<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">Hi,<div><br></div><div>This feature had been implemented in OpenSSL [1] and Chrome browser [2] for a while. Maybe, it is time to pick this request up for further discussion and review if there are resources available. What do you think?</div><div><br></div><div>Best,</div><div>Xuelei</div><div><div><br></div><div>[1]: https://github.com/openssl/openssl/issues/13597</div><div>[2]: <a href="https://chromestatus.com/feature/5696925844111360">https://chromestatus.com/feature/5696925844111360</a></div><div><br></div><div><br><blockquote type="cite"><div>On Aug 2, 2022, at 7:53 PM, Xuelei Fan <Xuelei.F@Gmail.com> wrote:</div><br class="Apple-interchange-newline"><div><meta charset="UTF-8"><blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><br class="Apple-interchange-newline">On Aug 2, 2022, at 2:55 PM, Bradford Wetmore <bradford.wetmore@oracle.com> wrote:<br><br>Hi Xuelei,<br><br>Sean wrote:<br><br><blockquote type="cite">I haven't had time to look at this in detail yet. I would like a<br>couple more weeks to review the draft.<br></blockquote><br>We've been looking closely at RFC 8879 and your proposal to add support into JSSE. I think we're in agreement that this would be a good addition for the reasons you outline.<br><br>We are currently busy with some high-priority projects so reviewing this JEP will need more time. This means that we'll need to wait a release or two for proper and thorough discussion and review. Timeline wise this is reasonable as other TLS implementations such as OpenSSL and GoLang are at a similar assessment stage [1][2].<br></blockquote><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;">Thanks for the feedback. The timeline sounds reasonable to me.</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><br>On the technical side, while having a pluggable API for supporting different/additional compression types has its merits, my preference is to have some/all of these compression types directly supported within JSSE so that this works out-of-the-box, and developers don't introduce unexpected/hard-to-debug compression errors. Otherwise everyone would have to copy the same compression code everywhere. Seems a bit painful when a simple implementation could be provided that works for many/most. The other big benefit is that this will allow for trivial backports as no API will be needed for earlier releases.<br><br></blockquote><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;">It’s fine to me to add default compression implementations, while we are keeping the flexibility for customization. I may come back for a revised design at around version 22.</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;">When more implementations start supporting this Certificate Compression RFC, I think Zlib might be the most widely used. Adding the ZLIB extension seems a natural first target as there is already an implementation in JDK, and you demonstrated how easy encoding in ZLIB is. I see Chrome already has brotli, and zstd seems like it would be a faster algorithm with tighter compression, though without prototyping, I'm not sure how much gain we'll get with smallish cert chains (i.e. 10's of kb) vs. large data sets that I've seen numbers for[3]. Patrick McManus/Fastly felt anecdotally that the difference between the three wasn't that different, compared to not having compression at all.<br><br> The TLS certificate compression specification allows any of the<br> deflate, brotli, or zstd formats for compression. Anecdotally, the<br> differences between them were very small compared to the difference<br> between compressed and uncompressed representations. [4]<br><br></blockquote><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;">I’m not sure if the performance really plays a critical role in practice. The support of compression algorithms could be an impact of interoperability (for example, work with Internet browsers such as Chrome).</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;">Thanks for the feedback!</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;">Best,</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;">Xuelei</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;">Brad<br><br>[1]<span class="Apple-converted-space"> </span><a href="https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fopenssl%2Fopenssl%2Fissues%2F13597&data=05%7C01%7Cxueleifan%40global.tencent.com%7Cc21799c52d1540bd324b08da74fa8a0a%7Ca32856f21731405cb53d480e26413adf%7C1%7C0%7C637950916681863507%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=EGu0LBAOv9KVtgP5ivRjFI9HLLelX4mIVy5raBQm0EU%3D&reserved=0">https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fopenssl%2Fopenssl%2Fissues%2F13597&data=05%7C01%7Cxueleifan%40global.tencent.com%7Cc21799c52d1540bd324b08da74fa8a0a%7Ca32856f21731405cb53d480e26413adf%7C1%7C0%7C637950916681863507%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=EGu0LBAOv9KVtgP5ivRjFI9HLLelX4mIVy5raBQm0EU%3D&reserved=0</a><br>[2]<span class="Apple-converted-space"> </span><a href="https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fgolang%2Fgo%2Fissues%2F42967&data=05%7C01%7Cxueleifan%40global.tencent.com%7Cc21799c52d1540bd324b08da74fa8a0a%7Ca32856f21731405cb53d480e26413adf%7C1%7C0%7C637950916681863507%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=eOwziZmg2Kee8KdO31pvfiXAzIxOu9plShJ11bngo2I%3D&reserved=0">https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fgolang%2Fgo%2Fissues%2F42967&data=05%7C01%7Cxueleifan%40global.tencent.com%7Cc21799c52d1540bd324b08da74fa8a0a%7Ca32856f21731405cb53d480e26413adf%7C1%7C0%7C637950916681863507%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=eOwziZmg2Kee8KdO31pvfiXAzIxOu9plShJ11bngo2I%3D&reserved=0</a><br>[3]<span class="Apple-converted-space"> </span><a href="https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Ffacebook.github.io%2Fzstd%2F&data=05%7C01%7Cxueleifan%40global.tencent.com%7Cc21799c52d1540bd324b08da74fa8a0a%7Ca32856f21731405cb53d480e26413adf%7C1%7C0%7C637950916682019740%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=TBR0haf0nGvb73pqbzcsbJlUvpSuARCSlgjUMt140As%3D&reserved=0">https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Ffacebook.github.io%2Fzstd%2F&data=05%7C01%7Cxueleifan%40global.tencent.com%7Cc21799c52d1540bd324b08da74fa8a0a%7Ca32856f21731405cb53d480e26413adf%7C1%7C0%7C637950916682019740%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=TBR0haf0nGvb73pqbzcsbJlUvpSuARCSlgjUMt140As%3D&reserved=0</a><br>[4]<span class="Apple-converted-space"> </span><a href="https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.fastly.com%2Fblog%2Fquic-handshake-tls-compression-certificates-extension-study&data=05%7C01%7Cxueleifan%40global.tencent.com%7Cc21799c52d1540bd324b08da74fa8a0a%7Ca32856f21731405cb53d480e26413adf%7C1%7C0%7C637950916682019740%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=jmMY1Y4876EvoxfU%2F0XUPUnuEN0z2466JxnQfOC%2BX7k%3D&reserved=0">https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.fastly.com%2Fblog%2Fquic-handshake-tls-compression-certificates-extension-study&data=05%7C01%7Cxueleifan%40global.tencent.com%7Cc21799c52d1540bd324b08da74fa8a0a%7Ca32856f21731405cb53d480e26413adf%7C1%7C0%7C637950916682019740%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=jmMY1Y4876EvoxfU%2F0XUPUnuEN0z2466JxnQfOC%2BX7k%3D&reserved=0</a></blockquote></div></blockquote></div><br></div></body></html>