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_aes.o
16 //kbuild:lib-$(CONFIG_TLS) += tls_aesgcm.o
17 //kbuild:lib-$(CONFIG_TLS) += tls_rsa.o
18 //kbuild:lib-$(CONFIG_TLS) += tls_fe.o
22 // works against "openssl s_server -cipher NULL"
23 // and against wolfssl-3.9.10-stable/examples/server/server.c:
24 #define ALLOW_RSA_NULL_SHA256 0 // for testing (does everything except encrypting)
26 //Tested against kernel.org:
27 //#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA // ok, recvs SERVER_KEY_EXCHANGE *** matrixssl uses this on my box
28 //#define CIPHER_ID TLS_RSA_WITH_AES_256_CBC_SHA256 // ok, no SERVER_KEY_EXCHANGE
29 //#define CIPHER_ID TLS_DH_anon_WITH_AES_256_CBC_SHA // SSL_ALERT_HANDSHAKE_FAILURE
30 //^^^^^^^^^^^^^^^^^^^^^^^ (tested b/c this one doesn't req server certs... no luck, server refuses it)
31 //#define CIPHER_ID TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 // SSL_ALERT_HANDSHAKE_FAILURE
32 //#define CIPHER_ID TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
33 //#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 // ok, recvs SERVER_KEY_EXCHANGE
34 //#define CIPHER_ID TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
35 //#define CIPHER_ID TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384
36 //#define CIPHER_ID TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
37 //#define CIPHER_ID TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384
38 //#define CIPHER_ID TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 // SSL_ALERT_HANDSHAKE_FAILURE
39 //#define CIPHER_ID TLS_RSA_WITH_AES_256_GCM_SHA384 // ok, no SERVER_KEY_EXCHANGE
40 //#define CIPHER_ID TLS_RSA_WITH_AES_128_GCM_SHA256 // ok, no SERVER_KEY_EXCHANGE
42 // works against wolfssl-3.9.10-stable/examples/server/server.c
43 // works for kernel.org
44 // does not work for cdn.kernel.org (e.g. downloading an actual tarball, not a web page)
45 // getting alert 40 "handshake failure" at once
46 // with GNU Wget 1.18, they agree on TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (0xC02F) cipher
47 // fail: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -cipher AES256-SHA256
48 // fail: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -cipher AES256-GCM-SHA384
49 // fail: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -cipher AES128-SHA256
50 // ok: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -cipher AES128-GCM-SHA256
51 // ok: openssl s_client -connect cdn.kernel.org:443 -debug -tls1_2 -cipher AES128-SHA
52 // (TLS_RSA_WITH_AES_128_CBC_SHA - in TLS 1.2 it's mandated to be always supported)
53 //#define CIPHER_ID1 TLS_RSA_WITH_AES_256_CBC_SHA256 //0x003D
54 // Works with "wget https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.9.5.tar.xz"
55 //#define CIPHER_ID2 TLS_RSA_WITH_AES_128_CBC_SHA //0x002F
58 // ftp.openbsd.org only supports ECDHE-RSA-AESnnn-GCM-SHAnnn or ECDHE-RSA-CHACHA20-POLY1305
59 //#define CIPHER_ID3 TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 //0xC02F
60 // host is.gd accepts only ECDHE-ECDSA-foo (the simplest which works: ECDHE-ECDSA-AES128-SHA 0xC009)
61 //#define CIPHER_ID4 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA //0xC009
65 #define TLS_DEBUG_HASH 0
66 #define TLS_DEBUG_DER 0
67 #define TLS_DEBUG_FIXED_SECRETS 0
69 # define dump_raw_out(...) dump_hex(__VA_ARGS__)
71 # define dump_raw_out(...) ((void)0)
74 # define dump_raw_in(...) dump_hex(__VA_ARGS__)
76 # define dump_raw_in(...) ((void)0)
80 # define dbg(...) fprintf(stderr, __VA_ARGS__)
82 # define dbg(...) ((void)0)
86 # define dbg_der(...) fprintf(stderr, __VA_ARGS__)
88 # define dbg_der(...) ((void)0)
96 #define RECORD_TYPE_CHANGE_CIPHER_SPEC 20 /* 0x14 */
97 #define RECORD_TYPE_ALERT 21 /* 0x15 */
98 #define RECORD_TYPE_HANDSHAKE 22 /* 0x16 */
99 #define RECORD_TYPE_APPLICATION_DATA 23 /* 0x17 */
101 #define HANDSHAKE_HELLO_REQUEST 0 /* 0x00 */
102 #define HANDSHAKE_CLIENT_HELLO 1 /* 0x01 */
103 #define HANDSHAKE_SERVER_HELLO 2 /* 0x02 */
104 #define HANDSHAKE_HELLO_VERIFY_REQUEST 3 /* 0x03 */
105 #define HANDSHAKE_NEW_SESSION_TICKET 4 /* 0x04 */
106 #define HANDSHAKE_CERTIFICATE 11 /* 0x0b */
107 #define HANDSHAKE_SERVER_KEY_EXCHANGE 12 /* 0x0c */
108 #define HANDSHAKE_CERTIFICATE_REQUEST 13 /* 0x0d */
109 #define HANDSHAKE_SERVER_HELLO_DONE 14 /* 0x0e */
110 #define HANDSHAKE_CERTIFICATE_VERIFY 15 /* 0x0f */
111 #define HANDSHAKE_CLIENT_KEY_EXCHANGE 16 /* 0x10 */
112 #define HANDSHAKE_FINISHED 20 /* 0x14 */
114 #define TLS_EMPTY_RENEGOTIATION_INFO_SCSV 0x00FF /* not a real cipher id... */
116 #define SSL_NULL_WITH_NULL_NULL 0x0000
117 #define SSL_RSA_WITH_NULL_MD5 0x0001
118 #define SSL_RSA_WITH_NULL_SHA 0x0002
119 #define SSL_RSA_WITH_RC4_128_MD5 0x0004
120 #define SSL_RSA_WITH_RC4_128_SHA 0x0005
121 #define TLS_RSA_WITH_IDEA_CBC_SHA 0x0007 /* 7 */
122 #define SSL_RSA_WITH_3DES_EDE_CBC_SHA 0x000A /* 10 */
124 #define SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA 0x0016 /* 22 */
125 #define SSL_DH_anon_WITH_RC4_128_MD5 0x0018 /* 24 */
126 #define SSL_DH_anon_WITH_3DES_EDE_CBC_SHA 0x001B /* 27 */
127 #define TLS_RSA_WITH_AES_128_CBC_SHA 0x002F /*SSLv3 Kx=RSA Au=RSA Enc=AES(128) Mac=SHA1 */
128 #define TLS_DHE_RSA_WITH_AES_128_CBC_SHA 0x0033 /* 51 */
129 #define TLS_DH_anon_WITH_AES_128_CBC_SHA 0x0034 /* 52 */
130 #define TLS_RSA_WITH_AES_256_CBC_SHA 0x0035 /* 53 */
131 #define TLS_DHE_RSA_WITH_AES_256_CBC_SHA 0x0039 /* 57 */
132 #define TLS_DH_anon_WITH_AES_256_CBC_SHA 0x003A /* 58 */
133 #define TLS_RSA_WITH_NULL_SHA256 0x003B /* 59 */
134 #define TLS_RSA_WITH_AES_128_CBC_SHA256 0x003C /* 60 */
135 #define TLS_RSA_WITH_AES_256_CBC_SHA256 0x003D /* 61 */
136 #define TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 0x0067 /* 103 */
137 #define TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 0x006B /* 107 */
138 #define TLS_PSK_WITH_AES_128_CBC_SHA 0x008C /* 140 */
139 #define TLS_PSK_WITH_AES_256_CBC_SHA 0x008D /* 141 */
140 #define TLS_DHE_PSK_WITH_AES_128_CBC_SHA 0x0090 /* 144 */
141 #define TLS_DHE_PSK_WITH_AES_256_CBC_SHA 0x0091 /* 145 */
142 #define TLS_RSA_WITH_SEED_CBC_SHA 0x0096 /* 150 */
143 #define TLS_RSA_WITH_AES_128_GCM_SHA256 0x009C /*TLSv1.2 Kx=RSA Au=RSA Enc=AESGCM(128) Mac=AEAD */
144 #define TLS_RSA_WITH_AES_256_GCM_SHA384 0x009D /*TLSv1.2 Kx=RSA Au=RSA Enc=AESGCM(256) Mac=AEAD */
145 #define TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 0x009E /*TLSv1.2 Kx=DH Au=RSA Enc=AESGCM(128) Mac=AEAD */
146 #define TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 0x009F /*TLSv1.2 Kx=DH Au=RSA Enc=AESGCM(256) Mac=AEAD */
147 #define TLS_DH_anon_WITH_AES_128_GCM_SHA256 0x00A6 /* RFC 5288 */
148 #define TLS_DH_anon_WITH_AES_256_GCM_SHA384 0x00A7 /* RFC 5288 */
149 #define TLS_PSK_WITH_AES_128_CBC_SHA256 0x00AE /* 174 */
150 #define TLS_PSK_WITH_AES_256_CBC_SHA384 0x00AF /* 175 */
151 #define TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA 0xC004 /* 49156 */
152 #define TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA 0xC005 /* 49157 */
153 #define TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA 0xC009 /*TLSv1 Kx=ECDH Au=ECDSA Enc=AES(128) Mac=SHA1 */
154 #define TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA 0xC00A /*TLSv1 Kx=ECDH Au=ECDSA Enc=AES(256) Mac=SHA1 */
155 #define TLS_ECDH_RSA_WITH_AES_128_CBC_SHA 0xC00E /* 49166 */
156 #define TLS_ECDH_RSA_WITH_AES_256_CBC_SHA 0xC00F /* 49167 */
157 #define TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA 0xC012 /* 49170 */
158 #define TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA 0xC013 /*TLSv1 Kx=ECDH Au=RSA Enc=AES(128) Mac=SHA1 */
159 #define TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA 0xC014 /*TLSv1 Kx=ECDH Au=RSA Enc=AES(256) Mac=SHA1 */
160 #define TLS_ECDH_anon_WITH_AES_128_CBC_SHA 0xC018 /* RFC 4492 */
161 #define TLS_ECDH_anon_WITH_AES_256_CBC_SHA 0xC019 /* RFC 4492 */
162 #define TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 0xC023 /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AES(128) Mac=SHA256 */
163 #define TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 0xC024 /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AES(256) Mac=SHA384 */
164 #define TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 0xC025 /* 49189 */
165 #define TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 0xC026 /* 49190 */
166 #define TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 0xC027 /*TLSv1.2 Kx=ECDH Au=RSA Enc=AES(128) Mac=SHA256 */
167 #define TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 0xC028 /*TLSv1.2 Kx=ECDH Au=RSA Enc=AES(256) Mac=SHA384 */
168 #define TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 0xC029 /* 49193 */
169 #define TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 0xC02A /* 49194 */
170 /* RFC 5288 "AES Galois Counter Mode (GCM) Cipher Suites for TLS" */
171 #define TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 0xC02B /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESGCM(128) Mac=AEAD */
172 #define TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 0xC02C /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESGCM(256) Mac=AEAD */
173 #define TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 0xC02D /* 49197 */
174 #define TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 0xC02E /* 49198 */
175 #define TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 0xC02F /*TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(128) Mac=AEAD */
176 #define TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 0xC030 /*TLSv1.2 Kx=ECDH Au=RSA Enc=AESGCM(256) Mac=AEAD */
177 #define TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 0xC031 /* 49201 */
178 #define TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 0xC032 /* 49202 */
179 #define TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA 0xC035
180 #define TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA 0xC036
181 #define TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256 0xC037
182 #define TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384 0xC038
184 /* From http://wiki.mozilla.org/Security/Server_Side_TLS */
185 /* and 'openssl ciphers -V -stdname' */
186 #define TLS_RSA_WITH_AES_128_CCM 0xC09C /*TLSv1.2 Kx=RSA Au=RSA Enc=AESCCM(128) Mac=AEAD */
187 #define TLS_RSA_WITH_AES_256_CCM 0xC09D /*TLSv1.2 Kx=RSA Au=RSA Enc=AESCCM(256) Mac=AEAD */
188 #define TLS_DHE_RSA_WITH_AES_128_CCM 0xC09E /*TLSv1.2 Kx=DH Au=RSA Enc=AESCCM(128) Mac=AEAD */
189 #define TLS_DHE_RSA_WITH_AES_256_CCM 0xC09F /*TLSv1.2 Kx=DH Au=RSA Enc=AESCCM(256) Mac=AEAD */
190 #define TLS_RSA_WITH_AES_128_CCM_8 0xC0A0 /*TLSv1.2 Kx=RSA Au=RSA Enc=AESCCM8(128) Mac=AEAD */
191 #define TLS_RSA_WITH_AES_256_CCM_8 0xC0A1 /*TLSv1.2 Kx=RSA Au=RSA Enc=AESCCM8(256) Mac=AEAD */
192 #define TLS_DHE_RSA_WITH_AES_128_CCM_8 0xC0A2 /*TLSv1.2 Kx=DH Au=RSA Enc=AESCCM8(128) Mac=AEAD */
193 #define TLS_DHE_RSA_WITH_AES_256_CCM_8 0xC0A3 /*TLSv1.2 Kx=DH Au=RSA Enc=AESCCM8(256) Mac=AEAD */
194 #define TLS_ECDHE_ECDSA_WITH_AES_128_CCM 0xC0AC /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESCCM(128) Mac=AEAD */
195 #define TLS_ECDHE_ECDSA_WITH_AES_256_CCM 0xC0AD /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESCCM(256) Mac=AEAD */
196 #define TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8 0xC0AE /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESCCM8(128) Mac=AEAD */
197 #define TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8 0xC0AF /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=AESCCM8(256) Mac=AEAD */
198 #define TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 0xCCA8 /*TLSv1.2 Kx=ECDH Au=RSA Enc=CHACHA20/POLY1305(256) Mac=AEAD */
199 #define TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 0xCCA9 /*TLSv1.2 Kx=ECDH Au=ECDSA Enc=CHACHA20/POLY1305(256) Mac=AEAD */
200 #define TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 0xCCAA /*TLSv1.2 Kx=DH Au=RSA Enc=CHACHA20/POLY1305(256) Mac=AEAD */
202 #define TLS_AES_128_GCM_SHA256 0x1301 /*TLSv1.3 Kx=any Au=any Enc=AESGCM(128) Mac=AEAD */
203 #define TLS_AES_256_GCM_SHA384 0x1302 /*TLSv1.3 Kx=any Au=any Enc=AESGCM(256) Mac=AEAD */
204 #define TLS_CHACHA20_POLY1305_SHA256 0x1303 /*TLSv1.3 Kx=any Au=any Enc=CHACHA20/POLY1305(256) Mac=AEAD */
205 #define TLS_AES_128_CCM_SHA256 0x1304 /*TLSv1.3 Kx=any Au=any Enc=AESCCM(128) Mac=AEAD */
207 /* Might go to libbb.h */
208 #define TLS_MAX_CRYPTBLOCK_SIZE 16
209 #define TLS_MAX_OUTBUF (1 << 14)
219 RSA_PREMASTER_SIZE = 48,
223 /* 8 = 3+5. 3 extra bytes result in record data being 32-bit aligned */
224 OUTBUF_PFX = 8 + AES_BLOCK_SIZE, /* header + IV */
225 OUTBUF_SFX = TLS_MAX_MAC_SIZE + TLS_MAX_CRYPTBLOCK_SIZE, /* MAC + padding */
228 // | 6.2.1. Fragmentation
229 // | The record layer fragments information blocks into TLSPlaintext
230 // | records carrying data in chunks of 2^14 bytes or less. Client
231 // | message boundaries are not preserved in the record layer (i.e.,
232 // | multiple client messages of the same ContentType MAY be coalesced
233 // | into a single TLSPlaintext record, or a single message MAY be
234 // | fragmented across several records)
237 // | The length (in bytes) of the following TLSPlaintext.fragment.
238 // | The length MUST NOT exceed 2^14.
240 // | 6.2.2. Record Compression and Decompression
242 // | Compression must be lossless and may not increase the content length
243 // | by more than 1024 bytes. If the decompression function encounters a
244 // | TLSCompressed.fragment that would decompress to a length in excess of
245 // | 2^14 bytes, it MUST report a fatal decompression failure error.
248 // | The length (in bytes) of the following TLSCompressed.fragment.
249 // | The length MUST NOT exceed 2^14 + 1024.
251 // | 6.2.3. Record Payload Protection
252 // | The encryption and MAC functions translate a TLSCompressed
253 // | structure into a TLSCiphertext. The decryption functions reverse
254 // | the process. The MAC of the record also includes a sequence
255 // | number so that missing, extra, or repeated messages are
259 // | The length (in bytes) of the following TLSCiphertext.fragment.
260 // | The length MUST NOT exceed 2^14 + 2048.
261 MAX_INBUF = RECHDR_LEN + (1 << 14) + 2048,
263 /* Bits for tls->flags */
264 NEED_EC_KEY = 1 << 0,
265 GOT_CERT_RSA_KEY_ALG = 1 << 1,
266 GOT_CERT_ECDSA_KEY_ALG = 1 << 2, // so far unused
268 ENCRYPTION_AESGCM = 1 << 4, // else AES-SHA (or NULL-SHA if ALLOW_RSA_NULL_SHA256=1)
269 ENCRYPT_ON_WRITE = 1 << 5,
274 uint8_t proto_maj, proto_min;
275 uint8_t len16_hi, len16_lo;
278 struct tls_handshake_data {
279 /* In bbox, md5/sha1/sha256 ctx's are the same structure */
280 md5sha_ctx_t handshake_hash_ctx;
282 uint8_t client_and_server_rand32[2 * 32];
283 uint8_t master_secret[48];
285 //TODO: store just the DER key here, parse/use/delete it when sending client key
286 //this way it will stay key type agnostic here.
287 psRsaKey_t server_rsa_pub_key;
288 uint8_t ecc_pub_key32[32];
290 /* HANDSHAKE HASH: */
291 //unsigned saved_client_hello_size;
292 //uint8_t saved_client_hello[1];
296 static unsigned get24be(const uint8_t *p)
298 return 0x100*(0x100*p[0] + p[1]) + p[2];
302 /* Nondestructively see the current hash value */
304 static unsigned sha_peek(md5sha_ctx_t *ctx, void *buffer)
306 md5sha_ctx_t ctx_copy = *ctx; /* struct copy */
307 return sha_end(&ctx_copy, buffer);
311 static void dump_hex(const char *fmt, const void *vp, int len)
313 char hexbuf[32 * 1024 + 4];
314 const uint8_t *p = vp;
316 bin2hex(hexbuf, (void*)p, len)[0] = '\0';
320 static void dump_tls_record(const void *vp, int len)
322 const uint8_t *p = vp;
326 if (len < RECHDR_LEN) {
327 dump_hex("< |%s|\n", p, len);
330 xhdr_len = 0x100*p[3] + p[4];
331 dbg("< hdr_type:%u ver:%u.%u len:%u", p[0], p[1], p[2], xhdr_len);
334 if (len >= 4 && p[-RECHDR_LEN] == RECORD_TYPE_HANDSHAKE) {
335 unsigned len24 = get24be(p + 1);
336 dbg(" type:%u len24:%u", p[0], len24);
340 dump_hex(" |%s|\n", p, xhdr_len);
346 # define dump_hex(...) ((void)0)
347 # define dump_tls_record(...) ((void)0)
350 void FAST_FUNC tls_get_random(void *buf, unsigned len)
352 if (len != open_read_close("/dev/urandom", buf, len))
356 static void xorbuf3(void *dst, const void *src1, const void *src2, unsigned count)
359 const uint8_t *s1 = src1;
360 const uint8_t* s2 = src2;
362 *d++ = *s1++ ^ *s2++;
365 void FAST_FUNC xorbuf(void *dst, const void *src, unsigned count)
367 xorbuf3(dst, dst, src, count);
370 void FAST_FUNC xorbuf_aligned_AES_BLOCK_SIZE(void *dst, const void *src)
372 unsigned long *d = dst;
373 const unsigned long *s = src;
375 #if ULONG_MAX <= 0xffffffffffffffff
377 #if ULONG_MAX == 0xffffffff
385 # define hash_handshake(tls, fmt, buffer, len) \
386 hash_handshake(tls, buffer, len)
388 static void hash_handshake(tls_state_t *tls, const char *fmt, const void *buffer, unsigned len)
390 md5sha_hash(&tls->hsd->handshake_hash_ctx, buffer, len);
393 uint8_t h[TLS_MAX_MAC_SIZE];
394 dump_hex(fmt, buffer, len);
395 dbg(" (%u bytes) ", (int)len);
396 len = sha_peek(&tls->hsd->handshake_hash_ctx, h);
397 if (len == SHA1_OUTSIZE)
398 dump_hex("sha1:%s\n", h, len);
400 if (len == SHA256_OUTSIZE)
401 dump_hex("sha256:%s\n", h, len);
403 dump_hex("sha???:%s\n", h, len);
409 // HMAC(key, text) based on a hash H (say, sha256) is:
410 // ipad = [0x36 x INSIZE]
411 // opad = [0x5c x INSIZE]
412 // HMAC(key, text) = H((key XOR opad) + H((key XOR ipad) + text))
414 // H(key XOR opad) and H(key XOR ipad) can be precomputed
415 // if we often need HMAC hmac with the same key.
417 // text is often given in disjoint pieces.
418 typedef struct hmac_precomputed {
419 md5sha_ctx_t hashed_key_xor_ipad;
420 md5sha_ctx_t hashed_key_xor_opad;
421 } hmac_precomputed_t;
423 typedef void md5sha_begin_func(md5sha_ctx_t *ctx) FAST_FUNC;
424 static void hmac_begin(hmac_precomputed_t *pre, uint8_t *key, unsigned key_size, md5sha_begin_func *begin)
426 uint8_t key_xor_ipad[SHA_INSIZE];
427 uint8_t key_xor_opad[SHA_INSIZE];
428 // uint8_t tempkey[SHA1_OUTSIZE < SHA256_OUTSIZE ? SHA256_OUTSIZE : SHA1_OUTSIZE];
431 // "The authentication key can be of any length up to INSIZE, the
432 // block length of the hash function. Applications that use keys longer
433 // than INSIZE bytes will first hash the key using H and then use the
434 // resultant OUTSIZE byte string as the actual key to HMAC."
435 if (key_size > SHA_INSIZE) {
436 bb_error_msg_and_die("HMAC key>64"); //does not happen (yet?)
439 // md5sha_hash(&ctx, key, key_size);
440 // key_size = sha_end(&ctx, tempkey);
441 // //key = tempkey; - right? RIGHT? why does it work without this?
442 // // because SHA_INSIZE is 64, but hmac() is always called with
443 // // key_size = tls->MAC_size = SHA1/256_OUTSIZE (20 or 32),
444 // // and prf_hmac_sha256() -> hmac_sha256() key sizes are:
445 // // - RSA_PREMASTER_SIZE is 48
446 // // - CURVE25519_KEYSIZE is 32
447 // // - master_secret[] is 48
450 for (i = 0; i < key_size; i++) {
451 key_xor_ipad[i] = key[i] ^ 0x36;
452 key_xor_opad[i] = key[i] ^ 0x5c;
454 for (; i < SHA_INSIZE; i++) {
455 key_xor_ipad[i] = 0x36;
456 key_xor_opad[i] = 0x5c;
459 begin(&pre->hashed_key_xor_ipad);
460 begin(&pre->hashed_key_xor_opad);
461 md5sha_hash(&pre->hashed_key_xor_ipad, key_xor_ipad, SHA_INSIZE);
462 md5sha_hash(&pre->hashed_key_xor_opad, key_xor_opad, SHA_INSIZE);
465 static unsigned hmac_sha_precomputed_v(
466 hmac_precomputed_t *pre,
473 /* pre->hashed_key_xor_ipad contains unclosed "H((key XOR ipad) +" state */
474 /* pre->hashed_key_xor_opad contains unclosed "H((key XOR opad) +" state */
476 /* calculate out = H((key XOR ipad) + text) */
477 while ((text = va_arg(va, uint8_t*)) != NULL) {
478 unsigned text_size = va_arg(va, unsigned);
479 md5sha_hash(&pre->hashed_key_xor_ipad, text, text_size);
481 len = sha_end(&pre->hashed_key_xor_ipad, out);
483 /* out = H((key XOR opad) + out) */
484 md5sha_hash(&pre->hashed_key_xor_opad, out, len);
485 return sha_end(&pre->hashed_key_xor_opad, out);
488 static unsigned hmac_sha_precomputed(hmac_precomputed_t *pre_init, uint8_t *out, ...)
490 hmac_precomputed_t pre;
495 pre = *pre_init; /* struct copy */
496 len = hmac_sha_precomputed_v(&pre, out, va);
501 static unsigned hmac(tls_state_t *tls, uint8_t *out, uint8_t *key, unsigned key_size, ...)
503 hmac_precomputed_t pre;
507 va_start(va, key_size);
509 hmac_begin(&pre, key, key_size,
510 (tls->MAC_size == SHA256_OUTSIZE)
514 len = hmac_sha_precomputed_v(&pre, out, va);
521 // 5. HMAC and the Pseudorandom Function
523 // In this section, we define one PRF, based on HMAC. This PRF with the
524 // SHA-256 hash function is used for all cipher suites defined in this
525 // document and in TLS documents published prior to this document when
526 // TLS 1.2 is negotiated.
527 // ^^^^^^^^^^^^^ IMPORTANT!
528 // PRF uses sha256 regardless of cipher for all ciphers
529 // defined by RFC 5246. It's not sha1 for AES_128_CBC_SHA!
530 // However, for _SHA384 ciphers, it's sha384. See RFC 5288,5289.
532 // P_hash(secret, seed) = HMAC_hash(secret, A(1) + seed) +
533 // HMAC_hash(secret, A(2) + seed) +
534 // HMAC_hash(secret, A(3) + seed) + ...
535 // where + indicates concatenation.
536 // A() is defined as:
538 // A(1) = HMAC_hash(secret, A(0)) = HMAC_hash(secret, seed)
539 // A(i) = HMAC_hash(secret, A(i-1))
540 // P_hash can be iterated as many times as necessary to produce the
541 // required quantity of data. For example, if P_SHA256 is being used to
542 // create 80 bytes of data, it will have to be iterated three times
543 // (through A(3)), creating 96 bytes of output data; the last 16 bytes
544 // of the final iteration will then be discarded, leaving 80 bytes of
547 // TLS's PRF is created by applying P_hash to the secret as:
549 // PRF(secret, label, seed) = P_<hash>(secret, label + seed)
551 // The label is an ASCII string.
554 // For cipher suites ending with _SHA256, the PRF is the TLS PRF
555 // with SHA-256 as the hash function.
556 // For cipher suites ending with _SHA384, the PRF is the TLS PRF
557 // with SHA-384 as the hash function.
558 static void prf_hmac_sha256(/*tls_state_t *tls,*/
559 uint8_t *outbuf, unsigned outbuf_size,
560 uint8_t *secret, unsigned secret_size,
562 uint8_t *seed, unsigned seed_size)
564 hmac_precomputed_t pre;
565 uint8_t a[TLS_MAX_MAC_SIZE];
566 uint8_t *out_p = outbuf;
567 unsigned label_size = strlen(label);
568 unsigned MAC_size = SHA256_OUTSIZE;
570 /* In P_hash() calculation, "seed" is "label + seed": */
571 #define SEED label, label_size, seed, seed_size
572 #define A a, MAC_size
574 hmac_begin(&pre, secret, secret_size, sha256_begin);
576 /* A(1) = HMAC_hash(secret, seed) */
577 hmac_sha_precomputed(&pre, a, SEED, NULL);
580 /* HMAC_hash(secret, A(1) + seed) */
581 if (outbuf_size <= MAC_size) {
582 /* Last, possibly incomplete, block */
583 /* (use a[] as temp buffer) */
584 hmac_sha_precomputed(&pre, a, A, SEED, NULL);
585 memcpy(out_p, a, outbuf_size);
588 /* Not last block. Store directly to result buffer */
589 hmac_sha_precomputed(&pre, out_p, A, SEED, NULL);
591 outbuf_size -= MAC_size;
592 /* A(2) = HMAC_hash(secret, A(1)) */
593 hmac_sha_precomputed(&pre, a, A, NULL);
600 static void bad_record_die(tls_state_t *tls, const char *expected, int len)
602 bb_error_msg("got bad TLS record (len:%d) while expecting %s", len, expected);
604 uint8_t *p = tls->inbuf;
606 len = 99; /* don't flood, a few lines should be enough */
608 fprintf(stderr, " %02x", *p++);
616 static void tls_error_die(tls_state_t *tls, int line)
618 dump_tls_record(tls->inbuf, tls->ofs_to_buffered + tls->buffered_size);
619 bb_error_msg_and_die("tls error at line %d cipher:%04x", line, tls->cipher_id);
621 #define tls_error_die(tls) tls_error_die(tls, __LINE__)
624 static void tls_free_inbuf(tls_state_t *tls)
626 if (tls->buffered_size == 0) {
634 static void tls_free_outbuf(tls_state_t *tls)
637 tls->outbuf_size = 0;
641 static void *tls_get_outbuf(tls_state_t *tls, int len)
643 if (len > TLS_MAX_OUTBUF)
645 len += OUTBUF_PFX + OUTBUF_SFX;
646 if (tls->outbuf_size < len) {
647 tls->outbuf_size = len;
648 tls->outbuf = xrealloc(tls->outbuf, len);
650 return tls->outbuf + OUTBUF_PFX;
653 static void *tls_get_zeroed_outbuf(tls_state_t *tls, int len)
655 void *record = tls_get_outbuf(tls, len);
656 memset(record, 0, len);
660 static void xwrite_encrypted_and_hmac_signed(tls_state_t *tls, unsigned size, unsigned type)
662 uint8_t *buf = tls->outbuf + OUTBUF_PFX;
663 struct record_hdr *xhdr;
664 uint8_t padding_length;
666 xhdr = (void*)(buf - RECHDR_LEN);
667 if (!ALLOW_RSA_NULL_SHA256 /* if "no encryption" can't be selected */
668 || tls->cipher_id != TLS_RSA_WITH_NULL_SHA256 /* or if it wasn't selected */
670 xhdr = (void*)(buf - RECHDR_LEN - AES_BLOCK_SIZE); /* place for IV */
674 xhdr->proto_maj = TLS_MAJ;
675 xhdr->proto_min = TLS_MIN;
676 /* fake unencrypted record len for MAC calculation */
677 xhdr->len16_hi = size >> 8;
678 xhdr->len16_lo = size & 0xff;
680 /* Calculate MAC signature */
681 hmac(tls, buf + size, /* result */
682 tls->client_write_MAC_key, tls->MAC_size,
683 &tls->write_seq64_be, sizeof(tls->write_seq64_be),
688 tls->write_seq64_be = SWAP_BE64(1 + SWAP_BE64(tls->write_seq64_be));
690 size += tls->MAC_size;
693 // 6.2.3.1. Null or Standard Stream Cipher
695 // Stream ciphers (including BulkCipherAlgorithm.null; see Appendix A.6)
696 // convert TLSCompressed.fragment structures to and from stream
697 // TLSCiphertext.fragment structures.
699 // stream-ciphered struct {
700 // opaque content[TLSCompressed.length];
701 // opaque MAC[SecurityParameters.mac_length];
702 // } GenericStreamCipher;
704 // The MAC is generated as:
705 // MAC(MAC_write_key, seq_num +
706 // TLSCompressed.type +
707 // TLSCompressed.version +
708 // TLSCompressed.length +
709 // TLSCompressed.fragment);
710 // where "+" denotes concatenation.
712 // The sequence number for this record.
714 // The MAC algorithm specified by SecurityParameters.mac_algorithm.
716 // Note that the MAC is computed before encryption. The stream cipher
717 // encrypts the entire block, including the MAC.
719 // Appendix C. Cipher Suite Definitions
721 // MAC Algorithm mac_length mac_key_length
722 // -------- ----------- ---------- --------------
723 // SHA HMAC-SHA1 20 20
724 // SHA256 HMAC-SHA256 32 32
725 if (ALLOW_RSA_NULL_SHA256
726 && tls->cipher_id == TLS_RSA_WITH_NULL_SHA256
728 /* No encryption, only signing */
729 xhdr->len16_hi = size >> 8;
730 xhdr->len16_lo = size & 0xff;
731 dump_raw_out(">> %s\n", xhdr, RECHDR_LEN + size);
732 xwrite(tls->ofd, xhdr, RECHDR_LEN + size);
733 dbg("wrote %u bytes (NULL crypt, SHA256 hash)\n", size);
737 // 6.2.3.2. CBC Block Cipher
738 // For block ciphers (such as 3DES or AES), the encryption and MAC
739 // functions convert TLSCompressed.fragment structures to and from block
740 // TLSCiphertext.fragment structures.
742 // opaque IV[SecurityParameters.record_iv_length];
743 // block-ciphered struct {
744 // opaque content[TLSCompressed.length];
745 // opaque MAC[SecurityParameters.mac_length];
746 // uint8 padding[GenericBlockCipher.padding_length];
747 // uint8 padding_length;
749 // } GenericBlockCipher;
752 // The Initialization Vector (IV) SHOULD be chosen at random, and
753 // MUST be unpredictable. Note that in versions of TLS prior to 1.1,
754 // there was no IV field (...). For block ciphers, the IV length is
755 // of length SecurityParameters.record_iv_length, which is equal to the
756 // SecurityParameters.block_size.
758 // Padding that is added to force the length of the plaintext to be
759 // an integral multiple of the block cipher's block length.
761 // The padding length MUST be such that the total size of the
762 // GenericBlockCipher structure is a multiple of the cipher's block
763 // length. Legal values range from zero to 255, inclusive.
765 // Appendix C. Cipher Suite Definitions
768 // Cipher Type Material Size Size
769 // ------------ ------ -------- ---- -----
770 // AES_128_CBC Block 16 16 16
771 // AES_256_CBC Block 32 16 16
773 tls_get_random(buf - AES_BLOCK_SIZE, AES_BLOCK_SIZE); /* IV */
774 dbg("before crypt: 5 hdr + %u data + %u hash bytes\n",
775 size - tls->MAC_size, tls->MAC_size);
777 /* Fill IV and padding in outbuf */
778 // RFC is talking nonsense:
779 // "Padding that is added to force the length of the plaintext to be
780 // an integral multiple of the block cipher's block length."
781 // WRONG. _padding+padding_length_, not just _padding_,
783 // IOW: padding_length is the last byte of padding[] array,
784 // contrary to what RFC depicts.
786 // What actually happens is that there is always padding.
787 // If you need one byte to reach BLOCKSIZE, this byte is 0x00.
788 // If you need two bytes, they are both 0x01.
789 // If you need three, they are 0x02,0x02,0x02. And so on.
790 // If you need no bytes to reach BLOCKSIZE, you have to pad a full
791 // BLOCKSIZE with bytes of value (BLOCKSIZE-1).
792 // It's ok to have more than minimum padding, but we do minimum.
793 padding_length = (~size) & (AES_BLOCK_SIZE - 1);
795 buf[size++] = padding_length; /* padding */
796 } while ((size & (AES_BLOCK_SIZE - 1)) != 0);
798 /* Encrypt content+MAC+padding in place */
800 &tls->aes_encrypt, /* selects 128/256 */
801 buf - AES_BLOCK_SIZE, /* IV */
802 buf, size, /* plaintext */
807 dbg("writing 5 + %u IV + %u encrypted bytes, padding_length:0x%02x\n",
808 AES_BLOCK_SIZE, size, padding_length);
809 size += AES_BLOCK_SIZE; /* + IV */
810 xhdr->len16_hi = size >> 8;
811 xhdr->len16_lo = size & 0xff;
812 dump_raw_out(">> %s\n", xhdr, RECHDR_LEN + size);
813 xwrite(tls->ofd, xhdr, RECHDR_LEN + size);
814 dbg("wrote %u bytes\n", (int)RECHDR_LEN + size);
817 /* Example how GCM encryption combines nonce, aad, input and generates
818 * "header | exp_nonce | encrypted output | tag":
819 * nonce:0d 6a 26 31 00 00 00 00 00 00 00 01 (implicit 4 bytes (derived from master secret), then explicit 8 bytes)
820 * aad: 00 00 00 00 00 00 00 01 17 03 03 00 1c
821 * 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)
822 * 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
823 * tag: c2 86 ce 4a 50 4a d0 aa 50 b3 76 5c 49 2a 3f 33
824 * 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
825 * .............................................^^ buf points here
827 static void xwrite_encrypted_aesgcm(tls_state_t *tls, unsigned size, unsigned type)
829 #define COUNTER(v) (*(uint32_t*)(v + 12))
831 uint8_t aad[13 + 3] ALIGNED_long; /* +3 creates [16] buffer, simplifying GHASH() */
832 uint8_t nonce[12 + 4] ALIGNED_long; /* +4 creates space for AES block counter */
833 uint8_t scratch[AES_BLOCK_SIZE] ALIGNED_long; //[16]
834 uint8_t authtag[AES_BLOCK_SIZE] ALIGNED_long; //[16]
836 struct record_hdr *xhdr;
841 buf = tls->outbuf + OUTBUF_PFX; /* see above for the byte it points to */
842 dump_hex("xwrite_encrypted_aesgcm plaintext:%s\n", buf, size);
844 xhdr = (void*)(buf - 8 - RECHDR_LEN);
845 xhdr->type = type; /* do it here so that "type" param no longer used */
851 /* set aad[12], and clear aad[13..15] */
852 COUNTER(aad) = SWAP_LE32(size & 0xff);
854 memcpy(nonce, tls->client_write_IV, 4);
855 t64 = tls->write_seq64_be;
856 move_to_unaligned64(nonce + 4, t64);
857 move_to_unaligned64(aad, t64);
858 move_to_unaligned64(buf - 8, t64);
859 /* seq64 is not used later in this func, can increment here */
860 tls->write_seq64_be = SWAP_BE64(1 + SWAP_BE64(t64));
864 while (remaining != 0) {
868 COUNTER(nonce) = htonl(cnt); /* yes, first cnt here is 2 (!) */
869 aes_encrypt_one_block(&tls->aes_encrypt, nonce, scratch);
870 n = remaining > AES_BLOCK_SIZE ? AES_BLOCK_SIZE : remaining;
871 xorbuf(buf, scratch, n);
876 aesgcm_GHASH(tls->H, aad, /*sizeof(aad),*/ tls->outbuf + OUTBUF_PFX, size, authtag /*, sizeof(authtag)*/);
877 COUNTER(nonce) = htonl(1);
878 aes_encrypt_one_block(&tls->aes_encrypt, nonce, scratch);
879 xorbuf_aligned_AES_BLOCK_SIZE(authtag, scratch);
881 memcpy(buf, authtag, sizeof(authtag));
884 xhdr = (void*)(tls->outbuf + OUTBUF_PFX - 8 - RECHDR_LEN);
885 size += 8 + sizeof(authtag);
886 /*xhdr->type = type; - already is */
887 xhdr->proto_maj = TLS_MAJ;
888 xhdr->proto_min = TLS_MIN;
889 xhdr->len16_hi = size >> 8;
890 xhdr->len16_lo = size & 0xff;
892 dump_raw_out(">> %s\n", xhdr, size);
893 xwrite(tls->ofd, xhdr, size);
894 dbg("wrote %u bytes\n", size);
898 static void xwrite_encrypted(tls_state_t *tls, unsigned size, unsigned type)
900 if (!(tls->flags & ENCRYPTION_AESGCM)) {
901 xwrite_encrypted_and_hmac_signed(tls, size, type);
904 xwrite_encrypted_aesgcm(tls, size, type);
907 static void xwrite_handshake_record(tls_state_t *tls, unsigned size)
909 uint8_t *buf = tls->outbuf + OUTBUF_PFX;
910 struct record_hdr *xhdr = (void*)(buf - RECHDR_LEN);
912 xhdr->type = RECORD_TYPE_HANDSHAKE;
913 xhdr->proto_maj = TLS_MAJ;
914 xhdr->proto_min = TLS_MIN;
915 xhdr->len16_hi = size >> 8;
916 xhdr->len16_lo = size & 0xff;
917 dump_raw_out(">> %s\n", xhdr, RECHDR_LEN + size);
918 xwrite(tls->ofd, xhdr, RECHDR_LEN + size);
919 dbg("wrote %u bytes\n", (int)RECHDR_LEN + size);
922 static void xwrite_and_update_handshake_hash(tls_state_t *tls, unsigned size)
924 if (!(tls->flags & ENCRYPT_ON_WRITE)) {
927 xwrite_handshake_record(tls, size);
928 /* Handshake hash does not include record headers */
929 buf = tls->outbuf + OUTBUF_PFX;
930 hash_handshake(tls, ">> hash:%s", buf, size);
933 xwrite_encrypted(tls, size, RECORD_TYPE_HANDSHAKE);
936 static int tls_has_buffered_record(tls_state_t *tls)
938 int buffered = tls->buffered_size;
939 struct record_hdr *xhdr;
942 if (buffered < RECHDR_LEN)
944 xhdr = (void*)(tls->inbuf + tls->ofs_to_buffered);
945 rec_size = RECHDR_LEN + (0x100 * xhdr->len16_hi + xhdr->len16_lo);
946 if (buffered < rec_size)
951 static const char *alert_text(int code)
954 case 20: return "bad MAC";
955 case 50: return "decode error";
956 case 51: return "decrypt error";
957 case 40: return "handshake failure";
958 case 112: return "unrecognized name";
963 static void tls_aesgcm_decrypt(tls_state_t *tls, uint8_t *buf, int size)
965 #define COUNTER(v) (*(uint32_t*)(v + 12))
967 //uint8_t aad[13 + 3] ALIGNED_long; /* +3 creates [16] buffer, simplifying GHASH() */
968 uint8_t nonce[12 + 4] ALIGNED_long; /* +4 creates space for AES block counter */
969 uint8_t scratch[AES_BLOCK_SIZE] ALIGNED_long; //[16]
970 //uint8_t authtag[AES_BLOCK_SIZE] ALIGNED_long; //[16]
974 //memcpy(aad, buf, 8);
978 //aad[11] = size >> 8;
979 ///* set aad[12], and clear aad[13..15] */
980 //COUNTER(aad) = SWAP_LE32(size & 0xff);
982 memcpy(nonce, tls->server_write_IV, 4);
983 memcpy(nonce + 4, buf, 8);
987 while (remaining != 0) {
991 COUNTER(nonce) = htonl(cnt); /* yes, first cnt here is 2 (!) */
992 aes_encrypt_one_block(&tls->aes_decrypt, nonce, scratch);
993 n = remaining > AES_BLOCK_SIZE ? AES_BLOCK_SIZE : remaining;
994 xorbuf3(buf, scratch, buf + 8, n);
999 //aesgcm_GHASH(tls->H, aad, tls->inbuf + RECHDR_LEN, size, authtag);
1000 //COUNTER(nonce) = htonl(1);
1001 //aes_encrypt_one_block(&tls->aes_encrypt, nonce, scratch);
1002 //xorbuf_aligned_AES_BLOCK_SIZE(authtag, scratch);
1004 //memcmp(buf, authtag, sizeof(authtag)) || DIE("HASH DOES NOT MATCH!");
1008 static int tls_xread_record(tls_state_t *tls, const char *expected)
1010 struct record_hdr *xhdr;
1016 dbg("ofs_to_buffered:%u buffered_size:%u\n", tls->ofs_to_buffered, tls->buffered_size);
1017 total = tls->buffered_size;
1019 memmove(tls->inbuf, tls->inbuf + tls->ofs_to_buffered, total);
1020 //dbg("<< remaining at %d [%d] ", tls->ofs_to_buffered, total);
1021 //dump_raw_in("<< %s\n", tls->inbuf, total);
1028 if (total >= RECHDR_LEN && target == MAX_INBUF) {
1029 xhdr = (void*)tls->inbuf;
1030 target = RECHDR_LEN + (0x100 * xhdr->len16_hi + xhdr->len16_lo);
1032 if (target > MAX_INBUF /* malformed input (too long) */
1033 || xhdr->proto_maj != TLS_MAJ
1034 || xhdr->proto_min != TLS_MIN
1036 sz = total < target ? total : target;
1037 bad_record_die(tls, expected, sz);
1039 dbg("xhdr type:%d ver:%d.%d len:%d\n",
1040 xhdr->type, xhdr->proto_maj, xhdr->proto_min,
1041 0x100 * xhdr->len16_hi + xhdr->len16_lo
1044 /* if total >= target, we have a full packet (and possibly more)... */
1045 if (total - target >= 0)
1047 /* input buffer is grown only as needed */
1048 rem = tls->inbuf_size - total;
1050 tls->inbuf_size += MAX_INBUF / 8;
1051 if (tls->inbuf_size > MAX_INBUF)
1052 tls->inbuf_size = MAX_INBUF;
1053 dbg("inbuf_size:%d\n", tls->inbuf_size);
1054 rem = tls->inbuf_size - total;
1055 tls->inbuf = xrealloc(tls->inbuf, tls->inbuf_size);
1057 sz = safe_read(tls->ifd, tls->inbuf + total, rem);
1059 if (sz == 0 && total == 0) {
1060 /* "Abrupt" EOF, no TLS shutdown (seen from kernel.org) */
1061 dbg("EOF (without TLS shutdown) from peer\n");
1062 tls->buffered_size = 0;
1065 bb_perror_msg_and_die("short read, have only %d", total);
1067 dump_raw_in("<< %s\n", tls->inbuf + total, sz);
1070 tls->buffered_size = total - target;
1071 tls->ofs_to_buffered = target;
1072 //dbg("<< stashing at %d [%d] ", tls->ofs_to_buffered, tls->buffered_size);
1073 //dump_hex("<< %s\n", tls->inbuf + tls->ofs_to_buffered, tls->buffered_size);
1075 sz = target - RECHDR_LEN;
1077 /* Needs to be decrypted? */
1078 if (tls->min_encrypted_len_on_read != 0) {
1079 if (sz < (int)tls->min_encrypted_len_on_read)
1080 bb_error_msg_and_die("bad encrypted len:%u", sz);
1082 if (tls->flags & ENCRYPTION_AESGCM) {
1084 uint8_t *p = tls->inbuf + RECHDR_LEN;
1086 sz -= 8 + AES_BLOCK_SIZE; /* we will overwrite nonce, drop hash */
1087 tls_aesgcm_decrypt(tls, p, sz);
1088 dbg("encrypted size:%u\n", sz);
1090 if (tls->min_encrypted_len_on_read > tls->MAC_size) {
1092 uint8_t *p = tls->inbuf + RECHDR_LEN;
1095 if (sz & (AES_BLOCK_SIZE-1))
1096 bb_error_msg_and_die("bad encrypted len:%u", sz);
1098 /* Decrypt content+MAC+padding, moving it over IV in the process */
1099 sz -= AES_BLOCK_SIZE; /* we will overwrite IV now */
1101 &tls->aes_decrypt, /* selects 128/256 */
1103 p + AES_BLOCK_SIZE, sz, /* ciphertext */
1106 padding_len = p[sz - 1];
1107 dbg("encrypted size:%u type:0x%02x padding_length:0x%02x\n", sz, p[0], padding_len);
1109 sz -= tls->MAC_size + padding_len; /* drop MAC and padding */
1111 /* if nonzero, then it's TLS_RSA_WITH_NULL_SHA256: drop MAC */
1112 /* else: no encryption yet on input, subtract zero = NOP */
1113 sz -= tls->min_encrypted_len_on_read;
1117 bb_error_msg_and_die("encrypted data too short");
1119 //dump_hex("<< %s\n", tls->inbuf, RECHDR_LEN + sz);
1121 xhdr = (void*)tls->inbuf;
1122 if (xhdr->type == RECORD_TYPE_ALERT && sz >= 2) {
1123 uint8_t *p = tls->inbuf + RECHDR_LEN;
1124 dbg("ALERT size:%d level:%d description:%d\n", sz, p[0], p[1]);
1125 if (p[0] == 2) { /* fatal */
1126 bb_error_msg_and_die("TLS %s from peer (alert code %d): %s",
1128 p[1], alert_text(p[1])
1131 if (p[0] == 1) { /* warning */
1132 if (p[1] == 0) { /* "close_notify" warning: it's EOF */
1133 dbg("EOF (TLS encoded) from peer\n");
1137 //This possibly needs to be cached and shown only if
1138 //a fatal alert follows
1139 // bb_error_msg("TLS %s from peer (alert code %d): %s",
1141 // p[1], alert_text(p[1])
1143 /* discard it, get next record */
1146 /* p[0] not 1 or 2: not defined in protocol */
1151 /* RFC 5246 is not saying it explicitly, but sha256 hash
1152 * in our FINISHED record must include data of incoming packets too!
1154 if (tls->inbuf[0] == RECORD_TYPE_HANDSHAKE
1155 /* HANDSHAKE HASH: */
1156 // && do_we_know_which_hash_to_use /* server_hello() might not know it in the future! */
1158 hash_handshake(tls, "<< hash:%s", tls->inbuf + RECHDR_LEN, sz);
1161 dbg("got block len:%u\n", sz);
1165 static void binary_to_pstm(pstm_int *pstm_n, uint8_t *bin_ptr, unsigned len)
1167 pstm_init_for_read_unsigned_bin(/*pool:*/ NULL, pstm_n, len);
1168 pstm_read_unsigned_bin(pstm_n, bin_ptr, len);
1169 //return bin_ptr + len;
1173 * DER parsing routines
1175 static unsigned get_der_len(uint8_t **bodyp, uint8_t *der, uint8_t *end)
1181 // if ((der[0] & 0x1f) == 0x1f) /* not single-byte item code? */
1184 len = der[1]; /* maybe it's short len */
1188 if (len == 0x80 || end - der < (int)(len - 0x7e)) {
1189 /* 0x80 is "0 bytes of len", invalid DER: must use short len if can */
1190 /* need 3 or 4 bytes for 81, 82 */
1194 len1 = der[2]; /* if (len == 0x81) it's "ii 81 xx", fetch xx */
1196 /* >0x82 is "3+ bytes of len", should not happen realistically */
1199 if (len == 0x82) { /* it's "ii 82 xx yy" */
1200 len1 = 0x100*len1 + der[3];
1201 der += 1; /* skip [yy] */
1203 der += 1; /* skip [xx] */
1206 // xfunc_die(); /* invalid DER: must use short len if can */
1208 der += 2; /* skip [code]+[1byte] */
1210 if (end - der < (int)len)
1217 static uint8_t *enter_der_item(uint8_t *der, uint8_t **endp)
1220 unsigned len = get_der_len(&new_der, der, *endp);
1221 dbg_der("entered der @%p:0x%02x len:%u inner_byte @%p:0x%02x\n", der, der[0], len, new_der, new_der[0]);
1222 /* Move "end" position to cover only this item */
1223 *endp = new_der + len;
1227 static uint8_t *skip_der_item(uint8_t *der, uint8_t *end)
1230 unsigned len = get_der_len(&new_der, der, end);
1233 dbg_der("skipped der 0x%02x, next byte 0x%02x\n", der[0], new_der[0]);
1237 static void der_binary_to_pstm(pstm_int *pstm_n, uint8_t *der, uint8_t *end)
1240 unsigned len = get_der_len(&bin_ptr, der, end);
1242 dbg_der("binary bytes:%u, first:0x%02x\n", len, bin_ptr[0]);
1243 binary_to_pstm(pstm_n, bin_ptr, len);
1246 static void find_key_in_der_cert(tls_state_t *tls, uint8_t *der, int len)
1248 /* Certificate is a DER-encoded data structure. Each DER element has a length,
1249 * which makes it easy to skip over large compound elements of any complexity
1250 * without parsing them. Example: partial decode of kernel.org certificate:
1251 * SEQ 0x05ac/1452 bytes (Certificate): 308205ac
1252 * SEQ 0x0494/1172 bytes (tbsCertificate): 30820494
1253 * [ASN_CONTEXT_SPECIFIC | ASN_CONSTRUCTED | 0] 3 bytes: a003
1254 * INTEGER (version): 0201 02
1255 * INTEGER 0x11 bytes (serialNumber): 0211 00 9f85bf664b0cddafca508679501b2be4
1256 * //^^^^^^note: matrixSSL also allows [ASN_CONTEXT_SPECIFIC | ASN_PRIMITIVE | 2] = 0x82 type
1257 * SEQ 0x0d bytes (signatureAlgo): 300d
1258 * OID 9 bytes: 0609 2a864886f70d01010b (OID_SHA256_RSA_SIG 42.134.72.134.247.13.1.1.11)
1260 * SEQ 0x5f bytes (issuer): 305f
1261 * SET 11 bytes: 310b
1263 * OID 3 bytes: 0603 550406
1264 * Printable string "FR": 1302 4652
1265 * SET 14 bytes: 310e
1266 * SEQ 12 bytes: 300c
1267 * OID 3 bytes: 0603 550408
1268 * Printable string "Paris": 1305 5061726973
1269 * SET 14 bytes: 310e
1270 * SEQ 12 bytes: 300c
1271 * OID 3 bytes: 0603 550407
1272 * Printable string "Paris": 1305 5061726973
1273 * SET 14 bytes: 310e
1274 * SEQ 12 bytes: 300c
1275 * OID 3 bytes: 0603 55040a
1276 * Printable string "Gandi": 1305 47616e6469
1277 * SET 32 bytes: 3120
1278 * SEQ 30 bytes: 301e
1279 * OID 3 bytes: 0603 550403
1280 * Printable string "Gandi Standard SSL CA 2": 1317 47616e6469205374616e646172642053534c2043412032
1281 * SEQ 30 bytes (validity): 301e
1282 * TIME "161011000000Z": 170d 3136313031313030303030305a
1283 * TIME "191011235959Z": 170d 3139313031313233353935395a
1284 * SEQ 0x5b/91 bytes (subject): 305b //I did not decode this
1285 * 3121301f060355040b1318446f6d61696e20436f
1286 * 6e74726f6c2056616c6964617465643121301f06
1287 * 0355040b1318506f73697469766553534c204d75
1288 * 6c74692d446f6d61696e31133011060355040313
1289 * 0a6b65726e656c2e6f7267
1290 * SEQ 0x01a2/418 bytes (subjectPublicKeyInfo): 308201a2
1291 * SEQ 13 bytes (algorithm): 300d
1292 * OID 9 bytes: 0609 2a864886f70d010101 (OID_RSA_KEY_ALG 42.134.72.134.247.13.1.1.1)
1294 * BITSTRING 0x018f/399 bytes (publicKey): 0382018f
1296 * //after the zero byte, it appears key itself uses DER encoding:
1297 * SEQ 0x018a/394 bytes: 3082018a
1298 * INTEGER 0x0181/385 bytes (modulus): 02820181
1299 * 00b1ab2fc727a3bef76780c9349bf3
1300 * ...24 more blocks of 15 bytes each...
1301 * 90e895291c6bc8693b65
1302 * INTEGER 3 bytes (exponent): 0203 010001
1303 * [ASN_CONTEXT_SPECIFIC | ASN_CONSTRUCTED | 0x3] 0x01e5 bytes (X509v3 extensions): a38201e5
1304 * SEQ 0x01e1 bytes: 308201e1
1306 * Certificate is a sequence of three elements:
1307 * tbsCertificate (SEQ)
1308 * signatureAlgorithm (AlgorithmIdentifier)
1309 * signatureValue (BIT STRING)
1311 * In turn, tbsCertificate is a sequence of:
1314 * signatureAlgo (AlgorithmIdentifier)
1315 * issuer (Name, has complex structure)
1316 * validity (Validity, SEQ of two Times)
1318 * subjectPublicKeyInfo (SEQ)
1321 * subjectPublicKeyInfo is a sequence of:
1322 * algorithm (AlgorithmIdentifier)
1323 * publicKey (BIT STRING)
1325 * We need Certificate.tbsCertificate.subjectPublicKeyInfo.publicKey
1327 * Example of an ECDSA key:
1328 * SEQ 0x59 bytes (subjectPublicKeyInfo): 3059
1329 * SEQ 0x13 bytes (algorithm): 3013
1330 * OID 7 bytes: 0607 2a8648ce3d0201 (OID_ECDSA_KEY_ALG 42.134.72.206.61.2.1)
1331 * OID 8 bytes: 0608 2a8648ce3d030107 (OID_EC_prime256v1 42.134.72.206.61.3.1.7)
1332 * BITSTRING 0x42 bytes (publicKey): 0342
1333 * 0004 53af f65e 50cc 7959 7e29 0171 c75c
1334 * 7335 e07d f45b 9750 b797 3a38 aebb 2ac6
1335 * 8329 2748 e77e 41cb d482 2ce6 05ec a058
1336 * f3ab d561 2f4c d845 9ad3 7252 e3de bd3b
1339 uint8_t *end = der + len;
1341 /* enter "Certificate" item: [der, end) will be only Cert */
1342 der = enter_der_item(der, &end);
1344 /* enter "tbsCertificate" item: [der, end) will be only tbsCert */
1345 der = enter_der_item(der, &end);
1348 * Skip version field only if it is present. For a v1 certificate, the
1349 * version field won't be present since v1 is the default value for the
1350 * version field and fields with default values should be omitted (see
1351 * RFC 5280 sections 4.1 and 4.1.2.1). If the version field is present
1352 * it will have a tag class of 2 (context-specific), bit 6 as 1
1353 * (constructed), and a tag number of 0 (see ITU-T X.690 sections 8.1.2
1358 /* bits 4-0: 00000 */
1360 der = skip_der_item(der, end); /* version */
1362 /* skip up to subjectPublicKeyInfo */
1363 der = skip_der_item(der, end); /* serialNumber */
1364 der = skip_der_item(der, end); /* signatureAlgo */
1365 der = skip_der_item(der, end); /* issuer */
1366 der = skip_der_item(der, end); /* validity */
1367 der = skip_der_item(der, end); /* subject */
1369 /* enter subjectPublicKeyInfo */
1370 der = enter_der_item(der, &end);
1371 { /* check subjectPublicKeyInfo.algorithm */
1372 static const uint8_t OID_RSA_KEY_ALG[] = {
1373 0x30,0x0d, // SEQ 13 bytes
1374 0x06,0x09, 0x2a,0x86,0x48,0x86,0xf7,0x0d,0x01,0x01,0x01, //OID_RSA_KEY_ALG 42.134.72.134.247.13.1.1.1
1375 //0x05,0x00, // NULL
1377 static const uint8_t OID_ECDSA_KEY_ALG[] = {
1378 0x30,0x13, // SEQ 0x13 bytes
1379 0x06,0x07, 0x2a,0x86,0x48,0xce,0x3d,0x02,0x01, //OID_ECDSA_KEY_ALG 42.134.72.206.61.2.1
1380 //allow any curve code for now...
1381 // 0x06,0x08, 0x2a,0x86,0x48,0xce,0x3d,0x03,0x01,0x07, //OID_EC_prime256v1 42.134.72.206.61.3.1.7
1383 //42.134.72.206.61.3 is ellipticCurve
1384 //42.134.72.206.61.3.0 is c-TwoCurve
1385 //42.134.72.206.61.3.1 is primeCurve
1386 //42.134.72.206.61.3.1.7 is curve_secp256r1
1388 if (memcmp(der, OID_RSA_KEY_ALG, sizeof(OID_RSA_KEY_ALG)) == 0) {
1390 tls->flags |= GOT_CERT_RSA_KEY_ALG;
1392 if (memcmp(der, OID_ECDSA_KEY_ALG, sizeof(OID_ECDSA_KEY_ALG)) == 0) {
1394 //UNUSED: tls->flags |= GOT_CERT_ECDSA_KEY_ALG;
1396 bb_error_msg_and_die("not RSA or ECDSA cert");
1399 if (tls->flags & GOT_CERT_RSA_KEY_ALG) {
1400 /* parse RSA key: */
1401 //based on getAsnRsaPubKey(), pkcs1ParsePrivBin() is also of note
1402 /* skip subjectPublicKeyInfo.algorithm */
1403 der = skip_der_item(der, end);
1404 /* enter subjectPublicKeyInfo.publicKey */
1405 //die_if_not_this_der_type(der, end, 0x03); /* must be BITSTRING */
1406 der = enter_der_item(der, &end);
1408 dbg("key bytes:%u, first:0x%02x\n", (int)(end - der), der[0]);
1413 * SEQ 0x018a/394 bytes: 3082018a
1414 * INTEGER 0x0181/385 bytes (modulus): 02820181 XX...XXX
1415 * INTEGER 3 bytes (exponent): 0203 010001
1417 if (*der != 0) /* "ignore bits", should be 0 */
1420 der = enter_der_item(der, &end); /* enter SEQ */
1421 /* memset(tls->hsd->server_rsa_pub_key, 0, sizeof(tls->hsd->server_rsa_pub_key)); - already is */
1422 der_binary_to_pstm(&tls->hsd->server_rsa_pub_key.N, der, end); /* modulus */
1423 der = skip_der_item(der, end);
1424 der_binary_to_pstm(&tls->hsd->server_rsa_pub_key.e, der, end); /* exponent */
1425 tls->hsd->server_rsa_pub_key.size = pstm_unsigned_bin_size(&tls->hsd->server_rsa_pub_key.N);
1426 dbg("server_rsa_pub_key.size:%d\n", tls->hsd->server_rsa_pub_key.size);
1428 /* else: ECDSA key. It is not used for generating encryption keys,
1429 * it is used only to sign the EC public key (which comes in ServerKey message).
1430 * Since we do not verify cert validity, verifying signature on EC public key
1431 * wouldn't add any security. Thus, we do nothing here.
1436 * TLS Handshake routines
1438 static int tls_xread_handshake_block(tls_state_t *tls, int min_len)
1440 struct record_hdr *xhdr;
1441 int len = tls_xread_record(tls, "handshake record");
1443 xhdr = (void*)tls->inbuf;
1445 || xhdr->type != RECORD_TYPE_HANDSHAKE
1447 bad_record_die(tls, "handshake record", len);
1449 dbg("got HANDSHAKE\n");
1453 static ALWAYS_INLINE void fill_handshake_record_hdr(void *buf, unsigned type, unsigned len)
1455 struct handshake_hdr {
1457 uint8_t len24_hi, len24_mid, len24_lo;
1462 h->len24_hi = len >> 16;
1463 h->len24_mid = len >> 8;
1464 h->len24_lo = len & 0xff;
1467 static void send_client_hello_and_alloc_hsd(tls_state_t *tls, const char *sni)
1469 #define NUM_CIPHERS (13 + ALLOW_RSA_NULL_SHA256)
1470 static const uint8_t ciphers[] = {
1471 0x00,(1 + NUM_CIPHERS) * 2, //len16_be
1472 0x00,0xFF, //not a cipher - TLS_EMPTY_RENEGOTIATION_INFO_SCSV
1473 /* ^^^^^^ RFC 5746 Renegotiation Indication Extension - some servers will refuse to work with us otherwise */
1474 0xC0,0x09, // 1 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA - ok: wget https://is.gd/
1475 0xC0,0x0A, // 2 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA - ok: wget https://is.gd/
1476 0xC0,0x13, // 3 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-SHA
1477 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)
1478 0xC0,0x23, // 5 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 - ok: wget https://is.gd/
1479 // 0xC0,0x24, // TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
1480 0xC0,0x27, // 6 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-SHA256
1481 // 0xC0,0x28, // TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
1482 0xC0,0x2B, // 7 TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 - ok: wget https://is.gd/
1483 // 0xC0,0x2C, // TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 - wget https://is.gd/: "TLS error from peer (alert code 20): bad MAC"
1484 //TODO: GCM_SHA384 ciphers can be supported, only need sha384-based PRF?
1485 0xC0,0x2F, // 8 TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-GCM-SHA256
1486 // 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"
1487 //possibly these too:
1488 // 0xC0,0x35, // TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA
1489 // 0xC0,0x36, // TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA
1490 // 0xC0,0x37, // TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256
1491 // 0xC0,0x38, // TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
1492 0x00,0x2F, // 9 TLS_RSA_WITH_AES_128_CBC_SHA - ok: openssl s_server ... -cipher AES128-SHA
1493 0x00,0x35, //10 TLS_RSA_WITH_AES_256_CBC_SHA - ok: openssl s_server ... -cipher AES256-SHA
1494 0x00,0x3C, //11 TLS_RSA_WITH_AES_128_CBC_SHA256 - ok: openssl s_server ... -cipher AES128-SHA256
1495 0x00,0x3D, //12 TLS_RSA_WITH_AES_256_CBC_SHA256 - ok: openssl s_server ... -cipher AES256-SHA256
1496 0x00,0x9C, //13 TLS_RSA_WITH_AES_128_GCM_SHA256 - ok: openssl s_server ... -cipher AES128-GCM-SHA256
1497 // 0x00,0x9D, // TLS_RSA_WITH_AES_256_GCM_SHA384 - openssl s_server ... -cipher AES256-GCM-SHA384: "decryption failed or bad record mac"
1498 #if ALLOW_RSA_NULL_SHA256
1499 0x00,0x3B, // TLS_RSA_WITH_NULL_SHA256
1501 0x01,0x00, //not a cipher - comprtypes_len, comprtype
1503 static const uint8_t supported_groups[] = {
1504 0x00,0x0a, //extension_type: "supported_groups"
1505 0x00,0x04, //ext len
1506 0x00,0x02, //list len
1507 0x00,0x1d, //curve_x25519 (RFC 7748)
1508 //0x00,0x17, //curve_secp256r1
1509 //0x00,0x18, //curve_secp384r1
1510 //0x00,0x19, //curve_secp521r1
1512 //static const uint8_t signature_algorithms[] = {
1516 // 0601 0602 0603 0501 0502 0503 0401 0402 0403 0301 0302 0303 0201 0202 0203
1519 struct client_hello {
1521 uint8_t len24_hi, len24_mid, len24_lo;
1522 uint8_t proto_maj, proto_min;
1524 uint8_t session_id_len;
1525 /* uint8_t session_id[]; */
1526 uint8_t cipherid_len16_hi, cipherid_len16_lo;
1527 uint8_t cipherid[(1 + NUM_CIPHERS) * 2]; /* actually variable */
1528 uint8_t comprtypes_len;
1529 uint8_t comprtypes[1]; /* actually variable */
1530 /* Extensions (SNI shown):
1531 * hi,lo // len of all extensions
1532 * 00,00 // extension_type: "Server Name"
1533 * 00,0e // list len (there can be more than one SNI)
1534 * 00,0c // len of 1st Server Name Indication
1535 * 00 // name type: host_name
1537 * "localhost" // name
1539 // GNU Wget 1.18 to cdn.kernel.org sends these extensions:
1541 // 0005 0005 0100000000 - status_request
1542 // 0000 0013 0011 00 000e 63646e 2e 6b65726e656c 2e 6f7267 - server_name
1543 // ff01 0001 00 - renegotiation_info
1544 // 0023 0000 - session_ticket
1545 // 000a 0008 0006001700180019 - supported_groups
1546 // 000b 0002 0100 - ec_point_formats
1547 // 000d 0016 0014 0401 0403 0501 0503 0601 0603 0301 0303 0201 0203 - signature_algorithms
1548 // wolfssl library sends this option, RFC 7627 (closes a security weakness, some servers may require it. TODO?):
1549 // 0017 0000 - extended master secret
1551 struct client_hello *record;
1555 int sni_len = sni ? strnlen(sni, 127 - 5) : 0;
1558 /* is.gd responds with "handshake failure" to our hello if there's no supported_groups element */
1559 ext_len += sizeof(supported_groups);
1561 ext_len += 9 + sni_len;
1563 /* +2 is for "len of all extensions" 2-byte field */
1564 len = sizeof(*record) + 2 + ext_len;
1565 record = tls_get_zeroed_outbuf(tls, len);
1567 fill_handshake_record_hdr(record, HANDSHAKE_CLIENT_HELLO, len);
1568 record->proto_maj = TLS_MAJ; /* the "requested" version of the protocol, */
1569 record->proto_min = TLS_MIN; /* can be higher than one in record headers */
1570 tls_get_random(record->rand32, sizeof(record->rand32));
1571 if (TLS_DEBUG_FIXED_SECRETS)
1572 memset(record->rand32, 0x11, sizeof(record->rand32));
1573 /* record->session_id_len = 0; - already is */
1575 BUILD_BUG_ON(sizeof(ciphers) != 2 + (1 + NUM_CIPHERS) * 2 + 2);
1576 memcpy(&record->cipherid_len16_hi, ciphers, sizeof(ciphers));
1578 ptr = (void*)(record + 1);
1579 *ptr++ = ext_len >> 8;
1583 //ptr[1] = 0; //extension_type
1585 ptr[3] = sni_len + 5; //list len
1587 ptr[5] = sni_len + 3; //len of 1st SNI
1588 //ptr[6] = 0; //name type
1590 ptr[8] = sni_len; //name len
1591 ptr = mempcpy(&ptr[9], sni, sni_len);
1593 memcpy(ptr, supported_groups, sizeof(supported_groups));
1595 tls->hsd = xzalloc(sizeof(*tls->hsd));
1596 /* HANDSHAKE HASH: ^^^ + len if need to save saved_client_hello */
1597 memcpy(tls->hsd->client_and_server_rand32, record->rand32, sizeof(record->rand32));
1599 tls->hsd->saved_client_hello_size = len;
1600 memcpy(tls->hsd->saved_client_hello, record, len);
1602 dbg(">> CLIENT_HELLO\n");
1603 /* Can hash immediately only if we know which MAC hash to use.
1604 * So far we do know: it's sha256:
1606 sha256_begin(&tls->hsd->handshake_hash_ctx);
1607 xwrite_and_update_handshake_hash(tls, len);
1608 /* if this would become infeasible: save tls->hsd->saved_client_hello,
1609 * use "xwrite_handshake_record(tls, len)" here,
1610 * and hash saved_client_hello later.
1614 static void get_server_hello(tls_state_t *tls)
1616 struct server_hello {
1617 struct record_hdr xhdr;
1619 uint8_t len24_hi, len24_mid, len24_lo;
1620 uint8_t proto_maj, proto_min;
1621 uint8_t rand32[32]; /* first 4 bytes are unix time in BE format */
1622 uint8_t session_id_len;
1623 uint8_t session_id[32];
1624 uint8_t cipherid_hi, cipherid_lo;
1626 /* extensions may follow, but only those which client offered in its Hello */
1629 struct server_hello *hp;
1634 len = tls_xread_handshake_block(tls, 74 - 32);
1636 hp = (void*)tls->inbuf;
1638 // 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|
1639 //SvHl len=70 maj.min unixtime^^^ 28randbytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^_^^^ slen sid32bytes^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cipSel comprSel
1640 if (hp->type != HANDSHAKE_SERVER_HELLO
1641 || hp->len24_hi != 0
1642 || hp->len24_mid != 0
1643 /* hp->len24_lo checked later */
1644 || hp->proto_maj != TLS_MAJ
1645 || hp->proto_min != TLS_MIN
1647 bad_record_die(tls, "'server hello'", len);
1650 cipherid = &hp->cipherid_hi;
1651 len24 = hp->len24_lo;
1652 if (hp->session_id_len != 32) {
1653 if (hp->session_id_len != 0)
1654 bad_record_die(tls, "'server hello'", len);
1656 // session_id_len == 0: no session id
1658 // may return an empty session_id to indicate that the session will
1659 // not be cached and therefore cannot be resumed."
1661 len24 += 32; /* what len would be if session id would be present */
1665 bad_record_die(tls, "'server hello'", len);
1666 dbg("<< SERVER_HELLO\n");
1668 memcpy(tls->hsd->client_and_server_rand32 + 32, hp->rand32, sizeof(hp->rand32));
1670 /* Set up encryption params based on selected cipher */
1672 0xC0,0x09, // 1 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA - ok: wget https://is.gd/
1673 0xC0,0x0A, // 2 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA - ok: wget https://is.gd/
1674 0xC0,0x13, // 3 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-SHA
1675 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)
1676 0xC0,0x23, // 5 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 - ok: wget https://is.gd/
1677 // 0xC0,0x24, // TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
1678 0xC0,0x27, // 6 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-SHA256
1679 // 0xC0,0x28, // TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
1680 0xC0,0x2B, // 7 TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 - ok: wget https://is.gd/
1681 // 0xC0,0x2C, // TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 - wget https://is.gd/: "TLS error from peer (alert code 20): bad MAC"
1682 0xC0,0x2F, // 8 TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 - ok: openssl s_server ... -cipher ECDHE-RSA-AES128-GCM-SHA256
1683 // 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"
1684 //possibly these too:
1685 // 0xC0,0x35, // TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA
1686 // 0xC0,0x36, // TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA
1687 // 0xC0,0x37, // TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256
1688 // 0xC0,0x38, // TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384 - can't do SHA384 yet
1689 0x00,0x2F, // 9 TLS_RSA_WITH_AES_128_CBC_SHA - ok: openssl s_server ... -cipher AES128-SHA
1690 0x00,0x35, //10 TLS_RSA_WITH_AES_256_CBC_SHA - ok: openssl s_server ... -cipher AES256-SHA
1691 0x00,0x3C, //11 TLS_RSA_WITH_AES_128_CBC_SHA256 - ok: openssl s_server ... -cipher AES128-SHA256
1692 0x00,0x3D, //12 TLS_RSA_WITH_AES_256_CBC_SHA256 - ok: openssl s_server ... -cipher AES256-SHA256
1693 0x00,0x9C, //13 TLS_RSA_WITH_AES_128_GCM_SHA256 - ok: openssl s_server ... -cipher AES128-GCM-SHA256
1694 // 0x00,0x9D, // TLS_RSA_WITH_AES_256_GCM_SHA384 - openssl s_server ... -cipher AES256-GCM-SHA384: "decryption failed or bad record mac"
1695 0x00,0x3B, // TLS_RSA_WITH_NULL_SHA256
1697 cipherid1 = cipherid[1];
1698 tls->cipher_id = 0x100 * cipherid[0] + cipherid1;
1699 tls->key_size = AES256_KEYSIZE;
1700 tls->MAC_size = SHA256_OUTSIZE;
1701 /*tls->IV_size = 0; - already is */
1702 if (cipherid[0] == 0xC0) {
1703 /* All C0xx are ECDHE */
1704 tls->flags |= NEED_EC_KEY;
1705 if (cipherid1 & 1) {
1706 /* Odd numbered C0xx use AES128 (even ones use AES256) */
1707 tls->key_size = AES128_KEYSIZE;
1709 if (cipherid1 <= 0x14) {
1710 tls->MAC_size = SHA1_OUTSIZE;
1712 if (cipherid1 >= 0x2B && cipherid1 <= 0x30) {
1713 /* C02B,2C,2F,30 are AES-GCM */
1714 tls->flags |= ENCRYPTION_AESGCM;
1719 /* All 00xx are RSA */
1720 if (cipherid1 == 0x2F
1721 || cipherid1 == 0x3C
1722 || cipherid1 == 0x9C
1724 tls->key_size = AES128_KEYSIZE;
1726 if (cipherid1 <= 0x35) {
1727 tls->MAC_size = SHA1_OUTSIZE;
1729 if (cipherid1 == 0x9C /*|| cipherid1 == 0x9D*/) {
1730 /* 009C,9D are AES-GCM */
1731 tls->flags |= ENCRYPTION_AESGCM;
1736 dbg("server chose cipher %04x\n", tls->cipher_id);
1737 dbg("key_size:%u MAC_size:%u IV_size:%u\n", tls->key_size, tls->MAC_size, tls->IV_size);
1739 /* Handshake hash eventually destined to FINISHED record
1740 * is sha256 regardless of cipher
1741 * (at least for all ciphers defined by RFC5246).
1742 * It's not sha1 for AES_128_CBC_SHA - only MAC is sha1, not this hash.
1745 sha256_begin(&tls->hsd->handshake_hash_ctx);
1746 hash_handshake(tls, ">> client hello hash:%s",
1747 tls->hsd->saved_client_hello, tls->hsd->saved_client_hello_size
1749 hash_handshake(tls, "<< server hello hash:%s",
1750 tls->inbuf + RECHDR_LEN, len
1755 static void get_server_cert(tls_state_t *tls)
1757 struct record_hdr *xhdr;
1761 len = tls_xread_handshake_block(tls, 10);
1763 xhdr = (void*)tls->inbuf;
1764 certbuf = (void*)(xhdr + 1);
1765 if (certbuf[0] != HANDSHAKE_CERTIFICATE)
1766 bad_record_die(tls, "certificate", len);
1767 dbg("<< CERTIFICATE\n");
1769 // 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...
1770 //Cert len=4388 ChainLen CertLen^ DER encoded X509 starts here. openssl x509 -in FILE -inform DER -noout -text
1771 len1 = get24be(certbuf + 1);
1772 if (len1 > len - 4) tls_error_die(tls);
1774 len1 = get24be(certbuf + 4);
1775 if (len1 > len - 3) tls_error_die(tls);
1777 len1 = get24be(certbuf + 7);
1778 if (len1 > len - 3) tls_error_die(tls);
1782 find_key_in_der_cert(tls, certbuf + 10, len);
1785 /* On input, len is known to be >= 4.
1786 * The record is known to be SERVER_KEY_EXCHANGE.
1788 static void process_server_key(tls_state_t *tls, int len)
1790 struct record_hdr *xhdr;
1795 xhdr = (void*)tls->inbuf;
1796 keybuf = (void*)(xhdr + 1);
1797 //seen from is.gd: it selects curve_x25519:
1798 // 0c 00006e //SERVER_KEY_EXCHANGE, len
1799 // 03 //curve_type: named curve
1800 // 001d //curve_x25519
1801 //server-chosen EC point, and then signed_params
1802 // (RFC 8422: "A hash of the params, with the signature
1803 // appropriate to that hash applied. The private key corresponding
1804 // to the certified public key in the server's Certificate message is
1805 // used for signing.")
1806 //follow. Format unclear/guessed:
1807 // 20 //eccPubKeyLen
1808 // 25511923d73b70dd2f60e66ba2f3fda31a9c25170963c7a3a972e481dbb2835d //eccPubKey (32bytes)
1809 // 0203 //hashSigAlg: 2:SHA1 (4:SHA256 5:SHA384 6:SHA512), 3:ECDSA (1:RSA)
1810 // 0046 //len (16bit)
1812 // 02 20 //INTEGER, len
1813 // 2e18e7c2a9badd0a70cd3059a6ab114539b9f5163568911147386cd77ed7c412 //32bytes
1814 //this item ^^^^^ is sometimes 33 bytes (with all container sizes also +1)
1815 // 02 20 //INTEGER, len
1816 // 64523d6216cb94c43c9b20e377d8c52c55be6703fd6730a155930c705eaf3af6 //32bytes
1817 //same about this item ^^^^^
1819 //seen from ftp.openbsd.org
1820 //(which only accepts ECDHE-RSA-AESnnn-GCM-SHAnnn and ECDHE-RSA-CHACHA20-POLY1305 ciphers):
1821 // 0c 000228 //SERVER_KEY_EXCHANGE, len
1822 // 03 //curve_type: named curve
1823 // 001d //curve_x25519
1824 // 20 //eccPubKeyLen
1825 // eef7a15c43b71a4c7eaa48a39369399cc4332e569ec90a83274cc92596705c1a //eccPubKey
1826 // 0401 //hashSigAlg: 4:SHA256, 1:RSA
1828 // //0x200 bytes follow
1830 /* Get and verify length */
1831 len1 = get24be(keybuf + 1);
1832 if (len1 > len - 4) tls_error_die(tls);
1834 if (len < (1+2+1+32)) tls_error_die(tls);
1837 /* So far we only support curve_x25519 */
1838 move_from_unaligned32(t32, keybuf);
1839 if (t32 != htonl(0x03001d20))
1840 bb_error_msg_and_die("elliptic curve is not x25519");
1842 memcpy(tls->hsd->ecc_pub_key32, keybuf + 4, 32);
1843 tls->flags |= GOT_EC_KEY;
1844 dbg("got eccPubKey\n");
1847 static void send_empty_client_cert(tls_state_t *tls)
1849 struct client_empty_cert {
1851 uint8_t len24_hi, len24_mid, len24_lo;
1852 uint8_t cert_chain_len24_hi, cert_chain_len24_mid, cert_chain_len24_lo;
1854 struct client_empty_cert *record;
1856 record = tls_get_zeroed_outbuf(tls, sizeof(*record));
1857 //fill_handshake_record_hdr(record, HANDSHAKE_CERTIFICATE, sizeof(*record));
1858 //record->cert_chain_len24_hi = 0;
1859 //record->cert_chain_len24_mid = 0;
1860 //record->cert_chain_len24_lo = 0;
1862 record->type = HANDSHAKE_CERTIFICATE;
1863 record->len24_lo = 3;
1865 dbg(">> CERTIFICATE\n");
1866 xwrite_and_update_handshake_hash(tls, sizeof(*record));
1869 static void send_client_key_exchange(tls_state_t *tls)
1871 struct client_key_exchange {
1873 uint8_t len24_hi, len24_mid, len24_lo;
1874 uint8_t key[2 + 4 * 1024]; // size??
1876 //FIXME: better size estimate
1877 struct client_key_exchange *record = tls_get_zeroed_outbuf(tls, sizeof(*record));
1878 uint8_t rsa_premaster[RSA_PREMASTER_SIZE];
1879 uint8_t x25519_premaster[CURVE25519_KEYSIZE];
1884 if (!(tls->flags & NEED_EC_KEY)) {
1886 if (!(tls->flags & GOT_CERT_RSA_KEY_ALG))
1887 bb_error_msg("server cert is not RSA");
1889 tls_get_random(rsa_premaster, sizeof(rsa_premaster));
1890 if (TLS_DEBUG_FIXED_SECRETS)
1891 memset(rsa_premaster, 0x44, sizeof(rsa_premaster));
1893 // "Note: The version number in the PreMasterSecret is the version
1894 // offered by the client in the ClientHello.client_version, not the
1895 // version negotiated for the connection."
1896 rsa_premaster[0] = TLS_MAJ;
1897 rsa_premaster[1] = TLS_MIN;
1898 dump_hex("premaster:%s\n", rsa_premaster, sizeof(rsa_premaster));
1899 len = psRsaEncryptPub(/*pool:*/ NULL,
1900 /* psRsaKey_t* */ &tls->hsd->server_rsa_pub_key,
1901 rsa_premaster, /*inlen:*/ sizeof(rsa_premaster),
1902 record->key + 2, sizeof(record->key) - 2,
1905 /* keylen16 exists for RSA (in TLS, not in SSL), but not for some other key types */
1906 record->key[0] = len >> 8;
1907 record->key[1] = len & 0xff;
1909 premaster = rsa_premaster;
1910 premaster_size = sizeof(rsa_premaster);
1913 static const uint8_t basepoint9[CURVE25519_KEYSIZE] = {9};
1914 uint8_t privkey[CURVE25519_KEYSIZE]; //[32]
1916 if (!(tls->flags & GOT_EC_KEY))
1917 bb_error_msg("server did not provide EC key");
1919 /* Generate random private key, see RFC 7748 */
1920 tls_get_random(privkey, sizeof(privkey));
1922 privkey[CURVE25519_KEYSIZE-1] = ((privkey[CURVE25519_KEYSIZE-1] & 0x7f) | 0x40);
1924 /* Compute public key */
1925 curve25519(record->key + 1, privkey, basepoint9);
1927 /* Compute premaster using peer's public key */
1928 dbg("computing x25519_premaster\n");
1929 curve25519(x25519_premaster, privkey, tls->hsd->ecc_pub_key32);
1931 len = CURVE25519_KEYSIZE;
1932 record->key[0] = len;
1934 premaster = x25519_premaster;
1935 premaster_size = sizeof(x25519_premaster);
1938 record->type = HANDSHAKE_CLIENT_KEY_EXCHANGE;
1939 /* record->len24_hi = 0; - already is */
1940 record->len24_mid = len >> 8;
1941 record->len24_lo = len & 0xff;
1944 dbg(">> CLIENT_KEY_EXCHANGE\n");
1945 xwrite_and_update_handshake_hash(tls, len);
1948 // For all key exchange methods, the same algorithm is used to convert
1949 // the pre_master_secret into the master_secret. The pre_master_secret
1950 // should be deleted from memory once the master_secret has been
1952 // master_secret = PRF(pre_master_secret, "master secret",
1953 // ClientHello.random + ServerHello.random)
1955 // The master secret is always exactly 48 bytes in length. The length
1956 // of the premaster secret will vary depending on key exchange method.
1957 prf_hmac_sha256(/*tls,*/
1958 tls->hsd->master_secret, sizeof(tls->hsd->master_secret),
1959 premaster, premaster_size,
1961 tls->hsd->client_and_server_rand32, sizeof(tls->hsd->client_and_server_rand32)
1963 dump_hex("master secret:%s\n", tls->hsd->master_secret, sizeof(tls->hsd->master_secret));
1966 // 6.3. Key Calculation
1968 // The Record Protocol requires an algorithm to generate keys required
1969 // by the current connection state (see Appendix A.6) from the security
1970 // parameters provided by the handshake protocol.
1972 // The master secret is expanded into a sequence of secure bytes, which
1973 // is then split to a client write MAC key, a server write MAC key, a
1974 // client write encryption key, and a server write encryption key. Each
1975 // of these is generated from the byte sequence in that order. Unused
1976 // values are empty. Some AEAD ciphers may additionally require a
1977 // client write IV and a server write IV (see Section 6.2.3.3).
1979 // When keys and MAC keys are generated, the master secret is used as an
1982 // To generate the key material, compute
1984 // key_block = PRF(SecurityParameters.master_secret,
1986 // SecurityParameters.server_random +
1987 // SecurityParameters.client_random);
1989 // until enough output has been generated. Then, the key_block is
1990 // partitioned as follows:
1992 // client_write_MAC_key[SecurityParameters.mac_key_length]
1993 // server_write_MAC_key[SecurityParameters.mac_key_length]
1994 // client_write_key[SecurityParameters.enc_key_length]
1995 // server_write_key[SecurityParameters.enc_key_length]
1996 // client_write_IV[SecurityParameters.fixed_iv_length]
1997 // server_write_IV[SecurityParameters.fixed_iv_length]
2001 /* make "server_rand32 + client_rand32" */
2002 memcpy(&tmp64[0] , &tls->hsd->client_and_server_rand32[32], 32);
2003 memcpy(&tmp64[32], &tls->hsd->client_and_server_rand32[0] , 32);
2005 prf_hmac_sha256(/*tls,*/
2006 tls->client_write_MAC_key, 2 * (tls->MAC_size + tls->key_size + tls->IV_size),
2008 // server_write_MAC_key[]
2009 // client_write_key[]
2010 // server_write_key[]
2011 // client_write_IV[]
2012 // server_write_IV[]
2013 tls->hsd->master_secret, sizeof(tls->hsd->master_secret),
2017 tls->client_write_key = tls->client_write_MAC_key + (2 * tls->MAC_size);
2018 tls->server_write_key = tls->client_write_key + tls->key_size;
2019 tls->client_write_IV = tls->server_write_key + tls->key_size;
2020 tls->server_write_IV = tls->client_write_IV + tls->IV_size;
2021 dump_hex("client_write_MAC_key:%s\n",
2022 tls->client_write_MAC_key, tls->MAC_size
2024 dump_hex("client_write_key:%s\n",
2025 tls->client_write_key, tls->key_size
2027 dump_hex("client_write_IV:%s\n",
2028 tls->client_write_IV, tls->IV_size
2031 aes_setkey(&tls->aes_decrypt, tls->server_write_key, tls->key_size);
2032 aes_setkey(&tls->aes_encrypt, tls->client_write_key, tls->key_size);
2034 uint8_t iv[AES_BLOCK_SIZE];
2035 memset(iv, 0, AES_BLOCK_SIZE);
2036 aes_encrypt_one_block(&tls->aes_encrypt, iv, tls->H);
2041 static const uint8_t rec_CHANGE_CIPHER_SPEC[] = {
2042 RECORD_TYPE_CHANGE_CIPHER_SPEC, TLS_MAJ, TLS_MIN, 00, 01,
2046 static void send_change_cipher_spec(tls_state_t *tls)
2048 dbg(">> CHANGE_CIPHER_SPEC\n");
2049 xwrite(tls->ofd, rec_CHANGE_CIPHER_SPEC, sizeof(rec_CHANGE_CIPHER_SPEC));
2053 // A Finished message is always sent immediately after a change
2054 // cipher spec message to verify that the key exchange and
2055 // authentication processes were successful. It is essential that a
2056 // change cipher spec message be received between the other handshake
2057 // messages and the Finished message.
2059 // The Finished message is the first one protected with the just
2060 // negotiated algorithms, keys, and secrets. Recipients of Finished
2061 // messages MUST verify that the contents are correct. Once a side
2062 // has sent its Finished message and received and validated the
2063 // Finished message from its peer, it may begin to send and receive
2064 // application data over the connection.
2067 // opaque verify_data[verify_data_length];
2071 // PRF(master_secret, finished_label, Hash(handshake_messages))
2072 // [0..verify_data_length-1];
2075 // For Finished messages sent by the client, the string
2076 // "client finished". For Finished messages sent by the server,
2077 // the string "server finished".
2079 // Hash denotes a Hash of the handshake messages. For the PRF
2080 // defined in Section 5, the Hash MUST be the Hash used as the basis
2081 // for the PRF. Any cipher suite which defines a different PRF MUST
2082 // also define the Hash to use in the Finished computation.
2084 // In previous versions of TLS, the verify_data was always 12 octets
2085 // long. In the current version of TLS, it depends on the cipher
2086 // suite. Any cipher suite which does not explicitly specify
2087 // verify_data_length has a verify_data_length equal to 12. This
2088 // includes all existing cipher suites.
2089 static void send_client_finished(tls_state_t *tls)
2093 uint8_t len24_hi, len24_mid, len24_lo;
2094 uint8_t prf_result[12];
2096 struct finished *record = tls_get_outbuf(tls, sizeof(*record));
2097 uint8_t handshake_hash[TLS_MAX_MAC_SIZE];
2100 fill_handshake_record_hdr(record, HANDSHAKE_FINISHED, sizeof(*record));
2102 len = sha_end(&tls->hsd->handshake_hash_ctx, handshake_hash);
2104 prf_hmac_sha256(/*tls,*/
2105 record->prf_result, sizeof(record->prf_result),
2106 tls->hsd->master_secret, sizeof(tls->hsd->master_secret),
2110 dump_hex("from secret: %s\n", tls->hsd->master_secret, sizeof(tls->hsd->master_secret));
2111 dump_hex("from labelSeed: %s", "client finished", sizeof("client finished")-1);
2112 dump_hex("%s\n", handshake_hash, sizeof(handshake_hash));
2113 dump_hex("=> digest: %s\n", record->prf_result, sizeof(record->prf_result));
2115 dbg(">> FINISHED\n");
2116 xwrite_encrypted(tls, sizeof(*record), RECORD_TYPE_HANDSHAKE);
2119 void FAST_FUNC tls_handshake(tls_state_t *tls, const char *sni)
2121 // Client RFC 5246 Server
2122 // (*) - optional messages, not always sent
2124 // ClientHello ------->
2127 // ServerKeyExchange*
2128 // CertificateRequest*
2129 // <------- ServerHelloDone
2131 // ClientKeyExchange
2132 // CertificateVerify*
2133 // [ChangeCipherSpec]
2134 // Finished ------->
2135 // [ChangeCipherSpec]
2136 // <------- Finished
2137 // Application Data <------> Application Data
2141 send_client_hello_and_alloc_hsd(tls, sni);
2142 get_server_hello(tls);
2145 // The server MUST send a Certificate message whenever the agreed-
2146 // upon key exchange method uses certificates for authentication
2147 // (this includes all key exchange methods defined in this document
2148 // except DH_anon). This message will always immediately follow the
2149 // ServerHello message.
2151 // IOW: in practice, Certificate *always* follows.
2152 // (for example, kernel.org does not even accept DH_anon cipher id)
2153 get_server_cert(tls);
2155 len = tls_xread_handshake_block(tls, 4);
2156 if (tls->inbuf[RECHDR_LEN] == HANDSHAKE_SERVER_KEY_EXCHANGE) {
2158 // 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...
2160 // with TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA: 461 bytes:
2161 // 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...
2163 // RFC 8422 5.4. Server Key Exchange
2164 // This message is sent when using the ECDHE_ECDSA, ECDHE_RSA, and
2165 // ECDH_anon key exchange algorithms.
2166 // This message is used to convey the server's ephemeral ECDH public key
2167 // (and the corresponding elliptic curve domain parameters) to the
2169 dbg("<< SERVER_KEY_EXCHANGE len:%u\n", len);
2170 dump_raw_in("<< %s\n", tls->inbuf, RECHDR_LEN + len);
2171 if (tls->flags & NEED_EC_KEY)
2172 process_server_key(tls, len);
2174 // read next handshake block
2175 len = tls_xread_handshake_block(tls, 4);
2178 got_cert_req = (tls->inbuf[RECHDR_LEN] == HANDSHAKE_CERTIFICATE_REQUEST);
2180 dbg("<< CERTIFICATE_REQUEST\n");
2181 // RFC 5246: "If no suitable certificate is available,
2182 // the client MUST send a certificate message containing no
2183 // certificates. That is, the certificate_list structure has a
2184 // length of zero. ...
2185 // Client certificates are sent using the Certificate structure
2186 // defined in Section 7.4.2."
2187 // (i.e. the same format as server certs)
2189 /*send_empty_client_cert(tls); - WRONG (breaks handshake hash calc) */
2190 /* need to hash _all_ server replies first, up to ServerHelloDone */
2191 len = tls_xread_handshake_block(tls, 4);
2194 if (tls->inbuf[RECHDR_LEN] != HANDSHAKE_SERVER_HELLO_DONE) {
2195 bad_record_die(tls, "'server hello done'", len);
2197 // 0e 000000 (len:0)
2198 dbg("<< SERVER_HELLO_DONE\n");
2201 send_empty_client_cert(tls);
2203 send_client_key_exchange(tls);
2205 send_change_cipher_spec(tls);
2206 /* from now on we should send encrypted */
2207 /* tls->write_seq64_be = 0; - already is */
2208 tls->flags |= ENCRYPT_ON_WRITE;
2210 send_client_finished(tls);
2212 /* Get CHANGE_CIPHER_SPEC */
2213 len = tls_xread_record(tls, "switch to encrypted traffic");
2214 if (len != 1 || memcmp(tls->inbuf, rec_CHANGE_CIPHER_SPEC, 6) != 0)
2215 bad_record_die(tls, "switch to encrypted traffic", len);
2216 dbg("<< CHANGE_CIPHER_SPEC\n");
2218 if (ALLOW_RSA_NULL_SHA256
2219 && tls->cipher_id == TLS_RSA_WITH_NULL_SHA256
2221 tls->min_encrypted_len_on_read = tls->MAC_size;
2223 if (!(tls->flags & ENCRYPTION_AESGCM)) {
2224 unsigned mac_blocks = (unsigned)(tls->MAC_size + AES_BLOCK_SIZE-1) / AES_BLOCK_SIZE;
2225 /* all incoming packets now should be encrypted and have
2226 * at least IV + (MAC padded to blocksize):
2228 tls->min_encrypted_len_on_read = AES_BLOCK_SIZE + (mac_blocks * AES_BLOCK_SIZE);
2230 tls->min_encrypted_len_on_read = 8 + AES_BLOCK_SIZE;
2232 dbg("min_encrypted_len_on_read: %u\n", tls->min_encrypted_len_on_read);
2234 /* Get (encrypted) FINISHED from the server */
2235 len = tls_xread_record(tls, "'server finished'");
2236 if (len < 4 || tls->inbuf[RECHDR_LEN] != HANDSHAKE_FINISHED)
2237 bad_record_die(tls, "'server finished'", len);
2238 dbg("<< FINISHED\n");
2239 /* application data can be sent/received */
2241 /* free handshake data */
2242 psRsaKey_clear(&tls->hsd->server_rsa_pub_key);
2244 // memset(tls->hsd, 0, tls->hsd->hsd_size);
2249 static void tls_xwrite(tls_state_t *tls, int len)
2252 xwrite_encrypted(tls, len, RECORD_TYPE_APPLICATION_DATA);
2255 // To run a test server using openssl:
2256 // openssl req -x509 -newkey rsa:$((4096/4*3)) -keyout key.pem -out server.pem -nodes -days 99999 -subj '/CN=localhost'
2257 // openssl s_server -key key.pem -cert server.pem -debug -tls1_2
2259 // Unencryped SHA256 example:
2260 // openssl req -x509 -newkey rsa:$((4096/4*3)) -keyout key.pem -out server.pem -nodes -days 99999 -subj '/CN=localhost'
2261 // openssl s_server -key key.pem -cert server.pem -debug -tls1_2 -cipher NULL
2262 // openssl s_client -connect 127.0.0.1:4433 -debug -tls1_2 -cipher NULL-SHA256
2264 void FAST_FUNC tls_run_copy_loop(tls_state_t *tls, unsigned flags)
2267 const int INBUF_STEP = 4 * 1024;
2268 struct pollfd pfds[2];
2270 pfds[0].fd = STDIN_FILENO;
2271 pfds[0].events = POLLIN;
2272 pfds[1].fd = tls->ifd;
2273 pfds[1].events = POLLIN;
2275 inbuf_size = INBUF_STEP;
2279 if (safe_poll(pfds, 2, -1) < 0)
2280 bb_perror_msg_and_die("poll");
2282 if (pfds[0].revents) {
2285 dbg("STDIN HAS DATA\n");
2286 buf = tls_get_outbuf(tls, inbuf_size);
2287 nread = safe_read(STDIN_FILENO, buf, inbuf_size);
2289 /* We'd want to do this: */
2290 /* Close outgoing half-connection so they get EOF,
2291 * but leave incoming alone so we can see response
2293 //shutdown(tls->ofd, SHUT_WR);
2294 /* But TLS has no way to encode this,
2295 * doubt it's ok to do it "raw"
2298 tls_free_outbuf(tls); /* mem usage optimization */
2299 if (flags & TLSLOOP_EXIT_ON_LOCAL_EOF)
2302 if (nread == inbuf_size) {
2303 /* TLS has per record overhead, if input comes fast,
2304 * read, encrypt and send bigger chunks
2306 inbuf_size += INBUF_STEP;
2307 if (inbuf_size > TLS_MAX_OUTBUF)
2308 inbuf_size = TLS_MAX_OUTBUF;
2310 tls_xwrite(tls, nread);
2313 if (pfds[1].revents) {
2314 dbg("NETWORK HAS DATA\n");
2316 nread = tls_xread_record(tls, "encrypted data");
2318 /* TLS protocol has no real concept of one-sided shutdowns:
2319 * if we get "TLS EOF" from the peer, writes will fail too
2322 //close(STDOUT_FILENO);
2323 //tls_free_inbuf(tls); /* mem usage optimization */
2327 if (tls->inbuf[0] != RECORD_TYPE_APPLICATION_DATA)
2328 bad_record_die(tls, "encrypted data", nread);
2329 xwrite(STDOUT_FILENO, tls->inbuf + RECHDR_LEN, nread);
2330 /* We may already have a complete next record buffered,
2331 * can process it without network reads (and possible blocking)
2333 if (tls_has_buffered_record(tls))