ssl/statem/statem_locl.h

   1 /*
   2  * Copyright 2015-2017 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (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 /*****************************************************************************
  11  *                                                                           *
  12  * The following definitions are PRIVATE to the state machine. They should   *
  13  * NOT be used outside of the state machine.                                 *
  14  *                                                                           *
  15  *****************************************************************************/
  16
  17 /* Max message length definitions */
  18
  19 /* The spec allows for a longer length than this, but we limit it */
  20 #define HELLO_VERIFY_REQUEST_MAX_LENGTH 258
  21 #define END_OF_EARLY_DATA_MAX_LENGTH    0
  22 #define SERVER_HELLO_MAX_LENGTH         20000
  23 #define HELLO_RETRY_REQUEST_MAX_LENGTH  20000
  24 #define ENCRYPTED_EXTENSIONS_MAX_LENGTH 20000
  25 #define SERVER_KEY_EXCH_MAX_LENGTH      102400
  26 #define SERVER_HELLO_DONE_MAX_LENGTH    0
  27 #define KEY_UPDATE_MAX_LENGTH           1
  28 #define CCS_MAX_LENGTH                  1
  29 /* Max should actually be 36 but we are generous */
  30 #define FINISHED_MAX_LENGTH             64
  31
  32 /* The maximum number of incoming KeyUpdate messages we will accept */
  33 #define MAX_KEY_UPDATE_MESSAGES     32
  34
  35 /* Dummy message type */
  36 #define SSL3_MT_DUMMY   -1
  37
  38 /* Message processing return codes */
  39 typedef enum {
  40     /* Something bad happened */
  41     MSG_PROCESS_ERROR,
  42     /* We've finished reading - swap to writing */
  43     MSG_PROCESS_FINISHED_READING,
  44     /*
  45      * We've completed the main processing of this message but there is some
  46      * post processing to be done.
  47      */
  48     MSG_PROCESS_CONTINUE_PROCESSING,
  49     /* We've finished this message - read the next message */
  50     MSG_PROCESS_CONTINUE_READING
  51 } MSG_PROCESS_RETURN;
  52
  53 /* Flush the write BIO */
  54 int statem_flush(SSL *s);
  55
  56 typedef int (*confunc_f) (SSL *s, WPACKET *pkt);
  57
  58 int check_in_list(SSL *s, uint16_t group_id, const uint16_t *groups,
  59                   size_t num_groups, int checkallow);
  60 int create_synthetic_message_hash(SSL *s);
  61 int parse_ca_names(SSL *s, PACKET *pkt);
  62 int construct_ca_names(SSL *s, WPACKET *pkt);
  63 size_t construct_key_exchange_tbs(SSL *s, unsigned char **ptbs,
  64                                   const void *param, size_t paramlen);
  65
  66 /*
  67  * TLS/DTLS client state machine functions
  68  */
  69 int ossl_statem_client_read_transition(SSL *s, int mt);
  70 WRITE_TRAN ossl_statem_client_write_transition(SSL *s);
  71 WORK_STATE ossl_statem_client_pre_work(SSL *s, WORK_STATE wst);
  72 WORK_STATE ossl_statem_client_post_work(SSL *s, WORK_STATE wst);
  73 int ossl_statem_client_construct_message(SSL *s, WPACKET *pkt,
  74                                          confunc_f *confunc, int *mt);
  75 size_t ossl_statem_client_max_message_size(SSL *s);
  76 MSG_PROCESS_RETURN ossl_statem_client_process_message(SSL *s, PACKET *pkt);
  77 WORK_STATE ossl_statem_client_post_process_message(SSL *s, WORK_STATE wst);
  78
  79 /*
  80  * TLS/DTLS server state machine functions
  81  */
  82 int ossl_statem_server_read_transition(SSL *s, int mt);
  83 WRITE_TRAN ossl_statem_server_write_transition(SSL *s);
  84 WORK_STATE ossl_statem_server_pre_work(SSL *s, WORK_STATE wst);
  85 WORK_STATE ossl_statem_server_post_work(SSL *s, WORK_STATE wst);
  86 int ossl_statem_server_construct_message(SSL *s, WPACKET *pkt,
  87                                          confunc_f *confunc,int *mt);
  88 size_t ossl_statem_server_max_message_size(SSL *s);
  89 MSG_PROCESS_RETURN ossl_statem_server_process_message(SSL *s, PACKET *pkt);
  90 WORK_STATE ossl_statem_server_post_process_message(SSL *s, WORK_STATE wst);
  91
  92 /* Functions for getting new message data */
  93 __owur int tls_get_message_header(SSL *s, int *mt);
  94 __owur int tls_get_message_body(SSL *s, size_t *len);
  95 __owur int dtls_get_message(SSL *s, int *mt, size_t *len);
  96
  97 /* Message construction and processing functions */
  98 __owur int tls_process_initial_server_flight(SSL *s);
  99 __owur MSG_PROCESS_RETURN tls_process_change_cipher_spec(SSL *s, PACKET *pkt);
 100 __owur MSG_PROCESS_RETURN tls_process_finished(SSL *s, PACKET *pkt);
 101 __owur int tls_construct_change_cipher_spec(SSL *s, WPACKET *pkt);
 102 __owur int dtls_construct_change_cipher_spec(SSL *s, WPACKET *pkt);
 103
 104 __owur int tls_construct_finished(SSL *s, WPACKET *pkt);
 105 __owur int tls_construct_key_update(SSL *s, WPACKET *pkt);
 106 __owur MSG_PROCESS_RETURN tls_process_key_update(SSL *s, PACKET *pkt);
 107 __owur WORK_STATE tls_finish_handshake(SSL *s, WORK_STATE wst, int clearbufs);
 108 __owur WORK_STATE dtls_wait_for_dry(SSL *s);
 109
 110 /* some client-only functions */
 111 __owur int tls_construct_client_hello(SSL *s, WPACKET *pkt);
 112 __owur MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt);
 113 __owur MSG_PROCESS_RETURN tls_process_certificate_request(SSL *s, PACKET *pkt);
 114 __owur MSG_PROCESS_RETURN tls_process_new_session_ticket(SSL *s, PACKET *pkt);
 115 __owur int tls_process_cert_status_body(SSL *s, PACKET *pkt);
 116 __owur MSG_PROCESS_RETURN tls_process_cert_status(SSL *s, PACKET *pkt);
 117 __owur MSG_PROCESS_RETURN tls_process_server_done(SSL *s, PACKET *pkt);
 118 __owur int tls_construct_cert_verify(SSL *s, WPACKET *pkt);
 119 __owur WORK_STATE tls_prepare_client_certificate(SSL *s, WORK_STATE wst);
 120 __owur int tls_construct_client_certificate(SSL *s, WPACKET *pkt);
 121 __owur int ssl_do_client_cert_cb(SSL *s, X509 **px509, EVP_PKEY **ppkey);
 122 __owur int tls_construct_client_key_exchange(SSL *s, WPACKET *pkt);
 123 __owur int tls_client_key_exchange_post_work(SSL *s);
 124 __owur int tls_construct_cert_status_body(SSL *s, WPACKET *pkt);
 125 __owur int tls_construct_cert_status(SSL *s, WPACKET *pkt);
 126 __owur MSG_PROCESS_RETURN tls_process_key_exchange(SSL *s, PACKET *pkt);
 127 __owur MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt);
 128 __owur int ssl3_check_cert_and_algorithm(SSL *s);
 129 #ifndef OPENSSL_NO_NEXTPROTONEG
 130 __owur int tls_construct_next_proto(SSL *s, WPACKET *pkt);
 131 #endif
 132 __owur MSG_PROCESS_RETURN tls_process_hello_req(SSL *s, PACKET *pkt);
 133 __owur MSG_PROCESS_RETURN dtls_process_hello_verify(SSL *s, PACKET *pkt);
 134 __owur int tls_construct_end_of_early_data(SSL *s, WPACKET *pkt);
 135
 136 /* some server-only functions */
 137 __owur MSG_PROCESS_RETURN tls_process_client_hello(SSL *s, PACKET *pkt);
 138 __owur WORK_STATE tls_post_process_client_hello(SSL *s, WORK_STATE wst);
 139 __owur int tls_construct_server_hello(SSL *s, WPACKET *pkt);
 140 __owur int dtls_construct_hello_verify_request(SSL *s, WPACKET *pkt);
 141 __owur int tls_construct_server_certificate(SSL *s, WPACKET *pkt);
 142 __owur int tls_construct_server_key_exchange(SSL *s, WPACKET *pkt);
 143 __owur int tls_construct_certificate_request(SSL *s, WPACKET *pkt);
 144 __owur int tls_construct_server_done(SSL *s, WPACKET *pkt);
 145 __owur MSG_PROCESS_RETURN tls_process_client_certificate(SSL *s, PACKET *pkt);
 146 __owur MSG_PROCESS_RETURN tls_process_client_key_exchange(SSL *s, PACKET *pkt);
 147 __owur WORK_STATE tls_post_process_client_key_exchange(SSL *s, WORK_STATE wst);
 148 __owur MSG_PROCESS_RETURN tls_process_cert_verify(SSL *s, PACKET *pkt);
 149 #ifndef OPENSSL_NO_NEXTPROTONEG
 150 __owur MSG_PROCESS_RETURN tls_process_next_proto(SSL *s, PACKET *pkt);
 151 #endif
 152 __owur int tls_construct_new_session_ticket(SSL *s, WPACKET *pkt);
 153 MSG_PROCESS_RETURN tls_process_end_of_early_data(SSL *s, PACKET *pkt);
 154
 155
 156 /* Extension processing */
 157
 158 typedef enum ext_return_en {
 159     EXT_RETURN_FAIL,
 160     EXT_RETURN_SENT,
 161     EXT_RETURN_NOT_SENT
 162 } EXT_RETURN;
 163
 164 __owur int extension_is_relevant(SSL *s, unsigned int extctx,
 165                                  unsigned int thisctx);
 166 __owur int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context,
 167                                   RAW_EXTENSION **res, size_t *len, int init);
 168 __owur int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context,
 169                                RAW_EXTENSION *exts,  X509 *x, size_t chainidx);
 170 __owur int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts,
 171                                     X509 *x, size_t chainidx, int fin);
 172 __owur int should_add_extension(SSL *s, unsigned int extctx,
 173                                 unsigned int thisctx, int max_version);
 174 __owur int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context,
 175                                     X509 *x, size_t chainidx);
 176
 177 __owur int tls_psk_do_binder(SSL *s, const EVP_MD *md,
 178                              const unsigned char *msgstart,
 179                              size_t binderoffset, const unsigned char *binderin,
 180                              unsigned char *binderout,
 181                              SSL_SESSION *sess, int sign, int external);
 182
 183 /* Server Extension processing */
 184 int tls_parse_ctos_renegotiate(SSL *s, PACKET *pkt, unsigned int context,
 185                                X509 *x, size_t chainidx);
 186 int tls_parse_ctos_server_name(SSL *s, PACKET *pkt, unsigned int context,
 187                                X509 *x, size_t chainidx);
 188 int tls_parse_ctos_maxfragmentlen(SSL *s, PACKET *pkt, unsigned int context,
 189                                   X509 *x, size_t chainidx);
 190 #ifndef OPENSSL_NO_SRP
 191 int tls_parse_ctos_srp(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 192                        size_t chainidx);
 193 #endif
 194 int tls_parse_ctos_early_data(SSL *s, PACKET *pkt, unsigned int context,
 195                               X509 *x, size_t chainidx);
 196 #ifndef OPENSSL_NO_EC
 197 int tls_parse_ctos_ec_pt_formats(SSL *s, PACKET *pkt, unsigned int context,
 198                                  X509 *x, size_t chainidx);
 199 int tls_parse_ctos_supported_groups(SSL *s, PACKET *pkt, unsigned int context,
 200                                     X509 *x, size_t chainidxl);
 201 #endif
 202 int tls_parse_ctos_session_ticket(SSL *s, PACKET *pkt, unsigned int context,
 203                                   X509 *x, size_t chainidx);
 204 int tls_parse_ctos_sig_algs(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 205                             size_t chainidx);
 206 #ifndef OPENSSL_NO_OCSP
 207 int tls_parse_ctos_status_request(SSL *s, PACKET *pkt, unsigned int context,
 208                                   X509 *x, size_t chainidx);
 209 #endif
 210 #ifndef OPENSSL_NO_NEXTPROTONEG
 211 int tls_parse_ctos_npn(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 212                        size_t chainidx);
 213 #endif
 214 int tls_parse_ctos_alpn(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 215                         size_t chainidx);
 216 #ifndef OPENSSL_NO_SRTP
 217 int tls_parse_ctos_use_srtp(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 218                             size_t chainidx);
 219 #endif
 220 int tls_parse_ctos_etm(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 221                        size_t chainidx);
 222 int tls_parse_ctos_key_share(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 223                              size_t chainidx);
 224 int tls_parse_ctos_ems(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 225                        size_t chainidx);
 226 int tls_parse_ctos_psk_kex_modes(SSL *s, PACKET *pkt, unsigned int context,
 227                                  X509 *x, size_t chainidx);
 228 int tls_parse_ctos_psk(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 229                        size_t chainidx);
 230
 231 EXT_RETURN tls_construct_stoc_renegotiate(SSL *s, WPACKET *pkt,
 232                                           unsigned int context, X509 *x,
 233                                           size_t chainidx);
 234 EXT_RETURN tls_construct_stoc_server_name(SSL *s, WPACKET *pkt,
 235                                           unsigned int context, X509 *x,
 236                                           size_t chainidx);
 237 EXT_RETURN tls_construct_stoc_early_data(SSL *s, WPACKET *pkt,
 238                                          unsigned int context, X509 *x,
 239                                          size_t chainidx);
 240 EXT_RETURN tls_construct_stoc_maxfragmentlen(SSL *s, WPACKET *pkt,
 241                                              unsigned int context, X509 *x,
 242                                              size_t chainidx);
 243 #ifndef OPENSSL_NO_EC
 244 EXT_RETURN tls_construct_stoc_ec_pt_formats(SSL *s, WPACKET *pkt,
 245                                             unsigned int context, X509 *x,
 246                                             size_t chainidx);
 247 #endif
 248 EXT_RETURN tls_construct_stoc_supported_groups(SSL *s, WPACKET *pkt,
 249                                                unsigned int context, X509 *x,
 250                                                size_t chainidx);
 251 EXT_RETURN tls_construct_stoc_session_ticket(SSL *s, WPACKET *pkt,
 252                                              unsigned int context, X509 *x,
 253                                              size_t chainidx);
 254 #ifndef OPENSSL_NO_OCSP
 255 EXT_RETURN tls_construct_stoc_status_request(SSL *s, WPACKET *pkt,
 256                                              unsigned int context, X509 *x,
 257                                              size_t chainidx);
 258 #endif
 259 #ifndef OPENSSL_NO_NEXTPROTONEG
 260 EXT_RETURN tls_construct_stoc_next_proto_neg(SSL *s, WPACKET *pkt,
 261                                              unsigned int context, X509 *x,
 262                                              size_t chainidx);
 263 #endif
 264 EXT_RETURN tls_construct_stoc_alpn(SSL *s, WPACKET *pkt, unsigned int context,
 265                                    X509 *x, size_t chainidx);
 266 #ifndef OPENSSL_NO_SRTP
 267 EXT_RETURN tls_construct_stoc_use_srtp(SSL *s, WPACKET *pkt, unsigned int context,
 268                                 X509 *x, size_t chainidx);
 269 #endif
 270 EXT_RETURN tls_construct_stoc_etm(SSL *s, WPACKET *pkt, unsigned int context,
 271                                   X509 *x, size_t chainidx);
 272 EXT_RETURN tls_construct_stoc_ems(SSL *s, WPACKET *pkt, unsigned int context,
 273                                   X509 *x, size_t chainidx);
 274 EXT_RETURN tls_construct_stoc_key_share(SSL *s, WPACKET *pkt,
 275                                         unsigned int context, X509 *x,
 276                                         size_t chainidx);
 277 /*
 278  * Not in public headers as this is not an official extension. Only used when
 279  * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set.
 280  */
 281 #define TLSEXT_TYPE_cryptopro_bug      0xfde8
 282 EXT_RETURN tls_construct_stoc_cryptopro_bug(SSL *s, WPACKET *pkt,
 283                                             unsigned int context, X509 *x,
 284                                             size_t chainidx);
 285 EXT_RETURN tls_construct_stoc_psk(SSL *s, WPACKET *pkt, unsigned int context,
 286                                   X509 *x, size_t chainidx);
 287
 288 /* Client Extension processing */
 289 EXT_RETURN tls_construct_ctos_renegotiate(SSL *s, WPACKET *pkt, unsigned int context,
 290                                    X509 *x, size_t chainidx);
 291 EXT_RETURN tls_construct_ctos_server_name(SSL *s, WPACKET *pkt, unsigned int context,
 292                                    X509 *x, size_t chainidx);
 293 EXT_RETURN tls_construct_ctos_maxfragmentlen(SSL *s, WPACKET *pkt, unsigned int context,
 294                                              X509 *x, size_t chainidx);
 295 #ifndef OPENSSL_NO_SRP
 296 EXT_RETURN tls_construct_ctos_srp(SSL *s, WPACKET *pkt, unsigned int context, X509 *x,
 297                            size_t chainidx);
 298 #endif
 299 #ifndef OPENSSL_NO_EC
 300 EXT_RETURN tls_construct_ctos_ec_pt_formats(SSL *s, WPACKET *pkt,
 301                                             unsigned int context, X509 *x,
 302                                             size_t chainidx);
 303 EXT_RETURN tls_construct_ctos_supported_groups(SSL *s, WPACKET *pkt,
 304                                                unsigned int context, X509 *x,
 305                                                size_t chainidx);
 306 #endif
 307 EXT_RETURN tls_construct_ctos_early_data(SSL *s, WPACKET *pkt,
 308                                          unsigned int context, X509 *x,
 309                                          size_t chainidx);
 310 EXT_RETURN tls_construct_ctos_session_ticket(SSL *s, WPACKET *pkt,
 311                                              unsigned int context, X509 *x,
 312                                              size_t chainidx);
 313 EXT_RETURN tls_construct_ctos_sig_algs(SSL *s, WPACKET *pkt,
 314                                        unsigned int context, X509 *x,
 315                                        size_t chainidx);
 316 #ifndef OPENSSL_NO_OCSP
 317 EXT_RETURN tls_construct_ctos_status_request(SSL *s, WPACKET *pkt,
 318                                              unsigned int context, X509 *x,
 319                                              size_t chainidx);
 320 #endif
 321 #ifndef OPENSSL_NO_NEXTPROTONEG
 322 EXT_RETURN tls_construct_ctos_npn(SSL *s, WPACKET *pkt, unsigned int context,
 323                                   X509 *x, size_t chainidx);
 324 #endif
 325 EXT_RETURN tls_construct_ctos_alpn(SSL *s, WPACKET *pkt, unsigned int context,
 326                                    X509 *x, size_t chainidx);
 327 #ifndef OPENSSL_NO_SRTP
 328 EXT_RETURN tls_construct_ctos_use_srtp(SSL *s, WPACKET *pkt, unsigned int context,
 329                                        X509 *x, size_t chainidx);
 330 #endif
 331 EXT_RETURN tls_construct_ctos_etm(SSL *s, WPACKET *pkt, unsigned int context,
 332                                   X509 *x, size_t chainidx);
 333 #ifndef OPENSSL_NO_CT
 334 EXT_RETURN tls_construct_ctos_sct(SSL *s, WPACKET *pkt, unsigned int context,
 335                                   X509 *x, size_t chainidx);
 336 #endif
 337 EXT_RETURN tls_construct_ctos_ems(SSL *s, WPACKET *pkt, unsigned int context,
 338                                   X509 *x, size_t chainidx);
 339 EXT_RETURN tls_construct_ctos_supported_versions(SSL *s, WPACKET *pkt,
 340                                                  unsigned int context, X509 *x,
 341                                                  size_t chainidx);
 342 EXT_RETURN tls_construct_ctos_key_share(SSL *s, WPACKET *pkt,
 343                                         unsigned int context, X509 *x,
 344                                         size_t chainidx);
 345 EXT_RETURN tls_construct_ctos_psk_kex_modes(SSL *s, WPACKET *pkt,
 346                                             unsigned int context, X509 *x,
 347                                             size_t chainidx);
 348 EXT_RETURN tls_construct_ctos_cookie(SSL *s, WPACKET *pkt, unsigned int context,
 349                                      X509 *x, size_t chainidx);
 350 EXT_RETURN tls_construct_ctos_padding(SSL *s, WPACKET *pkt,
 351                                       unsigned int context, X509 *x,
 352                                       size_t chainidx);
 353 EXT_RETURN tls_construct_ctos_psk(SSL *s, WPACKET *pkt, unsigned int context,
 354                                   X509 *x, size_t chainidx);
 355 int tls_parse_stoc_renegotiate(SSL *s, PACKET *pkt, unsigned int context,
 356                                X509 *x, size_t chainidx);
 357 int tls_parse_stoc_server_name(SSL *s, PACKET *pkt, unsigned int context,
 358                                X509 *x, size_t chainidx);
 359 int tls_parse_stoc_early_data(SSL *s, PACKET *pkt, unsigned int context,
 360                               X509 *x, size_t chainidx);
 361 int tls_parse_stoc_maxfragmentlen(SSL *s, PACKET *pkt, unsigned int context,
 362                                   X509 *x, size_t chainidx);
 363 #ifndef OPENSSL_NO_EC
 364 int tls_parse_stoc_ec_pt_formats(SSL *s, PACKET *pkt, unsigned int context,
 365                                  X509 *x, size_t chainidx);
 366 #endif
 367 int tls_parse_stoc_session_ticket(SSL *s, PACKET *pkt, unsigned int context,
 368                                   X509 *x, size_t chainidx);
 369 #ifndef OPENSSL_NO_OCSP
 370 int tls_parse_stoc_status_request(SSL *s, PACKET *pkt, unsigned int context,
 371                                   X509 *x, size_t chainidx);
 372 #endif
 373 #ifndef OPENSSL_NO_CT
 374 int tls_parse_stoc_sct(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 375                        size_t chainidx);
 376 #endif
 377 #ifndef OPENSSL_NO_NEXTPROTONEG
 378 int tls_parse_stoc_npn(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 379                        size_t chainidx);
 380 #endif
 381 int tls_parse_stoc_alpn(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 382                         size_t chainidx);
 383 #ifndef OPENSSL_NO_SRTP
 384 int tls_parse_stoc_use_srtp(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 385                             size_t chainidx);
 386 #endif
 387 int tls_parse_stoc_etm(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 388                        size_t chainidx);
 389 int tls_parse_stoc_ems(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 390                        size_t chainidx);
 391 int tls_parse_stoc_key_share(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 392                              size_t chainidx);
 393 int tls_parse_stoc_cookie(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 394                        size_t chainidx);
 395 int tls_parse_stoc_psk(SSL *s, PACKET *pkt, unsigned int context, X509 *x,
 396                        size_t chainidx);
 397
 398 int tls_handle_alpn(SSL *s);