summaryrefslogtreecommitdiff
path: root/networking/tls.c
blob: 8bcaee9a6f885abfe364fc3c7cb4fc774aa7b341 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
/*
 * Copyright (C) 2017 Denys Vlasenko
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */
//config:config TLS
//config:	bool "tls (debugging)"
//config:	default n

//applet:IF_TLS(APPLET(tls, BB_DIR_USR_BIN, BB_SUID_DROP))

//kbuild:lib-$(CONFIG_TLS) += tls.o
//kbuild:lib-$(CONFIG_TLS) += tls_pstm.o
//kbuild:lib-$(CONFIG_TLS) += tls_pstm_montgomery_reduce.o
//kbuild:lib-$(CONFIG_TLS) += tls_pstm_mul_comba.o
//kbuild:lib-$(CONFIG_TLS) += tls_pstm_sqr_comba.o
//kbuild:lib-$(CONFIG_TLS) += tls_rsa.o
////kbuild:lib-$(CONFIG_TLS) += tls_ciphers.o
////kbuild:lib-$(CONFIG_TLS) += tls_aes.o
////kbuild:lib-$(CONFIG_TLS) += tls_aes_gcm.o

//usage:#define tls_trivial_usage
//usage:       "HOST[:PORT]"
//usage:#define tls_full_usage "\n\n"

#include "tls.h"

#define TLS_DEBUG 2

#if TLS_DEBUG
# define dbg(...) fprintf(stderr, __VA_ARGS__)
#else
# define dbg(...) ((void)0)
#endif

#define RECORD_TYPE_CHANGE_CIPHER_SPEC  20
#define RECORD_TYPE_ALERT               21
#define RECORD_TYPE_HANDSHAKE           22
#define RECORD_TYPE_APPLICATION_DATA    23

#define HANDSHAKE_HELLO_REQUEST         0
#define HANDSHAKE_CLIENT_HELLO          1
#define HANDSHAKE_SERVER_HELLO          2
#define HANDSHAKE_HELLO_VERIFY_REQUEST  3
#define HANDSHAKE_NEW_SESSION_TICKET    4
#define HANDSHAKE_CERTIFICATE           11
#define HANDSHAKE_SERVER_KEY_EXCHANGE   12
#define HANDSHAKE_CERTIFICATE_REQUEST   13
#define HANDSHAKE_SERVER_HELLO_DONE     14
#define HANDSHAKE_CERTIFICATE_VERIFY    15
#define HANDSHAKE_CLIENT_KEY_EXCHANGE   16
#define HANDSHAKE_FINISHED              20

#define SSL_HS_RANDOM_SIZE              32
#define SSL_HS_RSA_PREMASTER_SIZE       48

#define SSL_NULL_WITH_NULL_NULL                 0x0000
#define SSL_RSA_WITH_NULL_MD5                   0x0001
#define SSL_RSA_WITH_NULL_SHA                   0x0002
#define SSL_RSA_WITH_RC4_128_MD5                0x0004
#define SSL_RSA_WITH_RC4_128_SHA                0x0005
#define SSL_RSA_WITH_3DES_EDE_CBC_SHA           0x000A  /* 10 */
#define TLS_RSA_WITH_AES_128_CBC_SHA            0x002F  /* 47 */
#define TLS_RSA_WITH_AES_256_CBC_SHA            0x0035  /* 53 */
#define TLS_RSA_WITH_NULL_SHA256                0x003B  /* 59 */

#define TLS_EMPTY_RENEGOTIATION_INFO_SCSV       0x00FF

#define TLS_RSA_WITH_IDEA_CBC_SHA               0x0007  /* 7 */
#define SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA       0x0016  /* 22 */
#define SSL_DH_anon_WITH_RC4_128_MD5            0x0018  /* 24 */
#define SSL_DH_anon_WITH_3DES_EDE_CBC_SHA       0x001B  /* 27 */
#define TLS_DHE_RSA_WITH_AES_128_CBC_SHA        0x0033  /* 51 */
#define TLS_DHE_RSA_WITH_AES_256_CBC_SHA        0x0039  /* 57 */
#define TLS_DHE_RSA_WITH_AES_128_CBC_SHA256     0x0067  /* 103 */
#define TLS_DHE_RSA_WITH_AES_256_CBC_SHA256     0x006B  /* 107 */
#define TLS_DH_anon_WITH_AES_128_CBC_SHA        0x0034  /* 52 */
#define TLS_DH_anon_WITH_AES_256_CBC_SHA        0x003A  /* 58 */
#define TLS_RSA_WITH_AES_128_CBC_SHA256         0x003C  /* 60 */
#define TLS_RSA_WITH_AES_256_CBC_SHA256         0x003D  /* 61 */
#define TLS_RSA_WITH_SEED_CBC_SHA               0x0096  /* 150 */
#define TLS_PSK_WITH_AES_128_CBC_SHA            0x008C  /* 140 */
#define TLS_PSK_WITH_AES_128_CBC_SHA256         0x00AE  /* 174 */
#define TLS_PSK_WITH_AES_256_CBC_SHA384         0x00AF  /* 175 */
#define TLS_PSK_WITH_AES_256_CBC_SHA            0x008D  /* 141 */
#define TLS_DHE_PSK_WITH_AES_128_CBC_SHA        0x0090  /* 144 */
#define TLS_DHE_PSK_WITH_AES_256_CBC_SHA        0x0091  /* 145 */
#define TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA     0xC004  /* 49156 */
#define TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA     0xC005  /* 49157 */
#define TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA    0xC009  /* 49161 */
#define TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA    0xC00A  /* 49162 */
#define TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA     0xC012  /* 49170 */
#define TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA      0xC013  /* 49171 */
#define TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA      0xC014  /* 49172 */
#define TLS_ECDH_RSA_WITH_AES_128_CBC_SHA       0xC00E  /* 49166 */
#define TLS_ECDH_RSA_WITH_AES_256_CBC_SHA       0xC00F  /* 49167 */
#define TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 0xC023  /* 49187 */
#define TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 0xC024  /* 49188 */
#define TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256  0xC025  /* 49189 */
#define TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384  0xC026  /* 49190 */
#define TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256   0xC027  /* 49191 */
#define TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384   0xC028  /* 49192 */
#define TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256    0xC029  /* 49193 */
#define TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384    0xC02A  /* 49194 */

// RFC 5288 "AES Galois Counter Mode (GCM) Cipher Suites for TLS"
#define TLS_RSA_WITH_AES_128_GCM_SHA256         0x009C  /* 156 */
#define TLS_RSA_WITH_AES_256_GCM_SHA384         0x009D  /* 157 */
#define TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 0xC02B  /* 49195 */
#define TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 0xC02C  /* 49196 */
#define TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256  0xC02D  /* 49197 */
#define TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384  0xC02E  /* 49198 */
#define TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256   0xC02F  /* 49199 */
#define TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384   0xC030  /* 49200 */
#define TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256    0xC031  /* 49201 */
#define TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384    0xC032  /* 49202 */

//Tested against kernel.org:
//TLS 1.1
//#define TLS_MAJ 3
//#define TLS_MIN 2
//#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA // ok, recvs SERVER_KEY_EXCHANGE
//TLS 1.2
#define TLS_MAJ 3
#define TLS_MIN 3
//#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA // ok, recvs SERVER_KEY_EXCHANGE *** matrixssl uses this on my box
//#define CIPHER_ID TLS_RSA_WITH_AES_256_CBC_SHA256 // ok, no SERVER_KEY_EXCHANGE
// All GCMs:
//#define CIPHER_ID TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 // SSL_ALERT_HANDSHAKE_FAILURE
//#define CIPHER_ID TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
//#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 // ok, recvs SERVER_KEY_EXCHANGE
//#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
//#define CIPHER_ID TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384
//#define CIPHER_ID TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
//#define CIPHER_ID TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384
//#define CIPHER_ID TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
//#define CIPHER_ID TLS_RSA_WITH_AES_256_GCM_SHA384 // ok, no SERVER_KEY_EXCHANGE
//#define CIPHER_ID TLS_RSA_WITH_AES_128_GCM_SHA256 // ok, no SERVER_KEY_EXCHANGE *** select this?
#define CIPHER_ID TLS_RSA_WITH_NULL_SHA256 // for testing (does everything except encrypting)
//#define CIPHER_ID TLS_DH_anon_WITH_AES_256_CBC_SHA // SSL_ALERT_HANDSHAKE_FAILURE
//^^^^^^^^^^^^^^^^^^^^^^^ (tested b/c this one doesn't req server certs... no luck)
//test TLS_RSA_WITH_AES_128_CBC_SHA, in tls 1.2 it's mandated to be always supported

enum {
	SHA256_INSIZE = 64,
	SHA256_OUTSIZE = 32,
};

struct record_hdr {
	uint8_t type;
	uint8_t proto_maj, proto_min;
	uint8_t len16_hi, len16_lo;
};

typedef struct tls_state {
	int fd;

	psRsaKey_t server_rsa_pub_key;

	sha256_ctx_t handshake_sha256_ctx;

	uint8_t client_and_server_rand32[2 * 32];
	uint8_t master_secret[48];

	uint8_t encrypt_on_write;
	uint8_t decrypt_on_read;
	uint8_t client_write_MAC_key[SHA256_OUTSIZE];
// RFC 5246
// sequence number
// Each connection state contains a sequence number, which is
// maintained separately for read and write states.  The sequence
// number MUST be set to zero whenever a connection state is made the
// active state.  Sequence numbers are of type uint64 and may not
// exceed 2^64-1.
	uint64_t write_seq64_be;

	// RFC 5246
	// |6.2.1. Fragmentation
	// |  The record layer fragments information blocks into TLSPlaintext
	// |  records carrying data in chunks of 2^14 bytes or less.  Client
	// |  message boundaries are not preserved in the record layer (i.e.,
	// |  multiple client messages of the same ContentType MAY be coalesced
	// |  into a single TLSPlaintext record, or a single message MAY be
	// |  fragmented across several records)
	// |...
	// |  length
	// |    The length (in bytes) of the following TLSPlaintext.fragment.
	// |    The length MUST NOT exceed 2^14.
	// |...
	// | 6.2.2. Record Compression and Decompression
	// |...
	// |  Compression must be lossless and may not increase the content length
	// |  by more than 1024 bytes.  If the decompression function encounters a
	// |  TLSCompressed.fragment that would decompress to a length in excess of
	// |  2^14 bytes, it MUST report a fatal decompression failure error.
	// |...
	// |  length
	// |    The length (in bytes) of the following TLSCompressed.fragment.
	// |    The length MUST NOT exceed 2^14 + 1024.
	//
	// Since our buffer also contains 5-byte headers, make it a bit bigger:
	int insize;
	int tail;
	uint8_t inbuf[18*1024];
} tls_state_t;


static unsigned get24be(const uint8_t *p)
{
	return 0x100*(0x100*p[0] + p[1]) + p[2];
}

#if TLS_DEBUG
static void dump_hex(const char *fmt, const void *vp, int len)
{
	char hexbuf[32 * 1024 + 4];
	const uint8_t *p = vp;

	bin2hex(hexbuf, (void*)p, len)[0] = '\0';
	dbg(fmt, hexbuf);
}

static void dump_tls_record(const void *vp, int len)
{
	const uint8_t *p = vp;

	while (len > 0) {
		unsigned xhdr_len;
		if (len < 5) {
			dump_hex("< |%s|\n", p, len);
			return;
		}
		xhdr_len = 0x100*p[3] + p[4];
		dbg("< hdr_type:%u ver:%u.%u len:%u", p[0], p[1], p[2], xhdr_len);
		p += 5;
		len -= 5;
		if (len >= 4 && p[-5] == RECORD_TYPE_HANDSHAKE) {
			unsigned len24 = get24be(p + 1);
			dbg(" type:%u len24:%u", p[0], len24);
		}
		if (xhdr_len > len)
			xhdr_len = len;
		dump_hex(" |%s|\n", p, xhdr_len);
		p += xhdr_len;
		len -= xhdr_len;
	}
}
#endif

void tls_get_random(void *buf, unsigned len)
{
	if (len != open_read_close("/dev/urandom", buf, len))
		xfunc_die();
}

//TODO rename this to sha256_hash, and sha256_hash -> sha256_update
static void hash_sha256(uint8_t out[SHA256_OUTSIZE], const void *data, unsigned size)
{
	sha256_ctx_t ctx;
	sha256_begin(&ctx);
	sha256_hash(&ctx, data, size);
	sha256_end(&ctx, out);
}

/* Nondestructively see the current hash value */
static void sha256_peek(sha256_ctx_t *ctx, void *buffer)
{
	sha256_ctx_t ctx_copy = *ctx;
        sha256_end(&ctx_copy, buffer);
}

#if TLS_DEBUG >= 2
static void sha256_hash_dbg(const char *fmt, sha256_ctx_t *ctx, const void *buffer, size_t len)
{
        uint8_t h[SHA256_OUTSIZE];

	sha256_hash(ctx, buffer, len);
	dump_hex(fmt, buffer, len);
	dbg(" (%u) ", (int)len);
	sha256_peek(ctx, h);
	dump_hex("%s\n", h, SHA256_OUTSIZE);
}
#else
# define sha256_hash_dbg(fmt, ctx, buffer, len) \
         sha256_hash(ctx, buffer, len)
#endif /* not TLS_DEBUG >= 2 */

// RFC 2104
// HMAC(key, text) based on a hash H (say, sha256) is:
// ipad = [0x36 x INSIZE]
// opad = [0x5c x INSIZE]
// HMAC(key, text) = H((key XOR opad) + H((key XOR ipad) + text))
//
// H(key XOR opad) and H(key XOR ipad) can be precomputed
// if we often need HMAC hmac with the same key.
//
// text is often given in disjoint pieces.
static void hmac_sha256_precomputed_v(uint8_t out[SHA256_OUTSIZE],
		sha256_ctx_t *hashed_key_xor_ipad,
		sha256_ctx_t *hashed_key_xor_opad,
		va_list va)
{
	uint8_t *text;

	/* hashed_key_xor_ipad contains unclosed "H((key XOR ipad) +" state */
	/* hashed_key_xor_opad contains unclosed "H((key XOR opad) +" state */

	/* calculate out = H((key XOR ipad) + text) */
	while ((text = va_arg(va, uint8_t*)) != NULL) {
		unsigned text_size = va_arg(va, unsigned);
		sha256_hash(hashed_key_xor_ipad, text, text_size);
	}
	sha256_end(hashed_key_xor_ipad, out);

	/* out = H((key XOR opad) + out) */
	sha256_hash(hashed_key_xor_opad, out, SHA256_OUTSIZE);
	sha256_end(hashed_key_xor_opad, out);
}

static void hmac_sha256(uint8_t out[SHA256_OUTSIZE], uint8_t *key, unsigned key_size, ...)
{
	sha256_ctx_t hashed_key_xor_ipad;
	sha256_ctx_t hashed_key_xor_opad;
	uint8_t key_xor_ipad[SHA256_INSIZE];
	uint8_t key_xor_opad[SHA256_INSIZE];
	uint8_t tempkey[SHA256_OUTSIZE];
	va_list va;
	int i;

	va_start(va, key_size);

	// "The authentication key can be of any length up to INSIZE, the
	// block length of the hash function.  Applications that use keys longer
	// than INSIZE bytes will first hash the key using H and then use the
	// resultant OUTSIZE byte string as the actual key to HMAC."
	if (key_size > SHA256_INSIZE) {
		hash_sha256(tempkey, key, key_size);
		key = tempkey;
		key_size = SHA256_OUTSIZE;
	}

	for (i = 0; i < key_size; i++) {
		key_xor_ipad[i] = key[i] ^ 0x36;
		key_xor_opad[i] = key[i] ^ 0x5c;
	}
	for (; i < SHA256_INSIZE; i++) {
		key_xor_ipad[i] = 0x36;
		key_xor_opad[i] = 0x5c;
	}
	sha256_begin(&hashed_key_xor_ipad);
	sha256_hash(&hashed_key_xor_ipad, key_xor_ipad, SHA256_INSIZE);
	sha256_begin(&hashed_key_xor_opad);
	sha256_hash(&hashed_key_xor_opad, key_xor_opad, SHA256_INSIZE);

	hmac_sha256_precomputed_v(out, &hashed_key_xor_ipad, &hashed_key_xor_opad, va);
	va_end(va);
}

// RFC 5246:
// 5.  HMAC and the Pseudorandom Function
//...
// In this section, we define one PRF, based on HMAC.  This PRF with the
// SHA-256 hash function is used for all cipher suites defined in this
// document and in TLS documents published prior to this document when
// TLS 1.2 is negotiated.
//...
//    P_hash(secret, seed) = HMAC_hash(secret, A(1) + seed) +
//                           HMAC_hash(secret, A(2) + seed) +
//                           HMAC_hash(secret, A(3) + seed) + ...
// where + indicates concatenation.
// A() is defined as:
//    A(0) = seed
//    A(1) = HMAC_hash(secret, A(0)) = HMAC_hash(secret, seed)
//    A(i) = HMAC_hash(secret, A(i-1))
// P_hash can be iterated as many times as necessary to produce the
// required quantity of data.  For example, if P_SHA256 is being used to
// create 80 bytes of data, it will have to be iterated three times
// (through A(3)), creating 96 bytes of output data; the last 16 bytes
// of the final iteration will then be discarded, leaving 80 bytes of
// output data.
//
// TLS's PRF is created by applying P_hash to the secret as:
//
//    PRF(secret, label, seed) = P_<hash>(secret, label + seed)
//
// The label is an ASCII string.
static void prf_hmac_sha256(
		uint8_t *outbuf, unsigned outbuf_size,
		uint8_t *secret, unsigned secret_size,
		const char *label,
		uint8_t *seed, unsigned seed_size)
{
	uint8_t a[SHA256_OUTSIZE];
	uint8_t *out_p = outbuf;
	unsigned label_size = strlen(label);

	/* In P_hash() calculation, "seed" is "label + seed": */
#define SEED   label, label_size, seed, seed_size
#define SECRET secret, secret_size
#define A      a, (int)(sizeof(a))

	/* A(1) = HMAC_hash(secret, seed) */
	hmac_sha256(a, SECRET, SEED, NULL);
//TODO: convert hmac_sha256 to precomputed

	for(;;) {
		/* HMAC_hash(secret, A(1) + seed) */
		if (outbuf_size <= SHA256_OUTSIZE) {
			/* Last, possibly incomplete, block */
			/* (use a[] as temp buffer) */
			hmac_sha256(a, SECRET, A, SEED, NULL);
			memcpy(out_p, a, outbuf_size);
			return;
		}
		/* Not last block. Store directly to result buffer */
		hmac_sha256(out_p, SECRET, A, SEED, NULL);
		out_p += SHA256_OUTSIZE;
		outbuf_size -= SHA256_OUTSIZE;
		/* A(2) = HMAC_hash(secret, A(1)) */
		hmac_sha256(a, SECRET, A, NULL);
	}
#undef A
#undef SECRET
#undef SEED
}

static
tls_state_t *new_tls_state(void)
{
	tls_state_t *tls = xzalloc(sizeof(*tls));
	tls->fd = -1;
	sha256_begin(&tls->handshake_sha256_ctx);
	return tls;
}

static void tls_error_die(tls_state_t *tls)
{
	dump_tls_record(tls->inbuf, tls->insize + tls->tail);
	xfunc_die();
}

// RFC 5246
// 6.2.3.1.  Null or Standard Stream Cipher
//
// Stream ciphers (including BulkCipherAlgorithm.null; see Appendix A.6)
// convert TLSCompressed.fragment structures to and from stream
// TLSCiphertext.fragment structures.
//
//    stream-ciphered struct {
//        opaque content[TLSCompressed.length];
//        opaque MAC[SecurityParameters.mac_length];
//    } GenericStreamCipher;
//
// The MAC is generated as:
//    MAC(MAC_write_key, seq_num +
//                          TLSCompressed.type +
//                          TLSCompressed.version +
//                          TLSCompressed.length +
//                          TLSCompressed.fragment);
// where "+" denotes concatenation.
// seq_num
//    The sequence number for this record.
// MAC
//    The MAC algorithm specified by SecurityParameters.mac_algorithm.
//
// Note that the MAC is computed before encryption.  The stream cipher
// encrypts the entire block, including the MAC.
//...
// Appendix C.  Cipher Suite Definitions
//...
//                         Key      IV   Block
// Cipher        Type    Material  Size  Size
// ------------  ------  --------  ----  -----
// NULL          Stream      0       0    N/A
// RC4_128       Stream     16       0    N/A
// 3DES_EDE_CBC  Block      24       8      8
// AES_128_CBC   Block      16      16     16
// AES_256_CBC   Block      32      16     16
//
// MAC       Algorithm    mac_length  mac_key_length
// --------  -----------  ----------  --------------
// NULL      N/A              0             0
// MD5       HMAC-MD5        16            16
// SHA       HMAC-SHA1       20            20
// SHA256    HMAC-SHA256     32            32
static void xwrite_and_hash(tls_state_t *tls, /*const*/ void *buf, unsigned size)
{
	uint8_t mac_hash[SHA256_OUTSIZE];
	struct record_hdr *xhdr = buf;

	if (tls->encrypt_on_write) {
//TODO: convert hmac_sha256 to precomputed
		hmac_sha256(mac_hash,
			tls->client_write_MAC_key, sizeof(tls->client_write_MAC_key),
			&tls->write_seq64_be, sizeof(tls->write_seq64_be),
			buf, size,
		NULL);
		tls->write_seq64_be = SWAP_BE64(1 + SWAP_BE64(tls->write_seq64_be));
		/* Temporarily change for writing */
		xhdr->len16_lo += SHA256_OUTSIZE;
	}

	xwrite(tls->fd, buf, size);
	dbg("wrote %u bytes\n", size);

	if (tls->encrypt_on_write) {
		xwrite(tls->fd, mac_hash, sizeof(mac_hash));
		dbg("wrote %u bytes of hash\n", (int)sizeof(mac_hash));
		xhdr->len16_lo -= SHA256_OUTSIZE;
	}

	/* Handshake hash does not include record headers */
	if (size > 5 && xhdr->type == RECORD_TYPE_HANDSHAKE) {
		sha256_hash_dbg(">> sha256:%s", &tls->handshake_sha256_ctx, (uint8_t*)buf + 5, size - 5);
	}
}

static int xread_tls_block(tls_state_t *tls)
{
	struct record_hdr *xhdr;
	int len;
	int total;
	int target;

	dbg("insize:%u tail:%u\n", tls->insize, tls->tail);
	memmove(tls->inbuf, tls->inbuf + tls->insize, tls->tail);
	errno = 0;
	total = tls->tail;
	target = sizeof(tls->inbuf);
	for (;;) {
		if (total >= sizeof(*xhdr) && target == sizeof(tls->inbuf)) {
			xhdr = (void*)tls->inbuf;
			target = sizeof(*xhdr) + (0x100 * xhdr->len16_hi + xhdr->len16_lo);
			if (target >= sizeof(tls->inbuf)) {
				/* malformed input (too long): yell and die */
				tls->tail = 0;
				tls->insize = total;
				tls_error_die(tls);
			}
			// can also check type/proto_maj/proto_min here
		}
		/* if total >= target, we have a full packet (and possibly more)... */
		if (total - target >= 0)
			break;
		len = safe_read(tls->fd, tls->inbuf + total, sizeof(tls->inbuf) - total);
		if (len <= 0)
			bb_perror_msg_and_die("short read");
		total += len;
	}
	tls->tail = total - target;
	tls->insize = target;
	target -= sizeof(*xhdr);

	/* RFC 5246 is not saying it explicitly, but sha256 hash
	 * in our FINISHED record must include data of incoming packets too!
	 */
	if (tls->inbuf[0] == RECORD_TYPE_HANDSHAKE) {
		sha256_hash_dbg("<< sha256:%s", &tls->handshake_sha256_ctx, tls->inbuf + 5, target);
	}

	dbg("got block len:%u\n", target);
	return target;
}

/*
 * DER parsing routines
 */
static unsigned get_der_len(uint8_t **bodyp, uint8_t *der, uint8_t *end)
{
	unsigned len, len1;

	if (end - der < 2)
		xfunc_die();
//	if ((der[0] & 0x1f) == 0x1f) /* not single-byte item code? */
//		xfunc_die();

	len = der[1]; /* maybe it's short len */
	if (len >= 0x80) {
		/* no, it's long */

		if (len == 0x80 || end - der < (int)(len - 0x7e)) {
			/* 0x80 is "0 bytes of len", invalid DER: must use short len if can */
			/* need 3 or 4 bytes for 81, 82 */
			xfunc_die();
		}

		len1 = der[2]; /* if (len == 0x81) it's "ii 81 xx", fetch xx */
		if (len > 0x82) {
			/* >0x82 is "3+ bytes of len", should not happen realistically */
			xfunc_die();
		}
		if (len == 0x82) { /* it's "ii 82 xx yy" */
			len1 = 0x100*len1 + der[3];
			der += 1; /* skip [yy] */
		}
		der += 1; /* skip [xx] */
		len = len1;
//		if (len < 0x80)
//			xfunc_die(); /* invalid DER: must use short len if can */
	}
	der += 2; /* skip [code]+[1byte] */

	if (end - der < (int)len)
		xfunc_die();
	*bodyp = der;

	return len;
}

static uint8_t *enter_der_item(uint8_t *der, uint8_t **endp)
{
	uint8_t *new_der;
	unsigned len = get_der_len(&new_der, der, *endp);
	dbg("entered der @%p:0x%02x len:%u inner_byte @%p:0x%02x\n", der, der[0], len, new_der, new_der[0]);
	/* Move "end" position to cover only this item */
	*endp = new_der + len;
	return new_der;
}

static uint8_t *skip_der_item(uint8_t *der, uint8_t *end)
{
	uint8_t *new_der;
	unsigned len = get_der_len(&new_der, der, end);
	/* Skip body */
	new_der += len;
	dbg("skipped der 0x%02x, next byte 0x%02x\n", der[0], new_der[0]);
	return new_der;
}

static void der_binary_to_pstm(pstm_int *pstm_n, uint8_t *der, uint8_t *end)
{
	uint8_t *bin_ptr;
	unsigned len = get_der_len(&bin_ptr, der, end);

	dbg("binary bytes:%u, first:0x%02x\n", len, bin_ptr[0]);
	pstm_init_for_read_unsigned_bin(/*pool:*/ NULL, pstm_n, len);
	pstm_read_unsigned_bin(pstm_n, bin_ptr, len);
	//return bin + len;
}

static void find_key_in_der_cert(tls_state_t *tls, uint8_t *der, int len)
{
/* Certificate is a DER-encoded data structure. Each DER element has a length,
 * which makes it easy to skip over large compound elements of any complexity
 * without parsing them. Example: partial decode of kernel.org certificate:
 *  SEQ 0x05ac/1452 bytes (Certificate): 308205ac
 *    SEQ 0x0494/1172 bytes (tbsCertificate): 30820494
 *      [ASN_CONTEXT_SPECIFIC | ASN_CONSTRUCTED | 0] 3 bytes: a003
 *        INTEGER (version): 0201 02
 *      INTEGER 0x11 bytes (serialNumber): 0211 00 9f85bf664b0cddafca508679501b2be4
 *      //^^^^^^note: matrixSSL also allows [ASN_CONTEXT_SPECIFIC | ASN_PRIMITIVE | 2] = 0x82 type
 *      SEQ 0x0d bytes (signatureAlgo): 300d
 *        OID 9 bytes: 0609 2a864886f70d01010b (OID_SHA256_RSA_SIG 42.134.72.134.247.13.1.1.11)
 *        NULL: 0500
 *      SEQ 0x5f bytes (issuer): 305f
 *        SET 11 bytes: 310b
 *          SEQ 9 bytes: 3009
 *            OID 3 bytes: 0603 550406
 *            Printable string "FR": 1302 4652
 *        SET 14 bytes: 310e
 *          SEQ 12 bytes: 300c
 *            OID 3 bytes: 0603 550408
 *            Printable string "Paris": 1305 5061726973
 *        SET 14 bytes: 310e
 *          SEQ 12 bytes: 300c
 *            OID 3 bytes: 0603 550407
 *            Printable string "Paris": 1305 5061726973
 *        SET 14 bytes: 310e
 *          SEQ 12 bytes: 300c
 *            OID 3 bytes: 0603 55040a
 *            Printable string "Gandi": 1305 47616e6469
 *        SET 32 bytes: 3120
 *          SEQ 30 bytes: 301e
 *            OID 3 bytes: 0603 550403
 *            Printable string "Gandi Standard SSL CA 2": 1317 47616e6469205374616e646172642053534c2043412032
 *      SEQ 30 bytes (validity): 301e
 *        TIME "161011000000Z": 170d 3136313031313030303030305a
 *        TIME "191011235959Z": 170d 3139313031313233353935395a
 *      SEQ 0x5b/91 bytes (subject): 305b //I did not decode this
 *          3121301f060355040b1318446f6d61696e20436f
 *          6e74726f6c2056616c6964617465643121301f06
 *          0355040b1318506f73697469766553534c204d75
 *          6c74692d446f6d61696e31133011060355040313
 *          0a6b65726e656c2e6f7267
 *      SEQ 0x01a2/418 bytes (subjectPublicKeyInfo): 308201a2
 *        SEQ 13 bytes (algorithm): 300d
 *          OID 9 bytes: 0609 2a864886f70d010101 (OID_RSA_KEY_ALG 42.134.72.134.247.13.1.1.1)
 *          NULL: 0500
 *        BITSTRING 0x018f/399 bytes (publicKey): 0382018f
 *          ????: 00
 *          //after the zero byte, it appears key itself uses DER encoding:
 *          SEQ 0x018a/394 bytes: 3082018a
 *            INTEGER 0x0181/385 bytes (modulus): 02820181
 *                  00b1ab2fc727a3bef76780c9349bf3
 *                  ...24 more blocks of 15 bytes each...
 *                  90e895291c6bc8693b65
 *            INTEGER 3 bytes (exponent): 0203 010001
 *      [ASN_CONTEXT_SPECIFIC | ASN_CONSTRUCTED | 0x3] 0x01e5 bytes (X509v3 extensions): a38201e5
 *        SEQ 0x01e1 bytes: 308201e1
 *        ...
 * Certificate is a sequence of three elements:
 *	tbsCertificate (SEQ)
 *	signatureAlgorithm (AlgorithmIdentifier)
 *	signatureValue (BIT STRING)
 *
 * In turn, tbsCertificate is a sequence of:
 *	version
 *	serialNumber
 *	signatureAlgo (AlgorithmIdentifier)
 *	issuer (Name, has complex structure)
 *	validity (Validity, SEQ of two Times)
 *	subject (Name)
 *	subjectPublicKeyInfo (SEQ)
 *	...
 *
 * subjectPublicKeyInfo is a sequence of:
 *	algorithm (AlgorithmIdentifier)
 *	publicKey (BIT STRING)
 *
 * We need Certificate.tbsCertificate.subjectPublicKeyInfo.publicKey
 */
	uint8_t *end = der + len;

	/* enter "Certificate" item: [der, end) will be only Cert */
	der = enter_der_item(der, &end);

	/* enter "tbsCertificate" item: [der, end) will be only tbsCert */
	der = enter_der_item(der, &end);

	/* skip up to subjectPublicKeyInfo */
	der = skip_der_item(der, end); /* version */
	der = skip_der_item(der, end); /* serialNumber */
	der = skip_der_item(der, end); /* signatureAlgo */
	der = skip_der_item(der, end); /* issuer */
	der = skip_der_item(der, end); /* validity */
	der = skip_der_item(der, end); /* subject */

	/* enter subjectPublicKeyInfo */
	der = enter_der_item(der, &end);
	{ /* check subjectPublicKeyInfo.algorithm */
		static const uint8_t expected[] = {
			0x30,0x0d, // SEQ 13 bytes
			0x06,0x09, 0x2a,0x86,0x48,0x86,0xf7,0x0d,0x01,0x01,0x01, // OID RSA_KEY_ALG 42.134.72.134.247.13.1.1.1
			//0x05,0x00, // NULL
		};
		if (memcmp(der, expected, sizeof(expected)) != 0)
			bb_error_msg_and_die("not RSA key");
	}
	/* skip subjectPublicKeyInfo.algorithm */
	der = skip_der_item(der, end);
	/* enter subjectPublicKeyInfo.publicKey */
//	die_if_not_this_der_type(der, end, 0x03); /* must be BITSTRING */
	der = enter_der_item(der, &end);

	/* parse RSA key: */
//based on getAsnRsaPubKey(), pkcs1ParsePrivBin() is also of note
	dbg("key bytes:%u, first:0x%02x\n", (int)(end - der), der[0]);
	if (end - der < 14) xfunc_die();
	/* example format:
	 * ignore bits: 00
	 * SEQ 0x018a/394 bytes: 3082018a
	 *   INTEGER 0x0181/385 bytes (modulus): 02820181 XX...XXX
	 *   INTEGER 3 bytes (exponent): 0203 010001
	 */
	if (*der != 0) /* "ignore bits", should be 0 */
		xfunc_die();
	der++;
	der = enter_der_item(der, &end); /* enter SEQ */
	/* memset(tls->server_rsa_pub_key, 0, sizeof(tls->server_rsa_pub_key)); - already is */
	der_binary_to_pstm(&tls->server_rsa_pub_key.N, der, end); /* modulus */
	der = skip_der_item(der, end);
	der_binary_to_pstm(&tls->server_rsa_pub_key.e, der, end); /* exponent */
	tls->server_rsa_pub_key.size = pstm_unsigned_bin_size(&tls->server_rsa_pub_key.N);
	dbg("server_rsa_pub_key.size:%d\n", tls->server_rsa_pub_key.size);
}

/*
 * TLS Handshake routines
 */
static int xread_tls_handshake_block(tls_state_t *tls, int min_len)
{
	struct record_hdr *xhdr;
	int len = xread_tls_block(tls);

	xhdr = (void*)tls->inbuf;
	if (len < min_len
	 || xhdr->type != RECORD_TYPE_HANDSHAKE
	 || xhdr->proto_maj != TLS_MAJ
	 || xhdr->proto_min != TLS_MIN
	) {
		tls_error_die(tls);
	}
	dbg("got HANDSHAKE\n");
	return len;
}

static void fill_handshake_record_hdr(struct record_hdr *xhdr, unsigned len)
{
	struct handshake_hdr {
		struct record_hdr xhdr;
		uint8_t type;
		uint8_t len24_hi, len24_mid, len24_lo;
	} *h = (void*)xhdr;

	h->xhdr.type = RECORD_TYPE_HANDSHAKE;
	h->xhdr.proto_maj = TLS_MAJ;
	h->xhdr.proto_min = TLS_MIN;
	len -= 5;
	h->xhdr.len16_hi = len >> 8;
	// can be optimized to do one store instead of four:
	// uint32_t v = htonl(0x100*(RECORD_TYPE_HANDSHAKE + 0x100*(TLS_MAJ + 0x100*(TLS_MIN))))
	//            | ((len >> 8) << 24); // little-endian specific, don't use in this form
	// *(uint32_t *)xhdr = v;

	h->xhdr.len16_lo = len & 0xff;

	len -= 4;
	h->len24_hi  = len >> 16;
	h->len24_mid = len >> 8;
	h->len24_lo  = len & 0xff;

	memset(h + 1, 0, len);
}

//TODO: implement RFC 5746 (Renegotiation Indication Extension) - some servers will refuse to work with us otherwise
static void send_client_hello(tls_state_t *tls)
{
	struct client_hello {
		struct record_hdr xhdr;
		uint8_t type;
		uint8_t len24_hi, len24_mid, len24_lo;
		uint8_t proto_maj, proto_min;
		uint8_t rand32[32];
		uint8_t session_id_len;
		/* uint8_t session_id[]; */
		uint8_t cipherid_len16_hi, cipherid_len16_lo;
		uint8_t cipherid[2 * 1]; /* actually variable */
		uint8_t comprtypes_len;
		uint8_t comprtypes[1]; /* actually variable */
	};
	struct client_hello record;

	fill_handshake_record_hdr(&record.xhdr, sizeof(record));
	record.type = HANDSHAKE_CLIENT_HELLO;
	record.proto_maj = TLS_MAJ;	/* the "requested" version of the protocol, */
	record.proto_min = TLS_MIN;	/* can be higher than one in record headers */
	tls_get_random(record.rand32, sizeof(record.rand32));
	/* record.session_id_len = 0; - already is */
	/* record.cipherid_len16_hi = 0; */
	record.cipherid_len16_lo = 2 * 1;
	record.cipherid[0] = CIPHER_ID >> 8;
	record.cipherid[1] = CIPHER_ID & 0xff;
	record.comprtypes_len = 1;
	/* record.comprtypes[0] = 0; */

	//dbg (make it repeatable): memset(record.rand32, 0x11, sizeof(record.rand32));
	dbg(">> HANDSHAKE_CLIENT_HELLO\n");
	xwrite_and_hash(tls, &record, sizeof(record));
	memcpy(tls->client_and_server_rand32, record.rand32, sizeof(record.rand32));
}

static void get_server_hello(tls_state_t *tls)
{
	struct server_hello {
		struct record_hdr xhdr;
		uint8_t type;
		uint8_t len24_hi, len24_mid, len24_lo;
		uint8_t proto_maj, proto_min;
		uint8_t rand32[32]; /* first 4 bytes are unix time in BE format */
		uint8_t session_id_len;
		uint8_t session_id[32];
		uint8_t cipherid_hi, cipherid_lo;
		uint8_t comprtype;
		/* extensions may follow, but only those which client offered in its Hello */
	};
	struct server_hello *hp;
	uint8_t *cipherid;

	xread_tls_handshake_block(tls, 74);

	hp = (void*)tls->inbuf;
	// 74 bytes:
	// 02  000046 03|03   58|78|cf|c1 50|a5|49|ee|7e|29|48|71|fe|97|fa|e8|2d|19|87|72|90|84|9d|37|a3|f0|cb|6f|5f|e3|3c|2f |20  |d8|1a|78|96|52|d6|91|01|24|b3|d6|5b|b7|d0|6c|b3|e1|78|4e|3c|95|de|74|a0|ba|eb|a7|3a|ff|bd|a2|bf |00|9c |00|
	//SvHl len=70 maj.min unixtime^^^ 28randbytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^ slen sid32bytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cipSel comprSel
	if (hp->type != HANDSHAKE_SERVER_HELLO
	 || hp->len24_hi  != 0
	 || hp->len24_mid != 0
	 /* hp->len24_lo checked later */
	 || hp->proto_maj != TLS_MAJ
	 || hp->proto_min != TLS_MIN
	) {
		tls_error_die(tls);
	}

	cipherid = &hp->cipherid_hi;
	if (hp->session_id_len != 32) {
		if (hp->session_id_len != 0)
			tls_error_die(tls);

		// session_id_len == 0: no session id
		// "The server
		// may return an empty session_id to indicate that the session will
		// not be cached and therefore cannot be resumed."
		cipherid -= 32;
		hp->len24_lo += 32; /* what len would be if session id would be present */
	}

	if (hp->len24_lo < 70
	 || cipherid[0]  != (CIPHER_ID >> 8)
	 || cipherid[1]  != (CIPHER_ID & 0xff)
	 || cipherid[2]  != 0 /* comprtype */
	) {
		tls_error_die(tls);
	}

	dbg("<< SERVER_HELLO\n");
	memcpy(tls->client_and_server_rand32 + 32, hp->rand32, sizeof(hp->rand32));
}

static void get_server_cert(tls_state_t *tls)
{
	struct record_hdr *xhdr;
	uint8_t *certbuf;
	int len, len1;

	len = xread_tls_handshake_block(tls, 10);

	xhdr = (void*)tls->inbuf;
	certbuf = (void*)(xhdr + 1);
	if (certbuf[0] != HANDSHAKE_CERTIFICATE)
		tls_error_die(tls);
	dbg("<< CERTIFICATE\n");
	// 4392 bytes:
	// 0b  00|11|24 00|11|21 00|05|b0 30|82|05|ac|30|82|04|94|a0|03|02|01|02|02|11|00|9f|85|bf|66|4b|0c|dd|af|ca|50|86|79|50|1b|2b|e4|30|0d...
	//Cert len=4388 ChainLen CertLen^ DER encoded X509 starts here. openssl x509 -in FILE -inform DER -noout -text
	len1 = get24be(certbuf + 1);
	if (len1 > len - 4) tls_error_die(tls);
	len = len1;
	len1 = get24be(certbuf + 4);
	if (len1 > len - 3) tls_error_die(tls);
	len = len1;
	len1 = get24be(certbuf + 7);
	if (len1 > len - 3) tls_error_die(tls);
	len = len1;

	if (len)
		find_key_in_der_cert(tls, certbuf + 10, len);
}

static void send_client_key_exchange(tls_state_t *tls)
{
	struct client_key_exchange {
		struct record_hdr xhdr;
		uint8_t type;
		uint8_t len24_hi, len24_mid, len24_lo;
		/* keylen16 exists for RSA (in TLS, not in SSL), but not for some other key types */
		uint8_t keylen16_hi, keylen16_lo;
		uint8_t key[4 * 1024]; // size??
	};
	struct client_key_exchange record;
	uint8_t rsa_premaster[SSL_HS_RSA_PREMASTER_SIZE];
	int len;

	fill_handshake_record_hdr(&record.xhdr, sizeof(record) - sizeof(record.key));
	record.type = HANDSHAKE_CLIENT_KEY_EXCHANGE;

	tls_get_random(rsa_premaster, sizeof(rsa_premaster));
	// RFC 5246
	// "Note: The version number in the PreMasterSecret is the version
	// offered by the client in the ClientHello.client_version, not the
	// version negotiated for the connection."
	rsa_premaster[0] = TLS_MAJ;
	rsa_premaster[1] = TLS_MIN;
	len = psRsaEncryptPub(/*pool:*/ NULL,
		/* psRsaKey_t* */ &tls->server_rsa_pub_key,
		rsa_premaster, /*inlen:*/ sizeof(rsa_premaster),
		record.key, sizeof(record.key),
		data_param_ignored
	);
	/* length fields need fixing */
	record.keylen16_hi = len >> 8;
	record.keylen16_lo = len & 0xff;
	len += 2;
	/* record.len24_hi  = 0; - already is */
	record.len24_mid = len >> 8;
	record.len24_lo  = len & 0xff;
	len += 4;
	record.xhdr.len16_hi = len >> 8;
	record.xhdr.len16_lo = len & 0xff;

	dbg(">> HANDSHAKE_CLIENT_KEY_EXCHANGE\n");
	xwrite_and_hash(tls, &record, sizeof(record.xhdr) + len);

	// RFC 5246
	// For all key exchange methods, the same algorithm is used to convert
	// the pre_master_secret into the master_secret.  The pre_master_secret
	// should be deleted from memory once the master_secret has been
	// computed.
	//      master_secret = PRF(pre_master_secret, "master secret",
	//                          ClientHello.random + ServerHello.random)
	//                          [0..47];
	// The master secret is always exactly 48 bytes in length.  The length
	// of the premaster secret will vary depending on key exchange method.
	prf_hmac_sha256(
		tls->master_secret, sizeof(tls->master_secret),
		rsa_premaster, sizeof(rsa_premaster),
		"master secret",
		tls->client_and_server_rand32, sizeof(tls->client_and_server_rand32)
	);
	dump_hex("master secret:%s\n", tls->master_secret, sizeof(tls->master_secret));

	// RFC 5246
	// 6.3.  Key Calculation
	//
	// The Record Protocol requires an algorithm to generate keys required
	// by the current connection state (see Appendix A.6) from the security
	// parameters provided by the handshake protocol.
	//
	// The master secret is expanded into a sequence of secure bytes, which
	// is then split to a client write MAC key, a server write MAC key, a
	// client write encryption key, and a server write encryption key.  Each
	// of these is generated from the byte sequence in that order.  Unused
	// values are empty.  Some AEAD ciphers may additionally require a
	// client write IV and a server write IV (see Section 6.2.3.3).
	//
	// When keys and MAC keys are generated, the master secret is used as an
	// entropy source.
	//
	// To generate the key material, compute
	//
	//    key_block = PRF(SecurityParameters.master_secret,
	//                    "key expansion",
	//                    SecurityParameters.server_random +
	//                    SecurityParameters.client_random);
	//
	// until enough output has been generated.  Then, the key_block is
	// partitioned as follows:
	//
	//    client_write_MAC_key[SecurityParameters.mac_key_length]
	//    server_write_MAC_key[SecurityParameters.mac_key_length]
	//    client_write_key[SecurityParameters.enc_key_length]
	//    server_write_key[SecurityParameters.enc_key_length]
	//    client_write_IV[SecurityParameters.fixed_iv_length]
	//    server_write_IV[SecurityParameters.fixed_iv_length]
	{
		uint8_t tmp64[64];
		/* make server_rand32 + client_rand32 */
		memcpy(&tmp64[0] , &tls->client_and_server_rand32[32], 32);
		memcpy(&tmp64[32], &tls->client_and_server_rand32[0] , 32);

		prf_hmac_sha256(
			tls->client_write_MAC_key, sizeof(tls->client_write_MAC_key),
			tls->master_secret, sizeof(tls->master_secret),
			"key expansion",
			tmp64, 64
		);
		dump_hex("client_write_MAC_key:%s\n",
			tls->client_write_MAC_key, sizeof(tls->client_write_MAC_key)
		);
	}
}

static const uint8_t rec_CHANGE_CIPHER_SPEC[] = {
	RECORD_TYPE_CHANGE_CIPHER_SPEC, TLS_MAJ, TLS_MIN, 00, 01,
	01
};

static void send_change_cipher_spec(tls_state_t *tls)
{
	/* Not "xwrite_and_hash": this is not a handshake message */
	dbg(">> CHANGE_CIPHER_SPEC\n");
	xwrite(tls->fd, rec_CHANGE_CIPHER_SPEC, sizeof(rec_CHANGE_CIPHER_SPEC));

	/* tls->write_seq64_be = 0; - already is */
	tls->encrypt_on_write = 1;
}

// 7.4.9.  Finished
// A Finished message is always sent immediately after a change
// cipher spec message to verify that the key exchange and
// authentication processes were successful.  It is essential that a
// change cipher spec message be received between the other handshake
// messages and the Finished message.
//...
// The Finished message is the first one protected with the just
// negotiated algorithms, keys, and secrets.  Recipients of Finished
// messages MUST verify that the contents are correct.  Once a side
// has sent its Finished message and received and validated the
// Finished message from its peer, it may begin to send and receive
// application data over the connection.
//...
// struct {
//     opaque verify_data[verify_data_length];
// } Finished;
//
// verify_data
//    PRF(master_secret, finished_label, Hash(handshake_messages))
//       [0..verify_data_length-1];
//
// finished_label
//    For Finished messages sent by the client, the string
//    "client finished".  For Finished messages sent by the server,
//    the string "server finished".
//
// Hash denotes a Hash of the handshake messages.  For the PRF
// defined in Section 5, the Hash MUST be the Hash used as the basis
// for the PRF.  Any cipher suite which defines a different PRF MUST
// also define the Hash to use in the Finished computation.
//
// In previous versions of TLS, the verify_data was always 12 octets
// long.  In the current version of TLS, it depends on the cipher
// suite.  Any cipher suite which does not explicitly specify
// verify_data_length has a verify_data_length equal to 12.  This
// includes all existing cipher suites.
static void send_client_finished(tls_state_t *tls)
{
	struct client_finished {
		struct record_hdr xhdr;
		uint8_t type;
		uint8_t len24_hi, len24_mid, len24_lo;
		uint8_t prf_result[12];
	};
	struct client_finished record;
	uint8_t handshake_hash[SHA256_OUTSIZE];

	fill_handshake_record_hdr(&record.xhdr, sizeof(record));
	record.type = HANDSHAKE_FINISHED;

	sha256_peek(&tls->handshake_sha256_ctx, handshake_hash);
	prf_hmac_sha256(record.prf_result, sizeof(record.prf_result),
			tls->master_secret, sizeof(tls->master_secret),
			"client finished",
			handshake_hash, sizeof(handshake_hash)
	);
	dump_hex("from secret: %s\n", tls->master_secret, sizeof(tls->master_secret));
	dump_hex("from labelSeed: %s", "client finished", sizeof("client finished")-1);
			dump_hex("%s\n", handshake_hash, sizeof(handshake_hash));
	dump_hex("=> digest: %s\n", record.prf_result, sizeof(record.prf_result));

//(1) TODO: well, this should be encrypted on send, really.
//(2) do we really need to also hash it?

	dbg(">> HANDSHAKE_FINISHED\n");
	xwrite_and_hash(tls, &record, sizeof(record));
}

static void tls_handshake(tls_state_t *tls)
{
	// Client              RFC 5246                Server
	// (*) - optional messages, not always sent
	//
	// ClientHello          ------->
	//                                        ServerHello
	//                                       Certificate*
	//                                 ServerKeyExchange*
	//                                CertificateRequest*
	//                      <-------      ServerHelloDone
	// Certificate*
	// ClientKeyExchange
	// CertificateVerify*
	// [ChangeCipherSpec]
	// Finished             ------->
	//                                 [ChangeCipherSpec]
	//                      <-------             Finished
	// Application Data     <------>     Application Data
	int len;

	send_client_hello(tls);
	get_server_hello(tls);

	//RFC 5246
	// The server MUST send a Certificate message whenever the agreed-
	// upon key exchange method uses certificates for authentication
	// (this includes all key exchange methods defined in this document
	// except DH_anon).  This message will always immediately follow the
	// ServerHello message.
	//
	// IOW: in practice, Certificate *always* follows.
	// (for example, kernel.org does not even accept DH_anon cipher id)
	get_server_cert(tls);

	len = xread_tls_handshake_block(tls, 4);
	if (tls->inbuf[5] == HANDSHAKE_SERVER_KEY_EXCHANGE) {
		// 459 bytes:
		// 0c   00|01|c7 03|00|17|41|04|87|94|2e|2f|68|d0|c9|f4|97|a8|2d|ef|ed|67|ea|c6|f3|b3|56|47|5d|27|b6|bd|ee|70|25|30|5e|b0|8e|f6|21|5a...
		//SvKey len=455^
		// with TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA: 461 bytes:
		// 0c   00|01|c9 03|00|17|41|04|cd|9b|b4|29|1f|f6|b0|c2|84|82|7f|29|6a|47|4e|ec|87|0b|c1|9c|69|e1|f8|c6|d0|53|e9|27|90|a5|c8|02|15|75...
		dbg("<< SERVER_KEY_EXCHANGE len:%u\n", len);
//probably need to save it
		xread_tls_handshake_block(tls, 4);
	}

//	if (tls->inbuf[5] == HANDSHAKE_CERTIFICATE_REQUEST) {
//		dbg("<< CERTIFICATE_REQUEST\n");
//RFC 5246: (in response to this,) "If no suitable certificate is available,
// the client MUST send a certificate message containing no
// certificates.  That is, the certificate_list structure has a
// length of zero. ...
// Client certificates are sent using the Certificate structure
// defined in Section 7.4.2."
// (i.e. the same format as server certs)
//		xread_tls_handshake_block(tls, 4);
//	}

	if (tls->inbuf[5] != HANDSHAKE_SERVER_HELLO_DONE)
		tls_error_die(tls);
	// 0e 000000 (len:0)
	dbg("<< SERVER_HELLO_DONE\n");

	send_client_key_exchange(tls);

	send_change_cipher_spec(tls);
	/* we now should send encrypted... as soon as we grok AES. */

	send_client_finished(tls);

	/* Get CHANGE_CIPHER_SPEC */
	len = xread_tls_block(tls);
	if (len != 1 || memcmp(tls->inbuf, rec_CHANGE_CIPHER_SPEC, 6) != 0)
		tls_error_die(tls);
	dbg("<< CHANGE_CIPHER_SPEC\n");
	tls->decrypt_on_read = 1;
	/* we now should receive encrypted */

	/* Get (encrypted) FINISHED from the server */
	len = xread_tls_block(tls);
	if (len < 4 || tls->inbuf[5] != HANDSHAKE_FINISHED)
		tls_error_die(tls);
	dbg("<< FINISHED\n");
	/* application data can be sent/received */
}

// To run a test server using openssl:
// openssl s_server -key key.pem -cert server.pem -debug -tls1_2 -no_tls1 -no_tls1_1
// openssl req -x509 -newkey rsa:$((4096/4*3)) -keyout key.pem -out server.pem -nodes -days 99999 -subj '/CN=localhost'

int tls_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int tls_main(int argc UNUSED_PARAM, char **argv)
{
	tls_state_t *tls;
	len_and_sockaddr *lsa;
	int fd;

	// INIT_G();
	// getopt32(argv, "myopts")

	if (!argv[1])
		bb_show_usage();

	lsa = xhost2sockaddr(argv[1], 443);
	fd = xconnect_stream(lsa);

	tls = new_tls_state();
	tls->fd = fd;
	tls_handshake(tls);

	return EXIT_SUCCESS;
}

/* Unencryped SHA256 example:
 * $ openssl req -x509 -newkey rsa:$((4096/4*3)) -keyout key.pem -out server.pem -nodes -days 99999 -subj '/CN=localhost'
 * $ openssl s_server -key key.pem -cert server.pem -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher NULL
 * $ openssl s_client -connect 127.0.0.1:4433 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher NULL-SHA256
 *           s_client says:

write to 0x1d750b0 [0x1e6f153] (99 bytes => 99 (0x63))
0000 - 16 03 01 005e  01 00005a   0303 [4d ef 5c 82 3e   ....^...Z..M.\.> >> ClHello
0010 - bf a6 ee f1 1e 04 d1 5c-99 20 86 13 e9 0a cf 58   .......\. .....X
0020 - 75 b1 bd 7a e6 d6 44 f3-d3 a1 52] 00 0004 003b    u..z..D...R....; 003b = TLS_RSA_WITH_NULL_SHA256
0030 - 00ff                                                                       TLS_EMPTY_RENEGOTIATION_INFO_SCSV
             0100                                                             compr=none
                   002d, 0023  0000, 000d  0020 [00 1e   .....-.#..... .. extlen, SessionTicketTLS 0 bytes, SignatureAlgorithms 32 bytes
0040 - 06 01 06 02 06 03 05 01-05 02 05 03 04 01 04 02   ................
0050 - 04 03 03 01 03 02 03 03-02 01 02 02 02 03] 000f   ................ Heart Beat 1 byte
0060 - 0001  01                                          ...

read from 0x1d750b0 [0x1e6ac03] (5 bytes => 5 (0x5))
0000 - 16 03 03 00 3a                                    ....:
read from 0x1d750b0 [0x1e6ac08] (58 bytes => 58 (0x3A))
0000 - 02 000036   0303  [f2 61-ae c8 58 e3 51 42 32 93   ...6...a..X.QB2. << SvHello
0010 - c5 62 e4 f5 06 93 81 65-aa f7 df 74 af 7c 98 b4   .b.....e...t.|..
0020 - 3e a7 35 c3 25 69] 00,003b,00..................   >.5.%i..;....... - no session id! "The server
									may return an empty session_id to indicate that the session will
									not be cached and therefore cannot be resumed."
									003b = TLS_RSA_WITH_NULL_SHA256 accepted, 00 - no compr
                                     000e  ff01  0001                 extlen, 0xff01=RenegotiationInfo 1 byte
0030 - 00, 0023 0000,                                                SessionTicketTLS 0 bytes
                       000f 0001 01                     ..#.......       Heart Beat 1 byte

read from 0x1d750b0 [0x1e6ac03] (5 bytes => 5 (0x5))
0000 - 16 03 03 04 0b                                    .....
read from 0x1d750b0 [0x1e6ac08] (1035 bytes => 1035 (0x40B))
0000 - 0b 00 04 07 00 04 04 00-04 01 30 82 03 fd 30 82   ..........0...0. << Cert
0010 - 02 65 a0 03 02 01 02 02-09 00 d9 d9 8d b8 94 ad   .e..............
0020 - 2e 2b 30 0d 06 09 2a 86-48 86 f7 0d 01 01 0b 05   .+0...*.H.......
0030 - 00 30 14 31 12 30 10 06-03 55 04 03 0c 09 6c 6f   .0.1.0...U....lo
0040 - 63 61 6c 68 6f 73 74 30-20 17 0d 31 37 30 31 31   calhost0 ..17011
...".......".......".......".......".......".......".......".......".....
03f0 - 11 8a cd c5 a3 0a 22 43-d5 13 f9 a5 8a 06 f9 00   ......"C........
0400 - 3c f7 86 4e e8 a5 d8 5b-92 37 f5                  <..N...[.7.
depth=0 CN = localhost
verify error:num=18:self signed certificate
verify return:1
depth=0 CN = localhost
verify return:1

read from 0x1d750b0 [0x1e6ac03] (5 bytes => 5 (0x5))
0000 - 16 03 03 00 04                                    .....

read from 0x1d750b0 [0x1e6ac08] (4 bytes => 4 (0x4))                      << SvDone
0000 - 0e                                                .
0004 - <SPACES/NULS>

write to 0x1d750b0 [0x1e74620] (395 bytes => 395 (0x18B))                 >> ClDone
0000 - 16 03 03 01 86 10 00 01-82 01 80 88 f0 87 5d b0   ..............].
0010 - ea df 3b 4d e2 35 f3 99-e6 d4 29 87 36 86 ea 30   ..;M.5....).6..0
0020 - 38 80 c7 37 66 7f 5b e7-23 38 7e 87 24 66 82 81   8..7f.[.#8~.$f..
0030 - e4 ba 6c 2a 0c 92 a8 b9-39 c1 55 16 32 88 14 cd   ..l*....9.U.2...
0040 - 95 8c 82 49 a1 c7 f9 9b-e5 8f f6 5e 7e ee 91 b3   ...I.......^~...
0050 - 2c 92 e7 a3 02 f8 9f 56-04 45 39 df a7 d6 1a 16   ,......V.E9.....
0060 - 67 5c a4 f8 87 8a c4 c8-6c 6f c6 f0 9b c9 b4 87   g\......lo......
0070 - 36 43 c1 67 9f b3 aa 11-34 b0 c2 fc 1f d9 e1 ff   6C.g....4.......
0080 - fb e1 89 db 91 58 ec cc-aa 16 19 9a 91 74 e2 46   .....X.......t.F
0090 - 22 a7 a7 f7 9e 3c 97 82-2c e4 21 b3 fa ef ba 3f   "....<..,.!....?
00a0 - 57 48 e4 b2 84 b7 c2 81-92 a9 f1 03 68 f4 e6 0c   WH..........h...
00b0 - fd 54 87 f5 e9 a0 5d e6-5f 0e bd 80 86 27 ab 0e   .T....]._....'..
00c0 - cf 92 4f bd fc 24 b9 54-72 5f 58 df 6b 2b 1d 97   ..O..$.Tr_X.k+..
00d0 - 00 60 fe 95 b0 aa d6 c7-c1 3a f9 2e 7c 92 a9 6d   .`.......:..|..m
00e0 - 28 a3 ef 3e c1 e6 2d 2d-e8 db 81 ea 51 02 3f 64   (..>..--....Q.?d
00f0 - a8 66 14 c1 4b 17 1f 55-c6 5b 3b 38 c3 6a 61 a8   .f..K..U.[;8.ja.
0100 - f7 ad 65 7d cb 14 6d b3-0f 76 19 25 8e ed bd 53   ..e}..m..v.%...S
0110 - 35 a9 a1 34 00 9d 07 81-84 51 35 e0 83 83 e3 a6   5..4.....Q5.....
0120 - c7 77 4c 61 e4 78 9c cb-f5 92 4e d6 dd c4 c2 2b   .wLa.x....N....+
0130 - 75 9e 72 a6 7f 81 6a 1c-fc 4a 51 91 81 b4 cc 33   u.r...j..JQ....3
0140 - 1c 8b 0a b6 94 8b 16 1b-86 2f 31 5e 31 e1 57 14   ........./1^1.W.
0150 - 2e b5 09 5d cf 6f ea b2-94 e9 5c cc b9 fc 24 a0   ...].o....\...$.
0160 - b7 f1 f4 9d 95 46 4f 08-5c 45 c6 2f 9f 7d 76 09   .....FO.\E./.}v.
0170 - 6a af 50 2c 89 76 82 5f-e8 34 d8 4b 84 b6 34 18   j.P,.v._.4.K..4.
0180 - 85 95 4a 3f 0f 28 88 3a-71 32 90                  ..J?.(.:q2.

write to 0x1d750b0 [0x1e74620] (6 bytes => 6 (0x6))
0000 - 14 03 03 00 01 01                                 ......           >> CHANGE_CIPHER_SPEC

write to 0x1d750b0 [0x1e74620] (53 bytes => 53 (0x35))
0000 - 16 03 03 0030  14 00000c  [ed b9 e1 33 36 0b 76   ....0.......36.v >> FINISHED (0x14) [PRF 12 bytes|SHA256_OUTSIZE 32 bytes]
0010 - c0 d1 d4 0b a3|73 ec a8-fa b5 cb 12 b6 4c 2a b1   .....s.......L*.
0020 - fb 42 7f 73 0d 06 1c 87-56 f0 db df e6 6a 25 aa   .B.s....V....j%.
0030 - fc 42 38 cb 0b]                                    .B8..

read from 0x1d750b0 [0x1e6ac03] (5 bytes => 5 (0x5))
0000 - 16 03 03 00 aa                                    .....
read from 0x1d750b0 [0x1e6ac08] (170 bytes => 170 (0xAA))
0000 - 04 00 00 a6 00 00 1c 20-00 a0 dd f4 52 01 54 8d   ....... ....R.T. << NEW_SESSION_TICKET
0010 - f8 a6 f9 2d 7d 19 20 5b-14 44 d3 2d 7b f2 ca e8   ...-}. [.D.-{...
0020 - 01 4e 94 7b fe 12 59 3a-00 2e 7e cf 74 43 7a f7   .N.{..Y:..~.tCz.
0030 - 9e cc 70 80 70 7c e3 a5-c6 9d 85 2c 36 19 4c 5c   ..p.p|.....,6.L\
0040 - ba 3b c3 e5 69 dc f3 a4-47 38 11 c9 7d 1a b0 6e   .;..i...G8..}..n
0050 - d8 49 a0 a8 e4 de 70 a8-d0 6b e4 7a b7 65 25 df   .I....p..k.z.e%.
0060 - 1b 5f 64 0f 89 69 02 72-fe eb d3 7a af 51 78 0e   ._d..i.r...z.Qx.
0070 - de 17 06 a5 f0 47 9d e0-04 d4 b1 1e be 7e ed bd   .....G.......~..
0080 - 27 8f 5d e8 ac f6 45 aa-e0 12 93 41 5f a8 4b b9   '.]...E....A_.K.
0090 - bd 43 8f a1 23 51 af 92-77 8f 38 23 3e 2e c2 f0   .C..#Q..w.8#>...
00a0 - a3 74 fa 83 94 ce 19 8a-5b 5b                     .t......[[

read from 0x1d750b0 [0x1e6ac03] (5 bytes => 5 (0x5))
0000 - 14 03 03 00 01                                    .....            << CHANGE_CIPHER_SPEC
read from 0x1d750b0 [0x1e6ac08] (1 bytes => 1 (0x1))
0000 - 01                                                .

read from 0x1d750b0 [0x1e6ac03] (5 bytes => 5 (0x5))
0000 - 16 03 03 00 30                                    ....0
read from 0x1d750b0 [0x1e6ac08] (48 bytes => 48 (0x30))
0000 - 14 00000c  [06 86 0d 5c-92 0b 63 04 cc b4 f0 00   .......\..c..... << FINISHED (0x14) [PRF 12 bytes|SHA256_OUTSIZE 32 bytes]
0010 -|49 d6 dd 56 73 e3 d2 e8-22 d6 bd 61 b2 b3 af f0   I..Vs..."..a....
0020 - f5 00 8a 80 82 04 33 a7-50 8e ae 3b 4c 8c cf 4a]  ......3.P..;L..J
---
Certificate chain
 0 s:/CN=localhost
   i:/CN=localhost
---
Server certificate
-----BEGIN CERTIFICATE-----
...".......".......".......".......".......".......".......".......".....
-----END CERTIFICATE-----
subject=/CN=localhost
issuer=/CN=localhost
---
No client certificate CA names sent
---
SSL handshake has read 1346 bytes and written 553 bytes
---
New, TLSv1/SSLv3, Cipher is NULL-SHA256
Server public key is 3072 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
    Protocol  : TLSv1.2
    Cipher    : NULL-SHA256
    Session-ID: 5D62B36950F3DEB571707CD1B815E9E275041B9DB70D7F3E25C4A6535B13B616
    Session-ID-ctx:
    Master-Key: 4D08108C59417E0A41656636C51BA5B83F4EFFF9F4C860987B47B31250E5D1816D00940DBCCC196C2D99C8462C889DF1
    Key-Arg   : None
    Krb5 Principal: None
    PSK identity: None
    PSK identity hint: None
    TLS session ticket lifetime hint: 7200 (seconds)
    TLS session ticket:
    0000 - dd f4 52 01 54 8d f8 a6-f9 2d 7d 19 20 5b 14 44   ..R.T....-}. [.D
    0010 - d3 2d 7b f2 ca e8 01 4e-94 7b fe 12 59 3a 00 2e   .-{....N.{..Y:..
    0020 - 7e cf 74 43 7a f7 9e cc-70 80 70 7c e3 a5 c6 9d   ~.tCz...p.p|....
    0030 - 85 2c 36 19 4c 5c ba 3b-c3 e5 69 dc f3 a4 47 38   .,6.L\.;..i...G8
    0040 - 11 c9 7d 1a b0 6e d8 49-a0 a8 e4 de 70 a8 d0 6b   ..}..n.I....p..k
    0050 - e4 7a b7 65 25 df 1b 5f-64 0f 89 69 02 72 fe eb   .z.e%.._d..i.r..
    0060 - d3 7a af 51 78 0e de 17-06 a5 f0 47 9d e0 04 d4   .z.Qx......G....
    0070 - b1 1e be 7e ed bd 27 8f-5d e8 ac f6 45 aa e0 12   ...~..'.]...E...
    0080 - 93 41 5f a8 4b b9 bd 43-8f a1 23 51 af 92 77 8f   .A_.K..C..#Q..w.
    0090 - 38 23 3e 2e c2 f0 a3 74-fa 83 94 ce 19 8a 5b 5b   8#>....t......[[

    Start Time: 1484574330
    Timeout   : 7200 (sec)
    Verify return code: 18 (self signed certificate)
---
read from 0x1d750b0 [0x1e6ac03] (5 bytes => 5 (0x5))
0000 - 17 03 03 00 21                                    ....!
read from 0x1d750b0 [0x1e6ac08] (33 bytes => 33 (0x21))
0000 - 0a 74 5b 50 02 13 75 a4-27 0a 40 b1 53 74 52 14   .t[P..u.'.@.StR.
0010 - e7 1e 6a 6c c1 60 2e 93-7e a5 d9 43 1d 8e f6 08   ..jl.`..~..C....
0020 - 69                                                i

read from 0x1d750b0 [0x1e6ac03] (5 bytes => 5 (0x5))
0000 - 17 03 03 00 21                                    ....!
read from 0x1d750b0 [0x1e6ac08] (33 bytes => 33 (0x21))
0000 - 0a 1b ce 44 98 4f 81 c5-28 7a cc 79 62 db d2 86   ...D.O..(z.yb...
0010 - 6a 55 a4 c7 73 49 ef 3e-bd 03 99 76 df 65 2a a1   jU..sI.>...v.e*.
0020 - b6                                                .

read from 0x1d750b0 [0x1e6ac03] (5 bytes => 5 (0x5))
0000 - 17 03 03 00 21                                    ....!
read from 0x1d750b0 [0x1e6ac08] (33 bytes => 33 (0x21))
0000 - 0a 67 66 34 ba 68 36 3c-ad 0a c1 f5 c0 5a 50 fe   .gf4.h6<.....ZP.
0010 - 68 cd 04 65 e9 de 6e 98-f9 e2 41 1e 0b 9b 84 06   h..e..n...A.....
0020 - 64                                                d
*/