Bug 2424 - Compatibility for iSSH and Ubuntu/Mint Putty
Summary: Compatibility for iSSH and Ubuntu/Mint Putty
Status: CLOSED FIXED
Alias: None
Product: Portable OpenSSH
Classification: Unclassified
Component: sshd (show other bugs)
Version: 6.9p1
Hardware: Other Linux
: P5 enhancement
Assignee: Darren Tucker
URL:
Keywords:
Depends on:
Blocks: V_7_0
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Reported: 2015-07-05 23:09 AEST by Jay Rouman
Modified: 2016-08-02 10:42 AEST (History)
1 user (show)

See Also:

Attachments
Add old PuTTY dev versions to the DH-GEX blacklist. (696 bytes, patch)
2015-07-10 13:41 AEST, Darren Tucker 		no flags Details | Diff
iSSH compatibility patch (536 bytes, patch)
2015-07-12 00:16 AEST, Jay Rouman 		no flags Details | Diff
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Description Jay Rouman 2015-07-05 23:09:09 AEST 
Please consider adding "PuTTY_Local*" to the PuTTY versions allowed to use SSH_OLD_DHGEX in compat.c.  This is the ID for iSSH and the PuTTY distributed with Ubuntu and Mint Linux.  Sadly, iSSH is no longer being maintained so a fix on that end is unlikely.
Comment 1 Darren Tucker 2015-07-06 10:13:45 AEST 
I did actually consider doing that when I implemented the change.

I decided against it because it means that modern development versions of PuTTY would also be impacted, and I'd rather new PuTTYs work with as much of OpenSSH as possible, even if that means older development snapshots.

Looking at it again, my putty git tree identifies itself as SSH-2.0-PuTTY_Unidentified_Local_Build not PuTTY_Local.*.  Is the latter identifier used for versions built from development trees or something else?
Comment 2 Jay Rouman 2015-07-06 11:05:15 AEST 
iSSH is an Apple iOS app that is built on some version of Putty.  The developer has moved on but it is still available in the App Store for people who have already purchased it.

It identifies to ssh as:

debug1: Client protocol version 2.0; client software version PuTTY_Local:_Oct_19_2013_01:34:44


When you type "apt-get install putty" in Mint, you get a version of Putty that says "Unidentified build, June 23, 2015 11:44:03" and identifies to ssh as:

debug1: Client protocol version 2.0; client software version PuTTY_Local:_Jun_23_2015_11:44:03

I don't know anything about how these version of Putty were created.
Comment 3 Darren Tucker 2015-07-09 21:48:22 AEST 
I've checked with the PuTTY folks and according to Simon Tatham, PuTTY_Local.* "was a prefix used in the old versioning system,
before I reworked it all prior to our migration from svn to git (as of
r10262, aka 4d8782e74fed043fdf549718f99494622fe9e79b)" in September 2014 and that it is probably safe to assume any client using it doesn't do RFC4419 DH-GEX.
Comment 4 Darren Tucker 2015-07-10 13:41:57 AEST 
Created attachment 2662 [details]
Add old PuTTY dev versions to the DH-GEX blacklist.

Please try this patch and let me know if it works.
Comment 5 Jay Rouman 2015-07-12 00:16:17 AEST 
Created attachment 2663 [details]
iSSH compatibility patch
Comment 6 Jay Rouman 2015-07-12 00:19:28 AEST 
I am traveling and don't have access to a test machine but your patch is essentially what works on iSSH for me.  I have attached my patch which I probably should have included originally.  I am sure what you did will work fine.
Comment 7 Darren Tucker 2015-07-13 14:58:07 AEST 
Patch committed and will be in the 7.0 release.  Thanks.
Comment 8 Damien Miller 2016-08-02 10:42:54 AEST 
Close all resolved bugs after 7.3p1 release