ssl/tls13_enc.c

   1 /*
   2  * Copyright 2016-2020 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_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, SSL_F_TLS13_HKDF_EXPAND,
  68                      ERR_R_INTERNAL_ERROR);
  69         } else {
  70             /*
  71              * Probably we have been called from SSL_export_keying_material(),
  72              * or SSL_export_keying_material_early().
  73              */
  74             SSLerr(SSL_F_TLS13_HKDF_EXPAND, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL);
  75         }
  76         EVP_KDF_CTX_free(kctx);
  77         return 0;
  78     }
  79
  80     hashlen = EVP_MD_size(md);
  81
  82     if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0)
  83             || !WPACKET_put_bytes_u16(&pkt, outlen)
  84             || !WPACKET_start_sub_packet_u8(&pkt)
  85             || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1)
  86             || !WPACKET_memcpy(&pkt, label, labellen)
  87             || !WPACKET_close(&pkt)
  88             || !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen)
  89             || !WPACKET_get_total_written(&pkt, &hkdflabellen)
  90             || !WPACKET_finish(&pkt)) {
  91         EVP_KDF_CTX_free(kctx);
  92         WPACKET_cleanup(&pkt);
  93         if (fatal)
  94             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
  95                      ERR_R_INTERNAL_ERROR);
  96         else
  97             SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
  98         return 0;
  99     }
 100
 101     *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
 102     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
 103                                             (char *)mdname, 0);
 104     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
 105                                              (unsigned char *)secret, hashlen);
 106     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_INFO,
 107                                              hkdflabel, hkdflabellen);
 108     *p++ = OSSL_PARAM_construct_end();
 109
 110     ret = EVP_KDF_CTX_set_params(kctx, params) <= 0
 111         || EVP_KDF_derive(kctx, out, outlen) <= 0;
 112
 113     EVP_KDF_CTX_free(kctx);
 114
 115     if (ret != 0) {
 116         if (fatal)
 117             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND,
 118                      ERR_R_INTERNAL_ERROR);
 119         else
 120             SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR);
 121     }
 122
 123     return ret == 0;
 124 }
 125
 126 /*
 127  * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on
 128  * success  0 on failure.
 129  */
 130 int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret,
 131                      unsigned char *key, size_t keylen)
 132 {
 133 #ifdef CHARSET_EBCDIC
 134   static const unsigned char keylabel[] ={ 0x6B, 0x65, 0x79, 0x00 };
 135 #else
 136   static const unsigned char keylabel[] = "key";
 137 #endif
 138
 139     return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1,
 140                              NULL, 0, key, keylen, 1);
 141 }
 142
 143 /*
 144  * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on
 145  * success  0 on failure.
 146  */
 147 int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret,
 148                     unsigned char *iv, size_t ivlen)
 149 {
 150 #ifdef CHARSET_EBCDIC
 151   static const unsigned char ivlabel[] = { 0x69, 0x76, 0x00 };
 152 #else
 153   static const unsigned char ivlabel[] = "iv";
 154 #endif
 155
 156     return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1,
 157                              NULL, 0, iv, ivlen, 1);
 158 }
 159
 160 int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
 161                              const unsigned char *secret,
 162                              unsigned char *fin, size_t finlen)
 163 {
 164 #ifdef CHARSET_EBCDIC
 165   static const unsigned char finishedlabel[] = { 0x66, 0x69, 0x6E, 0x69, 0x73, 0x68, 0x65, 0x64, 0x00 };
 166 #else
 167   static const unsigned char finishedlabel[] = "finished";
 168 #endif
 169
 170     return tls13_hkdf_expand(s, md, secret, finishedlabel,
 171                              sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1);
 172 }
 173
 174 /*
 175  * Given the previous secret |prevsecret| and a new input secret |insecret| of
 176  * length |insecretlen|, generate a new secret and store it in the location
 177  * pointed to by |outsecret|. Returns 1 on success  0 on failure.
 178  */
 179 int tls13_generate_secret(SSL *s, const EVP_MD *md,
 180                           const unsigned char *prevsecret,
 181                           const unsigned char *insecret,
 182                           size_t insecretlen,
 183                           unsigned char *outsecret)
 184 {
 185     size_t mdlen, prevsecretlen;
 186     int mdleni;
 187     int ret;
 188     EVP_KDF *kdf;
 189     EVP_KDF_CTX *kctx;
 190     OSSL_PARAM params[5], *p = params;
 191     int mode = EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY;
 192     const char *mdname = EVP_MD_name(md);
 193 #ifdef CHARSET_EBCDIC
 194     static const char derived_secret_label[] = { 0x64, 0x65, 0x72, 0x69, 0x76, 0x65, 0x64, 0x00 };
 195 #else
 196     static const char derived_secret_label[] = "derived";
 197 #endif
 198     unsigned char preextractsec[EVP_MAX_MD_SIZE];
 199
 200     kdf = EVP_KDF_fetch(s->ctx->libctx, OSSL_KDF_NAME_HKDF, s->ctx->propq);
 201     kctx = EVP_KDF_CTX_new(kdf);
 202     EVP_KDF_free(kdf);
 203     if (kctx == NULL) {
 204         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
 205                  ERR_R_INTERNAL_ERROR);
 206         return 0;
 207     }
 208
 209     mdleni = EVP_MD_size(md);
 210     /* Ensure cast to size_t is safe */
 211     if (!ossl_assert(mdleni >= 0)) {
 212         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
 213                  ERR_R_INTERNAL_ERROR);
 214         EVP_KDF_CTX_free(kctx);
 215         return 0;
 216     }
 217     mdlen = (size_t)mdleni;
 218
 219     if (insecret == NULL) {
 220         insecret = default_zeros;
 221         insecretlen = mdlen;
 222     }
 223     if (prevsecret == NULL) {
 224         prevsecret = default_zeros;
 225         prevsecretlen = 0;
 226     } else {
 227         EVP_MD_CTX *mctx = EVP_MD_CTX_new();
 228         unsigned char hash[EVP_MAX_MD_SIZE];
 229
 230         /* The pre-extract derive step uses a hash of no messages */
 231         if (mctx == NULL
 232                 || EVP_DigestInit_ex(mctx, md, NULL) <= 0
 233                 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) {
 234             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
 235                      ERR_R_INTERNAL_ERROR);
 236             EVP_MD_CTX_free(mctx);
 237             EVP_KDF_CTX_free(kctx);
 238             return 0;
 239         }
 240         EVP_MD_CTX_free(mctx);
 241
 242         /* Generate the pre-extract secret */
 243         if (!tls13_hkdf_expand(s, md, prevsecret,
 244                                (unsigned char *)derived_secret_label,
 245                                sizeof(derived_secret_label) - 1, hash, mdlen,
 246                                preextractsec, mdlen, 1)) {
 247             /* SSLfatal() already called */
 248             EVP_KDF_CTX_free(kctx);
 249             return 0;
 250         }
 251
 252         prevsecret = preextractsec;
 253         prevsecretlen = mdlen;
 254     }
 255
 256     *p++ = OSSL_PARAM_construct_int(OSSL_KDF_PARAM_MODE, &mode);
 257     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
 258                                             (char *)mdname, 0);
 259     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
 260                                              (unsigned char *)insecret,
 261                                              insecretlen);
 262     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT,
 263                                              (unsigned char *)prevsecret,
 264                                              prevsecretlen);
 265     *p++ = OSSL_PARAM_construct_end();
 266
 267     ret = EVP_KDF_CTX_set_params(kctx, params) <= 0
 268         || EVP_KDF_derive(kctx, outsecret, mdlen) <= 0;
 269
 270     if (ret != 0)
 271         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET,
 272                  ERR_R_INTERNAL_ERROR);
 273
 274     EVP_KDF_CTX_free(kctx);
 275     if (prevsecret == preextractsec)
 276         OPENSSL_cleanse(preextractsec, mdlen);
 277     return ret == 0;
 278 }
 279
 280 /*
 281  * Given an input secret |insecret| of length |insecretlen| generate the
 282  * handshake secret. This requires the early secret to already have been
 283  * generated. Returns 1 on success  0 on failure.
 284  */
 285 int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret,
 286                                 size_t insecretlen)
 287 {
 288     /* Calls SSLfatal() if required */
 289     return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret,
 290                                  insecret, insecretlen,
 291                                  (unsigned char *)&s->handshake_secret);
 292 }
 293
 294 /*
 295  * Given the handshake secret |prev| of length |prevlen| generate the master
 296  * secret and store its length in |*secret_size|. Returns 1 on success  0 on
 297  * failure.
 298  */
 299 int tls13_generate_master_secret(SSL *s, unsigned char *out,
 300                                  unsigned char *prev, size_t prevlen,
 301                                  size_t *secret_size)
 302 {
 303     const EVP_MD *md = ssl_handshake_md(s);
 304
 305     *secret_size = EVP_MD_size(md);
 306     /* Calls SSLfatal() if required */
 307     return tls13_generate_secret(s, md, prev, NULL, 0, out);
 308 }
 309
 310 /*
 311  * Generates the mac for the Finished message. Returns the length of the MAC or
 312  * 0 on error.
 313  */
 314 size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen,
 315                              unsigned char *out)
 316 {
 317     const char *mdname = EVP_MD_name(ssl_handshake_md(s));
 318     EVP_MAC *hmac = EVP_MAC_fetch(s->ctx->libctx, "HMAC", s->ctx->propq);
 319     unsigned char hash[EVP_MAX_MD_SIZE];
 320     unsigned char finsecret[EVP_MAX_MD_SIZE];
 321     size_t hashlen, ret = 0;
 322     EVP_MAC_CTX *ctx = NULL;
 323     OSSL_PARAM params[4], *p = params;
 324
 325     if (hmac == NULL) {
 326         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC,
 327                  ERR_R_INTERNAL_ERROR);
 328         goto err;
 329     }
 330
 331     /* Safe to cast away const here since we're not "getting" any data */
 332     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_DIGEST,
 333                                             (char *)mdname, 0);
 334     if (s->ctx->propq != NULL)
 335         *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ALG_PARAM_PROPERTIES,
 336                                                 (char *)s->ctx->propq,
 337                                                 0);
 338
 339     if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) {
 340         /* SSLfatal() already called */
 341         goto err;
 342     }
 343
 344     if (str == s->method->ssl3_enc->server_finished_label) {
 345         *p++ = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY,
 346                                                  s->server_finished_secret,
 347                                                  hashlen);
 348     } else if (SSL_IS_FIRST_HANDSHAKE(s)) {
 349         *p++ = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY,
 350                                                  s->client_finished_secret,
 351                                                  hashlen);
 352     } else {
 353         if (!tls13_derive_finishedkey(s, ssl_handshake_md(s),
 354                                       s->client_app_traffic_secret,
 355                                       finsecret, hashlen))
 356             goto err;
 357
 358         *p++ = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY, finsecret,
 359                                                  hashlen);
 360     }
 361     *p++ = OSSL_PARAM_construct_end();
 362
 363     ctx = EVP_MAC_CTX_new(hmac);
 364     if (ctx == NULL
 365             || !EVP_MAC_CTX_set_params(ctx, params)
 366             || !EVP_MAC_init(ctx)
 367             || !EVP_MAC_update(ctx, hash, hashlen)
 368                /* outsize as per sizeof(peer_finish_md) */
 369             || !EVP_MAC_final(ctx, out, &hashlen, EVP_MAX_MD_SIZE * 2)) {
 370         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC,
 371                  ERR_R_INTERNAL_ERROR);
 372         goto err;
 373     }
 374
 375     ret = hashlen;
 376  err:
 377     OPENSSL_cleanse(finsecret, sizeof(finsecret));
 378     EVP_MAC_CTX_free(ctx);
 379     EVP_MAC_free(hmac);
 380     return ret;
 381 }
 382
 383 /*
 384  * There isn't really a key block in TLSv1.3, but we still need this function
 385  * for initialising the cipher and hash. Returns 1 on success or 0 on failure.
 386  */
 387 int tls13_setup_key_block(SSL *s)
 388 {
 389     const EVP_CIPHER *c;
 390     const EVP_MD *hash;
 391
 392     s->session->cipher = s->s3.tmp.new_cipher;
 393     if (!ssl_cipher_get_evp(s->ctx, s->session, &c, &hash, NULL, NULL, NULL,
 394                             0)) {
 395         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK,
 396                  SSL_R_CIPHER_OR_HASH_UNAVAILABLE);
 397         return 0;
 398     }
 399
 400     ssl_evp_cipher_free(s->s3.tmp.new_sym_enc);
 401     s->s3.tmp.new_sym_enc = c;
 402     ssl_evp_md_free(s->s3.tmp.new_hash);
 403     s->s3.tmp.new_hash = hash;
 404
 405     return 1;
 406 }
 407
 408 static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md,
 409                                     const EVP_CIPHER *ciph,
 410                                     const unsigned char *insecret,
 411                                     const unsigned char *hash,
 412                                     const unsigned char *label,
 413                                     size_t labellen, unsigned char *secret,
 414                                     unsigned char *key, unsigned char *iv,
 415                                     EVP_CIPHER_CTX *ciph_ctx)
 416 {
 417     size_t ivlen, keylen, taglen;
 418     int hashleni = EVP_MD_size(md);
 419     size_t hashlen;
 420
 421     /* Ensure cast to size_t is safe */
 422     if (!ossl_assert(hashleni >= 0)) {
 423         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
 424                  ERR_R_EVP_LIB);
 425         return 0;
 426     }
 427     hashlen = (size_t)hashleni;
 428
 429     if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
 430                            secret, hashlen, 1)) {
 431         /* SSLfatal() already called */
 432         return 0;
 433     }
 434
 435     /* TODO(size_t): convert me */
 436     keylen = EVP_CIPHER_key_length(ciph);
 437     if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) {
 438         uint32_t algenc;
 439
 440         ivlen = EVP_CCM_TLS_IV_LEN;
 441         if (s->s3.tmp.new_cipher != NULL) {
 442             algenc = s->s3.tmp.new_cipher->algorithm_enc;
 443         } else if (s->session->cipher != NULL) {
 444             /* We've not selected a cipher yet - we must be doing early data */
 445             algenc = s->session->cipher->algorithm_enc;
 446         } else if (s->psksession != NULL && s->psksession->cipher != NULL) {
 447             /* We must be doing early data with out-of-band PSK */
 448             algenc = s->psksession->cipher->algorithm_enc;
 449         } else {
 450             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
 451                      ERR_R_EVP_LIB);
 452             return 0;
 453         }
 454         if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
 455             taglen = EVP_CCM8_TLS_TAG_LEN;
 456          else
 457             taglen = EVP_CCM_TLS_TAG_LEN;
 458     } else {
 459         ivlen = EVP_CIPHER_iv_length(ciph);
 460         taglen = 0;
 461     }
 462
 463     if (!tls13_derive_key(s, md, secret, key, keylen)
 464             || !tls13_derive_iv(s, md, secret, iv, ivlen)) {
 465         /* SSLfatal() already called */
 466         return 0;
 467     }
 468
 469     if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0
 470         || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
 471         || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG,
 472                                                 taglen, NULL))
 473         || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
 474         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV,
 475                  ERR_R_EVP_LIB);
 476         return 0;
 477     }
 478
 479     return 1;
 480 }
 481
 482 int tls13_change_cipher_state(SSL *s, int which)
 483 {
 484 #ifdef CHARSET_EBCDIC
 485   static const unsigned char client_early_traffic[]       = {0x63, 0x20, 0x65, 0x20,       /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 486   static const unsigned char client_handshake_traffic[]   = {0x63, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 487   static const unsigned char client_application_traffic[] = {0x63, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 488   static const unsigned char server_handshake_traffic[]   = {0x73, 0x20, 0x68, 0x73, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 489   static const unsigned char server_application_traffic[] = {0x73, 0x20, 0x61, 0x70, 0x20, /*traffic*/0x74, 0x72, 0x61, 0x66, 0x66, 0x69, 0x63, 0x00};
 490   static const unsigned char exporter_master_secret[] = {0x65, 0x78, 0x70, 0x20,                    /* master*/  0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
 491   static const unsigned char resumption_master_secret[] = {0x72, 0x65, 0x73, 0x20,                  /* master*/  0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
 492   static const unsigned char early_exporter_master_secret[] = {0x65, 0x20, 0x65, 0x78, 0x70, 0x20,  /* master*/  0x6D, 0x61, 0x73, 0x74, 0x65, 0x72, 0x00};
 493 #else
 494     static const unsigned char client_early_traffic[] = "c e traffic";
 495     static const unsigned char client_handshake_traffic[] = "c hs traffic";
 496     static const unsigned char client_application_traffic[] = "c ap traffic";
 497     static const unsigned char server_handshake_traffic[] = "s hs traffic";
 498     static const unsigned char server_application_traffic[] = "s ap traffic";
 499     static const unsigned char exporter_master_secret[] = "exp master";
 500     static const unsigned char resumption_master_secret[] = "res master";
 501     static const unsigned char early_exporter_master_secret[] = "e exp master";
 502 #endif
 503     unsigned char *iv;
 504     unsigned char key[EVP_MAX_KEY_LENGTH];
 505     unsigned char secret[EVP_MAX_MD_SIZE];
 506     unsigned char hashval[EVP_MAX_MD_SIZE];
 507     unsigned char *hash = hashval;
 508     unsigned char *insecret;
 509     unsigned char *finsecret = NULL;
 510     const char *log_label = NULL;
 511     EVP_CIPHER_CTX *ciph_ctx;
 512     size_t finsecretlen = 0;
 513     const unsigned char *label;
 514     size_t labellen, hashlen = 0;
 515     int ret = 0;
 516     const EVP_MD *md = NULL;
 517     const EVP_CIPHER *cipher = NULL;
 518 #if !defined(OPENSSL_NO_KTLS) && defined(OPENSSL_KTLS_TLS13)
 519 # ifndef __FreeBSD__
 520     struct tls_crypto_info_all crypto_info;
 521     BIO *bio;
 522 # endif
 523 #endif
 524
 525     if (which & SSL3_CC_READ) {
 526         if (s->enc_read_ctx != NULL) {
 527             EVP_CIPHER_CTX_reset(s->enc_read_ctx);
 528         } else {
 529             s->enc_read_ctx = EVP_CIPHER_CTX_new();
 530             if (s->enc_read_ctx == NULL) {
 531                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
 532                          SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
 533                 goto err;
 534             }
 535         }
 536         ciph_ctx = s->enc_read_ctx;
 537         iv = s->read_iv;
 538
 539         RECORD_LAYER_reset_read_sequence(&s->rlayer);
 540     } else {
 541         s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
 542         if (s->enc_write_ctx != NULL) {
 543             EVP_CIPHER_CTX_reset(s->enc_write_ctx);
 544         } else {
 545             s->enc_write_ctx = EVP_CIPHER_CTX_new();
 546             if (s->enc_write_ctx == NULL) {
 547                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
 548                          SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
 549                 goto err;
 550             }
 551         }
 552         ciph_ctx = s->enc_write_ctx;
 553         iv = s->write_iv;
 554
 555         RECORD_LAYER_reset_write_sequence(&s->rlayer);
 556     }
 557
 558     if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
 559             || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
 560         if (which & SSL3_CC_EARLY) {
 561             EVP_MD_CTX *mdctx = NULL;
 562             long handlen;
 563             void *hdata;
 564             unsigned int hashlenui;
 565             const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
 566
 567             insecret = s->early_secret;
 568             label = client_early_traffic;
 569             labellen = sizeof(client_early_traffic) - 1;
 570             log_label = CLIENT_EARLY_LABEL;
 571
 572             handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
 573             if (handlen <= 0) {
 574                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
 575                          SSL_F_TLS13_CHANGE_CIPHER_STATE,
 576                          SSL_R_BAD_HANDSHAKE_LENGTH);
 577                 goto err;
 578             }
 579
 580             if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
 581                     && s->max_early_data > 0
 582                     && s->session->ext.max_early_data == 0) {
 583                 /*
 584                  * If we are attempting to send early data, and we've decided to
 585                  * actually do it but max_early_data in s->session is 0 then we
 586                  * must be using an external PSK.
 587                  */
 588                 if (!ossl_assert(s->psksession != NULL
 589                         && s->max_early_data ==
 590                            s->psksession->ext.max_early_data)) {
 591                     SSLfatal(s, SSL_AD_INTERNAL_ERROR,
 592                              SSL_F_TLS13_CHANGE_CIPHER_STATE,
 593                              ERR_R_INTERNAL_ERROR);
 594                     goto err;
 595                 }
 596                 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
 597             }
 598             if (sslcipher == NULL) {
 599                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
 600                          SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK);
 601                 goto err;
 602             }
 603
 604             /*
 605              * We need to calculate the handshake digest using the digest from
 606              * the session. We haven't yet selected our ciphersuite so we can't
 607              * use ssl_handshake_md().
 608              */
 609             mdctx = EVP_MD_CTX_new();
 610             if (mdctx == NULL) {
 611                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
 612                          SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
 613                 goto err;
 614             }
 615
 616             /*
 617              * This ups the ref count on cipher so we better make sure we free
 618              * it again
 619              */
 620             if (!ssl_cipher_get_evp_cipher(s->ctx, sslcipher, &cipher)) {
 621                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
 622                          SSL_F_TLS13_CHANGE_CIPHER_STATE,
 623                          SSL_R_ALGORITHM_FETCH_FAILED);
 624                 EVP_MD_CTX_free(mdctx);
 625                 goto err;
 626             }
 627
 628             md = ssl_md(s->ctx, sslcipher->algorithm2);
 629             if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
 630                     || !EVP_DigestUpdate(mdctx, hdata, handlen)
 631                     || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
 632                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
 633                          SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 634                 EVP_MD_CTX_free(mdctx);
 635                 goto err;
 636             }
 637             hashlen = hashlenui;
 638             EVP_MD_CTX_free(mdctx);
 639
 640             if (!tls13_hkdf_expand(s, md, insecret,
 641                                    early_exporter_master_secret,
 642                                    sizeof(early_exporter_master_secret) - 1,
 643                                    hashval, hashlen,
 644                                    s->early_exporter_master_secret, hashlen,
 645                                    1)) {
 646                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
 647                          SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
 648                 goto err;
 649             }
 650
 651             if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
 652                                 s->early_exporter_master_secret, hashlen)) {
 653                 /* SSLfatal() already called */
 654                 goto err;
 655             }
 656         } else if (which & SSL3_CC_HANDSHAKE) {
 657             insecret = s->handshake_secret;
 658             finsecret = s->client_finished_secret;
 659             finsecretlen = EVP_MD_size(ssl_handshake_md(s));
 660             label = client_handshake_traffic;
 661             labellen = sizeof(client_handshake_traffic) - 1;
 662             log_label = CLIENT_HANDSHAKE_LABEL;
 663             /*
 664              * The handshake hash used for the server read/client write handshake
 665              * traffic secret is the same as the hash for the server
 666              * write/client read handshake traffic secret. However, if we
 667              * processed early data then we delay changing the server
 668              * read/client write cipher state until later, and the handshake
 669              * hashes have moved on. Therefore we use the value saved earlier
 670              * when we did the server write/client read change cipher state.
 671              */
 672             hash = s->handshake_traffic_hash;
 673         } else {
 674             insecret = s->master_secret;
 675             label = client_application_traffic;
 676             labellen = sizeof(client_application_traffic) - 1;
 677             log_label = CLIENT_APPLICATION_LABEL;
 678             /*
 679              * For this we only use the handshake hashes up until the server
 680              * Finished hash. We do not include the client's Finished, which is
 681              * what ssl_handshake_hash() would give us. Instead we use the
 682              * previously saved value.
 683              */
 684             hash = s->server_finished_hash;
 685         }
 686     } else {
 687         /* Early data never applies to client-read/server-write */
 688         if (which & SSL3_CC_HANDSHAKE) {
 689             insecret = s->handshake_secret;
 690             finsecret = s->server_finished_secret;
 691             finsecretlen = EVP_MD_size(ssl_handshake_md(s));
 692             label = server_handshake_traffic;
 693             labellen = sizeof(server_handshake_traffic) - 1;
 694             log_label = SERVER_HANDSHAKE_LABEL;
 695         } else {
 696             insecret = s->master_secret;
 697             label = server_application_traffic;
 698             labellen = sizeof(server_application_traffic) - 1;
 699             log_label = SERVER_APPLICATION_LABEL;
 700         }
 701     }
 702
 703     if (!(which & SSL3_CC_EARLY)) {
 704         md = ssl_handshake_md(s);
 705         cipher = s->s3.tmp.new_sym_enc;
 706         if (!ssl3_digest_cached_records(s, 1)
 707                 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
 708             /* SSLfatal() already called */;
 709             goto err;
 710         }
 711     }
 712
 713     /*
 714      * Save the hash of handshakes up to now for use when we calculate the
 715      * client application traffic secret
 716      */
 717     if (label == server_application_traffic)
 718         memcpy(s->server_finished_hash, hashval, hashlen);
 719
 720     if (label == server_handshake_traffic)
 721         memcpy(s->handshake_traffic_hash, hashval, hashlen);
 722
 723     if (label == client_application_traffic) {
 724         /*
 725          * We also create the resumption master secret, but this time use the
 726          * hash for the whole handshake including the Client Finished
 727          */
 728         if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
 729                                resumption_master_secret,
 730                                sizeof(resumption_master_secret) - 1,
 731                                hashval, hashlen, s->resumption_master_secret,
 732                                hashlen, 1)) {
 733             /* SSLfatal() already called */
 734             goto err;
 735         }
 736     }
 737
 738     /* check whether cipher is known */
 739     if(!ossl_assert(cipher != NULL))
 740         goto err;
 741
 742     if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
 743                                   insecret, hash, label, labellen, secret, key,
 744                                   iv, ciph_ctx)) {
 745         /* SSLfatal() already called */
 746         goto err;
 747     }
 748
 749     if (label == server_application_traffic) {
 750         memcpy(s->server_app_traffic_secret, secret, hashlen);
 751         /* Now we create the exporter master secret */
 752         if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
 753                                exporter_master_secret,
 754                                sizeof(exporter_master_secret) - 1,
 755                                hash, hashlen, s->exporter_master_secret,
 756                                hashlen, 1)) {
 757             /* SSLfatal() already called */
 758             goto err;
 759         }
 760
 761         if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
 762                             hashlen)) {
 763             /* SSLfatal() already called */
 764             goto err;
 765         }
 766     } else if (label == client_application_traffic)
 767         memcpy(s->client_app_traffic_secret, secret, hashlen);
 768
 769     if (!ssl_log_secret(s, log_label, secret, hashlen)) {
 770         /* SSLfatal() already called */
 771         goto err;
 772     }
 773
 774     if (finsecret != NULL
 775             && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
 776                                          finsecret, finsecretlen)) {
 777         /* SSLfatal() already called */
 778         goto err;
 779     }
 780
 781     if (!s->server && label == client_early_traffic)
 782         s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
 783     else
 784         s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
 785 #ifndef OPENSSL_NO_KTLS
 786 # if defined(OPENSSL_KTLS_TLS13)
 787 #  ifndef __FreeBSD__
 788     if (!(which & SSL3_CC_WRITE) || !(which & SSL3_CC_APPLICATION)
 789         || ((which & SSL3_CC_WRITE) && (s->mode & SSL_MODE_NO_KTLS_TX)))
 790         goto skip_ktls;
 791
 792     /* ktls supports only the maximum fragment size */
 793     if (ssl_get_max_send_fragment(s) != SSL3_RT_MAX_PLAIN_LENGTH)
 794         goto skip_ktls;
 795
 796     /* ktls does not support record padding */
 797     if (s->record_padding_cb != NULL)
 798         goto skip_ktls;
 799
 800     /* check that cipher is supported */
 801     if (!ktls_check_supported_cipher(cipher, ciph_ctx))
 802         goto skip_ktls;
 803
 804     bio = s->wbio;
 805
 806     if (!ossl_assert(bio != NULL)) {
 807         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_CHANGE_CIPHER_STATE,
 808                  ERR_R_INTERNAL_ERROR);
 809         goto err;
 810     }
 811
 812     /* All future data will get encrypted by ktls. Flush the BIO or skip ktls */
 813     if (BIO_flush(bio) <= 0)
 814         goto skip_ktls;
 815
 816     /* configure kernel crypto structure */
 817     if (!ktls_configure_crypto(cipher, s->version, ciph_ctx,
 818                                RECORD_LAYER_get_write_sequence(&s->rlayer),
 819                                &crypto_info, NULL, iv, key))
 820         goto skip_ktls;
 821
 822     /* ktls works with user provided buffers directly */
 823     if (BIO_set_ktls(bio, &crypto_info, which & SSL3_CC_WRITE))
 824         ssl3_release_write_buffer(s);
 825 #  endif
 826 skip_ktls:
 827 # endif
 828 #endif
 829     ret = 1;
 830  err:
 831     if ((which & SSL3_CC_EARLY) != 0) {
 832         /* We up-refed this so now we need to down ref */
 833         ssl_evp_cipher_free(cipher);
 834     }
 835     OPENSSL_cleanse(key, sizeof(key));
 836     OPENSSL_cleanse(secret, sizeof(secret));
 837     return ret;
 838 }
 839
 840 int tls13_update_key(SSL *s, int sending)
 841 {
 842 #ifdef CHARSET_EBCDIC
 843   static const unsigned char application_traffic[] = { 0x74, 0x72 ,0x61 ,0x66 ,0x66 ,0x69 ,0x63 ,0x20 ,0x75 ,0x70 ,0x64, 0x00};
 844 #else
 845   static const unsigned char application_traffic[] = "traffic upd";
 846 #endif
 847     const EVP_MD *md = ssl_handshake_md(s);
 848     size_t hashlen = EVP_MD_size(md);
 849     unsigned char key[EVP_MAX_KEY_LENGTH];
 850     unsigned char *insecret, *iv;
 851     unsigned char secret[EVP_MAX_MD_SIZE];
 852     EVP_CIPHER_CTX *ciph_ctx;
 853     int ret = 0;
 854
 855     if (s->server == sending)
 856         insecret = s->server_app_traffic_secret;
 857     else
 858         insecret = s->client_app_traffic_secret;
 859
 860     if (sending) {
 861         s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
 862         iv = s->write_iv;
 863         ciph_ctx = s->enc_write_ctx;
 864         RECORD_LAYER_reset_write_sequence(&s->rlayer);
 865     } else {
 866         iv = s->read_iv;
 867         ciph_ctx = s->enc_read_ctx;
 868         RECORD_LAYER_reset_read_sequence(&s->rlayer);
 869     }
 870
 871     if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s),
 872                                   s->s3.tmp.new_sym_enc, insecret, NULL,
 873                                   application_traffic,
 874                                   sizeof(application_traffic) - 1, secret, key,
 875                                   iv, ciph_ctx)) {
 876         /* SSLfatal() already called */
 877         goto err;
 878     }
 879
 880     memcpy(insecret, secret, hashlen);
 881
 882     s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
 883     ret = 1;
 884  err:
 885     OPENSSL_cleanse(key, sizeof(key));
 886     OPENSSL_cleanse(secret, sizeof(secret));
 887     return ret;
 888 }
 889
 890 int tls13_alert_code(int code)
 891 {
 892     /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
 893     if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
 894         return code;
 895
 896     return tls1_alert_code(code);
 897 }
 898
 899 int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
 900                                  const char *label, size_t llen,
 901                                  const unsigned char *context,
 902                                  size_t contextlen, int use_context)
 903 {
 904     unsigned char exportsecret[EVP_MAX_MD_SIZE];
 905 #ifdef CHARSET_EBCDIC
 906     static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
 907 #else
 908     static const unsigned char exporterlabel[] = "exporter";
 909 #endif
 910     unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
 911     const EVP_MD *md = ssl_handshake_md(s);
 912     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 913     unsigned int hashsize, datalen;
 914     int ret = 0;
 915
 916     if (ctx == NULL || !ossl_statem_export_allowed(s))
 917         goto err;
 918
 919     if (!use_context)
 920         contextlen = 0;
 921
 922     if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
 923             || EVP_DigestUpdate(ctx, context, contextlen) <= 0
 924             || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
 925             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
 926             || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
 927             || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
 928                                   (const unsigned char *)label, llen,
 929                                   data, datalen, exportsecret, hashsize, 0)
 930             || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
 931                                   sizeof(exporterlabel) - 1, hash, hashsize,
 932                                   out, olen, 0))
 933         goto err;
 934
 935     ret = 1;
 936  err:
 937     EVP_MD_CTX_free(ctx);
 938     return ret;
 939 }
 940
 941 int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen,
 942                                        const char *label, size_t llen,
 943                                        const unsigned char *context,
 944                                        size_t contextlen)
 945 {
 946 #ifdef CHARSET_EBCDIC
 947   static const unsigned char exporterlabel[] = {0x65, 0x78, 0x70, 0x6F, 0x72, 0x74, 0x65, 0x72, 0x00};
 948 #else
 949   static const unsigned char exporterlabel[] = "exporter";
 950 #endif
 951     unsigned char exportsecret[EVP_MAX_MD_SIZE];
 952     unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
 953     const EVP_MD *md;
 954     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 955     unsigned int hashsize, datalen;
 956     int ret = 0;
 957     const SSL_CIPHER *sslcipher;
 958
 959     if (ctx == NULL || !ossl_statem_export_early_allowed(s))
 960         goto err;
 961
 962     if (!s->server && s->max_early_data > 0
 963             && s->session->ext.max_early_data == 0)
 964         sslcipher = SSL_SESSION_get0_cipher(s->psksession);
 965     else
 966         sslcipher = SSL_SESSION_get0_cipher(s->session);
 967
 968     md = ssl_md(s->ctx, sslcipher->algorithm2);
 969
 970     /*
 971      * Calculate the hash value and store it in |data|. The reason why
 972      * the empty string is used is that the definition of TLS-Exporter
 973      * is like so:
 974      *
 975      * TLS-Exporter(label, context_value, key_length) =
 976      *     HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
 977      *                       "exporter", Hash(context_value), key_length)
 978      *
 979      * Derive-Secret(Secret, Label, Messages) =
 980      *       HKDF-Expand-Label(Secret, Label,
 981      *                         Transcript-Hash(Messages), Hash.length)
 982      *
 983      * Here Transcript-Hash is the cipher suite hash algorithm.
 984      */
 985     if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
 986             || EVP_DigestUpdate(ctx, context, contextlen) <= 0
 987             || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
 988             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
 989             || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
 990             || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
 991                                   (const unsigned char *)label, llen,
 992                                   data, datalen, exportsecret, hashsize, 0)
 993             || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
 994                                   sizeof(exporterlabel) - 1, hash, hashsize,
 995                                   out, olen, 0))
 996         goto err;
 997
 998     ret = 1;
 999  err:
1000     EVP_MD_CTX_free(ctx);
1001     return ret;
1002 }