test/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     SSL_CTX *ctx;
  61     SSL *s;
  62     const char *test_case_name;
  63     int (*process_heartbeat) (SSL *s, unsigned char *p, unsigned int length);
  64     unsigned char *payload;
  65     int sent_payload_len;
  66     int expected_return_value;
  67     int return_payload_offset;
  68     int expected_payload_len;
  69     const char *expected_return_payload;
  70 } HEARTBEAT_TEST_FIXTURE;
  71
  72 static HEARTBEAT_TEST_FIXTURE set_up(const char *const test_case_name,
  73                                      const SSL_METHOD *meth)
  74 {
  75     HEARTBEAT_TEST_FIXTURE fixture;
  76     int setup_ok = 1;
  77     memset(&fixture, 0, sizeof(fixture));
  78     fixture.test_case_name = test_case_name;
  79
  80     fixture.ctx = SSL_CTX_new(meth);
  81     if (!fixture.ctx) {
  82         fprintf(stderr, "Failed to allocate SSL_CTX for test: %s\n",
  83                 test_case_name);
  84         setup_ok = 0;
  85         goto fail;
  86     }
  87
  88     fixture.s = SSL_new(fixture.ctx);
  89     if (!fixture.s) {
  90         fprintf(stderr, "Failed to allocate SSL for test: %s\n",
  91                 test_case_name);
  92         setup_ok = 0;
  93         goto fail;
  94     }
  95
  96     if (!ssl_init_wbio_buffer(fixture.s, 1)) {
  97         fprintf(stderr, "Failed to set up wbio buffer for test: %s\n",
  98                 test_case_name);
  99         setup_ok = 0;
 100         goto fail;
 101     }
 102
 103     if (!ssl3_setup_buffers(fixture.s)) {
 104         fprintf(stderr, "Failed to setup buffers for test: %s\n",
 105                 test_case_name);
 106         setup_ok = 0;
 107         goto fail;
 108     }
 109
 110     /*
 111      * Clear the memory for the return buffer, since this isn't automatically
 112      * zeroed in opt mode and will cause spurious test failures that will
 113      * change with each execution.
 114      */
 115     memset(fixture.s->rlayer.wbuf.buf, 0, fixture.s->rlayer.wbuf.len);
 116
 117  fail:
 118     if (!setup_ok) {
 119         ERR_print_errors_fp(stderr);
 120         exit(EXIT_FAILURE);
 121     }
 122     return fixture;
 123 }
 124
 125 static HEARTBEAT_TEST_FIXTURE set_up_dtls(const char *const test_case_name)
 126 {
 127     HEARTBEAT_TEST_FIXTURE fixture = set_up(test_case_name,
 128                                             DTLSv1_server_method());
 129     fixture.process_heartbeat = dtls1_process_heartbeat;
 130
 131     /*
 132      * As per dtls1_get_record(), skipping the following from the beginning
 133      * of the returned heartbeat message: type-1 byte; version-2 bytes;
 134      * sequence number-8 bytes; length-2 bytes And then skipping the 1-byte
 135      * type encoded by process_heartbeat for a total of 14 bytes, at which
 136      * point we can grab the length and the payload we seek.
 137      */
 138     fixture.return_payload_offset = 14;
 139     return fixture;
 140 }
 141
 142 /* Needed by ssl3_write_bytes() */
 143 static int dummy_handshake(SSL *s)
 144 {
 145     return 1;
 146 }
 147
 148 static HEARTBEAT_TEST_FIXTURE set_up_tls(const char *const test_case_name)
 149 {
 150     HEARTBEAT_TEST_FIXTURE fixture = set_up(test_case_name,
 151                                             TLSv1_server_method());
 152     fixture.process_heartbeat = tls1_process_heartbeat;
 153     fixture.s->handshake_func = dummy_handshake;
 154
 155     /*
 156      * As per do_ssl3_write(), skipping the following from the beginning of
 157      * the returned heartbeat message: type-1 byte; version-2 bytes; length-2
 158      * bytes And then skipping the 1-byte type encoded by process_heartbeat
 159      * for a total of 6 bytes, at which point we can grab the length and the
 160      * payload we seek.
 161      */
 162     fixture.return_payload_offset = 6;
 163     return fixture;
 164 }
 165
 166 static void tear_down(HEARTBEAT_TEST_FIXTURE fixture)
 167 {
 168     ERR_print_errors_fp(stderr);
 169     SSL_free(fixture.s);
 170     SSL_CTX_free(fixture.ctx);
 171 }
 172
 173 static void print_payload(const char *const prefix,
 174                           const unsigned char *payload, const int n)
 175 {
 176     const int end = n < MAX_PRINTABLE_CHARACTERS ? n
 177         : MAX_PRINTABLE_CHARACTERS;
 178     int i = 0;
 179
 180     printf("%s %d character%s", prefix, n, n == 1 ? "" : "s");
 181     if (end != n)
 182         printf(" (first %d shown)", end);
 183     printf("\n  \"");
 184
 185     for (; i != end; ++i) {
 186         const unsigned char c = payload[i];
 187         if (isprint(c))
 188             fputc(c, stdout);
 189         else
 190             printf("\\x%02x", c);
 191     }
 192     printf("\"\n");
 193 }
 194
 195 static int execute_heartbeat(HEARTBEAT_TEST_FIXTURE fixture)
 196 {
 197     int result = 0;
 198     SSL *s = fixture.s;
 199     unsigned char *payload = fixture.payload;
 200     unsigned char sent_buf[MAX_PRINTABLE_CHARACTERS + 1];
 201     int return_value;
 202     unsigned const char *p;
 203     int actual_payload_len;
 204
 205     s->rlayer.rrec.data = payload;
 206     s->rlayer.rrec.length = strlen((const char *)payload);
 207     *payload++ = TLS1_HB_REQUEST;
 208     s2n(fixture.sent_payload_len, payload);
 209
 210     /*
 211      * Make a local copy of the request, since it gets overwritten at some
 212      * point
 213      */
 214     memcpy(sent_buf, payload, sizeof(sent_buf));
 215
 216     return_value = fixture.process_heartbeat(s, s->rlayer.rrec.data,
 217         s->rlayer.rrec.length);
 218
 219     if (return_value != fixture.expected_return_value) {
 220         printf("%s failed: expected return value %d, received %d\n",
 221                fixture.test_case_name, fixture.expected_return_value,
 222                return_value);
 223         result = 1;
 224     }
 225
 226     /*
 227      * If there is any byte alignment, it will be stored in wbuf.offset.
 228      */
 229     p = &(s->rlayer.
 230           wbuf.buf[fixture.return_payload_offset + s->rlayer.wbuf.offset]);
 231     actual_payload_len = 0;
 232     n2s(p, actual_payload_len);
 233
 234     if (actual_payload_len != fixture.expected_payload_len) {
 235         printf("%s failed:\n  expected payload len: %d\n  received: %d\n",
 236                fixture.test_case_name, fixture.expected_payload_len,
 237                actual_payload_len);
 238         print_payload("sent", sent_buf, strlen((const char *)sent_buf));
 239         print_payload("received", p, actual_payload_len);
 240         result = 1;
 241     } else {
 242         char *actual_payload =
 243             OPENSSL_strndup((const char *)p, actual_payload_len);
 244         if (strcmp(actual_payload, fixture.expected_return_payload) != 0) {
 245             printf
 246                 ("%s failed:\n  expected payload: \"%s\"\n  received: \"%s\"\n",
 247                  fixture.test_case_name, fixture.expected_return_payload,
 248                  actual_payload);
 249             result = 1;
 250         }
 251         OPENSSL_free(actual_payload);
 252     }
 253
 254     if (result != 0) {
 255         printf("** %s failed **\n--------\n", fixture.test_case_name);
 256     }
 257     return result;
 258 }
 259
 260 static int honest_payload_size(unsigned char payload_buf[])
 261 {
 262     /* Omit three-byte pad at the beginning for type and payload length */
 263     return strlen((const char *)&payload_buf[3]) - MIN_PADDING_SIZE;
 264 }
 265
 266 # define SETUP_HEARTBEAT_TEST_FIXTURE(type)\
 267   SETUP_TEST_FIXTURE(HEARTBEAT_TEST_FIXTURE, set_up_##type)
 268
 269 # define EXECUTE_HEARTBEAT_TEST()\
 270   EXECUTE_TEST(execute_heartbeat, tear_down)
 271
 272 static int test_dtls1_not_bleeding()
 273 {
 274     SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 275     /* Three-byte pad at the beginning for type and payload length */
 276     unsigned char payload_buf[MAX_PRINTABLE_CHARACTERS + 4] =
 277         "   Not bleeding, sixteen spaces of padding" "                ";
 278     const int payload_buf_len = honest_payload_size(payload_buf);
 279
 280     fixture.payload = &payload_buf[0];
 281     fixture.sent_payload_len = payload_buf_len;
 282     fixture.expected_return_value = 0;
 283     fixture.expected_payload_len = payload_buf_len;
 284     fixture.expected_return_payload =
 285         "Not bleeding, sixteen spaces of padding";
 286     EXECUTE_HEARTBEAT_TEST();
 287 }
 288
 289 static int test_dtls1_not_bleeding_empty_payload()
 290 {
 291     int payload_buf_len;
 292
 293     SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 294     /*
 295      * Three-byte pad at the beginning for type and payload length, plus a
 296      * NUL at the end
 297      */
 298     unsigned char payload_buf[4 + MAX_PRINTABLE_CHARACTERS];
 299     memset(payload_buf, ' ', MIN_PADDING_SIZE + 3);
 300     payload_buf[MIN_PADDING_SIZE + 3] = '\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[4 + MAX_PRINTABLE_CHARACTERS] =
 316         "   HEARTBLEED                ";
 317
 318     fixture.payload = &payload_buf[0];
 319     fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 320     fixture.expected_return_value = 0;
 321     fixture.expected_payload_len = 0;
 322     fixture.expected_return_payload = "";
 323     EXECUTE_HEARTBEAT_TEST();
 324 }
 325
 326 static int test_dtls1_heartbleed_empty_payload()
 327 {
 328     SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 329     /*
 330      * Excluding the NUL at the end, one byte short of type + payload length
 331      * + minimum padding
 332      */
 333     unsigned char payload_buf[MAX_PRINTABLE_CHARACTERS + 4];
 334     memset(payload_buf, ' ', MIN_PADDING_SIZE + 2);
 335     payload_buf[MIN_PADDING_SIZE + 2] = '\0';
 336
 337     fixture.payload = &payload_buf[0];
 338     fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 339     fixture.expected_return_value = 0;
 340     fixture.expected_payload_len = 0;
 341     fixture.expected_return_payload = "";
 342     EXECUTE_HEARTBEAT_TEST();
 343 }
 344
 345 static int test_dtls1_heartbleed_excessive_plaintext_length()
 346 {
 347     SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 348     /*
 349      * Excluding the NUL at the end, one byte in excess of maximum allowed
 350      * heartbeat message length
 351      */
 352     unsigned char payload_buf[SSL3_RT_MAX_PLAIN_LENGTH + 2];
 353     memset(payload_buf, ' ', sizeof(payload_buf));
 354     payload_buf[sizeof(payload_buf) - 1] = '\0';
 355
 356     fixture.payload = &payload_buf[0];
 357     fixture.sent_payload_len = honest_payload_size(payload_buf);
 358     fixture.expected_return_value = 0;
 359     fixture.expected_payload_len = 0;
 360     fixture.expected_return_payload = "";
 361     EXECUTE_HEARTBEAT_TEST();
 362 }
 363
 364 static int test_tls1_not_bleeding()
 365 {
 366     SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 367     /* Three-byte pad at the beginning for type and payload length */
 368     unsigned char payload_buf[MAX_PRINTABLE_CHARACTERS + 4] =
 369         "   Not bleeding, sixteen spaces of padding" "                ";
 370     const int payload_buf_len = honest_payload_size(payload_buf);
 371
 372     fixture.payload = &payload_buf[0];
 373     fixture.sent_payload_len = payload_buf_len;
 374     fixture.expected_return_value = 0;
 375     fixture.expected_payload_len = payload_buf_len;
 376     fixture.expected_return_payload =
 377         "Not bleeding, sixteen spaces of padding";
 378     EXECUTE_HEARTBEAT_TEST();
 379 }
 380
 381 static int test_tls1_not_bleeding_empty_payload()
 382 {
 383     int payload_buf_len;
 384
 385     SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 386     /*
 387      * Three-byte pad at the beginning for type and payload length, plus a
 388      * NUL at the end
 389      */
 390     unsigned char payload_buf[4 + MAX_PRINTABLE_CHARACTERS];
 391     memset(payload_buf, ' ', MIN_PADDING_SIZE + 3);
 392     payload_buf[MIN_PADDING_SIZE + 3] = '\0';
 393     payload_buf_len = honest_payload_size(payload_buf);
 394
 395     fixture.payload = &payload_buf[0];
 396     fixture.sent_payload_len = payload_buf_len;
 397     fixture.expected_return_value = 0;
 398     fixture.expected_payload_len = payload_buf_len;
 399     fixture.expected_return_payload = "";
 400     EXECUTE_HEARTBEAT_TEST();
 401 }
 402
 403 static int test_tls1_heartbleed()
 404 {
 405     SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 406     /* Three-byte pad at the beginning for type and payload length */
 407     unsigned char payload_buf[MAX_PRINTABLE_CHARACTERS + 4] =
 408         "   HEARTBLEED                ";
 409
 410     fixture.payload = &payload_buf[0];
 411     fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 412     fixture.expected_return_value = 0;
 413     fixture.expected_payload_len = 0;
 414     fixture.expected_return_payload = "";
 415     EXECUTE_HEARTBEAT_TEST();
 416 }
 417
 418 static int test_tls1_heartbleed_empty_payload()
 419 {
 420     SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 421     /*
 422      * Excluding the NUL at the end, one byte short of type + payload length
 423      * + minimum padding
 424      */
 425     unsigned char payload_buf[MAX_PRINTABLE_CHARACTERS + 4];
 426     memset(payload_buf, ' ', MIN_PADDING_SIZE + 2);
 427     payload_buf[MIN_PADDING_SIZE + 2] = '\0';
 428
 429     fixture.payload = &payload_buf[0];
 430     fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 431     fixture.expected_return_value = 0;
 432     fixture.expected_payload_len = 0;
 433     fixture.expected_return_payload = "";
 434     EXECUTE_HEARTBEAT_TEST();
 435 }
 436
 437 # undef EXECUTE_HEARTBEAT_TEST
 438 # undef SETUP_HEARTBEAT_TEST_FIXTURE
 439
 440 int main(int argc, char *argv[])
 441 {
 442     int result = 0;
 443
 444     SSL_library_init();
 445     SSL_load_error_strings();
 446
 447     ADD_TEST(test_dtls1_not_bleeding);
 448     ADD_TEST(test_dtls1_not_bleeding_empty_payload);
 449     ADD_TEST(test_dtls1_heartbleed);
 450     ADD_TEST(test_dtls1_heartbleed_empty_payload);
 451     ADD_TEST(test_dtls1_heartbleed_excessive_plaintext_length);
 452     ADD_TEST(test_tls1_not_bleeding);
 453     ADD_TEST(test_tls1_not_bleeding_empty_payload);
 454     ADD_TEST(test_tls1_heartbleed);
 455     ADD_TEST(test_tls1_heartbleed_empty_payload);
 456
 457     result = run_tests(argv[0]);
 458     ERR_print_errors_fp(stderr);
 459     return result;
 460 }
 461
 462 #else                           /* OPENSSL_NO_HEARTBEATS */
 463
 464 int main(int argc, char *argv[])
 465 {
 466     return EXIT_SUCCESS;
 467 }
 468 #endif                          /* OPENSSL_NO_HEARTBEATS */