Mail user password management

Slagroom · September 22, 2023, 9:11am

As I understood from View user passwords for email accounts hestia stores user email passwords encrypted. If people login, their passwords are being matched with what is stored. So you decrypt them at that stage. So you can make a list of all of them as well, with the right script.
I’d like to perform just the decryption to make migrating email user accounts easier for them.

eris · September 22, 2023, 9:19am

You can’t decrypt the password.

We store it as Bcrypt by default (Fail back to ArgonID or MD5) when the first methods are not availble

github.com

hestiacp/hestiacp/blob/1d827b155389e6d8c470c7650f9cd42117f3b77e/bin/v-change-mail-account-password#L60-L71


      
          if [ -n "$(doveadm pw -l | grep BLF-CRYPT)" ]; then
          	set +H # disable ! style history substitution
          	md5="$(doveadm pw -s BLF-CRYPT -p "$password")"
          elif [ -n "$(doveadm pw -l | grep ARGON2ID)" ]; then
          	# Fall back on Argon2id if bcrypt is not available
          	set +H # disable ! style history substitution
          	md5="$(doveadm pw -s ARGON2ID -p "$password")"
          else
          	# Fall back on MD5 if neither bcrypt nor argon2id is available
          	salt=$(generate_password "$PW_MATRIX" "8")
          	md5="{MD5}$($BIN/v-generate-password-hash md5 $salt <<< $password)"
          fi

(But that would mean Debian 9 or lower…)

Dovecot does the same and also need to ecrypt the password with the same salt and compare the passwords…

Slagroom · September 22, 2023, 9:48am

So the only way to retrieve a current password unencrypted is by grabbing it from RAM in between or some such scenario?

eris · September 22, 2023, 9:51am

BCRYPT and ArgonID and MD5 are never reversible (For md5 you can of course use rainbow tables…) So the only moment when you can grab the unencrypted password is when a password has been changed and or account has been created …