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                                     EVP_CIPHER_CTX *ciph_ctx)
 348 {
 349     int hashleni = EVP_MD_get_size(md);
 350     size_t hashlen;
 351     int mode;
 352
 353     /* Ensure cast to size_t is safe */
 354     if (!ossl_assert(hashleni >= 0)) {
 355         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
 356         return 0;
 357     }
 358     hashlen = (size_t)hashleni;
 359
 360     if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
 361                            secret, hashlen, 1)) {
 362         /* SSLfatal() already called */
 363         return 0;
 364     }
 365
 366     *keylen = EVP_CIPHER_get_key_length(ciph);
 367
 368     mode = EVP_CIPHER_get_mode(ciph);
 369     if (mode == EVP_CIPH_CCM_MODE) {
 370         uint32_t algenc;
 371
 372         *ivlen = EVP_CCM_TLS_IV_LEN;
 373         if (s->s3.tmp.new_cipher != NULL) {
 374             algenc = s->s3.tmp.new_cipher->algorithm_enc;
 375         } else if (s->session->cipher != NULL) {
 376             /* We've not selected a cipher yet - we must be doing early data */
 377             algenc = s->session->cipher->algorithm_enc;
 378         } else if (s->psksession != NULL && s->psksession->cipher != NULL) {
 379             /* We must be doing early data with out-of-band PSK */
 380             algenc = s->psksession->cipher->algorithm_enc;
 381         } else {
 382             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
 383             return 0;
 384         }
 385         if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8))
 386             *taglen = EVP_CCM8_TLS_TAG_LEN;
 387          else
 388             *taglen = EVP_CCM_TLS_TAG_LEN;
 389     } else {
 390         int iivlen;
 391
 392         if (mode == EVP_CIPH_GCM_MODE) {
 393             *taglen = EVP_GCM_TLS_TAG_LEN;
 394         } else {
 395             /* CHACHA20P-POLY1305 */
 396             *taglen = EVP_CHACHAPOLY_TLS_TAG_LEN;
 397         }
 398         iivlen = EVP_CIPHER_get_iv_length(ciph);
 399         if (iivlen < 0) {
 400             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
 401             return 0;
 402         }
 403         *ivlen = iivlen;
 404     }
 405
 406     if (!tls13_derive_key(s, md, secret, key, *keylen)
 407             || !tls13_derive_iv(s, md, secret, iv, *ivlen)) {
 408         /* SSLfatal() already called */
 409         return 0;
 410     }
 411
 412     if (sending) {
 413         if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0
 414             || EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, *ivlen, NULL) <= 0
 415             || (mode == EVP_CIPH_CCM_MODE
 416                 && EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG, *taglen, NULL) <= 0)
 417             || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
 418             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
 419             return 0;
 420         }
 421     }
 422
 423     return 1;
 424 }
 425
 426 int tls13_change_cipher_state(SSL_CONNECTION *s, int which)
 427 {
 428     /* ASCII: "c e traffic", in hex for EBCDIC compatibility */
 429     static const unsigned char client_early_traffic[] = "\x63\x20\x65\x20\x74\x72\x61\x66\x66\x69\x63";
 430     /* ASCII: "c hs traffic", in hex for EBCDIC compatibility */
 431     static const unsigned char client_handshake_traffic[] = "\x63\x20\x68\x73\x20\x74\x72\x61\x66\x66\x69\x63";
 432     /* ASCII: "c ap traffic", in hex for EBCDIC compatibility */
 433     static const unsigned char client_application_traffic[] = "\x63\x20\x61\x70\x20\x74\x72\x61\x66\x66\x69\x63";
 434     /* ASCII: "s hs traffic", in hex for EBCDIC compatibility */
 435     static const unsigned char server_handshake_traffic[] = "\x73\x20\x68\x73\x20\x74\x72\x61\x66\x66\x69\x63";
 436     /* ASCII: "s ap traffic", in hex for EBCDIC compatibility */
 437     static const unsigned char server_application_traffic[] = "\x73\x20\x61\x70\x20\x74\x72\x61\x66\x66\x69\x63";
 438     /* ASCII: "exp master", in hex for EBCDIC compatibility */
 439     static const unsigned char exporter_master_secret[] = "\x65\x78\x70\x20\x6D\x61\x73\x74\x65\x72";
 440     /* ASCII: "res master", in hex for EBCDIC compatibility */
 441     static const unsigned char resumption_master_secret[] = "\x72\x65\x73\x20\x6D\x61\x73\x74\x65\x72";
 442     /* ASCII: "e exp master", in hex for EBCDIC compatibility */
 443     static const unsigned char early_exporter_master_secret[] = "\x65\x20\x65\x78\x70\x20\x6D\x61\x73\x74\x65\x72";
 444     unsigned char *iv;
 445     unsigned char key[EVP_MAX_KEY_LENGTH];
 446     unsigned char secret[EVP_MAX_MD_SIZE];
 447     unsigned char hashval[EVP_MAX_MD_SIZE];
 448     unsigned char *hash = hashval;
 449     unsigned char *insecret;
 450     unsigned char *finsecret = NULL;
 451     const char *log_label = NULL;
 452     EVP_CIPHER_CTX *ciph_ctx = NULL;
 453     size_t finsecretlen = 0;
 454     const unsigned char *label;
 455     size_t labellen, hashlen = 0;
 456     int ret = 0;
 457     const EVP_MD *md = NULL;
 458     const EVP_CIPHER *cipher = NULL;
 459     SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
 460     size_t keylen, ivlen, taglen;
 461     int level;
 462     int direction = (which & SSL3_CC_READ) != 0 ? OSSL_RECORD_DIRECTION_READ
 463                                                 : OSSL_RECORD_DIRECTION_WRITE;
 464 #if !defined(OPENSSL_NO_KTLS) && defined(OPENSSL_KTLS_TLS13)
 465     ktls_crypto_info_t crypto_info;
 466     void *rl_sequence;
 467     BIO *bio;
 468 #endif
 469
 470     if (which & SSL3_CC_READ) {
 471         iv = s->read_iv;
 472     } else {
 473         s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
 474         if (s->enc_write_ctx != NULL) {
 475             EVP_CIPHER_CTX_reset(s->enc_write_ctx);
 476         } else {
 477             s->enc_write_ctx = EVP_CIPHER_CTX_new();
 478             if (s->enc_write_ctx == NULL) {
 479                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
 480                 goto err;
 481             }
 482         }
 483         ciph_ctx = s->enc_write_ctx;
 484         iv = s->write_iv;
 485
 486         RECORD_LAYER_reset_write_sequence(&s->rlayer);
 487     }
 488
 489     if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
 490             || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
 491         if (which & SSL3_CC_EARLY) {
 492             EVP_MD_CTX *mdctx = NULL;
 493             long handlen;
 494             void *hdata;
 495             unsigned int hashlenui;
 496             const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);
 497
 498             insecret = s->early_secret;
 499             label = client_early_traffic;
 500             labellen = sizeof(client_early_traffic) - 1;
 501             log_label = CLIENT_EARLY_LABEL;
 502
 503             handlen = BIO_get_mem_data(s->s3.handshake_buffer, &hdata);
 504             if (handlen <= 0) {
 505                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_HANDSHAKE_LENGTH);
 506                 goto err;
 507             }
 508
 509             if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
 510                     && s->max_early_data > 0
 511                     && s->session->ext.max_early_data == 0) {
 512                 /*
 513                  * If we are attempting to send early data, and we've decided to
 514                  * actually do it but max_early_data in s->session is 0 then we
 515                  * must be using an external PSK.
 516                  */
 517                 if (!ossl_assert(s->psksession != NULL
 518                         && s->max_early_data ==
 519                            s->psksession->ext.max_early_data)) {
 520                     SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 521                     goto err;
 522                 }
 523                 sslcipher = SSL_SESSION_get0_cipher(s->psksession);
 524             }
 525             if (sslcipher == NULL) {
 526                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_PSK);
 527                 goto err;
 528             }
 529
 530             /*
 531              * We need to calculate the handshake digest using the digest from
 532              * the session. We haven't yet selected our ciphersuite so we can't
 533              * use ssl_handshake_md().
 534              */
 535             mdctx = EVP_MD_CTX_new();
 536             if (mdctx == NULL) {
 537                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_MALLOC_FAILURE);
 538                 goto err;
 539             }
 540
 541             /*
 542              * This ups the ref count on cipher so we better make sure we free
 543              * it again
 544              */
 545             if (!ssl_cipher_get_evp_cipher(sctx, sslcipher, &cipher)) {
 546                 /* Error is already recorded */
 547                 SSLfatal_alert(s, SSL_AD_INTERNAL_ERROR);
 548                 EVP_MD_CTX_free(mdctx);
 549                 goto err;
 550             }
 551
 552             md = ssl_md(sctx, sslcipher->algorithm2);
 553             if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
 554                     || !EVP_DigestUpdate(mdctx, hdata, handlen)
 555                     || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
 556                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 557                 EVP_MD_CTX_free(mdctx);
 558                 goto err;
 559             }
 560             hashlen = hashlenui;
 561             EVP_MD_CTX_free(mdctx);
 562
 563             if (!tls13_hkdf_expand(s, md, insecret,
 564                                    early_exporter_master_secret,
 565                                    sizeof(early_exporter_master_secret) - 1,
 566                                    hashval, hashlen,
 567                                    s->early_exporter_master_secret, hashlen,
 568                                    1)) {
 569                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 570                 goto err;
 571             }
 572
 573             if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
 574                                 s->early_exporter_master_secret, hashlen)) {
 575                 /* SSLfatal() already called */
 576                 goto err;
 577             }
 578         } else if (which & SSL3_CC_HANDSHAKE) {
 579             insecret = s->handshake_secret;
 580             finsecret = s->client_finished_secret;
 581             finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
 582             label = client_handshake_traffic;
 583             labellen = sizeof(client_handshake_traffic) - 1;
 584             log_label = CLIENT_HANDSHAKE_LABEL;
 585             /*
 586              * The handshake hash used for the server read/client write handshake
 587              * traffic secret is the same as the hash for the server
 588              * write/client read handshake traffic secret. However, if we
 589              * processed early data then we delay changing the server
 590              * read/client write cipher state until later, and the handshake
 591              * hashes have moved on. Therefore we use the value saved earlier
 592              * when we did the server write/client read change cipher state.
 593              */
 594             hash = s->handshake_traffic_hash;
 595         } else {
 596             insecret = s->master_secret;
 597             label = client_application_traffic;
 598             labellen = sizeof(client_application_traffic) - 1;
 599             log_label = CLIENT_APPLICATION_LABEL;
 600             /*
 601              * For this we only use the handshake hashes up until the server
 602              * Finished hash. We do not include the client's Finished, which is
 603              * what ssl_handshake_hash() would give us. Instead we use the
 604              * previously saved value.
 605              */
 606             hash = s->server_finished_hash;
 607         }
 608     } else {
 609         /* Early data never applies to client-read/server-write */
 610         if (which & SSL3_CC_HANDSHAKE) {
 611             insecret = s->handshake_secret;
 612             finsecret = s->server_finished_secret;
 613             finsecretlen = EVP_MD_get_size(ssl_handshake_md(s));
 614             label = server_handshake_traffic;
 615             labellen = sizeof(server_handshake_traffic) - 1;
 616             log_label = SERVER_HANDSHAKE_LABEL;
 617         } else {
 618             insecret = s->master_secret;
 619             label = server_application_traffic;
 620             labellen = sizeof(server_application_traffic) - 1;
 621             log_label = SERVER_APPLICATION_LABEL;
 622         }
 623     }
 624
 625     if (!(which & SSL3_CC_EARLY)) {
 626         md = ssl_handshake_md(s);
 627         cipher = s->s3.tmp.new_sym_enc;
 628         if (!ssl3_digest_cached_records(s, 1)
 629                 || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
 630             /* SSLfatal() already called */;
 631             goto err;
 632         }
 633     }
 634
 635     /*
 636      * Save the hash of handshakes up to now for use when we calculate the
 637      * client application traffic secret
 638      */
 639     if (label == server_application_traffic)
 640         memcpy(s->server_finished_hash, hashval, hashlen);
 641
 642     if (label == server_handshake_traffic)
 643         memcpy(s->handshake_traffic_hash, hashval, hashlen);
 644
 645     if (label == client_application_traffic) {
 646         /*
 647          * We also create the resumption master secret, but this time use the
 648          * hash for the whole handshake including the Client Finished
 649          */
 650         if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
 651                                resumption_master_secret,
 652                                sizeof(resumption_master_secret) - 1,
 653                                hashval, hashlen, s->resumption_master_secret,
 654                                hashlen, 1)) {
 655             /* SSLfatal() already called */
 656             goto err;
 657         }
 658     }
 659
 660     /* check whether cipher is known */
 661     if (!ossl_assert(cipher != NULL))
 662         goto err;
 663
 664     if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
 665                                   insecret, hash, label, labellen, secret, key,
 666                                   &keylen, iv, &ivlen, &taglen, ciph_ctx)) {
 667         /* SSLfatal() already called */
 668         goto err;
 669     }
 670
 671     if (label == server_application_traffic) {
 672         memcpy(s->server_app_traffic_secret, secret, hashlen);
 673         /* Now we create the exporter master secret */
 674         if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
 675                                exporter_master_secret,
 676                                sizeof(exporter_master_secret) - 1,
 677                                hash, hashlen, s->exporter_master_secret,
 678                                hashlen, 1)) {
 679             /* SSLfatal() already called */
 680             goto err;
 681         }
 682
 683         if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
 684                             hashlen)) {
 685             /* SSLfatal() already called */
 686             goto err;
 687         }
 688     } else if (label == client_application_traffic)
 689         memcpy(s->client_app_traffic_secret, secret, hashlen);
 690
 691     if (!ssl_log_secret(s, log_label, secret, hashlen)) {
 692         /* SSLfatal() already called */
 693         goto err;
 694     }
 695
 696     if (finsecret != NULL
 697             && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
 698                                          finsecret, finsecretlen)) {
 699         /* SSLfatal() already called */
 700         goto err;
 701     }
 702
 703     if (!s->server && label == client_early_traffic)
 704         s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
 705     else
 706         s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
 707
 708     level = (which & SSL3_CC_EARLY) != 0
 709             ? OSSL_RECORD_PROTECTION_LEVEL_EARLY
 710             : ((which &SSL3_CC_HANDSHAKE) != 0
 711                ? OSSL_RECORD_PROTECTION_LEVEL_HANDSHAKE
 712                : OSSL_RECORD_PROTECTION_LEVEL_APPLICATION);
 713
 714     if (!ssl_set_new_record_layer(s, s->version,
 715                                   direction,
 716                                   level, key, keylen, iv, ivlen, NULL, 0,
 717                                   cipher, taglen, NID_undef, NULL, NULL)) {
 718         /* SSLfatal already called */
 719         goto err;
 720     }
 721
 722     if ((which & SSL3_CC_READ) != 0) {
 723         /* TODO(RECLAYER): Remove me when write rlayer done */
 724         goto skip_ktls;
 725     }
 726
 727 #ifndef OPENSSL_NO_KTLS
 728 # if defined(OPENSSL_KTLS_TLS13)
 729     if (!(which & SSL3_CC_APPLICATION)
 730             || (s->options & SSL_OP_ENABLE_KTLS) == 0)
 731         goto skip_ktls;
 732
 733     /* ktls supports only the maximum fragment size */
 734     if (ssl_get_max_send_fragment(s) != SSL3_RT_MAX_PLAIN_LENGTH)
 735         goto skip_ktls;
 736
 737     /* ktls does not support record padding */
 738     if (s->record_padding_cb != NULL)
 739         goto skip_ktls;
 740
 741     /* check that cipher is supported */
 742     if (!ktls_check_supported_cipher(s, cipher, NULL, taglen))
 743         goto skip_ktls;
 744
 745     if (which & SSL3_CC_WRITE)
 746         bio = s->wbio;
 747     else
 748         bio = s->rbio;
 749
 750     if (!ossl_assert(bio != NULL)) {
 751         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 752         goto err;
 753     }
 754
 755     /* All future data will get encrypted by ktls. Flush the BIO or skip ktls */
 756     if (which & SSL3_CC_WRITE) {
 757         if (BIO_flush(bio) <= 0)
 758             goto skip_ktls;
 759     }
 760
 761     /* configure kernel crypto structure */
 762     /*
 763      * If we get here we are only doing the write side. The read side goes
 764      * through the new record layer code.
 765      */
 766     rl_sequence = RECORD_LAYER_get_write_sequence(&s->rlayer);
 767
 768     if (!ktls_configure_crypto(sctx->libctx, s->version, cipher, NULL,
 769                                rl_sequence, &crypto_info, which & SSL3_CC_WRITE,
 770                                iv, ivlen, key, keylen, NULL, 0))
 771         goto skip_ktls;
 772 # endif
 773 #endif
 774 skip_ktls:
 775     ret = 1;
 776  err:
 777     if ((which & SSL3_CC_EARLY) != 0) {
 778         /* We up-refed this so now we need to down ref */
 779         ssl_evp_cipher_free(cipher);
 780     }
 781     OPENSSL_cleanse(key, sizeof(key));
 782     OPENSSL_cleanse(secret, sizeof(secret));
 783     return ret;
 784 }
 785
 786 int tls13_update_key(SSL_CONNECTION *s, int sending)
 787 {
 788     /* ASCII: "traffic upd", in hex for EBCDIC compatibility */
 789     static const unsigned char application_traffic[] = "\x74\x72\x61\x66\x66\x69\x63\x20\x75\x70\x64";
 790     const EVP_MD *md = ssl_handshake_md(s);
 791     size_t hashlen;
 792     unsigned char key[EVP_MAX_KEY_LENGTH];
 793     unsigned char *insecret, *iv;
 794     unsigned char secret[EVP_MAX_MD_SIZE];
 795     EVP_CIPHER_CTX *ciph_ctx;
 796     size_t keylen, ivlen, taglen;
 797     int ret = 0, l;
 798     int direction = sending ? OSSL_RECORD_DIRECTION_WRITE
 799                             : OSSL_RECORD_DIRECTION_READ;
 800
 801     if ((l = EVP_MD_get_size(md)) <= 0) {
 802         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
 803         return 0;
 804     }
 805     hashlen = (size_t)l;
 806
 807     if (s->server == sending)
 808         insecret = s->server_app_traffic_secret;
 809     else
 810         insecret = s->client_app_traffic_secret;
 811
 812     if (sending) {
 813         s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
 814         iv = s->write_iv;
 815         ciph_ctx = s->enc_write_ctx;
 816         RECORD_LAYER_reset_write_sequence(&s->rlayer);
 817     } else {
 818         iv = s->read_iv;
 819         ciph_ctx = s->enc_read_ctx;
 820     }
 821
 822     if (!derive_secret_key_and_iv(s, sending, md,
 823                                   s->s3.tmp.new_sym_enc, insecret, NULL,
 824                                   application_traffic,
 825                                   sizeof(application_traffic) - 1, secret, key,
 826                                   &keylen, iv, &ivlen, &taglen, ciph_ctx)) {
 827         /* SSLfatal() already called */
 828         goto err;
 829     }
 830
 831     memcpy(insecret, secret, hashlen);
 832
 833     if (!ssl_set_new_record_layer(s, s->version,
 834                             direction,
 835                             OSSL_RECORD_PROTECTION_LEVEL_APPLICATION,
 836                             key, keylen, iv, ivlen, NULL, 0,
 837                             s->s3.tmp.new_sym_enc, taglen, NID_undef, NULL,
 838                             NULL)) {
 839         /* SSLfatal already called */
 840         goto err;
 841     }
 842
 843     s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
 844     ret = 1;
 845  err:
 846     OPENSSL_cleanse(key, sizeof(key));
 847     OPENSSL_cleanse(secret, sizeof(secret));
 848     return ret;
 849 }
 850
 851 int tls13_alert_code(int code)
 852 {
 853     /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */
 854     if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED)
 855         return code;
 856
 857     return tls1_alert_code(code);
 858 }
 859
 860 int tls13_export_keying_material(SSL_CONNECTION *s,
 861                                  unsigned char *out, size_t olen,
 862                                  const char *label, size_t llen,
 863                                  const unsigned char *context,
 864                                  size_t contextlen, int use_context)
 865 {
 866     unsigned char exportsecret[EVP_MAX_MD_SIZE];
 867     /* ASCII: "exporter", in hex for EBCDIC compatibility */
 868     static const unsigned char exporterlabel[] = "\x65\x78\x70\x6F\x72\x74\x65\x72";
 869     unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
 870     const EVP_MD *md = ssl_handshake_md(s);
 871     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 872     unsigned int hashsize, datalen;
 873     int ret = 0;
 874
 875     if (ctx == NULL || md == NULL || !ossl_statem_export_allowed(s))
 876         goto err;
 877
 878     if (!use_context)
 879         contextlen = 0;
 880
 881     if (EVP_DigestInit_ex(ctx, md, NULL) <= 0
 882             || EVP_DigestUpdate(ctx, context, contextlen) <= 0
 883             || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
 884             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
 885             || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
 886             || !tls13_hkdf_expand(s, md, s->exporter_master_secret,
 887                                   (const unsigned char *)label, llen,
 888                                   data, datalen, exportsecret, hashsize, 0)
 889             || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
 890                                   sizeof(exporterlabel) - 1, hash, hashsize,
 891                                   out, olen, 0))
 892         goto err;
 893
 894     ret = 1;
 895  err:
 896     EVP_MD_CTX_free(ctx);
 897     return ret;
 898 }
 899
 900 int tls13_export_keying_material_early(SSL_CONNECTION *s,
 901                                        unsigned char *out, size_t olen,
 902                                        const char *label, size_t llen,
 903                                        const unsigned char *context,
 904                                        size_t contextlen)
 905 {
 906     /* ASCII: "exporter", in hex for EBCDIC compatibility */
 907     static const unsigned char exporterlabel[] = "\x65\x78\x70\x6F\x72\x74\x65\x72";
 908     unsigned char exportsecret[EVP_MAX_MD_SIZE];
 909     unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE];
 910     const EVP_MD *md;
 911     EVP_MD_CTX *ctx = EVP_MD_CTX_new();
 912     unsigned int hashsize, datalen;
 913     int ret = 0;
 914     const SSL_CIPHER *sslcipher;
 915
 916     if (ctx == NULL || !ossl_statem_export_early_allowed(s))
 917         goto err;
 918
 919     if (!s->server && s->max_early_data > 0
 920             && s->session->ext.max_early_data == 0)
 921         sslcipher = SSL_SESSION_get0_cipher(s->psksession);
 922     else
 923         sslcipher = SSL_SESSION_get0_cipher(s->session);
 924
 925     md = ssl_md(SSL_CONNECTION_GET_CTX(s), sslcipher->algorithm2);
 926
 927     /*
 928      * Calculate the hash value and store it in |data|. The reason why
 929      * the empty string is used is that the definition of TLS-Exporter
 930      * is like so:
 931      *
 932      * TLS-Exporter(label, context_value, key_length) =
 933      *     HKDF-Expand-Label(Derive-Secret(Secret, label, ""),
 934      *                       "exporter", Hash(context_value), key_length)
 935      *
 936      * Derive-Secret(Secret, Label, Messages) =
 937      *       HKDF-Expand-Label(Secret, Label,
 938      *                         Transcript-Hash(Messages), Hash.length)
 939      *
 940      * Here Transcript-Hash is the cipher suite hash algorithm.
 941      */
 942     if (md == NULL
 943             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
 944             || EVP_DigestUpdate(ctx, context, contextlen) <= 0
 945             || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0
 946             || EVP_DigestInit_ex(ctx, md, NULL) <= 0
 947             || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0
 948             || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret,
 949                                   (const unsigned char *)label, llen,
 950                                   data, datalen, exportsecret, hashsize, 0)
 951             || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
 952                                   sizeof(exporterlabel) - 1, hash, hashsize,
 953                                   out, olen, 0))
 954         goto err;
 955
 956     ret = 1;
 957  err:
 958     EVP_MD_CTX_free(ctx);
 959     return ret;
 960 }