Beef up a bunch of the dovecot config and other tweaks for auth
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/roles/mail/files/dovecot.10-mail.conf Tue Nov 30 01:41:15 2021 -0600
@@ -0,0 +1,421 @@
+## Mailbox locations and namespaces +# Location for users' mailboxes. The default is empty, which means that Dovecot +# tries to find the mailboxes automatically. This won't work if the user +# doesn't yet have any mail, so you should explicitly tell Dovecot the full +# If you're using mbox, giving a path to the INBOX file (eg. /var/mail/%u) +# isn't enough. You'll also need to tell Dovecot where the other mailboxes are +# kept. This is called the "root mail directory", and it must be the first +# path given in the mail_location setting. +# There are a few special variables you can use, eg.: +# %n - user part in user@domain, same as %u if there's no domain +# %d - domain part in user@domain, empty if there's no domain +# See doc/wiki/Variables.txt for full list. Some examples: +# mail_location = maildir:~/Maildir +# mail_location = mbox:~/mail:INBOX=/var/mail/%u +# mail_location = mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%n +# <doc/wiki/MailLocation.txt> +mail_location = maildir:%h/INBOX +# If you need to set multiple mailbox locations or want to change default +# namespace settings, you can do it by defining namespace sections. +# You can have private, shared and public namespaces. Private namespaces +# are for user's personal mails. Shared namespaces are for accessing other +# users' mailboxes that have been shared. Public namespaces are for shared +# mailboxes that are managed by sysadmin. If you create any shared or public +# namespaces you'll typically want to enable ACL plugin also, otherwise all +# users can access all the shared mailboxes, assuming they have permissions +# on filesystem level to do so. + # Namespace type: private, shared or public + # Hierarchy separator to use. You should use the same separator for all + # namespaces or some clients get confused. '/' is usually a good one. + # The default however depends on the underlying mail storage format. + # Prefix required to access this namespace. This needs to be different for + # all namespaces. For example "Public/". + # Physical location of the mailbox. This is in same format as + # mail_location, which is also the default for it. + # There can be only one INBOX, and this setting defines which namespace + # If namespace is hidden, it's not advertised to clients via NAMESPACE + # extension. You'll most likely also want to set list=no. This is mostly + # useful when converting from another server with different namespaces which + # you want to deprecate but still keep working. For example you can create + # hidden namespaces with prefixes "~/mail/", "~%u/mail/" and "mail/". + # Show the mailboxes under this namespace with LIST command. This makes the + # namespace visible for clients that don't support NAMESPACE extension. + # "children" value lists child mailboxes, but hides the namespace prefix. + # Namespace handles its own subscriptions. If set to "no", the parent + # namespace handles them (empty prefix should always have this as "yes") + # See 15-mailboxes.conf for definitions of special mailboxes. +# Example shared namespace configuration + # Mailboxes are visible under "shared/user@domain/" + # %%n, %%d and %%u are expanded to the destination user. + # Mail location for other users' mailboxes. Note that %variables and ~/ + # expands to the logged in user's data. %%n, %%d, %%u and %%h expand to the + # destination user's data. + #location = maildir:%%h/Maildir:INDEX=~/Maildir/shared/%%u + # Use the default namespace for saving subscriptions. + # List the shared/ namespace only if there are visible shared mailboxes. +# Should shared INBOX be visible as "shared/user" or "shared/user/INBOX"? +#mail_shared_explicit_inbox = no +# System user and group used to access mails. If you use multiple, userdb +# can override these by returning uid or gid fields. You can use either numbers +# or names. <doc/wiki/UserIds.txt> +# Group to enable temporarily for privileged operations. Currently this is +# used only with INBOX when either its initial creation or dotlocking fails. +# Typically this is set to "mail" to give access to /var/mail. +mail_privileged_group = mail +# Grant access to these supplementary groups for mail processes. Typically +# these are used to set up access to shared mailboxes. Note that it may be +# dangerous to set these if users can create symlinks (e.g. if "mail" group is +# set here, ln -s /var/mail ~/mail/var could allow a user to delete others' +# mailboxes, or ln -s /secret/shared/box ~/mail/mybox would allow reading it). +# Allow full filesystem access to clients. There's no access checks other than +# what the operating system does for the active UID/GID. It works with both +# maildir and mboxes, allowing you to prefix mailboxes names with eg. /path/ +#mail_full_filesystem_access = no +# Dictionary for key=value mailbox attributes. This is used for example by +# URLAUTH and METADATA extensions. +# A comment or note that is associated with the server. This value is +# accessible for authenticated users through the IMAP METADATA server +# entry "/shared/comment". +#mail_server_comment = "" +# Indicates a method for contacting the server administrator. According to +# RFC 5464, this value MUST be a URI (e.g., a mailto: or tel: URL), but that +# is currently not enforced. Use for example mailto:admin@example.com. This +# value is accessible for authenticated users through the IMAP METADATA server +# entry "/shared/admin". +# Don't use mmap() at all. This is required if you store indexes to shared +# filesystems (NFS or clustered filesystem). +# Rely on O_EXCL to work when creating dotlock files. NFS supports O_EXCL +# since version 3, so this should be safe to use nowadays by default. +# When to use fsync() or fdatasync() calls: +# optimized (default): Whenever necessary to avoid losing important data +# always: Useful with e.g. NFS when write()s are delayed +# never: Never use it (best performance, but crashes can lose data) +# Locking method for index files. Alternatives are fcntl, flock and dotlock. +# Dotlocking uses some tricks which may create more disk I/O than other locking +# methods. NFS users: flock doesn't work, remember to change mmap_disable. +# Directory where mails can be temporarily stored. Usually it's used only for +# mails larger than >= 128 kB. It's used by various parts of Dovecot, for +# example LDA/LMTP while delivering large mails or zlib plugin for keeping +# Valid UID range for users, defaults to 500 and above. This is mostly +# to make sure that users can't log in as daemons or other system users. +# Note that denying root logins is hardcoded to dovecot binary and can't +# be done even if first_valid_uid is set to 0. +# Valid GID range for users, defaults to non-root/wheel. Users having +# non-valid GID as primary group ID aren't allowed to log in. If user +# belongs to supplementary groups with non-valid GIDs, those groups are +# Maximum allowed length for mail keyword name. It's only forced when trying +# to create new keywords. +#mail_max_keyword_length = 50 +# ':' separated list of directories under which chrooting is allowed for mail +# processes (ie. /var/mail will allow chrooting to /var/mail/foo/bar too). +# This setting doesn't affect login_chroot, mail_chroot or auth chroot +# settings. If this setting is empty, "/./" in home dirs are ignored. +# WARNING: Never add directories here which local users can modify, that +# may lead to root exploit. Usually this should be done only if you don't +# allow shell access for users. <doc/wiki/Chrooting.txt> +# Default chroot directory for mail processes. This can be overridden for +# specific users in user database by giving /./ in user's home directory +# (eg. /home/./user chroots into /home). Note that usually there is no real +# need to do chrooting, Dovecot doesn't allow users to access files outside +# their mail directory anyway. If your home directories are prefixed with +# the chroot directory, append "/." to mail_chroot. <doc/wiki/Chrooting.txt> +# UNIX socket path to master authentication server to find users. +# This is used by imap (for shared users) and lda. +#auth_socket_path = /var/run/dovecot/auth-userdb +# Directory where to look up mail plugins. +#mail_plugin_dir = /usr/lib/dovecot/modules +# Space separated list of plugins to load for all services. Plugins specific to +# IMAP, LDA, etc. are added to this list in their own .conf files. +## Mailbox handling optimizations +# Mailbox list indexes can be used to optimize IMAP STATUS commands. They are +# also required for IMAP NOTIFY extension to be enabled. +#mailbox_list_index = yes +# Trust mailbox list index to be up-to-date. This reduces disk I/O at the cost +# of potentially returning out-of-date results after e.g. server crashes. +# The results will be automatically fixed once the folders are opened. +#mailbox_list_index_very_dirty_syncs = yes +# Should INBOX be kept up-to-date in the mailbox list index? By default it's +# not, because most of the mailbox accesses will open INBOX anyway. +#mailbox_list_index_include_inbox = no +# The minimum number of mails in a mailbox before updates are done to cache +# file. This allows optimizing Dovecot's behavior to do less disk writes at +# the cost of more disk reads. +#mail_cache_min_mail_count = 0 +# When IDLE command is running, mailbox is checked once in a while to see if +# there are any new mails or other changes. This setting defines the minimum +# time to wait between those checks. Dovecot can also use inotify and +# kqueue to find out immediately when changes occur. +#mailbox_idle_check_interval = 30 secs +# Save mails with CR+LF instead of plain LF. This makes sending those mails +# take less CPU, especially with sendfile() syscall with Linux and FreeBSD. +# But it also creates a bit more disk I/O which may just make it slower. +# Also note that if other software reads the mboxes/maildirs, they may handle +# the extra CRs wrong and cause problems. +# Max number of mails to keep open and prefetch to memory. This only works with +# some mailbox formats and/or operating systems. +#mail_prefetch_count = 0 +# How often to scan for stale temporary files and delete them (0 = never). +# These should exist only after Dovecot dies in the middle of saving mails. +#mail_temp_scan_interval = 1w +# How many slow mail accesses sorting can perform before it returns failure. +# With IMAP the reply is: NO [LIMIT] Requested sort would have taken too long. +# The untagged SORT reply is still returned, but it's likely not correct. +#mail_sort_max_read_count = 0 +protocol !indexer-worker { + # If folder vsize calculation requires opening more than this many mails from + # disk (i.e. mail sizes aren't in cache already), return failure and finish + # the calculation via indexer process. Disabled by default. This setting must + # be 0 for indexer-worker processes. + #mail_vsize_bg_after_count = 0 +## Maildir-specific settings +# By default LIST command returns all entries in maildir beginning with a dot. +# Enabling this option makes Dovecot return only entries which are directories. +# This is done by stat()ing each entry, so it causes more disk I/O. +# (For systems setting struct dirent->d_type, this check is free and it's +# done always regardless of this setting) +# When copying a message, do it with hard links whenever possible. This makes +# the performance much better, and it's unlikely to have any side effects. +#maildir_copy_with_hardlinks = yes +# Assume Dovecot is the only MUA accessing Maildir: Scan cur/ directory only +# when its mtime changes unexpectedly or when we can't find the mail otherwise. +#maildir_very_dirty_syncs = no +# If enabled, Dovecot doesn't use the S=<size> in the Maildir filenames for +# getting the mail's physical size, except when recalculating Maildir++ quota. +# This can be useful in systems where a lot of the Maildir filenames have a +# broken size. The performance hit for enabling this is very small. +#maildir_broken_filename_sizes = no +# Always move mails from new/ directory to cur/, even when the \Recent flags +## mbox-specific settings +# Which locking methods to use for locking mbox. There are four available: +# dotlock: Create <mailbox>.lock file. This is the oldest and most NFS-safe +# solution. If you want to use /var/mail/ like directory, the users +# will need write access to that directory. +# dotlock_try: Same as dotlock, but if it fails because of permissions or +# because there isn't enough disk space, just skip it. +# fcntl : Use this if possible. Works with NFS too if lockd is used. +# flock : May not exist in all systems. Doesn't work with NFS. +# lockf : May not exist in all systems. Doesn't work with NFS. +# You can use multiple locking methods; if you do the order they're declared +# in is important to avoid deadlocks if other MTAs/MUAs are using multiple +# locking methods as well. Some operating systems don't allow using some of +# The Debian value for mbox_write_locks differs from upstream Dovecot. It is +# changed to be compliant with Debian Policy (section 11.6) for NFS safety. +# Dovecot: mbox_write_locks = dotlock fcntl +# Debian: mbox_write_locks = fcntl dotlock +#mbox_read_locks = fcntl +#mbox_write_locks = fcntl dotlock +# Maximum time to wait for lock (all of them) before aborting. +#mbox_lock_timeout = 5 mins +# If dotlock exists but the mailbox isn't modified in any way, override the +# lock file after this much time. +#mbox_dotlock_change_timeout = 2 mins +# When mbox changes unexpectedly we have to fully read it to find out what +# changed. If the mbox is large this can take a long time. Since the change +# is usually just a newly appended mail, it'd be faster to simply read the +# new mails. If this setting is enabled, Dovecot does this but still safely +# fallbacks to re-reading the whole mbox file whenever something in mbox isn't +# how it's expected to be. The only real downside to this setting is that if +# some other MUA changes message flags, Dovecot doesn't notice it immediately. +# Note that a full sync is done with SELECT, EXAMINE, EXPUNGE and CHECK +# Like mbox_dirty_syncs, but don't do full syncs even with SELECT, EXAMINE, +# EXPUNGE or CHECK commands. If this is set, mbox_dirty_syncs is ignored. +#mbox_very_dirty_syncs = no +# Delay writing mbox headers until doing a full write sync (EXPUNGE and CHECK +# commands and when closing the mailbox). This is especially useful for POP3 +# where clients often delete all mails. The downside is that our changes +# aren't immediately visible to other MUAs. +# If mbox size is smaller than this (e.g. 100k), don't write index files. +# If an index file already exists it's still read, just not updated. +#mbox_min_index_size = 0 +# Mail header selection algorithm to use for MD5 POP3 UIDLs when +# pop3_uidl_format=%m. For backwards compatibility we use apop3d inspired +# algorithm, but it fails if the first Received: header isn't unique in all +# mails. An alternative algorithm is "all" that selects all headers. +## mdbox-specific settings +# Maximum dbox file size until it's rotated. +#mdbox_rotate_size = 10M +# Maximum dbox file age until it's rotated. Typically in days. Day begins +# from midnight, so 1d = today, 2d = yesterday, etc. 0 = check disabled. +#mdbox_rotate_interval = 0 +# When creating new mdbox files, immediately preallocate their size to +# mdbox_rotate_size. This setting currently works only in Linux with some +# filesystems (ext4, xfs). +#mdbox_preallocate_space = no +# sdbox and mdbox support saving mail attachments to external files, which +# also allows single instance storage for them. Other backends don't support +# Directory root where to store mail attachments. Disabled, if empty. +# Attachments smaller than this aren't saved externally. It's also possible to +# write a plugin to disable saving specific attachments externally. +#mail_attachment_min_size = 128k +# Filesystem backend to use for saving attachments: +# posix : No SiS done by Dovecot (but this might help FS's own deduplication) +# sis posix : SiS with immediate byte-by-byte comparison during saving +# sis-queue posix : SiS with delayed comparison and deduplication +#mail_attachment_fs = sis posix +# Hash format to use in attachment filenames. You can add any text and +# variables: %{md4}, %{md5}, %{sha1}, %{sha256}, %{sha512}, %{size}. +# Variables can be truncated, e.g. %{sha256:80} returns only first 80 bits +#mail_attachment_hash = %{sha1} +# Settings to control adding $HasAttachment or $HasNoAttachment keywords. +# By default, all MIME parts with Content-Disposition=attachment, or inlines +# with filename parameter are consired attachments. +# add-flags - Add the keywords when saving new mails or when fetching can +# content-type=type or !type - Include/exclude content type. Excluding will +# never consider the matched MIME part as attachment. Including will only +# negate an exclusion (e.g. content-type=!foo/* content-type=foo/bar). +# exclude-inlined - Exclude any Content-Disposition=inline MIME part. +#mail_attachment_detection_options = --- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/roles/mail/files/dovecot.10-master.conf Tue Nov 30 01:41:15 2021 -0600
@@ -0,0 +1,136 @@
+#default_process_limit = 100 +#default_client_limit = 1000 +# Default VSZ (virtual memory size) limit for service processes. This is mainly +# intended to catch and kill processes that leak memory before they eat up +#default_vsz_limit = 256M +# Login user is internally used by login processes. This is the most untrusted +# user in Dovecot system. It shouldn't have access to anything at all. +#default_login_user = dovenull +# Internal user is used by unprivileged processes. It should be separate from +# login user, so that login processes can't disturb other processes. +#default_internal_user = dovecot + # Number of connections to handle before starting a new process. Typically + # the only useful values are 0 (unlimited) or 1. 1 is more secure, but 0 + # is faster. <doc/wiki/LoginProcess.txt> + # Number of processes to always keep waiting for more connections. + # If you set service_count=0, you probably need to grow this. + #vsz_limit = $default_vsz_limit +service submission-login { + inet_listener submission { + # Create inet listener only if you can't use the above UNIX socket + # Avoid making LMTP visible for the entire internet + unix_listener /var/spool/postfix/private/dovecot-lmtp { + # Most of the memory goes to mmap()ing files. You may need to increase this + # limit if you have huge mailboxes. + #vsz_limit = $default_vsz_limit + # Max. number of IMAP processes (connections) + # Max. number of POP3 processes (connections) + # Max. number of SMTP Submission processes (connections) + # auth_socket_path points to this userdb socket by default. It's typically + # used by dovecot-lda, doveadm, possibly imap process, etc. Users that have + # full permissions to this socket are able to get a list of all usernames and + # get the results of everyone's userdb lookups. + # The default 0666 mode allows anyone to connect to the socket, but the + # userdb lookups will succeed only if the userdb returns an "uid" field that + # matches the caller process's UID. Also if caller's uid or gid matches the + # socket's uid or gid the lookup succeeds. Anything else causes a failure. + # To give the caller full permissions to lookup all users, set the mode to + # something else than 0666 and Dovecot lets the kernel enforce the + # permissions (e.g. 0777 allows everyone full permissions). + unix_listener auth-userdb { + unix_listener /var/spool/postfix/private/auth { + # Auth process is run as this user. + #user = $default_internal_user + # Auth worker process is run as root by default, so that it can access + # /etc/shadow. If this isn't necessary, the user should be changed to + # $default_internal_user. + # If dict proxy is used, mail processes should have access to its socket. + # For example: mode=0660, group=vmail and global mail_access_groups=vmail --- a/roles/mail/tasks/dovecot.yaml Mon Nov 29 21:18:05 2021 -0600
+++ b/roles/mail/tasks/dovecot.yaml Tue Nov 30 01:41:15 2021 -0600
@@ -1,4 +1,12 @@
+- name: "allow imap traffic" - name: "install dovecot"
@@ -31,20 +39,18 @@
dest: /etc/fail2ban/jail.d/dovecot.conf
notify: "restart fail2ban"
-- name: "check for packaged 10-auth.conf"- path: "/etc/dovecot/conf.d/10-auth.conf"- register: "packaged_10_auth_conf"-- name: "move 10-auth.conf out of the way"- command: "mv /etc/dovecot/conf.d/10-auth.conf /etc/dovecot/conf.d/10-auth.conf.orig"- when: "packaged_10_auth_conf.stat.exists"-- name: "copy 10-auth.conf"+- name: "copy configuration" - src: "dovecot.10-auth.conf"- dest: "/etc/dovecot/conf.d/10-auth.conf"+ dest: "/etc/dovecot/conf.d/{{ item.dest }}" + - src: "dovecot.10-auth.conf" + - src: "dovecot.10-mail.conf" + - src: "dovecot.10-master.conf" - name: "add checkpassword based auth configuration"
--- a/roles/mail/templates/dovecot-10-auth-checkpassword.conf.j2 Mon Nov 29 21:18:05 2021 -0600
+++ b/roles/mail/templates/dovecot-10-auth-checkpassword.conf.j2 Tue Nov 30 01:41:15 2021 -0600
@@ -3,7 +3,12 @@
args = /usr/local/bin/dovecot-auth-imf-hub.py
- args = uid={{ mail_user }} gid={{ mail_group }} home={{ mail_home }}/%d/%n+ args = /usr/local/bin/dovecot-auth-imf-hub.py --- a/roles/mail/templates/dovecot-auth-imf-hub.py.j2 Mon Nov 29 21:18:05 2021 -0600
+++ b/roles/mail/templates/dovecot-auth-imf-hub.py.j2 Tue Nov 30 01:41:15 2021 -0600
@@ -9,6 +9,7 @@
@@ -105,9 +106,6 @@
@@ -117,7 +115,7 @@
- username = username.decode("utf-8")+ username = username.decode("utf-8").lower() password = password.decode("utf-8")
@@ -134,6 +132,7 @@
if not check_group(user, domain):
+ os.environ["AUTHORIZED"] = "2" if not validate_credentials(user, domain, password):
@@ -142,11 +141,14 @@
+ home = os.path.join("{{ mail_home }}", domain, user) - "EXTRA": "userdb_uid userdb_gid"+ "USER": f"{user}@{domain}", + "EXTRA": "userdb_uid userdb_gid userdb_mail", os.execvp(sys.argv[1], sys.argv[1:])
