hi: Oh, I'm sorry, It is my server-side code has bugs with Twisted(16.6.0) Conch, that i have fixed it . But 'Message Authentication Code did not verify (packet #3)' error will occurs with the SecureCRT(8.0.0 or 7.3.4) client. If I connect OpenSSH_5.3p1 (or OpenSSH_6.6.1p1 ) sshd server through the SecureCRT client, it is fine. Of course， if I connect Twisted SSH server by using the Xshell client with hmac-sha2-512 options or “ssh -m hmac-sha2-512”，it is OK. I do not know if it is SecureCRT client bug or twisted problem. http://stackoverflow.com/questions/41296412/securecrt-hmac-sha2-512-message-... At 2016-12-29 01:40:07, "Craig Rodrigues" <rodrigc@crodrigues.org> wrote: Jianchen, Can you provide more details about the server you are writing? I cannot reproduce your problem with the latest Twisted code in trunk. Here is what I did: git clone https://github.com/twisted/twisted twisted-test cd twisted-test python setup.py develop cd docs/conch/examples mkdir ssh-examples ckeygen -t rsa -f ssh-keys/ssh_host_rsa_key twistd -ny demo_recvline.tac I logged in with: sshusername@127.0.0.1 -m hmac-sha2-512 -vvv -p 6022 (using username for the login, and password for the password) From the log, I saw: debug1: Authenticating to 127.0.0.1:6022 as 'username' debug3: put_host_port: [127.0.0.1]:6022 debug3: hostkeys_foreach: reading file "/Users/crodrigues/.ssh/known_hosts" debug3: record_hostkey: found key type RSA in file /Users/crodrigues/.ssh/known_hosts:5 debug3: load_hostkeys: loaded 1keys from [127.0.0.1]:6022 debug3: order_hostkeyalgs: prefer hostkeyalgs: ssh-rsa-cert-v01@openssh.com,rsa-sha2-512,rsa-sha2-256,ssh-rsa debug3: send packet: type 20 debug1: SSH2_MSG_KEXINIT sent debug3: receive packet: type 20 debug1: SSH2_MSG_KEXINIT received debug2: local client KEXINIT proposal debug2: KEX algorithms: curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,ext-info-c debug2: host key algorithms: ssh-rsa-cert-v01@openssh.com,rsa-sha2-512,rsa-sha2-256,ssh-rsa,ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,ssh-ed25519-cert-v01@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519 debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,aes192-cbc,aes256-cbc,3des-cbc debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,aes192-cbc,aes256-cbc,3des-cbc debug2: MACs ctos: hmac-sha2-512 debug2: MACs stoc: hmac-sha2-512 debug2: compression ctos: none,zlib@openssh.com,zlib debug2: compression stoc: none,zlib@openssh.com,zlib debug2: languages ctos: debug2: languages stoc: debug2: first_kex_follows 0 debug2: reserved 0 debug2: peer server KEXINIT proposal debug2: KEX algorithms: ecdh-sha2-nistp256,ecdh-sha2-nistk163,ecdh-sha2-nistp224,ecdh-sha2-nistk233,ecdh-sha2-nistb233,ecdh-sha2-nistp384,ecdh-sha2-nistk283,ecdh-sha2-nistk409,ecdh-sha2-nistb409,ecdh-sha2-nistp521,ecdh-sha2-nistt571,diffie-hellman-group1-sha1,diffie-hellman-group14-sha1 debug2: host key algorithms: ssh-rsa debug2: ciphers ctos: aes256-ctr,aes256-cbc,aes192-ctr,aes192-cbc,aes128-ctr,aes128-cbc,cast128-ctr,cast128-cbc,blowfish-cbc,3des-cbc debug2: ciphers stoc: aes256-ctr,aes256-cbc,aes192-ctr,aes192-cbc,aes128-ctr,aes128-cbc,cast128-ctr,cast128-cbc,blowfish-cbc,3des-cbc debug2: MACs ctos: hmac-sha2-512,hmac-sha2-384,hmac-sha2-256,hmac-sha1,hmac-md5 debug2: compression ctos: none,zlib debug2: compression stoc: none,zlib debug2: languages ctos: debug2: languages stoc:debug2: first_kex_follows 0 debug2: reserved 0 debug1: kex: algorithm: ecdh-sha2-nistp256 debug1: kex: host key algorithm: ssh-rsa debug1: kex: server->client cipher: aes128-ctr MAC: hmac-sha2-512 compression: none debug1: kex: client->server cipher: aes128-ctr MAC: hmac-sha2-512 compression: none debug3: send packet: type 30 debug1: sending SSH2_MSG_KEX_ECDH_INIT debug1: expecting SSH2_MSG_KEX_ECDH_REPLY debug3: receive packet: type 31 debug1: Server host key: ssh-rsa SHA256:VP7JUyzN/BuRNuCOieijGHuF9fAylDBCYYJAtJ+gDO8 debug3: put_host_port: [127.0.0.1]:6022 debug3: put_host_port: [127.0.0.1]:6022 debug3: hostkeys_foreach: reading file "/Users/crodrigues/.ssh/known_hosts" debug3: record_hostkey: found key type RSA in file /Users/crodrigues/.ssh/known_hosts:5 debug3: load_hostkeys: loaded 1keys from [127.0.0.1]:6022 debug1: Host '[127.0.0.1]:6022' is known and matches the RSA host key. debug1: Found key in /Users/crodrigues/.ssh/known_hosts:5 debug3: send packet: type 21 debug2: set_newkeys: mode 1 I did not see the problem that you saw. -- Craig On Tue, Dec 20, 2016 at 10:15 PM, 陈健 <chenjianhappy2008@126.com> wrote: hi: | | I write a SSH server with Twisted(15.5.0) Conch. But it don't support hmac-sha2-512 MAC algorithms | . However I see this problem has been fixed in https://twistedmatrix.com/trac/ticket/8108 . I asked the question in http://stackoverflow.com/questions/41254398/twisted-hmac-sha2-512-corrupted-... . Best regards, ---jianchen _______________________________________________ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python