Blowfish hashed passwords

Edgar Pettijohn edgar at pettijohn-web.com
Sun Jun 5 23:43:04 UTC 2016



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.



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