Using SHA256/512 for SQL based password

[Robert Moskowitz]

On 2/13/19 1:23 AM, Matthias Fechner via dovecot wrote:
>
>
> Am 13. Februar 2019 00:34:15 schrieb Robert Moskowitz 
> <rgm at htt-consult.com>:
>
>> On 2/12/19 6:03 PM, Matthias Fechner via dovecot wrote:
>>> Am 12.02.2019 um 17:05 schrieb Robert Moskowitz via dovecot:
>>>> I have trying to find how to set the dovecot-sql.conf for using
>>>> SHA256/512.  I am going to start clean with the stronger format, not
>>>> migrate from the old MD5.  It seems all I need is:
>>> you maybe would like to have a look to the hashing algo ARGON2I 
>>> which is
>>> currently recommended for new developments and deployments.
>>
>> Recommended by whom?
>>
>> Can you provide a link?
>
> Sure, please see here:
> https://www.owasp.org/index.php/Password_Storage_Cheat_Sheet
>
>>
>>
>> And if I was adventurous about hashes, I would be looking more at 
>> Keccak.
>>
>>
>> Check out my Internet Draft:
>>
>>
>> draft-moskowitz-small-crypto-00.txt
>
> Thanks for the tip, will have a look for into it.

Keccak is a general hashing function.  It was the first? of the hashing 
'sponge' functions, that many have followed.  It is the basis of SHA3 
(at Keccak's greatest strength).

Argon2 seems to be special-built for password hashing.  Thing is it is 
not supported on my CentOS7 system:

# doveadm pw -l
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 PBKDF2 CRYPT 
SHA256-CRYPT SHA512-CRYPT

Of course SHA3 is not listed either...