ssl/tls13_enc.c

   1 /*
   2  * Copyright 2016-2021 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 #ifdef CHARSET_EBCDIC
  22 static const unsigned char label_prefix[] = { 0x74, 0x6C, 0x73, 0x31, 0x33, 0x20, 0x00 };
  23 #else
  24 static const unsigned char label_prefix[] = "tls13 ";
  25 #endif
  26
  27 /*
  28  * Given a |secret|; a |label| of length |labellen|; and |data| of length
  29  * |datalen| (e.g. typically a hash of the handshake messages), derive a new
  30  * secret |outlen| bytes long and store it in the location pointed to be |out|.
  31  * The |data| value may be zero length. Any errors will be treated as fatal if
  32  * |fatal| is set. Returns 1 on success  0 on failure.
  33  */
  34 int tls13_hkdf_expand(SSL *s, const EVP_MD *md, 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 fatal)
  38 {
  39     EVP_KDF *kdf = EVP_KDF_fetch(s->ctx->libctx, OSSL_KDF_NAME_TLS1_3_KDF,
  40                                  s->ctx->propq);
  41     EVP_KDF_CTX *kctx;
  42     OSSL_PARAM params[7], *p = params;
  43     int mode = EVP_PKEY_HKDEF_MODE_EXPAND_ONLY;
  44     const char *mdname = EVP_MD_get0_name(md);
  45     int ret;
  46     size_t hashlen;
  47
  48     kctx = EVP_KDF_CTX_new(kdf);
  49     EVP_KDF_free(kdf);
  50     if (kctx == NULL)
  51         return 0;
  52
  53     if (labellen > TLS13_MAX_LABEL_LEN) {
  54         if (fatal) {
  55             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
  56         } else {
  57             /*
  58              * Probably we have been called from SSL_export_keying_material(),
  59              * or SSL_export_keying_material_early().
  60              */
  61             ERR_raise(ERR_LIB_SSL, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
  62         }
  63         EVP_KDF_CTX_free(kctx);
  64         return 0;
  65     }
  66
  67     if ((ret = EVP_MD_get_size(md)) <= 0) {
  68         EVP_KDF_CTX_free(kctx);
  69         if (fatal)
  70             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
  71         else
  72             ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
  73         return 0;
  74     }
  75     hashlen = (size_t)ret;
  76
  77     *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
  78     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
  79                                             (char *)mdname, 0);
  80     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
  81                                              (unsigned char *)secret, hashlen);
  82     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PREFIX,
  83                                              (unsigned char *)label_prefix,
  84                                              sizeof(label_prefix) - 1);
  85     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_LABEL,
  86                                              (unsigned char *)label, labellen);
  87     if (data != NULL)
  88         *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_DATA,
  89                                                  (unsigned char *)data,
  90                                                  datalen);
  91     *p++ = OSSL_PARAM_construct_end();
  92
  93     ret = EVP_KDF_derive(kctx, out, outlen, params) <= 0;
  94     EVP_KDF_CTX_free(kctx);
  95
  96     if (ret != 0) {
  97         if (fatal)
  98             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
  99         else
 100             ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
 101     }
 102
 103     return ret == 0;
 104 }
 105
 106 /*
 107  * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
 108  * success  0 on failure.
 109  */
 110 int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret,
 111                      unsigned char *key, size_t keylen)
 112 {
 113 #ifdef CHARSET_EBCDIC
 114   static const unsigned char keylabel[] ={ 0x6B, 0x65, 0x79, 0x00 };
 115 #else
 116   static const unsigned char keylabel[] = "key";
 117 #endif
 118
 119     return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
 120                              NULL, 0, key, keylen, 1);
 121 }
 122
 123 /*
 124  * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
 125  * success  0 on failure.
 126  */
 127 int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret,
 128                     unsigned char *iv, size_t ivlen)
 129 {
 130 #ifdef CHARSET_EBCDIC
 131   static const unsigned char ivlabel[] = { 0x69, 0x76, 0x00 };
 132 #else
 133   static const unsigned char ivlabel[] = "iv";
 134 #endif
 135
 136     return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
 137                              NULL, 0, iv, ivlen, 1);
 138 }
 139
 140 int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
 141                              const unsigned char *secret,
 142                              unsigned char *fin, size_t finlen)
 143 {
 144 #ifdef CHARSET_EBCDIC
 145   static const unsigned char finishedlabel[] = { 0x66, 0x69, 0x6E, 0x69, 0x73, 0x68, 0x65, 0x64, 0x00 };
 146 #else
 147   static const unsigned char finishedlabel[] = "finished";
 148 #endif
 149
 150     return tls13_hkdf_expand(s, md, secret, finishedlabel,
 151                              sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1);
 152 }
 153
 154 /*
 155  * Given the previous secret |prevsecret| and a new input secret |insecret| of
 156  * length |insecretlen|, generate a new secret and store it in the location
 157  * pointed to by |outsecret|. Returns 1 on success  0 on failure.
 158  */
 159 int tls13_generate_secret(SSL *s, const EVP_MD *md,
 160                           const unsigned char *prevsecret,
 161                           const unsigned char *insecret,
 162                           size_t insecretlen,
 163                           unsigned char *outsecret)
 164 {
 165     size_t mdlen;
 166     int mdleni;
 167     int ret;
 168     EVP_KDF *kdf;
 169     EVP_KDF_CTX *kctx;
 170     OSSL_PARAM params[7], *p = params;
 171     int mode = EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY;
 172     const char *mdname = EVP_MD_get0_name(md);
 173 #ifdef CHARSET_EBCDIC
 174     static const char derived_secret_label[] = { 0x64, 0x65, 0x72, 0x69, 0x76, 0x65, 0x64, 0x00 };
 175 #else
 176     static const char derived_secret_label[] = "derived";
 177 #endif
 178
 179     kdf = EVP_KDF_fetch(s->ctx->libctx, OSSL_KDF_NAME_TLS1_3_KDF, s->ctx->propq);
 180     kctx = EVP_KDF_CTX_new(kdf);
 181     EVP_KDF_free(kdf);
 182     if (kctx == NULL) {
 183         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 184         return 0;
 185     }
 186
 187     mdleni = EVP_MD_get_size(md);
 188     /* Ensure cast to size_t is safe */
 189     if (!ossl_assert(mdleni >= 0)) {
 190         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 191         EVP_KDF_CTX_free(kctx);
 192         return 0;
 193     }
 194     mdlen = (size_t)mdleni;
 195
 196     *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
 197     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
 198                                             (char *)mdname, 0);
 199     if (insecret != NULL)
 200         *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
 201                                                  (unsigned char *)insecret,
 202                                                  insecretlen);
 203     if (prevsecret != NULL)
 204         *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT,
 205                                                  (unsigned char *)prevsecret, mdlen);
 206     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PREFIX,
 207                                              (unsigned char *)label_prefix,
 208                                              sizeof(label_prefix) - 1);
 209     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_LABEL,
 210                                              (unsigned char *)derived_secret_label,
 211                                              sizeof(derived_secret_label) - 1);
 212     *p++ = OSSL_PARAM_construct_end();
 213
 214     ret = EVP_KDF_derive(kctx, outsecret, mdlen, params) <= 0;
 215
 216     if (ret != 0)
 217         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 218
 219     EVP_KDF_CTX_free(kctx);
 220     return ret == 0;
 221 }
 222
 223 /*
 224  * Given an input secret |insecret| of length |insecretlen| generate the
 225  * handshake secret. This requires the early secret to already have been
 226  * generated. Returns 1 on success  0 on failure.
 227  */
 228 int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret,
 229                                 size_t insecretlen)
 230 {
 231     /* Calls SSLfatal() if required */
 232     return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
 233                                  insecret, insecretlen,
 234                                  (unsigned char *)&s->handshake_secret);
 235 }
 236
 237 /*
 238  * Given the handshake secret |prev| of length |prevlen| generate the master
 239  * secret and store its length in |*secret_size|. Returns 1 on success  0 on
 240  * failure.
 241  */
 242 int tls13_generate_master_secret(SSL *s, unsigned char *out,
 243                                  unsigned char *prev, size_t prevlen,
 244                                  size_t *secret_size)
 245 {
 246     const EVP_MD *md = ssl_handshake_md(s);
 247
 248     *secret_size = EVP_MD_get_size(md);
 249     /* Calls SSLfatal() if required */
 250     return tls13_generate_secret(s, md, prev, NULL, 0, out);
 251 }
 252
 253 /*
 254  * Generates the mac for the Finished message. Returns the length of the MAC or
 255  * 0 on error.
 256  */
 257 size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
 258                              unsigned char *out)
 259 {
 260     const char *mdname = EVP_MD_get0_name(ssl_handshake_md(s));
 261     unsigned char hash[EVP_MAX_MD_SIZE];
 262     unsigned char finsecret[EVP_MAX_MD_SIZE];
 263     unsigned char *key = NULL;
 264     size_t len = 0, hashlen;
 265     OSSL_PARAM params[2], *p = params;
 266
 267     /* Safe to cast away const here since we're not "getting" any data */
 268     if (s->ctx->propq != NULL)
 269         *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_PROPERTIES,
 270                                                 (char *)s->ctx->propq,
 271                                                 0);
 272     *p = OSSL_PARAM_construct_end();
 273
 274     if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
 275         /* SSLfatal() already called */
 276         goto err;
 277     }
 278
 279     if (str == s->method->ssl3_enc->server_finished_label) {
 280         key = s->server_finished_secret;
 281     } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
 282         key = s->client_finished_secret;
 283     } else {
 284         if (!tls13_derive_finishedkey(s, ssl_handshake_md(s),
 285                                       s->client_app_traffic_secret,
 286                                       finsecret, hashlen))
 287             goto err;
 288         key = finsecret;
 289     }
 290
 291     if (!EVP_Q_mac(s->ctx->libctx, "HMAC", s->ctx->propq, mdname,
 292                    params, key, hashlen, hash, hashlen,
 293                    /* outsize as per sizeof(peer_finish_md) */
 294                    out, EVP_MAX_MD_SIZE * 2, &len)) {
 295         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 296         goto err;
 297     }
 298
 299  err:
 300     OPENSSL_cleanse(finsecret, sizeof(finsecret));
 301     return len;
 302 }
 303
 304 /*
 305  * There isn't really a key block in TLSv1.3, but we still need this function
 306  * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
 307  */
 308 int tls13_setup_key_block(SSL *s)
 309 {
 310     const EVP_CIPHER *c;
 311     const EVP_MD *hash;
 312
 313     s->session->cipher = s->s3.tmp.new_cipher;
 314     if (!ssl_cipher_get_evp(s->ctx, s->session, &c, &hash, NULL, NULL, NULL,
 315                             0)) {
 316         /* Error is already recorded */
 317         SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
 318         return 0;
 319     }
 320
 321     ssl_evp_cipher_free(s->s3.tmp.new_sym_enc);
 322     s->s3.tmp.new_sym_enc = c;
 323     ssl_evp_md_free(s->s3.tmp.new_hash);
 324     s->s3.tmp.new_hash = hash;
 325
 326     return 1;
 327 }
 328
 329 static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md,
 330                                     const EVP_CIPHER *ciph,
 331                                     const unsigned char *insecret,
 332                                     const unsigned char *hash,
 333                                     const unsigned char *label,
 334                                     size_t labellen, unsigned char *secret,
 335                                     unsigned char *key, unsigned char *iv,
 336                                     EVP_CIPHER_CTX *ciph_ctx)
 337 {
 338     size_t ivlen, keylen, taglen;
 339     int hashleni = EVP_MD_get_size(md);
 340     size_t hashlen;
 341
 342     /* Ensure cast to size_t is safe */
 343     if (!ossl_assert(hashleni >= 0)) {
 344         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
 345         return 0;
 346     }
 347     hashlen = (size_t)hashleni;
 348
 349     if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
 350                            secret, hashlen, 1)) {
 351         /* SSLfatal() already called */
 352         return 0;
 353     }
 354
 355     keylen = EVP_CIPHER_get_key_length(ciph);
 356     if (EVP_CIPHER_get_mode(ciph) == EVP_CIPH_CCM_MODE) {
 357         uint32_t algenc;
 358
 359         ivlen = EVP_CCM_TLS_IV_LEN;
 360         if (s->s3.tmp.new_cipher != NULL) {
 361             algenc = s->s3.tmp.new_cipher->algorithm_enc;
 362         } else if (s->session->cipher != NULL) {
 363             /* We've not selected a cipher yet - we must be doing early data */
 364             algenc = s->session->cipher->algorithm_enc;
 365         } else if (s->psksession != NULL && s->psksession->cipher != NULL) {
 366             /* We must be doing early data with out-of-band PSK */
 367             algenc = s->psksession->cipher->algorithm_enc;
 368         } else {
 369             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
 370             return 0;
 371         }
 372         if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
 373             taglen = EVP_CCM8_TLS_TAG_LEN;
 374          else
 375             taglen = EVP_CCM_TLS_TAG_LEN;
 376     } else {
 377         ivlen = EVP_CIPHER_get_iv_length(ciph);
 378         taglen = 0;
 379     }
 380
 381     if (!tls13_derive_key(s, md, secret, key, keylen)
 382             || !tls13_derive_iv(s, md, secret, iv, ivlen)) {
 383         /* SSLfatal() already called */
 384         return 0;
 385     }
 386
 387     if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0
 388         || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
 389         || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG,
 390                                                 taglen, NULL))
 391         || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
 392         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
 393         return 0;
 394     }
 395
 396     return 1;
 397 }
 398
 399 int tls13_change_cipher_state(SSL *s, int which)
 400 {
 401 #ifdef CHARSET_EBCDIC
 402   static const unsigned char client_early_traffic[]       = {0x63, 0x20, 0x65, 0x20,       /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 403   static const unsigned char client_handshake_traffic[]   = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 404   static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 405   static const unsigned char server_handshake_traffic[]   = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 406   static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 407   static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20,                    /* master*/  0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
 408   static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20,                  /* master*/  0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
 409   static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20,  /* master*/  0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
 410 #else
 411     static const unsigned char client_early_traffic[] = "c e traffic";
 412     static const unsigned char client_handshake_traffic[] = "c hs traffic";
 413     static const unsigned char client_application_traffic[] = "c ap traffic";
 414     static const unsigned char server_handshake_traffic[] = "s hs traffic";
 415     static const unsigned char server_application_traffic[] = "s ap traffic";
 416     static const unsigned char exporter_master_secret[] = "exp master";
 417     static const unsigned char resumption_master_secret[] = "res master";
 418     static const unsigned char early_exporter_master_secret[] = "e exp master";
 419 #endif
 420     unsigned char *iv;
 421     unsigned char key[EVP_MAX_KEY_LENGTH];
 422     unsigned char secret[EVP_MAX_MD_SIZE];
 423     unsigned char hashval[EVP_MAX_MD_SIZE];
 424     unsigned char *hash = hashval;
 425     unsigned char *insecret;
 426     unsigned char *finsecret = NULL;
 427     const char *log_label = NULL;
 428     EVP_CIPHER_CTX *ciph_ctx;
 429     size_t finsecretlen = 0;
 430     const unsigned char *label;
 431     size_t labellen, hashlen = 0;
 432     int ret = 0;
 433     const EVP_MD *md = NULL;
 434     const EVP_CIPHER *cipher = NULL;
 435 #if !defined(OPENSSL_NO_KTLS) && defined(OPENSSL_KTLS_TLS13)
 436     ktls_crypto_info_t crypto_info;
 437     BIO *bio;
 438 #endif
 439
 440     if (which & SSL3_CC_READ) {
 441         if (s->enc_read_ctx != NULL) {
 442             EVP_CIPHER_CTX_reset(s->enc_read_ctx);
 443         } else {
 444             s->enc_read_ctx = EVP_CIPHER_CTX_new();
 445             if (s->enc_read_ctx == NULL) {
 446                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
 447                 goto err;
 448             }
 449         }
 450         ciph_ctx = s->enc_read_ctx;
 451         iv = s->read_iv;
 452
 453         RECORD_LAYER_reset_read_sequence(&s->rlayer);
 454     } else {
 455         s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
 456         if (s->enc_write_ctx != NULL) {
 457             EVP_CIPHER_CTX_reset(s->enc_write_ctx);
 458         } else {
 459             s->enc_write_ctx = EVP_CIPHER_CTX_new();
 460             if (s->enc_write_ctx == NULL) {
 461                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
 462                 goto err;
 463             }
 464         }
 465         ciph_ctx = s->enc_write_ctx;
 466         iv = s->write_iv;
 467
 468         RECORD_LAYER_reset_write_sequence(&s->rlayer);
 469     }
 470
 471     if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
 472             || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
 473         if (which & SSL3_CC_EARLY) {
 474             EVP_MD_CTX *mdctx = NULL;
 475             long handlen;
 476             void *hdata;
 477             unsigned int hashlenui;
 478             const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
 479
 480             insecret = s->early_secret;
 481             label = client_early_traffic;
 482             labellen = sizeof(client_early_traffic) - 1;
 483             log_label = CLIENT_EARLY_LABEL;
 484
 485             handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
 486             if (handlen <= 0) {
 487                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_HANDSHAKE_LENGTH);
 488                 goto err;
 489             }
 490
 491             if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
 492                     && s->max_early_data > 0
 493                     && s->session->ext.max_early_data == 0) {
 494                 /*
 495                  * If we are attempting to send early data, and we've decided to
 496                  * actually do it but max_early_data in s->session is 0 then we
 497                  * must be using an external PSK.
 498                  */
 499                 if (!ossl_assert(s->psksession != NULL
 500                         && s->max_early_data ==
 501                            s->psksession->ext.max_early_data)) {
 502                     SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 503                     goto err;
 504                 }
 505                 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
 506             }
 507             if (sslcipher == NULL) {
 508                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_PSK);
 509                 goto err;
 510             }
 511
 512             /*
 513              * We need to calculate the handshake digest using the digest from
 514              * the session. We haven't yet selected our ciphersuite so we can't
 515              * use ssl_handshake_md().
 516              */
 517             mdctx = EVP_MD_CTX_new();
 518             if (mdctx == NULL) {
 519                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
 520                 goto err;
 521             }
 522
 523             /*
 524              * This ups the ref count on cipher so we better make sure we free
 525              * it again
 526              */
 527             if (!ssl_cipher_get_evp_cipher(s->ctx, sslcipher, &cipher)) {
 528                 /* Error is already recorded */
 529                 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
 530                 EVP_MD_CTX_free(mdctx);
 531                 goto err;
 532             }
 533
 534             md = ssl_md(s->ctx, sslcipher->algorithm2);
 535             if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
 536                     || !EVP_DigestUpdate(mdctx, hdata, handlen)
 537                     || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
 538                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 539                 EVP_MD_CTX_free(mdctx);
 540                 goto err;
 541             }
 542             hashlen = hashlenui;
 543             EVP_MD_CTX_free(mdctx);
 544
 545             if (!tls13_hkdf_expand(s, md, insecret,
 546                                    early_exporter_master_secret,
 547                                    sizeof(early_exporter_master_secret) - 1,
 548                                    hashval, hashlen,
 549                                    s->early_exporter_master_secret, hashlen,
 550                                    1)) {
 551                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 552                 goto err;
 553             }
 554
 555             if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
 556                                 s->early_exporter_master_secret, hashlen)) {
 557                 /* SSLfatal() already called */
 558                 goto err;
 559             }
 560         } else if (which & SSL3_CC_HANDSHAKE) {
 561             insecret = s->handshake_secret;
 562             finsecret = s->client_finished_secret;
 563             finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
 564             label = client_handshake_traffic;
 565             labellen = sizeof(client_handshake_traffic) - 1;
 566             log_label = CLIENT_HANDSHAKE_LABEL;
 567             /*
 568              * The handshake hash used for the server read/client write handshake
 569              * traffic secret is the same as the hash for the server
 570              * write/client read handshake traffic secret. However, if we
 571              * processed early data then we delay changing the server
 572              * read/client write cipher state until later, and the handshake
 573              * hashes have moved on. Therefore we use the value saved earlier
 574              * when we did the server write/client read change cipher state.
 575              */
 576             hash = s->handshake_traffic_hash;
 577         } else {
 578             insecret = s->master_secret;
 579             label = client_application_traffic;
 580             labellen = sizeof(client_application_traffic) - 1;
 581             log_label = CLIENT_APPLICATION_LABEL;
 582             /*
 583              * For this we only use the handshake hashes up until the server
 584              * Finished hash. We do not include the client's Finished, which is
 585              * what ssl_handshake_hash() would give us. Instead we use the
 586              * previously saved value.
 587              */
 588             hash = s->server_finished_hash;
 589         }
 590     } else {
 591         /* Early data never applies to client-read/server-write */
 592         if (which & SSL3_CC_HANDSHAKE) {
 593             insecret = s->handshake_secret;
 594             finsecret = s->server_finished_secret;
 595             finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
 596             label = server_handshake_traffic;
 597             labellen = sizeof(server_handshake_traffic) - 1;
 598             log_label = SERVER_HANDSHAKE_LABEL;
 599         } else {
 600             insecret = s->master_secret;
 601             label = server_application_traffic;
 602             labellen = sizeof(server_application_traffic) - 1;
 603             log_label = SERVER_APPLICATION_LABEL;
 604         }
 605     }
 606
 607     if (!(which & SSL3_CC_EARLY)) {
 608         md = ssl_handshake_md(s);
 609         cipher = s->s3.tmp.new_sym_enc;
 610         if (!ssl3_digest_cached_records(s, 1)
 611                 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
 612             /* SSLfatal() already called */;
 613             goto err;
 614         }
 615     }
 616
 617     /*
 618      * Save the hash of handshakes up to now for use when we calculate the
 619      * client application traffic secret
 620      */
 621     if (label == server_application_traffic)
 622         memcpy(s->server_finished_hash, hashval, hashlen);
 623
 624     if (label == server_handshake_traffic)
 625         memcpy(s->handshake_traffic_hash, hashval, hashlen);
 626
 627     if (label == client_application_traffic) {
 628         /*
 629          * We also create the resumption master secret, but this time use the
 630          * hash for the whole handshake including the Client Finished
 631          */
 632         if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
 633                                resumption_master_secret,
 634                                sizeof(resumption_master_secret) - 1,
 635                                hashval, hashlen, s->resumption_master_secret,
 636                                hashlen, 1)) {
 637             /* SSLfatal() already called */
 638             goto err;
 639         }
 640     }
 641
 642     /* check whether cipher is known */
 643     if (!ossl_assert(cipher != NULL))
 644         goto err;
 645
 646     if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
 647                                   insecret, hash, label, labellen, secret, key,
 648                                   iv, ciph_ctx)) {
 649         /* SSLfatal() already called */
 650         goto err;
 651     }
 652
 653     if (label == server_application_traffic) {
 654         memcpy(s->server_app_traffic_secret, secret, hashlen);
 655         /* Now we create the exporter master secret */
 656         if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
 657                                exporter_master_secret,
 658                                sizeof(exporter_master_secret) - 1,
 659                                hash, hashlen, s->exporter_master_secret,
 660                                hashlen, 1)) {
 661             /* SSLfatal() already called */
 662             goto err;
 663         }
 664
 665         if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
 666                             hashlen)) {
 667             /* SSLfatal() already called */
 668             goto err;
 669         }
 670     } else if (label == client_application_traffic)
 671         memcpy(s->client_app_traffic_secret, secret, hashlen);
 672
 673     if (!ssl_log_secret(s, log_label, secret, hashlen)) {
 674         /* SSLfatal() already called */
 675         goto err;
 676     }
 677
 678     if (finsecret != NULL
 679             && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
 680                                          finsecret, finsecretlen)) {
 681         /* SSLfatal() already called */
 682         goto err;
 683     }
 684
 685     if (!s->server && label == client_early_traffic)
 686         s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
 687     else
 688         s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
 689 #ifndef OPENSSL_NO_KTLS
 690 # if defined(OPENSSL_KTLS_TLS13)
 691     if (!(which & SSL3_CC_WRITE)
 692             || !(which & SSL3_CC_APPLICATION)
 693             || (s->options & SSL_OP_ENABLE_KTLS) == 0)
 694         goto skip_ktls;
 695
 696     /* ktls supports only the maximum fragment size */
 697     if (ssl_get_max_send_fragment(s) != SSL3_RT_MAX_PLAIN_LENGTH)
 698         goto skip_ktls;
 699
 700     /* ktls does not support record padding */
 701     if (s->record_padding_cb != NULL)
 702         goto skip_ktls;
 703
 704     /* check that cipher is supported */
 705     if (!ktls_check_supported_cipher(s, cipher, ciph_ctx))
 706         goto skip_ktls;
 707
 708     bio = s->wbio;
 709
 710     if (!ossl_assert(bio != NULL)) {
 711         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 712         goto err;
 713     }
 714
 715     /* All future data will get encrypted by ktls. Flush the BIO or skip ktls */
 716     if (BIO_flush(bio) <= 0)
 717         goto skip_ktls;
 718
 719     /* configure kernel crypto structure */
 720     if (!ktls_configure_crypto(s, cipher, ciph_ctx,
 721                                RECORD_LAYER_get_write_sequence(&s->rlayer),
 722                                &crypto_info, NULL, iv, key, NULL, 0))
 723         goto skip_ktls;
 724
 725     /* ktls works with user provided buffers directly */
 726     if (BIO_set_ktls(bio, &crypto_info, which & SSL3_CC_WRITE))
 727         ssl3_release_write_buffer(s);
 728 skip_ktls:
 729 # endif
 730 #endif
 731     ret = 1;
 732  err:
 733     if ((which & SSL3_CC_EARLY) != 0) {
 734         /* We up-refed this so now we need to down ref */
 735         ssl_evp_cipher_free(cipher);
 736     }
 737     OPENSSL_cleanse(key, sizeof(key));
 738     OPENSSL_cleanse(secret, sizeof(secret));
 739     return ret;
 740 }
 741
 742 int tls13_update_key(SSL *s, int sending)
 743 {
 744 #ifdef CHARSET_EBCDIC
 745   static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00};
 746 #else
 747   static const unsigned char application_traffic[] = "traffic upd";
 748 #endif
 749     const EVP_MD *md = ssl_handshake_md(s);
 750     size_t hashlen = EVP_MD_get_size(md);
 751     unsigned char key[EVP_MAX_KEY_LENGTH];
 752     unsigned char *insecret, *iv;
 753     unsigned char secret[EVP_MAX_MD_SIZE];
 754     EVP_CIPHER_CTX *ciph_ctx;
 755     int ret = 0;
 756
 757     if (s->server == sending)
 758         insecret = s->server_app_traffic_secret;
 759     else
 760         insecret = s->client_app_traffic_secret;
 761
 762     if (sending) {
 763         s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
 764         iv = s->write_iv;
 765         ciph_ctx = s->enc_write_ctx;
 766         RECORD_LAYER_reset_write_sequence(&s->rlayer);
 767     } else {
 768         iv = s->read_iv;
 769         ciph_ctx = s->enc_read_ctx;
 770         RECORD_LAYER_reset_read_sequence(&s->rlayer);
 771     }
 772
 773     if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s),
 774                                   s->s3.tmp.new_sym_enc, insecret, NULL,
 775                                   application_traffic,
 776                                   sizeof(application_traffic) - 1, secret, key,
 777                                   iv, ciph_ctx)) {
 778         /* SSLfatal() already called */
 779         goto err;
 780     }
 781
 782     memcpy(insecret, secret, hashlen);
 783
 784     s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
 785     ret = 1;
 786  err:
 787     OPENSSL_cleanse(key, sizeof(key));
 788     OPENSSL_cleanse(secret, sizeof(secret));
 789     return ret;
 790 }
 791
 792 int tls13_alert_code(int code)
 793 {
 794     /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
 795     if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
 796         return code;
 797
 798     return tls1_alert_code(code);
 799 }
 800
 801 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
 802                                  const char *label, size_t llen,
 803                                  const unsigned char *context,
 804                                  size_t contextlen, int use_context)
 805 {
 806     unsigned char exportsecret[EVP_MAX_MD_SIZE];
 807 #ifdef CHARSET_EBCDIC
 808     static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
 809 #else
 810     static const unsigned char exporterlabel[] = "exporter";
 811 #endif
 812     unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
 813     const EVP_MD *md = ssl_handshake_md(s);
 814     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 815     unsigned int hashsize, datalen;
 816     int ret = 0;
 817
 818     if (ctx == NULL || !ossl_statem_export_allowed(s))
 819         goto err;
 820
 821     if (!use_context)
 822         contextlen = 0;
 823
 824     if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
 825             || EVP_DigestUpdate(ctx, context, contextlen) <= 0
 826             || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
 827             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
 828             || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
 829             || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
 830                                   (const unsigned char *)label, llen,
 831                                   data, datalen, exportsecret, hashsize, 0)
 832             || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
 833                                   sizeof(exporterlabel) - 1, hash, hashsize,
 834                                   out, olen, 0))
 835         goto err;
 836
 837     ret = 1;
 838  err:
 839     EVP_MD_CTX_free(ctx);
 840     return ret;
 841 }
 842
 843 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen,
 844                                        const char *label, size_t llen,
 845                                        const unsigned char *context,
 846                                        size_t contextlen)
 847 {
 848 #ifdef CHARSET_EBCDIC
 849   static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
 850 #else
 851   static const unsigned char exporterlabel[] = "exporter";
 852 #endif
 853     unsigned char exportsecret[EVP_MAX_MD_SIZE];
 854     unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
 855     const EVP_MD *md;
 856     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 857     unsigned int hashsize, datalen;
 858     int ret = 0;
 859     const SSL_CIPHER *sslcipher;
 860
 861     if (ctx == NULL || !ossl_statem_export_early_allowed(s))
 862         goto err;
 863
 864     if (!s->server && s->max_early_data > 0
 865             && s->session->ext.max_early_data == 0)
 866         sslcipher = SSL_SESSION_get0_cipher(s->psksession);
 867     else
 868         sslcipher = SSL_SESSION_get0_cipher(s->session);
 869
 870     md = ssl_md(s->ctx, sslcipher->algorithm2);
 871
 872     /*
 873      * Calculate the hash value and store it in |data|. The reason why
 874      * the empty string is used is that the definition of TLS-Exporter
 875      * is like so:
 876      *
 877      * TLS-Exporter(label, context_value, key_length) =
 878      *     HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
 879      *                       "exporter", Hash(context_value), key_length)
 880      *
 881      * Derive-Secret(Secret, Label, Messages) =
 882      *       HKDF-Expand-Label(Secret, Label,
 883      *                         Transcript-Hash(Messages), Hash.length)
 884      *
 885      * Here Transcript-Hash is the cipher suite hash algorithm.
 886      */
 887     if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
 888             || EVP_DigestUpdate(ctx, context, contextlen) <= 0
 889             || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
 890             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
 891             || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
 892             || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
 893                                   (const unsigned char *)label, llen,
 894                                   data, datalen, exportsecret, hashsize, 0)
 895             || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
 896                                   sizeof(exporterlabel) - 1, hash, hashsize,
 897                                   out, olen, 0))
 898         goto err;
 899
 900     ret = 1;
 901  err:
 902     EVP_MD_CTX_free(ctx);
 903     return ret;
 904 }