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			972 lines
		
	
	
	
		
			30 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			972 lines
		
	
	
	
		
			30 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * Copyright 2015-2019 The OpenSSL Project Authors. All Rights Reserved.
 | |
|  *
 | |
|  * Licensed under the OpenSSL license (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_put_error(ERR_LIB_SSL, func, reason, file, line);
 | |
|     /* 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);
 | |
| }
 |