Exemplo n.º 1
0
void
dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
	{
	memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
	msg_hdr->type = *(data++);
	n2l3(data, msg_hdr->msg_len);

	n2s(data, msg_hdr->seq);
	n2l3(data, msg_hdr->frag_off);
	n2l3(data, msg_hdr->frag_len);
	}
Exemplo n.º 2
0
/* Obtain handshake message of message type 'mt' (any if mt == -1),
 * maximum acceptable body length 'max'.
 * The first four bytes (msg_type and length) are read in state 'st1',
 * the body is read in state 'stn'.
 */
long ssl3_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
	{
	unsigned char *p;
	unsigned long l;
	long n;
	int i,al;

	if (s->s3->tmp.reuse_message)
		{
		s->s3->tmp.reuse_message=0;
		if ((mt >= 0) && (s->s3->tmp.message_type != mt))
			{
			al=SSL_AD_UNEXPECTED_MESSAGE;
			SSLerr(SSL_F_SSL3_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
			goto f_err;
			}
		*ok=1;
		s->init_msg = s->init_buf->data + 4;
		s->init_num = (int)s->s3->tmp.message_size;
		return s->init_num;
		}

	p=(unsigned char *)s->init_buf->data;

	if (s->state == st1) /* s->init_num < 4 */
		{
		int skip_message;

		do
			{
			while (s->init_num < 4)
				{
				i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
					&p[s->init_num],4 - s->init_num, 0);
				if (i <= 0)
					{
					s->rwstate=SSL_READING;
					*ok = 0;
					return i;
					}
				s->init_num+=i;
				}
			
			skip_message = 0;
			if (!s->server)
				if (p[0] == SSL3_MT_HELLO_REQUEST)
					/* The server may always send 'Hello Request' messages --
					 * we are doing a handshake anyway now, so ignore them
					 * if their format is correct. Does not count for
					 * 'Finished' MAC. */
					if (p[1] == 0 && p[2] == 0 &&p[3] == 0)
						{
						s->init_num = 0;
						skip_message = 1;

						if (s->msg_callback)
							s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, p, 4, s, s->msg_callback_arg);
						}
			}
		while (skip_message);

		/* s->init_num == 4 */

		if ((mt >= 0) && (*p != mt))
			{
			al=SSL_AD_UNEXPECTED_MESSAGE;
			SSLerr(SSL_F_SSL3_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
			goto f_err;
			}
		if ((mt < 0) && (*p == SSL3_MT_CLIENT_HELLO) &&
					(st1 == SSL3_ST_SR_CERT_A) &&
					(stn == SSL3_ST_SR_CERT_B))
			{
			/* At this point we have got an MS SGC second client
			 * hello (maybe we should always allow the client to
			 * start a new handshake?). We need to restart the mac.
			 * Don't increment {num,total}_renegotiations because
			 * we have not completed the handshake. */
			ssl3_init_finished_mac(s);
			}

		s->s3->tmp.message_type= *(p++);

		n2l3(p,l);
		if (l > (unsigned long)max)
			{
			al=SSL_AD_ILLEGAL_PARAMETER;
			SSLerr(SSL_F_SSL3_GET_MESSAGE,SSL_R_EXCESSIVE_MESSAGE_SIZE);
			goto f_err;
			}
		if (l > (INT_MAX-4)) /* BUF_MEM_grow takes an 'int' parameter */
			{
			al=SSL_AD_ILLEGAL_PARAMETER;
			SSLerr(SSL_F_SSL3_GET_MESSAGE,SSL_R_EXCESSIVE_MESSAGE_SIZE);
			goto f_err;
			}
		if (l && !BUF_MEM_grow_clean(s->init_buf,(int)l+4))
			{
			SSLerr(SSL_F_SSL3_GET_MESSAGE,ERR_R_BUF_LIB);
			goto err;
			}
		s->s3->tmp.message_size=l;
		s->state=stn;

		s->init_msg = s->init_buf->data + 4;
		s->init_num = 0;
		}

	/* next state (stn) */
	p = s->init_msg;
	n = s->s3->tmp.message_size - s->init_num;
	while (n > 0)
		{
		i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,&p[s->init_num],n,0);
		if (i <= 0)
			{
			s->rwstate=SSL_READING;
			*ok = 0;
			return i;
			}
		s->init_num += i;
		n -= i;
		}

#ifndef OPENSSL_NO_NEXTPROTONEG
	/* If receiving Finished, record MAC of prior handshake messages for
	 * Finished verification. */
	if (*s->init_buf->data == SSL3_MT_FINISHED)
		ssl3_take_mac(s);
#endif

	/* Feed this message into MAC computation. */
	ssl3_finish_mac(s, (unsigned char *)s->init_buf->data, s->init_num + 4);
	if (s->msg_callback)
		s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data, (size_t)s->init_num + 4, s, s->msg_callback_arg);
	*ok=1;
	return s->init_num;
f_err:
	ssl3_send_alert(s,SSL3_AL_FATAL,al);
err:
	*ok=0;
	return(-1);
	}
Exemplo n.º 3
0
int tls_get_message_header(SSL *s, int *mt)
{
    /* s->init_num < SSL3_HM_HEADER_LENGTH */
    int skip_message, i, recvd_type, al;
    unsigned char *p;
    unsigned long l;

    p = (unsigned char *)s->init_buf->data;

    do {
        while (s->init_num < SSL3_HM_HEADER_LENGTH) {
            i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type,
                                          &p[s->init_num],
                                          SSL3_HM_HEADER_LENGTH - s->init_num,
                                          0);
            if (i <= 0) {
                s->rwstate = SSL_READING;
                return 0;
            }
            if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
                /*
                 * A ChangeCipherSpec must be a single byte and may not occur
                 * in the middle of a handshake message.
                 */
                if (s->init_num != 0 || i != 1 || p[0] != SSL3_MT_CCS) {
                    al = SSL_AD_UNEXPECTED_MESSAGE;
                    SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER,
                           SSL_R_BAD_CHANGE_CIPHER_SPEC);
                    goto f_err;
                }
                s->s3->tmp.message_type = *mt = SSL3_MT_CHANGE_CIPHER_SPEC;
                s->init_num = i - 1;
                s->s3->tmp.message_size = i;
                return 1;
            } else if (recvd_type != SSL3_RT_HANDSHAKE) {
                al = SSL_AD_UNEXPECTED_MESSAGE;
                SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_CCS_RECEIVED_EARLY);
                goto f_err;
            }
            s->init_num += i;
        }

        skip_message = 0;
        if (!s->server)
            if (p[0] == SSL3_MT_HELLO_REQUEST)
                /*
                 * The server may always send 'Hello Request' messages --
                 * we are doing a handshake anyway now, so ignore them if
                 * their format is correct. Does not count for 'Finished'
                 * MAC.
                 */
                if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
                    s->init_num = 0;
                    skip_message = 1;

                    if (s->msg_callback)
                        s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
                                        p, SSL3_HM_HEADER_LENGTH, s,
                                        s->msg_callback_arg);
                }
    } while (skip_message);
    /* s->init_num == SSL3_HM_HEADER_LENGTH */

    *mt = *p;
    s->s3->tmp.message_type = *(p++);

    if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
        /*
         * Only happens with SSLv3+ in an SSLv2 backward compatible
         * ClientHello
         *
         * Total message size is the remaining record bytes to read
         * plus the SSL3_HM_HEADER_LENGTH bytes that we already read
         */
        l = RECORD_LAYER_get_rrec_length(&s->rlayer)
            + SSL3_HM_HEADER_LENGTH;
        s->s3->tmp.message_size = l;

        s->init_msg = s->init_buf->data;
        s->init_num = SSL3_HM_HEADER_LENGTH;
    } else {
        n2l3(p, l);
        /* BUF_MEM_grow takes an 'int' parameter */
        if (l > (INT_MAX - SSL3_HM_HEADER_LENGTH)) {
            al = SSL_AD_ILLEGAL_PARAMETER;
            SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
            goto f_err;
        }
        s->s3->tmp.message_size = l;

        s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
        s->init_num = 0;
    }

    return 1;
 f_err:
    ssl3_send_alert(s, SSL3_AL_FATAL, al);
    return 0;
}
/*-
 * Return up to 'len' payload bytes received in 'type' records.
 * 'type' is one of the following:
 *
 *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 *   -  0 (during a shutdown, no data has to be returned)
 *
 * If we don't have stored data to work from, read a SSL/TLS record first
 * (possibly multiple records if we still don't have anything to return).
 *
 * This function must handle any surprises the peer may have for us, such as
 * Alert records (e.g. close_notify) or renegotiation requests. ChangeCipherSpec
 * messages are treated as if they were handshake messages *if* the |recd_type|
 * argument is non NULL.
 * Also if record payloads contain fragments too small to process, we store
 * them until there is enough for the respective protocol (the record protocol
 * may use arbitrary fragmentation and even interleaving):
 *     Change cipher spec protocol
 *             just 1 byte needed, no need for keeping anything stored
 *     Alert protocol
 *             2 bytes needed (AlertLevel, AlertDescription)
 *     Handshake protocol
 *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 *             to detect unexpected Client Hello and Hello Request messages
 *             here, anything else is handled by higher layers
 *     Application data protocol
 *             none of our business
 */
int dtls1_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf,
                     int len, int peek)
{
    int al, i, j, ret;
    unsigned int n;
    SSL3_RECORD *rr;
    void (*cb) (const SSL *ssl, int type2, int val) = NULL;

    if (!SSL3_BUFFER_is_initialised(&s->rlayer.rbuf)) {
        /* Not initialized yet */
        if (!ssl3_setup_buffers(s))
            return (-1);
    }

    if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
         (type != SSL3_RT_HANDSHAKE)) ||
        (peek && (type != SSL3_RT_APPLICATION_DATA))) {
        SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
        return -1;
    }

    /*
     * check whether there's a handshake message (client hello?) waiting
     */
    if ((ret = have_handshake_fragment(s, type, buf, len))) {
        *recvd_type = SSL3_RT_HANDSHAKE;
        return ret;
    }

    /*
     * Now s->rlayer.d->handshake_fragment_len == 0 if
     * type == SSL3_RT_HANDSHAKE.
     */

    if (!ossl_statem_get_in_handshake(s) && SSL_in_init(s))
    {
        /* type == SSL3_RT_APPLICATION_DATA */
        i = s->handshake_func(s);
        if (i < 0)
            return (i);
        if (i == 0) {
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
            return (-1);
        }
    }

 start:
    s->rwstate = SSL_NOTHING;

    /*-
     * s->s3->rrec.type         - is the type of record
     * s->s3->rrec.data,    - data
     * s->s3->rrec.off,     - offset into 'data' for next read
     * s->s3->rrec.length,  - number of bytes.
     */
    rr = s->rlayer.rrec;

    /*
     * We are not handshaking and have no data yet, so process data buffered
     * during the last handshake in advance, if any.
     */
    if (SSL_is_init_finished(s) && SSL3_RECORD_get_length(rr) == 0) {
        pitem *item;
        item = pqueue_pop(s->rlayer.d->buffered_app_data.q);
        if (item) {
#ifndef OPENSSL_NO_SCTP
            /* Restore bio_dgram_sctp_rcvinfo struct */
            if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
                DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
                BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
                         sizeof(rdata->recordinfo), &rdata->recordinfo);
            }
#endif

            dtls1_copy_record(s, item);

            OPENSSL_free(item->data);
            pitem_free(item);
        }
    }

    /* Check for timeout */
    if (dtls1_handle_timeout(s) > 0)
        goto start;

    /* get new packet if necessary */
    if ((SSL3_RECORD_get_length(rr) == 0)
        || (s->rlayer.rstate == SSL_ST_READ_BODY)) {
        ret = dtls1_get_record(s);
        if (ret <= 0) {
            ret = dtls1_read_failed(s, ret);
            /* anything other than a timeout is an error */
            if (ret <= 0)
                return (ret);
            else
                goto start;
        }
    }

    /*
     * Reset the count of consecutive warning alerts if we've got a non-empty
     * record that isn't an alert.
     */
    if (SSL3_RECORD_get_type(rr) != SSL3_RT_ALERT
            && SSL3_RECORD_get_length(rr) != 0)
        s->rlayer.alert_count = 0;

    /* we now have a packet which can be read and processed */

    if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
                                   * reset by ssl3_get_finished */
        && (SSL3_RECORD_get_type(rr) != SSL3_RT_HANDSHAKE)) {
        /*
         * We now have application data between CCS and Finished. Most likely
         * the packets were reordered on their way, so buffer the application
         * data for later processing rather than dropping the connection.
         */
        if (dtls1_buffer_record(s, &(s->rlayer.d->buffered_app_data),
                                SSL3_RECORD_get_seq_num(rr)) < 0) {
            SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
            return -1;
        }
        SSL3_RECORD_set_length(rr, 0);
        goto start;
    }

    /*
     * If the other end has shut down, throw anything we read away (even in
     * 'peek' mode)
     */
    if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
        SSL3_RECORD_set_length(rr, 0);
        s->rwstate = SSL_NOTHING;
        return (0);
    }

    if (type == SSL3_RECORD_get_type(rr)
        || (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC
            && type == SSL3_RT_HANDSHAKE && recvd_type != NULL)) {
        /*
         * SSL3_RT_APPLICATION_DATA or
         * SSL3_RT_HANDSHAKE or
         * SSL3_RT_CHANGE_CIPHER_SPEC
         */
        /*
         * make sure that we are not getting application data when we are
         * doing a handshake for the first time
         */
        if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
            (s->enc_read_ctx == NULL)) {
            al = SSL_AD_UNEXPECTED_MESSAGE;
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
            goto f_err;
        }

        if (recvd_type != NULL)
            *recvd_type = SSL3_RECORD_get_type(rr);

        if (len <= 0)
            return (len);

        if ((unsigned int)len > SSL3_RECORD_get_length(rr))
            n = SSL3_RECORD_get_length(rr);
        else
            n = (unsigned int)len;

        memcpy(buf, &(SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)]), n);
        if (!peek) {
            SSL3_RECORD_sub_length(rr, n);
            SSL3_RECORD_add_off(rr, n);
            if (SSL3_RECORD_get_length(rr) == 0) {
                s->rlayer.rstate = SSL_ST_READ_HEADER;
                SSL3_RECORD_set_off(rr, 0);
            }
        }
#ifndef OPENSSL_NO_SCTP
        /*
         * We might had to delay a close_notify alert because of reordered
         * app data. If there was an alert and there is no message to read
         * anymore, finally set shutdown.
         */
        if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
            s->d1->shutdown_received
            && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
            s->shutdown |= SSL_RECEIVED_SHUTDOWN;
            return (0);
        }
#endif
        return (n);
    }

    /*
     * If we get here, then type != rr->type; if we have a handshake message,
     * then it was unexpected (Hello Request or Client Hello).
     */

    /*
     * In case of record types for which we have 'fragment' storage, fill
     * that so that we can process the data at a fixed place.
     */
    {
        unsigned int k, dest_maxlen = 0;
        unsigned char *dest = NULL;
        unsigned int *dest_len = NULL;

        if (SSL3_RECORD_get_type(rr) == SSL3_RT_HANDSHAKE) {
            dest_maxlen = sizeof s->rlayer.d->handshake_fragment;
            dest = s->rlayer.d->handshake_fragment;
            dest_len = &s->rlayer.d->handshake_fragment_len;
        } else if (SSL3_RECORD_get_type(rr) == SSL3_RT_ALERT) {
            dest_maxlen = sizeof(s->rlayer.d->alert_fragment);
            dest = s->rlayer.d->alert_fragment;
            dest_len = &s->rlayer.d->alert_fragment_len;
        }
#ifndef OPENSSL_NO_HEARTBEATS
        else if (SSL3_RECORD_get_type(rr) == DTLS1_RT_HEARTBEAT) {
            /* We allow a 0 return */
            if (dtls1_process_heartbeat(s, SSL3_RECORD_get_data(rr),
                                        SSL3_RECORD_get_length(rr)) < 0) {
                return -1;
            }
            /* Exit and notify application to read again */
            SSL3_RECORD_set_length(rr, 0);
            s->rwstate = SSL_READING;
            BIO_clear_retry_flags(SSL_get_rbio(s));
            BIO_set_retry_read(SSL_get_rbio(s));
            return (-1);
        }
#endif
        /* else it's a CCS message, or application data or wrong */
        else if (SSL3_RECORD_get_type(rr) != SSL3_RT_CHANGE_CIPHER_SPEC) {
            /*
             * Application data while renegotiating is allowed. Try again
             * reading.
             */
            if (SSL3_RECORD_get_type(rr) == SSL3_RT_APPLICATION_DATA) {
                BIO *bio;
                s->s3->in_read_app_data = 2;
                bio = SSL_get_rbio(s);
                s->rwstate = SSL_READING;
                BIO_clear_retry_flags(bio);
                BIO_set_retry_read(bio);
                return (-1);
            }

            /* Not certain if this is the right error handling */
            al = SSL_AD_UNEXPECTED_MESSAGE;
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
            goto f_err;
        }

        if (dest_maxlen > 0) {
            /*
             * XDTLS: In a pathological case, the Client Hello may be
             * fragmented--don't always expect dest_maxlen bytes
             */
            if (SSL3_RECORD_get_length(rr) < dest_maxlen) {
#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
                /*
                 * for normal alerts rr->length is 2, while
                 * dest_maxlen is 7 if we were to handle this
                 * non-existing alert...
                 */
                FIX ME;
#endif
                s->rlayer.rstate = SSL_ST_READ_HEADER;
                SSL3_RECORD_set_length(rr, 0);
                goto start;
            }

            /* now move 'n' bytes: */
            for (k = 0; k < dest_maxlen; k++) {
                dest[k] = SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)];
                SSL3_RECORD_add_off(rr, 1);
                SSL3_RECORD_add_length(rr, -1);
            }
            *dest_len = dest_maxlen;
        }
    }

    /*-
     * s->rlayer.d->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
     * s->rlayer.d->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
     * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
     */

    /* If we are a client, check for an incoming 'Hello Request': */
    if ((!s->server) &&
        (s->rlayer.d->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
        (s->rlayer.d->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
        (s->session != NULL) && (s->session->cipher != NULL)) {
        s->rlayer.d->handshake_fragment_len = 0;

        if ((s->rlayer.d->handshake_fragment[1] != 0) ||
            (s->rlayer.d->handshake_fragment[2] != 0) ||
            (s->rlayer.d->handshake_fragment[3] != 0)) {
            al = SSL_AD_DECODE_ERROR;
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST);
            goto f_err;
        }

        /*
         * no need to check sequence number on HELLO REQUEST messages
         */

        if (s->msg_callback)
            s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
                            s->rlayer.d->handshake_fragment, 4, s,
                            s->msg_callback_arg);

        if (SSL_is_init_finished(s) &&
            !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
            !s->s3->renegotiate) {
            s->d1->handshake_read_seq++;
            s->new_session = 1;
            ssl3_renegotiate(s);
            if (ssl3_renegotiate_check(s)) {
                i = s->handshake_func(s);
                if (i < 0)
                    return (i);
                if (i == 0) {
                    SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
                    return (-1);
                }

                if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
                    if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
                        /* no read-ahead left? */
                        BIO *bio;
                        /*
                         * In the case where we try to read application data,
                         * but we trigger an SSL handshake, we return -1 with
                         * the retry option set.  Otherwise renegotiation may
                         * cause nasty problems in the blocking world
                         */
                        s->rwstate = SSL_READING;
                        bio = SSL_get_rbio(s);
                        BIO_clear_retry_flags(bio);
                        BIO_set_retry_read(bio);
                        return (-1);
                    }
                }
            }
        }
        /*
         * we either finished a handshake or ignored the request, now try
         * again to obtain the (application) data we were asked for
         */
        goto start;
    }

    if (s->rlayer.d->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
        int alert_level = s->rlayer.d->alert_fragment[0];
        int alert_descr = s->rlayer.d->alert_fragment[1];

        s->rlayer.d->alert_fragment_len = 0;

        if (s->msg_callback)
            s->msg_callback(0, s->version, SSL3_RT_ALERT,
                            s->rlayer.d->alert_fragment, 2, s,
                            s->msg_callback_arg);

        if (s->info_callback != NULL)
            cb = s->info_callback;
        else if (s->ctx->info_callback != NULL)
            cb = s->ctx->info_callback;

        if (cb != NULL) {
            j = (alert_level << 8) | alert_descr;
            cb(s, SSL_CB_READ_ALERT, j);
        }

        if (alert_level == SSL3_AL_WARNING) {
            s->s3->warn_alert = alert_descr;

            s->rlayer.alert_count++;
            if (s->rlayer.alert_count == MAX_WARN_ALERT_COUNT) {
                al = SSL_AD_UNEXPECTED_MESSAGE;
                SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_TOO_MANY_WARN_ALERTS);
                goto f_err;
            }

            if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
#ifndef OPENSSL_NO_SCTP
                /*
                 * With SCTP and streams the socket may deliver app data
                 * after a close_notify alert. We have to check this first so
                 * that nothing gets discarded.
                 */
                if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
                    BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
                    s->d1->shutdown_received = 1;
                    s->rwstate = SSL_READING;
                    BIO_clear_retry_flags(SSL_get_rbio(s));
                    BIO_set_retry_read(SSL_get_rbio(s));
                    return -1;
                }
#endif
                s->shutdown |= SSL_RECEIVED_SHUTDOWN;
                return (0);
            }
#if 0
            /* XXX: this is a possible improvement in the future */
            /* now check if it's a missing record */
            if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
                unsigned short seq;
                unsigned int frag_off;
                unsigned char *p = &(s->rlayer.d->alert_fragment[2]);

                n2s(p, seq);
                n2l3(p, frag_off);

                dtls1_retransmit_message(s,
                                         dtls1_get_queue_priority
                                         (frag->msg_header.seq, 0), frag_off,
                                         &found);
                if (!found && SSL_in_init(s)) {
                    /*
                     * fprintf( stderr,"in init = %d\n", SSL_in_init(s));
                     */
                    /*
                     * requested a message not yet sent, send an alert
                     * ourselves
                     */
                    ssl3_send_alert(s, SSL3_AL_WARNING,
                                    DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
                }
            }
#endif
        } else if (alert_level == SSL3_AL_FATAL) {
            char tmp[16];

            s->rwstate = SSL_NOTHING;
            s->s3->fatal_alert = alert_descr;
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
            BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
            ERR_add_error_data(2, "SSL alert number ", tmp);
            s->shutdown |= SSL_RECEIVED_SHUTDOWN;
            SSL_CTX_remove_session(s->session_ctx, s->session);
            return (0);
        } else {
            al = SSL_AD_ILLEGAL_PARAMETER;
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
            goto f_err;
        }

        goto start;
    }

    if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
                                            * shutdown */
        s->rwstate = SSL_NOTHING;
        SSL3_RECORD_set_length(rr, 0);
        return (0);
    }

    if (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC) {
        /*
         * We can't process a CCS now, because previous handshake messages
         * are still missing, so just drop it.
         */
        SSL3_RECORD_set_length(rr, 0);
        goto start;
    }

    /*
     * Unexpected handshake message (Client Hello, or protocol violation)
     */
    if ((s->rlayer.d->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
        !ossl_statem_get_in_handshake(s)) {
        struct hm_header_st msg_hdr;

        /* this may just be a stale retransmit */
        dtls1_get_message_header(rr->data, &msg_hdr);
        if (SSL3_RECORD_get_epoch(rr) != s->rlayer.d->r_epoch) {
            SSL3_RECORD_set_length(rr, 0);
            goto start;
        }

        /*
         * If we are server, we may have a repeated FINISHED of the client
         * here, then retransmit our CCS and FINISHED.
         */
        if (msg_hdr.type == SSL3_MT_FINISHED) {
            if (dtls1_check_timeout_num(s) < 0)
                return -1;

            dtls1_retransmit_buffered_messages(s);
            SSL3_RECORD_set_length(rr, 0);
            goto start;
        }

        if (SSL_is_init_finished(s) &&
            !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
            ossl_statem_set_in_init(s, 1);
            s->renegotiate = 1;
            s->new_session = 1;
        }
        i = s->handshake_func(s);
        if (i < 0)
            return (i);
        if (i == 0) {
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
            return (-1);
        }

        if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
            if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
                /* no read-ahead left? */
                BIO *bio;
                /*
                 * In the case where we try to read application data, but we
                 * trigger an SSL handshake, we return -1 with the retry
                 * option set.  Otherwise renegotiation may cause nasty
                 * problems in the blocking world
                 */
                s->rwstate = SSL_READING;
                bio = SSL_get_rbio(s);
                BIO_clear_retry_flags(bio);
                BIO_set_retry_read(bio);
                return (-1);
            }
        }
        goto start;
    }

    switch (SSL3_RECORD_get_type(rr)) {
    default:
        /* TLS just ignores unknown message types */
        if (s->version == TLS1_VERSION) {
            SSL3_RECORD_set_length(rr, 0);
            goto start;
        }
        al = SSL_AD_UNEXPECTED_MESSAGE;
        SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
        goto f_err;
    case SSL3_RT_CHANGE_CIPHER_SPEC:
    case SSL3_RT_ALERT:
    case SSL3_RT_HANDSHAKE:
        /*
         * we already handled all of these, with the possible exception of
         * SSL3_RT_HANDSHAKE when ossl_statem_get_in_handshake(s) is true, but
         * that should not happen when type != rr->type
         */
        al = SSL_AD_UNEXPECTED_MESSAGE;
        SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
        goto f_err;
    case SSL3_RT_APPLICATION_DATA:
        /*
         * At this point, we were expecting handshake data, but have
         * application data.  If the library was running inside ssl3_read()
         * (i.e. in_read_app_data is set) and it makes sense to read
         * application data at this point (session renegotiation not yet
         * started), we will indulge it.
         */
        if (s->s3->in_read_app_data &&
            (s->s3->total_renegotiations != 0) &&
            ossl_statem_app_data_allowed(s)) {
            s->s3->in_read_app_data = 2;
            return (-1);
        } else {
            al = SSL_AD_UNEXPECTED_MESSAGE;
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
            goto f_err;
        }
    }
    /* not reached */

 f_err:
    ssl3_send_alert(s, SSL3_AL_FATAL, al);
    return (-1);
}
Exemplo n.º 5
0
/* Obtain handshake message of message type |msg_type| (any if |msg_type| == -1),
 * maximum acceptable body length |max|. The first four bytes (msg_type and
 * length) are read in state |header_state|, the body is read in state
 * |body_state|. */
long ssl3_get_message(SSL *ssl, int header_state, int body_state, int msg_type,
                      long max, enum ssl_hash_message_t hash_message, int *ok) {
  uint8_t *p;
  unsigned long l;
  long n;
  int al;

  if (ssl->s3->tmp.reuse_message) {
    /* A ssl_dont_hash_message call cannot be combined with reuse_message; the
     * ssl_dont_hash_message would have to have been applied to the previous
     * call. */
    assert(hash_message == ssl_hash_message);
    ssl->s3->tmp.reuse_message = 0;
    if (msg_type >= 0 && ssl->s3->tmp.message_type != msg_type) {
      al = SSL_AD_UNEXPECTED_MESSAGE;
      OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
      goto f_err;
    }
    *ok = 1;
    ssl->state = body_state;
    ssl->init_msg = (uint8_t *)ssl->init_buf->data + 4;
    ssl->init_num = (int)ssl->s3->tmp.message_size;
    return ssl->init_num;
  }

  p = (uint8_t *)ssl->init_buf->data;

  if (ssl->state == header_state) {
    assert(ssl->init_num < 4);

    for (;;) {
      while (ssl->init_num < 4) {
        int bytes_read = ssl3_read_bytes(
            ssl, SSL3_RT_HANDSHAKE, &p[ssl->init_num], 4 - ssl->init_num, 0);
        if (bytes_read <= 0) {
          *ok = 0;
          return bytes_read;
        }
        ssl->init_num += bytes_read;
      }

      static const uint8_t kHelloRequest[4] = {SSL3_MT_HELLO_REQUEST, 0, 0, 0};
      if (ssl->server || memcmp(p, kHelloRequest, sizeof(kHelloRequest)) != 0) {
        break;
      }

      /* The server may always send 'Hello Request' messages -- we are doing
       * a handshake anyway now, so ignore them if their format is correct.
       * Does not count for 'Finished' MAC. */
      ssl->init_num = 0;

      if (ssl->msg_callback) {
        ssl->msg_callback(0, ssl->version, SSL3_RT_HANDSHAKE, p, 4, ssl,
                        ssl->msg_callback_arg);
      }
    }

    /* ssl->init_num == 4 */

    if (msg_type >= 0 && *p != msg_type) {
      al = SSL_AD_UNEXPECTED_MESSAGE;
      OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
      goto f_err;
    }
    ssl->s3->tmp.message_type = *(p++);

    n2l3(p, l);
    if (l > (unsigned long)max) {
      al = SSL_AD_ILLEGAL_PARAMETER;
      OPENSSL_PUT_ERROR(SSL, SSL_R_EXCESSIVE_MESSAGE_SIZE);
      goto f_err;
    }

    if (l && !BUF_MEM_grow_clean(ssl->init_buf, l + 4)) {
      OPENSSL_PUT_ERROR(SSL, ERR_R_BUF_LIB);
      goto err;
    }
    ssl->s3->tmp.message_size = l;
    ssl->state = body_state;

    ssl->init_msg = (uint8_t *)ssl->init_buf->data + 4;
    ssl->init_num = 0;
  }

  /* next state (body_state) */
  p = ssl->init_msg;
  n = ssl->s3->tmp.message_size - ssl->init_num;
  while (n > 0) {
    int bytes_read =
        ssl3_read_bytes(ssl, SSL3_RT_HANDSHAKE, &p[ssl->init_num], n, 0);
    if (bytes_read <= 0) {
      ssl->rwstate = SSL_READING;
      *ok = 0;
      return bytes_read;
    }
    ssl->init_num += bytes_read;
    n -= bytes_read;
  }

  /* Feed this message into MAC computation. */
  if (hash_message == ssl_hash_message && !ssl3_hash_current_message(ssl)) {
    goto err;
  }
  if (ssl->msg_callback) {
    ssl->msg_callback(0, ssl->version, SSL3_RT_HANDSHAKE, ssl->init_buf->data,
                    (size_t)ssl->init_num + 4, ssl, ssl->msg_callback_arg);
  }
  *ok = 1;
  return ssl->init_num;

f_err:
  ssl3_send_alert(ssl, SSL3_AL_FATAL, al);

err:
  *ok = 0;
  return -1;
}
Exemplo n.º 6
0
/* Obtain handshake message of message type 'mt' (any if mt == -1),
 * maximum acceptable body length 'max'.
 * The first four bytes (msg_type and length) are read in state 'st1',
 * the body is read in state 'stn'.
 */
long ssl3_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
	{
	unsigned char *p;
	unsigned long l;
	long n;
	int i,al;

	if (s->s3->tmp.reuse_message)
		{
		s->s3->tmp.reuse_message=0;
		if ((mt >= 0) && (s->s3->tmp.message_type != mt))
			{
			al=SSL_AD_UNEXPECTED_MESSAGE;
			SSLerr(SSL_F_SSL3_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
			goto f_err;
			}
		*ok=1;
		return((int)s->s3->tmp.message_size);
		}

	p=(unsigned char *)s->init_buf->data;

	if (s->state == st1) /* s->init_num < 4 */
		{
		int skip_message;

		do
			{
			while (s->init_num < 4)
				{
				i=ssl3_read_bytes(s,SSL3_RT_HANDSHAKE,&p[s->init_num],
					4 - s->init_num, 0);
				if (i <= 0)
					{
					s->rwstate=SSL_READING;
					*ok = 0;
					return i;
					}
				s->init_num+=i;
				}
			
			skip_message = 0;
			if (!s->server)
				if (p[0] == SSL3_MT_HELLO_REQUEST)
					/* The server may always send 'Hello Request' messages --
					 * we are doing a handshake anyway now, so ignore them
					 * if their format is correct. Does not count for
					 * 'Finished' MAC. */
					if (p[1] == 0 && p[2] == 0 &&p[3] == 0)
						skip_message = 1;
			}
		while (skip_message);

		/* s->init_num == 4 */

		if ((mt >= 0) && (*p != mt))
			{
			al=SSL_AD_UNEXPECTED_MESSAGE;
			SSLerr(SSL_F_SSL3_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
			goto f_err;
			}
		if ((mt < 0) && (*p == SSL3_MT_CLIENT_HELLO) &&
					(st1 == SSL3_ST_SR_CERT_A) &&
					(stn == SSL3_ST_SR_CERT_B))
			{
			/* At this point we have got an MS SGC second client
			 * hello (maybe we should always allow the client to
			 * start a new handshake?). We need to restart the mac.
			 * Don't increment {num,total}_renegotiations because
			 * we have not completed the handshake. */
			ssl3_init_finished_mac(s);
			}

		ssl3_finish_mac(s, (unsigned char *)s->init_buf->data, 4);
			
		s->s3->tmp.message_type= *(p++);

		n2l3(p,l);
		if (l > (unsigned long)max)
			{
			al=SSL_AD_ILLEGAL_PARAMETER;
			SSLerr(SSL_F_SSL3_GET_MESSAGE,SSL_R_EXCESSIVE_MESSAGE_SIZE);
			goto f_err;
			}
		if (l && !BUF_MEM_grow(s->init_buf,(int)l))
			{
			SSLerr(SSL_F_SSL3_GET_MESSAGE,ERR_R_BUF_LIB);
			goto err;
			}
		s->s3->tmp.message_size=l;
		s->state=stn;

		s->init_num=0;
		}

	/* next state (stn) */
	p=(unsigned char *)s->init_buf->data;
	n=s->s3->tmp.message_size;
	while (n > 0)
		{
		i=ssl3_read_bytes(s,SSL3_RT_HANDSHAKE,&p[s->init_num],n,0);
		if (i <= 0)
			{
			s->rwstate=SSL_READING;
			*ok = 0;
			return i;
			}
		s->init_num += i;
		n -= i;
		}
	ssl3_finish_mac(s, (unsigned char *)s->init_buf->data, s->init_num);
	*ok=1;
	return s->init_num;
f_err:
	ssl3_send_alert(s,SSL3_AL_FATAL,al);
err:
	*ok=0;
	return(-1);
	}
Exemplo n.º 7
0
/*
 * Obtain handshake message of message type 'mt' (any if mt == -1), maximum
 * acceptable body length 'max'. The first four bytes (msg_type and length)
 * are read in state 'st1', the body is read in state 'stn'.
 */
long ssl3_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
{
    unsigned char *p;
    unsigned long l;
    long n;
    int i, al, recvd_type;

    if (s->s3->tmp.reuse_message) {
        s->s3->tmp.reuse_message = 0;
        if ((mt >= 0) && (s->s3->tmp.message_type != mt)) {
            al = SSL_AD_UNEXPECTED_MESSAGE;
            SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
            goto f_err;
        }
        *ok = 1;
        s->state = stn;
        s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
        s->init_num = (int)s->s3->tmp.message_size;
        return s->init_num;
    }

    p = (unsigned char *)s->init_buf->data;

    if (s->state == st1) {
        /* s->init_num < SSL3_HM_HEADER_LENGTH */
        int skip_message;

        do {
            while (s->init_num < SSL3_HM_HEADER_LENGTH) {
                i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type,
                    &p[s->init_num], SSL3_HM_HEADER_LENGTH - s->init_num, 0);
                if (i <= 0) {
                    s->rwstate = SSL_READING;
                    *ok = 0;
                    return i;
                }
                if (s->init_num == 0
                        && recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC
                        && (mt < 0 || mt == SSL3_MT_CHANGE_CIPHER_SPEC)) {
                    if (*p != SSL3_MT_CCS) {
                        al = SSL_AD_UNEXPECTED_MESSAGE;
                        SSLerr(SSL_F_SSL3_GET_MESSAGE,
                               SSL_R_UNEXPECTED_MESSAGE);
                        goto f_err;
                    }
                    s->init_num = i - 1;
                    s->init_msg = p + 1;
                    s->s3->tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
                    s->s3->tmp.message_size = i - 1;
                    s->state = stn;
                    *ok = 1;
                    if (s->msg_callback)
                        s->msg_callback(0, s->version,
                                        SSL3_RT_CHANGE_CIPHER_SPEC, p, 1, s,
                                        s->msg_callback_arg);
                    return i - 1;
                } else if (recvd_type != SSL3_RT_HANDSHAKE) {
                    al = SSL_AD_UNEXPECTED_MESSAGE;
                    SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_CCS_RECEIVED_EARLY);
                    goto f_err;
                }
                s->init_num += i;
            }

            skip_message = 0;
            if (!s->server)
                if (p[0] == SSL3_MT_HELLO_REQUEST)
                    /*
                     * The server may always send 'Hello Request' messages --
                     * we are doing a handshake anyway now, so ignore them if
                     * their format is correct. Does not count for 'Finished'
                     * MAC.
                     */
                    if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
                        s->init_num = 0;
                        skip_message = 1;

                        if (s->msg_callback)
                            s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
                                            p, SSL3_HM_HEADER_LENGTH, s,
                                            s->msg_callback_arg);
                    }
        } while (skip_message);
        /* s->init_num == SSL3_HM_HEADER_LENGTH */

        if ((mt >= 0) && (*p != mt)) {
            al = SSL_AD_UNEXPECTED_MESSAGE;
            SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
            goto f_err;
        }

        s->s3->tmp.message_type = *(p++);

        if(RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
            /*
             * Only happens with SSLv3+ in an SSLv2 backward compatible
             * ClientHello
             */
             /*
              * Total message size is the remaining record bytes to read
              * plus the SSL3_HM_HEADER_LENGTH bytes that we already read
              */
            l = RECORD_LAYER_get_rrec_length(&s->rlayer)
                + SSL3_HM_HEADER_LENGTH;
            if (l && !BUF_MEM_grow_clean(s->init_buf, (int)l)) {
                SSLerr(SSL_F_SSL3_GET_MESSAGE, ERR_R_BUF_LIB);
                goto err;
            }
            s->s3->tmp.message_size = l;
            s->state = stn;

            s->init_msg = s->init_buf->data;
            s->init_num = SSL3_HM_HEADER_LENGTH;
        } else {
            n2l3(p, l);
            if (l > (unsigned long)max) {
                al = SSL_AD_ILLEGAL_PARAMETER;
                SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_EXCESSIVE_MESSAGE_SIZE);
                goto f_err;
            }
            /* BUF_MEM_grow takes an 'int' parameter */
            if (l > (INT_MAX - SSL3_HM_HEADER_LENGTH)) {
                al = SSL_AD_ILLEGAL_PARAMETER;
                SSLerr(SSL_F_SSL3_GET_MESSAGE, SSL_R_EXCESSIVE_MESSAGE_SIZE);
                goto f_err;
            }
            if (l && !BUF_MEM_grow_clean(s->init_buf,
                                        (int)l + SSL3_HM_HEADER_LENGTH)) {
                SSLerr(SSL_F_SSL3_GET_MESSAGE, ERR_R_BUF_LIB);
                goto err;
            }
            s->s3->tmp.message_size = l;
            s->state = stn;

            s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
            s->init_num = 0;
        }
    }

    /* next state (stn) */
    p = s->init_msg;
    n = s->s3->tmp.message_size - s->init_num;
    while (n > 0) {
        i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
                                      &p[s->init_num], n, 0);
        if (i <= 0) {
            s->rwstate = SSL_READING;
            *ok = 0;
            return i;
        }
        s->init_num += i;
        n -= i;
    }

#ifndef OPENSSL_NO_NEXTPROTONEG
    /*
     * If receiving Finished, record MAC of prior handshake messages for
     * Finished verification.
     */
    if (*s->init_buf->data == SSL3_MT_FINISHED)
        ssl3_take_mac(s);
#endif

    /* Feed this message into MAC computation. */
    if(RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
        ssl3_finish_mac(s, (unsigned char *)s->init_buf->data, s->init_num);
        if (s->msg_callback)
            s->msg_callback(0, SSL2_VERSION, 0,  s->init_buf->data,
                            (size_t)s->init_num, s, s->msg_callback_arg);
    } else {
        ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
            s->init_num + SSL3_HM_HEADER_LENGTH);
        if (s->msg_callback)
            s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
                            (size_t)s->init_num + SSL3_HM_HEADER_LENGTH, s,
                            s->msg_callback_arg);
    }

    *ok = 1;
    return s->init_num;
 f_err:
    ssl3_send_alert(s, SSL3_AL_FATAL, al);
 err:
    *ok = 0;
    return (-1);
}