Bug 1281705 - Bad cipher 'blowfish'
Summary: Bad cipher 'blowfish'
Keywords:
Status: CLOSED NOTABUG
Alias: None
Product: Fedora
Classification: Fedora
Component: openssh
Version: 23
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Jakub Jelen
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2015-11-13 08:06 UTC by Vratislav Podzimek
Modified: 2016-02-08 10:07 UTC (History)
5 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2015-12-23 09:08:45 UTC
Type: Bug
Embargoed:


Attachments (Terms of Use)

Description Vratislav Podzimek 2015-11-13 08:06:50 UTC
Description of problem:
If I have the 'blowfish' cipher specified in my ~/.ssh/config file, I cannot ssh to any machine because ssh complains about it being a bad cipher (whatever that wording means).

Version-Release number of selected component (if applicable):
openssh-7.1p1-5.fc23.x86_64

How reproducible:
100%

Steps to Reproduce:
1. specify 'Cipher blowfish' for some of Host in ~/.ssh/config
2. try to ssh somewhere

Actual results:
line XY: Bad cipher 'blowfish'.

Expected results:
ssh login successful

Additional info:
'blowfish-cbc' works, but since people tend to use their ssh configs for years, I think ssh should do the change on its own internally and possibly just produce some warning.

Comment 1 Jakub Jelen 2015-12-11 14:24:59 UTC
Sorry for a late answer. I missed this bug somehow.

If you check the manual page for ssh_config(5), you will read:

> Cipher   Specifies the cipher to use for encrypting the session in protocol version 1.

This explains it. This option has nothing to do in current setups and has no effect for protocol SSHv2.


From my opinion, it should rather yell about unsupported option, since SSHv1 is gone in version 7+. This is only thing we can fix. Maintaining compatible options for many years obsolete protocol is not a good idea.

Comment 2 Vratislav Podzimek 2016-02-08 10:07:41 UTC
(In reply to Jakub Jelen from comment #1)
> Sorry for a late answer. I missed this bug somehow.
> 
> If you check the manual page for ssh_config(5), you will read:
> 
> > Cipher   Specifies the cipher to use for encrypting the session in protocol version 1.
> 
> This explains it. This option has nothing to do in current setups and has no
> effect for protocol SSHv2.
> 
> 
> From my opinion, it should rather yell about unsupported option, since SSHv1
> is gone in version 7+. This is only thing we can fix. Maintaining compatible
> options for many years obsolete protocol is not a good idea.

Fair enough, thanks for the explanation.


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