Commit 43219695 authored by Matt Caswell's avatar Matt Caswell
Browse files

Tweak the TLSv1.3 record overflow limits 



Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2861)
parent febb0afa

include/openssl/ssl3.h

+7 −4
Original line number Diff line number Diff line
@@ -171,6 +171,7 @@ extern "C" { 
 * of padding bytes (256) plus the mac size.

 */

# define SSL3_RT_MAX_ENCRYPTED_OVERHEAD        (256 + SSL3_RT_MAX_MD_SIZE)

# define SSL3_RT_MAX_TLS13_ENCRYPTED_OVERHEAD  256



/*

 * OpenSSL currently only uses a padding length of at most one block so the
@@ -190,6 +191,8 @@ extern "C" { 
# endif

# define SSL3_RT_MAX_ENCRYPTED_LENGTH    \

            (SSL3_RT_MAX_ENCRYPTED_OVERHEAD+SSL3_RT_MAX_COMPRESSED_LENGTH)

# define SSL3_RT_MAX_TLS13_ENCRYPTED_LENGTH \

            (SSL3_RT_MAX_PLAIN_LENGTH + SSL3_RT_MAX_TLS13_ENCRYPTED_OVERHEAD)

# define SSL3_RT_MAX_PACKET_SIZE         \

            (SSL3_RT_MAX_ENCRYPTED_LENGTH+SSL3_RT_HEADER_LENGTH)

ssl/record/ssl3_record.c

+19 −7
Original line number Diff line number Diff line
@@ -340,6 +340,25 @@ int ssl3_get_record(SSL *s) 
            /* now s->rlayer.rstate == SSL_ST_READ_BODY */

        }



        if (SSL_IS_TLS13(s)) {

            if (thisrr->length > SSL3_RT_MAX_TLS13_ENCRYPTED_LENGTH) {

                al = SSL_AD_RECORD_OVERFLOW;

                SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);

                goto f_err;

            }

        } else {

            size_t len = SSL3_RT_MAX_ENCRYPTED_LENGTH;



            if (s->expand == NULL)

                len -= SSL3_RT_MAX_COMPRESSED_OVERHEAD;



            if (thisrr->length > len) {

                al = SSL_AD_RECORD_OVERFLOW;

                SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);

                goto f_err;

            }

        }



        /*

         * s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data.

         * Calculate how much more data we need to read for the rest of the
@@ -388,13 +407,6 @@ int ssl3_get_record(SSL *s) 
         * thisrr->length bytes of encrypted compressed stuff.

         */



        /* check is not needed I believe */

        if (thisrr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {

            al = SSL_AD_RECORD_OVERFLOW;

            SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);

            goto f_err;

        }



        /* decrypt in place in 'thisrr->input' */

        thisrr->data = thisrr->input;

        thisrr->orig_len = thisrr->length;