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 //Config.src also defines FEATURE_TLS_SHA1 option
12 //kbuild:lib-$(CONFIG_TLS) += tls.o
13 //kbuild:lib-$(CONFIG_TLS) += tls_pstm.o
14 //kbuild:lib-$(CONFIG_TLS) += tls_pstm_montgomery_reduce.o
15 //kbuild:lib-$(CONFIG_TLS) += tls_pstm_mul_comba.o
16 //kbuild:lib-$(CONFIG_TLS) += tls_pstm_sqr_comba.o
17 //kbuild:lib-$(CONFIG_TLS) += tls_aes.o
18 //kbuild:lib-$(CONFIG_TLS) += tls_aesgcm.o
19 //kbuild:lib-$(CONFIG_TLS) += tls_rsa.o
20 //kbuild:lib-$(CONFIG_TLS) += tls_fe.o
24 // works against "openssl s_server -cipher NULL"
25 // and against wolfssl-3.9.10-stable/examples/server/server.c:
26 #define ALLOW_RSA_NULL_SHA256 0 // for testing (does everything except encrypting)
28 //Tested against kernel.org:
29 //#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA // ok, recvs SERVER_KEY_EXCHANGE *** matrixssl uses this on my box
30 //#define CIPHER_ID TLS_RSA_WITH_AES_256_CBC_SHA256 // ok, no SERVER_KEY_EXCHANGE
31 //#define CIPHER_ID TLS_DH_anon_WITH_AES_256_CBC_SHA // SSL_ALERT_HANDSHAKE_FAILURE
32 //^^^^^^^^^^^^^^^^^^^^^^^ (tested b/c this one doesn't req server certs... no luck, server refuses it)
33 //#define CIPHER_ID TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 // SSL_ALERT_HANDSHAKE_FAILURE
34 //#define CIPHER_ID TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
35 //#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 // ok, recvs SERVER_KEY_EXCHANGE
36 //#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
37 //#define CIPHER_ID TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384
38 //#define CIPHER_ID TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
39 //#define CIPHER_ID TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384
40 //#define CIPHER_ID TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
41 //#define CIPHER_ID TLS_RSA_WITH_AES_256_GCM_SHA384 // ok, no SERVER_KEY_EXCHANGE
42 //#define CIPHER_ID TLS_RSA_WITH_AES_128_GCM_SHA256 // ok, no SERVER_KEY_EXCHANGE
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 -cipher AES256-SHA256
50 // fail: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -cipher AES256-GCM-SHA384
51 // fail: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -cipher AES128-SHA256
52 // ok: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -cipher AES128-GCM-SHA256
53 // ok: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -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 //0x003D
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 //0x002F
60 // ftp.openbsd.org only supports ECDHE-RSA-AESnnn-GCM-SHAnnn or ECDHE-RSA-CHACHA20-POLY1305
61 //#define CIPHER_ID3 TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 //0xC02F
62 // host is.gd accepts only ECDHE-ECDSA-foo (the simplest which works: ECDHE-ECDSA-AES128-SHA 0xC009)
63 //#define CIPHER_ID4 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA //0xC009
67 #define TLS_DEBUG_HASH 0
68 #define TLS_DEBUG_DER 0
69 #define TLS_DEBUG_FIXED_SECRETS 0
71 # define dump_raw_out(...) dump_hex(__VA_ARGS__)
73 # define dump_raw_out(...) ((void)0)
76 # define dump_raw_in(...) dump_hex(__VA_ARGS__)
78 # define dump_raw_in(...) ((void)0)
82 # define dbg(...) fprintf(stderr, __VA_ARGS__)
84 # define dbg(...) ((void)0)
88 # define dbg_der(...) fprintf(stderr, __VA_ARGS__)
90 # define dbg_der(...) ((void)0)
98 #define RECORD_TYPE_CHANGE_CIPHER_SPEC 20 /* 0x14 */
99 #define RECORD_TYPE_ALERT 21 /* 0x15 */
100 #define RECORD_TYPE_HANDSHAKE 22 /* 0x16 */
101 #define RECORD_TYPE_APPLICATION_DATA 23 /* 0x17 */
103 #define HANDSHAKE_HELLO_REQUEST 0 /* 0x00 */
104 #define HANDSHAKE_CLIENT_HELLO 1 /* 0x01 */
105 #define HANDSHAKE_SERVER_HELLO 2 /* 0x02 */
106 #define HANDSHAKE_HELLO_VERIFY_REQUEST 3 /* 0x03 */
107 #define HANDSHAKE_NEW_SESSION_TICKET 4 /* 0x04 */
108 #define HANDSHAKE_CERTIFICATE 11 /* 0x0b */
109 #define HANDSHAKE_SERVER_KEY_EXCHANGE 12 /* 0x0c */
110 #define HANDSHAKE_CERTIFICATE_REQUEST 13 /* 0x0d */
111 #define HANDSHAKE_SERVER_HELLO_DONE 14 /* 0x0e */
112 #define HANDSHAKE_CERTIFICATE_VERIFY 15 /* 0x0f */
113 #define HANDSHAKE_CLIENT_KEY_EXCHANGE 16 /* 0x10 */
114 #define HANDSHAKE_FINISHED 20 /* 0x14 */
116 #define TLS_EMPTY_RENEGOTIATION_INFO_SCSV 0x00FF /* not a real cipher id... */
118 #define SSL_NULL_WITH_NULL_NULL 0x0000
119 #define SSL_RSA_WITH_NULL_MD5 0x0001
120 #define SSL_RSA_WITH_NULL_SHA 0x0002
121 #define SSL_RSA_WITH_RC4_128_MD5 0x0004
122 #define SSL_RSA_WITH_RC4_128_SHA 0x0005
123 #define TLS_RSA_WITH_IDEA_CBC_SHA 0x0007 /* 7 */
124 #define SSL_RSA_WITH_3DES_EDE_CBC_SHA 0x000A /* 10 */
126 #define SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA 0x0016 /* 22 */
127 #define SSL_DH_anon_WITH_RC4_128_MD5 0x0018 /* 24 */
128 #define SSL_DH_anon_WITH_3DES_EDE_CBC_SHA 0x001B /* 27 */
129 #define TLS_RSA_WITH_AES_128_CBC_SHA 0x002F /*SSLv3 Kx=RSA Au=RSA Enc=AES(128) Mac=SHA1 */
130 #define TLS_DHE_RSA_WITH_AES_128_CBC_SHA 0x0033 /* 51 */
131 #define TLS_DH_anon_WITH_AES_128_CBC_SHA 0x0034 /* 52 */
132 #define TLS_RSA_WITH_AES_256_CBC_SHA 0x0035 /* 53 */
133 #define TLS_DHE_RSA_WITH_AES_256_CBC_SHA 0x0039 /* 57 */
134 #define TLS_DH_anon_WITH_AES_256_CBC_SHA 0x003A /* 58 */
135 #define TLS_RSA_WITH_NULL_SHA256 0x003B /* 59 */
136 #define TLS_RSA_WITH_AES_128_CBC_SHA256 0x003C /* 60 */
137 #define TLS_RSA_WITH_AES_256_CBC_SHA256 0x003D /* 61 */
138 #define TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 0x0067 /* 103 */
139 #define TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 0x006B /* 107 */
140 #define TLS_PSK_WITH_AES_128_CBC_SHA 0x008C /* 140 */
141 #define TLS_PSK_WITH_AES_256_CBC_SHA 0x008D /* 141 */
142 #define TLS_DHE_PSK_WITH_AES_128_CBC_SHA 0x0090 /* 144 */
143 #define TLS_DHE_PSK_WITH_AES_256_CBC_SHA 0x0091 /* 145 */
144 #define TLS_RSA_WITH_SEED_CBC_SHA 0x0096 /* 150 */
145 #define TLS_RSA_WITH_AES_128_GCM_SHA256 0x009C /*TLSv1.2 Kx=RSA Au=RSA Enc=AESGCM(128) Mac=AEAD */
146 #define TLS_RSA_WITH_AES_256_GCM_SHA384 0x009D /*TLSv1.2 Kx=RSA Au=RSA Enc=AESGCM(256) Mac=AEAD */
147 #define TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 0x009E /*TLSv1.2 Kx=DH Au=RSA Enc=AESGCM(128) Mac=AEAD */
148 #define TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 0x009F /*TLSv1.2 Kx=DH Au=RSA Enc=AESGCM(256) Mac=AEAD */
149 #define TLS_DH_anon_WITH_AES_128_GCM_SHA256 0x00A6 /* RFC 5288 */
150 #define TLS_DH_anon_WITH_AES_256_GCM_SHA384 0x00A7 /* RFC 5288 */
151 #define TLS_PSK_WITH_AES_128_CBC_SHA256 0x00AE /* 174 */
152 #define TLS_PSK_WITH_AES_256_CBC_SHA384 0x00AF /* 175 */
153 #define TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA 0xC004 /* 49156 */
154 #define TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA 0xC005 /* 49157 */
155 #define TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA 0xC009 /*TLSv1 Kx=ECDH Au=ECDSA Enc=AES(128) Mac=SHA1 */
156 #define TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA 0xC00A /*TLSv1 Kx=ECDH Au=ECDSA Enc=AES(256) Mac=SHA1 */
157 #define TLS_ECDH_RSA_WITH_AES_128_CBC_SHA 0xC00E /* 49166 */
158 #define TLS_ECDH_RSA_WITH_AES_256_CBC_SHA 0xC00F /* 49167 */
159 #define TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA 0xC012 /* 49170 */
160 #define TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA 0xC013 /*TLSv1 Kx=ECDH Au=RSA Enc=AES(128) Mac=SHA1 */
161 #define TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA 0xC014 /*TLSv1 Kx=ECDH Au=RSA Enc=AES(256) Mac=SHA1 */
162 #define TLS_ECDH_anon_WITH_AES_128_CBC_SHA 0xC018 /* RFC 4492 */
163 #define TLS_ECDH_anon_WITH_AES_256_CBC_SHA 0xC019 /* RFC 4492 */
164 #define TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 0xC023 /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AES(128) Mac=SHA256 */
165 #define TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 0xC024 /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AES(256) Mac=SHA384 */
166 #define TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 0xC025 /* 49189 */
167 #define TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 0xC026 /* 49190 */
168 #define TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 0xC027 /*TLSv1.2 Kx=ECDH Au=RSA Enc=AES(128) Mac=SHA256 */
169 #define TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 0xC028 /*TLSv1.2 Kx=ECDH Au=RSA Enc=AES(256) Mac=SHA384 */
170 #define TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 0xC029 /* 49193 */
171 #define TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 0xC02A /* 49194 */
172 /* RFC 5288 "AES Galois Counter Mode (GCM) Cipher Suites for TLS" */
173 #define TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 0xC02B /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESGCM(128) Mac=AEAD */
174 #define TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 0xC02C /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESGCM(256) Mac=AEAD */
175 #define TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 0xC02D /* 49197 */
176 #define TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 0xC02E /* 49198 */
177 #define TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 0xC02F /*TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(128) Mac=AEAD */
178 #define TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 0xC030 /*TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(256) Mac=AEAD */
179 #define TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 0xC031 /* 49201 */
180 #define TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 0xC032 /* 49202 */
181 #define TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA 0xC035
182 #define TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA 0xC036
183 #define TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256 0xC037
184 #define TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384 0xC038
186 /* From http://wiki.mozilla.org/Security/Server_Side_TLS */
187 /* and 'openssl ciphers -V -stdname' */
188 #define TLS_RSA_WITH_AES_128_CCM 0xC09C /*TLSv1.2 Kx=RSA Au=RSA Enc=AESCCM(128) Mac=AEAD */
189 #define TLS_RSA_WITH_AES_256_CCM 0xC09D /*TLSv1.2 Kx=RSA Au=RSA Enc=AESCCM(256) Mac=AEAD */
190 #define TLS_DHE_RSA_WITH_AES_128_CCM 0xC09E /*TLSv1.2 Kx=DH Au=RSA Enc=AESCCM(128) Mac=AEAD */
191 #define TLS_DHE_RSA_WITH_AES_256_CCM 0xC09F /*TLSv1.2 Kx=DH Au=RSA Enc=AESCCM(256) Mac=AEAD */
192 #define TLS_RSA_WITH_AES_128_CCM_8 0xC0A0 /*TLSv1.2 Kx=RSA Au=RSA Enc=AESCCM8(128) Mac=AEAD */
193 #define TLS_RSA_WITH_AES_256_CCM_8 0xC0A1 /*TLSv1.2 Kx=RSA Au=RSA Enc=AESCCM8(256) Mac=AEAD */
194 #define TLS_DHE_RSA_WITH_AES_128_CCM_8 0xC0A2 /*TLSv1.2 Kx=DH Au=RSA Enc=AESCCM8(128) Mac=AEAD */
195 #define TLS_DHE_RSA_WITH_AES_256_CCM_8 0xC0A3 /*TLSv1.2 Kx=DH Au=RSA Enc=AESCCM8(256) Mac=AEAD */
196 #define TLS_ECDHE_ECDSA_WITH_AES_128_CCM 0xC0AC /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESCCM(128) Mac=AEAD */
197 #define TLS_ECDHE_ECDSA_WITH_AES_256_CCM 0xC0AD /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESCCM(256) Mac=AEAD */
198 #define TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8 0xC0AE /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESCCM8(128) Mac=AEAD */
199 #define TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8 0xC0AF /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESCCM8(256) Mac=AEAD */
200 #define TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 0xCCA8 /*TLSv1.2 Kx=ECDH Au=RSA Enc=CHACHA20/POLY1305(256) Mac=AEAD */
201 #define TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 0xCCA9 /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=CHACHA20/POLY1305(256) Mac=AEAD */
202 #define TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 0xCCAA /*TLSv1.2 Kx=DH Au=RSA Enc=CHACHA20/POLY1305(256) Mac=AEAD */
204 #define TLS_AES_128_GCM_SHA256 0x1301 /*TLSv1.3 Kx=any Au=any Enc=AESGCM(128) Mac=AEAD */
205 #define TLS_AES_256_GCM_SHA384 0x1302 /*TLSv1.3 Kx=any Au=any Enc=AESGCM(256) Mac=AEAD */
206 #define TLS_CHACHA20_POLY1305_SHA256 0x1303 /*TLSv1.3 Kx=any Au=any Enc=CHACHA20/POLY1305(256) Mac=AEAD */
207 #define TLS_AES_128_CCM_SHA256 0x1304 /*TLSv1.3 Kx=any Au=any Enc=AESCCM(128) Mac=AEAD */
209 /* Might go to libbb.h */
210 #define TLS_MAX_CRYPTBLOCK_SIZE 16
211 #define TLS_MAX_OUTBUF (1 << 14)
221 RSA_PREMASTER_SIZE = 48,
225 /* 8 = 3+5. 3 extra bytes result in record data being 32-bit aligned */
226 OUTBUF_PFX = 8 + AES_BLOCK_SIZE, /* header + IV */
227 OUTBUF_SFX = TLS_MAX_MAC_SIZE + TLS_MAX_CRYPTBLOCK_SIZE, /* MAC + padding */
230 // | 6.2.1. Fragmentation
231 // | The record layer fragments information blocks into TLSPlaintext
232 // | records carrying data in chunks of 2^14 bytes or less. Client
233 // | message boundaries are not preserved in the record layer (i.e.,
234 // | multiple client messages of the same ContentType MAY be coalesced
235 // | into a single TLSPlaintext record, or a single message MAY be
236 // | fragmented across several records)
239 // | The length (in bytes) of the following TLSPlaintext.fragment.
240 // | The length MUST NOT exceed 2^14.
242 // | 6.2.2. Record Compression and Decompression
244 // | Compression must be lossless and may not increase the content length
245 // | by more than 1024 bytes. If the decompression function encounters a
246 // | TLSCompressed.fragment that would decompress to a length in excess of
247 // | 2^14 bytes, it MUST report a fatal decompression failure error.
250 // | The length (in bytes) of the following TLSCompressed.fragment.
251 // | The length MUST NOT exceed 2^14 + 1024.
253 // | 6.2.3. Record Payload Protection
254 // | The encryption and MAC functions translate a TLSCompressed
255 // | structure into a TLSCiphertext. The decryption functions reverse
256 // | the process. The MAC of the record also includes a sequence
257 // | number so that missing, extra, or repeated messages are
261 // | The length (in bytes) of the following TLSCiphertext.fragment.
262 // | The length MUST NOT exceed 2^14 + 2048.
263 MAX_INBUF = RECHDR_LEN + (1 << 14) + 2048,
265 /* Bits for tls->flags */
266 NEED_EC_KEY = 1 << 0,
267 GOT_CERT_RSA_KEY_ALG = 1 << 1,
268 GOT_CERT_ECDSA_KEY_ALG = 1 << 2, // so far unused
270 ENCRYPTION_AESGCM = 1 << 4, // else AES-SHA (or NULL-SHA if ALLOW_RSA_NULL_SHA256=1)
271 ENCRYPT_ON_WRITE = 1 << 5,
276 uint8_t proto_maj, proto_min;
277 uint8_t len16_hi, len16_lo;
280 struct tls_handshake_data {
281 /* In bbox, md5/sha1/sha256 ctx's are the same structure */
282 md5sha_ctx_t handshake_hash_ctx;
284 uint8_t client_and_server_rand32[2 * 32];
285 uint8_t master_secret[48];
287 //TODO: store just the DER key here, parse/use/delete it when sending client key
288 //this way it will stay key type agnostic here.
289 psRsaKey_t server_rsa_pub_key;
290 uint8_t ecc_pub_key32[32];
292 /* HANDSHAKE HASH: */
293 //unsigned saved_client_hello_size;
294 //uint8_t saved_client_hello[1];
298 static unsigned get24be(const uint8_t *p)
300 return 0x100*(0x100*p[0] + p[1]) + p[2];
304 /* Nondestructively see the current hash value */
306 static unsigned sha_peek(md5sha_ctx_t *ctx, void *buffer)
308 md5sha_ctx_t ctx_copy = *ctx; /* struct copy */
309 return sha_end(&ctx_copy, buffer);
313 static void dump_hex(const char *fmt, const void *vp, int len)
315 char hexbuf[32 * 1024 + 4];
316 const uint8_t *p = vp;
318 bin2hex(hexbuf, (void*)p, len)[0] = '\0';
322 static void dump_tls_record(const void *vp, int len)
324 const uint8_t *p = vp;
328 if (len < RECHDR_LEN) {
329 dump_hex("< |%s|\n", p, len);
332 xhdr_len = 0x100*p[3] + p[4];
333 dbg("< hdr_type:%u ver:%u.%u len:%u", p[0], p[1], p[2], xhdr_len);
336 if (len >= 4 && p[-RECHDR_LEN] == RECORD_TYPE_HANDSHAKE) {
337 unsigned len24 = get24be(p + 1);
338 dbg(" type:%u len24:%u", p[0], len24);
342 dump_hex(" |%s|\n", p, xhdr_len);
348 # define dump_hex(...) ((void)0)
349 # define dump_tls_record(...) ((void)0)
352 void FAST_FUNC tls_get_random(void *buf, unsigned len)
354 if (len != open_read_close("/dev/urandom", buf, len))
358 static void xorbuf3(void *dst, const void *src1, const void *src2, unsigned count)
361 const uint8_t *s1 = src1;
362 const uint8_t* s2 = src2;
364 *d++ = *s1++ ^ *s2++;
367 void FAST_FUNC xorbuf(void *dst, const void *src, unsigned count)
369 xorbuf3(dst, dst, src, count);
372 void FAST_FUNC xorbuf_aligned_AES_BLOCK_SIZE(void *dst, const void *src)
374 unsigned long *d = dst;
375 const unsigned long *s = src;
377 #if ULONG_MAX <= 0xffffffffffffffff
379 #if ULONG_MAX == 0xffffffff
387 # define hash_handshake(tls, fmt, buffer, len) \
388 hash_handshake(tls, buffer, len)
390 static void hash_handshake(tls_state_t *tls, const char *fmt, const void *buffer, unsigned len)
392 md5sha_hash(&tls->hsd->handshake_hash_ctx, buffer, len);
395 uint8_t h[TLS_MAX_MAC_SIZE];
396 dump_hex(fmt, buffer, len);
397 dbg(" (%u bytes) ", (int)len);
398 len = sha_peek(&tls->hsd->handshake_hash_ctx, h);
399 if (ENABLE_FEATURE_TLS_SHA1 && len == SHA1_OUTSIZE)
400 dump_hex("sha1:%s\n", h, len);
402 if (len == SHA256_OUTSIZE)
403 dump_hex("sha256:%s\n", h, len);
405 dump_hex("sha???:%s\n", h, len);
410 #if !ENABLE_FEATURE_TLS_SHA1
411 # define TLS_MAC_SIZE(tls) SHA256_OUTSIZE
413 # define TLS_MAC_SIZE(tls) (tls)->MAC_size
417 // HMAC(key, text) based on a hash H (say, sha256) is:
418 // ipad = [0x36 x INSIZE]
419 // opad = [0x5c x INSIZE]
420 // HMAC(key, text) = H((key XOR opad) + H((key XOR ipad) + text))
422 // H(key XOR opad) and H(key XOR ipad) can be precomputed
423 // if we often need HMAC hmac with the same key.
425 // text is often given in disjoint pieces.
426 typedef struct hmac_precomputed {
427 md5sha_ctx_t hashed_key_xor_ipad;
428 md5sha_ctx_t hashed_key_xor_opad;
429 } hmac_precomputed_t;
431 typedef void md5sha_begin_func(md5sha_ctx_t *ctx) FAST_FUNC;
432 #if !ENABLE_FEATURE_TLS_SHA1
433 #define hmac_begin(pre,key,key_size,begin) \
434 hmac_begin(pre,key,key_size)
435 #define begin sha256_begin
437 static void hmac_begin(hmac_precomputed_t *pre, uint8_t *key, unsigned key_size, md5sha_begin_func *begin)
439 uint8_t key_xor_ipad[SHA_INSIZE];
440 uint8_t key_xor_opad[SHA_INSIZE];
441 // uint8_t tempkey[SHA1_OUTSIZE < SHA256_OUTSIZE ? SHA256_OUTSIZE : SHA1_OUTSIZE];
444 // "The authentication key can be of any length up to INSIZE, the
445 // block length of the hash function. Applications that use keys longer
446 // than INSIZE bytes will first hash the key using H and then use the
447 // resultant OUTSIZE byte string as the actual key to HMAC."
448 if (key_size > SHA_INSIZE) {
449 bb_simple_error_msg_and_die("HMAC key>64"); //does not happen (yet?)
452 // md5sha_hash(&ctx, key, key_size);
453 // key_size = sha_end(&ctx, tempkey);
454 // //key = tempkey; - right? RIGHT? why does it work without this?
455 // // because SHA_INSIZE is 64, but hmac() is always called with
456 // // key_size = tls->MAC_size = SHA1/256_OUTSIZE (20 or 32),
457 // // and prf_hmac_sha256() -> hmac_sha256() key sizes are:
458 // // - RSA_PREMASTER_SIZE is 48
459 // // - CURVE25519_KEYSIZE is 32
460 // // - master_secret[] is 48
463 for (i = 0; i < key_size; i++) {
464 key_xor_ipad[i] = key[i] ^ 0x36;
465 key_xor_opad[i] = key[i] ^ 0x5c;
467 for (; i < SHA_INSIZE; i++) {
468 key_xor_ipad[i] = 0x36;
469 key_xor_opad[i] = 0x5c;
472 begin(&pre->hashed_key_xor_ipad);
473 begin(&pre->hashed_key_xor_opad);
474 md5sha_hash(&pre->hashed_key_xor_ipad, key_xor_ipad, SHA_INSIZE);
475 md5sha_hash(&pre->hashed_key_xor_opad, key_xor_opad, SHA_INSIZE);
479 static unsigned hmac_sha_precomputed_v(
480 hmac_precomputed_t *pre,
487 /* pre->hashed_key_xor_ipad contains unclosed "H((key XOR ipad) +" state */
488 /* pre->hashed_key_xor_opad contains unclosed "H((key XOR opad) +" state */
490 /* calculate out = H((key XOR ipad) + text) */
491 while ((text = va_arg(va, uint8_t*)) != NULL) {
492 unsigned text_size = va_arg(va, unsigned);
493 md5sha_hash(&pre->hashed_key_xor_ipad, text, text_size);
495 len = sha_end(&pre->hashed_key_xor_ipad, out);
497 /* out = H((key XOR opad) + out) */
498 md5sha_hash(&pre->hashed_key_xor_opad, out, len);
499 return sha_end(&pre->hashed_key_xor_opad, out);
502 static unsigned hmac_sha_precomputed(hmac_precomputed_t *pre_init, uint8_t *out, ...)
504 hmac_precomputed_t pre;
509 pre = *pre_init; /* struct copy */
510 len = hmac_sha_precomputed_v(&pre, out, va);
515 #if !ENABLE_FEATURE_TLS_SHA1
516 #define hmac(tls,out,key,key_size,...) \
517 hmac(out,key,key_size, __VA_ARGS__)
519 static unsigned hmac(tls_state_t *tls, uint8_t *out, uint8_t *key, unsigned key_size, ...)
521 hmac_precomputed_t pre;
525 va_start(va, key_size);
527 hmac_begin(&pre, key, key_size,
528 (ENABLE_FEATURE_TLS_SHA1 && tls->MAC_size == SHA1_OUTSIZE)
532 len = hmac_sha_precomputed_v(&pre, out, va);
539 // 5. HMAC and the Pseudorandom Function
541 // In this section, we define one PRF, based on HMAC. This PRF with the
542 // SHA-256 hash function is used for all cipher suites defined in this
543 // document and in TLS documents published prior to this document when
544 // TLS 1.2 is negotiated.
545 // ^^^^^^^^^^^^^ IMPORTANT!
546 // PRF uses sha256 regardless of cipher for all ciphers
547 // defined by RFC 5246. It's not sha1 for AES_128_CBC_SHA!
548 // However, for _SHA384 ciphers, it's sha384. See RFC 5288,5289.
550 // P_hash(secret, seed) = HMAC_hash(secret, A(1) + seed) +
551 // HMAC_hash(secret, A(2) + seed) +
552 // HMAC_hash(secret, A(3) + seed) + ...
553 // where + indicates concatenation.
554 // A() is defined as:
556 // A(1) = HMAC_hash(secret, A(0)) = HMAC_hash(secret, seed)
557 // A(i) = HMAC_hash(secret, A(i-1))
558 // P_hash can be iterated as many times as necessary to produce the
559 // required quantity of data. For example, if P_SHA256 is being used to
560 // create 80 bytes of data, it will have to be iterated three times
561 // (through A(3)), creating 96 bytes of output data; the last 16 bytes
562 // of the final iteration will then be discarded, leaving 80 bytes of
565 // TLS's PRF is created by applying P_hash to the secret as:
567 // PRF(secret, label, seed) = P_<hash>(secret, label + seed)
569 // The label is an ASCII string.
572 // For cipher suites ending with _SHA256, the PRF is the TLS PRF
573 // with SHA-256 as the hash function.
574 // For cipher suites ending with _SHA384, the PRF is the TLS PRF
575 // with SHA-384 as the hash function.
576 static void prf_hmac_sha256(/*tls_state_t *tls,*/
577 uint8_t *outbuf, unsigned outbuf_size,
578 uint8_t *secret, unsigned secret_size,
580 uint8_t *seed, unsigned seed_size)
582 hmac_precomputed_t pre;
583 uint8_t a[TLS_MAX_MAC_SIZE];
584 uint8_t *out_p = outbuf;
585 unsigned label_size = strlen(label);
586 unsigned MAC_size = SHA256_OUTSIZE;
588 /* In P_hash() calculation, "seed" is "label + seed": */
589 #define SEED label, label_size, seed, seed_size
590 #define A a, MAC_size
592 hmac_begin(&pre, secret, secret_size, sha256_begin);
594 /* A(1) = HMAC_hash(secret, seed) */
595 hmac_sha_precomputed(&pre, a, SEED, NULL);
598 /* HMAC_hash(secret, A(1) + seed) */
599 if (outbuf_size <= MAC_size) {
600 /* Last, possibly incomplete, block */
601 /* (use a[] as temp buffer) */
602 hmac_sha_precomputed(&pre, a, A, SEED, NULL);
603 memcpy(out_p, a, outbuf_size);
606 /* Not last block. Store directly to result buffer */
607 hmac_sha_precomputed(&pre, out_p, A, SEED, NULL);
609 outbuf_size -= MAC_size;
610 /* A(2) = HMAC_hash(secret, A(1)) */
611 hmac_sha_precomputed(&pre, a, A, NULL);
618 static void bad_record_die(tls_state_t *tls, const char *expected, int len)
620 bb_error_msg("got bad TLS record (len:%d) while expecting %s", len, expected);
622 uint8_t *p = tls->inbuf;
624 len = 99; /* don't flood, a few lines should be enough */
626 fprintf(stderr, " %02x", *p++);
634 static void tls_error_die(tls_state_t *tls, int line)
636 dump_tls_record(tls->inbuf, tls->ofs_to_buffered + tls->buffered_size);
637 bb_error_msg_and_die("tls error at line %d cipher:%04x", line, tls->cipher_id);
639 #define tls_error_die(tls) tls_error_die(tls, __LINE__)
642 static void tls_free_inbuf(tls_state_t *tls)
644 if (tls->buffered_size == 0) {
652 static void tls_free_outbuf(tls_state_t *tls)
655 tls->outbuf_size = 0;
659 static void *tls_get_outbuf(tls_state_t *tls, int len)
661 if (len > TLS_MAX_OUTBUF)
663 len += OUTBUF_PFX + OUTBUF_SFX;
664 if (tls->outbuf_size < len) {
665 tls->outbuf_size = len;
666 tls->outbuf = xrealloc(tls->outbuf, len);
668 return tls->outbuf + OUTBUF_PFX;
671 static void *tls_get_zeroed_outbuf(tls_state_t *tls, int len)
673 void *record = tls_get_outbuf(tls, len);
674 memset(record, 0, len);
678 static void xwrite_encrypted_and_hmac_signed(tls_state_t *tls, unsigned size, unsigned type)
680 uint8_t *buf = tls->outbuf + OUTBUF_PFX;
681 struct record_hdr *xhdr;
682 uint8_t padding_length;
684 xhdr = (void*)(buf - RECHDR_LEN);
685 if (!ALLOW_RSA_NULL_SHA256 /* if "no encryption" can't be selected */
686 || tls->cipher_id != TLS_RSA_WITH_NULL_SHA256 /* or if it wasn't selected */
688 xhdr = (void*)(buf - RECHDR_LEN - AES_BLOCK_SIZE); /* place for IV */
692 xhdr->proto_maj = TLS_MAJ;
693 xhdr->proto_min = TLS_MIN;
694 /* fake unencrypted record len for MAC calculation */
695 xhdr->len16_hi = size >> 8;
696 xhdr->len16_lo = size & 0xff;
698 /* Calculate MAC signature */
699 hmac(tls, buf + size, /* result */
700 tls->client_write_MAC_key, TLS_MAC_SIZE(tls),
701 &tls->write_seq64_be, sizeof(tls->write_seq64_be),
706 tls->write_seq64_be = SWAP_BE64(1 + SWAP_BE64(tls->write_seq64_be));
708 size += TLS_MAC_SIZE(tls);
711 // 6.2.3.1. Null or Standard Stream Cipher
713 // Stream ciphers (including BulkCipherAlgorithm.null; see Appendix A.6)
714 // convert TLSCompressed.fragment structures to and from stream
715 // TLSCiphertext.fragment structures.
717 // stream-ciphered struct {
718 // opaque content[TLSCompressed.length];
719 // opaque MAC[SecurityParameters.mac_length];
720 // } GenericStreamCipher;
722 // The MAC is generated as:
723 // MAC(MAC_write_key, seq_num +
724 // TLSCompressed.type +
725 // TLSCompressed.version +
726 // TLSCompressed.length +
727 // TLSCompressed.fragment);
728 // where "+" denotes concatenation.
730 // The sequence number for this record.
732 // The MAC algorithm specified by SecurityParameters.mac_algorithm.
734 // Note that the MAC is computed before encryption. The stream cipher
735 // encrypts the entire block, including the MAC.
737 // Appendix C. Cipher Suite Definitions
739 // MAC Algorithm mac_length mac_key_length
740 // -------- ----------- ---------- --------------
741 // SHA HMAC-SHA1 20 20
742 // SHA256 HMAC-SHA256 32 32
743 if (ALLOW_RSA_NULL_SHA256
744 && tls->cipher_id == TLS_RSA_WITH_NULL_SHA256
746 /* No encryption, only signing */
747 xhdr->len16_hi = size >> 8;
748 xhdr->len16_lo = size & 0xff;
749 dump_raw_out(">> %s\n", xhdr, RECHDR_LEN + size);
750 xwrite(tls->ofd, xhdr, RECHDR_LEN + size);
751 dbg("wrote %u bytes (NULL crypt, SHA256 hash)\n", size);
755 // 6.2.3.2. CBC Block Cipher
756 // For block ciphers (such as 3DES or AES), the encryption and MAC
757 // functions convert TLSCompressed.fragment structures to and from block
758 // TLSCiphertext.fragment structures.
760 // opaque IV[SecurityParameters.record_iv_length];
761 // block-ciphered struct {
762 // opaque content[TLSCompressed.length];
763 // opaque MAC[SecurityParameters.mac_length];
764 // uint8 padding[GenericBlockCipher.padding_length];
765 // uint8 padding_length;
767 // } GenericBlockCipher;
770 // The Initialization Vector (IV) SHOULD be chosen at random, and
771 // MUST be unpredictable. Note that in versions of TLS prior to 1.1,
772 // there was no IV field (...). For block ciphers, the IV length is
773 // of length SecurityParameters.record_iv_length, which is equal to the
774 // SecurityParameters.block_size.
776 // Padding that is added to force the length of the plaintext to be
777 // an integral multiple of the block cipher's block length.
779 // The padding length MUST be such that the total size of the
780 // GenericBlockCipher structure is a multiple of the cipher's block
781 // length. Legal values range from zero to 255, inclusive.
783 // Appendix C. Cipher Suite Definitions
786 // Cipher Type Material Size Size
787 // ------------ ------ -------- ---- -----
788 // AES_128_CBC Block 16 16 16
789 // AES_256_CBC Block 32 16 16
791 tls_get_random(buf - AES_BLOCK_SIZE, AES_BLOCK_SIZE); /* IV */
792 dbg("before crypt: 5 hdr + %u data + %u hash bytes\n",
793 size - TLS_MAC_SIZE(tls), TLS_MAC_SIZE(tls));
795 /* Fill IV and padding in outbuf */
796 // RFC is talking nonsense:
797 // "Padding that is added to force the length of the plaintext to be
798 // an integral multiple of the block cipher's block length."
799 // WRONG. _padding+padding_length_, not just _padding_,
801 // IOW: padding_length is the last byte of padding[] array,
802 // contrary to what RFC depicts.
804 // What actually happens is that there is always padding.
805 // If you need one byte to reach BLOCKSIZE, this byte is 0x00.
806 // If you need two bytes, they are both 0x01.
807 // If you need three, they are 0x02,0x02,0x02. And so on.
808 // If you need no bytes to reach BLOCKSIZE, you have to pad a full
809 // BLOCKSIZE with bytes of value (BLOCKSIZE-1).
810 // It's ok to have more than minimum padding, but we do minimum.
811 padding_length = (~size) & (AES_BLOCK_SIZE - 1);
813 buf[size++] = padding_length; /* padding */
814 } while ((size & (AES_BLOCK_SIZE - 1)) != 0);
816 /* Encrypt content+MAC+padding in place */
818 &tls->aes_encrypt, /* selects 128/256 */
819 buf - AES_BLOCK_SIZE, /* IV */
820 buf, size, /* plaintext */
825 dbg("writing 5 + %u IV + %u encrypted bytes, padding_length:0x%02x\n",
826 AES_BLOCK_SIZE, size, padding_length);
827 size += AES_BLOCK_SIZE; /* + IV */
828 xhdr->len16_hi = size >> 8;
829 xhdr->len16_lo = size & 0xff;
830 dump_raw_out(">> %s\n", xhdr, RECHDR_LEN + size);
831 xwrite(tls->ofd, xhdr, RECHDR_LEN + size);
832 dbg("wrote %u bytes\n", (int)RECHDR_LEN + size);
835 /* Example how GCM encryption combines nonce, aad, input and generates
836 * "header | exp_nonce | encrypted output | tag":
837 * nonce:0d 6a 26 31 00 00 00 00 00 00 00 01 (implicit 4 bytes (derived from master secret), then explicit 8 bytes)
838 * aad: 00 00 00 00 00 00 00 01 17 03 03 00 1c
839 * in: 47 45 54 20 2f 69 6e 64 65 78 2e 68 74 6d 6c 20 48 54 54 50 2f 31 2e 30 0d 0a 0d 0a "GET /index.html HTTP/1.0\r\n\r\n" (0x1c bytes)
840 * out: f7 8a b2 8f 78 0e f6 d5 76 17 2e b5 6d 46 59 56 8b 46 9f 0b d9 2c 35 28 13 66 19 be
841 * tag: c2 86 ce 4a 50 4a d0 aa 50 b3 76 5c 49 2a 3f 33
842 * sent: 17 03 03 00 34|00 00 00 00 00 00 00 01|f7 8a b2 8f 78 0e f6 d5 76 17 2e b5 6d 46 59 56 8b 46 9f 0b d9 2c 35 28 13 66 19 be|c2 86 ce 4a 50 4a d0 aa 50 b3 76 5c 49 2a 3f 33
843 * .............................................^^ buf points here
845 static void xwrite_encrypted_aesgcm(tls_state_t *tls, unsigned size, unsigned type)
847 #define COUNTER(v) (*(uint32_t*)(v + 12))
849 uint8_t aad[13 + 3] ALIGNED_long; /* +3 creates [16] buffer, simplifying GHASH() */
850 uint8_t nonce[12 + 4] ALIGNED_long; /* +4 creates space for AES block counter */
851 uint8_t scratch[AES_BLOCK_SIZE] ALIGNED_long; //[16]
852 uint8_t authtag[AES_BLOCK_SIZE] ALIGNED_long; //[16]
854 struct record_hdr *xhdr;
859 buf = tls->outbuf + OUTBUF_PFX; /* see above for the byte it points to */
860 dump_hex("xwrite_encrypted_aesgcm plaintext:%s\n", buf, size);
862 xhdr = (void*)(buf - 8 - RECHDR_LEN);
863 xhdr->type = type; /* do it here so that "type" param no longer used */
869 /* set aad[12], and clear aad[13..15] */
870 COUNTER(aad) = SWAP_LE32(size & 0xff);
872 memcpy(nonce, tls->client_write_IV, 4);
873 t64 = tls->write_seq64_be;
874 move_to_unaligned64(nonce + 4, t64);
875 move_to_unaligned64(aad, t64);
876 move_to_unaligned64(buf - 8, t64);
877 /* seq64 is not used later in this func, can increment here */
878 tls->write_seq64_be = SWAP_BE64(1 + SWAP_BE64(t64));
882 while (remaining != 0) {
886 COUNTER(nonce) = htonl(cnt); /* yes, first cnt here is 2 (!) */
887 aes_encrypt_one_block(&tls->aes_encrypt, nonce, scratch);
888 n = remaining > AES_BLOCK_SIZE ? AES_BLOCK_SIZE : remaining;
889 xorbuf(buf, scratch, n);
894 aesgcm_GHASH(tls->H, aad, /*sizeof(aad),*/ tls->outbuf + OUTBUF_PFX, size, authtag /*, sizeof(authtag)*/);
895 COUNTER(nonce) = htonl(1);
896 aes_encrypt_one_block(&tls->aes_encrypt, nonce, scratch);
897 xorbuf_aligned_AES_BLOCK_SIZE(authtag, scratch);
899 memcpy(buf, authtag, sizeof(authtag));
902 xhdr = (void*)(tls->outbuf + OUTBUF_PFX - 8 - RECHDR_LEN);
903 size += 8 + sizeof(authtag);
904 /*xhdr->type = type; - already is */
905 xhdr->proto_maj = TLS_MAJ;
906 xhdr->proto_min = TLS_MIN;
907 xhdr->len16_hi = size >> 8;
908 xhdr->len16_lo = size & 0xff;
910 dump_raw_out(">> %s\n", xhdr, size);
911 xwrite(tls->ofd, xhdr, size);
912 dbg("wrote %u bytes\n", size);
916 static void xwrite_encrypted(tls_state_t *tls, unsigned size, unsigned type)
918 if (!(tls->flags & ENCRYPTION_AESGCM)) {
919 xwrite_encrypted_and_hmac_signed(tls, size, type);
922 xwrite_encrypted_aesgcm(tls, size, type);
925 static void xwrite_handshake_record(tls_state_t *tls, unsigned size)
927 uint8_t *buf = tls->outbuf + OUTBUF_PFX;
928 struct record_hdr *xhdr = (void*)(buf - RECHDR_LEN);
930 xhdr->type = RECORD_TYPE_HANDSHAKE;
931 xhdr->proto_maj = TLS_MAJ;
932 xhdr->proto_min = TLS_MIN;
933 xhdr->len16_hi = size >> 8;
934 xhdr->len16_lo = size & 0xff;
935 dump_raw_out(">> %s\n", xhdr, RECHDR_LEN + size);
936 xwrite(tls->ofd, xhdr, RECHDR_LEN + size);
937 dbg("wrote %u bytes\n", (int)RECHDR_LEN + size);
940 static void xwrite_and_update_handshake_hash(tls_state_t *tls, unsigned size)
942 if (!(tls->flags & ENCRYPT_ON_WRITE)) {
945 xwrite_handshake_record(tls, size);
946 /* Handshake hash does not include record headers */
947 buf = tls->outbuf + OUTBUF_PFX;
948 hash_handshake(tls, ">> hash:%s", buf, size);
951 xwrite_encrypted(tls, size, RECORD_TYPE_HANDSHAKE);
954 static int tls_has_buffered_record(tls_state_t *tls)
956 int buffered = tls->buffered_size;
957 struct record_hdr *xhdr;
960 if (buffered < RECHDR_LEN)
962 xhdr = (void*)(tls->inbuf + tls->ofs_to_buffered);
963 rec_size = RECHDR_LEN + (0x100 * xhdr->len16_hi + xhdr->len16_lo);
964 if (buffered < rec_size)
969 static const char *alert_text(int code)
972 case 20: return "bad MAC";
973 case 50: return "decode error";
974 case 51: return "decrypt error";
975 case 40: return "handshake failure";
976 case 112: return "unrecognized name";
981 static void tls_aesgcm_decrypt(tls_state_t *tls, uint8_t *buf, int size)
983 #define COUNTER(v) (*(uint32_t*)(v + 12))
985 //uint8_t aad[13 + 3] ALIGNED_long; /* +3 creates [16] buffer, simplifying GHASH() */
986 uint8_t nonce[12 + 4] ALIGNED_long; /* +4 creates space for AES block counter */
987 uint8_t scratch[AES_BLOCK_SIZE] ALIGNED_long; //[16]
988 //uint8_t authtag[AES_BLOCK_SIZE] ALIGNED_long; //[16]
992 //memcpy(aad, buf, 8);
996 //aad[11] = size >> 8;
997 ///* set aad[12], and clear aad[13..15] */
998 //COUNTER(aad) = SWAP_LE32(size & 0xff);
1000 memcpy(nonce, tls->server_write_IV, 4);
1001 memcpy(nonce + 4, buf, 8);
1005 while (remaining != 0) {
1009 COUNTER(nonce) = htonl(cnt); /* yes, first cnt here is 2 (!) */
1010 aes_encrypt_one_block(&tls->aes_decrypt, nonce, scratch);
1011 n = remaining > AES_BLOCK_SIZE ? AES_BLOCK_SIZE : remaining;
1012 xorbuf3(buf, scratch, buf + 8, n);
1017 //aesgcm_GHASH(tls->H, aad, tls->inbuf + RECHDR_LEN, size, authtag);
1018 //COUNTER(nonce) = htonl(1);
1019 //aes_encrypt_one_block(&tls->aes_encrypt, nonce, scratch);
1020 //xorbuf_aligned_AES_BLOCK_SIZE(authtag, scratch);
1022 //memcmp(buf, authtag, sizeof(authtag)) || DIE("HASH DOES NOT MATCH!");
1026 static int tls_xread_record(tls_state_t *tls, const char *expected)
1028 struct record_hdr *xhdr;
1034 dbg("ofs_to_buffered:%u buffered_size:%u\n", tls->ofs_to_buffered, tls->buffered_size);
1035 total = tls->buffered_size;
1037 memmove(tls->inbuf, tls->inbuf + tls->ofs_to_buffered, total);
1038 //dbg("<< remaining at %d [%d] ", tls->ofs_to_buffered, total);
1039 //dump_raw_in("<< %s\n", tls->inbuf, total);
1046 if (total >= RECHDR_LEN && target == MAX_INBUF) {
1047 xhdr = (void*)tls->inbuf;
1048 target = RECHDR_LEN + (0x100 * xhdr->len16_hi + xhdr->len16_lo);
1050 if (target > MAX_INBUF /* malformed input (too long) */
1051 || xhdr->proto_maj != TLS_MAJ
1052 || xhdr->proto_min != TLS_MIN
1054 sz = total < target ? total : target;
1055 bad_record_die(tls, expected, sz);
1057 dbg("xhdr type:%d ver:%d.%d len:%d\n",
1058 xhdr->type, xhdr->proto_maj, xhdr->proto_min,
1059 0x100 * xhdr->len16_hi + xhdr->len16_lo
1062 /* if total >= target, we have a full packet (and possibly more)... */
1063 if (total - target >= 0)
1065 /* input buffer is grown only as needed */
1066 rem = tls->inbuf_size - total;
1068 tls->inbuf_size += MAX_INBUF / 8;
1069 if (tls->inbuf_size > MAX_INBUF)
1070 tls->inbuf_size = MAX_INBUF;
1071 dbg("inbuf_size:%d\n", tls->inbuf_size);
1072 rem = tls->inbuf_size - total;
1073 tls->inbuf = xrealloc(tls->inbuf, tls->inbuf_size);
1075 sz = safe_read(tls->ifd, tls->inbuf + total, rem);
1077 if (sz == 0 && total == 0) {
1078 /* "Abrupt" EOF, no TLS shutdown (seen from kernel.org) */
1079 dbg("EOF (without TLS shutdown) from peer\n");
1080 tls->buffered_size = 0;
1083 bb_perror_msg_and_die("short read, have only %d", total);
1085 dump_raw_in("<< %s\n", tls->inbuf + total, sz);
1088 tls->buffered_size = total - target;
1089 tls->ofs_to_buffered = target;
1090 //dbg("<< stashing at %d [%d] ", tls->ofs_to_buffered, tls->buffered_size);
1091 //dump_hex("<< %s\n", tls->inbuf + tls->ofs_to_buffered, tls->buffered_size);
1093 sz = target - RECHDR_LEN;
1095 /* Needs to be decrypted? */
1096 if (tls->min_encrypted_len_on_read != 0) {
1097 if (sz < (int)tls->min_encrypted_len_on_read)
1098 bb_error_msg_and_die("bad encrypted len:%u", sz);
1100 if (tls->flags & ENCRYPTION_AESGCM) {
1102 uint8_t *p = tls->inbuf + RECHDR_LEN;
1104 sz -= 8 + AES_BLOCK_SIZE; /* we will overwrite nonce, drop hash */
1105 tls_aesgcm_decrypt(tls, p, sz);
1106 dbg("encrypted size:%u\n", sz);
1108 if (tls->min_encrypted_len_on_read > TLS_MAC_SIZE(tls)) {
1110 uint8_t *p = tls->inbuf + RECHDR_LEN;
1113 if (sz & (AES_BLOCK_SIZE-1))
1114 bb_error_msg_and_die("bad encrypted len:%u", sz);
1116 /* Decrypt content+MAC+padding, moving it over IV in the process */
1117 sz -= AES_BLOCK_SIZE; /* we will overwrite IV now */
1119 &tls->aes_decrypt, /* selects 128/256 */
1121 p + AES_BLOCK_SIZE, sz, /* ciphertext */
1124 padding_len = p[sz - 1];
1125 dbg("encrypted size:%u type:0x%02x padding_length:0x%02x\n", sz, p[0], padding_len);
1127 sz -= TLS_MAC_SIZE(tls) + padding_len; /* drop MAC and padding */
1129 /* if nonzero, then it's TLS_RSA_WITH_NULL_SHA256: drop MAC */
1130 /* else: no encryption yet on input, subtract zero = NOP */
1131 sz -= tls->min_encrypted_len_on_read;
1135 bb_simple_error_msg_and_die("encrypted data too short");
1137 //dump_hex("<< %s\n", tls->inbuf, RECHDR_LEN + sz);
1139 xhdr = (void*)tls->inbuf;
1140 if (xhdr->type == RECORD_TYPE_ALERT && sz >= 2) {
1141 uint8_t *p = tls->inbuf + RECHDR_LEN;
1142 dbg("ALERT size:%d level:%d description:%d\n", sz, p[0], p[1]);
1143 if (p[0] == 2) { /* fatal */
1144 bb_error_msg_and_die("TLS %s from peer (alert code %d): %s",
1146 p[1], alert_text(p[1])
1149 if (p[0] == 1) { /* warning */
1150 if (p[1] == 0) { /* "close_notify" warning: it's EOF */
1151 dbg("EOF (TLS encoded) from peer\n");
1155 //This possibly needs to be cached and shown only if
1156 //a fatal alert follows
1157 // bb_error_msg("TLS %s from peer (alert code %d): %s",
1159 // p[1], alert_text(p[1])
1161 /* discard it, get next record */
1164 /* p[0] not 1 or 2: not defined in protocol */
1169 /* RFC 5246 is not saying it explicitly, but sha256 hash
1170 * in our FINISHED record must include data of incoming packets too!
1172 if (tls->inbuf[0] == RECORD_TYPE_HANDSHAKE
1173 /* HANDSHAKE HASH: */
1174 // && do_we_know_which_hash_to_use /* server_hello() might not know it in the future! */
1176 hash_handshake(tls, "<< hash:%s", tls->inbuf + RECHDR_LEN, sz);
1179 dbg("got block len:%u\n", sz);
1183 static void binary_to_pstm(pstm_int *pstm_n, uint8_t *bin_ptr, unsigned len)
1185 pstm_init_for_read_unsigned_bin(/*pool:*/ NULL, pstm_n, len);
1186 pstm_read_unsigned_bin(pstm_n, bin_ptr, len);
1187 //return bin_ptr + len;
1191 * DER parsing routines
1193 static unsigned get_der_len(uint8_t **bodyp, uint8_t *der, uint8_t *end)
1199 // if ((der[0] & 0x1f) == 0x1f) /* not single-byte item code? */
1202 len = der[1]; /* maybe it's short len */
1206 if (len == 0x80 || end - der < (int)(len - 0x7e)) {
1207 /* 0x80 is "0 bytes of len", invalid DER: must use short len if can */
1208 /* need 3 or 4 bytes for 81, 82 */
1212 len1 = der[2]; /* if (len == 0x81) it's "ii 81 xx", fetch xx */
1214 /* >0x82 is "3+ bytes of len", should not happen realistically */
1217 if (len == 0x82) { /* it's "ii 82 xx yy" */
1218 len1 = 0x100*len1 + der[3];
1219 der += 1; /* skip [yy] */
1221 der += 1; /* skip [xx] */
1224 // xfunc_die(); /* invalid DER: must use short len if can */
1226 der += 2; /* skip [code]+[1byte] */
1228 if (end - der < (int)len)
1235 static uint8_t *enter_der_item(uint8_t *der, uint8_t **endp)
1238 unsigned len = get_der_len(&new_der, der, *endp);
1239 dbg_der("entered der @%p:0x%02x len:%u inner_byte @%p:0x%02x\n", der, der[0], len, new_der, new_der[0]);
1240 /* Move "end" position to cover only this item */
1241 *endp = new_der + len;
1245 static uint8_t *skip_der_item(uint8_t *der, uint8_t *end)
1248 unsigned len = get_der_len(&new_der, der, end);
1251 dbg_der("skipped der 0x%02x, next byte 0x%02x\n", der[0], new_der[0]);
1255 static void der_binary_to_pstm(pstm_int *pstm_n, uint8_t *der, uint8_t *end)
1258 unsigned len = get_der_len(&bin_ptr, der, end);
1260 dbg_der("binary bytes:%u, first:0x%02x\n", len, bin_ptr[0]);
1261 binary_to_pstm(pstm_n, bin_ptr, len);
1264 static void find_key_in_der_cert(tls_state_t *tls, uint8_t *der, int len)
1266 /* Certificate is a DER-encoded data structure. Each DER element has a length,
1267 * which makes it easy to skip over large compound elements of any complexity
1268 * without parsing them. Example: partial decode of kernel.org certificate:
1269 * SEQ 0x05ac/1452 bytes (Certificate): 308205ac
1270 * SEQ 0x0494/1172 bytes (tbsCertificate): 30820494
1271 * [ASN_CONTEXT_SPECIFIC | ASN_CONSTRUCTED | 0] 3 bytes: a003
1272 * INTEGER (version): 0201 02
1273 * INTEGER 0x11 bytes (serialNumber): 0211 00 9f85bf664b0cddafca508679501b2be4
1274 * //^^^^^^note: matrixSSL also allows [ASN_CONTEXT_SPECIFIC | ASN_PRIMITIVE | 2] = 0x82 type
1275 * SEQ 0x0d bytes (signatureAlgo): 300d
1276 * OID 9 bytes: 0609 2a864886f70d01010b (OID_SHA256_RSA_SIG 42.134.72.134.247.13.1.1.11)
1278 * SEQ 0x5f bytes (issuer): 305f
1279 * SET 11 bytes: 310b
1281 * OID 3 bytes: 0603 550406
1282 * Printable string "FR": 1302 4652
1283 * SET 14 bytes: 310e
1284 * SEQ 12 bytes: 300c
1285 * OID 3 bytes: 0603 550408
1286 * Printable string "Paris": 1305 5061726973
1287 * SET 14 bytes: 310e
1288 * SEQ 12 bytes: 300c
1289 * OID 3 bytes: 0603 550407
1290 * Printable string "Paris": 1305 5061726973
1291 * SET 14 bytes: 310e
1292 * SEQ 12 bytes: 300c
1293 * OID 3 bytes: 0603 55040a
1294 * Printable string "Gandi": 1305 47616e6469
1295 * SET 32 bytes: 3120
1296 * SEQ 30 bytes: 301e
1297 * OID 3 bytes: 0603 550403
1298 * Printable string "Gandi Standard SSL CA 2": 1317 47616e6469205374616e646172642053534c2043412032
1299 * SEQ 30 bytes (validity): 301e
1300 * TIME "161011000000Z": 170d 3136313031313030303030305a
1301 * TIME "191011235959Z": 170d 3139313031313233353935395a
1302 * SEQ 0x5b/91 bytes (subject): 305b //I did not decode this
1303 * 3121301f060355040b1318446f6d61696e20436f
1304 * 6e74726f6c2056616c6964617465643121301f06
1305 * 0355040b1318506f73697469766553534c204d75
1306 * 6c74692d446f6d61696e31133011060355040313
1307 * 0a6b65726e656c2e6f7267
1308 * SEQ 0x01a2/418 bytes (subjectPublicKeyInfo): 308201a2
1309 * SEQ 13 bytes (algorithm): 300d
1310 * OID 9 bytes: 0609 2a864886f70d010101 (OID_RSA_KEY_ALG 42.134.72.134.247.13.1.1.1)
1312 * BITSTRING 0x018f/399 bytes (publicKey): 0382018f
1314 * //after the zero byte, it appears key itself uses DER encoding:
1315 * SEQ 0x018a/394 bytes: 3082018a
1316 * INTEGER 0x0181/385 bytes (modulus): 02820181
1317 * 00b1ab2fc727a3bef76780c9349bf3
1318 * ...24 more blocks of 15 bytes each...
1319 * 90e895291c6bc8693b65
1320 * INTEGER 3 bytes (exponent): 0203 010001
1321 * [ASN_CONTEXT_SPECIFIC | ASN_CONSTRUCTED | 0x3] 0x01e5 bytes (X509v3 extensions): a38201e5
1322 * SEQ 0x01e1 bytes: 308201e1
1324 * Certificate is a sequence of three elements:
1325 * tbsCertificate (SEQ)
1326 * signatureAlgorithm (AlgorithmIdentifier)
1327 * signatureValue (BIT STRING)
1329 * In turn, tbsCertificate is a sequence of:
1332 * signatureAlgo (AlgorithmIdentifier)
1333 * issuer (Name, has complex structure)
1334 * validity (Validity, SEQ of two Times)
1336 * subjectPublicKeyInfo (SEQ)
1339 * subjectPublicKeyInfo is a sequence of:
1340 * algorithm (AlgorithmIdentifier)
1341 * publicKey (BIT STRING)
1343 * We need Certificate.tbsCertificate.subjectPublicKeyInfo.publicKey
1345 * Example of an ECDSA key:
1346 * SEQ 0x59 bytes (subjectPublicKeyInfo): 3059
1347 * SEQ 0x13 bytes (algorithm): 3013
1348 * OID 7 bytes: 0607 2a8648ce3d0201 (OID_ECDSA_KEY_ALG 42.134.72.206.61.2.1)
1349 * OID 8 bytes: 0608 2a8648ce3d030107 (OID_EC_prime256v1 42.134.72.206.61.3.1.7)
1350 * BITSTRING 0x42 bytes (publicKey): 0342
1351 * 0004 53af f65e 50cc 7959 7e29 0171 c75c
1352 * 7335 e07d f45b 9750 b797 3a38 aebb 2ac6
1353 * 8329 2748 e77e 41cb d482 2ce6 05ec a058
1354 * f3ab d561 2f4c d845 9ad3 7252 e3de bd3b
1357 uint8_t *end = der + len;
1359 /* enter "Certificate" item: [der, end) will be only Cert */
1360 der = enter_der_item(der, &end);
1362 /* enter "tbsCertificate" item: [der, end) will be only tbsCert */
1363 der = enter_der_item(der, &end);
1366 * Skip version field only if it is present. For a v1 certificate, the
1367 * version field won't be present since v1 is the default value for the
1368 * version field and fields with default values should be omitted (see
1369 * RFC 5280 sections 4.1 and 4.1.2.1). If the version field is present
1370 * it will have a tag class of 2 (context-specific), bit 6 as 1
1371 * (constructed), and a tag number of 0 (see ITU-T X.690 sections 8.1.2
1376 /* bits 4-0: 00000 */
1378 der = skip_der_item(der, end); /* version */
1380 /* skip up to subjectPublicKeyInfo */
1381 der = skip_der_item(der, end); /* serialNumber */
1382 der = skip_der_item(der, end); /* signatureAlgo */
1383 der = skip_der_item(der, end); /* issuer */
1384 der = skip_der_item(der, end); /* validity */
1385 der = skip_der_item(der, end); /* subject */
1387 /* enter subjectPublicKeyInfo */
1388 der = enter_der_item(der, &end);
1389 { /* check subjectPublicKeyInfo.algorithm */
1390 static const uint8_t OID_RSA_KEY_ALG[] ALIGN1 = {
1391 0x30,0x0d, // SEQ 13 bytes
1392 0x06,0x09, 0x2a,0x86,0x48,0x86,0xf7,0x0d,0x01,0x01,0x01, //OID_RSA_KEY_ALG 42.134.72.134.247.13.1.1.1
1393 //0x05,0x00, // NULL
1395 static const uint8_t OID_ECDSA_KEY_ALG[] ALIGN1 = {
1396 0x30,0x13, // SEQ 0x13 bytes
1397 0x06,0x07, 0x2a,0x86,0x48,0xce,0x3d,0x02,0x01, //OID_ECDSA_KEY_ALG 42.134.72.206.61.2.1
1398 //allow any curve code for now...
1399 // 0x06,0x08, 0x2a,0x86,0x48,0xce,0x3d,0x03,0x01,0x07, //OID_EC_prime256v1 42.134.72.206.61.3.1.7
1401 //42.134.72.206.61.3 is ellipticCurve
1402 //42.134.72.206.61.3.0 is c-TwoCurve
1403 //42.134.72.206.61.3.1 is primeCurve
1404 //42.134.72.206.61.3.1.7 is curve_secp256r1
1406 if (memcmp(der, OID_RSA_KEY_ALG, sizeof(OID_RSA_KEY_ALG)) == 0) {
1408 tls->flags |= GOT_CERT_RSA_KEY_ALG;
1410 if (memcmp(der, OID_ECDSA_KEY_ALG, sizeof(OID_ECDSA_KEY_ALG)) == 0) {
1412 //UNUSED: tls->flags |= GOT_CERT_ECDSA_KEY_ALG;
1414 bb_simple_error_msg_and_die("not RSA or ECDSA cert");
1417 if (tls->flags & GOT_CERT_RSA_KEY_ALG) {
1418 /* parse RSA key: */
1419 //based on getAsnRsaPubKey(), pkcs1ParsePrivBin() is also of note
1420 /* skip subjectPublicKeyInfo.algorithm */
1421 der = skip_der_item(der, end);
1422 /* enter subjectPublicKeyInfo.publicKey */
1423 //die_if_not_this_der_type(der, end, 0x03); /* must be BITSTRING */
1424 der = enter_der_item(der, &end);
1426 dbg("key bytes:%u, first:0x%02x\n", (int)(end - der), der[0]);
1431 * SEQ 0x018a/394 bytes: 3082018a
1432 * INTEGER 0x0181/385 bytes (modulus): 02820181 XX...XXX
1433 * INTEGER 3 bytes (exponent): 0203 010001
1435 if (*der != 0) /* "ignore bits", should be 0 */
1438 der = enter_der_item(der, &end); /* enter SEQ */
1439 /* memset(tls->hsd->server_rsa_pub_key, 0, sizeof(tls->hsd->server_rsa_pub_key)); - already is */
1440 der_binary_to_pstm(&tls->hsd->server_rsa_pub_key.N, der, end); /* modulus */
1441 der = skip_der_item(der, end);
1442 der_binary_to_pstm(&tls->hsd->server_rsa_pub_key.e, der, end); /* exponent */
1443 tls->hsd->server_rsa_pub_key.size = pstm_unsigned_bin_size(&tls->hsd->server_rsa_pub_key.N);
1444 dbg("server_rsa_pub_key.size:%d\n", tls->hsd->server_rsa_pub_key.size);
1446 /* else: ECDSA key. It is not used for generating encryption keys,
1447 * it is used only to sign the EC public key (which comes in ServerKey message).
1448 * Since we do not verify cert validity, verifying signature on EC public key
1449 * wouldn't add any security. Thus, we do nothing here.
1454 * TLS Handshake routines
1456 static int tls_xread_handshake_block(tls_state_t *tls, int min_len)
1458 struct record_hdr *xhdr;
1459 int len = tls_xread_record(tls, "handshake record");
1461 xhdr = (void*)tls->inbuf;
1463 || xhdr->type != RECORD_TYPE_HANDSHAKE
1465 bad_record_die(tls, "handshake record", len);
1467 dbg("got HANDSHAKE\n");
1471 static ALWAYS_INLINE void fill_handshake_record_hdr(void *buf, unsigned type, unsigned len)
1473 struct handshake_hdr {
1475 uint8_t len24_hi, len24_mid, len24_lo;
1480 h->len24_hi = len >> 16;
1481 h->len24_mid = len >> 8;
1482 h->len24_lo = len & 0xff;
1485 static void send_client_hello_and_alloc_hsd(tls_state_t *tls, const char *sni)
1487 #define NUM_CIPHERS (7 + 6 * ENABLE_FEATURE_TLS_SHA1 + ALLOW_RSA_NULL_SHA256)
1488 static const uint8_t ciphers[] = {
1489 0x00,2 + NUM_CIPHERS*2, //len16_be
1490 0x00,0xFF, //not a cipher - TLS_EMPTY_RENEGOTIATION_INFO_SCSV
1491 /* ^^^^^^ RFC 5746 Renegotiation Indication Extension - some servers will refuse to work with us otherwise */
1492 #if ENABLE_FEATURE_TLS_SHA1
1493 0xC0,0x09, // 1 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA - ok: wget https://is.gd/
1494 0xC0,0x0A, // 2 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA - ok: wget https://is.gd/
1495 0xC0,0x13, // 3 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-SHA
1496 0xC0,0x14, // 4 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA - ok: openssl s_server ... -cipher ECDHE-RSA-AES256-SHA (might fail with older openssl)
1497 // 0xC0,0x18, // TLS_ECDH_anon_WITH_AES_128_CBC_SHA
1498 // 0xC0,0x19, // TLS_ECDH_anon_WITH_AES_256_CBC_SHA
1500 0xC0,0x23, // 5 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 - ok: wget https://is.gd/
1501 // 0xC0,0x24, // TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
1502 0xC0,0x27, // 6 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-SHA256
1503 // 0xC0,0x28, // TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
1504 0xC0,0x2B, // 7 TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 - ok: wget https://is.gd/
1505 // 0xC0,0x2C, // TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 - wget https://is.gd/: "TLS error from peer (alert code 20): bad MAC"
1506 //TODO: GCM_SHA384 ciphers can be supported, only need sha384-based PRF?
1507 0xC0,0x2F, // 8 TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-GCM-SHA256
1508 // 0xC0,0x30, // TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 - openssl s_server ... -cipher ECDHE-RSA-AES256-GCM-SHA384: "decryption failed or bad record mac"
1509 //possibly these too:
1510 #if ENABLE_FEATURE_TLS_SHA1
1511 // 0xC0,0x35, // TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA
1512 // 0xC0,0x36, // TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA
1514 // 0xC0,0x37, // TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256
1515 // 0xC0,0x38, // TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
1516 #if ENABLE_FEATURE_TLS_SHA1
1517 0x00,0x2F, // 9 TLS_RSA_WITH_AES_128_CBC_SHA - ok: openssl s_server ... -cipher AES128-SHA
1518 0x00,0x35, //10 TLS_RSA_WITH_AES_256_CBC_SHA - ok: openssl s_server ... -cipher AES256-SHA
1520 0x00,0x3C, //11 TLS_RSA_WITH_AES_128_CBC_SHA256 - ok: openssl s_server ... -cipher AES128-SHA256
1521 0x00,0x3D, //12 TLS_RSA_WITH_AES_256_CBC_SHA256 - ok: openssl s_server ... -cipher AES256-SHA256
1522 0x00,0x9C, //13 TLS_RSA_WITH_AES_128_GCM_SHA256 - ok: openssl s_server ... -cipher AES128-GCM-SHA256
1523 // 0x00,0x9D, // TLS_RSA_WITH_AES_256_GCM_SHA384 - openssl s_server ... -cipher AES256-GCM-SHA384: "decryption failed or bad record mac"
1524 #if ALLOW_RSA_NULL_SHA256
1525 0x00,0x3B, // TLS_RSA_WITH_NULL_SHA256
1527 0x01,0x00, //not a cipher - comprtypes_len, comprtype
1529 static const uint8_t supported_groups[] = {
1530 0x00,0x0a, //extension_type: "supported_groups"
1531 0x00,0x04, //ext len
1532 0x00,0x02, //list len
1533 0x00,0x1d, //curve_x25519 (RFC 7748)
1534 //0x00,0x1e, //curve_x448 (RFC 7748)
1535 //0x00,0x17, //curve_secp256r1
1536 //0x00,0x18, //curve_secp384r1
1537 //0x00,0x19, //curve_secp521r1
1538 //TODO: implement secp256r1 (at least): dl.fedoraproject.org immediately aborts
1539 //if only x25519/x448 are advertised, seems to support only secpNNNr1 curves:
1540 // openssl s_client -connect dl.fedoraproject.org:443 -debug -tls1_2 -cipher ECDHE-RSA-AES128-GCM-SHA256
1541 //Peer signing digest: SHA512
1542 //Peer signature type: RSA
1543 //Server Temp Key: ECDH, P-256, 256 bits
1544 //TLSv1.2, Cipher is ECDHE-RSA-AES128-GCM-SHA256
1546 //static const uint8_t signature_algorithms[] = {
1550 // 0601 0602 0603 0501 0502 0503 0401 0402 0403 0301 0302 0303 0201 0202 0203
1553 struct client_hello {
1555 uint8_t len24_hi, len24_mid, len24_lo;
1556 uint8_t proto_maj, proto_min;
1558 uint8_t session_id_len;
1559 /* uint8_t session_id[]; */
1560 uint8_t cipherid_len16_hi, cipherid_len16_lo;
1561 uint8_t cipherid[2 + NUM_CIPHERS*2]; /* actually variable */
1562 uint8_t comprtypes_len;
1563 uint8_t comprtypes[1]; /* actually variable */
1564 /* Extensions (SNI shown):
1565 * hi,lo // len of all extensions
1566 * 00,00 // extension_type: "Server Name"
1567 * 00,0e // list len (there can be more than one SNI)
1568 * 00,0c // len of 1st Server Name Indication
1569 * 00 // name type: host_name
1571 * "localhost" // name
1573 // GNU Wget 1.18 to cdn.kernel.org sends these extensions:
1575 // 0005 0005 0100000000 - status_request
1576 // 0000 0013 0011 00 000e 63646e 2e 6b65726e656c 2e 6f7267 - server_name
1577 // ff01 0001 00 - renegotiation_info
1578 // 0023 0000 - session_ticket
1579 // 000a 0008 0006001700180019 - supported_groups
1580 // 000b 0002 0100 - ec_point_formats
1581 // 000d 0016 0014 0401 0403 0501 0503 0601 0603 0301 0303 0201 0203 - signature_algorithms
1582 // wolfssl library sends this option, RFC 7627 (closes a security weakness, some servers may require it. TODO?):
1583 // 0017 0000 - extended master secret
1585 struct client_hello *record;
1589 int sni_len = sni ? strnlen(sni, 127 - 5) : 0;
1592 /* is.gd responds with "handshake failure" to our hello if there's no supported_groups element */
1593 ext_len += sizeof(supported_groups);
1595 ext_len += 9 + sni_len;
1597 /* +2 is for "len of all extensions" 2-byte field */
1598 len = sizeof(*record) + 2 + ext_len;
1599 record = tls_get_zeroed_outbuf(tls, len);
1601 fill_handshake_record_hdr(record, HANDSHAKE_CLIENT_HELLO, len);
1602 record->proto_maj = TLS_MAJ; /* the "requested" version of the protocol, */
1603 record->proto_min = TLS_MIN; /* can be higher than one in record headers */
1604 tls_get_random(record->rand32, sizeof(record->rand32));
1605 if (TLS_DEBUG_FIXED_SECRETS)
1606 memset(record->rand32, 0x11, sizeof(record->rand32));
1607 /* record->session_id_len = 0; - already is */
1609 BUILD_BUG_ON(sizeof(ciphers) != 2 + 2 + NUM_CIPHERS*2 + 2);
1610 memcpy(&record->cipherid_len16_hi, ciphers, sizeof(ciphers));
1612 ptr = (void*)(record + 1);
1613 *ptr++ = ext_len >> 8;
1617 //ptr[1] = 0; //extension_type
1619 ptr[3] = sni_len + 5; //list len
1621 ptr[5] = sni_len + 3; //len of 1st SNI
1622 //ptr[6] = 0; //name type
1624 ptr[8] = sni_len; //name len
1625 ptr = mempcpy(&ptr[9], sni, sni_len);
1627 memcpy(ptr, supported_groups, sizeof(supported_groups));
1629 tls->hsd = xzalloc(sizeof(*tls->hsd));
1630 /* HANDSHAKE HASH: ^^^ + len if need to save saved_client_hello */
1631 memcpy(tls->hsd->client_and_server_rand32, record->rand32, sizeof(record->rand32));
1633 tls->hsd->saved_client_hello_size = len;
1634 memcpy(tls->hsd->saved_client_hello, record, len);
1636 dbg(">> CLIENT_HELLO\n");
1637 /* Can hash immediately only if we know which MAC hash to use.
1638 * So far we do know: it's sha256:
1640 sha256_begin(&tls->hsd->handshake_hash_ctx);
1641 xwrite_and_update_handshake_hash(tls, len);
1642 /* if this would become infeasible: save tls->hsd->saved_client_hello,
1643 * use "xwrite_handshake_record(tls, len)" here,
1644 * and hash saved_client_hello later.
1648 static void get_server_hello(tls_state_t *tls)
1650 struct server_hello {
1651 struct record_hdr xhdr;
1653 uint8_t len24_hi, len24_mid, len24_lo;
1654 uint8_t proto_maj, proto_min;
1655 uint8_t rand32[32]; /* first 4 bytes are unix time in BE format */
1656 uint8_t session_id_len;
1657 uint8_t session_id[32];
1658 uint8_t cipherid_hi, cipherid_lo;
1660 /* extensions may follow, but only those which client offered in its Hello */
1663 struct server_hello *hp;
1668 len = tls_xread_handshake_block(tls, 74 - 32);
1670 hp = (void*)tls->inbuf;
1672 // 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|
1673 //SvHl len=70 maj.min unixtime^^^ 28randbytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^ slen sid32bytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cipSel comprSel
1674 if (hp->type != HANDSHAKE_SERVER_HELLO
1675 || hp->len24_hi != 0
1676 || hp->len24_mid != 0
1677 /* hp->len24_lo checked later */
1678 || hp->proto_maj != TLS_MAJ
1679 || hp->proto_min != TLS_MIN
1681 bad_record_die(tls, "'server hello'", len);
1684 cipherid = &hp->cipherid_hi;
1685 len24 = hp->len24_lo;
1686 if (hp->session_id_len != 32) {
1687 if (hp->session_id_len != 0)
1688 bad_record_die(tls, "'server hello'", len);
1690 // session_id_len == 0: no session id
1692 // may return an empty session_id to indicate that the session will
1693 // not be cached and therefore cannot be resumed."
1695 len24 += 32; /* what len would be if session id would be present */
1699 bad_record_die(tls, "'server hello'", len);
1700 dbg("<< SERVER_HELLO\n");
1702 memcpy(tls->hsd->client_and_server_rand32 + 32, hp->rand32, sizeof(hp->rand32));
1704 /* Set up encryption params based on selected cipher */
1706 #if ENABLE_FEATURE_TLS_SHA1
1707 0xC0,0x09, // 1 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA - ok: wget https://is.gd/
1708 0xC0,0x0A, // 2 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA - ok: wget https://is.gd/
1709 0xC0,0x13, // 3 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-SHA
1710 0xC0,0x14, // 4 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA - ok: openssl s_server ... -cipher ECDHE-RSA-AES256-SHA (might fail with older openssl)
1711 // 0xC0,0x18, // TLS_ECDH_anon_WITH_AES_128_CBC_SHA
1712 // 0xC0,0x19, // TLS_ECDH_anon_WITH_AES_256_CBC_SHA
1714 0xC0,0x23, // 5 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 - ok: wget https://is.gd/
1715 // 0xC0,0x24, // TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
1716 0xC0,0x27, // 6 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-SHA256
1717 // 0xC0,0x28, // TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
1718 0xC0,0x2B, // 7 TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 - ok: wget https://is.gd/
1719 // 0xC0,0x2C, // TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 - wget https://is.gd/: "TLS error from peer (alert code 20): bad MAC"
1720 //TODO: GCM_SHA384 ciphers can be supported, only need sha384-based PRF?
1721 0xC0,0x2F, // 8 TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-GCM-SHA256
1722 // 0xC0,0x30, // TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 - openssl s_server ... -cipher ECDHE-RSA-AES256-GCM-SHA384: "decryption failed or bad record mac"
1723 //possibly these too:
1724 #if ENABLE_FEATURE_TLS_SHA1
1725 // 0xC0,0x35, // TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA
1726 // 0xC0,0x36, // TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA
1728 // 0xC0,0x37, // TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256
1729 // 0xC0,0x38, // TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
1730 #if ENABLE_FEATURE_TLS_SHA1
1731 0x00,0x2F, // 9 TLS_RSA_WITH_AES_128_CBC_SHA - ok: openssl s_server ... -cipher AES128-SHA
1732 0x00,0x35, //10 TLS_RSA_WITH_AES_256_CBC_SHA - ok: openssl s_server ... -cipher AES256-SHA
1734 0x00,0x3C, //11 TLS_RSA_WITH_AES_128_CBC_SHA256 - ok: openssl s_server ... -cipher AES128-SHA256
1735 0x00,0x3D, //12 TLS_RSA_WITH_AES_256_CBC_SHA256 - ok: openssl s_server ... -cipher AES256-SHA256
1736 0x00,0x9C, //13 TLS_RSA_WITH_AES_128_GCM_SHA256 - ok: openssl s_server ... -cipher AES128-GCM-SHA256
1737 // 0x00,0x9D, // TLS_RSA_WITH_AES_256_GCM_SHA384 - openssl s_server ... -cipher AES256-GCM-SHA384: "decryption failed or bad record mac"
1738 #if ALLOW_RSA_NULL_SHA256
1739 0x00,0x3B, // TLS_RSA_WITH_NULL_SHA256
1742 cipherid1 = cipherid[1];
1743 tls->cipher_id = 0x100 * cipherid[0] + cipherid1;
1744 tls->key_size = AES256_KEYSIZE;
1745 tls->MAC_size = SHA256_OUTSIZE;
1746 /*tls->IV_size = 0; - already is */
1747 if (cipherid[0] == 0xC0) {
1748 /* All C0xx are ECDHE */
1749 tls->flags |= NEED_EC_KEY;
1750 if (cipherid1 & 1) {
1751 /* Odd numbered C0xx use AES128 (even ones use AES256) */
1752 tls->key_size = AES128_KEYSIZE;
1754 if (ENABLE_FEATURE_TLS_SHA1 && cipherid1 <= 0x19) {
1755 tls->MAC_size = SHA1_OUTSIZE;
1757 if (cipherid1 >= 0x2B && cipherid1 <= 0x30) {
1758 /* C02B,2C,2F,30 are AES-GCM */
1759 tls->flags |= ENCRYPTION_AESGCM;
1764 /* All 00xx are RSA */
1765 if ((ENABLE_FEATURE_TLS_SHA1 && cipherid1 == 0x2F)
1766 || cipherid1 == 0x3C
1767 || cipherid1 == 0x9C
1769 tls->key_size = AES128_KEYSIZE;
1771 if (ENABLE_FEATURE_TLS_SHA1 && cipherid1 <= 0x35) {
1772 tls->MAC_size = SHA1_OUTSIZE;
1774 if (cipherid1 == 0x9C /*|| cipherid1 == 0x9D*/) {
1775 /* 009C,9D are AES-GCM */
1776 tls->flags |= ENCRYPTION_AESGCM;
1781 dbg("server chose cipher %04x\n", tls->cipher_id);
1782 dbg("key_size:%u MAC_size:%u IV_size:%u\n", tls->key_size, tls->MAC_size, tls->IV_size);
1784 /* Handshake hash eventually destined to FINISHED record
1785 * is sha256 regardless of cipher
1786 * (at least for all ciphers defined by RFC5246).
1787 * It's not sha1 for AES_128_CBC_SHA - only MAC is sha1, not this hash.
1790 sha256_begin(&tls->hsd->handshake_hash_ctx);
1791 hash_handshake(tls, ">> client hello hash:%s",
1792 tls->hsd->saved_client_hello, tls->hsd->saved_client_hello_size
1794 hash_handshake(tls, "<< server hello hash:%s",
1795 tls->inbuf + RECHDR_LEN, len
1800 static void get_server_cert(tls_state_t *tls)
1802 struct record_hdr *xhdr;
1806 len = tls_xread_handshake_block(tls, 10);
1808 xhdr = (void*)tls->inbuf;
1809 certbuf = (void*)(xhdr + 1);
1810 if (certbuf[0] != HANDSHAKE_CERTIFICATE)
1811 bad_record_die(tls, "certificate", len);
1812 dbg("<< CERTIFICATE\n");
1814 // 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...
1815 //Cert len=4388 ChainLen CertLen^ DER encoded X509 starts here. openssl x509 -in FILE -inform DER -noout -text
1816 len1 = get24be(certbuf + 1);
1817 if (len1 > len - 4) tls_error_die(tls);
1819 len1 = get24be(certbuf + 4);
1820 if (len1 > len - 3) tls_error_die(tls);
1822 len1 = get24be(certbuf + 7);
1823 if (len1 > len - 3) tls_error_die(tls);
1827 find_key_in_der_cert(tls, certbuf + 10, len);
1830 /* On input, len is known to be >= 4.
1831 * The record is known to be SERVER_KEY_EXCHANGE.
1833 static void process_server_key(tls_state_t *tls, int len)
1835 struct record_hdr *xhdr;
1840 xhdr = (void*)tls->inbuf;
1841 keybuf = (void*)(xhdr + 1);
1842 //seen from is.gd: it selects curve_x25519:
1843 // 0c 00006e //SERVER_KEY_EXCHANGE, len
1844 // 03 //curve_type: named curve
1845 // 001d //curve_x25519
1846 //server-chosen EC point, and then signed_params
1847 // (RFC 8422: "A hash of the params, with the signature
1848 // appropriate to that hash applied. The private key corresponding
1849 // to the certified public key in the server's Certificate message is
1850 // used for signing.")
1851 //follow. Format unclear/guessed:
1852 // 20 //eccPubKeyLen
1853 // 25511923d73b70dd2f60e66ba2f3fda31a9c25170963c7a3a972e481dbb2835d //eccPubKey (32bytes)
1854 // 0203 //hashSigAlg: 2:SHA1 (4:SHA256 5:SHA384 6:SHA512), 3:ECDSA (1:RSA)
1855 // 0046 //len (16bit)
1857 // 02 20 //INTEGER, len
1858 // 2e18e7c2a9badd0a70cd3059a6ab114539b9f5163568911147386cd77ed7c412 //32bytes
1859 //this item ^^^^^ is sometimes 33 bytes (with all container sizes also +1)
1860 // 02 20 //INTEGER, len
1861 // 64523d6216cb94c43c9b20e377d8c52c55be6703fd6730a155930c705eaf3af6 //32bytes
1862 //same about this item ^^^^^
1864 //seen from ftp.openbsd.org
1865 //(which only accepts ECDHE-RSA-AESnnn-GCM-SHAnnn and ECDHE-RSA-CHACHA20-POLY1305 ciphers):
1866 // 0c 000228 //SERVER_KEY_EXCHANGE, len
1867 // 03 //curve_type: named curve
1868 // 001d //curve_x25519
1869 // 20 //eccPubKeyLen
1870 // eef7a15c43b71a4c7eaa48a39369399cc4332e569ec90a83274cc92596705c1a //eccPubKey
1871 // 0401 //hashSigAlg: 4:SHA256, 1:RSA
1873 // //0x200 bytes follow
1875 /* Get and verify length */
1876 len1 = get24be(keybuf + 1);
1877 if (len1 > len - 4) tls_error_die(tls);
1879 if (len < (1+2+1+32)) tls_error_die(tls);
1882 /* So far we only support curve_x25519 */
1883 move_from_unaligned32(t32, keybuf);
1884 if (t32 != htonl(0x03001d20))
1885 bb_simple_error_msg_and_die("elliptic curve is not x25519");
1887 memcpy(tls->hsd->ecc_pub_key32, keybuf + 4, 32);
1888 tls->flags |= GOT_EC_KEY;
1889 dbg("got eccPubKey\n");
1892 static void send_empty_client_cert(tls_state_t *tls)
1894 struct client_empty_cert {
1896 uint8_t len24_hi, len24_mid, len24_lo;
1897 uint8_t cert_chain_len24_hi, cert_chain_len24_mid, cert_chain_len24_lo;
1899 struct client_empty_cert *record;
1901 record = tls_get_zeroed_outbuf(tls, sizeof(*record));
1902 //fill_handshake_record_hdr(record, HANDSHAKE_CERTIFICATE, sizeof(*record));
1903 //record->cert_chain_len24_hi = 0;
1904 //record->cert_chain_len24_mid = 0;
1905 //record->cert_chain_len24_lo = 0;
1907 record->type = HANDSHAKE_CERTIFICATE;
1908 record->len24_lo = 3;
1910 dbg(">> CERTIFICATE\n");
1911 xwrite_and_update_handshake_hash(tls, sizeof(*record));
1914 static void send_client_key_exchange(tls_state_t *tls)
1916 struct client_key_exchange {
1918 uint8_t len24_hi, len24_mid, len24_lo;
1919 uint8_t key[2 + 4 * 1024]; // size??
1921 //FIXME: better size estimate
1922 struct client_key_exchange *record = tls_get_zeroed_outbuf(tls, sizeof(*record));
1923 uint8_t rsa_premaster[RSA_PREMASTER_SIZE];
1924 uint8_t x25519_premaster[CURVE25519_KEYSIZE];
1929 if (!(tls->flags & NEED_EC_KEY)) {
1931 if (!(tls->flags & GOT_CERT_RSA_KEY_ALG))
1932 bb_simple_error_msg("server cert is not RSA");
1934 tls_get_random(rsa_premaster, sizeof(rsa_premaster));
1935 if (TLS_DEBUG_FIXED_SECRETS)
1936 memset(rsa_premaster, 0x44, sizeof(rsa_premaster));
1938 // "Note: The version number in the PreMasterSecret is the version
1939 // offered by the client in the ClientHello.client_version, not the
1940 // version negotiated for the connection."
1941 rsa_premaster[0] = TLS_MAJ;
1942 rsa_premaster[1] = TLS_MIN;
1943 dump_hex("premaster:%s\n", rsa_premaster, sizeof(rsa_premaster));
1944 len = psRsaEncryptPub(/*pool:*/ NULL,
1945 /* psRsaKey_t* */ &tls->hsd->server_rsa_pub_key,
1946 rsa_premaster, /*inlen:*/ sizeof(rsa_premaster),
1947 record->key + 2, sizeof(record->key) - 2,
1950 /* keylen16 exists for RSA (in TLS, not in SSL), but not for some other key types */
1951 record->key[0] = len >> 8;
1952 record->key[1] = len & 0xff;
1954 premaster = rsa_premaster;
1955 premaster_size = sizeof(rsa_premaster);
1958 static const uint8_t basepoint9[CURVE25519_KEYSIZE] = {9};
1959 uint8_t privkey[CURVE25519_KEYSIZE]; //[32]
1961 if (!(tls->flags & GOT_EC_KEY))
1962 bb_simple_error_msg("server did not provide EC key");
1964 /* Generate random private key, see RFC 7748 */
1965 tls_get_random(privkey, sizeof(privkey));
1967 privkey[CURVE25519_KEYSIZE-1] = ((privkey[CURVE25519_KEYSIZE-1] & 0x7f) | 0x40);
1969 /* Compute public key */
1970 curve25519(record->key + 1, privkey, basepoint9);
1972 /* Compute premaster using peer's public key */
1973 dbg("computing x25519_premaster\n");
1974 curve25519(x25519_premaster, privkey, tls->hsd->ecc_pub_key32);
1976 len = CURVE25519_KEYSIZE;
1977 record->key[0] = len;
1979 premaster = x25519_premaster;
1980 premaster_size = sizeof(x25519_premaster);
1983 record->type = HANDSHAKE_CLIENT_KEY_EXCHANGE;
1984 /* record->len24_hi = 0; - already is */
1985 record->len24_mid = len >> 8;
1986 record->len24_lo = len & 0xff;
1989 dbg(">> CLIENT_KEY_EXCHANGE\n");
1990 xwrite_and_update_handshake_hash(tls, len);
1993 // For all key exchange methods, the same algorithm is used to convert
1994 // the pre_master_secret into the master_secret. The pre_master_secret
1995 // should be deleted from memory once the master_secret has been
1997 // master_secret = PRF(pre_master_secret, "master secret",
1998 // ClientHello.random + ServerHello.random)
2000 // The master secret is always exactly 48 bytes in length. The length
2001 // of the premaster secret will vary depending on key exchange method.
2002 prf_hmac_sha256(/*tls,*/
2003 tls->hsd->master_secret, sizeof(tls->hsd->master_secret),
2004 premaster, premaster_size,
2006 tls->hsd->client_and_server_rand32, sizeof(tls->hsd->client_and_server_rand32)
2008 dump_hex("master secret:%s\n", tls->hsd->master_secret, sizeof(tls->hsd->master_secret));
2011 // 6.3. Key Calculation
2013 // The Record Protocol requires an algorithm to generate keys required
2014 // by the current connection state (see Appendix A.6) from the security
2015 // parameters provided by the handshake protocol.
2017 // The master secret is expanded into a sequence of secure bytes, which
2018 // is then split to a client write MAC key, a server write MAC key, a
2019 // client write encryption key, and a server write encryption key. Each
2020 // of these is generated from the byte sequence in that order. Unused
2021 // values are empty. Some AEAD ciphers may additionally require a
2022 // client write IV and a server write IV (see Section 6.2.3.3).
2024 // When keys and MAC keys are generated, the master secret is used as an
2027 // To generate the key material, compute
2029 // key_block = PRF(SecurityParameters.master_secret,
2031 // SecurityParameters.server_random +
2032 // SecurityParameters.client_random);
2034 // until enough output has been generated. Then, the key_block is
2035 // partitioned as follows:
2037 // client_write_MAC_key[SecurityParameters.mac_key_length]
2038 // server_write_MAC_key[SecurityParameters.mac_key_length]
2039 // client_write_key[SecurityParameters.enc_key_length]
2040 // server_write_key[SecurityParameters.enc_key_length]
2041 // client_write_IV[SecurityParameters.fixed_iv_length]
2042 // server_write_IV[SecurityParameters.fixed_iv_length]
2046 /* make "server_rand32 + client_rand32" */
2047 memcpy(&tmp64[0] , &tls->hsd->client_and_server_rand32[32], 32);
2048 memcpy(&tmp64[32], &tls->hsd->client_and_server_rand32[0] , 32);
2050 prf_hmac_sha256(/*tls,*/
2051 tls->client_write_MAC_key, 2 * (tls->MAC_size + tls->key_size + tls->IV_size),
2053 // server_write_MAC_key[]
2054 // client_write_key[]
2055 // server_write_key[]
2056 // client_write_IV[]
2057 // server_write_IV[]
2058 tls->hsd->master_secret, sizeof(tls->hsd->master_secret),
2062 tls->client_write_key = tls->client_write_MAC_key + (2 * tls->MAC_size);
2063 tls->server_write_key = tls->client_write_key + tls->key_size;
2064 tls->client_write_IV = tls->server_write_key + tls->key_size;
2065 tls->server_write_IV = tls->client_write_IV + tls->IV_size;
2066 dump_hex("client_write_MAC_key:%s\n",
2067 tls->client_write_MAC_key, tls->MAC_size
2069 dump_hex("client_write_key:%s\n",
2070 tls->client_write_key, tls->key_size
2072 dump_hex("client_write_IV:%s\n",
2073 tls->client_write_IV, tls->IV_size
2076 aes_setkey(&tls->aes_decrypt, tls->server_write_key, tls->key_size);
2077 aes_setkey(&tls->aes_encrypt, tls->client_write_key, tls->key_size);
2079 uint8_t iv[AES_BLOCK_SIZE];
2080 memset(iv, 0, AES_BLOCK_SIZE);
2081 aes_encrypt_one_block(&tls->aes_encrypt, iv, tls->H);
2086 static const uint8_t rec_CHANGE_CIPHER_SPEC[] ALIGN1 = {
2087 RECORD_TYPE_CHANGE_CIPHER_SPEC, TLS_MAJ, TLS_MIN, 00, 01,
2091 static void send_change_cipher_spec(tls_state_t *tls)
2093 dbg(">> CHANGE_CIPHER_SPEC\n");
2094 xwrite(tls->ofd, rec_CHANGE_CIPHER_SPEC, sizeof(rec_CHANGE_CIPHER_SPEC));
2098 // A Finished message is always sent immediately after a change
2099 // cipher spec message to verify that the key exchange and
2100 // authentication processes were successful. It is essential that a
2101 // change cipher spec message be received between the other handshake
2102 // messages and the Finished message.
2104 // The Finished message is the first one protected with the just
2105 // negotiated algorithms, keys, and secrets. Recipients of Finished
2106 // messages MUST verify that the contents are correct. Once a side
2107 // has sent its Finished message and received and validated the
2108 // Finished message from its peer, it may begin to send and receive
2109 // application data over the connection.
2112 // opaque verify_data[verify_data_length];
2116 // PRF(master_secret, finished_label, Hash(handshake_messages))
2117 // [0..verify_data_length-1];
2120 // For Finished messages sent by the client, the string
2121 // "client finished". For Finished messages sent by the server,
2122 // the string "server finished".
2124 // Hash denotes a Hash of the handshake messages. For the PRF
2125 // defined in Section 5, the Hash MUST be the Hash used as the basis
2126 // for the PRF. Any cipher suite which defines a different PRF MUST
2127 // also define the Hash to use in the Finished computation.
2129 // In previous versions of TLS, the verify_data was always 12 octets
2130 // long. In the current version of TLS, it depends on the cipher
2131 // suite. Any cipher suite which does not explicitly specify
2132 // verify_data_length has a verify_data_length equal to 12. This
2133 // includes all existing cipher suites.
2134 static void send_client_finished(tls_state_t *tls)
2138 uint8_t len24_hi, len24_mid, len24_lo;
2139 uint8_t prf_result[12];
2141 struct finished *record = tls_get_outbuf(tls, sizeof(*record));
2142 uint8_t handshake_hash[TLS_MAX_MAC_SIZE];
2145 fill_handshake_record_hdr(record, HANDSHAKE_FINISHED, sizeof(*record));
2147 len = sha_end(&tls->hsd->handshake_hash_ctx, handshake_hash);
2149 prf_hmac_sha256(/*tls,*/
2150 record->prf_result, sizeof(record->prf_result),
2151 tls->hsd->master_secret, sizeof(tls->hsd->master_secret),
2155 dump_hex("from secret: %s\n", tls->hsd->master_secret, sizeof(tls->hsd->master_secret));
2156 dump_hex("from labelSeed: %s", "client finished", sizeof("client finished")-1);
2157 dump_hex("%s\n", handshake_hash, sizeof(handshake_hash));
2158 dump_hex("=> digest: %s\n", record->prf_result, sizeof(record->prf_result));
2160 dbg(">> FINISHED\n");
2161 xwrite_encrypted(tls, sizeof(*record), RECORD_TYPE_HANDSHAKE);
2164 void FAST_FUNC tls_handshake(tls_state_t *tls, const char *sni)
2166 // Client RFC 5246 Server
2167 // (*) - optional messages, not always sent
2169 // ClientHello ------->
2172 // ServerKeyExchange*
2173 // CertificateRequest*
2174 // <------- ServerHelloDone
2176 // ClientKeyExchange
2177 // CertificateVerify*
2178 // [ChangeCipherSpec]
2179 // Finished ------->
2180 // [ChangeCipherSpec]
2181 // <------- Finished
2182 // Application Data <------> Application Data
2186 send_client_hello_and_alloc_hsd(tls, sni);
2187 get_server_hello(tls);
2190 // The server MUST send a Certificate message whenever the agreed-
2191 // upon key exchange method uses certificates for authentication
2192 // (this includes all key exchange methods defined in this document
2193 // except DH_anon). This message will always immediately follow the
2194 // ServerHello message.
2196 // IOW: in practice, Certificate *always* follows.
2197 // (for example, kernel.org does not even accept DH_anon cipher id)
2198 get_server_cert(tls);
2200 len = tls_xread_handshake_block(tls, 4);
2201 if (tls->inbuf[RECHDR_LEN] == HANDSHAKE_SERVER_KEY_EXCHANGE) {
2203 // 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...
2205 // with TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA: 461 bytes:
2206 // 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...
2208 // RFC 8422 5.4. Server Key Exchange
2209 // This message is sent when using the ECDHE_ECDSA, ECDHE_RSA, and
2210 // ECDH_anon key exchange algorithms.
2211 // This message is used to convey the server's ephemeral ECDH public key
2212 // (and the corresponding elliptic curve domain parameters) to the
2214 dbg("<< SERVER_KEY_EXCHANGE len:%u\n", len);
2215 dump_raw_in("<< %s\n", tls->inbuf, RECHDR_LEN + len);
2216 if (tls->flags & NEED_EC_KEY)
2217 process_server_key(tls, len);
2219 // read next handshake block
2220 len = tls_xread_handshake_block(tls, 4);
2223 got_cert_req = (tls->inbuf[RECHDR_LEN] == HANDSHAKE_CERTIFICATE_REQUEST);
2225 dbg("<< CERTIFICATE_REQUEST\n");
2226 // RFC 5246: "If no suitable certificate is available,
2227 // the client MUST send a certificate message containing no
2228 // certificates. That is, the certificate_list structure has a
2229 // length of zero. ...
2230 // Client certificates are sent using the Certificate structure
2231 // defined in Section 7.4.2."
2232 // (i.e. the same format as server certs)
2234 /*send_empty_client_cert(tls); - WRONG (breaks handshake hash calc) */
2235 /* need to hash _all_ server replies first, up to ServerHelloDone */
2236 len = tls_xread_handshake_block(tls, 4);
2239 if (tls->inbuf[RECHDR_LEN] != HANDSHAKE_SERVER_HELLO_DONE) {
2240 bad_record_die(tls, "'server hello done'", len);
2242 // 0e 000000 (len:0)
2243 dbg("<< SERVER_HELLO_DONE\n");
2246 send_empty_client_cert(tls);
2248 send_client_key_exchange(tls);
2250 send_change_cipher_spec(tls);
2251 /* from now on we should send encrypted */
2252 /* tls->write_seq64_be = 0; - already is */
2253 tls->flags |= ENCRYPT_ON_WRITE;
2255 send_client_finished(tls);
2257 /* Get CHANGE_CIPHER_SPEC */
2258 len = tls_xread_record(tls, "switch to encrypted traffic");
2259 if (len != 1 || memcmp(tls->inbuf, rec_CHANGE_CIPHER_SPEC, 6) != 0)
2260 bad_record_die(tls, "switch to encrypted traffic", len);
2261 dbg("<< CHANGE_CIPHER_SPEC\n");
2263 if (ALLOW_RSA_NULL_SHA256
2264 && tls->cipher_id == TLS_RSA_WITH_NULL_SHA256
2266 tls->min_encrypted_len_on_read = tls->MAC_size;
2268 if (!(tls->flags & ENCRYPTION_AESGCM)) {
2269 unsigned mac_blocks = (unsigned)(TLS_MAC_SIZE(tls) + AES_BLOCK_SIZE-1) / AES_BLOCK_SIZE;
2270 /* all incoming packets now should be encrypted and have
2271 * at least IV + (MAC padded to blocksize):
2273 tls->min_encrypted_len_on_read = AES_BLOCK_SIZE + (mac_blocks * AES_BLOCK_SIZE);
2275 tls->min_encrypted_len_on_read = 8 + AES_BLOCK_SIZE;
2277 dbg("min_encrypted_len_on_read: %u\n", tls->min_encrypted_len_on_read);
2279 /* Get (encrypted) FINISHED from the server */
2280 len = tls_xread_record(tls, "'server finished'");
2281 if (len < 4 || tls->inbuf[RECHDR_LEN] != HANDSHAKE_FINISHED)
2282 bad_record_die(tls, "'server finished'", len);
2283 dbg("<< FINISHED\n");
2284 /* application data can be sent/received */
2286 /* free handshake data */
2287 psRsaKey_clear(&tls->hsd->server_rsa_pub_key);
2289 // memset(tls->hsd, 0, tls->hsd->hsd_size);
2294 static void tls_xwrite(tls_state_t *tls, int len)
2297 xwrite_encrypted(tls, len, RECORD_TYPE_APPLICATION_DATA);
2300 // To run a test server using openssl:
2301 // openssl req -x509 -newkey rsa:$((4096/4*3)) -keyout key.pem -out server.pem -nodes -days 99999 -subj '/CN=localhost'
2302 // openssl s_server -key key.pem -cert server.pem -debug -tls1_2
2304 // Unencryped SHA256 example:
2305 // openssl req -x509 -newkey rsa:$((4096/4*3)) -keyout key.pem -out server.pem -nodes -days 99999 -subj '/CN=localhost'
2306 // openssl s_server -key key.pem -cert server.pem -debug -tls1_2 -cipher NULL
2307 // openssl s_client -connect 127.0.0.1:4433 -debug -tls1_2 -cipher NULL-SHA256
2309 void FAST_FUNC tls_run_copy_loop(tls_state_t *tls, unsigned flags)
2312 const int INBUF_STEP = 4 * 1024;
2313 struct pollfd pfds[2];
2315 pfds[0].fd = STDIN_FILENO;
2316 pfds[0].events = POLLIN;
2317 pfds[1].fd = tls->ifd;
2318 pfds[1].events = POLLIN;
2320 inbuf_size = INBUF_STEP;
2324 if (safe_poll(pfds, 2, -1) < 0)
2325 bb_simple_perror_msg_and_die("poll");
2327 if (pfds[0].revents) {
2330 dbg("STDIN HAS DATA\n");
2331 buf = tls_get_outbuf(tls, inbuf_size);
2332 nread = safe_read(STDIN_FILENO, buf, inbuf_size);
2334 /* We'd want to do this: */
2335 /* Close outgoing half-connection so they get EOF,
2336 * but leave incoming alone so we can see response
2338 //shutdown(tls->ofd, SHUT_WR);
2339 /* But TLS has no way to encode this,
2340 * doubt it's ok to do it "raw"
2343 tls_free_outbuf(tls); /* mem usage optimization */
2344 if (flags & TLSLOOP_EXIT_ON_LOCAL_EOF)
2347 if (nread == inbuf_size) {
2348 /* TLS has per record overhead, if input comes fast,
2349 * read, encrypt and send bigger chunks
2351 inbuf_size += INBUF_STEP;
2352 if (inbuf_size > TLS_MAX_OUTBUF)
2353 inbuf_size = TLS_MAX_OUTBUF;
2355 tls_xwrite(tls, nread);
2358 if (pfds[1].revents) {
2359 dbg("NETWORK HAS DATA\n");
2361 nread = tls_xread_record(tls, "encrypted data");
2363 /* TLS protocol has no real concept of one-sided shutdowns:
2364 * if we get "TLS EOF" from the peer, writes will fail too
2367 //close(STDOUT_FILENO);
2368 //tls_free_inbuf(tls); /* mem usage optimization */
2372 if (tls->inbuf[0] != RECORD_TYPE_APPLICATION_DATA)
2373 bad_record_die(tls, "encrypted data", nread);
2374 xwrite(STDOUT_FILENO, tls->inbuf + RECHDR_LEN, nread);
2375 /* We may already have a complete next record buffered,
2376 * can process it without network reads (and possible blocking)
2378 if (tls_has_buffered_record(tls))