[CentOS] signing RPM packages with SHA256

Alice Wonder alice at domblogger.net
Thu Jan 21 03:28:56 UTC 2016


On 01/20/2016 03:32 PM, Alice Wonder wrote:
> On 01/20/2016 02:58 AM, Johnny Hughes wrote:
>> On 01/20/2016 04:52 AM, Johnny Hughes wrote:
>>> On 01/20/2016 04:48 AM, Johnny Hughes wrote:
>>>> On 01/20/2016 04:39 AM, Johnny Hughes wrote:
>>>>> On 01/20/2016 01:37 AM, Alice Wonder wrote:
>>>>>> hi,
>>>>>>
>>>>>> I noticed that RPM packages I sign use SHA1
>>>>>>
>>>>>> Signature   : RSA/SHA1, Fri 08 Jan 2016 10:50:58 AM PST, Key ID
>>>>>> ad3b591d147abf59
>>>>>>
>>>>>> Signatures from CentOS 7 use SHA256
>>>>>>
>>>>>> Signature   : RSA/SHA256, Wed 06 Jan 2016 08:54:58 AM PST, Key ID
>>>>>> 24c6a8a7f4a80eb5
>>>>>>
>>>>>> I'm trying to find where / how to use sha256 when I sign packages
>>>>>> but I
>>>>>> am not having much luck. Closest I have found is this :
>>>>>>
>>>>>> https://fedoraproject.org/wiki/RPM_file_format_changes_to_support_SHA-256
>>>>>>
>>>>>>
>>>>>> That page appears to be from 2009 and six years is a really long
>>>>>> time,
>>>>>> things change a lot.
>>>>>>
>>>>>> Is there an up to date reference somewhere on RPM package signing
>>>>>> that I
>>>>>> haven't stumbled upon yet?
>>>>>>
>>>>>> SHA1 is broken. I shouldn't be using it.
>>>>>>
>>>>>> CentOS 7 is all I build packages for.
>>>>>>
>>>>>
>>>>> In your .rpmmacros file .. try setting:
>>>>>
>>>>> _binary_filedigest_algorithm SHA256
>>>>>
>>>>> or from the command line:
>>>>>
>>>>> rpm --define '_binary_filedigest_algorithm SHA256' <current_line>
>>>>>
>>>>> =====
>>>>>
>>>>> if some some reason it does not like the SAH256 value .. try 8
>>>>> instead.  So:
>>>>>
>>>>> rpm --define '_binary_filedigest_algorithm 8'
>>>>>
>>>>> or in .rpmmacros:
>>>>>
>>>>> _binary_filedigest_algorithm 8
>>>>>
>>>>
>>>> There is another one as well:
>>>>
>>>> --define "_source_filedigest_algorithm 8"
>>>>
>>>> --define "_binary_filedigest_algorithm 8"
>>>>
>>>>
>>>> Defining it in the .rpmmacros would be best .. I think otherwise you
>>>> would need to define it in youe rpmbild line AND your rpm signature
>>>> line.
>>>>
>>>> Are you building your rpms in mock or from rpmbuild on the command
>>>> line?
>>>>
>>>> If I do this on my default c7 install, I get that as the default:
>>>>
>>>> [jhughes at localhost ~]$ rpmbuild --showrc | grep filedigest_algorithm
>>>> -14: _binary_filedigest_algorithm    8
>>>> -14: _source_filedigest_algorithm    8
>>>>
>>>> Not sure how you got it to do it in SHA1 :)
>>>
>>> One last thought .. are you using something like:
>>>
>>> --force-v3-sigs
>>>
>>> in your signing command line?
>>
>> If you are building in mock .. you would do it like this int he mock
>> config with the other variables:
>>
>> config_opts['macros']['%_binary_filedigest_algorithm'] = "8"
>> config_opts['macros']['%_source_filedigest_algorithm'] = "8"
>>
>> But again, building on a c7 machine, it should be the default.
>>
>>
>>
>> _______________________________________________
>> CentOS mailing list
>> CentOS at centos.org
>> https://lists.centos.org/mailman/listinfo/centos
>>
>
> I'm still not getting it to work - I am trying outside of mock.
>
> %_signature gpg
> %_binary_filedigest_algorithm 8
> %_gpg_name Alice Wonder Miscreations
>
> represents my current .rpmmacros
>
> Before just _signature_gpg and _gpg_name were defined
>
> rpm --showrc |grep filedigest
> -14: _binary_filedigest_algorithm    8
> -14: _source_filedigest_algorithm    8
>
> (it has that value whether or not I define the
> _binary_filedigest_algorithm in my .rpmmacros)
>
> I wonder if I might be missing something?
>
> The  --verbose switch to rpm when I use --addsign doesn't give any
> additional output.
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> https://lists.centos.org/mailman/listinfo/centos

This is interesting -

ls -al .gnupg/
total 40
drwxrwxr-x.  2 alice alice  4096 Jan 20 11:05 .
drwx------. 91 alice alice 12288 Jan 20 15:28 ..
-rw-------   1 alice alice  3501 Jan 20 11:05 pubring.gpg
-rw-------   1 alice alice  3501 Jan 20 11:05 pubring.gpg~
-rw-------.  1 alice alice   600 Jan 20 11:05 random_seed
-rw-------   1 alice alice  7537 Jan 20 11:05 secring.gpg
-rw-------.  1 alice alice  1360 Jan 20 11:05 trustdb.gpg

There is no gpg.conf in there, or in my home directory, it seems I only 
have a gpg.conf in old home directories from previous versions (I always 
start fresh but restore old /home as /home-old)

I don't see a gpg.conf in /etc/skel either and yum provides doesn't 
indicate any package provides /etc/skel/gpg.conf or 
/etc/skel/.gnupg/gpg.conf

I am wondering if my issue is related to my gpg configuration but I 
don't even know where the hell the user specific configuration is kept now.

/etc/gnupg for system-wide configuration exists but is empty.

No idea if the gpg configuration could be the issue, and the gpg2 man 
page doesn't seem to indicate where the configuration file is kept now. 
It does reference a gpg.conf-2 but that file doesn't exist either.

What's kind of sad, every single RPM signing howto I can find does not 
address the SHA1/SHA256 issue and when they do show the signature, it's 
always SHA1. Of course it is mostly very old.

Is there modern documentation to RPM anywhere?



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