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</o:shapelayout></xml><![endif]--></head><body lang=RU link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span lang=EN-US style='color:#1F497D'>Hello,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'>Previous patch adds regression: dbclient throws error "Sorry, I won't let you use password auth unencrypted." with Chacha20-Poly1305 negotiated despite the fact encryption is here.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'>Please refer fixed version attached, <a href="https://github.com/mkj/dropbear/pull/93">https://github.com/mkj/dropbear/pull/93</a> is also updated.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'><o:p> </o:p></span></p><div><p class=MsoNormal><span lang=EN-US style='font-size:9.0pt;font-family:"Arial Narrow",sans-serif;color:#1F497D;mso-fareast-language:RU'>Best Regards, Vladislav Grishenko</span><span lang=EN-US style='font-size:9.0pt;color:#1F497D;mso-fareast-language:RU'><o:p></o:p></span></p></div><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span style='mso-fareast-language:RU'>From:</span></b><span style='mso-fareast-language:RU'> Vladislav Grishenko <themiron.ru@gmail.com> <br><b>Sent:</b> Sunday, April 26, 2020 5:49 AM<br><b>To:</b> dropbear@ucc.asn.au<br><b>Cc:</b> 'Matt Johnston' <matt@ucc.asn.au><br><b>Subject:</b> [PATCH] Add Chacha20-Poly1305 and AES-GCM ciphers<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=EN-US>Hello,<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=EN-US>Chacha20-Poly1305 an AES-GCM are authenticated encryption ciphers, widely supported by multiple ssh servers and clients.<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo2'><![if !supportLists]><span lang=EN-US style='font-family:Symbol'><span style='mso-list:Ignore'>·<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span lang=EN-US>Chacha20-Poly1305 is faster than AES256 on CPU w/o dedicated AES instructions, having the same key size.<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo2'><![if !supportLists]><span lang=EN-US style='font-family:Symbol'><span style='mso-list:Ignore'>·<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span lang=EN-US>AES-GCM is combination of AES CTR mode and GHASH, slower than AES-CTR on CPU w/o dedicated AES/GHASH instructions.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Since LibTomCrypt has no AES/GHASH acceleration support (AES-NI/ARM AES/etc), AES-GCM is disabled by default, Chacha20-Poly1305 gets the highest prio.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Transferring 256Gb local file with scp on x86_64:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>3des-cbc: 16.8MB/s<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>aes128-cbc: 57.1MB/s<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>aes256-cbc: 52.1MB/s<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>aes128-ctr: 56.8MB/s<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>aes256-ctr: 51.7MB/s<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><a href="mailto:aes128-gcm@openssh.com">aes128-gcm@openssh.com</a>: 42.1MB/s<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><a href="mailto:aes256-gcm@openssh.com">aes256-gcm@openssh.com</a>: 39.0MB/s<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><a href="mailto:chacha20-poly1305@openssh.com">chacha20-poly1305@openssh.com</a>: 105.2MB/s<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>As seen, Chacha20-Poly1305 is ~two times faster than aes-ctr, aes-gcm highly relies on ghash therefore slower (or maybe LibTomCrypt approach is not really optimal).<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>So far, DROPBEAR_CHACHA20POLY1305 increases dropbear binary by ~5,5Kb on X86-64, DROPBEAR_ENABLE_GCM_MODE – by ~6kB, using LibTomCrypt routines.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Related PR against current sources is here </span><a href="https://github.com/mkj/dropbear/pull/93"><span lang=EN-US style='color:windowtext'>https://github.com/mkj/dropbear/pull/93</span></a><span lang=EN-US><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Also, current sources does not allow CBC & CTR modes to be fully disabled, resulting in build errors.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Independent PR against current sources is here </span><a href="https://github.com/mkj/dropbear/pull/95"><span lang=EN-US style='color:windowtext'>https://github.com/mkj/dropbear/pull/95</span></a><span lang=EN-US><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>If both patches are applied, newly introduced sysoptions.h check needs to be enhanced with DROPBEAR_AEAD_MODE as well, I can’t make PR because it makes no sense unless both things are there.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>In text form it will be just:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>-#if !(DROPBEAR_ENABLE_CBC_MODE || DROPBEAR_ENABLE_CTR_MODE)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>+#if !(DROPBEAR_ENABLE_CBC_MODE || DROPBEAR_ENABLE_CTR_MODE || DROPBEAR_AEAD_MODE)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Review and/or any suggestios will be highly appreciated.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:9.0pt;font-family:"Arial Narrow",sans-serif;mso-fareast-language:RU'>Thank you and<o:p></o:p></span></p><p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US style='font-size:9.0pt;font-family:"Arial Narrow",sans-serif;mso-fareast-language:RU'>Best Regards, Vladislav Grishenko<span style='color:#1F497D'><o:p></o:p></span></span></p></div></body></html>