
 317                 "   HEARTBLEED                ";
 318
 319         fixture.payload = &payload_buf[0];
 320         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 321         fixture.expected_return_value = 0;
 322         fixture.expected_payload_len = 0;
 323         fixture.expected_return_payload = "";
 324         EXECUTE_HEARTBEAT_TEST();
 325         }
 326
 327 static int test_dtls1_heartbleed_empty_payload()
 328         {
 329         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 330         /* Excluding the NUL at the end, one byte short of type + payload length +
 331          * minimum padding */
 332         unsigned char payload_buf[MAX_PRINTABLE_CHARACTERS + 4];
 333         memset(payload_buf, ' ', MIN_PADDING_SIZE+2);
 334         payload_buf[MIN_PADDING_SIZE+2] = '\0';
 335
 336         fixture.payload = &payload_buf[0];
 337         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 338         fixture.expected_return_value = 0;
 339         fixture.expected_payload_len = 0;
 340         fixture.expected_return_payload = "";
 341         EXECUTE_HEARTBEAT_TEST();
 342         }
 343
 344 static int test_dtls1_heartbleed_excessive_plaintext_length()
 345         {
 346         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 347         /* Excluding the NUL at the end, one byte in excess of maximum allowed
 348          * heartbeat message length */
 349         unsigned char payload_buf[SSL3_RT_MAX_PLAIN_LENGTH + 2];
 350         memset(payload_buf, ' ', sizeof(payload_buf));
 351         payload_buf[sizeof(payload_buf) - 1] = '\0';
 352
 353         fixture.payload = &payload_buf[0];
 354         fixture.sent_payload_len = honest_payload_size(payload_buf);
 355         fixture.expected_return_value = 0;
 356         fixture.expected_payload_len = 0;
 357         fixture.expected_return_payload = "";
 358         EXECUTE_HEARTBEAT_TEST();
 359         }
 360
 361 static int test_tls1_not_bleeding()
 362         {
 363         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 364         /* Three-byte pad at the beginning for type and payload length */
 365         unsigned char payload_buf[MAX_PRINTABLE_CHARACTERS+4] =
 366                         "   Not bleeding, sixteen spaces of padding"
 367                         "                ";
 368         const int payload_buf_len = honest_payload_size(payload_buf);
 369
 370         fixture.payload = &payload_buf[0];
 371         fixture.sent_payload_len = payload_buf_len;
 372         fixture.expected_return_value = 0;
 373         fixture.expected_payload_len = payload_buf_len;
 374         fixture.expected_return_payload = "Not bleeding, sixteen spaces of padding";
 375         EXECUTE_HEARTBEAT_TEST();
 376         }
 377
 378 static int test_tls1_not_bleeding_empty_payload()
 379         {
 380         int payload_buf_len;
 381
 382         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 383         /* Three-byte pad at the beginning for type and payload length, plus a NUL
 384          * at the end */
 385         unsigned char payload_buf[4 + MAX_PRINTABLE_CHARACTERS];
 386         memset(payload_buf, ' ', MIN_PADDING_SIZE+3);
 387         payload_buf[MIN_PADDING_SIZE+3] = '\0';
 388         payload_buf_len = honest_payload_size(payload_buf);
 389
 390         fixture.payload = &payload_buf[0];
 391         fixture.sent_payload_len = payload_buf_len;
 392         fixture.expected_return_value = 0;
 393         fixture.expected_payload_len = payload_buf_len;
 394         fixture.expected_return_payload = "";
 395         EXECUTE_HEARTBEAT_TEST();
 396         }
 397
 398 static int test_tls1_heartbleed()
 399         {
 400         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 401         /* Three-byte pad at the beginning for type and payload length */
 402         unsigned char payload_buf[MAX_PRINTABLE_CHARACTERS+4] =
 403                         "   HEARTBLEED                ";
 404
 405         fixture.payload = &payload_buf[0];
 406         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 407         fixture.expected_return_value = 0;
 408         fixture.expected_payload_len = 0;
 409         fixture.expected_return_payload = "";
 410         EXECUTE_HEARTBEAT_TEST();
 411         }
 412
 413 static int test_tls1_heartbleed_empty_payload()
 414         {
 415         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 416         /* Excluding the NUL at the end, one byte short of type + payload length +
 417          * minimum padding */
 418         unsigned char payload_buf[MAX_PRINTABLE_CHARACTERS + 4];
 419         memset(payload_buf, ' ', MIN_PADDING_SIZE+2);
 420         payload_buf[MIN_PADDING_SIZE+2] = '\0';
 421
 422         fixture.payload = &payload_buf[0];
 423         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 424         fixture.expected_return_value = 0;
 425         fixture.expected_payload_len = 0;
 426         fixture.expected_return_payload = "";
 427         EXECUTE_HEARTBEAT_TEST();
 428         }
 429
 430 #undef EXECUTE_HEARTBEAT_TEST
 431 #undef SETUP_HEARTBEAT_TEST_FIXTURE
 432
 433 int main(int argc, char *argv[])
 434         {
 435         int result = 0;
 436
 437         SSL_library_init();
 438         SSL_load_error_strings();
 439
 440         ADD_TEST(test_dtls1_not_bleeding);
 441         ADD_TEST(test_dtls1_not_bleeding_empty_payload);
 442         ADD_TEST(test_dtls1_heartbleed);
 443         ADD_TEST(test_dtls1_heartbleed_empty_payload);
 444         ADD_TEST(test_dtls1_heartbleed_excessive_plaintext_length);
 445         ADD_TEST(test_tls1_not_bleeding);
 446         ADD_TEST(test_tls1_not_bleeding_empty_payload);
 447         ADD_TEST(test_tls1_heartbleed);
 448         ADD_TEST(test_tls1_heartbleed_empty_payload);
 449
 450         result = run_tests(argv[0]);
 451         ERR_print_errors_fp(stderr);
 452         return result;
 453         }
 454
 455 #else /* OPENSSL_NO_HEARTBEATS*/
 456
 457 int main(int argc, char *argv[])
 458         {
 459                 return EXIT_SUCCESS;
 460         }
 461 #endif /* OPENSSL_NO_HEARTBEATS */