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 /* Always filled with zeros */
  22 static const unsigned char default_zeros[EVP_MAX_MD_SIZE];
  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  */
  31 int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret,
  32                              const unsigned char *label, size_t labellen,
  33                              const unsigned char *data, size_t datalen,
  34                              unsigned char *out, size_t outlen, int fatal)
  35 {
  36 #ifdef CHARSET_EBCDIC
  37     static const unsigned char label_prefix[] = { 0x74, 0x6C, 0x73, 0x31, 0x33, 0x20, 0x00 };
  38 #else
  39     static const unsigned char label_prefix[] = "tls13 ";
  40 #endif
  41     EVP_KDF *kdf = EVP_KDF_fetch(s->ctx->libctx, OSSL_KDF_NAME_HKDF,
  42                                  s->ctx->propq);
  43     EVP_KDF_CTX *kctx;
  44     OSSL_PARAM params[5], *p = params;
  45     int mode = EVP_PKEY_HKDEF_MODE_EXPAND_ONLY;
  46     const char *mdname = EVP_MD_get0_name(md);
  47     int ret;
  48     size_t hkdflabellen;
  49     size_t hashlen;
  50     /*
  51      * 2 bytes for length of derived secret + 1 byte for length of combined
  52      * prefix and label + bytes for the label itself + 1 byte length of hash
  53      * + bytes for the hash itself
  54      */
  55     unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t)
  56                             + (sizeof(label_prefix) - 1) + TLS13_MAX_LABEL_LEN
  57                             + 1 + EVP_MAX_MD_SIZE];
  58     WPACKET pkt;
  59
  60     kctx = EVP_KDF_CTX_new(kdf);
  61     EVP_KDF_free(kdf);
  62     if (kctx == NULL)
  63         return 0;
  64
  65     if (labellen > TLS13_MAX_LABEL_LEN) {
  66         if (fatal) {
  67             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
  68         } else {
  69             /*
  70              * Probably we have been called from SSL_export_keying_material(),
  71              * or SSL_export_keying_material_early().
  72              */
  73             ERR_raise(ERR_LIB_SSL, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
  74         }
  75         EVP_KDF_CTX_free(kctx);
  76         return 0;
  77     }
  78
  79     hashlen = EVP_MD_get_size(md);
  80
  81     if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0)
  82             || !WPACKET_put_bytes_u16(&pkt, outlen)
  83             || !WPACKET_start_sub_packet_u8(&pkt)
  84             || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1)
  85             || !WPACKET_memcpy(&pkt, label, labellen)
  86             || !WPACKET_close(&pkt)
  87             || !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen)
  88             || !WPACKET_get_total_written(&pkt, &hkdflabellen)
  89             || !WPACKET_finish(&pkt)) {
  90         EVP_KDF_CTX_free(kctx);
  91         WPACKET_cleanup(&pkt);
  92         if (fatal)
  93             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
  94         else
  95             ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
  96         return 0;
  97     }
  98
  99     *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
 100     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
 101                                             (char *)mdname, 0);
 102     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
 103                                              (unsigned char *)secret, hashlen);
 104     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_INFO,
 105                                              hkdflabel, hkdflabellen);
 106     *p++ = OSSL_PARAM_construct_end();
 107
 108     ret = EVP_KDF_derive(kctx, out, outlen, params) <= 0;
 109
 110     EVP_KDF_CTX_free(kctx);
 111
 112     if (ret != 0) {
 113         if (fatal)
 114             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 115         else
 116             ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
 117     }
 118
 119     return ret == 0;
 120 }
 121
 122 /*
 123  * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
 124  * success  0 on failure.
 125  */
 126 int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret,
 127                      unsigned char *key, size_t keylen)
 128 {
 129 #ifdef CHARSET_EBCDIC
 130   static const unsigned char keylabel[] ={ 0x6B, 0x65, 0x79, 0x00 };
 131 #else
 132   static const unsigned char keylabel[] = "key";
 133 #endif
 134
 135     return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
 136                              NULL, 0, key, keylen, 1);
 137 }
 138
 139 /*
 140  * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
 141  * success  0 on failure.
 142  */
 143 int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret,
 144                     unsigned char *iv, size_t ivlen)
 145 {
 146 #ifdef CHARSET_EBCDIC
 147   static const unsigned char ivlabel[] = { 0x69, 0x76, 0x00 };
 148 #else
 149   static const unsigned char ivlabel[] = "iv";
 150 #endif
 151
 152     return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
 153                              NULL, 0, iv, ivlen, 1);
 154 }
 155
 156 int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
 157                              const unsigned char *secret,
 158                              unsigned char *fin, size_t finlen)
 159 {
 160 #ifdef CHARSET_EBCDIC
 161   static const unsigned char finishedlabel[] = { 0x66, 0x69, 0x6E, 0x69, 0x73, 0x68, 0x65, 0x64, 0x00 };
 162 #else
 163   static const unsigned char finishedlabel[] = "finished";
 164 #endif
 165
 166     return tls13_hkdf_expand(s, md, secret, finishedlabel,
 167                              sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1);
 168 }
 169
 170 /*
 171  * Given the previous secret |prevsecret| and a new input secret |insecret| of
 172  * length |insecretlen|, generate a new secret and store it in the location
 173  * pointed to by |outsecret|. Returns 1 on success  0 on failure.
 174  */
 175 int tls13_generate_secret(SSL *s, const EVP_MD *md,
 176                           const unsigned char *prevsecret,
 177                           const unsigned char *insecret,
 178                           size_t insecretlen,
 179                           unsigned char *outsecret)
 180 {
 181     size_t mdlen, prevsecretlen;
 182     int mdleni;
 183     int ret;
 184     EVP_KDF *kdf;
 185     EVP_KDF_CTX *kctx;
 186     OSSL_PARAM params[5], *p = params;
 187     int mode = EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY;
 188     const char *mdname = EVP_MD_get0_name(md);
 189 #ifdef CHARSET_EBCDIC
 190     static const char derived_secret_label[] = { 0x64, 0x65, 0x72, 0x69, 0x76, 0x65, 0x64, 0x00 };
 191 #else
 192     static const char derived_secret_label[] = "derived";
 193 #endif
 194     unsigned char preextractsec[EVP_MAX_MD_SIZE];
 195
 196     kdf = EVP_KDF_fetch(s->ctx->libctx, OSSL_KDF_NAME_HKDF, s->ctx->propq);
 197     kctx = EVP_KDF_CTX_new(kdf);
 198     EVP_KDF_free(kdf);
 199     if (kctx == NULL) {
 200         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 201         return 0;
 202     }
 203
 204     mdleni = EVP_MD_get_size(md);
 205     /* Ensure cast to size_t is safe */
 206     if (!ossl_assert(mdleni >= 0)) {
 207         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 208         EVP_KDF_CTX_free(kctx);
 209         return 0;
 210     }
 211     mdlen = (size_t)mdleni;
 212
 213     if (insecret == NULL) {
 214         insecret = default_zeros;
 215         insecretlen = mdlen;
 216     }
 217     if (prevsecret == NULL) {
 218         prevsecret = default_zeros;
 219         prevsecretlen = 0;
 220     } else {
 221         EVP_MD_CTX *mctx = EVP_MD_CTX_new();
 222         unsigned char hash[EVP_MAX_MD_SIZE];
 223
 224         /* The pre-extract derive step uses a hash of no messages */
 225         if (mctx == NULL
 226                 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
 227                 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
 228             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 229             EVP_MD_CTX_free(mctx);
 230             EVP_KDF_CTX_free(kctx);
 231             return 0;
 232         }
 233         EVP_MD_CTX_free(mctx);
 234
 235         /* Generate the pre-extract secret */
 236         if (!tls13_hkdf_expand(s, md, prevsecret,
 237                                (unsigned char *)derived_secret_label,
 238                                sizeof(derived_secret_label) - 1, hash, mdlen,
 239                                preextractsec, mdlen, 1)) {
 240             /* SSLfatal() already called */
 241             EVP_KDF_CTX_free(kctx);
 242             return 0;
 243         }
 244
 245         prevsecret = preextractsec;
 246         prevsecretlen = mdlen;
 247     }
 248
 249     *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
 250     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
 251                                             (char *)mdname, 0);
 252     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
 253                                              (unsigned char *)insecret,
 254                                              insecretlen);
 255     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT,
 256                                              (unsigned char *)prevsecret,
 257                                              prevsecretlen);
 258     *p++ = OSSL_PARAM_construct_end();
 259
 260     ret = EVP_KDF_derive(kctx, outsecret, mdlen, params) <= 0;
 261
 262     if (ret != 0)
 263         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 264
 265     EVP_KDF_CTX_free(kctx);
 266     if (prevsecret == preextractsec)
 267         OPENSSL_cleanse(preextractsec, mdlen);
 268     return ret == 0;
 269 }
 270
 271 /*
 272  * Given an input secret |insecret| of length |insecretlen| generate the
 273  * handshake secret. This requires the early secret to already have been
 274  * generated. Returns 1 on success  0 on failure.
 275  */
 276 int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret,
 277                                 size_t insecretlen)
 278 {
 279     /* Calls SSLfatal() if required */
 280     return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
 281                                  insecret, insecretlen,
 282                                  (unsigned char *)&s->handshake_secret);
 283 }
 284
 285 /*
 286  * Given the handshake secret |prev| of length |prevlen| generate the master
 287  * secret and store its length in |*secret_size|. Returns 1 on success  0 on
 288  * failure.
 289  */
 290 int tls13_generate_master_secret(SSL *s, unsigned char *out,
 291                                  unsigned char *prev, size_t prevlen,
 292                                  size_t *secret_size)
 293 {
 294     const EVP_MD *md = ssl_handshake_md(s);
 295
 296     *secret_size = EVP_MD_get_size(md);
 297     /* Calls SSLfatal() if required */
 298     return tls13_generate_secret(s, md, prev, NULL, 0, out);
 299 }
 300
 301 /*
 302  * Generates the mac for the Finished message. Returns the length of the MAC or
 303  * 0 on error.
 304  */
 305 size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
 306                              unsigned char *out)
 307 {
 308     const char *mdname = EVP_MD_get0_name(ssl_handshake_md(s));
 309     unsigned char hash[EVP_MAX_MD_SIZE];
 310     unsigned char finsecret[EVP_MAX_MD_SIZE];
 311     unsigned char *key = NULL;
 312     unsigned int len = 0;
 313     size_t hashlen, ret = 0;
 314     OSSL_PARAM params[2], *p = params;
 315
 316     /* Safe to cast away const here since we're not "getting" any data */
 317     if (s->ctx->propq != NULL)
 318         *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_PROPERTIES,
 319                                                 (char *)s->ctx->propq,
 320                                                 0);
 321     *p = OSSL_PARAM_construct_end();
 322
 323     if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
 324         /* SSLfatal() already called */
 325         goto err;
 326     }
 327
 328     if (str == s->method->ssl3_enc->server_finished_label) {
 329         key = s->server_finished_secret;
 330     } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
 331         key = s->client_finished_secret;
 332     } else {
 333         if (!tls13_derive_finishedkey(s, ssl_handshake_md(s),
 334                                       s->client_app_traffic_secret,
 335                                       finsecret, hashlen))
 336             goto err;
 337         key = finsecret;
 338     }
 339
 340     if (!EVP_Q_mac(s->ctx->libctx, "HMAC", s->ctx->propq, mdname,
 341                    params, key, hashlen, hash, hashlen,
 342                    /* outsize as per sizeof(peer_finish_md) */
 343                    out, EVP_MAX_MD_SIZE * 2, &len)) {
 344         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 345         goto err;
 346     }
 347
 348     ret = len;
 349  err:
 350     OPENSSL_cleanse(finsecret, sizeof(finsecret));
 351     return ret;
 352 }
 353
 354 /*
 355  * There isn't really a key block in TLSv1.3, but we still need this function
 356  * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
 357  */
 358 int tls13_setup_key_block(SSL *s)
 359 {
 360     const EVP_CIPHER *c;
 361     const EVP_MD *hash;
 362
 363     s->session->cipher = s->s3.tmp.new_cipher;
 364     if (!ssl_cipher_get_evp(s->ctx, s->session, &c, &hash, NULL, NULL, NULL,
 365                             0)) {
 366         /* Error is already recorded */
 367         SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
 368         return 0;
 369     }
 370
 371     ssl_evp_cipher_free(s->s3.tmp.new_sym_enc);
 372     s->s3.tmp.new_sym_enc = c;
 373     ssl_evp_md_free(s->s3.tmp.new_hash);
 374     s->s3.tmp.new_hash = hash;
 375
 376     return 1;
 377 }
 378
 379 static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md,
 380                                     const EVP_CIPHER *ciph,
 381                                     const unsigned char *insecret,
 382                                     const unsigned char *hash,
 383                                     const unsigned char *label,
 384                                     size_t labellen, unsigned char *secret,
 385                                     unsigned char *key, unsigned char *iv,
 386                                     EVP_CIPHER_CTX *ciph_ctx)
 387 {
 388     size_t ivlen, keylen, taglen;
 389     int hashleni = EVP_MD_get_size(md);
 390     size_t hashlen;
 391
 392     /* Ensure cast to size_t is safe */
 393     if (!ossl_assert(hashleni >= 0)) {
 394         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
 395         return 0;
 396     }
 397     hashlen = (size_t)hashleni;
 398
 399     if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
 400                            secret, hashlen, 1)) {
 401         /* SSLfatal() already called */
 402         return 0;
 403     }
 404
 405     /* TODO(size_t): convert me */
 406     keylen = EVP_CIPHER_get_key_length(ciph);
 407     if (EVP_CIPHER_get_mode(ciph) == EVP_CIPH_CCM_MODE) {
 408         uint32_t algenc;
 409
 410         ivlen = EVP_CCM_TLS_IV_LEN;
 411         if (s->s3.tmp.new_cipher != NULL) {
 412             algenc = s->s3.tmp.new_cipher->algorithm_enc;
 413         } else if (s->session->cipher != NULL) {
 414             /* We've not selected a cipher yet - we must be doing early data */
 415             algenc = s->session->cipher->algorithm_enc;
 416         } else if (s->psksession != NULL && s->psksession->cipher != NULL) {
 417             /* We must be doing early data with out-of-band PSK */
 418             algenc = s->psksession->cipher->algorithm_enc;
 419         } else {
 420             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
 421             return 0;
 422         }
 423         if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
 424             taglen = EVP_CCM8_TLS_TAG_LEN;
 425          else
 426             taglen = EVP_CCM_TLS_TAG_LEN;
 427     } else {
 428         ivlen = EVP_CIPHER_get_iv_length(ciph);
 429         taglen = 0;
 430     }
 431
 432     if (!tls13_derive_key(s, md, secret, key, keylen)
 433             || !tls13_derive_iv(s, md, secret, iv, ivlen)) {
 434         /* SSLfatal() already called */
 435         return 0;
 436     }
 437
 438     if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0
 439         || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
 440         || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG,
 441                                                 taglen, NULL))
 442         || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
 443         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
 444         return 0;
 445     }
 446
 447     return 1;
 448 }
 449
 450 int tls13_change_cipher_state(SSL *s, int which)
 451 {
 452 #ifdef CHARSET_EBCDIC
 453   static const unsigned char client_early_traffic[]       = {0x63, 0x20, 0x65, 0x20,       /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 454   static const unsigned char client_handshake_traffic[]   = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 455   static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 456   static const unsigned char server_handshake_traffic[]   = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 457   static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 458   static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20,                    /* master*/  0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
 459   static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20,                  /* master*/  0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
 460   static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20,  /* master*/  0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
 461 #else
 462     static const unsigned char client_early_traffic[] = "c e traffic";
 463     static const unsigned char client_handshake_traffic[] = "c hs traffic";
 464     static const unsigned char client_application_traffic[] = "c ap traffic";
 465     static const unsigned char server_handshake_traffic[] = "s hs traffic";
 466     static const unsigned char server_application_traffic[] = "s ap traffic";
 467     static const unsigned char exporter_master_secret[] = "exp master";
 468     static const unsigned char resumption_master_secret[] = "res master";
 469     static const unsigned char early_exporter_master_secret[] = "e exp master";
 470 #endif
 471     unsigned char *iv;
 472     unsigned char key[EVP_MAX_KEY_LENGTH];
 473     unsigned char secret[EVP_MAX_MD_SIZE];
 474     unsigned char hashval[EVP_MAX_MD_SIZE];
 475     unsigned char *hash = hashval;
 476     unsigned char *insecret;
 477     unsigned char *finsecret = NULL;
 478     const char *log_label = NULL;
 479     EVP_CIPHER_CTX *ciph_ctx;
 480     size_t finsecretlen = 0;
 481     const unsigned char *label;
 482     size_t labellen, hashlen = 0;
 483     int ret = 0;
 484     const EVP_MD *md = NULL;
 485     const EVP_CIPHER *cipher = NULL;
 486 #if !defined(OPENSSL_NO_KTLS) && defined(OPENSSL_KTLS_TLS13)
 487     ktls_crypto_info_t crypto_info;
 488     BIO *bio;
 489 #endif
 490
 491     if (which & SSL3_CC_READ) {
 492         if (s->enc_read_ctx != NULL) {
 493             EVP_CIPHER_CTX_reset(s->enc_read_ctx);
 494         } else {
 495             s->enc_read_ctx = EVP_CIPHER_CTX_new();
 496             if (s->enc_read_ctx == NULL) {
 497                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
 498                 goto err;
 499             }
 500         }
 501         ciph_ctx = s->enc_read_ctx;
 502         iv = s->read_iv;
 503
 504         RECORD_LAYER_reset_read_sequence(&s->rlayer);
 505     } else {
 506         s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
 507         if (s->enc_write_ctx != NULL) {
 508             EVP_CIPHER_CTX_reset(s->enc_write_ctx);
 509         } else {
 510             s->enc_write_ctx = EVP_CIPHER_CTX_new();
 511             if (s->enc_write_ctx == NULL) {
 512                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
 513                 goto err;
 514             }
 515         }
 516         ciph_ctx = s->enc_write_ctx;
 517         iv = s->write_iv;
 518
 519         RECORD_LAYER_reset_write_sequence(&s->rlayer);
 520     }
 521
 522     if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
 523             || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
 524         if (which & SSL3_CC_EARLY) {
 525             EVP_MD_CTX *mdctx = NULL;
 526             long handlen;
 527             void *hdata;
 528             unsigned int hashlenui;
 529             const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
 530
 531             insecret = s->early_secret;
 532             label = client_early_traffic;
 533             labellen = sizeof(client_early_traffic) - 1;
 534             log_label = CLIENT_EARLY_LABEL;
 535
 536             handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
 537             if (handlen <= 0) {
 538                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_HANDSHAKE_LENGTH);
 539                 goto err;
 540             }
 541
 542             if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
 543                     && s->max_early_data > 0
 544                     && s->session->ext.max_early_data == 0) {
 545                 /*
 546                  * If we are attempting to send early data, and we've decided to
 547                  * actually do it but max_early_data in s->session is 0 then we
 548                  * must be using an external PSK.
 549                  */
 550                 if (!ossl_assert(s->psksession != NULL
 551                         && s->max_early_data ==
 552                            s->psksession->ext.max_early_data)) {
 553                     SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 554                     goto err;
 555                 }
 556                 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
 557             }
 558             if (sslcipher == NULL) {
 559                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_PSK);
 560                 goto err;
 561             }
 562
 563             /*
 564              * We need to calculate the handshake digest using the digest from
 565              * the session. We haven't yet selected our ciphersuite so we can't
 566              * use ssl_handshake_md().
 567              */
 568             mdctx = EVP_MD_CTX_new();
 569             if (mdctx == NULL) {
 570                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
 571                 goto err;
 572             }
 573
 574             /*
 575              * This ups the ref count on cipher so we better make sure we free
 576              * it again
 577              */
 578             if (!ssl_cipher_get_evp_cipher(s->ctx, sslcipher, &cipher)) {
 579                 /* Error is already recorded */
 580                 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
 581                 EVP_MD_CTX_free(mdctx);
 582                 goto err;
 583             }
 584
 585             md = ssl_md(s->ctx, sslcipher->algorithm2);
 586             if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
 587                     || !EVP_DigestUpdate(mdctx, hdata, handlen)
 588                     || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
 589                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 590                 EVP_MD_CTX_free(mdctx);
 591                 goto err;
 592             }
 593             hashlen = hashlenui;
 594             EVP_MD_CTX_free(mdctx);
 595
 596             if (!tls13_hkdf_expand(s, md, insecret,
 597                                    early_exporter_master_secret,
 598                                    sizeof(early_exporter_master_secret) - 1,
 599                                    hashval, hashlen,
 600                                    s->early_exporter_master_secret, hashlen,
 601                                    1)) {
 602                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 603                 goto err;
 604             }
 605
 606             if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
 607                                 s->early_exporter_master_secret, hashlen)) {
 608                 /* SSLfatal() already called */
 609                 goto err;
 610             }
 611         } else if (which & SSL3_CC_HANDSHAKE) {
 612             insecret = s->handshake_secret;
 613             finsecret = s->client_finished_secret;
 614             finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
 615             label = client_handshake_traffic;
 616             labellen = sizeof(client_handshake_traffic) - 1;
 617             log_label = CLIENT_HANDSHAKE_LABEL;
 618             /*
 619              * The handshake hash used for the server read/client write handshake
 620              * traffic secret is the same as the hash for the server
 621              * write/client read handshake traffic secret. However, if we
 622              * processed early data then we delay changing the server
 623              * read/client write cipher state until later, and the handshake
 624              * hashes have moved on. Therefore we use the value saved earlier
 625              * when we did the server write/client read change cipher state.
 626              */
 627             hash = s->handshake_traffic_hash;
 628         } else {
 629             insecret = s->master_secret;
 630             label = client_application_traffic;
 631             labellen = sizeof(client_application_traffic) - 1;
 632             log_label = CLIENT_APPLICATION_LABEL;
 633             /*
 634              * For this we only use the handshake hashes up until the server
 635              * Finished hash. We do not include the client's Finished, which is
 636              * what ssl_handshake_hash() would give us. Instead we use the
 637              * previously saved value.
 638              */
 639             hash = s->server_finished_hash;
 640         }
 641     } else {
 642         /* Early data never applies to client-read/server-write */
 643         if (which & SSL3_CC_HANDSHAKE) {
 644             insecret = s->handshake_secret;
 645             finsecret = s->server_finished_secret;
 646             finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
 647             label = server_handshake_traffic;
 648             labellen = sizeof(server_handshake_traffic) - 1;
 649             log_label = SERVER_HANDSHAKE_LABEL;
 650         } else {
 651             insecret = s->master_secret;
 652             label = server_application_traffic;
 653             labellen = sizeof(server_application_traffic) - 1;
 654             log_label = SERVER_APPLICATION_LABEL;
 655         }
 656     }
 657
 658     if (!(which & SSL3_CC_EARLY)) {
 659         md = ssl_handshake_md(s);
 660         cipher = s->s3.tmp.new_sym_enc;
 661         if (!ssl3_digest_cached_records(s, 1)
 662                 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
 663             /* SSLfatal() already called */;
 664             goto err;
 665         }
 666     }
 667
 668     /*
 669      * Save the hash of handshakes up to now for use when we calculate the
 670      * client application traffic secret
 671      */
 672     if (label == server_application_traffic)
 673         memcpy(s->server_finished_hash, hashval, hashlen);
 674
 675     if (label == server_handshake_traffic)
 676         memcpy(s->handshake_traffic_hash, hashval, hashlen);
 677
 678     if (label == client_application_traffic) {
 679         /*
 680          * We also create the resumption master secret, but this time use the
 681          * hash for the whole handshake including the Client Finished
 682          */
 683         if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
 684                                resumption_master_secret,
 685                                sizeof(resumption_master_secret) - 1,
 686                                hashval, hashlen, s->resumption_master_secret,
 687                                hashlen, 1)) {
 688             /* SSLfatal() already called */
 689             goto err;
 690         }
 691     }
 692
 693     /* check whether cipher is known */
 694     if(!ossl_assert(cipher != NULL))
 695         goto err;
 696
 697     if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
 698                                   insecret, hash, label, labellen, secret, key,
 699                                   iv, ciph_ctx)) {
 700         /* SSLfatal() already called */
 701         goto err;
 702     }
 703
 704     if (label == server_application_traffic) {
 705         memcpy(s->server_app_traffic_secret, secret, hashlen);
 706         /* Now we create the exporter master secret */
 707         if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
 708                                exporter_master_secret,
 709                                sizeof(exporter_master_secret) - 1,
 710                                hash, hashlen, s->exporter_master_secret,
 711                                hashlen, 1)) {
 712             /* SSLfatal() already called */
 713             goto err;
 714         }
 715
 716         if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
 717                             hashlen)) {
 718             /* SSLfatal() already called */
 719             goto err;
 720         }
 721     } else if (label == client_application_traffic)
 722         memcpy(s->client_app_traffic_secret, secret, hashlen);
 723
 724     if (!ssl_log_secret(s, log_label, secret, hashlen)) {
 725         /* SSLfatal() already called */
 726         goto err;
 727     }
 728
 729     if (finsecret != NULL
 730             && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
 731                                          finsecret, finsecretlen)) {
 732         /* SSLfatal() already called */
 733         goto err;
 734     }
 735
 736     if (!s->server && label == client_early_traffic)
 737         s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
 738     else
 739         s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
 740 #ifndef OPENSSL_NO_KTLS
 741 # if defined(OPENSSL_KTLS_TLS13)
 742     if (!(which & SSL3_CC_WRITE)
 743             || !(which & SSL3_CC_APPLICATION)
 744             || (s->options & SSL_OP_ENABLE_KTLS) == 0)
 745         goto skip_ktls;
 746
 747     /* ktls supports only the maximum fragment size */
 748     if (ssl_get_max_send_fragment(s) != SSL3_RT_MAX_PLAIN_LENGTH)
 749         goto skip_ktls;
 750
 751     /* ktls does not support record padding */
 752     if (s->record_padding_cb != NULL)
 753         goto skip_ktls;
 754
 755     /* check that cipher is supported */
 756     if (!ktls_check_supported_cipher(s, cipher, ciph_ctx))
 757         goto skip_ktls;
 758
 759     bio = s->wbio;
 760
 761     if (!ossl_assert(bio != NULL)) {
 762         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 763         goto err;
 764     }
 765
 766     /* All future data will get encrypted by ktls. Flush the BIO or skip ktls */
 767     if (BIO_flush(bio) <= 0)
 768         goto skip_ktls;
 769
 770     /* configure kernel crypto structure */
 771     if (!ktls_configure_crypto(s, cipher, ciph_ctx,
 772                                RECORD_LAYER_get_write_sequence(&s->rlayer),
 773                                &crypto_info, NULL, iv, key, NULL, 0))
 774         goto skip_ktls;
 775
 776     /* ktls works with user provided buffers directly */
 777     if (BIO_set_ktls(bio, &crypto_info, which & SSL3_CC_WRITE))
 778         ssl3_release_write_buffer(s);
 779 skip_ktls:
 780 # endif
 781 #endif
 782     ret = 1;
 783  err:
 784     if ((which & SSL3_CC_EARLY) != 0) {
 785         /* We up-refed this so now we need to down ref */
 786         ssl_evp_cipher_free(cipher);
 787     }
 788     OPENSSL_cleanse(key, sizeof(key));
 789     OPENSSL_cleanse(secret, sizeof(secret));
 790     return ret;
 791 }
 792
 793 int tls13_update_key(SSL *s, int sending)
 794 {
 795 #ifdef CHARSET_EBCDIC
 796   static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00};
 797 #else
 798   static const unsigned char application_traffic[] = "traffic upd";
 799 #endif
 800     const EVP_MD *md = ssl_handshake_md(s);
 801     size_t hashlen = EVP_MD_get_size(md);
 802     unsigned char key[EVP_MAX_KEY_LENGTH];
 803     unsigned char *insecret, *iv;
 804     unsigned char secret[EVP_MAX_MD_SIZE];
 805     EVP_CIPHER_CTX *ciph_ctx;
 806     int ret = 0;
 807
 808     if (s->server == sending)
 809         insecret = s->server_app_traffic_secret;
 810     else
 811         insecret = s->client_app_traffic_secret;
 812
 813     if (sending) {
 814         s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
 815         iv = s->write_iv;
 816         ciph_ctx = s->enc_write_ctx;
 817         RECORD_LAYER_reset_write_sequence(&s->rlayer);
 818     } else {
 819         iv = s->read_iv;
 820         ciph_ctx = s->enc_read_ctx;
 821         RECORD_LAYER_reset_read_sequence(&s->rlayer);
 822     }
 823
 824     if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s),
 825                                   s->s3.tmp.new_sym_enc, insecret, NULL,
 826                                   application_traffic,
 827                                   sizeof(application_traffic) - 1, secret, key,
 828                                   iv, ciph_ctx)) {
 829         /* SSLfatal() already called */
 830         goto err;
 831     }
 832
 833     memcpy(insecret, secret, hashlen);
 834
 835     s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
 836     ret = 1;
 837  err:
 838     OPENSSL_cleanse(key, sizeof(key));
 839     OPENSSL_cleanse(secret, sizeof(secret));
 840     return ret;
 841 }
 842
 843 int tls13_alert_code(int code)
 844 {
 845     /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
 846     if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
 847         return code;
 848
 849     return tls1_alert_code(code);
 850 }
 851
 852 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
 853                                  const char *label, size_t llen,
 854                                  const unsigned char *context,
 855                                  size_t contextlen, int use_context)
 856 {
 857     unsigned char exportsecret[EVP_MAX_MD_SIZE];
 858 #ifdef CHARSET_EBCDIC
 859     static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
 860 #else
 861     static const unsigned char exporterlabel[] = "exporter";
 862 #endif
 863     unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
 864     const EVP_MD *md = ssl_handshake_md(s);
 865     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 866     unsigned int hashsize, datalen;
 867     int ret = 0;
 868
 869     if (ctx == NULL || !ossl_statem_export_allowed(s))
 870         goto err;
 871
 872     if (!use_context)
 873         contextlen = 0;
 874
 875     if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
 876             || EVP_DigestUpdate(ctx, context, contextlen) <= 0
 877             || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
 878             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
 879             || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
 880             || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
 881                                   (const unsigned char *)label, llen,
 882                                   data, datalen, exportsecret, hashsize, 0)
 883             || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
 884                                   sizeof(exporterlabel) - 1, hash, hashsize,
 885                                   out, olen, 0))
 886         goto err;
 887
 888     ret = 1;
 889  err:
 890     EVP_MD_CTX_free(ctx);
 891     return ret;
 892 }
 893
 894 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen,
 895                                        const char *label, size_t llen,
 896                                        const unsigned char *context,
 897                                        size_t contextlen)
 898 {
 899 #ifdef CHARSET_EBCDIC
 900   static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
 901 #else
 902   static const unsigned char exporterlabel[] = "exporter";
 903 #endif
 904     unsigned char exportsecret[EVP_MAX_MD_SIZE];
 905     unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
 906     const EVP_MD *md;
 907     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 908     unsigned int hashsize, datalen;
 909     int ret = 0;
 910     const SSL_CIPHER *sslcipher;
 911
 912     if (ctx == NULL || !ossl_statem_export_early_allowed(s))
 913         goto err;
 914
 915     if (!s->server && s->max_early_data > 0
 916             && s->session->ext.max_early_data == 0)
 917         sslcipher = SSL_SESSION_get0_cipher(s->psksession);
 918     else
 919         sslcipher = SSL_SESSION_get0_cipher(s->session);
 920
 921     md = ssl_md(s->ctx, sslcipher->algorithm2);
 922
 923     /*
 924      * Calculate the hash value and store it in |data|. The reason why
 925      * the empty string is used is that the definition of TLS-Exporter
 926      * is like so:
 927      *
 928      * TLS-Exporter(label, context_value, key_length) =
 929      *     HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
 930      *                       "exporter", Hash(context_value), key_length)
 931      *
 932      * Derive-Secret(Secret, Label, Messages) =
 933      *       HKDF-Expand-Label(Secret, Label,
 934      *                         Transcript-Hash(Messages), Hash.length)
 935      *
 936      * Here Transcript-Hash is the cipher suite hash algorithm.
 937      */
 938     if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
 939             || EVP_DigestUpdate(ctx, context, contextlen) <= 0
 940             || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
 941             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
 942             || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
 943             || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
 944                                   (const unsigned char *)label, llen,
 945                                   data, datalen, exportsecret, hashsize, 0)
 946             || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
 947                                   sizeof(exporterlabel) - 1, hash, hashsize,
 948                                   out, olen, 0))
 949         goto err;
 950
 951     ret = 1;
 952  err:
 953     EVP_MD_CTX_free(ctx);
 954     return ret;
 955 }