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<p class="MsoNormal"><span lang="IT">Hi,<o:p></o:p></span></p>
<p class="MsoNormal">recently we moved from gnults 2.13.23 to gnutls 3.6.5.<o:p></o:p></p>
<p class="MsoNormal">By doing this I encountered an issue with applications using the library. In fact it happens that the our TR-069 agent is sending pkts over https by means of gnutls_record_send. It might happens that gnutls_record_send is called with data_size=0.
This was accepted in the older gnutls 2.13.23.<o:p></o:p></p>
<p class="MsoNormal">With gnutls 3.6.5 it is not. In fact gnutls_record_send calls gnutls_record_send2 with pad=0, and subsequently _gnutls_send_tlen_int that verifies that if both data_size and pad are 0 returns GNUTLS_E_INVALID_REQUEST (record.c line 492).
<o:p></o:p></p>
<p class="MsoNormal">I tried to modify the application to add a padding>=1 in case of data_size=0 by calling gnutls_record_can_use_length_hiding. In fact even if this function was returning 1, the subsequent call of gnutls_record_send2 was still returning
GNUTLS_E_INVALID_REQUEST. In fact the discrimination was that tls1.3 handshake semantics was set to false. That is a bit misleading, IMHO. <o:p></o:p></p>
<p class="MsoNormal">Can you explain the reason for that?<o:p></o:p></p>
<p class="MsoNormal">Moreover why this restriction on the data_size length has been added to?<o:p></o:p></p>
<p class="MsoNormal">Thanks<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Andrea<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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