/* * Copyright 2015-2022 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the Apache License 2.0 (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy * in the file LICENSE in the source distribution or at * https://www.openssl.org/source/license.html */ #include "internal/e_os.h" #if defined(__TANDEM) && defined(_SPT_MODEL_) # include # include /* timeval */ #endif #include "internal/cryptlib.h" #include #include "../ssl_local.h" #include "statem_local.h" #include /* * This file implements the SSL/TLS/DTLS state machines. * * There are two primary state machines: * * 1) Message flow state machine * 2) Handshake state machine * * The Message flow state machine controls the reading and sending of messages * including handling of non-blocking IO events, flushing of the underlying * write BIO, handling unexpected messages, etc. It is itself broken into two * separate sub-state machines which control reading and writing respectively. * * The Handshake state machine keeps track of the current SSL/TLS handshake * state. Transitions of the handshake state are the result of events that * occur within the Message flow state machine. * * Overall it looks like this: * * --------------------------------------------- ------------------- * | | | | * | Message flow state machine | | | * | | | | * | -------------------- -------------------- | Transition | Handshake state | * | | MSG_FLOW_READING | | MSG_FLOW_WRITING | | Event | machine | * | | sub-state | | sub-state | |----------->| | * | | machine for | | machine for | | | | * | | reading messages | | writing messages | | | | * | -------------------- -------------------- | | | * | | | | * --------------------------------------------- ------------------- * */ /* Sub state machine return values */ typedef enum { /* Something bad happened or NBIO */ SUB_STATE_ERROR, /* Sub state finished go to the next sub state */ SUB_STATE_FINISHED, /* Sub state finished and handshake was completed */ SUB_STATE_END_HANDSHAKE } SUB_STATE_RETURN; static int state_machine(SSL_CONNECTION *s, int server); static void init_read_state_machine(SSL_CONNECTION *s); static SUB_STATE_RETURN read_state_machine(SSL_CONNECTION *s); static void init_write_state_machine(SSL_CONNECTION *s); static SUB_STATE_RETURN write_state_machine(SSL_CONNECTION *s); OSSL_HANDSHAKE_STATE SSL_get_state(const SSL *ssl) { const SSL_CONNECTION *sc = SSL_CONNECTION_FROM_CONST_SSL(ssl); if (sc == NULL) return TLS_ST_BEFORE; return sc->statem.hand_state; } int SSL_in_init(const SSL *s) { const SSL_CONNECTION *sc = SSL_CONNECTION_FROM_CONST_SSL(s); if (sc == NULL) return 0; return sc->statem.in_init; } int SSL_is_init_finished(const SSL *s) { const SSL_CONNECTION *sc = SSL_CONNECTION_FROM_CONST_SSL(s); if (sc == NULL) return 0; return !(sc->statem.in_init) && (sc->statem.hand_state == TLS_ST_OK); } int SSL_in_before(const SSL *s) { const SSL_CONNECTION *sc = SSL_CONNECTION_FROM_CONST_SSL(s); if (sc == NULL) return 0; /* * Historically being "in before" meant before anything had happened. In the * current code though we remain in the "before" state for a while after we * have started the handshake process (e.g. as a server waiting for the * first message to arrive). There "in before" is taken to mean "in before" * and not started any handshake process yet. */ return (sc->statem.hand_state == TLS_ST_BEFORE) && (sc->statem.state == MSG_FLOW_UNINITED); } OSSL_HANDSHAKE_STATE ossl_statem_get_state(SSL_CONNECTION *s) { return s != NULL ? s->statem.hand_state : TLS_ST_BEFORE; } /* * Clear the state machine state and reset back to MSG_FLOW_UNINITED */ void ossl_statem_clear(SSL_CONNECTION *s) { s->statem.state = MSG_FLOW_UNINITED; s->statem.hand_state = TLS_ST_BEFORE; ossl_statem_set_in_init(s, 1); s->statem.no_cert_verify = 0; } /* * Set the state machine up ready for a renegotiation handshake */ void ossl_statem_set_renegotiate(SSL_CONNECTION *s) { ossl_statem_set_in_init(s, 1); s->statem.request_state = TLS_ST_SW_HELLO_REQ; } void ossl_statem_send_fatal(SSL_CONNECTION *s, int al) { /* We shouldn't call SSLfatal() twice. Once is enough */ if (s->statem.in_init && s->statem.state == MSG_FLOW_ERROR) return; ossl_statem_set_in_init(s, 1); s->statem.state = MSG_FLOW_ERROR; if (al != SSL_AD_NO_ALERT) ssl3_send_alert(s, SSL3_AL_FATAL, al); } /* * Error reporting building block that's used instead of ERR_set_error(). * In addition to what ERR_set_error() does, this puts the state machine * into an error state and sends an alert if appropriate. * This is a permanent error for the current connection. */ void ossl_statem_fatal(SSL_CONNECTION *s, int al, int reason, const char *fmt, ...) { va_list args; va_start(args, fmt); ERR_vset_error(ERR_LIB_SSL, reason, fmt, args); va_end(args); ossl_statem_send_fatal(s, al); } /* * This macro should only be called if we are already expecting to be in * a fatal error state. We verify that we are, and set it if not (this would * indicate a bug). */ #define check_fatal(s) \ do { \ if (!ossl_assert((s)->statem.in_init \ && (s)->statem.state == MSG_FLOW_ERROR)) \ SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_MISSING_FATAL); \ } while (0) /* * Discover whether the current connection is in the error state. * * Valid return values are: * 1: Yes * 0: No */ int ossl_statem_in_error(const SSL_CONNECTION *s) { if (s->statem.state == MSG_FLOW_ERROR) return 1; return 0; } void ossl_statem_set_in_init(SSL_CONNECTION *s, int init) { s->statem.in_init = init; if (s->rlayer.rrlmethod != NULL && s->rlayer.rrlmethod->set_in_init != NULL) s->rlayer.rrlmethod->set_in_init(s->rlayer.rrl, init); } int ossl_statem_get_in_handshake(SSL_CONNECTION *s) { return s->statem.in_handshake; } void ossl_statem_set_in_handshake(SSL_CONNECTION *s, int inhand) { if (inhand) s->statem.in_handshake++; else s->statem.in_handshake--; } /* Are we in a sensible state to skip over unreadable early data? */ int ossl_statem_skip_early_data(SSL_CONNECTION *s) { if (s->ext.early_data != SSL_EARLY_DATA_REJECTED) return 0; if (!s->server || s->statem.hand_state != TLS_ST_EARLY_DATA || s->hello_retry_request == SSL_HRR_COMPLETE) return 0; return 1; } /* * Called when we are in SSL_read*(), SSL_write*(), or SSL_accept() * /SSL_connect()/SSL_do_handshake(). Used to test whether we are in an early * data state and whether we should attempt to move the handshake on if so. * |sending| is 1 if we are attempting to send data (SSL_write*()), 0 if we are * attempting to read data (SSL_read*()), or -1 if we are in SSL_do_handshake() * or similar. */ void ossl_statem_check_finish_init(SSL_CONNECTION *s, int sending) { if (sending == -1) { if (s->statem.hand_state == TLS_ST_PENDING_EARLY_DATA_END || s->statem.hand_state == TLS_ST_EARLY_DATA) { ossl_statem_set_in_init(s, 1); if (s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY) { /* * SSL_connect() or SSL_do_handshake() has been called directly. * We don't allow any more writing of early data. */ s->early_data_state = SSL_EARLY_DATA_FINISHED_WRITING; } } } else if (!s->server) { if ((sending && (s->statem.hand_state == TLS_ST_PENDING_EARLY_DATA_END || s->statem.hand_state == TLS_ST_EARLY_DATA) && s->early_data_state != SSL_EARLY_DATA_WRITING) || (!sending && s->statem.hand_state == TLS_ST_EARLY_DATA)) { ossl_statem_set_in_init(s, 1); /* * SSL_write() has been called directly. We don't allow any more * writing of early data. */ if (sending && s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY) s->early_data_state = SSL_EARLY_DATA_FINISHED_WRITING; } } else { if (s->early_data_state == SSL_EARLY_DATA_FINISHED_READING && s->statem.hand_state == TLS_ST_EARLY_DATA) ossl_statem_set_in_init(s, 1); } } void ossl_statem_set_hello_verify_done(SSL_CONNECTION *s) { s->statem.state = MSG_FLOW_UNINITED; ossl_statem_set_in_init(s, 1); /* * This will get reset (briefly) back to TLS_ST_BEFORE when we enter * state_machine() because |state| is MSG_FLOW_UNINITED, but until then any * calls to SSL_in_before() will return false. Also calls to * SSL_state_string() and SSL_state_string_long() will return something * sensible. */ s->statem.hand_state = TLS_ST_SR_CLNT_HELLO; } int ossl_statem_connect(SSL *s) { SSL_CONNECTION *sc = SSL_CONNECTION_FROM_SSL(s); if (sc == NULL) return -1; return state_machine(sc, 0); } int ossl_statem_accept(SSL *s) { SSL_CONNECTION *sc = SSL_CONNECTION_FROM_SSL(s); if (sc == NULL) return -1; return state_machine(sc, 1); } typedef void (*info_cb) (const SSL *, int, int); static info_cb get_callback(SSL_CONNECTION *s) { SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s); if (s->info_callback != NULL) return s->info_callback; else if (sctx->info_callback != NULL) return sctx->info_callback; return NULL; } /* * The main message flow state machine. We start in the MSG_FLOW_UNINITED or * MSG_FLOW_FINISHED state and finish in MSG_FLOW_FINISHED. Valid states and * transitions are as follows: * * MSG_FLOW_UNINITED MSG_FLOW_FINISHED * | | * +-----------------------+ * v * MSG_FLOW_WRITING <---> MSG_FLOW_READING * | * V * MSG_FLOW_FINISHED * | * V * [SUCCESS] * * We may exit at any point due to an error or NBIO event. If an NBIO event * occurs then we restart at the point we left off when we are recalled. * MSG_FLOW_WRITING and MSG_FLOW_READING have sub-state machines associated with them. * * In addition to the above there is also the MSG_FLOW_ERROR state. We can move * into that state at any point in the event that an irrecoverable error occurs. * * Valid return values are: * 1: Success * <=0: NBIO or error */ static int state_machine(SSL_CONNECTION *s, int server) { BUF_MEM *buf = NULL; void (*cb) (const SSL *ssl, int type, int val) = NULL; OSSL_STATEM *st = &s->statem; int ret = -1; int ssret; SSL *ssl = SSL_CONNECTION_GET_SSL(s); SSL *ussl = SSL_CONNECTION_GET_USER_SSL(s); if (st->state == MSG_FLOW_ERROR) { /* Shouldn't have been called if we're already in the error state */ return -1; } ERR_clear_error(); clear_sys_error(); cb = get_callback(s); st->in_handshake++; if (!SSL_in_init(ssl) || SSL_in_before(ssl)) { /* * If we are stateless then we already called SSL_clear() - don't do * it again and clear the STATELESS flag itself. */ if ((s->s3.flags & TLS1_FLAGS_STATELESS) == 0 && !SSL_clear(ssl)) return -1; } #ifndef OPENSSL_NO_SCTP if (SSL_CONNECTION_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(ssl))) { /* * Notify SCTP BIO socket to enter handshake mode and prevent stream * identifier other than 0. */ BIO_ctrl(SSL_get_wbio(ssl), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE, st->in_handshake, NULL); } #endif /* Initialise state machine */ if (st->state == MSG_FLOW_UNINITED || st->state == MSG_FLOW_FINISHED) { if (st->state == MSG_FLOW_UNINITED) { st->hand_state = TLS_ST_BEFORE; st->request_state = TLS_ST_BEFORE; } s->server = server; if (cb != NULL) { if (SSL_IS_FIRST_HANDSHAKE(s) || !SSL_CONNECTION_IS_TLS13(s)) cb(ussl, SSL_CB_HANDSHAKE_START, 1); } /* * Fatal errors in this block don't send an alert because we have * failed to even initialise properly. Sending an alert is probably * doomed to failure. */ if (SSL_CONNECTION_IS_DTLS(s)) { if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00) && (server || (s->version & 0xff00) != (DTLS1_BAD_VER & 0xff00))) { SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR); goto end; } } else { if ((s->version >> 8) != SSL3_VERSION_MAJOR) { SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR); goto end; } } if (!ssl_security(s, SSL_SECOP_VERSION, 0, s->version, NULL)) { SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR); goto end; } if (s->init_buf == NULL) { if ((buf = BUF_MEM_new()) == NULL) { SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR); goto end; } if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) { SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR); goto end; } s->init_buf = buf; buf = NULL; } s->init_num = 0; /* * Should have been reset by tls_process_finished, too. */ s->s3.change_cipher_spec = 0; /* * Ok, we now need to push on a buffering BIO ...but not with * SCTP */ #ifndef OPENSSL_NO_SCTP if (!SSL_CONNECTION_IS_DTLS(s) || !BIO_dgram_is_sctp(SSL_get_wbio(ssl))) #endif if (!ssl_init_wbio_buffer(s)) { SSLfatal(s, SSL_AD_NO_ALERT, ERR_R_INTERNAL_ERROR); goto end; } if ((SSL_in_before(ssl)) || s->renegotiate) { if (!tls_setup_handshake(s)) { /* SSLfatal() already called */ goto end; } if (SSL_IS_FIRST_HANDSHAKE(s)) st->read_state_first_init = 1; } st->state = MSG_FLOW_WRITING; init_write_state_machine(s); } while (st->state != MSG_FLOW_FINISHED) { if (st->state == MSG_FLOW_READING) { ssret = read_state_machine(s); if (ssret == SUB_STATE_FINISHED) { st->state = MSG_FLOW_WRITING; init_write_state_machine(s); } else { /* NBIO or error */ goto end; } } else if (st->state == MSG_FLOW_WRITING) { ssret = write_state_machine(s); if (ssret == SUB_STATE_FINISHED) { st->state = MSG_FLOW_READING; init_read_state_machine(s); } else if (ssret == SUB_STATE_END_HANDSHAKE) { st->state = MSG_FLOW_FINISHED; } else { /* NBIO or error */ goto end; } } else { /* Error */ check_fatal(s); ERR_raise(ERR_LIB_SSL, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); goto end; } } ret = 1; end: st->in_handshake--; #ifndef OPENSSL_NO_SCTP if (SSL_CONNECTION_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(ssl))) { /* * Notify SCTP BIO socket to leave handshake mode and allow stream * identifier other than 0. */ BIO_ctrl(SSL_get_wbio(ssl), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE, st->in_handshake, NULL); } #endif BUF_MEM_free(buf); if (cb != NULL) { if (server) cb(ussl, SSL_CB_ACCEPT_EXIT, ret); else cb(ussl, SSL_CB_CONNECT_EXIT, ret); } return ret; } /* * Initialise the MSG_FLOW_READING sub-state machine */ static void init_read_state_machine(SSL_CONNECTION *s) { OSSL_STATEM *st = &s->statem; st->read_state = READ_STATE_HEADER; } static int grow_init_buf(SSL_CONNECTION *s, size_t size) { size_t msg_offset = (char *)s->init_msg - s->init_buf->data; if (!BUF_MEM_grow_clean(s->init_buf, (int)size)) return 0; if (size < msg_offset) return 0; s->init_msg = s->init_buf->data + msg_offset; return 1; } /* * This function implements the sub-state machine when the message flow is in * MSG_FLOW_READING. The valid sub-states and transitions are: * * READ_STATE_HEADER <--+<-------------+ * | | | * v | | * READ_STATE_BODY -----+-->READ_STATE_POST_PROCESS * | | * +----------------------------+ * v * [SUB_STATE_FINISHED] * * READ_STATE_HEADER has the responsibility for reading in the message header * and transitioning the state of the handshake state machine. * * READ_STATE_BODY reads in the rest of the message and then subsequently * processes it. * * READ_STATE_POST_PROCESS is an optional step that may occur if some post * processing activity performed on the message may block. * * Any of the above states could result in an NBIO event occurring in which case * control returns to the calling application. When this function is recalled we * will resume in the same state where we left off. */ static SUB_STATE_RETURN read_state_machine(SSL_CONNECTION *s) { OSSL_STATEM *st = &s->statem; int ret, mt; size_t len = 0; int (*transition) (SSL_CONNECTION *s, int mt); PACKET pkt; MSG_PROCESS_RETURN(*process_message) (SSL_CONNECTION *s, PACKET *pkt); WORK_STATE(*post_process_message) (SSL_CONNECTION *s, WORK_STATE wst); size_t (*max_message_size) (SSL_CONNECTION *s); void (*cb) (const SSL *ssl, int type, int val) = NULL; SSL *ssl = SSL_CONNECTION_GET_USER_SSL(s); cb = get_callback(s); if (s->server) { transition = ossl_statem_server_read_transition; process_message = ossl_statem_server_process_message; max_message_size = ossl_statem_server_max_message_size; post_process_message = ossl_statem_server_post_process_message; } else { transition = ossl_statem_client_read_transition; process_message = ossl_statem_client_process_message; max_message_size = ossl_statem_client_max_message_size; post_process_message = ossl_statem_client_post_process_message; } if (st->read_state_first_init) { s->first_packet = 1; st->read_state_first_init = 0; } while (1) { switch (st->read_state) { case READ_STATE_HEADER: /* Get the state the peer wants to move to */ if (SSL_CONNECTION_IS_DTLS(s)) { /* * In DTLS we get the whole message in one go - header and body */ ret = dtls_get_message(s, &mt); } else { ret = tls_get_message_header(s, &mt); } if (ret == 0) { /* Could be non-blocking IO */ return SUB_STATE_ERROR; } if (cb != NULL) { /* Notify callback of an impending state change */ if (s->server) cb(ssl, SSL_CB_ACCEPT_LOOP, 1); else cb(ssl, SSL_CB_CONNECT_LOOP, 1); } /* * Validate that we are allowed to move to the new state and move * to that state if so */ if (!transition(s, mt)) return SUB_STATE_ERROR; if (s->s3.tmp.message_size > max_message_size(s)) { SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_EXCESSIVE_MESSAGE_SIZE); return SUB_STATE_ERROR; } /* dtls_get_message already did this */ if (!SSL_CONNECTION_IS_DTLS(s) && s->s3.tmp.message_size > 0 && !grow_init_buf(s, s->s3.tmp.message_size + SSL3_HM_HEADER_LENGTH)) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_BUF_LIB); return SUB_STATE_ERROR; } st->read_state = READ_STATE_BODY; /* Fall through */ case READ_STATE_BODY: if (SSL_CONNECTION_IS_DTLS(s)) { /* * Actually we already have the body, but we give DTLS the * opportunity to do any further processing. */ ret = dtls_get_message_body(s, &len); } else { ret = tls_get_message_body(s, &len); } if (ret == 0) { /* Could be non-blocking IO */ return SUB_STATE_ERROR; } s->first_packet = 0; if (!PACKET_buf_init(&pkt, s->init_msg, len)) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return SUB_STATE_ERROR; } ret = process_message(s, &pkt); /* Discard the packet data */ s->init_num = 0; switch (ret) { case MSG_PROCESS_ERROR: check_fatal(s); return SUB_STATE_ERROR; case MSG_PROCESS_FINISHED_READING: if (SSL_CONNECTION_IS_DTLS(s)) { dtls1_stop_timer(s); } return SUB_STATE_FINISHED; case MSG_PROCESS_CONTINUE_PROCESSING: st->read_state = READ_STATE_POST_PROCESS; st->read_state_work = WORK_MORE_A; break; default: st->read_state = READ_STATE_HEADER; break; } break; case READ_STATE_POST_PROCESS: st->read_state_work = post_process_message(s, st->read_state_work); switch (st->read_state_work) { case WORK_ERROR: check_fatal(s); /* Fall through */ case WORK_MORE_A: case WORK_MORE_B: case WORK_MORE_C: return SUB_STATE_ERROR; case WORK_FINISHED_CONTINUE: st->read_state = READ_STATE_HEADER; break; case WORK_FINISHED_STOP: if (SSL_CONNECTION_IS_DTLS(s)) { dtls1_stop_timer(s); } return SUB_STATE_FINISHED; } break; default: /* Shouldn't happen */ SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return SUB_STATE_ERROR; } } } /* * Send a previously constructed message to the peer. */ static int statem_do_write(SSL_CONNECTION *s) { OSSL_STATEM *st = &s->statem; if (st->hand_state == TLS_ST_CW_CHANGE || st->hand_state == TLS_ST_SW_CHANGE) { if (SSL_CONNECTION_IS_DTLS(s)) return dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC); else return ssl3_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC); } else { return ssl_do_write(s); } } /* * Initialise the MSG_FLOW_WRITING sub-state machine */ static void init_write_state_machine(SSL_CONNECTION *s) { OSSL_STATEM *st = &s->statem; st->write_state = WRITE_STATE_TRANSITION; } /* * This function implements the sub-state machine when the message flow is in * MSG_FLOW_WRITING. The valid sub-states and transitions are: * * +-> WRITE_STATE_TRANSITION ------> [SUB_STATE_FINISHED] * | | * | v * | WRITE_STATE_PRE_WORK -----> [SUB_STATE_END_HANDSHAKE] * | | * | v * | WRITE_STATE_SEND * | | * | v * | WRITE_STATE_POST_WORK * | | * +-------------+ * * WRITE_STATE_TRANSITION transitions the state of the handshake state machine * WRITE_STATE_PRE_WORK performs any work necessary to prepare the later * sending of the message. This could result in an NBIO event occurring in * which case control returns to the calling application. When this function * is recalled we will resume in the same state where we left off. * * WRITE_STATE_SEND sends the message and performs any work to be done after * sending. * * WRITE_STATE_POST_WORK performs any work necessary after the sending of the * message has been completed. As for WRITE_STATE_PRE_WORK this could also * result in an NBIO event. */ static SUB_STATE_RETURN write_state_machine(SSL_CONNECTION *s) { OSSL_STATEM *st = &s->statem; int ret; WRITE_TRAN(*transition) (SSL_CONNECTION *s); WORK_STATE(*pre_work) (SSL_CONNECTION *s, WORK_STATE wst); WORK_STATE(*post_work) (SSL_CONNECTION *s, WORK_STATE wst); int (*get_construct_message_f) (SSL_CONNECTION *s, CON_FUNC_RETURN (**confunc) (SSL_CONNECTION *s, WPACKET *pkt), int *mt); void (*cb) (const SSL *ssl, int type, int val) = NULL; CON_FUNC_RETURN (*confunc) (SSL_CONNECTION *s, WPACKET *pkt); int mt; WPACKET pkt; SSL *ssl = SSL_CONNECTION_GET_USER_SSL(s); cb = get_callback(s); if (s->server) { transition = ossl_statem_server_write_transition; pre_work = ossl_statem_server_pre_work; post_work = ossl_statem_server_post_work; get_construct_message_f = ossl_statem_server_construct_message; } else { transition = ossl_statem_client_write_transition; pre_work = ossl_statem_client_pre_work; post_work = ossl_statem_client_post_work; get_construct_message_f = ossl_statem_client_construct_message; } while (1) { switch (st->write_state) { case WRITE_STATE_TRANSITION: if (cb != NULL) { /* Notify callback of an impending state change */ if (s->server) cb(ssl, SSL_CB_ACCEPT_LOOP, 1); else cb(ssl, SSL_CB_CONNECT_LOOP, 1); } switch (transition(s)) { case WRITE_TRAN_CONTINUE: st->write_state = WRITE_STATE_PRE_WORK; st->write_state_work = WORK_MORE_A; break; case WRITE_TRAN_FINISHED: return SUB_STATE_FINISHED; break; case WRITE_TRAN_ERROR: check_fatal(s); return SUB_STATE_ERROR; } break; case WRITE_STATE_PRE_WORK: switch (st->write_state_work = pre_work(s, st->write_state_work)) { case WORK_ERROR: check_fatal(s); /* Fall through */ case WORK_MORE_A: case WORK_MORE_B: case WORK_MORE_C: return SUB_STATE_ERROR; case WORK_FINISHED_CONTINUE: st->write_state = WRITE_STATE_SEND; break; case WORK_FINISHED_STOP: return SUB_STATE_END_HANDSHAKE; } if (!get_construct_message_f(s, &confunc, &mt)) { /* SSLfatal() already called */ return SUB_STATE_ERROR; } if (mt == SSL3_MT_DUMMY) { /* Skip construction and sending. This isn't a "real" state */ st->write_state = WRITE_STATE_POST_WORK; st->write_state_work = WORK_MORE_A; break; } if (!WPACKET_init(&pkt, s->init_buf) || !ssl_set_handshake_header(s, &pkt, mt)) { WPACKET_cleanup(&pkt); SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return SUB_STATE_ERROR; } if (confunc != NULL) { CON_FUNC_RETURN tmpret; tmpret = confunc(s, &pkt); if (tmpret == CON_FUNC_ERROR) { WPACKET_cleanup(&pkt); check_fatal(s); return SUB_STATE_ERROR; } else if (tmpret == CON_FUNC_DONT_SEND) { /* * The construction function decided not to construct the * message after all and continue. Skip sending. */ WPACKET_cleanup(&pkt); st->write_state = WRITE_STATE_POST_WORK; st->write_state_work = WORK_MORE_A; break; } /* else success */ } if (!ssl_close_construct_packet(s, &pkt, mt) || !WPACKET_finish(&pkt)) { WPACKET_cleanup(&pkt); SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return SUB_STATE_ERROR; } /* Fall through */ case WRITE_STATE_SEND: if (SSL_CONNECTION_IS_DTLS(s) && st->use_timer) { dtls1_start_timer(s); } ret = statem_do_write(s); if (ret <= 0) { return SUB_STATE_ERROR; } st->write_state = WRITE_STATE_POST_WORK; st->write_state_work = WORK_MORE_A; /* Fall through */ case WRITE_STATE_POST_WORK: switch (st->write_state_work = post_work(s, st->write_state_work)) { case WORK_ERROR: check_fatal(s); /* Fall through */ case WORK_MORE_A: case WORK_MORE_B: case WORK_MORE_C: return SUB_STATE_ERROR; case WORK_FINISHED_CONTINUE: st->write_state = WRITE_STATE_TRANSITION; break; case WORK_FINISHED_STOP: return SUB_STATE_END_HANDSHAKE; } break; default: SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); return SUB_STATE_ERROR; } } } /* * Flush the write BIO */ int statem_flush(SSL_CONNECTION *s) { s->rwstate = SSL_WRITING; if (BIO_flush(s->wbio) <= 0) { return 0; } s->rwstate = SSL_NOTHING; return 1; } /* * Called by the record layer to determine whether application data is * allowed to be received in the current handshake state or not. * * Return values are: * 1: Yes (application data allowed) * 0: No (application data not allowed) */ int ossl_statem_app_data_allowed(SSL_CONNECTION *s) { OSSL_STATEM *st = &s->statem; if (st->state == MSG_FLOW_UNINITED) return 0; if (!s->s3.in_read_app_data || (s->s3.total_renegotiations == 0)) return 0; if (s->server) { /* * If we're a server and we haven't got as far as writing our * ServerHello yet then we allow app data */ if (st->hand_state == TLS_ST_BEFORE || st->hand_state == TLS_ST_SR_CLNT_HELLO) return 1; } else { /* * If we're a client and we haven't read the ServerHello yet then we * allow app data */ if (st->hand_state == TLS_ST_CW_CLNT_HELLO) return 1; } return 0; } /* * This function returns 1 if TLS exporter is ready to export keying * material, or 0 if otherwise. */ int ossl_statem_export_allowed(SSL_CONNECTION *s) { return s->s3.previous_server_finished_len != 0 && s->statem.hand_state != TLS_ST_SW_FINISHED; } /* * Return 1 if early TLS exporter is ready to export keying material, * or 0 if otherwise. */ int ossl_statem_export_early_allowed(SSL_CONNECTION *s) { /* * The early exporter secret is only present on the server if we * have accepted early_data. It is present on the client as long * as we have sent early_data. */ return s->ext.early_data == SSL_EARLY_DATA_ACCEPTED || (!s->server && s->ext.early_data != SSL_EARLY_DATA_NOT_SENT); }