Argon2 for Dovecot on Debian

TL;DR

echo "deb https://packages.sury.org/php/ stretch main" > /etc/apt/sources.list.d/sury.list
apt-get update
apt-get install libsodium-dev dovecot-dev build-essential libtool-bin
git clone https://github.com/LuckyFellow/dovecot-libsodium-plugin
cd dovecot-libsodium-plugin
./autogen.sh
./configure --with-dovecot=/usr/lib/dovecot --with-moduledir=/usr/lib/dovecot/modules
make
make install
libtool --finish /usr/local/lib/dovecot/auth

Details

the dovecot wiki tells us, that Argon2 is currently the most secure hashing algorithm. dovecot on debian stretch doesn't has the argon2 algorithm bundled.

root@mail:~# 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

to be able to use doveadm pw -s argon2 you need to install the dovecot-libsodium-plugin. means build it yourself (but only the extension).

• configure packages.sury.org/php als apt repository
• install required packages
• clone the dovecot-libsodium-plugin repo
• build (you have to specify the dovecot and module path on debian)

not sure about the sury repo, only noticed, that after i have installed the php-sodium extension, the libsodium23 and libsodium-dev where installed from there

Get:1 https://packages.sury.org/php stretch/main amd64 libsodium23 amd64 1.0.16-2+0~20180103211631.7+stretch~1.gbpb56693 [153 kB]
Get:2 https://packages.sury.org/php stretch/main amd64 libsodium-dev amd64 1.0.16-2+0~20180103211631.7+stretch~1.gbpb56693 [171 kB]

after the installation you should get this:

root@mail:~/dovecot-libsodium-plugin# 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 SCRYPT ARGON2

• edited and enhanced after reading https://github.com/LuckyFellow/dovecot-libsodium-plugin/issues/6#issuecomment-350849536
• cover image by Pixabay https://www.pexels.com/photo/door-handle-key-keyhole-279810/