I'm using dovecot version 2.3.2.1 (0719df592) and trying to use the
ARGON2ID crypt scheme for authentication using the passdb passwd-file
driver. My passdb config is very simple:
passdb {
driver = passwd-file
args = username_format=%u <path-to-file-here>
}
If I generate a password this way:
doveadm pw -s ARGON2ID -p 'This is a test'
I get a crypt value for the password that I can place in the password
file like:
testuser:{ARGON2ID}$argon2id$v=19$m=65536,t=3,p=1$UuqF25QtumNBe9R2FmUZvA$5avvHY5TIaj5Wl5C4k8BOI4bcmNei7BwPLlXYQVybMc
And if I test authentication with this command:
doveadm auth login testuser 'This is a test'
It works as shown by the (lightly redacted) log:
Sep 25 22:46:01 myhost dovecot[17538]: auth: Debug: auth client
connected (pid=55417)
Sep 25 22:46:01 myhost dovecot[17538]: auth: Debug: client in:
AUTH 1 PLAIN service=doveadm debug resp=<hidden>
Sep 25 22:46:01 myhost dovecot[17538]: auth: Debug:
passwd-file(testuser): lookup: user=testuser file=<path-to-passwd-file>
Sep 25 22:46:01 myhost dovecot[17538]: auth: Debug: client passdb
out: OK 1 user=testuser
However, if I instead specify a non-default number of rounds this way:
doveadm pw -s ARGON2ID -p 'This is a test' -r 7
and place the result in an entry in the password file like:
testuser:{ARGON2ID}$argon2id$v=19$m=1048576,t=7,p=1$kIhnUR13GrtOvvpbJNJmnQ$o7O6Whxs3s8IE09yY9S2dPkJjJyEVc78GRFilYVS9fU
Then testing authentication using the same command (repeated here):
doveadm auth login testuser 'This is a test'
then authentication fails, as shown by this (lightly redacted) log:
Sep 25 22:52:05 myhost dovecot[17538]: auth: Debug: auth client
connected (pid=55557)
Sep 25 22:52:05 myhost dovecot[17538]: auth: Debug: client in:
AUTH 1 PLAIN service=doveadm debug resp=<hidden>
Sep 25 22:52:05 myhost dovecot[17538]: auth: Debug: passwd-file
<path-to-passwd-file>: Read 3 users in 0 secs
Sep 25 22:52:05 myhost dovecot[17538]: auth: Debug:
passwd-file(testuser): lookup: user=testuser file=<path-to-passwd-file>
Sep 25 22:52:05 myhost dovecot[17538]: auth: passwd-file(testuser):
Password mismatch
Sep 25 22:52:07 myhost dovecot[17538]: auth: Debug: client passdb
out: FAIL 1 user=testuser
Experimentation with other values for the -r option has not produced
a value that works for me. Using the exact same procedure but the
BLF-CRYPT scheme, with varying number of rounds, does work.
Am I doing something wrong or is there a bug in either the
doveadm pw generation or the auth evaluation of the password?
I'd like to use ARGON2ID with ~6 rounds if I can make this work.
Any help would be greatly appreciated.
Thanks, Keith
