ssl/tls13_enc.c

   1 /*
   2  * Copyright 2016-2022 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  */
  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
  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  */
 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  */
 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
 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  */
 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  */
 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  */
 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
 251     *secret_size = EVP_MD_get_size(md);
 252     /* Calls SSLfatal() if required */
 253     return tls13_generate_secret(s, md, prev, NULL, 0, out);
 254 }
 255
 256 /*
 257  * Generates the mac for the Finished message. Returns the length of the MAC or
 258  * 0 on error.
 259  */
 260 size_t tls13_final_finish_mac(SSL_CONNECTION *s, const char *str, size_t slen,
 261                              unsigned char *out)
 262 {
 263     const EVP_MD *md = ssl_handshake_md(s);
 264     const char *mdname = EVP_MD_get0_name(md);
 265     unsigned char hash[EVP_MAX_MD_SIZE];
 266     unsigned char finsecret[EVP_MAX_MD_SIZE];
 267     unsigned char *key = NULL;
 268     size_t len = 0, hashlen;
 269     OSSL_PARAM params[2], *p = params;
 270     SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
 271
 272     if (md == NULL)
 273         return 0;
 274
 275     /* Safe to cast away const here since we're not "getting" any data */
 276     if (sctx->propq != NULL)
 277         *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_PROPERTIES,
 278                                                 (char *)sctx->propq,
 279                                                 0);
 280     *p = OSSL_PARAM_construct_end();
 281
 282     if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
 283         /* SSLfatal() already called */
 284         goto err;
 285     }
 286
 287     if (str == SSL_CONNECTION_GET_SSL(s)->method->ssl3_enc->server_finished_label) {
 288         key = s->server_finished_secret;
 289     } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
 290         key = s->client_finished_secret;
 291     } else {
 292         if (!tls13_derive_finishedkey(s, md,
 293                                       s->client_app_traffic_secret,
 294                                       finsecret, hashlen))
 295             goto err;
 296         key = finsecret;
 297     }
 298
 299     if (!EVP_Q_mac(sctx->libctx, "HMAC", sctx->propq, mdname,
 300                    params, key, hashlen, hash, hashlen,
 301                    /* outsize as per sizeof(peer_finish_md) */
 302                    out, EVP_MAX_MD_SIZE * 2, &len)) {
 303         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 304         goto err;
 305     }
 306
 307  err:
 308     OPENSSL_cleanse(finsecret, sizeof(finsecret));
 309     return len;
 310 }
 311
 312 /*
 313  * There isn't really a key block in TLSv1.3, but we still need this function
 314  * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
 315  */
 316 int tls13_setup_key_block(SSL_CONNECTION *s)
 317 {
 318     const EVP_CIPHER *c;
 319     const EVP_MD *hash;
 320
 321     s->session->cipher = s->s3.tmp.new_cipher;
 322     if (!ssl_cipher_get_evp(SSL_CONNECTION_GET_CTX(s), s->session, &c, &hash,
 323                             NULL, NULL, NULL, 0)) {
 324         /* Error is already recorded */
 325         SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
 326         return 0;
 327     }
 328
 329     ssl_evp_cipher_free(s->s3.tmp.new_sym_enc);
 330     s->s3.tmp.new_sym_enc = c;
 331     ssl_evp_md_free(s->s3.tmp.new_hash);
 332     s->s3.tmp.new_hash = hash;
 333
 334     return 1;
 335 }
 336
 337 static int derive_secret_key_and_iv(SSL_CONNECTION *s, int sending,
 338                                     const EVP_MD *md,
 339                                     const EVP_CIPHER *ciph,
 340                                     const unsigned char *insecret,
 341                                     const unsigned char *hash,
 342                                     const unsigned char *label,
 343                                     size_t labellen, unsigned char *secret,
 344                                     unsigned char *key, size_t *keylen,
 345                                     unsigned char *iv, size_t *ivlen,
 346                                     size_t *taglen)
 347 {
 348     int hashleni = EVP_MD_get_size(md);
 349     size_t hashlen;
 350     int mode;
 351
 352     /* Ensure cast to size_t is safe */
 353     if (!ossl_assert(hashleni >= 0)) {
 354         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
 355         return 0;
 356     }
 357     hashlen = (size_t)hashleni;
 358
 359     if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
 360                            secret, hashlen, 1)) {
 361         /* SSLfatal() already called */
 362         return 0;
 363     }
 364
 365     *keylen = EVP_CIPHER_get_key_length(ciph);
 366
 367     mode = EVP_CIPHER_get_mode(ciph);
 368     if (mode == EVP_CIPH_CCM_MODE) {
 369         uint32_t algenc;
 370
 371         *ivlen = EVP_CCM_TLS_IV_LEN;
 372         if (s->s3.tmp.new_cipher != NULL) {
 373             algenc = s->s3.tmp.new_cipher->algorithm_enc;
 374         } else if (s->session->cipher != NULL) {
 375             /* We've not selected a cipher yet - we must be doing early data */
 376             algenc = s->session->cipher->algorithm_enc;
 377         } else if (s->psksession != NULL && s->psksession->cipher != NULL) {
 378             /* We must be doing early data with out-of-band PSK */
 379             algenc = s->psksession->cipher->algorithm_enc;
 380         } else {
 381             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
 382             return 0;
 383         }
 384         if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
 385             *taglen = EVP_CCM8_TLS_TAG_LEN;
 386          else
 387             *taglen = EVP_CCM_TLS_TAG_LEN;
 388     } else {
 389         int iivlen;
 390
 391         if (mode == EVP_CIPH_GCM_MODE) {
 392             *taglen = EVP_GCM_TLS_TAG_LEN;
 393         } else {
 394             /* CHACHA20P-POLY1305 */
 395             *taglen = EVP_CHACHAPOLY_TLS_TAG_LEN;
 396         }
 397         iivlen = EVP_CIPHER_get_iv_length(ciph);
 398         if (iivlen < 0) {
 399             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
 400             return 0;
 401         }
 402         *ivlen = iivlen;
 403     }
 404
 405     if (!tls13_derive_key(s, md, secret, key, *keylen)
 406             || !tls13_derive_iv(s, md, secret, iv, *ivlen)) {
 407         /* SSLfatal() already called */
 408         return 0;
 409     }
 410
 411     return 1;
 412 }
 413
 414 int tls13_change_cipher_state(SSL_CONNECTION *s, int which)
 415 {
 416     /* ASCII: "c e traffic", in hex for EBCDIC compatibility */
 417     static const unsigned char client_early_traffic[] = "\x63\x20\x65\x20\x74\x72\x61\x66\x66\x69\x63";
 418     /* ASCII: "c hs traffic", in hex for EBCDIC compatibility */
 419     static const unsigned char client_handshake_traffic[] = "\x63\x20\x68\x73\x20\x74\x72\x61\x66\x66\x69\x63";
 420     /* ASCII: "c ap traffic", in hex for EBCDIC compatibility */
 421     static const unsigned char client_application_traffic[] = "\x63\x20\x61\x70\x20\x74\x72\x61\x66\x66\x69\x63";
 422     /* ASCII: "s hs traffic", in hex for EBCDIC compatibility */
 423     static const unsigned char server_handshake_traffic[] = "\x73\x20\x68\x73\x20\x74\x72\x61\x66\x66\x69\x63";
 424     /* ASCII: "s ap traffic", in hex for EBCDIC compatibility */
 425     static const unsigned char server_application_traffic[] = "\x73\x20\x61\x70\x20\x74\x72\x61\x66\x66\x69\x63";
 426     /* ASCII: "exp master", in hex for EBCDIC compatibility */
 427     static const unsigned char exporter_master_secret[] = "\x65\x78\x70\x20\x6D\x61\x73\x74\x65\x72";
 428     /* ASCII: "res master", in hex for EBCDIC compatibility */
 429     static const unsigned char resumption_master_secret[] = "\x72\x65\x73\x20\x6D\x61\x73\x74\x65\x72";
 430     /* ASCII: "e exp master", in hex for EBCDIC compatibility */
 431     static const unsigned char early_exporter_master_secret[] = "\x65\x20\x65\x78\x70\x20\x6D\x61\x73\x74\x65\x72";
 432     unsigned char iv[EVP_MAX_IV_LENGTH];
 433     unsigned char key[EVP_MAX_KEY_LENGTH];
 434     unsigned char secret[EVP_MAX_MD_SIZE];
 435     unsigned char hashval[EVP_MAX_MD_SIZE];
 436     unsigned char *hash = hashval;
 437     unsigned char *insecret;
 438     unsigned char *finsecret = NULL;
 439     const char *log_label = NULL;
 440     size_t finsecretlen = 0;
 441     const unsigned char *label;
 442     size_t labellen, hashlen = 0;
 443     int ret = 0;
 444     const EVP_MD *md = NULL;
 445     const EVP_CIPHER *cipher = NULL;
 446     SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
 447     size_t keylen, ivlen, taglen;
 448     int level;
 449     int direction = (which & SSL3_CC_READ) != 0 ? OSSL_RECORD_DIRECTION_READ
 450                                                 : OSSL_RECORD_DIRECTION_WRITE;
 451
 452     if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
 453             || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
 454         if (which & SSL3_CC_EARLY) {
 455             EVP_MD_CTX *mdctx = NULL;
 456             long handlen;
 457             void *hdata;
 458             unsigned int hashlenui;
 459             const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
 460
 461             insecret = s->early_secret;
 462             label = client_early_traffic;
 463             labellen = sizeof(client_early_traffic) - 1;
 464             log_label = CLIENT_EARLY_LABEL;
 465
 466             handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
 467             if (handlen <= 0) {
 468                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_HANDSHAKE_LENGTH);
 469                 goto err;
 470             }
 471
 472             if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
 473                     && s->max_early_data > 0
 474                     && s->session->ext.max_early_data == 0) {
 475                 /*
 476                  * If we are attempting to send early data, and we've decided to
 477                  * actually do it but max_early_data in s->session is 0 then we
 478                  * must be using an external PSK.
 479                  */
 480                 if (!ossl_assert(s->psksession != NULL
 481                         && s->max_early_data ==
 482                            s->psksession->ext.max_early_data)) {
 483                     SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 484                     goto err;
 485                 }
 486                 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
 487             }
 488             if (sslcipher == NULL) {
 489                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_PSK);
 490                 goto err;
 491             }
 492
 493             /*
 494              * We need to calculate the handshake digest using the digest from
 495              * the session. We haven't yet selected our ciphersuite so we can't
 496              * use ssl_handshake_md().
 497              */
 498             mdctx = EVP_MD_CTX_new();
 499             if (mdctx == NULL) {
 500                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
 501                 goto err;
 502             }
 503
 504             /*
 505              * This ups the ref count on cipher so we better make sure we free
 506              * it again
 507              */
 508             if (!ssl_cipher_get_evp_cipher(sctx, sslcipher, &cipher)) {
 509                 /* Error is already recorded */
 510                 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
 511                 EVP_MD_CTX_free(mdctx);
 512                 goto err;
 513             }
 514
 515             md = ssl_md(sctx, sslcipher->algorithm2);
 516             if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
 517                     || !EVP_DigestUpdate(mdctx, hdata, handlen)
 518                     || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
 519                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 520                 EVP_MD_CTX_free(mdctx);
 521                 goto err;
 522             }
 523             hashlen = hashlenui;
 524             EVP_MD_CTX_free(mdctx);
 525
 526             if (!tls13_hkdf_expand(s, md, insecret,
 527                                    early_exporter_master_secret,
 528                                    sizeof(early_exporter_master_secret) - 1,
 529                                    hashval, hashlen,
 530                                    s->early_exporter_master_secret, hashlen,
 531                                    1)) {
 532                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 533                 goto err;
 534             }
 535
 536             if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
 537                                 s->early_exporter_master_secret, hashlen)) {
 538                 /* SSLfatal() already called */
 539                 goto err;
 540             }
 541         } else if (which & SSL3_CC_HANDSHAKE) {
 542             insecret = s->handshake_secret;
 543             finsecret = s->client_finished_secret;
 544             finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
 545             label = client_handshake_traffic;
 546             labellen = sizeof(client_handshake_traffic) - 1;
 547             log_label = CLIENT_HANDSHAKE_LABEL;
 548             /*
 549              * The handshake hash used for the server read/client write handshake
 550              * traffic secret is the same as the hash for the server
 551              * write/client read handshake traffic secret. However, if we
 552              * processed early data then we delay changing the server
 553              * read/client write cipher state until later, and the handshake
 554              * hashes have moved on. Therefore we use the value saved earlier
 555              * when we did the server write/client read change cipher state.
 556              */
 557             hash = s->handshake_traffic_hash;
 558         } else {
 559             insecret = s->master_secret;
 560             label = client_application_traffic;
 561             labellen = sizeof(client_application_traffic) - 1;
 562             log_label = CLIENT_APPLICATION_LABEL;
 563             /*
 564              * For this we only use the handshake hashes up until the server
 565              * Finished hash. We do not include the client's Finished, which is
 566              * what ssl_handshake_hash() would give us. Instead we use the
 567              * previously saved value.
 568              */
 569             hash = s->server_finished_hash;
 570         }
 571     } else {
 572         /* Early data never applies to client-read/server-write */
 573         if (which & SSL3_CC_HANDSHAKE) {
 574             insecret = s->handshake_secret;
 575             finsecret = s->server_finished_secret;
 576             finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
 577             label = server_handshake_traffic;
 578             labellen = sizeof(server_handshake_traffic) - 1;
 579             log_label = SERVER_HANDSHAKE_LABEL;
 580         } else {
 581             insecret = s->master_secret;
 582             label = server_application_traffic;
 583             labellen = sizeof(server_application_traffic) - 1;
 584             log_label = SERVER_APPLICATION_LABEL;
 585         }
 586     }
 587
 588     if (!(which & SSL3_CC_EARLY)) {
 589         md = ssl_handshake_md(s);
 590         cipher = s->s3.tmp.new_sym_enc;
 591         if (!ssl3_digest_cached_records(s, 1)
 592                 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
 593             /* SSLfatal() already called */;
 594             goto err;
 595         }
 596     }
 597
 598     /*
 599      * Save the hash of handshakes up to now for use when we calculate the
 600      * client application traffic secret
 601      */
 602     if (label == server_application_traffic)
 603         memcpy(s->server_finished_hash, hashval, hashlen);
 604
 605     if (label == server_handshake_traffic)
 606         memcpy(s->handshake_traffic_hash, hashval, hashlen);
 607
 608     if (label == client_application_traffic) {
 609         /*
 610          * We also create the resumption master secret, but this time use the
 611          * hash for the whole handshake including the Client Finished
 612          */
 613         if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
 614                                resumption_master_secret,
 615                                sizeof(resumption_master_secret) - 1,
 616                                hashval, hashlen, s->resumption_master_secret,
 617                                hashlen, 1)) {
 618             /* SSLfatal() already called */
 619             goto err;
 620         }
 621     }
 622
 623     /* check whether cipher is known */
 624     if (!ossl_assert(cipher != NULL))
 625         goto err;
 626
 627     if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
 628                                   insecret, hash, label, labellen, secret, key,
 629                                   &keylen, iv, &ivlen, &taglen)) {
 630         /* SSLfatal() already called */
 631         goto err;
 632     }
 633
 634     if (label == server_application_traffic) {
 635         memcpy(s->server_app_traffic_secret, secret, hashlen);
 636         /* Now we create the exporter master secret */
 637         if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
 638                                exporter_master_secret,
 639                                sizeof(exporter_master_secret) - 1,
 640                                hash, hashlen, s->exporter_master_secret,
 641                                hashlen, 1)) {
 642             /* SSLfatal() already called */
 643             goto err;
 644         }
 645
 646         if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
 647                             hashlen)) {
 648             /* SSLfatal() already called */
 649             goto err;
 650         }
 651     } else if (label == client_application_traffic)
 652         memcpy(s->client_app_traffic_secret, secret, hashlen);
 653
 654     if (!ssl_log_secret(s, log_label, secret, hashlen)) {
 655         /* SSLfatal() already called */
 656         goto err;
 657     }
 658
 659     if (finsecret != NULL
 660             && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
 661                                          finsecret, finsecretlen)) {
 662         /* SSLfatal() already called */
 663         goto err;
 664     }
 665
 666     if ((which & SSL3_CC_WRITE) != 0) {
 667         if (!s->server && label == client_early_traffic)
 668             s->rlayer.wrlmethod->set_plain_alerts(s->rlayer.wrl, 1);
 669         else
 670             s->rlayer.wrlmethod->set_plain_alerts(s->rlayer.wrl, 0);
 671     }
 672
 673     level = (which & SSL3_CC_EARLY) != 0
 674             ? OSSL_RECORD_PROTECTION_LEVEL_EARLY
 675             : ((which &SSL3_CC_HANDSHAKE) != 0
 676                ? OSSL_RECORD_PROTECTION_LEVEL_HANDSHAKE
 677                : OSSL_RECORD_PROTECTION_LEVEL_APPLICATION);
 678
 679     if (!ssl_set_new_record_layer(s, s->version,
 680                                   direction,
 681                                   level, secret, hashlen, key, keylen, iv,
 682                                   ivlen, NULL, 0, cipher, taglen, NID_undef,
 683                                   NULL, NULL, md)) {
 684         /* SSLfatal already called */
 685         goto err;
 686     }
 687
 688     ret = 1;
 689  err:
 690     if ((which & SSL3_CC_EARLY) != 0) {
 691         /* We up-refed this so now we need to down ref */
 692         ssl_evp_cipher_free(cipher);
 693     }
 694     OPENSSL_cleanse(key, sizeof(key));
 695     OPENSSL_cleanse(secret, sizeof(secret));
 696     return ret;
 697 }
 698
 699 int tls13_update_key(SSL_CONNECTION *s, int sending)
 700 {
 701     /* ASCII: "traffic upd", in hex for EBCDIC compatibility */
 702     static const unsigned char application_traffic[] = "\x74\x72\x61\x66\x66\x69\x63\x20\x75\x70\x64";
 703     const EVP_MD *md = ssl_handshake_md(s);
 704     size_t hashlen;
 705     unsigned char key[EVP_MAX_KEY_LENGTH];
 706     unsigned char *insecret;
 707     unsigned char secret[EVP_MAX_MD_SIZE];
 708     char *log_label;
 709     size_t keylen, ivlen, taglen;
 710     int ret = 0, l;
 711     int direction = sending ? OSSL_RECORD_DIRECTION_WRITE
 712                             : OSSL_RECORD_DIRECTION_READ;
 713     unsigned char iv[EVP_MAX_IV_LENGTH];
 714
 715     if ((l = EVP_MD_get_size(md)) <= 0) {
 716         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 717         return 0;
 718     }
 719     hashlen = (size_t)l;
 720
 721     if (s->server == sending)
 722         insecret = s->server_app_traffic_secret;
 723     else
 724         insecret = s->client_app_traffic_secret;
 725
 726     if (!derive_secret_key_and_iv(s, sending, md,
 727                                   s->s3.tmp.new_sym_enc, insecret, NULL,
 728                                   application_traffic,
 729                                   sizeof(application_traffic) - 1, secret, key,
 730                                   &keylen, iv, &ivlen, &taglen)) {
 731         /* SSLfatal() already called */
 732         goto err;
 733     }
 734
 735     memcpy(insecret, secret, hashlen);
 736
 737     if (!ssl_set_new_record_layer(s, s->version,
 738                             direction,
 739                             OSSL_RECORD_PROTECTION_LEVEL_APPLICATION,
 740                             insecret, hashlen, key, keylen, iv, ivlen, NULL, 0,
 741                             s->s3.tmp.new_sym_enc, taglen, NID_undef, NULL,
 742                             NULL, md)) {
 743         /* SSLfatal already called */
 744         goto err;
 745     }
 746
 747     /* Call Key log on successful traffic secret update */
 748     log_label = s->server == sending ? SERVER_APPLICATION_N_LABEL : CLIENT_APPLICATION_N_LABEL;
 749     if (!ssl_log_secret(s, log_label, secret, hashlen)) {
 750         /* SSLfatal() already called */
 751         goto err;
 752     }
 753     ret = 1;
 754  err:
 755     OPENSSL_cleanse(key, sizeof(key));
 756     OPENSSL_cleanse(secret, sizeof(secret));
 757     return ret;
 758 }
 759
 760 int tls13_alert_code(int code)
 761 {
 762     /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
 763     if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
 764         return code;
 765
 766     return tls1_alert_code(code);
 767 }
 768
 769 int tls13_export_keying_material(SSL_CONNECTION *s,
 770                                  unsigned char *out, size_t olen,
 771                                  const char *label, size_t llen,
 772                                  const unsigned char *context,
 773                                  size_t contextlen, int use_context)
 774 {
 775     unsigned char exportsecret[EVP_MAX_MD_SIZE];
 776     /* ASCII: "exporter", in hex for EBCDIC compatibility */
 777     static const unsigned char exporterlabel[] = "\x65\x78\x70\x6F\x72\x74\x65\x72";
 778     unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
 779     const EVP_MD *md = ssl_handshake_md(s);
 780     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 781     unsigned int hashsize, datalen;
 782     int ret = 0;
 783
 784     if (ctx == NULL || md == NULL || !ossl_statem_export_allowed(s))
 785         goto err;
 786
 787     if (!use_context)
 788         contextlen = 0;
 789
 790     if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
 791             || EVP_DigestUpdate(ctx, context, contextlen) <= 0
 792             || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
 793             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
 794             || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
 795             || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
 796                                   (const unsigned char *)label, llen,
 797                                   data, datalen, exportsecret, hashsize, 0)
 798             || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
 799                                   sizeof(exporterlabel) - 1, hash, hashsize,
 800                                   out, olen, 0))
 801         goto err;
 802
 803     ret = 1;
 804  err:
 805     EVP_MD_CTX_free(ctx);
 806     return ret;
 807 }
 808
 809 int tls13_export_keying_material_early(SSL_CONNECTION *s,
 810                                        unsigned char *out, size_t olen,
 811                                        const char *label, size_t llen,
 812                                        const unsigned char *context,
 813                                        size_t contextlen)
 814 {
 815     /* ASCII: "exporter", in hex for EBCDIC compatibility */
 816     static const unsigned char exporterlabel[] = "\x65\x78\x70\x6F\x72\x74\x65\x72";
 817     unsigned char exportsecret[EVP_MAX_MD_SIZE];
 818     unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
 819     const EVP_MD *md;
 820     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 821     unsigned int hashsize, datalen;
 822     int ret = 0;
 823     const SSL_CIPHER *sslcipher;
 824
 825     if (ctx == NULL || !ossl_statem_export_early_allowed(s))
 826         goto err;
 827
 828     if (!s->server && s->max_early_data > 0
 829             && s->session->ext.max_early_data == 0)
 830         sslcipher = SSL_SESSION_get0_cipher(s->psksession);
 831     else
 832         sslcipher = SSL_SESSION_get0_cipher(s->session);
 833
 834     md = ssl_md(SSL_CONNECTION_GET_CTX(s), sslcipher->algorithm2);
 835
 836     /*
 837      * Calculate the hash value and store it in |data|. The reason why
 838      * the empty string is used is that the definition of TLS-Exporter
 839      * is like so:
 840      *
 841      * TLS-Exporter(label, context_value, key_length) =
 842      *     HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
 843      *                       "exporter", Hash(context_value), key_length)
 844      *
 845      * Derive-Secret(Secret, Label, Messages) =
 846      *       HKDF-Expand-Label(Secret, Label,
 847      *                         Transcript-Hash(Messages), Hash.length)
 848      *
 849      * Here Transcript-Hash is the cipher suite hash algorithm.
 850      */
 851     if (md == NULL
 852             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
 853             || EVP_DigestUpdate(ctx, context, contextlen) <= 0
 854             || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
 855             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
 856             || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
 857             || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
 858                                   (const unsigned char *)label, llen,
 859                                   data, datalen, exportsecret, hashsize, 0)
 860             || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
 861                                   sizeof(exporterlabel) - 1, hash, hashsize,
 862                                   out, olen, 0))
 863         goto err;
 864
 865     ret = 1;
 866  err:
 867     EVP_MD_CTX_free(ctx);
 868     return ret;
 869 }