test/heartbeat_test.c

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