xref: /openssl/ssl/tls13_enc.c (revision 7ed6de99)
1 /*
2  * Copyright 2016-2024 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include <stdlib.h>
11 #include "ssl_local.h"
12 #include "internal/ktls.h"
13 #include "record/record_local.h"
14 #include "internal/cryptlib.h"
15 #include <openssl/evp.h>
16 #include <openssl/kdf.h>
17 #include <openssl/core_names.h>
18 
19 #define TLS13_MAX_LABEL_LEN     249
20 
21 /* ASCII: "tls13 ", in hex for EBCDIC compatibility */
22 static const unsigned char label_prefix[] = "\x74\x6C\x73\x31\x33\x20";
23 
24 /*
25  * Given a |secret|; a |label| of length |labellen|; and |data| of length
26  * |datalen| (e.g. typically a hash of the handshake messages), derive a new
27  * secret |outlen| bytes long and store it in the location pointed to be |out|.
28  * The |data| value may be zero length. Any errors will be treated as fatal if
29  * |fatal| is set. Returns 1 on success  0 on failure.
30  * If |raise_error| is set, ERR_raise is called on failure.
31  */
tls13_hkdf_expand_ex(OSSL_LIB_CTX * libctx,const char * propq,const EVP_MD * md,const unsigned char * secret,const unsigned char * label,size_t labellen,const unsigned char * data,size_t datalen,unsigned char * out,size_t outlen,int raise_error)32 int tls13_hkdf_expand_ex(OSSL_LIB_CTX *libctx, const char *propq,
33                          const EVP_MD *md,
34                          const unsigned char *secret,
35                          const unsigned char *label, size_t labellen,
36                          const unsigned char *data, size_t datalen,
37                          unsigned char *out, size_t outlen, int raise_error)
38 {
39     EVP_KDF *kdf = EVP_KDF_fetch(libctx, OSSL_KDF_NAME_TLS1_3_KDF, propq);
40     EVP_KDF_CTX *kctx;
41     OSSL_PARAM params[7], *p = params;
42     int mode = EVP_PKEY_HKDEF_MODE_EXPAND_ONLY;
43     const char *mdname = EVP_MD_get0_name(md);
44     int ret;
45     size_t hashlen;
46 
47     kctx = EVP_KDF_CTX_new(kdf);
48     EVP_KDF_free(kdf);
49     if (kctx == NULL)
50         return 0;
51 
52     if (labellen > TLS13_MAX_LABEL_LEN) {
53         if (raise_error)
54             /*
55              * Probably we have been called from SSL_export_keying_material(),
56              * or SSL_export_keying_material_early().
57              */
58             ERR_raise(ERR_LIB_SSL, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
59 
60         EVP_KDF_CTX_free(kctx);
61         return 0;
62     }
63 
64     if ((ret = EVP_MD_get_size(md)) <= 0) {
65         EVP_KDF_CTX_free(kctx);
66         if (raise_error)
67             ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
68         return 0;
69     }
70     hashlen = (size_t)ret;
71 
72     *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
73     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
74                                             (char *)mdname, 0);
75     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
76                                              (unsigned char *)secret, hashlen);
77     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PREFIX,
78                                              (unsigned char *)label_prefix,
79                                              sizeof(label_prefix) - 1);
80     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_LABEL,
81                                              (unsigned char *)label, labellen);
82     if (data != NULL)
83         *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_DATA,
84                                                  (unsigned char *)data,
85                                                  datalen);
86     *p++ = OSSL_PARAM_construct_end();
87 
88     ret = EVP_KDF_derive(kctx, out, outlen, params) <= 0;
89     EVP_KDF_CTX_free(kctx);
90 
91     if (ret != 0) {
92         if (raise_error)
93             ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
94     }
95 
96     return ret == 0;
97 }
98 
tls13_hkdf_expand(SSL_CONNECTION * s,const EVP_MD * md,const unsigned char * secret,const unsigned char * label,size_t labellen,const unsigned char * data,size_t datalen,unsigned char * out,size_t outlen,int fatal)99 int tls13_hkdf_expand(SSL_CONNECTION *s, const EVP_MD *md,
100                       const unsigned char *secret,
101                       const unsigned char *label, size_t labellen,
102                       const unsigned char *data, size_t datalen,
103                       unsigned char *out, size_t outlen, int fatal)
104 {
105     int ret;
106     SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
107 
108     ret = tls13_hkdf_expand_ex(sctx->libctx, sctx->propq, md,
109                                secret, label, labellen, data, datalen,
110                                out, outlen, !fatal);
111     if (ret == 0 && fatal)
112         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
113 
114     return ret;
115 }
116 
117 /*
118  * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
119  * success  0 on failure.
120  */
tls13_derive_key(SSL_CONNECTION * s,const EVP_MD * md,const unsigned char * secret,unsigned char * key,size_t keylen)121 int tls13_derive_key(SSL_CONNECTION *s, const EVP_MD *md,
122                      const unsigned char *secret,
123                      unsigned char *key, size_t keylen)
124 {
125     /* ASCII: "key", in hex for EBCDIC compatibility */
126     static const unsigned char keylabel[] = "\x6B\x65\x79";
127 
128     return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
129                              NULL, 0, key, keylen, 1);
130 }
131 
132 /*
133  * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
134  * success  0 on failure.
135  */
tls13_derive_iv(SSL_CONNECTION * s,const EVP_MD * md,const unsigned char * secret,unsigned char * iv,size_t ivlen)136 int tls13_derive_iv(SSL_CONNECTION *s, const EVP_MD *md,
137                     const unsigned char *secret,
138                     unsigned char *iv, size_t ivlen)
139 {
140     /* ASCII: "iv", in hex for EBCDIC compatibility */
141     static const unsigned char ivlabel[] = "\x69\x76";
142 
143     return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
144                              NULL, 0, iv, ivlen, 1);
145 }
146 
tls13_derive_finishedkey(SSL_CONNECTION * s,const EVP_MD * md,const unsigned char * secret,unsigned char * fin,size_t finlen)147 int tls13_derive_finishedkey(SSL_CONNECTION *s, const EVP_MD *md,
148                              const unsigned char *secret,
149                              unsigned char *fin, size_t finlen)
150 {
151     /* ASCII: "finished", in hex for EBCDIC compatibility */
152     static const unsigned char finishedlabel[] = "\x66\x69\x6E\x69\x73\x68\x65\x64";
153 
154     return tls13_hkdf_expand(s, md, secret, finishedlabel,
155                              sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1);
156 }
157 
158 /*
159  * Given the previous secret |prevsecret| and a new input secret |insecret| of
160  * length |insecretlen|, generate a new secret and store it in the location
161  * pointed to by |outsecret|. Returns 1 on success  0 on failure.
162  */
tls13_generate_secret(SSL_CONNECTION * s,const EVP_MD * md,const unsigned char * prevsecret,const unsigned char * insecret,size_t insecretlen,unsigned char * outsecret)163 int tls13_generate_secret(SSL_CONNECTION *s, const EVP_MD *md,
164                           const unsigned char *prevsecret,
165                           const unsigned char *insecret,
166                           size_t insecretlen,
167                           unsigned char *outsecret)
168 {
169     size_t mdlen;
170     int mdleni;
171     int ret;
172     EVP_KDF *kdf;
173     EVP_KDF_CTX *kctx;
174     OSSL_PARAM params[7], *p = params;
175     int mode = EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY;
176     const char *mdname = EVP_MD_get0_name(md);
177     /* ASCII: "derived", in hex for EBCDIC compatibility */
178     static const char derived_secret_label[] = "\x64\x65\x72\x69\x76\x65\x64";
179     SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
180 
181     kdf = EVP_KDF_fetch(sctx->libctx, OSSL_KDF_NAME_TLS1_3_KDF, sctx->propq);
182     kctx = EVP_KDF_CTX_new(kdf);
183     EVP_KDF_free(kdf);
184     if (kctx == NULL) {
185         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
186         return 0;
187     }
188 
189     mdleni = EVP_MD_get_size(md);
190     /* Ensure cast to size_t is safe */
191     if (!ossl_assert(mdleni > 0)) {
192         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
193         EVP_KDF_CTX_free(kctx);
194         return 0;
195     }
196     mdlen = (size_t)mdleni;
197 
198     *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
199     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
200                                             (char *)mdname, 0);
201     if (insecret != NULL)
202         *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
203                                                  (unsigned char *)insecret,
204                                                  insecretlen);
205     if (prevsecret != NULL)
206         *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT,
207                                                  (unsigned char *)prevsecret, mdlen);
208     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PREFIX,
209                                              (unsigned char *)label_prefix,
210                                              sizeof(label_prefix) - 1);
211     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_LABEL,
212                                              (unsigned char *)derived_secret_label,
213                                              sizeof(derived_secret_label) - 1);
214     *p++ = OSSL_PARAM_construct_end();
215 
216     ret = EVP_KDF_derive(kctx, outsecret, mdlen, params) <= 0;
217 
218     if (ret != 0)
219         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
220 
221     EVP_KDF_CTX_free(kctx);
222     return ret == 0;
223 }
224 
225 /*
226  * Given an input secret |insecret| of length |insecretlen| generate the
227  * handshake secret. This requires the early secret to already have been
228  * generated. Returns 1 on success  0 on failure.
229  */
tls13_generate_handshake_secret(SSL_CONNECTION * s,const unsigned char * insecret,size_t insecretlen)230 int tls13_generate_handshake_secret(SSL_CONNECTION *s,
231                                     const unsigned char *insecret,
232                                     size_t insecretlen)
233 {
234     /* Calls SSLfatal() if required */
235     return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
236                                  insecret, insecretlen,
237                                  (unsigned char *)&s->handshake_secret);
238 }
239 
240 /*
241  * Given the handshake secret |prev| of length |prevlen| generate the master
242  * secret and store its length in |*secret_size|. Returns 1 on success  0 on
243  * failure.
244  */
tls13_generate_master_secret(SSL_CONNECTION * s,unsigned char * out,unsigned char * prev,size_t prevlen,size_t * secret_size)245 int tls13_generate_master_secret(SSL_CONNECTION *s, unsigned char *out,
246                                  unsigned char *prev, size_t prevlen,
247                                  size_t *secret_size)
248 {
249     const EVP_MD *md = ssl_handshake_md(s);
250     int md_size;
251 
252     md_size = EVP_MD_get_size(md);
253     if (md_size <= 0) {
254         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
255         return 0;
256     }
257     *secret_size = (size_t)md_size;
258     /* Calls SSLfatal() if required */
259     return tls13_generate_secret(s, md, prev, NULL, 0, out);
260 }
261 
262 /*
263  * Generates the mac for the Finished message. Returns the length of the MAC or
264  * 0 on error.
265  */
tls13_final_finish_mac(SSL_CONNECTION * s,const char * str,size_t slen,unsigned char * out)266 size_t tls13_final_finish_mac(SSL_CONNECTION *s, const char *str, size_t slen,
267                              unsigned char *out)
268 {
269     const EVP_MD *md = ssl_handshake_md(s);
270     const char *mdname = EVP_MD_get0_name(md);
271     unsigned char hash[EVP_MAX_MD_SIZE];
272     unsigned char finsecret[EVP_MAX_MD_SIZE];
273     unsigned char *key = NULL;
274     size_t len = 0, hashlen;
275     OSSL_PARAM params[2], *p = params;
276     SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
277 
278     if (md == NULL)
279         return 0;
280 
281     /* Safe to cast away const here since we're not "getting" any data */
282     if (sctx->propq != NULL)
283         *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_PROPERTIES,
284                                                 (char *)sctx->propq,
285                                                 0);
286     *p = OSSL_PARAM_construct_end();
287 
288     if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
289         /* SSLfatal() already called */
290         goto err;
291     }
292 
293     if (str == SSL_CONNECTION_GET_SSL(s)->method->ssl3_enc->server_finished_label) {
294         key = s->server_finished_secret;
295     } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
296         key = s->client_finished_secret;
297     } else {
298         if (!tls13_derive_finishedkey(s, md,
299                                       s->client_app_traffic_secret,
300                                       finsecret, hashlen))
301             goto err;
302         key = finsecret;
303     }
304 
305     if (!EVP_Q_mac(sctx->libctx, "HMAC", sctx->propq, mdname,
306                    params, key, hashlen, hash, hashlen,
307                    /* outsize as per sizeof(peer_finish_md) */
308                    out, EVP_MAX_MD_SIZE * 2, &len)) {
309         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
310         goto err;
311     }
312 
313  err:
314     OPENSSL_cleanse(finsecret, sizeof(finsecret));
315     return len;
316 }
317 
318 /*
319  * There isn't really a key block in TLSv1.3, but we still need this function
320  * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
321  */
tls13_setup_key_block(SSL_CONNECTION * s)322 int tls13_setup_key_block(SSL_CONNECTION *s)
323 {
324     const EVP_CIPHER *c;
325     const EVP_MD *hash;
326     int mac_type = NID_undef;
327     size_t mac_secret_size = 0;
328 
329     s->session->cipher = s->s3.tmp.new_cipher;
330     if (!ssl_cipher_get_evp(SSL_CONNECTION_GET_CTX(s), s->session, &c, &hash,
331                             &mac_type, &mac_secret_size, NULL, 0)) {
332         /* Error is already recorded */
333         SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
334         return 0;
335     }
336 
337     ssl_evp_cipher_free(s->s3.tmp.new_sym_enc);
338     s->s3.tmp.new_sym_enc = c;
339     ssl_evp_md_free(s->s3.tmp.new_hash);
340     s->s3.tmp.new_hash = hash;
341     s->s3.tmp.new_mac_pkey_type = mac_type;
342     s->s3.tmp.new_mac_secret_size = mac_secret_size;
343 
344     return 1;
345 }
346 
derive_secret_key_and_iv(SSL_CONNECTION * s,const EVP_MD * md,const EVP_CIPHER * ciph,int mac_type,const EVP_MD * mac_md,const unsigned char * insecret,const unsigned char * hash,const unsigned char * label,size_t labellen,unsigned char * secret,unsigned char * key,size_t * keylen,unsigned char ** iv,size_t * ivlen,size_t * taglen)347 static int derive_secret_key_and_iv(SSL_CONNECTION *s, const EVP_MD *md,
348                                     const EVP_CIPHER *ciph,
349                                     int mac_type,
350                                     const EVP_MD *mac_md,
351                                     const unsigned char *insecret,
352                                     const unsigned char *hash,
353                                     const unsigned char *label,
354                                     size_t labellen, unsigned char *secret,
355                                     unsigned char *key, size_t *keylen,
356                                     unsigned char **iv, size_t *ivlen,
357                                     size_t *taglen)
358 {
359     int hashleni = EVP_MD_get_size(md);
360     size_t hashlen;
361     int mode, mac_mdleni;
362 
363     /* Ensure cast to size_t is safe */
364     if (!ossl_assert(hashleni > 0)) {
365         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
366         return 0;
367     }
368     hashlen = (size_t)hashleni;
369 
370     if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
371                            secret, hashlen, 1)) {
372         /* SSLfatal() already called */
373         return 0;
374     }
375 
376     /* if ciph is NULL cipher, then use new_hash to calculate keylen */
377     if (EVP_CIPHER_is_a(ciph, "NULL")
378         && mac_md != NULL
379         && mac_type == NID_hmac) {
380         mac_mdleni = EVP_MD_get_size(mac_md);
381 
382         if (mac_mdleni <= 0) {
383             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
384             return 0;
385         }
386         *ivlen = *taglen = (size_t)mac_mdleni;
387         *keylen = s->s3.tmp.new_mac_secret_size;
388     } else {
389 
390         *keylen = EVP_CIPHER_get_key_length(ciph);
391 
392         mode = EVP_CIPHER_get_mode(ciph);
393         if (mode == EVP_CIPH_CCM_MODE) {
394             uint32_t algenc;
395 
396             *ivlen = EVP_CCM_TLS_IV_LEN;
397             if (s->s3.tmp.new_cipher != NULL) {
398                 algenc = s->s3.tmp.new_cipher->algorithm_enc;
399             } else if (s->session->cipher != NULL) {
400                 /* We've not selected a cipher yet - we must be doing early data */
401                 algenc = s->session->cipher->algorithm_enc;
402             } else if (s->psksession != NULL && s->psksession->cipher != NULL) {
403                 /* We must be doing early data with out-of-band PSK */
404                 algenc = s->psksession->cipher->algorithm_enc;
405             } else {
406                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
407                 return 0;
408             }
409             if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
410                 *taglen = EVP_CCM8_TLS_TAG_LEN;
411             else
412                 *taglen = EVP_CCM_TLS_TAG_LEN;
413         } else {
414             int iivlen;
415 
416             if (mode == EVP_CIPH_GCM_MODE) {
417                 *taglen = EVP_GCM_TLS_TAG_LEN;
418             } else {
419                 /* CHACHA20P-POLY1305 */
420                 *taglen = EVP_CHACHAPOLY_TLS_TAG_LEN;
421             }
422             iivlen = EVP_CIPHER_get_iv_length(ciph);
423             if (iivlen < 0) {
424                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
425                 return 0;
426             }
427             *ivlen = iivlen;
428         }
429     }
430 
431     if (*ivlen > EVP_MAX_IV_LENGTH) {
432         *iv = OPENSSL_malloc(*ivlen);
433         if (*iv == NULL) {
434             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
435             return 0;
436         }
437     }
438 
439     if (!tls13_derive_key(s, md, secret, key, *keylen)
440             || !tls13_derive_iv(s, md, secret, *iv, *ivlen)) {
441         /* SSLfatal() already called */
442         return 0;
443     }
444 
445     return 1;
446 }
447 
tls13_change_cipher_state(SSL_CONNECTION * s,int which)448 int tls13_change_cipher_state(SSL_CONNECTION *s, int which)
449 {
450     /* ASCII: "c e traffic", in hex for EBCDIC compatibility */
451     static const unsigned char client_early_traffic[] = "\x63\x20\x65\x20\x74\x72\x61\x66\x66\x69\x63";
452     /* ASCII: "c hs traffic", in hex for EBCDIC compatibility */
453     static const unsigned char client_handshake_traffic[] = "\x63\x20\x68\x73\x20\x74\x72\x61\x66\x66\x69\x63";
454     /* ASCII: "c ap traffic", in hex for EBCDIC compatibility */
455     static const unsigned char client_application_traffic[] = "\x63\x20\x61\x70\x20\x74\x72\x61\x66\x66\x69\x63";
456     /* ASCII: "s hs traffic", in hex for EBCDIC compatibility */
457     static const unsigned char server_handshake_traffic[] = "\x73\x20\x68\x73\x20\x74\x72\x61\x66\x66\x69\x63";
458     /* ASCII: "s ap traffic", in hex for EBCDIC compatibility */
459     static const unsigned char server_application_traffic[] = "\x73\x20\x61\x70\x20\x74\x72\x61\x66\x66\x69\x63";
460     /* ASCII: "exp master", in hex for EBCDIC compatibility */
461     static const unsigned char exporter_master_secret[] = "\x65\x78\x70\x20\x6D\x61\x73\x74\x65\x72";
462     /* ASCII: "res master", in hex for EBCDIC compatibility */
463     static const unsigned char resumption_master_secret[] = "\x72\x65\x73\x20\x6D\x61\x73\x74\x65\x72";
464     /* ASCII: "e exp master", in hex for EBCDIC compatibility */
465     static const unsigned char early_exporter_master_secret[] = "\x65\x20\x65\x78\x70\x20\x6D\x61\x73\x74\x65\x72";
466     unsigned char iv_intern[EVP_MAX_IV_LENGTH];
467     unsigned char *iv = iv_intern;
468     unsigned char key[EVP_MAX_KEY_LENGTH];
469     unsigned char secret[EVP_MAX_MD_SIZE];
470     unsigned char hashval[EVP_MAX_MD_SIZE];
471     unsigned char *hash = hashval;
472     unsigned char *insecret;
473     unsigned char *finsecret = NULL;
474     const char *log_label = NULL;
475     int finsecretlen = 0;
476     const unsigned char *label;
477     size_t labellen, hashlen = 0;
478     int ret = 0;
479     const EVP_MD *md = NULL, *mac_md = NULL;
480     const EVP_CIPHER *cipher = NULL;
481     int mac_pkey_type = NID_undef;
482     SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
483     size_t keylen, ivlen = EVP_MAX_IV_LENGTH, taglen;
484     int level;
485     int direction = (which & SSL3_CC_READ) != 0 ? OSSL_RECORD_DIRECTION_READ
486                                                 : OSSL_RECORD_DIRECTION_WRITE;
487 
488     if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
489             || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
490         if ((which & SSL3_CC_EARLY) != 0) {
491             EVP_MD_CTX *mdctx = NULL;
492             long handlen;
493             void *hdata;
494             unsigned int hashlenui;
495             const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
496 
497             insecret = s->early_secret;
498             label = client_early_traffic;
499             labellen = sizeof(client_early_traffic) - 1;
500             log_label = CLIENT_EARLY_LABEL;
501 
502             handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
503             if (handlen <= 0) {
504                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_HANDSHAKE_LENGTH);
505                 goto err;
506             }
507 
508             if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
509                     && s->max_early_data > 0
510                     && s->session->ext.max_early_data == 0) {
511                 /*
512                  * If we are attempting to send early data, and we've decided to
513                  * actually do it but max_early_data in s->session is 0 then we
514                  * must be using an external PSK.
515                  */
516                 if (!ossl_assert(s->psksession != NULL
517                         && s->max_early_data ==
518                            s->psksession->ext.max_early_data)) {
519                     SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
520                     goto err;
521                 }
522                 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
523             }
524             if (sslcipher == NULL) {
525                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_PSK);
526                 goto err;
527             }
528 
529             /*
530              * This ups the ref count on cipher so we better make sure we free
531              * it again
532              */
533             if (!ssl_cipher_get_evp_cipher(sctx, sslcipher, &cipher)) {
534                 /* Error is already recorded */
535                 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
536                 goto err;
537             }
538 
539             if (((EVP_CIPHER_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) == 0)
540                 && (!ssl_cipher_get_evp_md_mac(sctx, sslcipher, &mac_md,
541                                                &mac_pkey_type, NULL))) {
542                 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
543                 goto err;
544             }
545 
546             /*
547              * We need to calculate the handshake digest using the digest from
548              * the session. We haven't yet selected our ciphersuite so we can't
549              * use ssl_handshake_md().
550              */
551             mdctx = EVP_MD_CTX_new();
552             if (mdctx == NULL) {
553                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
554                 goto err;
555             }
556 
557             md = ssl_md(sctx, sslcipher->algorithm2);
558             if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
559                     || !EVP_DigestUpdate(mdctx, hdata, handlen)
560                     || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
561                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
562                 EVP_MD_CTX_free(mdctx);
563                 goto err;
564             }
565             hashlen = hashlenui;
566             EVP_MD_CTX_free(mdctx);
567 
568             if (!tls13_hkdf_expand(s, md, insecret,
569                                    early_exporter_master_secret,
570                                    sizeof(early_exporter_master_secret) - 1,
571                                    hashval, hashlen,
572                                    s->early_exporter_master_secret, hashlen,
573                                    1)) {
574                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
575                 goto err;
576             }
577 
578             if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
579                                 s->early_exporter_master_secret, hashlen)) {
580                 /* SSLfatal() already called */
581                 goto err;
582             }
583         } else if (which & SSL3_CC_HANDSHAKE) {
584             insecret = s->handshake_secret;
585             finsecret = s->client_finished_secret;
586             finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
587             if (finsecretlen <= 0) {
588                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
589                 goto err;
590             }
591             label = client_handshake_traffic;
592             labellen = sizeof(client_handshake_traffic) - 1;
593             log_label = CLIENT_HANDSHAKE_LABEL;
594             /*
595              * The handshake hash used for the server read/client write handshake
596              * traffic secret is the same as the hash for the server
597              * write/client read handshake traffic secret. However, if we
598              * processed early data then we delay changing the server
599              * read/client write cipher state until later, and the handshake
600              * hashes have moved on. Therefore we use the value saved earlier
601              * when we did the server write/client read change cipher state.
602              */
603             hash = s->handshake_traffic_hash;
604         } else {
605             insecret = s->master_secret;
606             label = client_application_traffic;
607             labellen = sizeof(client_application_traffic) - 1;
608             log_label = CLIENT_APPLICATION_LABEL;
609             /*
610              * For this we only use the handshake hashes up until the server
611              * Finished hash. We do not include the client's Finished, which is
612              * what ssl_handshake_hash() would give us. Instead we use the
613              * previously saved value.
614              */
615             hash = s->server_finished_hash;
616         }
617     } else {
618         /* Early data never applies to client-read/server-write */
619         if (which & SSL3_CC_HANDSHAKE) {
620             insecret = s->handshake_secret;
621             finsecret = s->server_finished_secret;
622             finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
623             if (finsecretlen <= 0) {
624                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
625                 goto err;
626             }
627             label = server_handshake_traffic;
628             labellen = sizeof(server_handshake_traffic) - 1;
629             log_label = SERVER_HANDSHAKE_LABEL;
630         } else {
631             insecret = s->master_secret;
632             label = server_application_traffic;
633             labellen = sizeof(server_application_traffic) - 1;
634             log_label = SERVER_APPLICATION_LABEL;
635         }
636     }
637 
638     if ((which & SSL3_CC_EARLY) == 0) {
639         md = ssl_handshake_md(s);
640         cipher = s->s3.tmp.new_sym_enc;
641         mac_md = s->s3.tmp.new_hash;
642         mac_pkey_type = s->s3.tmp.new_mac_pkey_type;
643         if (!ssl3_digest_cached_records(s, 1)
644                 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
645             /* SSLfatal() already called */;
646             goto err;
647         }
648     }
649 
650     /*
651      * Save the hash of handshakes up to now for use when we calculate the
652      * client application traffic secret
653      */
654     if (label == server_application_traffic)
655         memcpy(s->server_finished_hash, hashval, hashlen);
656 
657     if (label == server_handshake_traffic)
658         memcpy(s->handshake_traffic_hash, hashval, hashlen);
659 
660     if (label == client_application_traffic) {
661         /*
662          * We also create the resumption master secret, but this time use the
663          * hash for the whole handshake including the Client Finished
664          */
665         if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
666                                resumption_master_secret,
667                                sizeof(resumption_master_secret) - 1,
668                                hashval, hashlen, s->resumption_master_secret,
669                                hashlen, 1)) {
670             /* SSLfatal() already called */
671             goto err;
672         }
673     }
674 
675     /* check whether cipher is known */
676     if (!ossl_assert(cipher != NULL))
677         goto err;
678 
679     if (!derive_secret_key_and_iv(s, md, cipher, mac_pkey_type, mac_md,
680                                   insecret, hash, label, labellen, secret, key,
681                                   &keylen, &iv, &ivlen, &taglen)) {
682         /* SSLfatal() already called */
683         goto err;
684     }
685 
686     if (label == server_application_traffic) {
687         memcpy(s->server_app_traffic_secret, secret, hashlen);
688         /* Now we create the exporter master secret */
689         if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
690                                exporter_master_secret,
691                                sizeof(exporter_master_secret) - 1,
692                                hash, hashlen, s->exporter_master_secret,
693                                hashlen, 1)) {
694             /* SSLfatal() already called */
695             goto err;
696         }
697 
698         if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
699                             hashlen)) {
700             /* SSLfatal() already called */
701             goto err;
702         }
703     } else if (label == client_application_traffic)
704         memcpy(s->client_app_traffic_secret, secret, hashlen);
705 
706     if (!ssl_log_secret(s, log_label, secret, hashlen)) {
707         /* SSLfatal() already called */
708         goto err;
709     }
710 
711     if (finsecret != NULL
712             && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
713                                          finsecret, (size_t)finsecretlen)) {
714         /* SSLfatal() already called */
715         goto err;
716     }
717 
718     if ((which & SSL3_CC_WRITE) != 0) {
719         if (!s->server && label == client_early_traffic)
720             s->rlayer.wrlmethod->set_plain_alerts(s->rlayer.wrl, 1);
721         else
722             s->rlayer.wrlmethod->set_plain_alerts(s->rlayer.wrl, 0);
723     }
724 
725     level = (which & SSL3_CC_EARLY) != 0
726             ? OSSL_RECORD_PROTECTION_LEVEL_EARLY
727             : ((which &SSL3_CC_HANDSHAKE) != 0
728                ? OSSL_RECORD_PROTECTION_LEVEL_HANDSHAKE
729                : OSSL_RECORD_PROTECTION_LEVEL_APPLICATION);
730 
731     if (!ssl_set_new_record_layer(s, s->version,
732                                   direction,
733                                   level, secret, hashlen, key, keylen, iv,
734                                   ivlen, NULL, 0, cipher, taglen,
735                                   mac_pkey_type, mac_md, NULL, md)) {
736         /* SSLfatal already called */
737         goto err;
738     }
739 
740     ret = 1;
741  err:
742     if ((which & SSL3_CC_EARLY) != 0) {
743         /* We up-refed this so now we need to down ref */
744         if ((EVP_CIPHER_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) == 0)
745             ssl_evp_md_free(mac_md);
746         ssl_evp_cipher_free(cipher);
747     }
748     OPENSSL_cleanse(key, sizeof(key));
749     OPENSSL_cleanse(secret, sizeof(secret));
750     if (iv != iv_intern)
751         OPENSSL_free(iv);
752     return ret;
753 }
754 
tls13_update_key(SSL_CONNECTION * s,int sending)755 int tls13_update_key(SSL_CONNECTION *s, int sending)
756 {
757     /* ASCII: "traffic upd", in hex for EBCDIC compatibility */
758     static const unsigned char application_traffic[] = "\x74\x72\x61\x66\x66\x69\x63\x20\x75\x70\x64";
759     const EVP_MD *md = ssl_handshake_md(s);
760     size_t hashlen;
761     unsigned char key[EVP_MAX_KEY_LENGTH];
762     unsigned char *insecret;
763     unsigned char secret[EVP_MAX_MD_SIZE];
764     char *log_label;
765     size_t keylen, ivlen, taglen;
766     int ret = 0, l;
767     int direction = sending ? OSSL_RECORD_DIRECTION_WRITE
768                             : OSSL_RECORD_DIRECTION_READ;
769     unsigned char iv_intern[EVP_MAX_IV_LENGTH];
770     unsigned char *iv = iv_intern;
771 
772     if ((l = EVP_MD_get_size(md)) <= 0) {
773         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
774         return 0;
775     }
776     hashlen = (size_t)l;
777 
778     if (s->server == sending)
779         insecret = s->server_app_traffic_secret;
780     else
781         insecret = s->client_app_traffic_secret;
782 
783     if (!derive_secret_key_and_iv(s, md,
784                                   s->s3.tmp.new_sym_enc,
785                                   s->s3.tmp.new_mac_pkey_type, s->s3.tmp.new_hash,
786                                   insecret, NULL,
787                                   application_traffic,
788                                   sizeof(application_traffic) - 1, secret, key,
789                                   &keylen, &iv, &ivlen, &taglen)) {
790         /* SSLfatal() already called */
791         goto err;
792     }
793 
794     memcpy(insecret, secret, hashlen);
795 
796     if (!ssl_set_new_record_layer(s, s->version,
797                             direction,
798                             OSSL_RECORD_PROTECTION_LEVEL_APPLICATION,
799                             insecret, hashlen, key, keylen, iv, ivlen, NULL, 0,
800                             s->s3.tmp.new_sym_enc, taglen, NID_undef, NULL,
801                             NULL, md)) {
802         /* SSLfatal already called */
803         goto err;
804     }
805 
806     /* Call Key log on successful traffic secret update */
807     log_label = s->server == sending ? SERVER_APPLICATION_N_LABEL : CLIENT_APPLICATION_N_LABEL;
808     if (!ssl_log_secret(s, log_label, secret, hashlen)) {
809         /* SSLfatal() already called */
810         goto err;
811     }
812     ret = 1;
813  err:
814     OPENSSL_cleanse(key, sizeof(key));
815     OPENSSL_cleanse(secret, sizeof(secret));
816     if (iv != iv_intern)
817         OPENSSL_free(iv);
818     return ret;
819 }
820 
tls13_alert_code(int code)821 int tls13_alert_code(int code)
822 {
823     /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
824     if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
825         return code;
826 
827     return tls1_alert_code(code);
828 }
829 
tls13_export_keying_material(SSL_CONNECTION * s,unsigned char * out,size_t olen,const char * label,size_t llen,const unsigned char * context,size_t contextlen,int use_context)830 int tls13_export_keying_material(SSL_CONNECTION *s,
831                                  unsigned char *out, size_t olen,
832                                  const char *label, size_t llen,
833                                  const unsigned char *context,
834                                  size_t contextlen, int use_context)
835 {
836     unsigned char exportsecret[EVP_MAX_MD_SIZE];
837     /* ASCII: "exporter", in hex for EBCDIC compatibility */
838     static const unsigned char exporterlabel[] = "\x65\x78\x70\x6F\x72\x74\x65\x72";
839     unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
840     const EVP_MD *md = ssl_handshake_md(s);
841     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
842     unsigned int hashsize, datalen;
843     int ret = 0;
844 
845     if (ctx == NULL || md == NULL || !ossl_statem_export_allowed(s))
846         goto err;
847 
848     if (!use_context)
849         contextlen = 0;
850 
851     if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
852             || EVP_DigestUpdate(ctx, context, contextlen) <= 0
853             || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
854             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
855             || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
856             || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
857                                   (const unsigned char *)label, llen,
858                                   data, datalen, exportsecret, hashsize, 0)
859             || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
860                                   sizeof(exporterlabel) - 1, hash, hashsize,
861                                   out, olen, 0))
862         goto err;
863 
864     ret = 1;
865  err:
866     EVP_MD_CTX_free(ctx);
867     return ret;
868 }
869 
tls13_export_keying_material_early(SSL_CONNECTION * s,unsigned char * out,size_t olen,const char * label,size_t llen,const unsigned char * context,size_t contextlen)870 int tls13_export_keying_material_early(SSL_CONNECTION *s,
871                                        unsigned char *out, size_t olen,
872                                        const char *label, size_t llen,
873                                        const unsigned char *context,
874                                        size_t contextlen)
875 {
876     /* ASCII: "exporter", in hex for EBCDIC compatibility */
877     static const unsigned char exporterlabel[] = "\x65\x78\x70\x6F\x72\x74\x65\x72";
878     unsigned char exportsecret[EVP_MAX_MD_SIZE];
879     unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
880     const EVP_MD *md;
881     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
882     unsigned int hashsize, datalen;
883     int ret = 0;
884     const SSL_CIPHER *sslcipher;
885 
886     if (ctx == NULL || !ossl_statem_export_early_allowed(s))
887         goto err;
888 
889     if (!s->server && s->max_early_data > 0
890             && s->session->ext.max_early_data == 0)
891         sslcipher = SSL_SESSION_get0_cipher(s->psksession);
892     else
893         sslcipher = SSL_SESSION_get0_cipher(s->session);
894 
895     md = ssl_md(SSL_CONNECTION_GET_CTX(s), sslcipher->algorithm2);
896 
897     /*
898      * Calculate the hash value and store it in |data|. The reason why
899      * the empty string is used is that the definition of TLS-Exporter
900      * is like so:
901      *
902      * TLS-Exporter(label, context_value, key_length) =
903      *     HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
904      *                       "exporter", Hash(context_value), key_length)
905      *
906      * Derive-Secret(Secret, Label, Messages) =
907      *       HKDF-Expand-Label(Secret, Label,
908      *                         Transcript-Hash(Messages), Hash.length)
909      *
910      * Here Transcript-Hash is the cipher suite hash algorithm.
911      */
912     if (md == NULL
913             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
914             || EVP_DigestUpdate(ctx, context, contextlen) <= 0
915             || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
916             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
917             || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
918             || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
919                                   (const unsigned char *)label, llen,
920                                   data, datalen, exportsecret, hashsize, 0)
921             || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
922                                   sizeof(exporterlabel) - 1, hash, hashsize,
923                                   out, olen, 0))
924         goto err;
925 
926     ret = 1;
927  err:
928     EVP_MD_CTX_free(ctx);
929     return ret;
930 }
931