<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class=""><blockquote type="cite" class=""><div dir="ltr" class=""><div class="">What kind of padding length customization would you like to see in the JDK?</div></div></blockquote></div><div class=""><div dir="ltr" class=""><div class=""><br class=""></div></div></div><div class="">I may be hesitate to add a new API. A default random padding could be used instead, and might be controlled with a system property (e.g, “jdk.tls.client/server.maxRecordPadding” or “jdk.tls.client/server.recordPaddingRange”). If random padding is enable, the padding adding/removing should be constant-time.</div><div class=""><br class=""></div><div class="">Xuelei </div><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Nov 7, 2022, at 6:21 AM, Daniel Jeliński <<a href="mailto:djelinski1@gmail.com" class="">djelinski1@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class="">Thanks Xuelei and Brad for your replies!<div class=""><br class=""></div><div class=""><a href="https://bugs.openjdk.org/browse/JDK-8244983" class="">https://bugs.openjdk.org/browse/JDK-8244983</a> mentions that random padding could be used to mitigate BREACH attack. I googled for "breach random padding", found 3 similar requests [1] [2] [3] for enhancements, none of them was implemented. Also <a href="https://www.breachattack.com/" class="">https://www.breachattack.com/</a> does not list TLS record padding as a means to mitigate the attack, presumably because even with random padding the response length will be eventually revealed if the request can be repeated.<br class=""></div><div class=""><br class=""></div><div class="">What kind of padding length customization would you like to see in the JDK?</div><div class=""><br class=""></div><div class="">Daniel</div><div class=""><br class=""></div><div class="">[1] <a href="https://www.drupal.org/project/seckit/issues/2737783" class="">https://www.drupal.org/project/seckit/issues/2737783</a></div><div class="">[2] <a href="https://bz.apache.org/bugzilla/show_bug.cgi?id=64434" class="">https://bz.apache.org/bugzilla/show_bug.cgi?id=64434</a></div><div class="">[3] <a href="https://trac.nginx.org/nginx/ticket/1977" class="">https://trac.nginx.org/nginx/ticket/1977</a></div><div class=""><br class=""></div></div><br class=""><div class="gmail_quote"><div dir="ltr" class="gmail_attr">sob., 5 lis 2022 o 04:01 Bradford Wetmore <<a href="mailto:bradford.wetmore@oracle.com" class="">bradford.wetmore@oracle.com</a>> napisał(a):<br class=""></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br class="">
<br class="">
On 11/4/2022 8:58 AM, Xuelei Fan wrote:<br class="">
> The padding may be also necessary to prevent from a kind of attacks, <br class="">
> besides hiding the length. But I cannot recall the details.<br class="">
<br class="">
I have a vague recollection of that, but I was thinking it was something <br class="">
pre-1.3. But I'm not seeing any special padding in the pre-TLSv1.3 <br class="">
changeset:<br class="">
<br class="">
c7c819cd8bba9f204f23b24a0d788fda61823eb3<br class="">
<br class="">
so I may be off in my recollections.<br class="">
<br class="">
> Here is an enhancement <br class="">
> request in JBS (<a href="https://bugs.openjdk.org/browse/JDK-8244983" rel="noreferrer" target="_blank" class="">https://bugs.openjdk.org/browse/JDK-8244983</a> <br class="">
> <<a href="https://bugs.openjdk.org/browse/JDK-8244983" rel="noreferrer" target="_blank" class="">https://bugs.openjdk.org/browse/JDK-8244983</a>>), please feel free to take <br class="">
> it.<br class="">
<br class="">
Ah yes.<br class="">
<br class="">
Brad<br class="">
<br class="">
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