heartbeat_test.c revision 279264
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 "../test/testutil.h"
44
45#include "../ssl/ssl_locl.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
59typedef struct heartbeat_test_fixture
60	{
61	SSL_CTX *ctx;
62	SSL *s;
63	const char* test_case_name;
64	int (*process_heartbeat)(SSL* s);
65	unsigned char* payload;
66	int sent_payload_len;
67	int expected_return_value;
68	int return_payload_offset;
69	int expected_payload_len;
70	const char* expected_return_payload;
71	} HEARTBEAT_TEST_FIXTURE;
72
73static HEARTBEAT_TEST_FIXTURE set_up(const char* const test_case_name,
74	const SSL_METHOD* meth)
75	{
76	HEARTBEAT_TEST_FIXTURE fixture;
77	int setup_ok = 1;
78	memset(&fixture, 0, sizeof(fixture));
79	fixture.test_case_name = test_case_name;
80
81	fixture.ctx = SSL_CTX_new(meth);
82	if (!fixture.ctx)
83		{
84		fprintf(stderr, "Failed to allocate SSL_CTX for test: %s\n",
85			test_case_name);
86		setup_ok = 0;
87		goto fail;
88		}
89
90	fixture.s = SSL_new(fixture.ctx);
91	if (!fixture.s)
92		{
93		fprintf(stderr, "Failed to allocate SSL for test: %s\n", test_case_name);
94		setup_ok = 0;
95		goto fail;
96		}
97
98	if (!ssl_init_wbio_buffer(fixture.s, 1))
99		{
100		fprintf(stderr, "Failed to set up wbio buffer for test: %s\n",
101			test_case_name);
102		setup_ok = 0;
103		goto fail;
104		}
105
106	if (!ssl3_setup_buffers(fixture.s))
107		{
108		fprintf(stderr, "Failed to setup buffers for test: %s\n",
109			test_case_name);
110		setup_ok = 0;
111		goto fail;
112		}
113
114	/* Clear the memory for the return buffer, since this isn't automatically
115	 * zeroed in opt mode and will cause spurious test failures that will change
116	 * with each execution.
117	 */
118	memset(fixture.s->s3->wbuf.buf, 0, fixture.s->s3->wbuf.len);
119
120	fail:
121	if (!setup_ok)
122		{
123		ERR_print_errors_fp(stderr);
124		exit(EXIT_FAILURE);
125		}
126	return fixture;
127	}
128
129static HEARTBEAT_TEST_FIXTURE set_up_dtls(const char* const test_case_name)
130	{
131	HEARTBEAT_TEST_FIXTURE fixture = set_up(test_case_name,
132		DTLSv1_server_method());
133	fixture.process_heartbeat = dtls1_process_heartbeat;
134
135	/* As per dtls1_get_record(), skipping the following from the beginning of
136	 * the returned heartbeat message:
137	 * type-1 byte; version-2 bytes; sequence number-8 bytes; length-2 bytes
138	 *
139	 * And then skipping the 1-byte type encoded by process_heartbeat for
140	 * a total of 14 bytes, at which point we can grab the length and the
141	 * payload we seek.
142	 */
143	fixture.return_payload_offset = 14;
144	return fixture;
145	}
146
147/* Needed by ssl3_write_bytes() */
148static int dummy_handshake(SSL* s)
149	{
150	return 1;
151	}
152
153static HEARTBEAT_TEST_FIXTURE set_up_tls(const char* const test_case_name)
154	{
155	HEARTBEAT_TEST_FIXTURE fixture = set_up(test_case_name,
156		TLSv1_server_method());
157	fixture.process_heartbeat = tls1_process_heartbeat;
158	fixture.s->handshake_func = dummy_handshake;
159
160	/* As per do_ssl3_write(), skipping the following from the beginning of
161	 * the returned heartbeat message:
162	 * type-1 byte; version-2 bytes; length-2 bytes
163	 *
164	 * And then skipping the 1-byte type encoded by process_heartbeat for
165	 * a total of 6 bytes, at which point we can grab the length and the payload
166	 * we seek.
167	 */
168	fixture.return_payload_offset = 6;
169	return fixture;
170	}
171
172static void tear_down(HEARTBEAT_TEST_FIXTURE fixture)
173	{
174	ERR_print_errors_fp(stderr);
175	SSL_free(fixture.s);
176	SSL_CTX_free(fixture.ctx);
177	}
178
179static void print_payload(const char* const prefix,
180		const unsigned char *payload, const int n)
181	{
182	const int end = n < MAX_PRINTABLE_CHARACTERS ? n
183	    : MAX_PRINTABLE_CHARACTERS;
184	int i = 0;
185
186	printf("%s %d character%s", prefix, n, n == 1 ? "" : "s");
187	if (end != n) printf(" (first %d shown)", end);
188	printf("\n  \"");
189
190	for (; i != end; ++i)
191		{
192		const unsigned char c = payload[i];
193		if (isprint(c)) fputc(c, stdout);
194		else printf("\\x%02x", c);
195		}
196	printf("\"\n");
197	}
198
199static int execute_heartbeat(HEARTBEAT_TEST_FIXTURE fixture)
200	{
201	int result = 0;
202	SSL* s = fixture.s;
203	unsigned char *payload = fixture.payload;
204	unsigned char sent_buf[MAX_PRINTABLE_CHARACTERS + 1];
205	int return_value;
206	unsigned const char *p;
207	int actual_payload_len;
208
209	s->s3->rrec.data = payload;
210	s->s3->rrec.length = strlen((const char*)payload);
211	*payload++ = TLS1_HB_REQUEST;
212	s2n(fixture.sent_payload_len, payload);
213
214	/* Make a local copy of the request, since it gets overwritten at some
215	 * point */
216	memcpy((char *)sent_buf, (const char*)payload, sizeof(sent_buf));
217
218	return_value = fixture.process_heartbeat(s);
219
220	if (return_value != fixture.expected_return_value)
221		{
222		printf("%s failed: expected return value %d, received %d\n",
223					 fixture.test_case_name, fixture.expected_return_value,
224					 return_value);
225		result = 1;
226		}
227
228	/* If there is any byte alignment, it will be stored in wbuf.offset. */
229	p = &(s->s3->wbuf.buf[
230			fixture.return_payload_offset + s->s3->wbuf.offset]);
231	actual_payload_len = 0;
232	n2s(p, actual_payload_len);
233
234	if (actual_payload_len != fixture.expected_payload_len)
235		{
236		printf("%s failed:\n  expected payload len: %d\n  received: %d\n",
237					 fixture.test_case_name, fixture.expected_payload_len,
238					 actual_payload_len);
239		print_payload("sent", sent_buf, strlen((const char*)sent_buf));
240		print_payload("received", p, actual_payload_len);
241		result = 1;
242		}
243	else
244		{
245		char* actual_payload = BUF_strndup((const char*)p, actual_payload_len);
246		if (strcmp(actual_payload, fixture.expected_return_payload) != 0)
247			{
248			printf("%s failed:\n  expected payload: \"%s\"\n  received: \"%s\"\n",
249						 fixture.test_case_name, fixture.expected_return_payload,
250						 actual_payload);
251			result = 1;
252			}
253		OPENSSL_free(actual_payload);
254		}
255
256	if (result != 0)
257		{
258		printf("** %s failed **\n--------\n", fixture.test_case_name);
259		}
260	return result;
261	}
262
263static int honest_payload_size(unsigned char payload_buf[])
264	{
265	/* Omit three-byte pad at the beginning for type and payload length */
266	return strlen((const char*)&payload_buf[3]) - MIN_PADDING_SIZE;
267	}
268
269#define SETUP_HEARTBEAT_TEST_FIXTURE(type)\
270  SETUP_TEST_FIXTURE(HEARTBEAT_TEST_FIXTURE, set_up_##type)
271
272#define EXECUTE_HEARTBEAT_TEST()\
273  EXECUTE_TEST(execute_heartbeat, tear_down)
274
275static int test_dtls1_not_bleeding()
276	{
277	SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
278	/* Three-byte pad at the beginning for type and payload length */
279	unsigned char payload_buf[] = "   Not bleeding, sixteen spaces of padding"
280		"                ";
281	const int payload_buf_len = honest_payload_size(payload_buf);
282
283	fixture.payload = &payload_buf[0];
284	fixture.sent_payload_len = payload_buf_len;
285	fixture.expected_return_value = 0;
286	fixture.expected_payload_len = payload_buf_len;
287	fixture.expected_return_payload = "Not bleeding, sixteen spaces of padding";
288	EXECUTE_HEARTBEAT_TEST();
289	}
290
291static int test_dtls1_not_bleeding_empty_payload()
292	{
293	int payload_buf_len;
294
295	SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
296	/* Three-byte pad at the beginning for type and payload length, plus a NUL
297	 * at the end */
298	unsigned char payload_buf[4 + MIN_PADDING_SIZE];
299	memset(payload_buf, ' ', sizeof(payload_buf));
300	payload_buf[sizeof(payload_buf) - 1] = '\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
311static 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[] = "   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
325static int test_dtls1_heartbleed_empty_payload()
326	{
327	SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
328	/* Excluding the NUL at the end, one byte short of type + payload length +
329	 * minimum padding */
330	unsigned char payload_buf[MIN_PADDING_SIZE + 3];
331	memset(payload_buf, ' ', sizeof(payload_buf));
332	payload_buf[sizeof(payload_buf) - 1] = '\0';
333
334	fixture.payload = &payload_buf[0];
335	fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
336	fixture.expected_return_value = 0;
337	fixture.expected_payload_len = 0;
338	fixture.expected_return_payload = "";
339	EXECUTE_HEARTBEAT_TEST();
340	}
341
342static int test_dtls1_heartbleed_excessive_plaintext_length()
343	{
344	SETUP_HEARTBEAT_TEST_FIXTURE(dtls);
345	/* Excluding the NUL at the end, one byte in excess of maximum allowed
346	 * heartbeat message length */
347	unsigned char payload_buf[SSL3_RT_MAX_PLAIN_LENGTH + 2];
348	memset(payload_buf, ' ', sizeof(payload_buf));
349	payload_buf[sizeof(payload_buf) - 1] = '\0';
350
351	fixture.payload = &payload_buf[0];
352	fixture.sent_payload_len = honest_payload_size(payload_buf);
353	fixture.expected_return_value = 0;
354	fixture.expected_payload_len = 0;
355	fixture.expected_return_payload = "";
356	EXECUTE_HEARTBEAT_TEST();
357	}
358
359static int test_tls1_not_bleeding()
360	{
361	SETUP_HEARTBEAT_TEST_FIXTURE(tls);
362	/* Three-byte pad at the beginning for type and payload length */
363	unsigned char payload_buf[] = "   Not bleeding, sixteen spaces of padding"
364					"                ";
365	const int payload_buf_len = honest_payload_size(payload_buf);
366
367	fixture.payload = &payload_buf[0];
368	fixture.sent_payload_len = payload_buf_len;
369	fixture.expected_return_value = 0;
370	fixture.expected_payload_len = payload_buf_len;
371	fixture.expected_return_payload = "Not bleeding, sixteen spaces of padding";
372	EXECUTE_HEARTBEAT_TEST();
373	}
374
375static int test_tls1_not_bleeding_empty_payload()
376	{
377	int payload_buf_len;
378
379	SETUP_HEARTBEAT_TEST_FIXTURE(tls);
380	/* Three-byte pad at the beginning for type and payload length, plus a NUL
381	 * at the end */
382	unsigned char payload_buf[4 + MIN_PADDING_SIZE];
383	memset(payload_buf, ' ', sizeof(payload_buf));
384	payload_buf[sizeof(payload_buf) - 1] = '\0';
385	payload_buf_len = honest_payload_size(payload_buf);
386
387	fixture.payload = &payload_buf[0];
388	fixture.sent_payload_len = payload_buf_len;
389	fixture.expected_return_value = 0;
390	fixture.expected_payload_len = payload_buf_len;
391	fixture.expected_return_payload = "";
392	EXECUTE_HEARTBEAT_TEST();
393	}
394
395static int test_tls1_heartbleed()
396	{
397	SETUP_HEARTBEAT_TEST_FIXTURE(tls);
398	/* Three-byte pad at the beginning for type and payload length */
399	unsigned char payload_buf[] = "   HEARTBLEED                ";
400
401	fixture.payload = &payload_buf[0];
402	fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
403	fixture.expected_return_value = 0;
404	fixture.expected_payload_len = 0;
405	fixture.expected_return_payload = "";
406	EXECUTE_HEARTBEAT_TEST();
407	}
408
409static int test_tls1_heartbleed_empty_payload()
410	{
411	SETUP_HEARTBEAT_TEST_FIXTURE(tls);
412	/* Excluding the NUL at the end, one byte short of type + payload length +
413	 * minimum padding */
414	unsigned char payload_buf[MIN_PADDING_SIZE + 3];
415	memset(payload_buf, ' ', sizeof(payload_buf));
416	payload_buf[sizeof(payload_buf) - 1] = '\0';
417
418	fixture.payload = &payload_buf[0];
419	fixture.sent_payload_len = MAX_PRINTABLE_CHARACTERS;
420	fixture.expected_return_value = 0;
421	fixture.expected_payload_len = 0;
422	fixture.expected_return_payload = "";
423	EXECUTE_HEARTBEAT_TEST();
424	}
425
426#undef EXECUTE_HEARTBEAT_TEST
427#undef SETUP_HEARTBEAT_TEST_FIXTURE
428
429int main(int argc, char *argv[])
430	{
431	int num_failed;
432
433	SSL_library_init();
434	SSL_load_error_strings();
435
436	num_failed = test_dtls1_not_bleeding() +
437	    test_dtls1_not_bleeding_empty_payload() +
438	    test_dtls1_heartbleed() +
439	    test_dtls1_heartbleed_empty_payload() +
440	    /* The following test causes an assertion failure at
441	     * ssl/d1_pkt.c:dtls1_write_bytes() in versions prior to 1.0.1g: */
442	    (OPENSSL_VERSION_NUMBER >= 0x1000107fL ?
443	     test_dtls1_heartbleed_excessive_plaintext_length() : 0) +
444	    test_tls1_not_bleeding() +
445	    test_tls1_not_bleeding_empty_payload() +
446	    test_tls1_heartbleed() +
447	    test_tls1_heartbleed_empty_payload() +
448	    0;
449
450	ERR_print_errors_fp(stderr);
451
452	if (num_failed != 0)
453		{
454		printf("%d test%s failed\n", num_failed, num_failed != 1 ? "s" : "");
455		return EXIT_FAILURE;
456		}
457	return EXIT_SUCCESS;
458	}
459
460#else /* OPENSSL_NO_HEARTBEATS*/
461
462int main(int argc, char *argv[])
463	{
464		return EXIT_SUCCESS;
465	}
466#endif /* OPENSSL_NO_HEARTBEATS */
467