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martin

Re: ECDH key exchange missing from SSH options

2021-09-01

ECDSA/ECDH is supported since WinSCP 5.8.1:
Issue 1390 – Support for ECDSA keys

meddler

Re: Fixed

2017-11-30 02:55

May I ask what the server side issue causing the protocol error was?

andyseubert

Fixed

2016-03-16 21:39

Turns out the problem was with the server side.

Sorry for any distraction from real problems or issues!

andyseubert

more details

2016-03-16 20:17

Maybe I didn't include enough details to receive support:
Version of WinSCP: 5.7.7 build 6257
Version of Windows: tested on Windows 10, Windows server 2008, Windows Vista
Mode: GUI mode not scripting
Protocol: SFTP and SCP

Reproduction steps: simply trying to connect.

Odd situation: the server is a custom implementation of "mavericks" sshtools library version 1.6.16
https://jadaptive.com/en/products/java-ssh-server

The issue only arose after the server side disabled the key exchange version KEX_DIFFIE_HELLMAN_GROUP1_SHA1 to guard against the logjam vulnerability

LOG:

. 2016-03-15 15:59:18.319 --------------------------------------------------------------------------
. 2016-03-15 15:59:18.319 WinSCP Version 5.7.7 (Build 6257) (OS 10.0.10586 - Windows 10 Pro)
. 2016-03-15 15:59:18.319 Configuration: HKCU\Software\Martin Prikryl\WinSCP 2\
. 2016-03-15 15:59:18.319 Log level: Debug 2
. 2016-03-15 15:59:18.319 Local account: EVIL_EMPIRE\andys
. 2016-03-15 15:59:18.319 Working directory: C:\Program Files (x86)\WinSCP
. 2016-03-15 15:59:18.319 Process ID: 18948
. 2016-03-15 15:59:18.319 Command-line: "C:\Program Files (x86)\WinSCP\WinSCP.exe" 
. 2016-03-15 15:59:18.319 Time zone: Current: GMT-7, Standard: GMT-8 (Pacific Standard Time), DST: GMT-7 (Pacific Daylight Time), DST Start: 3/13/2016, DST End: 11/6/2016
. 2016-03-15 15:59:18.319 Login time: Tuesday, March 15, 2016 3:59:18 PM
. 2016-03-15 15:59:18.319 --------------------------------------------------------------------------
. 2016-03-15 15:59:18.319 Session name: andyseub@devel-v8.unival.com (Modified site)
. 2016-03-15 15:59:18.319 Host name: devel-v8.unival.com (Port: 2222)
. 2016-03-15 15:59:18.319 User name: andys (Password: Yes, Key file: No)
. 2016-03-15 15:59:18.319 Tunnel: No
. 2016-03-15 15:59:18.319 Transfer Protocol: SCP
. 2016-03-15 15:59:18.319 Ping type: -, Ping interval: 30 sec; Timeout: 15 sec
. 2016-03-15 15:59:18.319 Disable Nagle: No
. 2016-03-15 15:59:18.319 Proxy: none
. 2016-03-15 15:59:18.320 Send buffer: 262144
. 2016-03-15 15:59:18.320 SSH protocol version: 2; Compression: No
. 2016-03-15 15:59:18.320 Bypass authentication: No
. 2016-03-15 15:59:18.320 Try agent: Yes; Agent forwarding: No; TIS/CryptoCard: No; KI: Yes; GSSAPI: No
. 2016-03-15 15:59:18.320 Ciphers: aes,blowfish,3des,WARN,arcfour,des; Ssh2DES: No
. 2016-03-15 15:59:18.320 KEX: dh-gex-sha1,dh-group14-sha1,rsa,WARN,dh-group1-sha1
. 2016-03-15 15:59:18.320 SSH Bugs: A,A,A,A,A,A,A,A,A,A,A,A
. 2016-03-15 15:59:18.320 Simple channel: Yes
. 2016-03-15 15:59:18.320 Return code variable: Autodetect; Lookup user groups: A
. 2016-03-15 15:59:18.320 Shell: default
. 2016-03-15 15:59:18.320 EOL: 0, UTF: 2
. 2016-03-15 15:59:18.320 Clear aliases: Yes, Unset nat.vars: Yes, Resolve symlinks: Yes
. 2016-03-15 15:59:18.320 LS: ls -la, Ign LS warn: Yes, Scp1 Comp: No
. 2016-03-15 15:59:18.320 Local directory: default, Remote directory: home, Update: Yes, Cache: Yes
. 2016-03-15 15:59:18.320 Cache directory changes: Yes, Permanent: Yes
. 2016-03-15 15:59:18.320 DST mode: 1;Timezone offset: 0h 0m
. 2016-03-15 15:59:18.320 --------------------------------------------------------------------------
. 2016-03-15 15:59:18.456 Looking up host "devel-v8.unival.com"
. 2016-03-15 15:59:18.469 Connecting to 10.1.10.42 port 2222
. 2016-03-15 15:59:18.471 Selecting events 63 for socket 1348
. 2016-03-15 15:59:18.509 Waiting for the server to continue with the initialization
. 2016-03-15 15:59:18.509 Looking for incoming data
. 2016-03-15 15:59:18.509 Looking for network events
. 2016-03-15 15:59:18.509 Detected network event
. 2016-03-15 15:59:18.509 Enumerating network events for socket 1348
. 2016-03-15 15:59:18.509 Enumerated 19 network events making 19 cumulative events for socket 1348
. 2016-03-15 15:59:18.509 Handling network read event on socket 1348 with error 0
. 2016-03-15 15:59:18.509 Server version: SSH-2.0-Maverick_SSHD
. 2016-03-15 15:59:18.509 Using SSH protocol version 2
. 2016-03-15 15:59:18.509 We claim version: SSH-2.0-WinSCP_release_5.7.7
. 2016-03-15 15:59:18.509 Handling network write event on socket 1348 with error 0
. 2016-03-15 15:59:18.509 Handling network connect event on socket 1348 with error 0
. 2016-03-15 15:59:18.509 Waiting for the server to continue with the initialization
. 2016-03-15 15:59:18.509 Looking for incoming data
. 2016-03-15 15:59:18.509 Looking for network events
. 2016-03-15 15:59:18.511 Detected network event
. 2016-03-15 15:59:18.511 Enumerating network events for socket 1348
. 2016-03-15 15:59:18.511 Enumerated 1 network events making 1 cumulative events for socket 1348
. 2016-03-15 15:59:18.511 Handling network read event on socket 1348 with error 0
. 2016-03-15 15:59:18.512 Doing Diffie-Hellman group exchange
. 2016-03-15 15:59:18.512 Waiting for the server to continue with the initialization
. 2016-03-15 15:59:18.512 Looking for incoming data
. 2016-03-15 15:59:18.512 Looking for network events
. 2016-03-15 15:59:18.513 Detected network event
. 2016-03-15 15:59:18.513 Enumerating network events for socket 1348
. 2016-03-15 15:59:18.513 Enumerated 1 network events making 1 cumulative events for socket 1348
. 2016-03-15 15:59:18.513 Handling network read event on socket 1348 with error 0
. 2016-03-15 15:59:18.513 Doing Diffie-Hellman key exchange with hash SHA-256
. 2016-03-15 15:59:18.887 Waiting for the server to continue with the initialization
. 2016-03-15 15:59:18.887 Looking for incoming data
. 2016-03-15 15:59:18.887 Looking for network events
. 2016-03-15 15:59:18.887 Detected network event
. 2016-03-15 15:59:18.887 Enumerating network events for socket 1348
. 2016-03-15 15:59:18.887 Enumerated 33 network events making 33 cumulative events for socket 1348
. 2016-03-15 15:59:18.887 Handling network read event on socket 1348 with error 0
. 2016-03-15 15:59:18.887 Received disconnect message (protocol error)
. 2016-03-15 15:59:18.887 Disconnection message text: Failed to read binary packet data!
. 2016-03-15 15:59:18.887 Selecting events 0 for socket 1348
. 2016-03-15 15:59:18.887 Server sent disconnect message
. 2016-03-15 15:59:18.887 type 2 (protocol error):
. 2016-03-15 15:59:18.887 "Failed to read binary packet data!"
* 2016-03-15 15:59:18.931 (EFatal) Server sent disconnect message
* 2016-03-15 15:59:18.931 type 2 (protocol error):
* 2016-03-15 15:59:18.931 "Failed to read binary packet data!"

andyseubert

Settings screen showing missing ECDH

2016-03-15 19:03

Attached here is a screenshot if that's helpful.

Guest

ECDH key exchange missing from SSH options

2016-03-15 18:53

From the Advanced, SSH > Key exchange dialog, the Elliptic Curve Key exchange is not listed as an option.
I don't know if this is related, but I suspect that it is..

I am receiving the error