Commit 93f528f3 authored by Matt Caswell's avatar Matt Caswell
Browse files

Auto retry if we ditch records during shutdown 



If we've sent a close_notify and we're waiting for one back we drop
incoming records until we see the close_notify we're looking for. If
SSL_MODE_AUTO_RETRY is on, then we should immediately try and read the
next record.

Fixes #6262

Reviewed-by: default avatarBernd Edlinger <bernd.edlinger@hotmail.de>
Reviewed-by: default avatarKurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/6340)
parent c7504aeb

ssl/record/rec_layer_s3.c

+43 −36
Original line number Diff line number Diff line
@@ -1457,40 +1457,6 @@ int ssl3_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf, 
        return -1;

    }



    /*

     * In case of record types for which we have 'fragment' storage, fill

     * that so that we can process the data at a fixed place.

     */

    {

        size_t dest_maxlen = 0;

        unsigned char *dest = NULL;

        size_t *dest_len = NULL;



        if (SSL3_RECORD_get_type(rr) == SSL3_RT_HANDSHAKE) {

            dest_maxlen = sizeof(s->rlayer.handshake_fragment);

            dest = s->rlayer.handshake_fragment;

            dest_len = &s->rlayer.handshake_fragment_len;

        }



        if (dest_maxlen > 0) {

            n = dest_maxlen - *dest_len; /* available space in 'dest' */

            if (SSL3_RECORD_get_length(rr) < n)

                n = SSL3_RECORD_get_length(rr); /* available bytes */



            /* now move 'n' bytes: */

            memcpy(dest + *dest_len,

                   SSL3_RECORD_get_data(rr) + SSL3_RECORD_get_off(rr), n);

            SSL3_RECORD_add_off(rr, n);

            SSL3_RECORD_sub_length(rr, n);

            *dest_len += n;

            if (SSL3_RECORD_get_length(rr) == 0)

                SSL3_RECORD_set_read(rr);



            if (*dest_len < dest_maxlen)

                goto start;     /* fragment was too small */

        }

    }



    /*-

     * s->rlayer.handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;

     * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
@@ -1583,14 +1549,55 @@ int ssl3_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf, 
        return -1;

    }



    if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a

                                            * shutdown */

    /*

     * If we've sent a close_notify but not yet received one back then ditch

     * anything we read.

     */

    if ((s->shutdown & SSL_SENT_SHUTDOWN) != 0 ) {

        /*

         * In TLSv1.3 this could get problematic if we receive a KeyUpdate

         * message after we sent a close_notify because we're about to ditch it,

         * so we won't be able to read a close_notify sent afterwards! We don't

         * support that.

         */

        s->rwstate = SSL_NOTHING;

        SSL3_RECORD_set_length(rr, 0);

        SSL3_RECORD_set_read(rr);



        if (SSL3_RECORD_get_type(rr) == SSL3_RT_HANDSHAKE

                && (s->mode & SSL_MODE_AUTO_RETRY) != 0)

            goto start;

        return 0;

    }



    /*

     * For handshake data we have 'fragment' storage, so fill that so that we

     * can process the header at a fixed place. This is done after the

     * "SHUTDOWN" code above to avoid filling the fragment storage with data

     * that we're just going to discard.

     */

    if (SSL3_RECORD_get_type(rr) == SSL3_RT_HANDSHAKE) {

        size_t dest_maxlen = sizeof(s->rlayer.handshake_fragment);

        unsigned char *dest = s->rlayer.handshake_fragment;

        size_t *dest_len = &s->rlayer.handshake_fragment_len;



        n = dest_maxlen - *dest_len; /* available space in 'dest' */

        if (SSL3_RECORD_get_length(rr) < n)

            n = SSL3_RECORD_get_length(rr); /* available bytes */



        /* now move 'n' bytes: */

        memcpy(dest + *dest_len,

               SSL3_RECORD_get_data(rr) + SSL3_RECORD_get_off(rr), n);

        SSL3_RECORD_add_off(rr, n);

        SSL3_RECORD_sub_length(rr, n);

        *dest_len += n;

        if (SSL3_RECORD_get_length(rr) == 0)

            SSL3_RECORD_set_read(rr);



        if (*dest_len < dest_maxlen)

            goto start;     /* fragment was too small */

    }



    if (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC) {

        SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_READ_BYTES,

                 SSL_R_CCS_RECEIVED_EARLY);