Blowfish hashed passwords
KT Walrus
kevin at my.walr.us
Mon Jun 6 13:36:51 UTC 2016
> Changing your php app will probably be the easiest solution.
Since I’m using Docker, the easiest solution for me is to find a linux distro that can run Dovecot well and supports BLF-CRYPT as well.
What Linux distros support BLF-CRYPT and are well tested and secure?
> On Jun 5, 2016, at 8:54 PM, Edgar Pettijohn <edgar at pettijohn-web.com> wrote:
>
> On 16-06-05 20:36:35, KT Walrus wrote:
>>>> Maybe, Dovecot could just add support for BLF-CRYPT by using the open source implementation of Blowfish hashing found in https://github.com/php/php-src/tree/master/ext/standard <https://github.com/php/php-src/tree/master/ext/standard>. The implementation looks like a single function to generate the hash. I???m not much of a programmer, but it would seem to me that these .c/.h files could be added to Dovecot for doing BLF-CRYPT hashing.
>>>>
>>> It already does. As previously stated.
>>
>> It doesn???t for me. I???m building Dovecot from source (v2.2.24) in a Docker container using Ubuntu 14.04.
>>
>> Does BLF-CRYPT work for you?
>
> Yes, but I don't use ubuntu.
>
>>
>> Maybe I???m not building Dovecot correctly. I install libssl-dev and libmysqlclient-dev and do:
>>
>> $ ./configure --prefix=/usr --sysconfdir=/etc --with-mysql
>> $ make
>> $ make install
>>
>> Am I missing some library/switch to enable BLF-CRYPT?
>
> Does your libc support it?
>
> $ man crypt || $ man bcrypt
>
>>
>> I just did a quick Google search, and it appears that Ubuntu 14.04 doesn???t have support for BLF-CRYPT according to this issue:
>>
>> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1349252 <https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1349252> <https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1349252 <https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1349252>>
>>
>> Actually, now that I???ve researched this a bit more, it was a mistake for my PHP app to make BLF-CRYPT password hashes since SHA512-CRYPT with a high number of rounds should be just as good. If Ubuntu 16.04 didn't add support for BLF-CRYPT, I guess I will have to implement a Checkpassword script for Dovecot that might generate SHA512-CRYPT replacement hashes after successfully checking against the BLF-CRYPT hashes. I???m no Dovecot expert, but I think I can have multiple passdbs so the first passdb mysql lookup will be set to fail if it finds a BLF-CRYPT hash so the Checkpassword script would only be run once per failed mysql lookup.
>>
>
> Changing your php app will probably be the easiest solution.
>
>> Hopefully, I just missed some ./configure switch to enable BLF-CRYPT and don???t have to deal with converting BLF-CRYPT to SHA512-CRYPT just for Dovecot.
>>
>> Kevin
>>
>>
>>> On Jun 5, 2016, at 7:43 PM, Edgar Pettijohn <edgar at pettijohn-web.com> wrote:
>>>
>>>
>>>
>>> Sent from my iPhone
>>>
>>> On Jun 5, 2016, at 6:16 PM, KT Walrus <kevin at my.walr.us> wrote:
>>>
>>>>> I would love to know why your ubuntu 14.04 system doesn't support sha512-crypt.
>>>>
>>>> I just tried SHA512-CRYPT and it is supported on Ubuntu 14.04. I think I was thinking about DBMail instead of Dovecot.
>>>>
>>>> I could really use support for BLF-CRYPT since my current password hashes generated by PHP are using Blowfish encryption.
>>>>
>>>> Maybe, Dovecot could just add support for BLF-CRYPT by using the open source implementation of Blowfish hashing found in https://github.com/php/php-src/tree/master/ext/standard <https://github.com/php/php-src/tree/master/ext/standard>. The implementation looks like a single function to generate the hash. I???m not much of a programmer, but it would seem to me that these .c/.h files could be added to Dovecot for doing BLF-CRYPT hashing.
>>>>
>>> It already does. As previously stated.
>>>
>>>
>>>> This would mean all installations of Dovecot going forward would support BLF-CRYPT regardless of whether the crypt libraries have Blowfish built in.
>>>>
>>>> Kevin
>>>>
>>>>> On Jun 4, 2016, at 9:53 AM, Patrick Domack <patrickdk at patrickdk.com> wrote:
>>>>>
>>>>>
>>>>> Quoting KT Walrus <kevin at my.walr.us <mailto:kevin at my.walr.us>>:
>>>>>
>>>>>> (I subscribed to a daily digest for this list and can???t figure out how to reply to a reply.)
>>>>>>
>>>>>> Anyway, Aki Tuomi replied to my feature request saying:
>>>>>>
>>>>>>> We support in latest 2.2 release
>>>>>>>
>>>>>>> MD5 MD5-CRYPT SHA SHA1 SHA256 SHA512 SMD5 SSHA SSHA256 SSHA512 PLAIN
>>>>>>> CLEAR CLEARTEXT PLAIN-TRUNC CRAM-MD5 SCRAM-SHA-1 HMAC-MD5 DIGEST-MD5
>>>>>>> PLAIN-MD4 PLAIN-MD5 LDAP-MD5 LANMAN NTLM OTP SKEY RPA CRYPT SHA256-CRYPT
>>>>>>> SHA512-CRYPT
>>>>>>>
>>>>>>> There is also blowfish support as BLF-CRYPT, but that requires that your
>>>>>>> system supports it. CRYPT supports whatever your crypt() supports.
>>>>>>
>>>>>> The reason I suggest building in fallback hash type support is that my install of Dovecot on Ubuntu 14.04 didn???t support SHA512-CRYPT or BLF-CRYPT.
>>>>>>
>>>>>> If Dovecot just included the PHP .c files to make sure it can process Blowfish/SHA512 password hashes on all installs, it would greatly simplify adding Dovecot as a service for my existing user accounts (without forcing them to give their password for the site so I can generate new hashes in a form that Dovecot supports). SHA256-CRYPT is probably my best option for password hashing since it supports ROUNDS to make hash generation slower. But, I would rather use BLF-CRYPT so I can re-use my existing hashes for my user accounts.
>>>>>
>>>>> I would love to know why your ubuntu 14.04 system doesn't support sha512-crypt.
>>>>>
>>>>> My dovecot installs have only ever used sha512-crypt since 2008. Been using ubuntu since 7.04 with sha512-crypt, and my current systems running 14.04 and 16.04 both use sha512-crypt.
>>>>>
>>>>> The default password hash for system user accounts in ubuntu has been sha512-crypt for a very long time now.
>
> --
> Edgar Pettijohn
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