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     SSL_CTX *ctx;
  61     SSL *s;
  62     const char *test_case_name;
  63     int (*process_heartbeat) (SSL *s);
  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->s3->wbuf.buf, 0, fixture.s->s3->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->s3->rrec.data = payload;
 206     s->s3->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((char *)sent_buf, (const char *)payload, sizeof(sent_buf));
 215
 216     return_value = fixture.process_heartbeat(s);
 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->s3->
 229           wbuf.buf[fixture.return_payload_offset + s->s3->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             BUF_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 */