Re: Blowfish hashed passwords

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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?

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?

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.

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@pettijohn-web.com wrote:

Sent from my iPhone

On Jun 5, 2016, at 6:16 PM, KT Walrus kevin@my.walr.us wrote:

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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.

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This would mean all installations of Dovecot going forward would support BLF-CRYPT regardless of whether the crypt libraries have Blowfish built in.

Kevin

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On Jun 4, 2016, at 9:53 AM, Patrick Domack patrickdk@patrickdk.com wrote:

Quoting KT Walrus mailto:kevin@my.walr.us>:

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(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:

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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.