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 #include "../ssl/ssl_locl.h"
  42 #include <ctype.h>
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46
  47 #if !defined(OPENSSL_NO_HEARTBEATS) && !defined(OPENSSL_SYS_WINDOWS)
  48
  49 /* As per https://tools.ietf.org/html/rfc6520#section-4 */
  50 #define MIN_PADDING_SIZE        16
  51
  52 /* Maximum number of payload characters to print as test output */
  53 #define MAX_PRINTABLE_CHARACTERS        1024
  54
  55 typedef struct heartbeat_test_fixture
  56         {
  57         SSL_CTX *ctx;
  58         SSL *s;
  59         const char* test_case_name;
  60         int (*process_heartbeat)(SSL* s);
  61         unsigned char* payload;
  62         int sent_payload_len;
  63         int expected_return_value;
  64         int return_payload_offset;
  65         int expected_payload_len;
  66         const char* expected_return_payload;
  67         } HEARTBEAT_TEST_FIXTURE;
  68
  69 static HEARTBEAT_TEST_FIXTURE set_up(const char* const test_case_name,
  70         const SSL_METHOD* meth)
  71         {
  72         HEARTBEAT_TEST_FIXTURE fixture;
  73         int setup_ok = 1;
  74         memset(&fixture, 0, sizeof(fixture));
  75         fixture.test_case_name = test_case_name;
  76
  77         fixture.ctx = SSL_CTX_new(meth);
  78         if (!fixture.ctx)
  79                 {
  80                 fprintf(stderr, "Failed to allocate SSL_CTX for test: %s\n",
  81                         test_case_name);
  82                 setup_ok = 0;
  83                 goto fail;
  84                 }
  85
  86         fixture.s = SSL_new(fixture.ctx);
  87         if (!fixture.s)
  88                 {
  89                 fprintf(stderr, "Failed to allocate SSL for test: %s\n", test_case_name);
  90                 setup_ok = 0;
  91                 goto fail;
  92                 }
  93
  94         if (!ssl_init_wbio_buffer(fixture.s, 1))
  95                 {
  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                 {
 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         /* 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 change
 112          * with each execution.
 113          */
 114         memset(fixture.s->s3->wbuf.buf, 0, fixture.s->s3->wbuf.len);
 115
 116         fail:
 117         if (!setup_ok)
 118                 {
 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         /* As per dtls1_get_record(), skipping the following from the beginning of
 132          * the returned heartbeat message:
 133          * type-1 byte; version-2 bytes; sequence number-8 bytes; length-2 bytes
 134          *
 135          * And then skipping the 1-byte type encoded by process_heartbeat for
 136          * a total of 14 bytes, at which point we can grab the length and the
 137          * payload we seek.
 138          */
 139         fixture.return_payload_offset = 14;
 140         return fixture;
 141         }
 142
 143 /* Needed by ssl3_write_bytes() */
 144 static int dummy_handshake(SSL* s)
 145         {
 146         return 1;
 147         }
 148
 149 static HEARTBEAT_TEST_FIXTURE set_up_tls(const char* const test_case_name)
 150         {
 151         HEARTBEAT_TEST_FIXTURE fixture = set_up(test_case_name,
 152                 TLSv1_server_method());
 153         fixture.process_heartbeat = tls1_process_heartbeat;
 154         fixture.s->handshake_func = dummy_handshake;
 155
 156         /* As per do_ssl3_write(), skipping the following from the beginning of
 157          * the returned heartbeat message:
 158          * type-1 byte; version-2 bytes; length-2 bytes
 159          *
 160          * And then skipping the 1-byte type encoded by process_heartbeat for
 161          * a total of 6 bytes, at which point we can grab the length and the payload
 162          * we seek.
 163          */
 164         fixture.return_payload_offset = 6;
 165         return fixture;
 166         }
 167
 168 static void tear_down(HEARTBEAT_TEST_FIXTURE fixture)
 169         {
 170         ERR_print_errors_fp(stderr);
 171         SSL_free(fixture.s);
 172         SSL_CTX_free(fixture.ctx);
 173         }
 174
 175 static void print_payload(const char* const prefix,
 176                 const unsigned char *payload, const int n)
 177         {
 178         const int end = n < MAX_PRINTABLE_CHARACTERS ? n
 179             : MAX_PRINTABLE_CHARACTERS;
 180         int i = 0;
 181
 182         printf("%s %d character%s", prefix, n, n == 1 ? "" : "s");
 183         if (end != n) printf(" (first %d shown)", end);
 184         printf("\n  \"");
 185
 186         for (; i != end; ++i)
 187                 {
 188                 const unsigned char c = payload[i];
 189                 if (isprint(c)) fputc(c, stdout);
 190                 else 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         /* Make a local copy of the request, since it gets overwritten at some
 211          * point */
 212         memcpy((char *)sent_buf, (const char*)payload, sizeof(sent_buf));
 213
 214         return_value = fixture.process_heartbeat(s);
 215
 216         if (return_value != fixture.expected_return_value)
 217                 {
 218                 printf("%s failed: expected return value %d, received %d\n",
 219                                          fixture.test_case_name, fixture.expected_return_value,
 220                                          return_value);
 221                 result = 1;
 222                 }
 223
 224         /* If there is any byte alignment, it will be stored in wbuf.offset. */
 225         p = &(s->s3->wbuf.buf[
 226                         fixture.return_payload_offset + s->s3->wbuf.offset]);
 227         actual_payload_len = 0;
 228         n2s(p, actual_payload_len);
 229
 230         if (actual_payload_len != fixture.expected_payload_len)
 231                 {
 232                 printf("%s failed:\n  expected payload len: %d\n  received: %d\n",
 233                                          fixture.test_case_name, fixture.expected_payload_len,
 234                                          actual_payload_len);
 235                 print_payload("sent", sent_buf, strlen((const char*)sent_buf));
 236                 print_payload("received", p, actual_payload_len);
 237                 result = 1;
 238                 }
 239         else
 240                 {
 241                 char* actual_payload = BUF_strndup((const char*)p, actual_payload_len);
 242                 if (strcmp(actual_payload, fixture.expected_return_payload) != 0)
 243                         {
 244                         printf("%s failed:\n  expected payload: \"%s\"\n  received: \"%s\"\n",
 245                                                  fixture.test_case_name, fixture.expected_return_payload,
 246                                                  actual_payload);
 247                         result = 1;
 248                         }
 249                 OPENSSL_free(actual_payload);
 250                 }
 251
 252         if (result != 0)
 253                 {
 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         HEARTBEAT_TEST_FIXTURE fixture = set_up_##type(__func__);\
 267         int result = 0
 268
 269 #define EXECUTE_HEARTBEAT_TEST()\
 270         if (execute_heartbeat(fixture) != 0) result = 1;\
 271         tear_down(fixture);\
 272         return result
 273
 274 static int test_dtls1_not_bleeding()
 275         {
 276         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 277         /* Three-byte pad at the beginning for type and payload length */
 278         unsigned char payload_buf[] = "   Not bleeding, sixteen spaces of padding"
 279                 "                ";
 280         const int payload_buf_len = honest_payload_size(payload_buf);
 281
 282         fixture.payload = &payload_buf[0];
 283         fixture.sent_payload_len = payload_buf_len;
 284         fixture.expected_return_value = 0;
 285         fixture.expected_payload_len = payload_buf_len;
 286         fixture.expected_return_payload = "Not bleeding, sixteen spaces of padding";
 287         EXECUTE_HEARTBEAT_TEST();
 288         }
 289
 290 static int test_dtls1_not_bleeding_empty_payload()
 291         {
 292         int payload_buf_len;
 293
 294         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 295         /* Three-byte pad at the beginning for type and payload length, plus a NUL
 296          * at the end */
 297         unsigned char payload_buf[4 + MIN_PADDING_SIZE];
 298         memset(payload_buf, ' ', sizeof(payload_buf));
 299         payload_buf[sizeof(payload_buf) - 1] = '\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[] = "   HEARTBLEED                ";
 315
 316         fixture.payload = &payload_buf[0];
 317         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 318         fixture.expected_return_value = 0;
 319         fixture.expected_payload_len = 0;
 320         fixture.expected_return_payload = "";
 321         EXECUTE_HEARTBEAT_TEST();
 322         }
 323
 324 static int test_dtls1_heartbleed_empty_payload()
 325         {
 326         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 327         /* Excluding the NUL at the end, one byte short of type + payload length +
 328          * minimum padding */
 329         unsigned char payload_buf[MIN_PADDING_SIZE + 3];
 330         memset(payload_buf, ' ', sizeof(payload_buf));
 331         payload_buf[sizeof(payload_buf) - 1] = '\0';
 332
 333         fixture.payload = &payload_buf[0];
 334         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 335         fixture.expected_return_value = 0;
 336         fixture.expected_payload_len = 0;
 337         fixture.expected_return_payload = "";
 338         EXECUTE_HEARTBEAT_TEST();
 339         }
 340
 341 static int test_dtls1_heartbleed_excessive_plaintext_length()
 342         {
 343         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 344         /* Excluding the NUL at the end, one byte in excess of maximum allowed
 345          * heartbeat message length */
 346         unsigned char payload_buf[SSL3_RT_MAX_PLAIN_LENGTH + 2];
 347         memset(payload_buf, ' ', sizeof(payload_buf));
 348         payload_buf[sizeof(payload_buf) - 1] = '\0';
 349
 350         fixture.payload = &payload_buf[0];
 351         fixture.sent_payload_len = honest_payload_size(payload_buf);
 352         fixture.expected_return_value = 0;
 353         fixture.expected_payload_len = 0;
 354         fixture.expected_return_payload = "";
 355         EXECUTE_HEARTBEAT_TEST();
 356         }
 357
 358 static int test_tls1_not_bleeding()
 359         {
 360         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 361         /* Three-byte pad at the beginning for type and payload length */
 362         unsigned char payload_buf[] = "   Not bleeding, sixteen spaces of padding"
 363                                         "                ";
 364         const int payload_buf_len = honest_payload_size(payload_buf);
 365
 366         fixture.payload = &payload_buf[0];
 367         fixture.sent_payload_len = payload_buf_len;
 368         fixture.expected_return_value = 0;
 369         fixture.expected_payload_len = payload_buf_len;
 370         fixture.expected_return_payload = "Not bleeding, sixteen spaces of padding";
 371         EXECUTE_HEARTBEAT_TEST();
 372         }
 373
 374 static int test_tls1_not_bleeding_empty_payload()
 375         {
 376         int payload_buf_len;
 377
 378         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 379         /* Three-byte pad at the beginning for type and payload length, plus a NUL
 380          * at the end */
 381         unsigned char payload_buf[4 + MIN_PADDING_SIZE];
 382         memset(payload_buf, ' ', sizeof(payload_buf));
 383         payload_buf[sizeof(payload_buf) - 1] = '\0';
 384         payload_buf_len = honest_payload_size(payload_buf);
 385
 386         fixture.payload = &payload_buf[0];
 387         fixture.sent_payload_len = payload_buf_len;
 388         fixture.expected_return_value = 0;
 389         fixture.expected_payload_len = payload_buf_len;
 390         fixture.expected_return_payload = "";
 391         EXECUTE_HEARTBEAT_TEST();
 392         }
 393
 394 static int test_tls1_heartbleed()
 395         {
 396         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 397         /* Three-byte pad at the beginning for type and payload length */
 398         unsigned char payload_buf[] = "   HEARTBLEED                ";
 399
 400         fixture.payload = &payload_buf[0];
 401         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 402         fixture.expected_return_value = 0;
 403         fixture.expected_payload_len = 0;
 404         fixture.expected_return_payload = "";
 405         EXECUTE_HEARTBEAT_TEST();
 406         }
 407
 408 static int test_tls1_heartbleed_empty_payload()
 409         {
 410         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 411         /* Excluding the NUL at the end, one byte short of type + payload length +
 412          * minimum padding */
 413         unsigned char payload_buf[MIN_PADDING_SIZE + 3];
 414         memset(payload_buf, ' ', sizeof(payload_buf));
 415         payload_buf[sizeof(payload_buf) - 1] = '\0';
 416
 417         fixture.payload = &payload_buf[0];
 418         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 419         fixture.expected_return_value = 0;
 420         fixture.expected_payload_len = 0;
 421         fixture.expected_return_payload = "";
 422         EXECUTE_HEARTBEAT_TEST();
 423         }
 424
 425 #undef EXECUTE_HEARTBEAT_TEST
 426 #undef SETUP_HEARTBEAT_TEST_FIXTURE
 427
 428 int main(int argc, char *argv[])
 429         {
 430         int num_failed;
 431
 432         SSL_library_init();
 433         SSL_load_error_strings();
 434
 435         num_failed = test_dtls1_not_bleeding() +
 436             test_dtls1_not_bleeding_empty_payload() +
 437             test_dtls1_heartbleed() +
 438             test_dtls1_heartbleed_empty_payload() +
 439             /* The following test causes an assertion failure at
 440              * ssl/d1_pkt.c:dtls1_write_bytes() in versions prior to 1.0.1g: */
 441             (OPENSSL_VERSION_NUMBER >= 0x1000107fL ?
 442              test_dtls1_heartbleed_excessive_plaintext_length() : 0) +
 443             test_tls1_not_bleeding() +
 444             test_tls1_not_bleeding_empty_payload() +
 445             test_tls1_heartbleed() +
 446             test_tls1_heartbleed_empty_payload() +
 447             0;
 448
 449         ERR_print_errors_fp(stderr);
 450
 451         if (num_failed != 0)
 452                 {
 453                 printf("%d test%s failed\n", num_failed, num_failed != 1 ? "s" : "");
 454                 return EXIT_FAILURE;
 455                 }
 456         return EXIT_SUCCESS;
 457         }
 458
 459 #else /* OPENSSL_NO_HEARTBEATS*/
 460
 461 int main(int argc, char *argv[])
 462         {
 463                 return EXIT_SUCCESS;
 464         }
 465 #endif /* OPENSSL_NO_HEARTBEATS */