function auth_password_verify(req, pass)
 local handle = io.popen("/usr/local/vpopmail/bin/vuserinfo -p "..req.user)
 local result = handle:read("*a")
 handle:close()

 local epass = result:match "^%s*(.-)%s*$"
 if req:password_verify("{MD5-CRYPT}"..epass,pass) > 0 then
   return dovecot.auth.PASSDB_RESULT_OK, {}
 end
 return dovecot.auth.PASSDB_RESULT_PASSWORD_MISMATCH, {}
end

function auth_userdb_lookup(req)
 local handle = io.popen("/usr/local/vpopmail/bin/vuserinfo -d "..req.user)
 local result = handle:read("*a")
 handle:close()

 if result:find("no such user") ~= nil then
  return dovecot.auth.USERDB_RESULT_USER_UNKNOWN, "no such user"
 end
 return dovecot.auth.USERDB_RESULT_OK, "uid=vpopmail gid=vchkpw home="..result:match "^%s*(.-)%s*$"
end