1 /*
2 * Mbed TLS SSL context deserializer from base64 code
3 *
4 * Copyright The Mbed TLS Contributors
5 * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6 */
7
8 #define MBEDTLS_DECLARE_PRIVATE_IDENTIFIERS
9
10 #include "mbedtls/build_info.h"
11 #include "mbedtls/debug.h"
12 #include "mbedtls/platform.h"
13
14 #include <stdio.h>
15 #include <stdlib.h>
16
17 #if !defined(MBEDTLS_X509_CRT_PARSE_C) || !defined(MBEDTLS_ERROR_C) || \
18 !defined(MBEDTLS_SSL_TLS_C)
main(void)19 int main(void)
20 {
21 printf("MBEDTLS_X509_CRT_PARSE_C and/or MBEDTLS_ERROR_C and/or "
22 "MBEDTLS_SSL_TLS_C not defined.\n");
23 return 0;
24 }
25 #else
26
27 #if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_DEPRECATE)
28 #define _CRT_SECURE_NO_DEPRECATE 1
29 #endif
30
31 #include <stdint.h>
32 #include <stdarg.h>
33 #include <string.h>
34 #if defined(MBEDTLS_HAVE_TIME)
35 #include <time.h>
36 #endif
37 #include "mbedtls/ssl.h"
38 #include "mbedtls/error.h"
39 #include "mbedtls/base64.h"
40 #include "mbedtls/md.h"
41 #include "mbedtls/x509_crt.h"
42 #include "mbedtls/ssl_ciphersuites.h"
43
44 /*
45 * This program version
46 */
47 #define PROG_NAME "ssl_context_info"
48 #define VER_MAJOR 0
49 #define VER_MINOR 1
50
51 /*
52 * Flags copied from the Mbed TLS library.
53 */
54 #define SESSION_CONFIG_TIME_BIT (1 << 0)
55 #define SESSION_CONFIG_CRT_BIT (1 << 1)
56 #define SESSION_CONFIG_CLIENT_TICKET_BIT (1 << 2)
57 #define SESSION_CONFIG_MFL_BIT (1 << 3)
58 #define SESSION_CONFIG_TRUNC_HMAC_BIT (1 << 4)
59 #define SESSION_CONFIG_ETM_BIT (1 << 5)
60 #define SESSION_CONFIG_TICKET_BIT (1 << 6)
61
62 #define CONTEXT_CONFIG_DTLS_CONNECTION_ID_BIT (1 << 0)
63 #define CONTEXT_CONFIG_DTLS_BADMAC_LIMIT_BIT (1 << 1)
64 #define CONTEXT_CONFIG_DTLS_ANTI_REPLAY_BIT (1 << 2)
65 #define CONTEXT_CONFIG_ALPN_BIT (1 << 3)
66
67 #define TRANSFORM_RANDBYTE_LEN 64
68
69 /*
70 * Minimum and maximum number of bytes for specific data: context, sessions,
71 * certificates, tickets and buffers in the program. The context and session
72 * size values have been calculated based on the 'print_deserialized_ssl_context()'
73 * and 'print_deserialized_ssl_session()' content.
74 */
75 #define MIN_CONTEXT_LEN 84
76 #define MIN_SESSION_LEN 88
77
78 #define MAX_CONTEXT_LEN 875 /* without session data */
79 #define MAX_SESSION_LEN 109 /* without certificate and ticket data */
80 #define MAX_CERTIFICATE_LEN ((1 << 24) - 1)
81 #define MAX_TICKET_LEN ((1 << 24) - 1)
82
83 #define MIN_SERIALIZED_DATA (MIN_CONTEXT_LEN + MIN_SESSION_LEN)
84 #define MAX_SERIALIZED_DATA (MAX_CONTEXT_LEN + MAX_SESSION_LEN + \
85 MAX_CERTIFICATE_LEN + MAX_TICKET_LEN)
86
87 #define MIN_BASE64_LEN (MIN_SERIALIZED_DATA * 4 / 3)
88 #define MAX_BASE64_LEN (MAX_SERIALIZED_DATA * 4 / 3 + 3)
89
90 /*
91 * A macro that prevents from reading out of the ssl buffer range.
92 */
93 #define CHECK_SSL_END(LEN) \
94 do \
95 { \
96 if (end - ssl < (int) (LEN)) \
97 { \
98 printf_err("%s", buf_ln_err); \
99 return; \
100 } \
101 } while (0)
102
103 /*
104 * Global values
105 */
106 FILE *b64_file = NULL; /* file with base64 codes to deserialize */
107 char conf_keep_peer_certificate = 1; /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE from mbedTLS configuration */
108 char conf_dtls_proto = 1; /* MBEDTLS_SSL_PROTO_DTLS from mbedTLS configuration */
109 char debug = 0; /* flag for debug messages */
110 const char alloc_err[] = "Cannot allocate memory\n";
111 const char buf_ln_err[] = "Buffer does not have enough data to complete the parsing\n";
112
113 /*
114 * Basic printing functions
115 */
print_version(void)116 static void print_version(void)
117 {
118 printf("%s v%d.%d\n", PROG_NAME, VER_MAJOR, VER_MINOR);
119 }
120
print_usage(void)121 static void print_usage(void)
122 {
123 print_version();
124 printf("\nThis program is used to deserialize an Mbed TLS SSL session from the base64 code provided\n"
125 "in the text file. The program can deserialize many codes from one file, but they must be\n"
126 "separated, e.g. by a newline.\n\n");
127 printf(
128 "Usage:\n"
129 "\t-f path - Path to the file with base64 code\n"
130 "\t-v - Show version\n"
131 "\t-h - Show this usage\n"
132 "\t-d - Print more information\n"
133 "\t--keep-peer-cert=0 - Use this option if you know that the Mbed TLS library\n"
134 "\t has been compiled with the MBEDTLS_SSL_KEEP_PEER_CERTIFICATE\n"
135 "\t flag. You can also use it if there are some problems with reading\n"
136 "\t the information about certificate\n"
137 "\t--dtls-protocol=0 - Use this option if you know that the Mbed TLS library\n"
138 "\t has been compiled without the MBEDTLS_SSL_PROTO_DTLS flag\n"
139 "\n"
140 );
141 }
142
printf_dbg(const char * str,...)143 static void printf_dbg(const char *str, ...)
144 {
145 if (debug) {
146 va_list args;
147 va_start(args, str);
148 printf("debug: ");
149 vprintf(str, args);
150 fflush(stdout);
151 va_end(args);
152 }
153 }
154
155 MBEDTLS_PRINTF_ATTRIBUTE(1, 2)
printf_err(const char * str,...)156 static void printf_err(const char *str, ...)
157 {
158 va_list args;
159 va_start(args, str);
160 fflush(stdout);
161 fprintf(stderr, "ERROR: ");
162 vfprintf(stderr, str, args);
163 fflush(stderr);
164 va_end(args);
165 }
166
167 /*
168 * Exit from the program in case of error
169 */
error_exit(void)170 static void error_exit(void)
171 {
172 if (NULL != b64_file) {
173 fclose(b64_file);
174 }
175 exit(-1);
176 }
177
178 /*
179 * This function takes the input arguments of this program
180 */
parse_arguments(int argc,char * argv[])181 static void parse_arguments(int argc, char *argv[])
182 {
183 int i = 1;
184
185 if (argc < 2) {
186 print_usage();
187 error_exit();
188 }
189
190 while (i < argc) {
191 if (strcmp(argv[i], "-d") == 0) {
192 debug = 1;
193 } else if (strcmp(argv[i], "-h") == 0) {
194 print_usage();
195 } else if (strcmp(argv[i], "-v") == 0) {
196 print_version();
197 } else if (strcmp(argv[i], "-f") == 0) {
198 if (++i >= argc) {
199 printf_err("File path is empty\n");
200 error_exit();
201 }
202
203 if (NULL != b64_file) {
204 printf_err("Cannot specify more than one file with -f\n");
205 error_exit();
206 }
207
208 if ((b64_file = fopen(argv[i], "r")) == NULL) {
209 printf_err("Cannot find file \"%s\"\n", argv[i]);
210 error_exit();
211 }
212 } else if (strcmp(argv[i], "--keep-peer-cert=0") == 0) {
213 conf_keep_peer_certificate = 0;
214 } else if (strcmp(argv[i], "--dtls-protocol=0") == 0) {
215 conf_dtls_proto = 0;
216 } else {
217 print_usage();
218 error_exit();
219 }
220
221 i++;
222 }
223 }
224
225 /*
226 * This function prints base64 code to the stdout
227 */
print_b64(const uint8_t * b,size_t len)228 static void print_b64(const uint8_t *b, size_t len)
229 {
230 size_t i = 0;
231 const uint8_t *end = b + len;
232 printf("\t");
233 while (b < end) {
234 if (++i > 75) {
235 printf("\n\t");
236 i = 0;
237 }
238 printf("%c", *b++);
239 }
240 printf("\n");
241 fflush(stdout);
242 }
243
244 /*
245 * This function prints hex code from the buffer to the stdout.
246 *
247 * /p b buffer with data to print
248 * /p len number of bytes to print
249 * /p in_line number of bytes in one line
250 * /p prefix prefix for the new lines
251 */
print_hex(const uint8_t * b,size_t len,const size_t in_line,const char * prefix)252 static void print_hex(const uint8_t *b, size_t len,
253 const size_t in_line, const char *prefix)
254 {
255 size_t i = 0;
256 const uint8_t *end = b + len;
257
258 if (prefix == NULL) {
259 prefix = "";
260 }
261
262 while (b < end) {
263 if (++i > in_line) {
264 printf("\n%s", prefix);
265 i = 1;
266 }
267 printf("%02X ", (uint8_t) *b++);
268 }
269 printf("\n");
270 fflush(stdout);
271 }
272
273 /*
274 * Print the value of time_t in format e.g. 2020-01-23 13:05:59
275 */
print_time(const uint64_t * time)276 static void print_time(const uint64_t *time)
277 {
278 #if defined(MBEDTLS_HAVE_TIME)
279 char buf[20];
280 struct tm *t = gmtime((time_t *) time);
281 static const char format[] = "%Y-%m-%d %H:%M:%S";
282 if (NULL != t) {
283 strftime(buf, sizeof(buf), format, t);
284 printf("%s\n", buf);
285 } else {
286 printf("unknown\n");
287 }
288 #else
289 (void) time;
290 printf("not supported\n");
291 #endif
292 }
293
294 /*
295 * Print the input string if the bit is set in the value
296 */
print_if_bit(const char * str,int bit,int val)297 static void print_if_bit(const char *str, int bit, int val)
298 {
299 if (bit & val) {
300 printf("\t%s\n", str);
301 }
302 }
303
304 /*
305 * Return pointer to hardcoded "enabled" or "disabled" depending on the input value
306 */
get_enabled_str(int is_en)307 static const char *get_enabled_str(int is_en)
308 {
309 return (is_en) ? "enabled" : "disabled";
310 }
311
312 /*
313 * Return pointer to hardcoded MFL string value depending on the MFL code at the input
314 */
get_mfl_str(int mfl_code)315 static const char *get_mfl_str(int mfl_code)
316 {
317 switch (mfl_code) {
318 case MBEDTLS_SSL_MAX_FRAG_LEN_NONE:
319 return "none";
320 case MBEDTLS_SSL_MAX_FRAG_LEN_512:
321 return "512";
322 case MBEDTLS_SSL_MAX_FRAG_LEN_1024:
323 return "1024";
324 case MBEDTLS_SSL_MAX_FRAG_LEN_2048:
325 return "2048";
326 case MBEDTLS_SSL_MAX_FRAG_LEN_4096:
327 return "4096";
328 default:
329 return "error";
330 }
331 }
332
333 /*
334 * Read next base64 code from the 'b64_file'. The 'b64_file' must be opened
335 * previously. After each call to this function, the internal file position
336 * indicator of the global b64_file is advanced.
337 *
338 * Note - This function checks the size of the input buffer and if necessary,
339 * increases it to the maximum MAX_BASE64_LEN
340 *
341 * /p b64 pointer to the pointer of the buffer for input data
342 * /p max_len pointer to the current buffer capacity. It can be changed if
343 * the buffer needs to be increased
344 *
345 * \retval number of bytes written in to the b64 buffer or 0 in case no more
346 * data was found
347 */
read_next_b64_code(uint8_t ** b64,size_t * max_len)348 static size_t read_next_b64_code(uint8_t **b64, size_t *max_len)
349 {
350 int valid_balance = 0; /* balance between valid and invalid characters */
351 size_t len = 0;
352 char pad = 0;
353 int c = 0;
354
355 while (EOF != c) {
356 char c_valid = 0;
357
358 c = fgetc(b64_file);
359
360 if (pad > 0) {
361 if (c == '=' && pad == 1) {
362 c_valid = 1;
363 pad = 2;
364 }
365 } else if ((c >= 'A' && c <= 'Z') ||
366 (c >= 'a' && c <= 'z') ||
367 (c >= '0' && c <= '9') ||
368 c == '+' || c == '/') {
369 c_valid = 1;
370 } else if (c == '=') {
371 c_valid = 1;
372 pad = 1;
373 } else if (c == '-') {
374 c = '+';
375 c_valid = 1;
376 } else if (c == '_') {
377 c = '/';
378 c_valid = 1;
379 }
380
381 if (c_valid) {
382 /* A string of characters that could be a base64 code. */
383 valid_balance++;
384
385 if (len < *max_len) {
386 (*b64)[len++] = c;
387 } else if (*max_len < MAX_BASE64_LEN) {
388 /* Current buffer is too small, but can be resized. */
389 void *ptr;
390 size_t new_size = (MAX_BASE64_LEN - 4096 > *max_len) ?
391 *max_len + 4096 : MAX_BASE64_LEN;
392
393 ptr = realloc(*b64, new_size);
394 if (NULL == ptr) {
395 printf_err(alloc_err);
396 return 0;
397 }
398 *b64 = ptr;
399 *max_len = new_size;
400 (*b64)[len++] = c;
401 } else {
402 /* Too much data so it will be treated as invalid */
403 len++;
404 }
405 } else if (len > 0) {
406 /* End of a string that could be a base64 code, but need to check
407 * that the length of the characters is correct. */
408
409 valid_balance--;
410
411 if (len < MIN_CONTEXT_LEN) {
412 printf_dbg("The code found is too small to be a SSL context.\n");
413 len = pad = 0;
414 } else if (len > *max_len) {
415 printf_err("The code found is too large by %" MBEDTLS_PRINTF_SIZET " bytes.\n",
416 len - *max_len);
417 len = pad = 0;
418 } else if (len % 4 != 0) {
419 printf_err("The length of the base64 code found should be a multiple of 4.\n");
420 len = pad = 0;
421 } else {
422 /* Base64 code with valid character length. */
423 return len;
424 }
425 } else {
426 valid_balance--;
427 }
428
429 /* Detection of potentially wrong file format like: binary, zip, ISO, etc. */
430 if (valid_balance < -100) {
431 printf_err("Too many bad symbols detected. File check aborted.\n");
432 return 0;
433 }
434 }
435
436 printf_dbg("End of file\n");
437 return 0;
438 }
439
440 #if !defined(MBEDTLS_X509_REMOVE_INFO)
441 /*
442 * This function deserializes and prints to the stdout all obtained information
443 * about the certificates from provided data.
444 *
445 * /p ssl pointer to serialized certificate
446 * /p len number of bytes in the buffer
447 */
print_deserialized_ssl_cert(const uint8_t * ssl,uint32_t len)448 static void print_deserialized_ssl_cert(const uint8_t *ssl, uint32_t len)
449 {
450 enum { STRLEN = 4096 };
451 mbedtls_x509_crt crt;
452 int ret;
453 char str[STRLEN];
454
455 printf("\nCertificate:\n");
456
457 mbedtls_x509_crt_init(&crt);
458 ret = mbedtls_x509_crt_parse_der(&crt, ssl, len);
459 if (0 != ret) {
460 mbedtls_strerror(ret, str, STRLEN);
461 printf_err("Invalid format of X.509 - %s\n", str);
462 printf("Cannot deserialize:\n\t");
463 print_hex(ssl, len, 25, "\t");
464 } else {
465 mbedtls_x509_crt *current = &crt;
466
467 while (current != NULL) {
468 ret = mbedtls_x509_crt_info(str, STRLEN, "\t", current);
469 if (0 > ret) {
470 mbedtls_strerror(ret, str, STRLEN);
471 printf_err("Cannot write to the output - %s\n", str);
472 } else {
473 printf("%s", str);
474 }
475
476 current = current->next;
477
478 if (current) {
479 printf("\n");
480 }
481
482 }
483 }
484
485 mbedtls_x509_crt_free(&crt);
486 }
487 #endif /* !MBEDTLS_X509_REMOVE_INFO */
488
489 /*
490 * This function deserializes and prints to the stdout all obtained information
491 * about the session from provided data. This function was built based on
492 * mbedtls_ssl_session_load(). mbedtls_ssl_session_load() could not be used
493 * due to dependencies on the mbedTLS configuration.
494 *
495 * The data structure in the buffer:
496 * uint64 start_time;
497 * uint8 ciphersuite[2]; // defined by the standard
498 * uint8 compression; // 0 or 1
499 * uint8 session_id_len; // at most 32
500 * opaque session_id[32];
501 * opaque master[48]; // fixed length in the standard
502 * uint32 verify_result;
503 * opaque peer_cert<0..2^24-1>; // length 0 means no peer cert
504 * opaque ticket<0..2^24-1>; // length 0 means no ticket
505 * uint32 ticket_lifetime;
506 * uint8 mfl_code; // up to 255 according to standard
507 * uint8 trunc_hmac; // 0 or 1
508 * uint8 encrypt_then_mac; // 0 or 1
509 *
510 * /p ssl pointer to serialized session
511 * /p len number of bytes in the buffer
512 * /p session_cfg_flag session configuration flags
513 */
print_deserialized_ssl_session(const uint8_t * ssl,uint32_t len,int session_cfg_flag)514 static void print_deserialized_ssl_session(const uint8_t *ssl, uint32_t len,
515 int session_cfg_flag)
516 {
517 const struct mbedtls_ssl_ciphersuite_t *ciphersuite_info;
518 int ciphersuite_id;
519 uint32_t cert_len, ticket_len;
520 uint32_t verify_result, ticket_lifetime;
521 const uint8_t *end = ssl + len;
522
523 printf("\nSession info:\n");
524
525 if (session_cfg_flag & SESSION_CONFIG_TIME_BIT) {
526 uint64_t start;
527 CHECK_SSL_END(8);
528 start = ((uint64_t) ssl[0] << 56) |
529 ((uint64_t) ssl[1] << 48) |
530 ((uint64_t) ssl[2] << 40) |
531 ((uint64_t) ssl[3] << 32) |
532 ((uint64_t) ssl[4] << 24) |
533 ((uint64_t) ssl[5] << 16) |
534 ((uint64_t) ssl[6] << 8) |
535 ((uint64_t) ssl[7]);
536 ssl += 8;
537 printf("\tstart time : ");
538 print_time(&start);
539 }
540
541 CHECK_SSL_END(2);
542 ciphersuite_id = ((int) ssl[0] << 8) | (int) ssl[1];
543 printf_dbg("Ciphersuite ID: %d\n", ciphersuite_id);
544 ssl += 2;
545
546 ciphersuite_info = mbedtls_ssl_ciphersuite_from_id(ciphersuite_id);
547 if (ciphersuite_info == NULL) {
548 printf_err("Cannot find ciphersuite info\n");
549 } else {
550 printf("\tciphersuite : %s\n", mbedtls_ssl_ciphersuite_get_name(ciphersuite_info));
551 printf("\tcipher flags : 0x%02X\n", ciphersuite_info->MBEDTLS_PRIVATE(flags));
552 printf("\tcipher type : %d\n", ciphersuite_info->MBEDTLS_PRIVATE(cipher));
553 printf("\tMessage-Digest : %d\n", ciphersuite_info->MBEDTLS_PRIVATE(mac));
554 }
555
556 CHECK_SSL_END(1);
557 printf("\tcompression : %s\n", get_enabled_str(*ssl++));
558
559 /* Note - Here we can get session ID length from serialized data, but we
560 * use hardcoded 32-bytes length. This approach was taken from
561 * 'mbedtls_ssl_session_load()'. */
562 CHECK_SSL_END(1 + 32);
563 printf_dbg("Session id length: %u\n", (uint32_t) *ssl++);
564 printf("\tsession ID : ");
565 print_hex(ssl, 32, 16, "\t ");
566 ssl += 32;
567
568 printf("\tmaster secret : ");
569 CHECK_SSL_END(48);
570 print_hex(ssl, 48, 16, "\t ");
571 ssl += 48;
572
573 CHECK_SSL_END(4);
574 verify_result = ((uint32_t) ssl[0] << 24) |
575 ((uint32_t) ssl[1] << 16) |
576 ((uint32_t) ssl[2] << 8) |
577 ((uint32_t) ssl[3]);
578 ssl += 4;
579 printf("\tverify result : 0x%08X\n", verify_result);
580
581 if (SESSION_CONFIG_CRT_BIT & session_cfg_flag) {
582 if (conf_keep_peer_certificate) {
583 CHECK_SSL_END(3);
584 cert_len = ((uint32_t) ssl[0] << 16) |
585 ((uint32_t) ssl[1] << 8) |
586 ((uint32_t) ssl[2]);
587 ssl += 3;
588 printf_dbg("Certificate length: %u\n", cert_len);
589
590 if (cert_len > 0) {
591 CHECK_SSL_END(cert_len);
592 #if !defined(MBEDTLS_X509_REMOVE_INFO)
593 print_deserialized_ssl_cert(ssl, cert_len);
594 #endif
595 ssl += cert_len;
596 }
597 } else {
598 printf("\tPeer digest : ");
599
600 CHECK_SSL_END(1);
601 switch ((mbedtls_md_type_t) *ssl++) {
602 case MBEDTLS_MD_NONE:
603 printf("none\n");
604 break;
605 case MBEDTLS_MD_MD5:
606 printf("MD5\n");
607 break;
608 case MBEDTLS_MD_SHA1:
609 printf("SHA1\n");
610 break;
611 case MBEDTLS_MD_SHA224:
612 printf("SHA224\n");
613 break;
614 case MBEDTLS_MD_SHA256:
615 printf("SHA256\n");
616 break;
617 case MBEDTLS_MD_SHA384:
618 printf("SHA384\n");
619 break;
620 case MBEDTLS_MD_SHA512:
621 printf("SHA512\n");
622 break;
623 case MBEDTLS_MD_RIPEMD160:
624 printf("RIPEMD160\n");
625 break;
626 default:
627 printf("undefined or erroneous\n");
628 break;
629 }
630
631 CHECK_SSL_END(1);
632 cert_len = (uint32_t) *ssl++;
633 printf_dbg("Message-Digest length: %u\n", cert_len);
634
635 if (cert_len > 0) {
636 printf("\tPeer digest cert : ");
637 CHECK_SSL_END(cert_len);
638 print_hex(ssl, cert_len, 16, "\t ");
639 ssl += cert_len;
640 }
641 }
642 }
643
644 if (SESSION_CONFIG_CLIENT_TICKET_BIT & session_cfg_flag) {
645 printf("\nTicket:\n");
646
647 CHECK_SSL_END(3);
648 ticket_len = ((uint32_t) ssl[0] << 16) |
649 ((uint32_t) ssl[1] << 8) |
650 ((uint32_t) ssl[2]);
651 ssl += 3;
652 printf_dbg("Ticket length: %u\n", ticket_len);
653
654 if (ticket_len > 0) {
655 printf("\t");
656 CHECK_SSL_END(ticket_len);
657 print_hex(ssl, ticket_len, 22, "\t");
658 ssl += ticket_len;
659 printf("\n");
660 }
661
662 CHECK_SSL_END(4);
663 ticket_lifetime = ((uint32_t) ssl[0] << 24) |
664 ((uint32_t) ssl[1] << 16) |
665 ((uint32_t) ssl[2] << 8) |
666 ((uint32_t) ssl[3]);
667 ssl += 4;
668 printf("\tlifetime : %u sec.\n", ticket_lifetime);
669 }
670
671 if (ssl < end) {
672 printf("\nSession others:\n");
673 }
674
675 if (SESSION_CONFIG_MFL_BIT & session_cfg_flag) {
676 CHECK_SSL_END(1);
677 printf("\tMFL : %s\n", get_mfl_str(*ssl++));
678 }
679
680 if (SESSION_CONFIG_TRUNC_HMAC_BIT & session_cfg_flag) {
681 CHECK_SSL_END(1);
682 printf("\tnegotiate truncated HMAC : %s\n", get_enabled_str(*ssl++));
683 }
684
685 if (SESSION_CONFIG_ETM_BIT & session_cfg_flag) {
686 CHECK_SSL_END(1);
687 printf("\tEncrypt-then-MAC : %s\n", get_enabled_str(*ssl++));
688 }
689
690 if (0 != (end - ssl)) {
691 printf_err("%i bytes left to analyze from session\n", (int32_t) (end - ssl));
692 }
693 }
694
695 /*
696 * This function deserializes and prints to the stdout all obtained information
697 * about the context from provided data. This function was built based on
698 * mbedtls_ssl_context_load(). mbedtls_ssl_context_load() could not be used
699 * due to dependencies on the mbedTLS configuration and the configuration of
700 * the context when serialization was created.
701 *
702 * The data structure in the buffer:
703 * // header
704 * uint8 version[3];
705 * uint8 configuration[5];
706 * // session sub-structure
707 * uint32_t session_len;
708 * opaque session<1..2^32-1>; // see mbedtls_ssl_session_save()
709 * // transform sub-structure
710 * uint8 random[64]; // ServerHello.random+ClientHello.random
711 * uint8 in_cid_len;
712 * uint8 in_cid<0..2^8-1> // Connection ID: expected incoming value
713 * uint8 out_cid_len;
714 * uint8 out_cid<0..2^8-1> // Connection ID: outgoing value to use
715 * // fields from ssl_context
716 * uint32 badmac_seen; // DTLS: number of records with failing MAC
717 * uint64 in_window_top; // DTLS: last validated record seq_num
718 * uint64 in_window; // DTLS: bitmask for replay protection
719 * uint8 disable_datagram_packing; // DTLS: only one record per datagram
720 * uint64 cur_out_ctr; // Record layer: outgoing sequence number
721 * uint16 mtu; // DTLS: path mtu (max outgoing fragment size)
722 * uint8 alpn_chosen_len;
723 * uint8 alpn_chosen<0..2^8-1> // ALPN: negotiated application protocol
724 *
725 * /p ssl pointer to serialized session
726 * /p len number of bytes in the buffer
727 */
print_deserialized_ssl_context(const uint8_t * ssl,size_t len)728 static void print_deserialized_ssl_context(const uint8_t *ssl, size_t len)
729 {
730 const uint8_t *end = ssl + len;
731 uint32_t session_len;
732 int session_cfg_flag;
733 int context_cfg_flag;
734
735 printf("\nMbed TLS version:\n");
736
737 CHECK_SSL_END(3 + 2 + 3);
738
739 printf("\tmajor %u\n", (uint32_t) *ssl++);
740 printf("\tminor %u\n", (uint32_t) *ssl++);
741 printf("\tpath %u\n", (uint32_t) *ssl++);
742
743 printf("\nEnabled session and context configuration:\n");
744
745 session_cfg_flag = ((int) ssl[0] << 8) | ((int) ssl[1]);
746 ssl += 2;
747
748 context_cfg_flag = ((int) ssl[0] << 16) |
749 ((int) ssl[1] << 8) |
750 ((int) ssl[2]);
751 ssl += 3;
752
753 printf_dbg("Session config flags 0x%04X\n", session_cfg_flag);
754 printf_dbg("Context config flags 0x%06X\n", context_cfg_flag);
755
756 print_if_bit("MBEDTLS_HAVE_TIME", SESSION_CONFIG_TIME_BIT, session_cfg_flag);
757 print_if_bit("MBEDTLS_X509_CRT_PARSE_C", SESSION_CONFIG_CRT_BIT, session_cfg_flag);
758 print_if_bit("MBEDTLS_SSL_MAX_FRAGMENT_LENGTH", SESSION_CONFIG_MFL_BIT, session_cfg_flag);
759 print_if_bit("MBEDTLS_SSL_ENCRYPT_THEN_MAC", SESSION_CONFIG_ETM_BIT, session_cfg_flag);
760 print_if_bit("MBEDTLS_SSL_SESSION_TICKETS", SESSION_CONFIG_TICKET_BIT, session_cfg_flag);
761 print_if_bit("MBEDTLS_SSL_SESSION_TICKETS and client",
762 SESSION_CONFIG_CLIENT_TICKET_BIT,
763 session_cfg_flag);
764
765 print_if_bit("MBEDTLS_SSL_DTLS_CONNECTION_ID",
766 CONTEXT_CONFIG_DTLS_CONNECTION_ID_BIT,
767 context_cfg_flag);
768 print_if_bit("MBEDTLS_SSL_DTLS_ANTI_REPLAY",
769 CONTEXT_CONFIG_DTLS_ANTI_REPLAY_BIT,
770 context_cfg_flag);
771 print_if_bit("MBEDTLS_SSL_ALPN", CONTEXT_CONFIG_ALPN_BIT, context_cfg_flag);
772
773 CHECK_SSL_END(4);
774 session_len = ((uint32_t) ssl[0] << 24) |
775 ((uint32_t) ssl[1] << 16) |
776 ((uint32_t) ssl[2] << 8) |
777 ((uint32_t) ssl[3]);
778 ssl += 4;
779 printf_dbg("Session length %u\n", session_len);
780
781 CHECK_SSL_END(session_len);
782 print_deserialized_ssl_session(ssl, session_len, session_cfg_flag);
783 ssl += session_len;
784
785 printf("\nRandom bytes:\n\t");
786
787 CHECK_SSL_END(TRANSFORM_RANDBYTE_LEN);
788 print_hex(ssl, TRANSFORM_RANDBYTE_LEN, 22, "\t");
789 ssl += TRANSFORM_RANDBYTE_LEN;
790
791 printf("\nContext others:\n");
792
793 if (CONTEXT_CONFIG_DTLS_CONNECTION_ID_BIT & context_cfg_flag) {
794 uint8_t cid_len;
795
796 CHECK_SSL_END(1);
797 cid_len = *ssl++;
798 printf_dbg("In CID length %u\n", (uint32_t) cid_len);
799
800 printf("\tin CID : ");
801 if (cid_len > 0) {
802 CHECK_SSL_END(cid_len);
803 print_hex(ssl, cid_len, 20, "\t");
804 ssl += cid_len;
805 } else {
806 printf("none\n");
807 }
808
809 CHECK_SSL_END(1);
810 cid_len = *ssl++;
811 printf_dbg("Out CID length %u\n", (uint32_t) cid_len);
812
813 printf("\tout CID : ");
814 if (cid_len > 0) {
815 CHECK_SSL_END(cid_len);
816 print_hex(ssl, cid_len, 20, "\t");
817 ssl += cid_len;
818 } else {
819 printf("none\n");
820 }
821 }
822
823 if (CONTEXT_CONFIG_DTLS_BADMAC_LIMIT_BIT & context_cfg_flag) {
824 uint32_t badmac_seen;
825
826 CHECK_SSL_END(4);
827 badmac_seen = ((uint32_t) ssl[0] << 24) |
828 ((uint32_t) ssl[1] << 16) |
829 ((uint32_t) ssl[2] << 8) |
830 ((uint32_t) ssl[3]);
831 ssl += 4;
832 printf("\tbad MAC seen number : %u\n", badmac_seen);
833
834 /* value 'in_window_top' from mbedtls_ssl_context */
835 printf("\tlast validated record sequence no. : ");
836 CHECK_SSL_END(8);
837 print_hex(ssl, 8, 20, "");
838 ssl += 8;
839
840 /* value 'in_window' from mbedtls_ssl_context */
841 printf("\tbitmask for replay detection : ");
842 CHECK_SSL_END(8);
843 print_hex(ssl, 8, 20, "");
844 ssl += 8;
845 }
846
847 if (conf_dtls_proto) {
848 CHECK_SSL_END(1);
849 printf("\tDTLS datagram packing : %s\n",
850 get_enabled_str(!(*ssl++)));
851 }
852
853 /* value 'cur_out_ctr' from mbedtls_ssl_context */
854 printf("\toutgoing record sequence no. : ");
855 CHECK_SSL_END(8);
856 print_hex(ssl, 8, 20, "");
857 ssl += 8;
858
859 if (conf_dtls_proto) {
860 uint16_t mtu;
861 CHECK_SSL_END(2);
862 mtu = (ssl[0] << 8) | ssl[1];
863 ssl += 2;
864 printf("\tMTU : %u\n", mtu);
865 }
866
867
868 if (CONTEXT_CONFIG_ALPN_BIT & context_cfg_flag) {
869 uint8_t alpn_len;
870
871 CHECK_SSL_END(1);
872 alpn_len = *ssl++;
873 printf_dbg("ALPN length %u\n", (uint32_t) alpn_len);
874
875 printf("\tALPN negotiation : ");
876 CHECK_SSL_END(alpn_len);
877 if (alpn_len > 0) {
878 if (strlen((const char *) ssl) == alpn_len) {
879 printf("%s\n", ssl);
880 } else {
881 printf("\n");
882 printf_err("\tALPN negotiation is incorrect\n");
883 }
884 ssl += alpn_len;
885 } else {
886 printf("not selected\n");
887 }
888 }
889
890 if (0 != (end - ssl)) {
891 printf_err("%i bytes left to analyze from context\n", (int32_t) (end - ssl));
892 }
893 printf("\n");
894 }
895
main(int argc,char * argv[])896 int main(int argc, char *argv[])
897 {
898 enum { SSL_INIT_LEN = 4096 };
899
900 uint32_t b64_counter = 0;
901 uint8_t *b64_buf = NULL;
902 uint8_t *ssl_buf = NULL;
903 size_t b64_max_len = SSL_INIT_LEN;
904 size_t ssl_max_len = SSL_INIT_LEN;
905 size_t ssl_len = 0;
906
907 psa_status_t status = psa_crypto_init();
908 if (status != PSA_SUCCESS) {
909 mbedtls_fprintf(stderr, "Failed to initialize PSA Crypto implementation: %d\n",
910 (int) status);
911 return MBEDTLS_ERR_SSL_HW_ACCEL_FAILED;
912 }
913
914 /* The 'b64_file' is opened when parsing arguments to check that the
915 * file name is correct */
916 parse_arguments(argc, argv);
917
918 if (NULL != b64_file) {
919 b64_buf = malloc(SSL_INIT_LEN);
920 ssl_buf = malloc(SSL_INIT_LEN);
921
922 if (NULL == b64_buf || NULL == ssl_buf) {
923 printf_err(alloc_err);
924 fclose(b64_file);
925 b64_file = NULL;
926 }
927 }
928
929 while (NULL != b64_file) {
930 size_t b64_len = read_next_b64_code(&b64_buf, &b64_max_len);
931 if (b64_len > 0) {
932 int ret;
933 size_t ssl_required_len = b64_len * 3 / 4 + 1;
934
935 /* Allocate more memory if necessary. */
936 if (ssl_required_len > ssl_max_len) {
937 void *ptr = realloc(ssl_buf, ssl_required_len);
938 if (NULL == ptr) {
939 printf_err(alloc_err);
940 fclose(b64_file);
941 b64_file = NULL;
942 break;
943 }
944 ssl_buf = ptr;
945 ssl_max_len = ssl_required_len;
946 }
947
948 printf("\nDeserializing number %u:\n", ++b64_counter);
949
950 printf("\nBase64 code:\n");
951 print_b64(b64_buf, b64_len);
952
953 ret = mbedtls_base64_decode(ssl_buf, ssl_max_len, &ssl_len, b64_buf, b64_len);
954 if (ret != 0) {
955 mbedtls_strerror(ret, (char *) b64_buf, b64_max_len);
956 printf_err("base64 code cannot be decoded - %s\n", b64_buf);
957 continue;
958 }
959
960 if (debug) {
961 printf("\nDecoded data in hex:\n\t");
962 print_hex(ssl_buf, ssl_len, 25, "\t");
963 }
964
965 print_deserialized_ssl_context(ssl_buf, ssl_len);
966
967 } else {
968 fclose(b64_file);
969 b64_file = NULL;
970 }
971 }
972
973 free(b64_buf);
974 free(ssl_buf);
975
976 if (b64_counter > 0) {
977 printf_dbg("Finished. Found %u base64 codes\n", b64_counter);
978 } else {
979 printf("Finished. No valid base64 code found\n");
980 }
981
982 mbedtls_psa_crypto_free();
983
984 return 0;
985 }
986
987 #endif /* MBEDTLS_X509_CRT_PARSE_C */
988