| /* |
| * Copyright 2015-2018 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/cryptlib.h" |
| #include <openssl/rand.h> |
| #include "../ssl_local.h" |
| #include "statem_local.h" |
| #include <assert.h> |
| |
| /* |
| * 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 *s, int server); |
| static void init_read_state_machine(SSL *s); |
| static SUB_STATE_RETURN read_state_machine(SSL *s); |
| static void init_write_state_machine(SSL *s); |
| static SUB_STATE_RETURN write_state_machine(SSL *s); |
| |
| OSSL_HANDSHAKE_STATE SSL_get_state(const SSL *ssl) |
| { |
| return ssl->statem.hand_state; |
| } |
| |
| int SSL_in_init(const SSL *s) |
| { |
| return s->statem.in_init; |
| } |
| |
| int SSL_is_init_finished(const SSL *s) |
| { |
| return !(s->statem.in_init) && (s->statem.hand_state == TLS_ST_OK); |
| } |
| |
| int SSL_in_before(const SSL *s) |
| { |
| /* |
| * 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 (s->statem.hand_state == TLS_ST_BEFORE) |
| && (s->statem.state == MSG_FLOW_UNINITED); |
| } |
| |
| /* |
| * Clear the state machine state and reset back to MSG_FLOW_UNINITED |
| */ |
| void ossl_statem_clear(SSL *s) |
| { |
| s->statem.state = MSG_FLOW_UNINITED; |
| s->statem.hand_state = TLS_ST_BEFORE; |
| s->statem.in_init = 1; |
| s->statem.no_cert_verify = 0; |
| } |
| |
| /* |
| * Set the state machine up ready for a renegotiation handshake |
| */ |
| void ossl_statem_set_renegotiate(SSL *s) |
| { |
| s->statem.in_init = 1; |
| s->statem.request_state = TLS_ST_SW_HELLO_REQ; |
| } |
| |
| /* |
| * Put the state machine into an error state and send an alert if appropriate. |
| * This is a permanent error for the current connection. |
| */ |
| void ossl_statem_fatal(SSL *s, int al, int func, int reason, const char *file, |
| int line) |
| { |
| ERR_raise(ERR_LIB_SSL, reason); |
| ERR_set_debug(file, line, NULL); /* Override what ERR_raise set */ |
| /* We shouldn't call SSLfatal() twice. Once is enough */ |
| if (s->statem.in_init && s->statem.state == MSG_FLOW_ERROR) |
| return; |
| s->statem.in_init = 1; |
| s->statem.state = MSG_FLOW_ERROR; |
| if (al != SSL_AD_NO_ALERT |
| && s->statem.enc_write_state != ENC_WRITE_STATE_INVALID) |
| ssl3_send_alert(s, SSL3_AL_FATAL, 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, f) \ |
| do { \ |
| if (!ossl_assert((s)->statem.in_init \ |
| && (s)->statem.state == MSG_FLOW_ERROR)) \ |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, (f), \ |
| 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 *s) |
| { |
| if (s->statem.state == MSG_FLOW_ERROR) |
| return 1; |
| |
| return 0; |
| } |
| |
| void ossl_statem_set_in_init(SSL *s, int init) |
| { |
| s->statem.in_init = init; |
| } |
| |
| int ossl_statem_get_in_handshake(SSL *s) |
| { |
| return s->statem.in_handshake; |
| } |
| |
| void ossl_statem_set_in_handshake(SSL *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 *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 *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 *s) |
| { |
| s->statem.state = MSG_FLOW_UNINITED; |
| s->statem.in_init = 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) |
| { |
| return state_machine(s, 0); |
| } |
| |
| int ossl_statem_accept(SSL *s) |
| { |
| return state_machine(s, 1); |
| } |
| |
| typedef void (*info_cb) (const SSL *, int, int); |
| |
| static info_cb get_callback(SSL *s) |
| { |
| if (s->info_callback != NULL) |
| return s->info_callback; |
| else if (s->ctx->info_callback != NULL) |
| return s->ctx->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 *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; |
| |
| 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(s) || SSL_in_before(s)) { |
| /* |
| * 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(s)) |
| return -1; |
| } |
| #ifndef OPENSSL_NO_SCTP |
| if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) { |
| /* |
| * Notify SCTP BIO socket to enter handshake mode and prevent stream |
| * identifier other than 0. |
| */ |
| BIO_ctrl(SSL_get_wbio(s), 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_IS_TLS13(s)) |
| cb(s, 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_IS_DTLS(s)) { |
| if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00) && |
| (server || (s->version & 0xff00) != (DTLS1_BAD_VER & 0xff00))) { |
| SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_STATE_MACHINE, |
| ERR_R_INTERNAL_ERROR); |
| goto end; |
| } |
| } else { |
| if ((s->version >> 8) != SSL3_VERSION_MAJOR) { |
| SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_STATE_MACHINE, |
| ERR_R_INTERNAL_ERROR); |
| goto end; |
| } |
| } |
| |
| if (!ssl_security(s, SSL_SECOP_VERSION, 0, s->version, NULL)) { |
| SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_STATE_MACHINE, |
| ERR_R_INTERNAL_ERROR); |
| goto end; |
| } |
| |
| if (s->init_buf == NULL) { |
| if ((buf = BUF_MEM_new()) == NULL) { |
| SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_STATE_MACHINE, |
| ERR_R_INTERNAL_ERROR); |
| goto end; |
| } |
| if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) { |
| SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_STATE_MACHINE, |
| ERR_R_INTERNAL_ERROR); |
| goto end; |
| } |
| s->init_buf = buf; |
| buf = NULL; |
| } |
| |
| if (!ssl3_setup_buffers(s)) { |
| SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_STATE_MACHINE, |
| ERR_R_INTERNAL_ERROR); |
| goto end; |
| } |
| 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_IS_DTLS(s) || !BIO_dgram_is_sctp(SSL_get_wbio(s))) |
| #endif |
| if (!ssl_init_wbio_buffer(s)) { |
| SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_STATE_MACHINE, |
| ERR_R_INTERNAL_ERROR); |
| goto end; |
| } |
| |
| if ((SSL_in_before(s)) |
| || 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, SSL_F_STATE_MACHINE); |
| SSLerr(SSL_F_STATE_MACHINE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
| goto end; |
| } |
| } |
| |
| ret = 1; |
| |
| end: |
| st->in_handshake--; |
| |
| #ifndef OPENSSL_NO_SCTP |
| if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) { |
| /* |
| * Notify SCTP BIO socket to leave handshake mode and allow stream |
| * identifier other than 0. |
| */ |
| BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE, |
| st->in_handshake, NULL); |
| } |
| #endif |
| |
| BUF_MEM_free(buf); |
| if (cb != NULL) { |
| if (server) |
| cb(s, SSL_CB_ACCEPT_EXIT, ret); |
| else |
| cb(s, SSL_CB_CONNECT_EXIT, ret); |
| } |
| return ret; |
| } |
| |
| /* |
| * Initialise the MSG_FLOW_READING sub-state machine |
| */ |
| static void init_read_state_machine(SSL *s) |
| { |
| OSSL_STATEM *st = &s->statem; |
| |
| st->read_state = READ_STATE_HEADER; |
| } |
| |
| static int grow_init_buf(SSL *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 *s) |
| { |
| OSSL_STATEM *st = &s->statem; |
| int ret, mt; |
| size_t len = 0; |
| int (*transition) (SSL *s, int mt); |
| PACKET pkt; |
| MSG_PROCESS_RETURN(*process_message) (SSL *s, PACKET *pkt); |
| WORK_STATE(*post_process_message) (SSL *s, WORK_STATE wst); |
| size_t (*max_message_size) (SSL *s); |
| void (*cb) (const SSL *ssl, int type, int val) = NULL; |
| |
| 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_IS_DTLS(s)) { |
| /* |
| * In DTLS we get the whole message in one go - header and body |
| */ |
| ret = dtls_get_message(s, &mt, &len); |
| } 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(s, SSL_CB_ACCEPT_LOOP, 1); |
| else |
| cb(s, 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_F_READ_STATE_MACHINE, |
| SSL_R_EXCESSIVE_MESSAGE_SIZE); |
| return SUB_STATE_ERROR; |
| } |
| |
| /* dtls_get_message already did this */ |
| if (!SSL_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, SSL_F_READ_STATE_MACHINE, |
| ERR_R_BUF_LIB); |
| return SUB_STATE_ERROR; |
| } |
| |
| st->read_state = READ_STATE_BODY; |
| /* Fall through */ |
| |
| case READ_STATE_BODY: |
| if (!SSL_IS_DTLS(s)) { |
| /* We already got this above for DTLS */ |
| 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, SSL_F_READ_STATE_MACHINE, |
| 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, SSL_F_READ_STATE_MACHINE); |
| return SUB_STATE_ERROR; |
| |
| case MSG_PROCESS_FINISHED_READING: |
| if (SSL_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, SSL_F_READ_STATE_MACHINE); |
| /* 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_IS_DTLS(s)) { |
| dtls1_stop_timer(s); |
| } |
| return SUB_STATE_FINISHED; |
| } |
| break; |
| |
| default: |
| /* Shouldn't happen */ |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_READ_STATE_MACHINE, |
| ERR_R_INTERNAL_ERROR); |
| return SUB_STATE_ERROR; |
| } |
| } |
| } |
| |
| /* |
| * Send a previously constructed message to the peer. |
| */ |
| static int statem_do_write(SSL *s) |
| { |
| OSSL_STATEM *st = &s->statem; |
| |
| if (st->hand_state == TLS_ST_CW_CHANGE |
| || st->hand_state == TLS_ST_SW_CHANGE) { |
| if (SSL_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 *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 *s) |
| { |
| OSSL_STATEM *st = &s->statem; |
| int ret; |
| WRITE_TRAN(*transition) (SSL *s); |
| WORK_STATE(*pre_work) (SSL *s, WORK_STATE wst); |
| WORK_STATE(*post_work) (SSL *s, WORK_STATE wst); |
| int (*get_construct_message_f) (SSL *s, WPACKET *pkt, |
| int (**confunc) (SSL *s, WPACKET *pkt), |
| int *mt); |
| void (*cb) (const SSL *ssl, int type, int val) = NULL; |
| int (*confunc) (SSL *s, WPACKET *pkt); |
| int mt; |
| WPACKET pkt; |
| |
| 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(s, SSL_CB_ACCEPT_LOOP, 1); |
| else |
| cb(s, 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, SSL_F_WRITE_STATE_MACHINE); |
| 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, SSL_F_WRITE_STATE_MACHINE); |
| /* 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, &pkt, &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, SSL_F_WRITE_STATE_MACHINE, |
| ERR_R_INTERNAL_ERROR); |
| return SUB_STATE_ERROR; |
| } |
| if (confunc != NULL && !confunc(s, &pkt)) { |
| WPACKET_cleanup(&pkt); |
| check_fatal(s, SSL_F_WRITE_STATE_MACHINE); |
| return SUB_STATE_ERROR; |
| } |
| if (!ssl_close_construct_packet(s, &pkt, mt) |
| || !WPACKET_finish(&pkt)) { |
| WPACKET_cleanup(&pkt); |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_WRITE_STATE_MACHINE, |
| ERR_R_INTERNAL_ERROR); |
| return SUB_STATE_ERROR; |
| } |
| |
| /* Fall through */ |
| |
| case WRITE_STATE_SEND: |
| if (SSL_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, SSL_F_WRITE_STATE_MACHINE); |
| /* 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, SSL_F_WRITE_STATE_MACHINE, |
| ERR_R_INTERNAL_ERROR); |
| return SUB_STATE_ERROR; |
| } |
| } |
| } |
| |
| /* |
| * Flush the write BIO |
| */ |
| int statem_flush(SSL *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 *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 *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 *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); |
| } |
