2 * Copyright (C) 2017 Denys Vlasenko
4 * Licensed under GPLv2, see file LICENSE in this source tree.
7 //config: bool #No description makes it a hidden option
10 //kbuild:lib-$(CONFIG_TLS) += tls.o
11 //kbuild:lib-$(CONFIG_TLS) += tls_pstm.o
12 //kbuild:lib-$(CONFIG_TLS) += tls_pstm_montgomery_reduce.o
13 //kbuild:lib-$(CONFIG_TLS) += tls_pstm_mul_comba.o
14 //kbuild:lib-$(CONFIG_TLS) += tls_pstm_sqr_comba.o
15 //kbuild:lib-$(CONFIG_TLS) += tls_rsa.o
16 //kbuild:lib-$(CONFIG_TLS) += tls_aes.o
17 ////kbuild:lib-$(CONFIG_TLS) += tls_aes_gcm.o
21 //Tested against kernel.org:
25 //#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA // ok, recvs SERVER_KEY_EXCHANGE *** matrixssl uses this on my box
26 //#define CIPHER_ID TLS_RSA_WITH_AES_256_CBC_SHA256 // ok, no SERVER_KEY_EXCHANGE
27 //#define CIPHER_ID TLS_DH_anon_WITH_AES_256_CBC_SHA // SSL_ALERT_HANDSHAKE_FAILURE
28 //^^^^^^^^^^^^^^^^^^^^^^^ (tested b/c this one doesn't req server certs... no luck, server refuses it)
29 //#define CIPHER_ID TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 // SSL_ALERT_HANDSHAKE_FAILURE
30 //#define CIPHER_ID TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
31 //#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 // ok, recvs SERVER_KEY_EXCHANGE
32 //#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
33 //#define CIPHER_ID TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384
34 //#define CIPHER_ID TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
35 //#define CIPHER_ID TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384
36 //#define CIPHER_ID TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
37 //#define CIPHER_ID TLS_RSA_WITH_AES_256_GCM_SHA384 // ok, no SERVER_KEY_EXCHANGE
38 //#define CIPHER_ID TLS_RSA_WITH_AES_128_GCM_SHA256 // ok, no SERVER_KEY_EXCHANGE *** select this?
40 // works against "openssl s_server -cipher NULL"
41 // and against wolfssl-3.9.10-stable/examples/server/server.c:
42 //#define CIPHER_ID1 TLS_RSA_WITH_NULL_SHA256 // for testing (does everything except encrypting)
44 // works against wolfssl-3.9.10-stable/examples/server/server.c
45 // works for kernel.org
46 // does not work for cdn.kernel.org (e.g. downloading an actual tarball, not a web page)
47 // getting alert 40 "handshake failure" at once
48 // with GNU Wget 1.18, they agree on TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (0xC02F) cipher
49 // fail: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES256-SHA256
50 // fail: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES256-GCM-SHA384
51 // fail: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES128-SHA256
52 // ok: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES128-GCM-SHA256
53 // ok: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher AES128-SHA
54 // (TLS_RSA_WITH_AES_128_CBC_SHA - in TLS 1.2 it's mandated to be always supported)
55 #define CIPHER_ID1 TLS_RSA_WITH_AES_256_CBC_SHA256 // no SERVER_KEY_EXCHANGE from peer
56 // Works with "wget https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.9.5.tar.xz"
57 #define CIPHER_ID2 TLS_RSA_WITH_AES_128_CBC_SHA
61 #define TLS_DEBUG_HASH 0
62 #define TLS_DEBUG_DER 0
63 #define TLS_DEBUG_FIXED_SECRETS 0
65 # define dump_raw_out(...) dump_hex(__VA_ARGS__)
67 # define dump_raw_out(...) ((void)0)
70 # define dump_raw_in(...) dump_hex(__VA_ARGS__)
72 # define dump_raw_in(...) ((void)0)
76 # define dbg(...) fprintf(stderr, __VA_ARGS__)
78 # define dbg(...) ((void)0)
82 # define dbg_der(...) fprintf(stderr, __VA_ARGS__)
84 # define dbg_der(...) ((void)0)
87 #define RECORD_TYPE_CHANGE_CIPHER_SPEC 20
88 #define RECORD_TYPE_ALERT 21
89 #define RECORD_TYPE_HANDSHAKE 22
90 #define RECORD_TYPE_APPLICATION_DATA 23
92 #define HANDSHAKE_HELLO_REQUEST 0
93 #define HANDSHAKE_CLIENT_HELLO 1
94 #define HANDSHAKE_SERVER_HELLO 2
95 #define HANDSHAKE_HELLO_VERIFY_REQUEST 3
96 #define HANDSHAKE_NEW_SESSION_TICKET 4
97 #define HANDSHAKE_CERTIFICATE 11
98 #define HANDSHAKE_SERVER_KEY_EXCHANGE 12
99 #define HANDSHAKE_CERTIFICATE_REQUEST 13
100 #define HANDSHAKE_SERVER_HELLO_DONE 14
101 #define HANDSHAKE_CERTIFICATE_VERIFY 15
102 #define HANDSHAKE_CLIENT_KEY_EXCHANGE 16
103 #define HANDSHAKE_FINISHED 20
105 #define SSL_NULL_WITH_NULL_NULL 0x0000
106 #define SSL_RSA_WITH_NULL_MD5 0x0001
107 #define SSL_RSA_WITH_NULL_SHA 0x0002
108 #define SSL_RSA_WITH_RC4_128_MD5 0x0004
109 #define SSL_RSA_WITH_RC4_128_SHA 0x0005
110 #define SSL_RSA_WITH_3DES_EDE_CBC_SHA 0x000A /* 10 */
111 #define TLS_RSA_WITH_AES_128_CBC_SHA 0x002F /* 47 */
112 #define TLS_RSA_WITH_AES_256_CBC_SHA 0x0035 /* 53 */
113 #define TLS_RSA_WITH_NULL_SHA256 0x003B /* 59 */
115 #define TLS_EMPTY_RENEGOTIATION_INFO_SCSV 0x00FF
117 #define TLS_RSA_WITH_IDEA_CBC_SHA 0x0007 /* 7 */
118 #define SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA 0x0016 /* 22 */
119 #define SSL_DH_anon_WITH_RC4_128_MD5 0x0018 /* 24 */
120 #define SSL_DH_anon_WITH_3DES_EDE_CBC_SHA 0x001B /* 27 */
121 #define TLS_DHE_RSA_WITH_AES_128_CBC_SHA 0x0033 /* 51 */
122 #define TLS_DHE_RSA_WITH_AES_256_CBC_SHA 0x0039 /* 57 */
123 #define TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 0x0067 /* 103 */
124 #define TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 0x006B /* 107 */
125 #define TLS_DH_anon_WITH_AES_128_CBC_SHA 0x0034 /* 52 */
126 #define TLS_DH_anon_WITH_AES_256_CBC_SHA 0x003A /* 58 */
127 #define TLS_RSA_WITH_AES_128_CBC_SHA256 0x003C /* 60 */
128 #define TLS_RSA_WITH_AES_256_CBC_SHA256 0x003D /* 61 */
129 #define TLS_RSA_WITH_SEED_CBC_SHA 0x0096 /* 150 */
130 #define TLS_PSK_WITH_AES_128_CBC_SHA 0x008C /* 140 */
131 #define TLS_PSK_WITH_AES_128_CBC_SHA256 0x00AE /* 174 */
132 #define TLS_PSK_WITH_AES_256_CBC_SHA384 0x00AF /* 175 */
133 #define TLS_PSK_WITH_AES_256_CBC_SHA 0x008D /* 141 */
134 #define TLS_DHE_PSK_WITH_AES_128_CBC_SHA 0x0090 /* 144 */
135 #define TLS_DHE_PSK_WITH_AES_256_CBC_SHA 0x0091 /* 145 */
136 #define TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA 0xC004 /* 49156 */
137 #define TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA 0xC005 /* 49157 */
138 #define TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA 0xC009 /* 49161 */
139 #define TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA 0xC00A /* 49162 */
140 #define TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA 0xC012 /* 49170 */
141 #define TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA 0xC013 /* 49171 */
142 #define TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA 0xC014 /* 49172 */
143 #define TLS_ECDH_RSA_WITH_AES_128_CBC_SHA 0xC00E /* 49166 */
144 #define TLS_ECDH_RSA_WITH_AES_256_CBC_SHA 0xC00F /* 49167 */
145 #define TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 0xC023 /* 49187 */
146 #define TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 0xC024 /* 49188 */
147 #define TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 0xC025 /* 49189 */
148 #define TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 0xC026 /* 49190 */
149 #define TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 0xC027 /* 49191 */
150 #define TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 0xC028 /* 49192 */
151 #define TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 0xC029 /* 49193 */
152 #define TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 0xC02A /* 49194 */
154 /* RFC 5288 "AES Galois Counter Mode (GCM) Cipher Suites for TLS" */
155 #define TLS_RSA_WITH_AES_128_GCM_SHA256 0x009C /* 156 */
156 #define TLS_RSA_WITH_AES_256_GCM_SHA384 0x009D /* 157 */
157 #define TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 0xC02B /* 49195 */
158 #define TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 0xC02C /* 49196 */
159 #define TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 0xC02D /* 49197 */
160 #define TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 0xC02E /* 49198 */
161 #define TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 0xC02F /* 49199 */
162 #define TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 0xC030 /* 49200 */
163 #define TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 0xC031 /* 49201 */
164 #define TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 0xC032 /* 49202 */
166 /* Might go to libbb.h */
167 #define TLS_MAX_CRYPTBLOCK_SIZE 16
168 #define TLS_MAX_OUTBUF (1 << 14)
179 RSA_PREMASTER_SIZE = 48,
183 /* 8 = 3+5. 3 extra bytes result in record data being 32-bit aligned */
184 OUTBUF_PFX = 8 + AES_BLOCKSIZE, /* header + IV */
185 OUTBUF_SFX = TLS_MAX_MAC_SIZE + TLS_MAX_CRYPTBLOCK_SIZE, /* MAC + padding */
188 // | 6.2.1. Fragmentation
189 // | The record layer fragments information blocks into TLSPlaintext
190 // | records carrying data in chunks of 2^14 bytes or less. Client
191 // | message boundaries are not preserved in the record layer (i.e.,
192 // | multiple client messages of the same ContentType MAY be coalesced
193 // | into a single TLSPlaintext record, or a single message MAY be
194 // | fragmented across several records)
197 // | The length (in bytes) of the following TLSPlaintext.fragment.
198 // | The length MUST NOT exceed 2^14.
200 // | 6.2.2. Record Compression and Decompression
202 // | Compression must be lossless and may not increase the content length
203 // | by more than 1024 bytes. If the decompression function encounters a
204 // | TLSCompressed.fragment that would decompress to a length in excess of
205 // | 2^14 bytes, it MUST report a fatal decompression failure error.
208 // | The length (in bytes) of the following TLSCompressed.fragment.
209 // | The length MUST NOT exceed 2^14 + 1024.
211 // | 6.2.3. Record Payload Protection
212 // | The encryption and MAC functions translate a TLSCompressed
213 // | structure into a TLSCiphertext. The decryption functions reverse
214 // | the process. The MAC of the record also includes a sequence
215 // | number so that missing, extra, or repeated messages are
219 // | The length (in bytes) of the following TLSCiphertext.fragment.
220 // | The length MUST NOT exceed 2^14 + 2048.
221 MAX_INBUF = RECHDR_LEN + (1 << 14) + 2048,
226 uint8_t proto_maj, proto_min;
227 uint8_t len16_hi, len16_lo;
230 struct tls_handshake_data {
231 /* In bbox, md5/sha1/sha256 ctx's are the same structure */
232 md5sha_ctx_t handshake_hash_ctx;
234 uint8_t client_and_server_rand32[2 * 32];
235 uint8_t master_secret[48];
236 //TODO: store just the DER key here, parse/use/delete it when sending client key
237 //this way it will stay key type agnostic here.
238 psRsaKey_t server_rsa_pub_key;
240 unsigned saved_client_hello_size;
241 uint8_t saved_client_hello[1];
245 static unsigned get24be(const uint8_t *p)
247 return 0x100*(0x100*p[0] + p[1]) + p[2];
251 static void dump_hex(const char *fmt, const void *vp, int len)
253 char hexbuf[32 * 1024 + 4];
254 const uint8_t *p = vp;
256 bin2hex(hexbuf, (void*)p, len)[0] = '\0';
260 static void dump_tls_record(const void *vp, int len)
262 const uint8_t *p = vp;
266 if (len < RECHDR_LEN) {
267 dump_hex("< |%s|\n", p, len);
270 xhdr_len = 0x100*p[3] + p[4];
271 dbg("< hdr_type:%u ver:%u.%u len:%u", p[0], p[1], p[2], xhdr_len);
274 if (len >= 4 && p[-RECHDR_LEN] == RECORD_TYPE_HANDSHAKE) {
275 unsigned len24 = get24be(p + 1);
276 dbg(" type:%u len24:%u", p[0], len24);
280 dump_hex(" |%s|\n", p, xhdr_len);
286 # define dump_hex(...) ((void)0)
287 # define dump_tls_record(...) ((void)0)
290 void tls_get_random(void *buf, unsigned len)
292 if (len != open_read_close("/dev/urandom", buf, len))
296 /* Nondestructively see the current hash value */
297 static unsigned sha_peek(md5sha_ctx_t *ctx, void *buffer)
299 md5sha_ctx_t ctx_copy = *ctx; /* struct copy */
300 return sha_end(&ctx_copy, buffer);
303 static ALWAYS_INLINE unsigned get_handshake_hash(tls_state_t *tls, void *buffer)
305 return sha_peek(&tls->hsd->handshake_hash_ctx, buffer);
309 # define hash_handshake(tls, fmt, buffer, len) \
310 hash_handshake(tls, buffer, len)
312 static void hash_handshake(tls_state_t *tls, const char *fmt, const void *buffer, unsigned len)
314 md5sha_hash(&tls->hsd->handshake_hash_ctx, buffer, len);
317 uint8_t h[TLS_MAX_MAC_SIZE];
318 dump_hex(fmt, buffer, len);
319 dbg(" (%u bytes) ", (int)len);
320 len = sha_peek(&tls->hsd->handshake_hash_ctx, h);
321 if (len == SHA1_OUTSIZE)
322 dump_hex("sha1:%s\n", h, len);
324 if (len == SHA256_OUTSIZE)
325 dump_hex("sha256:%s\n", h, len);
327 dump_hex("sha???:%s\n", h, len);
333 // HMAC(key, text) based on a hash H (say, sha256) is:
334 // ipad = [0x36 x INSIZE]
335 // opad = [0x5c x INSIZE]
336 // HMAC(key, text) = H((key XOR opad) + H((key XOR ipad) + text))
338 // H(key XOR opad) and H(key XOR ipad) can be precomputed
339 // if we often need HMAC hmac with the same key.
341 // text is often given in disjoint pieces.
342 typedef struct hmac_precomputed {
343 md5sha_ctx_t hashed_key_xor_ipad;
344 md5sha_ctx_t hashed_key_xor_opad;
345 } hmac_precomputed_t;
347 static unsigned hmac_sha_precomputed_v(
348 hmac_precomputed_t *pre,
355 /* pre->hashed_key_xor_ipad contains unclosed "H((key XOR ipad) +" state */
356 /* pre->hashed_key_xor_opad contains unclosed "H((key XOR opad) +" state */
358 /* calculate out = H((key XOR ipad) + text) */
359 while ((text = va_arg(va, uint8_t*)) != NULL) {
360 unsigned text_size = va_arg(va, unsigned);
361 md5sha_hash(&pre->hashed_key_xor_ipad, text, text_size);
363 len = sha_end(&pre->hashed_key_xor_ipad, out);
365 /* out = H((key XOR opad) + out) */
366 md5sha_hash(&pre->hashed_key_xor_opad, out, len);
367 return sha_end(&pre->hashed_key_xor_opad, out);
370 typedef void md5sha_begin_func(md5sha_ctx_t *ctx) FAST_FUNC;
371 static void hmac_begin(hmac_precomputed_t *pre, uint8_t *key, unsigned key_size, md5sha_begin_func *begin)
373 uint8_t key_xor_ipad[SHA_INSIZE];
374 uint8_t key_xor_opad[SHA_INSIZE];
375 uint8_t tempkey[SHA1_OUTSIZE < SHA256_OUTSIZE ? SHA256_OUTSIZE : SHA1_OUTSIZE];
378 // "The authentication key can be of any length up to INSIZE, the
379 // block length of the hash function. Applications that use keys longer
380 // than INSIZE bytes will first hash the key using H and then use the
381 // resultant OUTSIZE byte string as the actual key to HMAC."
382 if (key_size > SHA_INSIZE) {
385 md5sha_hash(&ctx, key, key_size);
386 key_size = sha_end(&ctx, tempkey);
389 for (i = 0; i < key_size; i++) {
390 key_xor_ipad[i] = key[i] ^ 0x36;
391 key_xor_opad[i] = key[i] ^ 0x5c;
393 for (; i < SHA_INSIZE; i++) {
394 key_xor_ipad[i] = 0x36;
395 key_xor_opad[i] = 0x5c;
398 begin(&pre->hashed_key_xor_ipad);
399 begin(&pre->hashed_key_xor_opad);
400 md5sha_hash(&pre->hashed_key_xor_ipad, key_xor_ipad, SHA_INSIZE);
401 md5sha_hash(&pre->hashed_key_xor_opad, key_xor_opad, SHA_INSIZE);
404 static unsigned hmac(tls_state_t *tls, uint8_t *out, uint8_t *key, unsigned key_size, ...)
406 hmac_precomputed_t pre;
410 va_start(va, key_size);
412 hmac_begin(&pre, key, key_size,
413 (tls->MAC_size == SHA256_OUTSIZE)
417 len = hmac_sha_precomputed_v(&pre, out, va);
423 static unsigned hmac_sha256(/*tls_state_t *tls,*/ uint8_t *out, uint8_t *key, unsigned key_size, ...)
425 hmac_precomputed_t pre;
429 va_start(va, key_size);
431 hmac_begin(&pre, key, key_size, sha256_begin);
432 len = hmac_sha_precomputed_v(&pre, out, va);
439 // 5. HMAC and the Pseudorandom Function
441 // In this section, we define one PRF, based on HMAC. This PRF with the
442 // SHA-256 hash function is used for all cipher suites defined in this
443 // document and in TLS documents published prior to this document when
444 // TLS 1.2 is negotiated.
445 // ^^^^^^^^^^^^^ IMPORTANT!
446 // PRF uses sha256 regardless of cipher (at least for all ciphers
447 // defined by RFC5246). It's not sha1 for AES_128_CBC_SHA!
449 // P_hash(secret, seed) = HMAC_hash(secret, A(1) + seed) +
450 // HMAC_hash(secret, A(2) + seed) +
451 // HMAC_hash(secret, A(3) + seed) + ...
452 // where + indicates concatenation.
453 // A() is defined as:
455 // A(1) = HMAC_hash(secret, A(0)) = HMAC_hash(secret, seed)
456 // A(i) = HMAC_hash(secret, A(i-1))
457 // P_hash can be iterated as many times as necessary to produce the
458 // required quantity of data. For example, if P_SHA256 is being used to
459 // create 80 bytes of data, it will have to be iterated three times
460 // (through A(3)), creating 96 bytes of output data; the last 16 bytes
461 // of the final iteration will then be discarded, leaving 80 bytes of
464 // TLS's PRF is created by applying P_hash to the secret as:
466 // PRF(secret, label, seed) = P_<hash>(secret, label + seed)
468 // The label is an ASCII string.
469 static void prf_hmac_sha256(/*tls_state_t *tls,*/
470 uint8_t *outbuf, unsigned outbuf_size,
471 uint8_t *secret, unsigned secret_size,
473 uint8_t *seed, unsigned seed_size)
475 uint8_t a[TLS_MAX_MAC_SIZE];
476 uint8_t *out_p = outbuf;
477 unsigned label_size = strlen(label);
478 unsigned MAC_size = SHA256_OUTSIZE;
480 /* In P_hash() calculation, "seed" is "label + seed": */
481 #define SEED label, label_size, seed, seed_size
482 #define SECRET secret, secret_size
483 #define A a, MAC_size
485 /* A(1) = HMAC_hash(secret, seed) */
486 hmac_sha256(/*tls,*/ a, SECRET, SEED, NULL);
487 //TODO: convert hmac to precomputed
490 /* HMAC_hash(secret, A(1) + seed) */
491 if (outbuf_size <= MAC_size) {
492 /* Last, possibly incomplete, block */
493 /* (use a[] as temp buffer) */
494 hmac_sha256(/*tls,*/ a, SECRET, A, SEED, NULL);
495 memcpy(out_p, a, outbuf_size);
498 /* Not last block. Store directly to result buffer */
499 hmac_sha256(/*tls,*/ out_p, SECRET, A, SEED, NULL);
501 outbuf_size -= MAC_size;
502 /* A(2) = HMAC_hash(secret, A(1)) */
503 hmac_sha256(/*tls,*/ a, SECRET, A, NULL);
510 static void bad_record_die(tls_state_t *tls, const char *expected, int len)
512 bb_error_msg("got bad TLS record (len:%d) while expecting %s", len, expected);
514 uint8_t *p = tls->inbuf;
516 fprintf(stderr, " %02x", *p++);
524 static void tls_error_die(tls_state_t *tls, int line)
526 dump_tls_record(tls->inbuf, tls->ofs_to_buffered + tls->buffered_size);
527 bb_error_msg_and_die("tls error at line %d cipher:%04x", line, tls->cipher_id);
529 #define tls_error_die(tls) tls_error_die(tls, __LINE__)
532 static void tls_free_inbuf(tls_state_t *tls)
534 if (tls->buffered_size == 0) {
542 static void tls_free_outbuf(tls_state_t *tls)
545 tls->outbuf_size = 0;
549 static void *tls_get_outbuf(tls_state_t *tls, int len)
551 if (len > TLS_MAX_OUTBUF)
553 len += OUTBUF_PFX + OUTBUF_SFX;
554 if (tls->outbuf_size < len) {
555 tls->outbuf_size = len;
556 tls->outbuf = xrealloc(tls->outbuf, len);
558 return tls->outbuf + OUTBUF_PFX;
561 static void xwrite_encrypted(tls_state_t *tls, unsigned size, unsigned type)
563 uint8_t *buf = tls->outbuf + OUTBUF_PFX;
564 struct record_hdr *xhdr;
565 uint8_t padding_length;
567 xhdr = (void*)(buf - RECHDR_LEN);
568 if (CIPHER_ID1 != TLS_RSA_WITH_NULL_SHA256 /* if "no encryption" can't be selected */
569 || tls->cipher_id != TLS_RSA_WITH_NULL_SHA256 /* or if it wasn't selected */
571 xhdr = (void*)(buf - RECHDR_LEN - AES_BLOCKSIZE); /* place for IV */
575 xhdr->proto_maj = TLS_MAJ;
576 xhdr->proto_min = TLS_MIN;
577 /* fake unencrypted record len for MAC calculation */
578 xhdr->len16_hi = size >> 8;
579 xhdr->len16_lo = size & 0xff;
581 /* Calculate MAC signature */
582 hmac(tls, buf + size, /* result */
583 tls->client_write_MAC_key, tls->MAC_size,
584 &tls->write_seq64_be, sizeof(tls->write_seq64_be),
589 tls->write_seq64_be = SWAP_BE64(1 + SWAP_BE64(tls->write_seq64_be));
591 size += tls->MAC_size;
594 // 6.2.3.1. Null or Standard Stream Cipher
596 // Stream ciphers (including BulkCipherAlgorithm.null; see Appendix A.6)
597 // convert TLSCompressed.fragment structures to and from stream
598 // TLSCiphertext.fragment structures.
600 // stream-ciphered struct {
601 // opaque content[TLSCompressed.length];
602 // opaque MAC[SecurityParameters.mac_length];
603 // } GenericStreamCipher;
605 // The MAC is generated as:
606 // MAC(MAC_write_key, seq_num +
607 // TLSCompressed.type +
608 // TLSCompressed.version +
609 // TLSCompressed.length +
610 // TLSCompressed.fragment);
611 // where "+" denotes concatenation.
613 // The sequence number for this record.
615 // The MAC algorithm specified by SecurityParameters.mac_algorithm.
617 // Note that the MAC is computed before encryption. The stream cipher
618 // encrypts the entire block, including the MAC.
620 // Appendix C. Cipher Suite Definitions
622 // MAC Algorithm mac_length mac_key_length
623 // -------- ----------- ---------- --------------
624 // SHA HMAC-SHA1 20 20
625 // SHA256 HMAC-SHA256 32 32
626 if (CIPHER_ID1 == TLS_RSA_WITH_NULL_SHA256
627 && tls->cipher_id == TLS_RSA_WITH_NULL_SHA256
629 /* No encryption, only signing */
630 xhdr->len16_hi = size >> 8;
631 xhdr->len16_lo = size & 0xff;
632 dump_raw_out(">> %s\n", xhdr, RECHDR_LEN + size);
633 xwrite(tls->ofd, xhdr, RECHDR_LEN + size);
634 dbg("wrote %u bytes (NULL crypt, SHA256 hash)\n", size);
638 // 6.2.3.2. CBC Block Cipher
639 // For block ciphers (such as 3DES or AES), the encryption and MAC
640 // functions convert TLSCompressed.fragment structures to and from block
641 // TLSCiphertext.fragment structures.
643 // opaque IV[SecurityParameters.record_iv_length];
644 // block-ciphered struct {
645 // opaque content[TLSCompressed.length];
646 // opaque MAC[SecurityParameters.mac_length];
647 // uint8 padding[GenericBlockCipher.padding_length];
648 // uint8 padding_length;
650 // } GenericBlockCipher;
653 // The Initialization Vector (IV) SHOULD be chosen at random, and
654 // MUST be unpredictable. Note that in versions of TLS prior to 1.1,
655 // there was no IV field (...). For block ciphers, the IV length is
656 // of length SecurityParameters.record_iv_length, which is equal to the
657 // SecurityParameters.block_size.
659 // Padding that is added to force the length of the plaintext to be
660 // an integral multiple of the block cipher's block length.
662 // The padding length MUST be such that the total size of the
663 // GenericBlockCipher structure is a multiple of the cipher's block
664 // length. Legal values range from zero to 255, inclusive.
666 // Appendix C. Cipher Suite Definitions
669 // Cipher Type Material Size Size
670 // ------------ ------ -------- ---- -----
671 // AES_128_CBC Block 16 16 16
672 // AES_256_CBC Block 32 16 16
674 /* Fill IV and padding in outbuf */
675 tls_get_random(buf - AES_BLOCKSIZE, AES_BLOCKSIZE); /* IV */
676 dbg("before crypt: 5 hdr + %u data + %u hash bytes\n", size, tls->MAC_size);
677 // RFC is talking nonsense:
678 // "Padding that is added to force the length of the plaintext to be
679 // an integral multiple of the block cipher's block length."
680 // WRONG. _padding+padding_length_, not just _padding_,
682 // IOW: padding_length is the last byte of padding[] array,
683 // contrary to what RFC depicts.
685 // What actually happens is that there is always padding.
686 // If you need one byte to reach BLOCKSIZE, this byte is 0x00.
687 // If you need two bytes, they are both 0x01.
688 // If you need three, they are 0x02,0x02,0x02. And so on.
689 // If you need no bytes to reach BLOCKSIZE, you have to pad a full
690 // BLOCKSIZE with bytes of value (BLOCKSIZE-1).
691 // It's ok to have more than minimum padding, but we do minimum.
692 padding_length = (~size) & (AES_BLOCKSIZE - 1);
694 buf[size++] = padding_length; /* padding */
695 } while ((size & (AES_BLOCKSIZE - 1)) != 0);
697 /* Encrypt content+MAC+padding in place */
699 tls->client_write_key, tls->key_size, /* selects 128/256 */
700 buf - AES_BLOCKSIZE, /* IV */
701 buf, size, /* plaintext */
706 dbg("writing 5 + %u IV + %u encrypted bytes, padding_length:0x%02x\n",
707 AES_BLOCKSIZE, size, padding_length);
708 size += AES_BLOCKSIZE; /* + IV */
709 xhdr->len16_hi = size >> 8;
710 xhdr->len16_lo = size & 0xff;
711 dump_raw_out(">> %s\n", xhdr, RECHDR_LEN + size);
712 xwrite(tls->ofd, xhdr, RECHDR_LEN + size);
713 dbg("wrote %u bytes\n", (int)RECHDR_LEN + size);
716 static void xwrite_handshake_record(tls_state_t *tls, unsigned size)
718 //if (!tls->encrypt_on_write) {
719 uint8_t *buf = tls->outbuf + OUTBUF_PFX;
720 struct record_hdr *xhdr = (void*)(buf - RECHDR_LEN);
722 xhdr->type = RECORD_TYPE_HANDSHAKE;
723 xhdr->proto_maj = TLS_MAJ;
724 xhdr->proto_min = TLS_MIN;
725 xhdr->len16_hi = size >> 8;
726 xhdr->len16_lo = size & 0xff;
727 dump_raw_out(">> %s\n", xhdr, RECHDR_LEN + size);
728 xwrite(tls->ofd, xhdr, RECHDR_LEN + size);
729 dbg("wrote %u bytes\n", (int)RECHDR_LEN + size);
732 //xwrite_encrypted(tls, size, RECORD_TYPE_HANDSHAKE);
735 static void xwrite_and_update_handshake_hash(tls_state_t *tls, unsigned size)
737 if (!tls->encrypt_on_write) {
740 xwrite_handshake_record(tls, size);
741 /* Handshake hash does not include record headers */
742 buf = tls->outbuf + OUTBUF_PFX;
743 hash_handshake(tls, ">> hash:%s", buf, size);
746 xwrite_encrypted(tls, size, RECORD_TYPE_HANDSHAKE);
749 static int tls_has_buffered_record(tls_state_t *tls)
751 int buffered = tls->buffered_size;
752 struct record_hdr *xhdr;
755 if (buffered < RECHDR_LEN)
757 xhdr = (void*)(tls->inbuf + tls->ofs_to_buffered);
758 rec_size = RECHDR_LEN + (0x100 * xhdr->len16_hi + xhdr->len16_lo);
759 if (buffered < rec_size)
764 static const char *alert_text(int code)
767 case 20: return "bad MAC";
768 case 50: return "decode error";
769 case 51: return "decrypt error";
770 case 40: return "handshake failure";
771 case 112: return "unrecognized name";
776 static int tls_xread_record(tls_state_t *tls)
778 struct record_hdr *xhdr;
784 dbg("ofs_to_buffered:%u buffered_size:%u\n", tls->ofs_to_buffered, tls->buffered_size);
785 total = tls->buffered_size;
787 memmove(tls->inbuf, tls->inbuf + tls->ofs_to_buffered, total);
788 //dbg("<< remaining at %d [%d] ", tls->ofs_to_buffered, total);
789 //dump_raw_in("<< %s\n", tls->inbuf, total);
796 if (total >= RECHDR_LEN && target == MAX_INBUF) {
797 xhdr = (void*)tls->inbuf;
798 target = RECHDR_LEN + (0x100 * xhdr->len16_hi + xhdr->len16_lo);
799 if (target > MAX_INBUF) {
800 /* malformed input (too long): yell and die */
801 tls->buffered_size = 0;
802 tls->ofs_to_buffered = total;
805 /* can also check type/proto_maj/proto_min here */
806 dbg("xhdr type:%d ver:%d.%d len:%d\n",
807 xhdr->type, xhdr->proto_maj, xhdr->proto_min,
808 0x100 * xhdr->len16_hi + xhdr->len16_lo
811 /* if total >= target, we have a full packet (and possibly more)... */
812 if (total - target >= 0)
814 /* input buffer is grown only as needed */
815 rem = tls->inbuf_size - total;
817 tls->inbuf_size += MAX_INBUF / 8;
818 if (tls->inbuf_size > MAX_INBUF)
819 tls->inbuf_size = MAX_INBUF;
820 dbg("inbuf_size:%d\n", tls->inbuf_size);
821 rem = tls->inbuf_size - total;
822 tls->inbuf = xrealloc(tls->inbuf, tls->inbuf_size);
824 sz = safe_read(tls->ifd, tls->inbuf + total, rem);
826 if (sz == 0 && total == 0) {
827 /* "Abrupt" EOF, no TLS shutdown (seen from kernel.org) */
828 dbg("EOF (without TLS shutdown) from peer\n");
829 tls->buffered_size = 0;
832 bb_perror_msg_and_die("short read, have only %d", total);
834 dump_raw_in("<< %s\n", tls->inbuf + total, sz);
837 tls->buffered_size = total - target;
838 tls->ofs_to_buffered = target;
839 //dbg("<< stashing at %d [%d] ", tls->ofs_to_buffered, tls->buffered_size);
840 //dump_hex("<< %s\n", tls->inbuf + tls->ofs_to_buffered, tls->buffered_size);
842 sz = target - RECHDR_LEN;
844 /* Needs to be decrypted? */
845 if (tls->min_encrypted_len_on_read > tls->MAC_size) {
846 uint8_t *p = tls->inbuf + RECHDR_LEN;
849 if (sz & (AES_BLOCKSIZE-1)
850 || sz < (int)tls->min_encrypted_len_on_read
852 bb_error_msg_and_die("bad encrypted len:%u < %u",
853 sz, tls->min_encrypted_len_on_read);
855 /* Decrypt content+MAC+padding, moving it over IV in the process */
856 sz -= AES_BLOCKSIZE; /* we will overwrite IV now */
858 tls->server_write_key, tls->key_size, /* selects 128/256 */
860 p + AES_BLOCKSIZE, sz, /* ciphertext */
863 padding_len = p[sz - 1];
864 dbg("encrypted size:%u type:0x%02x padding_length:0x%02x\n", sz, p[0], padding_len);
866 sz -= tls->MAC_size + padding_len; /* drop MAC and padding */
868 // bb_error_msg_and_die("bad padding size:%u", padding_len);
870 /* if nonzero, then it's TLS_RSA_WITH_NULL_SHA256: drop MAC */
871 /* else: no encryption yet on input, subtract zero = NOP */
872 sz -= tls->min_encrypted_len_on_read;
875 bb_error_msg_and_die("encrypted data too short");
877 //dump_hex("<< %s\n", tls->inbuf, RECHDR_LEN + sz);
879 xhdr = (void*)tls->inbuf;
880 if (xhdr->type == RECORD_TYPE_ALERT && sz >= 2) {
881 uint8_t *p = tls->inbuf + RECHDR_LEN;
882 dbg("ALERT size:%d level:%d description:%d\n", sz, p[0], p[1]);
883 if (p[0] == 2) { /* fatal */
884 bb_error_msg_and_die("TLS %s from peer (alert code %d): %s",
886 p[1], alert_text(p[1])
889 if (p[0] == 1) { /* warning */
890 if (p[1] == 0) { /* "close_notify" warning: it's EOF */
891 dbg("EOF (TLS encoded) from peer\n");
895 //This possibly needs to be cached and shown only if
896 //a fatal alert follows
897 // bb_error_msg("TLS %s from peer (alert code %d): %s",
899 // p[1], alert_text(p[1])
901 /* discard it, get next record */
904 /* p[0] not 1 or 2: not defined in protocol */
909 /* RFC 5246 is not saying it explicitly, but sha256 hash
910 * in our FINISHED record must include data of incoming packets too!
912 if (tls->inbuf[0] == RECORD_TYPE_HANDSHAKE
913 && tls->MAC_size != 0 /* do we know which hash to use? (server_hello() does not!) */
915 hash_handshake(tls, "<< hash:%s", tls->inbuf + RECHDR_LEN, sz);
918 dbg("got block len:%u\n", sz);
923 * DER parsing routines
925 static unsigned get_der_len(uint8_t **bodyp, uint8_t *der, uint8_t *end)
931 // if ((der[0] & 0x1f) == 0x1f) /* not single-byte item code? */
934 len = der[1]; /* maybe it's short len */
938 if (len == 0x80 || end - der < (int)(len - 0x7e)) {
939 /* 0x80 is "0 bytes of len", invalid DER: must use short len if can */
940 /* need 3 or 4 bytes for 81, 82 */
944 len1 = der[2]; /* if (len == 0x81) it's "ii 81 xx", fetch xx */
946 /* >0x82 is "3+ bytes of len", should not happen realistically */
949 if (len == 0x82) { /* it's "ii 82 xx yy" */
950 len1 = 0x100*len1 + der[3];
951 der += 1; /* skip [yy] */
953 der += 1; /* skip [xx] */
956 // xfunc_die(); /* invalid DER: must use short len if can */
958 der += 2; /* skip [code]+[1byte] */
960 if (end - der < (int)len)
967 static uint8_t *enter_der_item(uint8_t *der, uint8_t **endp)
970 unsigned len = get_der_len(&new_der, der, *endp);
971 dbg_der("entered der @%p:0x%02x len:%u inner_byte @%p:0x%02x\n", der, der[0], len, new_der, new_der[0]);
972 /* Move "end" position to cover only this item */
973 *endp = new_der + len;
977 static uint8_t *skip_der_item(uint8_t *der, uint8_t *end)
980 unsigned len = get_der_len(&new_der, der, end);
983 dbg_der("skipped der 0x%02x, next byte 0x%02x\n", der[0], new_der[0]);
987 static void der_binary_to_pstm(pstm_int *pstm_n, uint8_t *der, uint8_t *end)
990 unsigned len = get_der_len(&bin_ptr, der, end);
992 dbg_der("binary bytes:%u, first:0x%02x\n", len, bin_ptr[0]);
993 pstm_init_for_read_unsigned_bin(/*pool:*/ NULL, pstm_n, len);
994 pstm_read_unsigned_bin(pstm_n, bin_ptr, len);
998 static void find_key_in_der_cert(tls_state_t *tls, uint8_t *der, int len)
1000 /* Certificate is a DER-encoded data structure. Each DER element has a length,
1001 * which makes it easy to skip over large compound elements of any complexity
1002 * without parsing them. Example: partial decode of kernel.org certificate:
1003 * SEQ 0x05ac/1452 bytes (Certificate): 308205ac
1004 * SEQ 0x0494/1172 bytes (tbsCertificate): 30820494
1005 * [ASN_CONTEXT_SPECIFIC | ASN_CONSTRUCTED | 0] 3 bytes: a003
1006 * INTEGER (version): 0201 02
1007 * INTEGER 0x11 bytes (serialNumber): 0211 00 9f85bf664b0cddafca508679501b2be4
1008 * //^^^^^^note: matrixSSL also allows [ASN_CONTEXT_SPECIFIC | ASN_PRIMITIVE | 2] = 0x82 type
1009 * SEQ 0x0d bytes (signatureAlgo): 300d
1010 * OID 9 bytes: 0609 2a864886f70d01010b (OID_SHA256_RSA_SIG 42.134.72.134.247.13.1.1.11)
1012 * SEQ 0x5f bytes (issuer): 305f
1013 * SET 11 bytes: 310b
1015 * OID 3 bytes: 0603 550406
1016 * Printable string "FR": 1302 4652
1017 * SET 14 bytes: 310e
1018 * SEQ 12 bytes: 300c
1019 * OID 3 bytes: 0603 550408
1020 * Printable string "Paris": 1305 5061726973
1021 * SET 14 bytes: 310e
1022 * SEQ 12 bytes: 300c
1023 * OID 3 bytes: 0603 550407
1024 * Printable string "Paris": 1305 5061726973
1025 * SET 14 bytes: 310e
1026 * SEQ 12 bytes: 300c
1027 * OID 3 bytes: 0603 55040a
1028 * Printable string "Gandi": 1305 47616e6469
1029 * SET 32 bytes: 3120
1030 * SEQ 30 bytes: 301e
1031 * OID 3 bytes: 0603 550403
1032 * Printable string "Gandi Standard SSL CA 2": 1317 47616e6469205374616e646172642053534c2043412032
1033 * SEQ 30 bytes (validity): 301e
1034 * TIME "161011000000Z": 170d 3136313031313030303030305a
1035 * TIME "191011235959Z": 170d 3139313031313233353935395a
1036 * SEQ 0x5b/91 bytes (subject): 305b //I did not decode this
1037 * 3121301f060355040b1318446f6d61696e20436f
1038 * 6e74726f6c2056616c6964617465643121301f06
1039 * 0355040b1318506f73697469766553534c204d75
1040 * 6c74692d446f6d61696e31133011060355040313
1041 * 0a6b65726e656c2e6f7267
1042 * SEQ 0x01a2/418 bytes (subjectPublicKeyInfo): 308201a2
1043 * SEQ 13 bytes (algorithm): 300d
1044 * OID 9 bytes: 0609 2a864886f70d010101 (OID_RSA_KEY_ALG 42.134.72.134.247.13.1.1.1)
1046 * BITSTRING 0x018f/399 bytes (publicKey): 0382018f
1048 * //after the zero byte, it appears key itself uses DER encoding:
1049 * SEQ 0x018a/394 bytes: 3082018a
1050 * INTEGER 0x0181/385 bytes (modulus): 02820181
1051 * 00b1ab2fc727a3bef76780c9349bf3
1052 * ...24 more blocks of 15 bytes each...
1053 * 90e895291c6bc8693b65
1054 * INTEGER 3 bytes (exponent): 0203 010001
1055 * [ASN_CONTEXT_SPECIFIC | ASN_CONSTRUCTED | 0x3] 0x01e5 bytes (X509v3 extensions): a38201e5
1056 * SEQ 0x01e1 bytes: 308201e1
1058 * Certificate is a sequence of three elements:
1059 * tbsCertificate (SEQ)
1060 * signatureAlgorithm (AlgorithmIdentifier)
1061 * signatureValue (BIT STRING)
1063 * In turn, tbsCertificate is a sequence of:
1066 * signatureAlgo (AlgorithmIdentifier)
1067 * issuer (Name, has complex structure)
1068 * validity (Validity, SEQ of two Times)
1070 * subjectPublicKeyInfo (SEQ)
1073 * subjectPublicKeyInfo is a sequence of:
1074 * algorithm (AlgorithmIdentifier)
1075 * publicKey (BIT STRING)
1077 * We need Certificate.tbsCertificate.subjectPublicKeyInfo.publicKey
1079 uint8_t *end = der + len;
1081 /* enter "Certificate" item: [der, end) will be only Cert */
1082 der = enter_der_item(der, &end);
1084 /* enter "tbsCertificate" item: [der, end) will be only tbsCert */
1085 der = enter_der_item(der, &end);
1087 /* skip up to subjectPublicKeyInfo */
1088 der = skip_der_item(der, end); /* version */
1089 der = skip_der_item(der, end); /* serialNumber */
1090 der = skip_der_item(der, end); /* signatureAlgo */
1091 der = skip_der_item(der, end); /* issuer */
1092 der = skip_der_item(der, end); /* validity */
1093 der = skip_der_item(der, end); /* subject */
1095 /* enter subjectPublicKeyInfo */
1096 der = enter_der_item(der, &end);
1097 { /* check subjectPublicKeyInfo.algorithm */
1098 static const uint8_t expected[] = {
1099 0x30,0x0d, // SEQ 13 bytes
1100 0x06,0x09, 0x2a,0x86,0x48,0x86,0xf7,0x0d,0x01,0x01,0x01, // OID RSA_KEY_ALG 42.134.72.134.247.13.1.1.1
1101 //0x05,0x00, // NULL
1103 if (memcmp(der, expected, sizeof(expected)) != 0)
1104 bb_error_msg_and_die("not RSA key");
1106 /* skip subjectPublicKeyInfo.algorithm */
1107 der = skip_der_item(der, end);
1108 /* enter subjectPublicKeyInfo.publicKey */
1109 // die_if_not_this_der_type(der, end, 0x03); /* must be BITSTRING */
1110 der = enter_der_item(der, &end);
1112 /* parse RSA key: */
1113 //based on getAsnRsaPubKey(), pkcs1ParsePrivBin() is also of note
1114 dbg("key bytes:%u, first:0x%02x\n", (int)(end - der), der[0]);
1115 if (end - der < 14) xfunc_die();
1118 * SEQ 0x018a/394 bytes: 3082018a
1119 * INTEGER 0x0181/385 bytes (modulus): 02820181 XX...XXX
1120 * INTEGER 3 bytes (exponent): 0203 010001
1122 if (*der != 0) /* "ignore bits", should be 0 */
1125 der = enter_der_item(der, &end); /* enter SEQ */
1126 /* memset(tls->hsd->server_rsa_pub_key, 0, sizeof(tls->hsd->server_rsa_pub_key)); - already is */
1127 der_binary_to_pstm(&tls->hsd->server_rsa_pub_key.N, der, end); /* modulus */
1128 der = skip_der_item(der, end);
1129 der_binary_to_pstm(&tls->hsd->server_rsa_pub_key.e, der, end); /* exponent */
1130 tls->hsd->server_rsa_pub_key.size = pstm_unsigned_bin_size(&tls->hsd->server_rsa_pub_key.N);
1131 dbg("server_rsa_pub_key.size:%d\n", tls->hsd->server_rsa_pub_key.size);
1135 * TLS Handshake routines
1137 static int tls_xread_handshake_block(tls_state_t *tls, int min_len)
1139 struct record_hdr *xhdr;
1140 int len = tls_xread_record(tls);
1142 xhdr = (void*)tls->inbuf;
1144 || xhdr->type != RECORD_TYPE_HANDSHAKE
1145 || xhdr->proto_maj != TLS_MAJ
1146 || xhdr->proto_min != TLS_MIN
1148 bad_record_die(tls, "handshake record", len);
1150 dbg("got HANDSHAKE\n");
1154 static ALWAYS_INLINE void fill_handshake_record_hdr(void *buf, unsigned type, unsigned len)
1156 struct handshake_hdr {
1158 uint8_t len24_hi, len24_mid, len24_lo;
1163 h->len24_hi = len >> 16;
1164 h->len24_mid = len >> 8;
1165 h->len24_lo = len & 0xff;
1168 static void send_client_hello_and_alloc_hsd(tls_state_t *tls, const char *sni)
1170 struct client_hello {
1172 uint8_t len24_hi, len24_mid, len24_lo;
1173 uint8_t proto_maj, proto_min;
1175 uint8_t session_id_len;
1176 /* uint8_t session_id[]; */
1177 uint8_t cipherid_len16_hi, cipherid_len16_lo;
1178 uint8_t cipherid[2 * (2 + !!CIPHER_ID2)]; /* actually variable */
1179 uint8_t comprtypes_len;
1180 uint8_t comprtypes[1]; /* actually variable */
1181 /* Extensions (SNI shown):
1182 * hi,lo // len of all extensions
1183 * 00,00 // extension_type: "Server Name"
1184 * 00,0e // list len (there can be more than one SNI)
1185 * 00,0c // len of 1st Server Name Indication
1186 * 00 // name type: host_name
1188 * "localhost" // name
1190 // GNU Wget 1.18 to cdn.kernel.org sends these extensions:
1192 // 0005 0005 0100000000 - status_request
1193 // 0000 0013 0011 00 000e 63646e 2e 6b65726e656c 2e 6f7267 - server_name
1194 // ff01 0001 00 - renegotiation_info
1195 // 0023 0000 - session_ticket
1196 // 000a 0008 0006001700180019 - supported_groups
1197 // 000b 0002 0100 - ec_point_formats
1198 // 000d 0016 00140401040305010503060106030301030302010203 - signature_algorithms
1200 struct client_hello *record;
1202 int sni_len = sni ? strnlen(sni, 127 - 9) : 0;
1204 len = sizeof(*record);
1206 len += 11 + sni_len;
1207 record = tls_get_outbuf(tls, len);
1208 memset(record, 0, len);
1210 fill_handshake_record_hdr(record, HANDSHAKE_CLIENT_HELLO, len);
1211 record->proto_maj = TLS_MAJ; /* the "requested" version of the protocol, */
1212 record->proto_min = TLS_MIN; /* can be higher than one in record headers */
1213 tls_get_random(record->rand32, sizeof(record->rand32));
1214 if (TLS_DEBUG_FIXED_SECRETS)
1215 memset(record->rand32, 0x11, sizeof(record->rand32));
1216 /* record->session_id_len = 0; - already is */
1218 /* record->cipherid_len16_hi = 0; */
1219 record->cipherid_len16_lo = sizeof(record->cipherid);
1220 /* RFC 5746 Renegotiation Indication Extension - some servers will refuse to work with us otherwise */
1221 /*record->cipherid[0] = TLS_EMPTY_RENEGOTIATION_INFO_SCSV >> 8; - zero */
1222 record->cipherid[1] = TLS_EMPTY_RENEGOTIATION_INFO_SCSV & 0xff;
1223 if ((CIPHER_ID1 >> 8) != 0) record->cipherid[2] = CIPHER_ID1 >> 8;
1224 /*************************/ record->cipherid[3] = CIPHER_ID1 & 0xff;
1226 if ((CIPHER_ID2 >> 8) != 0) record->cipherid[4] = CIPHER_ID2 >> 8;
1227 /*************************/ record->cipherid[5] = CIPHER_ID2 & 0xff;
1230 record->comprtypes_len = 1;
1231 /* record->comprtypes[0] = 0; */
1234 uint8_t *p = (void*)(record + 1);
1236 p[1] = sni_len + 9; //ext_len
1238 //p[3] = 0; //extension_type
1240 p[5] = sni_len + 5; //list len
1242 p[7] = sni_len + 3; //len of 1st SNI
1243 //p[8] = 0; //name type
1245 p[10] = sni_len; //name len
1246 memcpy(&p[11], sni, sni_len);
1249 dbg(">> CLIENT_HELLO\n");
1250 /* Can hash it only when we know which MAC hash to use */
1251 /*xwrite_and_update_handshake_hash(tls, len); - WRONG! */
1252 xwrite_handshake_record(tls, len);
1254 tls->hsd = xzalloc(sizeof(*tls->hsd) + len);
1255 tls->hsd->saved_client_hello_size = len;
1256 memcpy(tls->hsd->saved_client_hello, record, len);
1257 memcpy(tls->hsd->client_and_server_rand32, record->rand32, sizeof(record->rand32));
1260 static void get_server_hello(tls_state_t *tls)
1262 struct server_hello {
1263 struct record_hdr xhdr;
1265 uint8_t len24_hi, len24_mid, len24_lo;
1266 uint8_t proto_maj, proto_min;
1267 uint8_t rand32[32]; /* first 4 bytes are unix time in BE format */
1268 uint8_t session_id_len;
1269 uint8_t session_id[32];
1270 uint8_t cipherid_hi, cipherid_lo;
1272 /* extensions may follow, but only those which client offered in its Hello */
1275 struct server_hello *hp;
1280 len = tls_xread_handshake_block(tls, 74 - 32);
1282 hp = (void*)tls->inbuf;
1284 // 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|
1285 //SvHl len=70 maj.min unixtime^^^ 28randbytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^ slen sid32bytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cipSel comprSel
1286 if (hp->type != HANDSHAKE_SERVER_HELLO
1287 || hp->len24_hi != 0
1288 || hp->len24_mid != 0
1289 /* hp->len24_lo checked later */
1290 || hp->proto_maj != TLS_MAJ
1291 || hp->proto_min != TLS_MIN
1293 bad_record_die(tls, "'server hello'", len);
1296 cipherid = &hp->cipherid_hi;
1297 len24 = hp->len24_lo;
1298 if (hp->session_id_len != 32) {
1299 if (hp->session_id_len != 0)
1300 bad_record_die(tls, "'server hello'", len);
1302 // session_id_len == 0: no session id
1304 // may return an empty session_id to indicate that the session will
1305 // not be cached and therefore cannot be resumed."
1307 len24 += 32; /* what len would be if session id would be present */
1311 // || cipherid[0] != (CIPHER_ID >> 8)
1312 // || cipherid[1] != (CIPHER_ID & 0xff)
1313 // || cipherid[2] != 0 /* comprtype */
1315 bad_record_die(tls, "'server hello'", len);
1317 dbg("<< SERVER_HELLO\n");
1319 memcpy(tls->hsd->client_and_server_rand32 + 32, hp->rand32, sizeof(hp->rand32));
1321 tls->cipher_id = cipher = 0x100 * cipherid[0] + cipherid[1];
1322 dbg("server chose cipher %04x\n", cipher);
1324 if (cipher == TLS_RSA_WITH_AES_128_CBC_SHA) {
1325 tls->key_size = AES128_KEYSIZE;
1326 tls->MAC_size = SHA1_OUTSIZE;
1328 else { /* TLS_RSA_WITH_AES_256_CBC_SHA256 */
1329 tls->key_size = AES256_KEYSIZE;
1330 tls->MAC_size = SHA256_OUTSIZE;
1332 /* Handshake hash eventually destined to FINISHED record
1333 * is sha256 regardless of cipher
1334 * (at least for all ciphers defined by RFC5246).
1335 * It's not sha1 for AES_128_CBC_SHA - only MAC is sha1, not this hash.
1337 sha256_begin(&tls->hsd->handshake_hash_ctx);
1338 hash_handshake(tls, ">> client hello hash:%s",
1339 tls->hsd->saved_client_hello, tls->hsd->saved_client_hello_size
1341 hash_handshake(tls, "<< server hello hash:%s",
1342 tls->inbuf + RECHDR_LEN, len
1346 static void get_server_cert(tls_state_t *tls)
1348 struct record_hdr *xhdr;
1352 len = tls_xread_handshake_block(tls, 10);
1354 xhdr = (void*)tls->inbuf;
1355 certbuf = (void*)(xhdr + 1);
1356 if (certbuf[0] != HANDSHAKE_CERTIFICATE)
1358 dbg("<< CERTIFICATE\n");
1360 // 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...
1361 //Cert len=4388 ChainLen CertLen^ DER encoded X509 starts here. openssl x509 -in FILE -inform DER -noout -text
1362 len1 = get24be(certbuf + 1);
1363 if (len1 > len - 4) tls_error_die(tls);
1365 len1 = get24be(certbuf + 4);
1366 if (len1 > len - 3) tls_error_die(tls);
1368 len1 = get24be(certbuf + 7);
1369 if (len1 > len - 3) tls_error_die(tls);
1373 find_key_in_der_cert(tls, certbuf + 10, len);
1376 static void send_empty_client_cert(tls_state_t *tls)
1378 struct client_empty_cert {
1380 uint8_t len24_hi, len24_mid, len24_lo;
1381 uint8_t cert_chain_len24_hi, cert_chain_len24_mid, cert_chain_len24_lo;
1383 struct client_empty_cert *record;
1385 record = tls_get_outbuf(tls, sizeof(*record));
1386 //FIXME: can just memcpy a ready-made one.
1387 fill_handshake_record_hdr(record, HANDSHAKE_CERTIFICATE, sizeof(*record));
1388 record->cert_chain_len24_hi = 0;
1389 record->cert_chain_len24_mid = 0;
1390 record->cert_chain_len24_lo = 0;
1392 dbg(">> CERTIFICATE\n");
1393 xwrite_and_update_handshake_hash(tls, sizeof(*record));
1396 static void send_client_key_exchange(tls_state_t *tls)
1398 struct client_key_exchange {
1400 uint8_t len24_hi, len24_mid, len24_lo;
1401 /* keylen16 exists for RSA (in TLS, not in SSL), but not for some other key types */
1402 uint8_t keylen16_hi, keylen16_lo;
1403 uint8_t key[4 * 1024]; // size??
1405 //FIXME: better size estimate
1406 struct client_key_exchange *record = tls_get_outbuf(tls, sizeof(*record));
1407 uint8_t rsa_premaster[RSA_PREMASTER_SIZE];
1410 tls_get_random(rsa_premaster, sizeof(rsa_premaster));
1411 if (TLS_DEBUG_FIXED_SECRETS)
1412 memset(rsa_premaster, 0x44, sizeof(rsa_premaster));
1414 // "Note: The version number in the PreMasterSecret is the version
1415 // offered by the client in the ClientHello.client_version, not the
1416 // version negotiated for the connection."
1417 rsa_premaster[0] = TLS_MAJ;
1418 rsa_premaster[1] = TLS_MIN;
1419 dump_hex("premaster:%s\n", rsa_premaster, sizeof(rsa_premaster));
1420 len = psRsaEncryptPub(/*pool:*/ NULL,
1421 /* psRsaKey_t* */ &tls->hsd->server_rsa_pub_key,
1422 rsa_premaster, /*inlen:*/ sizeof(rsa_premaster),
1423 record->key, sizeof(record->key),
1426 record->keylen16_hi = len >> 8;
1427 record->keylen16_lo = len & 0xff;
1429 record->type = HANDSHAKE_CLIENT_KEY_EXCHANGE;
1430 record->len24_hi = 0;
1431 record->len24_mid = len >> 8;
1432 record->len24_lo = len & 0xff;
1435 dbg(">> CLIENT_KEY_EXCHANGE\n");
1436 xwrite_and_update_handshake_hash(tls, len);
1439 // For all key exchange methods, the same algorithm is used to convert
1440 // the pre_master_secret into the master_secret. The pre_master_secret
1441 // should be deleted from memory once the master_secret has been
1443 // master_secret = PRF(pre_master_secret, "master secret",
1444 // ClientHello.random + ServerHello.random)
1446 // The master secret is always exactly 48 bytes in length. The length
1447 // of the premaster secret will vary depending on key exchange method.
1448 prf_hmac_sha256(/*tls,*/
1449 tls->hsd->master_secret, sizeof(tls->hsd->master_secret),
1450 rsa_premaster, sizeof(rsa_premaster),
1452 tls->hsd->client_and_server_rand32, sizeof(tls->hsd->client_and_server_rand32)
1454 dump_hex("master secret:%s\n", tls->hsd->master_secret, sizeof(tls->hsd->master_secret));
1457 // 6.3. Key Calculation
1459 // The Record Protocol requires an algorithm to generate keys required
1460 // by the current connection state (see Appendix A.6) from the security
1461 // parameters provided by the handshake protocol.
1463 // The master secret is expanded into a sequence of secure bytes, which
1464 // is then split to a client write MAC key, a server write MAC key, a
1465 // client write encryption key, and a server write encryption key. Each
1466 // of these is generated from the byte sequence in that order. Unused
1467 // values are empty. Some AEAD ciphers may additionally require a
1468 // client write IV and a server write IV (see Section 6.2.3.3).
1470 // When keys and MAC keys are generated, the master secret is used as an
1473 // To generate the key material, compute
1475 // key_block = PRF(SecurityParameters.master_secret,
1477 // SecurityParameters.server_random +
1478 // SecurityParameters.client_random);
1480 // until enough output has been generated. Then, the key_block is
1481 // partitioned as follows:
1483 // client_write_MAC_key[SecurityParameters.mac_key_length]
1484 // server_write_MAC_key[SecurityParameters.mac_key_length]
1485 // client_write_key[SecurityParameters.enc_key_length]
1486 // server_write_key[SecurityParameters.enc_key_length]
1487 // client_write_IV[SecurityParameters.fixed_iv_length]
1488 // server_write_IV[SecurityParameters.fixed_iv_length]
1492 /* make "server_rand32 + client_rand32" */
1493 memcpy(&tmp64[0] , &tls->hsd->client_and_server_rand32[32], 32);
1494 memcpy(&tmp64[32], &tls->hsd->client_and_server_rand32[0] , 32);
1496 prf_hmac_sha256(/*tls,*/
1497 tls->client_write_MAC_key, 2 * (tls->MAC_size + tls->key_size),
1499 // server_write_MAC_key[]
1500 // client_write_key[]
1501 // server_write_key[]
1502 tls->hsd->master_secret, sizeof(tls->hsd->master_secret),
1506 tls->client_write_key = tls->client_write_MAC_key + (2 * tls->MAC_size);
1507 tls->server_write_key = tls->client_write_key + tls->key_size;
1508 dump_hex("client_write_MAC_key:%s\n",
1509 tls->client_write_MAC_key, tls->MAC_size
1511 dump_hex("client_write_key:%s\n",
1512 tls->client_write_key, tls->key_size
1517 static const uint8_t rec_CHANGE_CIPHER_SPEC[] = {
1518 RECORD_TYPE_CHANGE_CIPHER_SPEC, TLS_MAJ, TLS_MIN, 00, 01,
1522 static void send_change_cipher_spec(tls_state_t *tls)
1524 dbg(">> CHANGE_CIPHER_SPEC\n");
1525 xwrite(tls->ofd, rec_CHANGE_CIPHER_SPEC, sizeof(rec_CHANGE_CIPHER_SPEC));
1529 // A Finished message is always sent immediately after a change
1530 // cipher spec message to verify that the key exchange and
1531 // authentication processes were successful. It is essential that a
1532 // change cipher spec message be received between the other handshake
1533 // messages and the Finished message.
1535 // The Finished message is the first one protected with the just
1536 // negotiated algorithms, keys, and secrets. Recipients of Finished
1537 // messages MUST verify that the contents are correct. Once a side
1538 // has sent its Finished message and received and validated the
1539 // Finished message from its peer, it may begin to send and receive
1540 // application data over the connection.
1543 // opaque verify_data[verify_data_length];
1547 // PRF(master_secret, finished_label, Hash(handshake_messages))
1548 // [0..verify_data_length-1];
1551 // For Finished messages sent by the client, the string
1552 // "client finished". For Finished messages sent by the server,
1553 // the string "server finished".
1555 // Hash denotes a Hash of the handshake messages. For the PRF
1556 // defined in Section 5, the Hash MUST be the Hash used as the basis
1557 // for the PRF. Any cipher suite which defines a different PRF MUST
1558 // also define the Hash to use in the Finished computation.
1560 // In previous versions of TLS, the verify_data was always 12 octets
1561 // long. In the current version of TLS, it depends on the cipher
1562 // suite. Any cipher suite which does not explicitly specify
1563 // verify_data_length has a verify_data_length equal to 12. This
1564 // includes all existing cipher suites.
1565 static void send_client_finished(tls_state_t *tls)
1569 uint8_t len24_hi, len24_mid, len24_lo;
1570 uint8_t prf_result[12];
1572 struct finished *record = tls_get_outbuf(tls, sizeof(*record));
1573 uint8_t handshake_hash[TLS_MAX_MAC_SIZE];
1576 fill_handshake_record_hdr(record, HANDSHAKE_FINISHED, sizeof(*record));
1578 len = get_handshake_hash(tls, handshake_hash);
1579 prf_hmac_sha256(/*tls,*/
1580 record->prf_result, sizeof(record->prf_result),
1581 tls->hsd->master_secret, sizeof(tls->hsd->master_secret),
1585 dump_hex("from secret: %s\n", tls->hsd->master_secret, sizeof(tls->hsd->master_secret));
1586 dump_hex("from labelSeed: %s", "client finished", sizeof("client finished")-1);
1587 dump_hex("%s\n", handshake_hash, sizeof(handshake_hash));
1588 dump_hex("=> digest: %s\n", record->prf_result, sizeof(record->prf_result));
1590 dbg(">> FINISHED\n");
1591 xwrite_encrypted(tls, sizeof(*record), RECORD_TYPE_HANDSHAKE);
1594 void FAST_FUNC tls_handshake(tls_state_t *tls, const char *sni)
1596 // Client RFC 5246 Server
1597 // (*) - optional messages, not always sent
1599 // ClientHello ------->
1602 // ServerKeyExchange*
1603 // CertificateRequest*
1604 // <------- ServerHelloDone
1606 // ClientKeyExchange
1607 // CertificateVerify*
1608 // [ChangeCipherSpec]
1609 // Finished ------->
1610 // [ChangeCipherSpec]
1611 // <------- Finished
1612 // Application Data <------> Application Data
1615 send_client_hello_and_alloc_hsd(tls, sni);
1616 get_server_hello(tls);
1619 // The server MUST send a Certificate message whenever the agreed-
1620 // upon key exchange method uses certificates for authentication
1621 // (this includes all key exchange methods defined in this document
1622 // except DH_anon). This message will always immediately follow the
1623 // ServerHello message.
1625 // IOW: in practice, Certificate *always* follows.
1626 // (for example, kernel.org does not even accept DH_anon cipher id)
1627 get_server_cert(tls);
1629 len = tls_xread_handshake_block(tls, 4);
1630 if (tls->inbuf[RECHDR_LEN] == HANDSHAKE_SERVER_KEY_EXCHANGE) {
1632 // 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...
1634 // with TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA: 461 bytes:
1635 // 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...
1636 dbg("<< SERVER_KEY_EXCHANGE len:%u\n", len);
1637 //probably need to save it
1638 len = tls_xread_handshake_block(tls, 4);
1641 if (tls->inbuf[RECHDR_LEN] == HANDSHAKE_CERTIFICATE_REQUEST) {
1642 dbg("<< CERTIFICATE_REQUEST\n");
1643 // RFC 5246: "If no suitable certificate is available,
1644 // the client MUST send a certificate message containing no
1645 // certificates. That is, the certificate_list structure has a
1646 // length of zero. ...
1647 // Client certificates are sent using the Certificate structure
1648 // defined in Section 7.4.2."
1649 // (i.e. the same format as server certs)
1650 send_empty_client_cert(tls);
1651 len = tls_xread_handshake_block(tls, 4);
1654 if (tls->inbuf[RECHDR_LEN] != HANDSHAKE_SERVER_HELLO_DONE) {
1655 bad_record_die(tls, "'server hello done'", len);
1657 // 0e 000000 (len:0)
1658 dbg("<< SERVER_HELLO_DONE\n");
1660 send_client_key_exchange(tls);
1662 send_change_cipher_spec(tls);
1663 /* from now on we should send encrypted */
1664 /* tls->write_seq64_be = 0; - already is */
1665 tls->encrypt_on_write = 1;
1667 send_client_finished(tls);
1669 /* Get CHANGE_CIPHER_SPEC */
1670 len = tls_xread_record(tls);
1671 if (len != 1 || memcmp(tls->inbuf, rec_CHANGE_CIPHER_SPEC, 6) != 0)
1672 bad_record_die(tls, "switch to encrypted traffic", len);
1673 dbg("<< CHANGE_CIPHER_SPEC\n");
1674 if (CIPHER_ID1 == TLS_RSA_WITH_NULL_SHA256
1675 && tls->cipher_id == TLS_RSA_WITH_NULL_SHA256
1677 tls->min_encrypted_len_on_read = tls->MAC_size;
1679 unsigned mac_blocks = (unsigned)(tls->MAC_size + AES_BLOCKSIZE-1) / AES_BLOCKSIZE;
1680 /* all incoming packets now should be encrypted and have
1681 * at least IV + (MAC padded to blocksize):
1683 tls->min_encrypted_len_on_read = AES_BLOCKSIZE + (mac_blocks * AES_BLOCKSIZE);
1684 dbg("min_encrypted_len_on_read: %u", tls->min_encrypted_len_on_read);
1687 /* Get (encrypted) FINISHED from the server */
1688 len = tls_xread_record(tls);
1689 if (len < 4 || tls->inbuf[RECHDR_LEN] != HANDSHAKE_FINISHED)
1691 dbg("<< FINISHED\n");
1692 /* application data can be sent/received */
1694 /* free handshake data */
1696 // memset(tls->hsd, 0, tls->hsd->hsd_size);
1701 static void tls_xwrite(tls_state_t *tls, int len)
1704 xwrite_encrypted(tls, len, RECORD_TYPE_APPLICATION_DATA);
1707 // To run a test server using openssl:
1708 // openssl req -x509 -newkey rsa:$((4096/4*3)) -keyout key.pem -out server.pem -nodes -days 99999 -subj '/CN=localhost'
1709 // openssl s_server -key key.pem -cert server.pem -debug -tls1_2 -no_tls1 -no_tls1_1
1711 // Unencryped SHA256 example:
1712 // openssl req -x509 -newkey rsa:$((4096/4*3)) -keyout key.pem -out server.pem -nodes -days 99999 -subj '/CN=localhost'
1713 // openssl s_server -key key.pem -cert server.pem -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher NULL
1714 // openssl s_client -connect 127.0.0.1:4433 -debug -tls1_2 -no_tls1 -no_tls1_1 -cipher NULL-SHA256
1716 void FAST_FUNC tls_run_copy_loop(tls_state_t *tls)
1719 const int INBUF_STEP = 4 * 1024;
1720 struct pollfd pfds[2];
1722 pfds[0].fd = STDIN_FILENO;
1723 pfds[0].events = POLLIN;
1724 pfds[1].fd = tls->ifd;
1725 pfds[1].events = POLLIN;
1727 inbuf_size = INBUF_STEP;
1731 if (safe_poll(pfds, 2, -1) < 0)
1732 bb_perror_msg_and_die("poll");
1734 if (pfds[0].revents) {
1737 dbg("STDIN HAS DATA\n");
1738 buf = tls_get_outbuf(tls, inbuf_size);
1739 nread = safe_read(STDIN_FILENO, buf, inbuf_size);
1741 /* We'd want to do this: */
1742 /* Close outgoing half-connection so they get EOF,
1743 * but leave incoming alone so we can see response
1745 //shutdown(tls->ofd, SHUT_WR);
1746 /* But TLS has no way to encode this,
1747 * doubt it's ok to do it "raw"
1750 tls_free_outbuf(tls); /* mem usage optimization */
1752 if (nread == inbuf_size) {
1753 /* TLS has per record overhead, if input comes fast,
1754 * read, encrypt and send bigger chunks
1756 inbuf_size += INBUF_STEP;
1757 if (inbuf_size > TLS_MAX_OUTBUF)
1758 inbuf_size = TLS_MAX_OUTBUF;
1760 tls_xwrite(tls, nread);
1763 if (pfds[1].revents) {
1764 dbg("NETWORK HAS DATA\n");
1766 nread = tls_xread_record(tls);
1768 /* TLS protocol has no real concept of one-sided shutdowns:
1769 * if we get "TLS EOF" from the peer, writes will fail too
1772 //close(STDOUT_FILENO);
1773 //tls_free_inbuf(tls); /* mem usage optimization */
1777 if (tls->inbuf[0] != RECORD_TYPE_APPLICATION_DATA)
1778 bb_error_msg_and_die("unexpected record type %d", tls->inbuf[0]);
1779 xwrite(STDOUT_FILENO, tls->inbuf + RECHDR_LEN, nread);
1780 /* We may already have a complete next record buffered,
1781 * can process it without network reads (and possible blocking)
1783 if (tls_has_buffered_record(tls))