Blowfish hashed passwords

[Edgar Pettijohn]

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>
> 
> 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