Today I was wondering about what crypto puTTY supports and the implications for openssh support in Debian and restricting options as we've been discussing in #774711. Here is what I found:
======================================================================= puTTY -http://www.chiark.greenend.org.uk/~sgtatham/putty/ current released version 0.67 Documented at http://the.earth.li/~sgtatham/putty/0.67/htmldoc/Chapter4.html The following are supported in 0.67, described as openssh option names and for newer options the date and release they first appeared in puTTY. Keys (in sshrsa.c, sshdss.c,sshecc.c) * ssh-rsa * ssh-dss * ecdsa-sha2-nistp256, ecdsa-sha2-nistp384, ecdsa-sha2-nistp521 (2014-11-02,0.64) * ssh-ed25519 (2015-05-09, 0.65) KEX (in sshdh.c, sshecc.c) * diffie-hellman-group-exchange-sha256 * diffie-hellman-group14-sha1 * diffie-hellman-group1-sha1 * diffie-hellman-group-exchange-sha1 * ecdh-sha2-nistp256, ecdh-sha2-nistp384, ecdh-sha2-nistp521 (2014-11-02,0.64)) * [email protected] (2015-05-09, 0.65) cipher (in sshaes.c, ssharcf.c, sshblowf.h, sshdes.c, sshccp.c) * aes256-ctr, aes192-ctr, aes128-ctr * aes256-cbc, aes192-cbc, aes128-cbc * [email protected] * arcfour256, arcfour128 * blowfish-cbc(128), blowfish-ctr(256, openssh support?) * 3des-cbc, 3des-ctr(openssh support?) * [email protected] (2015-06-07, 0.65) MAC (in sshsha.c, sshsh256.c sshsh512.c, sshmd5.c, ) * hmac-md5, [email protected] * hmac-sha1, [email protected] * hmac-sha1-96, [email protected] * hmac-sha2-256, [email protected] (2013-02-20, 0.63) ======================================================================= If you want to support squeeze(released 2011-02) and newer and putty 0.63(released 2013-08) and newer (and you agree with the other decisions mentioned in this bug, like dropping rsa1/md5/des/ecdsa) then the minimum modern options you need are: ======================================================================= HostKeyAlgorithms [email protected], ssh-ed25519,\ [email protected], [email protected],ssh-rsa KexAlgorithms [email protected],\ diffie-hellman-group-exchange-sha256 Ciphers [email protected],[email protected], [email protected],aes256-ctr,aes192-ctr,aes128-ctr MACs [email protected],[email protected],\ [email protected],[email protected],\ hmac-sha2-512,hmac-sha2-256,hmac-ripemd160,[email protected] ======================================================================= If people encounter other implementations of ssh that can't communicate with a debian system using the above, please report it to #774711 as it has implicationson what debian/upstream need to support/document. HTH, -- Matt Taggart [email protected]
