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 /* As per https://tools.ietf.org/html/rfc6520#section-4 */
  48 #define MIN_PADDING_SIZE        16
  49
  50 /* Maximum number of payload characters to print as test output */
  51 #define MAX_PRINTABLE_CHARACTERS        1024
  52
  53 typedef struct heartbeat_test_fixture
  54         {
  55         SSL_CTX *ctx;
  56         SSL *s;
  57         const char* test_case_name;
  58         int (*process_heartbeat)(SSL* s);
  59         unsigned char* payload;
  60         int sent_payload_len;
  61         int expected_return_value;
  62         int return_payload_offset;
  63         int expected_payload_len;
  64         const char* expected_return_payload;
  65         } HEARTBEAT_TEST_FIXTURE;
  66
  67 static HEARTBEAT_TEST_FIXTURE set_up(const char* const test_case_name,
  68         const SSL_METHOD* meth)
  69         {
  70         HEARTBEAT_TEST_FIXTURE fixture;
  71         int setup_ok = 1;
  72         memset(&fixture, 0, sizeof(fixture));
  73         fixture.test_case_name = test_case_name;
  74
  75         fixture.ctx = SSL_CTX_new(meth);
  76         if (!fixture.ctx)
  77                 {
  78                 fprintf(stderr, "Failed to allocate SSL_CTX for test: %s\n",
  79                         test_case_name);
  80                 setup_ok = 0;
  81                 goto fail;
  82                 }
  83
  84         fixture.s = SSL_new(fixture.ctx);
  85         if (!fixture.s)
  86                 {
  87                 fprintf(stderr, "Failed to allocate SSL for test: %s\n", test_case_name);
  88                 setup_ok = 0;
  89                 goto fail;
  90                 }
  91
  92         if (!ssl_init_wbio_buffer(fixture.s, 1))
  93                 {
  94                 fprintf(stderr, "Failed to set up wbio buffer for test: %s\n",
  95                         test_case_name);
  96                 setup_ok = 0;
  97                 goto fail;
  98                 }
  99
 100         if (!ssl3_setup_buffers(fixture.s))
 101                 {
 102                 fprintf(stderr, "Failed to setup buffers for test: %s\n",
 103                         test_case_name);
 104                 setup_ok = 0;
 105                 goto fail;
 106                 }
 107
 108         /* Clear the memory for the return buffer, since this isn't automatically
 109          * zeroed in opt mode and will cause spurious test failures that will change
 110          * with each execution.
 111          */
 112         memset(fixture.s->s3->wbuf.buf, 0, fixture.s->s3->wbuf.len);
 113
 114         fail:
 115         if (!setup_ok)
 116                 {
 117                 ERR_print_errors_fp(stderr);
 118                 exit(EXIT_FAILURE);
 119                 }
 120         return fixture;
 121         }
 122
 123 static HEARTBEAT_TEST_FIXTURE set_up_dtls(const char* const test_case_name)
 124         {
 125         HEARTBEAT_TEST_FIXTURE fixture = set_up(test_case_name,
 126                 DTLSv1_server_method());
 127         fixture.process_heartbeat = dtls1_process_heartbeat;
 128
 129         /* As per dtls1_get_record(), skipping the following from the beginning of
 130          * the returned heartbeat message:
 131          * type-1 byte; version-2 bytes; sequence number-8 bytes; length-2 bytes
 132          *
 133          * And then skipping the 1-byte type encoded by process_heartbeat for
 134          * a total of 14 bytes, at which point we can grab the length and the
 135          * 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         /* As per do_ssl3_write(), skipping the following from the beginning of
 155          * the returned heartbeat message:
 156          * type-1 byte; version-2 bytes; length-2 bytes
 157          *
 158          * And then skipping the 1-byte type encoded by process_heartbeat for
 159          * a total of 6 bytes, at which point we can grab the length and the payload
 160          * 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) printf(" (first %d shown)", end);
 182         printf("\n  \"");
 183
 184         for (; i != end; ++i)
 185                 {
 186                 const unsigned char c = payload[i];
 187                 if (isprint(c)) fputc(c, stdout);
 188                 else printf("\\x%02x", c);
 189                 }
 190         printf("\"\n");
 191 }
 192
 193 static int execute_heartbeat(HEARTBEAT_TEST_FIXTURE fixture)
 194         {
 195         int result = 0;
 196         SSL* s = fixture.s;
 197         unsigned char *payload = fixture.payload;
 198         unsigned char sent_buf[MAX_PRINTABLE_CHARACTERS + 1];
 199         int return_value;
 200         unsigned const char *p;
 201         int actual_payload_len;
 202
 203         s->s3->rrec.data = payload;
 204         s->s3->rrec.length = strlen((const char*)payload);
 205         *payload++ = TLS1_HB_REQUEST;
 206         s2n(fixture.sent_payload_len, payload);
 207
 208         /* Make a local copy of the request, since it gets overwritten at some
 209          * point */
 210         memcpy((char *)sent_buf, (const char*)payload, sizeof(sent_buf));
 211
 212         return_value = fixture.process_heartbeat(s);
 213
 214         if (return_value != fixture.expected_return_value)
 215                 {
 216                 printf("%s failed: expected return value %d, received %d\n",
 217                                          fixture.test_case_name, fixture.expected_return_value,
 218                                          return_value);
 219                 result = 1;
 220                 }
 221
 222         /* If there is any byte alignment, it will be stored in wbuf.offset. */
 223         p = &(s->s3->wbuf.buf[
 224                         fixture.return_payload_offset + s->s3->wbuf.offset]);
 225         actual_payload_len = 0;
 226         n2s(p, actual_payload_len);
 227
 228         if (actual_payload_len != fixture.expected_payload_len)
 229                 {
 230                 printf("%s failed:\n  expected payload len: %d\n  received: %d\n",
 231                                          fixture.test_case_name, fixture.expected_payload_len,
 232                                          actual_payload_len);
 233                 print_payload("sent", sent_buf, strlen((const char*)sent_buf));
 234                 print_payload("received", p, actual_payload_len);
 235                 result = 1;
 236                 }
 237         else
 238                 {
 239                 char* actual_payload = strndup((const char*)p, actual_payload_len);
 240                 if (strcmp(actual_payload, fixture.expected_return_payload) != 0)
 241                         {
 242                         printf("%s failed:\n  expected payload: \"%s\"\n  received: \"%s\"\n",
 243                                                  fixture.test_case_name, fixture.expected_return_payload,
 244                                                  actual_payload);
 245                         result = 1;
 246                         }
 247                 free(actual_payload);
 248                 }
 249
 250         if (result != 0)
 251                 {
 252                 printf("** %s failed **\n--------\n", fixture.test_case_name);
 253                 }
 254         return result;
 255         }
 256
 257 static int honest_payload_size(unsigned char payload_buf[])
 258         {
 259         /* Omit three-byte pad at the beginning for type and payload length */
 260         return strlen((const char*)&payload_buf[3]) - MIN_PADDING_SIZE;
 261         }
 262
 263 #define SETUP_HEARTBEAT_TEST_FIXTURE(type)\
 264         HEARTBEAT_TEST_FIXTURE fixture = set_up_##type(__func__);\
 265         int result = 0
 266
 267 #define EXECUTE_HEARTBEAT_TEST()\
 268         if (execute_heartbeat(fixture) != 0) result = 1;\
 269         tear_down(fixture);\
 270         return result
 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[] = "   Not bleeding, sixteen spaces of padding"
 277                 "                ";
 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 = "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         /* Three-byte pad at the beginning for type and payload length, plus a NUL
 294          * at the end */
 295         unsigned char payload_buf[4 + MIN_PADDING_SIZE];
 296         memset(payload_buf, ' ', sizeof(payload_buf));
 297         payload_buf[sizeof(payload_buf) - 1] = '\0';
 298         payload_buf_len = honest_payload_size(payload_buf);
 299
 300         fixture.payload = &payload_buf[0];
 301         fixture.sent_payload_len = payload_buf_len;
 302         fixture.expected_return_value = 0;
 303         fixture.expected_payload_len = payload_buf_len;
 304         fixture.expected_return_payload = "";
 305         EXECUTE_HEARTBEAT_TEST();
 306         }
 307
 308 static int test_dtls1_heartbleed()
 309         {
 310         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 311         /* Three-byte pad at the beginning for type and payload length */
 312         unsigned char payload_buf[] = "   HEARTBLEED                ";
 313
 314         fixture.payload = &payload_buf[0];
 315         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 316         fixture.expected_return_value = 0;
 317         fixture.expected_payload_len = 0;
 318         fixture.expected_return_payload = "";
 319         EXECUTE_HEARTBEAT_TEST();
 320         }
 321
 322 static int test_dtls1_heartbleed_empty_payload()
 323         {
 324         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 325         /* Excluding the NUL at the end, one byte short of type + payload length +
 326          * minimum padding */
 327         unsigned char payload_buf[MIN_PADDING_SIZE + 3];
 328         memset(payload_buf, ' ', sizeof(payload_buf));
 329         payload_buf[sizeof(payload_buf) - 1] = '\0';
 330
 331         fixture.payload = &payload_buf[0];
 332         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 333         fixture.expected_return_value = 0;
 334         fixture.expected_payload_len = 0;
 335         fixture.expected_return_payload = "";
 336         EXECUTE_HEARTBEAT_TEST();
 337         }
 338
 339 static int test_dtls1_heartbleed_excessive_plaintext_length()
 340         {
 341         SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
 342         /* Excluding the NUL at the end, one byte in excess of maximum allowed
 343          * heartbeat message length */
 344         unsigned char payload_buf[SSL3_RT_MAX_PLAIN_LENGTH + 2];
 345         memset(payload_buf, ' ', sizeof(payload_buf));
 346         payload_buf[sizeof(payload_buf) - 1] = '\0';
 347
 348         fixture.payload = &payload_buf[0];
 349         fixture.sent_payload_len = honest_payload_size(payload_buf);
 350         fixture.expected_return_value = 0;
 351         fixture.expected_payload_len = 0;
 352         fixture.expected_return_payload = "";
 353         EXECUTE_HEARTBEAT_TEST();
 354         }
 355
 356 static int test_tls1_not_bleeding()
 357         {
 358         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 359         /* Three-byte pad at the beginning for type and payload length */
 360         unsigned char payload_buf[] = "   Not bleeding, sixteen spaces of padding"
 361                                         "                ";
 362         const int payload_buf_len = honest_payload_size(payload_buf);
 363
 364         fixture.payload = &payload_buf[0];
 365         fixture.sent_payload_len = payload_buf_len;
 366         fixture.expected_return_value = 0;
 367         fixture.expected_payload_len = payload_buf_len;
 368         fixture.expected_return_payload = "Not bleeding, sixteen spaces of padding";
 369         EXECUTE_HEARTBEAT_TEST();
 370         }
 371
 372 static int test_tls1_not_bleeding_empty_payload()
 373         {
 374         int payload_buf_len;
 375
 376         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 377         /* Three-byte pad at the beginning for type and payload length, plus a NUL
 378          * at the end */
 379         unsigned char payload_buf[4 + MIN_PADDING_SIZE];
 380         memset(payload_buf, ' ', sizeof(payload_buf));
 381         payload_buf[sizeof(payload_buf) - 1] = '\0';
 382         payload_buf_len = honest_payload_size(payload_buf);
 383
 384         fixture.payload = &payload_buf[0];
 385         fixture.sent_payload_len = payload_buf_len;
 386         fixture.expected_return_value = 0;
 387         fixture.expected_payload_len = payload_buf_len;
 388         fixture.expected_return_payload = "";
 389         EXECUTE_HEARTBEAT_TEST();
 390         }
 391
 392 static int test_tls1_heartbleed()
 393         {
 394         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 395         /* Three-byte pad at the beginning for type and payload length */
 396         unsigned char payload_buf[] = "   HEARTBLEED                ";
 397
 398         fixture.payload = &payload_buf[0];
 399         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 400         fixture.expected_return_value = 0;
 401         fixture.expected_payload_len = 0;
 402         fixture.expected_return_payload = "";
 403         EXECUTE_HEARTBEAT_TEST();
 404         }
 405
 406 static int test_tls1_heartbleed_empty_payload()
 407         {
 408         SETUP_HEARTBEAT_TEST_FIXTURE(tls);
 409         /* Excluding the NUL at the end, one byte short of type + payload length +
 410          * minimum padding */
 411         unsigned char payload_buf[MIN_PADDING_SIZE + 3];
 412         memset(payload_buf, ' ', sizeof(payload_buf));
 413         payload_buf[sizeof(payload_buf) - 1] = '\0';
 414
 415         fixture.payload = &payload_buf[0];
 416         fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
 417         fixture.expected_return_value = 0;
 418         fixture.expected_payload_len = 0;
 419         fixture.expected_return_payload = "";
 420         EXECUTE_HEARTBEAT_TEST();
 421         }
 422
 423 #undef EXECUTE_HEARTBEAT_TEST
 424 #undef SETUP_HEARTBEAT_TEST_FIXTURE
 425
 426 int main(int argc, char *argv[])
 427         {
 428         int num_failed;
 429
 430         SSL_library_init();
 431         SSL_load_error_strings();
 432
 433         num_failed = test_dtls1_not_bleeding() +
 434             test_dtls1_not_bleeding_empty_payload() +
 435             test_dtls1_heartbleed() +
 436             test_dtls1_heartbleed_empty_payload() +
 437             /* The following test causes an assertion failure at
 438              * ssl/d1_pkt.c:dtls1_write_bytes() in versions prior to 1.0.1g: */
 439             (OPENSSL_VERSION_NUMBER >= 0x1000107fL ?
 440              test_dtls1_heartbleed_excessive_plaintext_length() : 0) +
 441             test_tls1_not_bleeding() +
 442             test_tls1_not_bleeding_empty_payload() +
 443             test_tls1_heartbleed() +
 444             test_tls1_heartbleed_empty_payload() +
 445             0;
 446
 447         ERR_print_errors_fp(stderr);
 448
 449         if (num_failed != 0)
 450                 {
 451                 printf("%d test%s failed\n", num_failed, num_failed != 1 ? "s" : "");
 452                 return EXIT_FAILURE;
 453                 }
 454         return EXIT_SUCCESS;
 455         }