IMAP: Update role to Debian Buster.

For `ssl_cipher_list` we pick the suggested value from
https://ssl-config.mozilla.org/#server=dovecot&version=2.3.9&config=intermediate&openssl=1.1.1d

At the moment it's equivalent (modulo order) to adding ‘EDH+AESGCM+aRSA’
to ‘EECDH+AESGCM:EECDH+CHACHA20!MEDIUM!LOW!EXP!aNULL!eNULL’.

8 files changed, 100 insertions, 112 deletions

diff --git a/roles/IMAP/files/etc/dovecot/conf.d/10-logging.conf b/roles/IMAP/files/etc/dovecot/conf.d/10-logging.conf
deleted file mode 100644
index 848fe69..0000000
--- a/roles/IMAP/files/etc/dovecot/conf.d/10-logging.conf
+++ /dev/null
@@ -1,85 +0,0 @@
-##
-## Log destination.
-##
-
-# Log file to use for error messages. "syslog" logs to syslog,
-# /dev/stderr logs to stderr.
-#log_path = syslog
-
-# Log file to use for informational messages. Defaults to log_path.
-#info_log_path =
-# Log file to use for debug messages. Defaults to info_log_path.
-#debug_log_path =
-
-# Syslog facility to use if you're logging to syslog. Usually if you don't
-# want to use "mail", you'll use local0..local7. Also other standard
-# facilities are supported.
-#syslog_facility = mail
-
-##
-## Logging verbosity and debugging.
-##
-
-# Log unsuccessful authentication attempts and the reasons why they failed.
-#auth_verbose = no
-
-# In case of password mismatches, log the attempted password. Valid values are
-# no, plain and sha1. sha1 can be useful for detecting brute force password
-# attempts vs. user simply trying the same password over and over again.
-# You can also truncate the value to n chars by appending ":n" (e.g. sha1:6).
-#auth_verbose_passwords = no
-
-# Even more verbose logging for debugging purposes. Shows for example SQL
-# queries.
-#auth_debug = no
-
-# In case of password mismatches, log the passwords and used scheme so the
-# problem can be debugged. Enabling this also enables auth_debug.
-#auth_debug_passwords = no
-
-# Enable mail process debugging. This can help you figure out why Dovecot
-# isn't finding your mails.
-#mail_debug = no
-
-# Show protocol level SSL errors.
-#verbose_ssl = no
-
-# mail_log plugin provides more event logging for mail processes.
-plugin {
-  # Events to log. Also available: flag_change append
-  #mail_log_events = delete undelete expunge copy mailbox_delete mailbox_rename
-  # Available fields: uid, box, msgid, from, subject, size, vsize, flags
-  # size and vsize are available only for expunge and copy events.
-  #mail_log_fields = uid box msgid size
-}
-
-##
-## Log formatting.
-##
-
-# Prefix for each line written to log file. % codes are in strftime(3)
-# format.
-log_timestamp = "%Y-%m-%d %H:%M:%S "
-
-# Space-separated list of elements we want to log. The elements which have
-# a non-empty variable value are joined together to form a comma-separated
-# string.
-#login_log_format_elements = user=<%u> method=%m rip=%r lip=%l mpid=%e %c
-
-# Login log format. %s contains login_log_format_elements string, %$ contains
-# the data we want to log.
-#login_log_format = %$: %s
-
-# Log prefix for mail processes. See doc/wiki/Variables.txt for list of
-# possible variables you can use.
-#mail_log_prefix = "%s(%u): "
-
-# Format to use for logging mail deliveries. See doc/wiki/Variables.txt for
-# list of all variables you can use. Some of the common ones include:
-#  %$ - Delivery status message (e.g. "saved to INBOX")
-#  %m - Message-ID
-#  %s - Subject
-#  %f - From address
-#  %p - Physical size
-#  %w - Virtual size
-#deliver_log_format = msgid=%m: %$
diff --git a/roles/IMAP/files/etc/dovecot/conf.d/10-mail.conf b/roles/IMAP/files/etc/dovecot/conf.d/10-mail.conf
index a781402..d74b026 100644
--- a/roles/IMAP/files/etc/dovecot/conf.d/10-mail.conf
+++ b/roles/IMAP/files/etc/dovecot/conf.d/10-mail.conf
@@ -118,7 +118,7 @@ mail_gid = vmail
 # 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_privileged_group =
 
 # 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
@@ -172,7 +172,10 @@ mail_server_admin = mailto:postmaster@fripost.org
 # methods. NFS users: flock doesn't work, remember to change mmap_disable.
 #lock_method = fcntl
 
-# Directory in which LDA/LMTP temporarily stores incoming mails >128 kB.
+# 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
+# uncompressed mails.
 #mail_temp_dir = /tmp
 
 # Valid UID range for users, defaults to 500 and above. This is mostly
@@ -219,7 +222,7 @@ first_valid_uid = 1
 
 # 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.
-mail_plugins = quota stats virtual zlib
+mail_plugins = quota virtual zlib
 
 ##
 ## Mailbox handling optimizations
@@ -227,7 +230,16 @@ mail_plugins = quota stats virtual zlib
 
 # 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
+#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
@@ -255,6 +267,19 @@ mailbox_list_index = yes
 # 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
 ##
@@ -354,7 +379,7 @@ mailbox_list_index = yes
 ##
 
 # Maximum dbox file size until it's rotated.
-#mdbox_rotate_size = 2M
+#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.
@@ -390,3 +415,13 @@ mail_attachment_fs = sis-queue /home/mail/attachments/queue:posix
 # variables: %{md4}, %{md5}, %{sha1}, %{sha256}, %{sha512}, %{size}.
 # Variables can be truncated, e.g. %{sha256:80} returns only first 80 bits
 mail_attachment_hash = %{sha256}
+
+# 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-on-save - Add the keywords when saving new mails.
+#   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 =
diff --git a/roles/IMAP/files/etc/dovecot/conf.d/10-ssl.conf b/roles/IMAP/files/etc/dovecot/conf.d/10-ssl.conf
index 209347f..adeb879 100644
--- a/roles/IMAP/files/etc/dovecot/conf.d/10-ssl.conf
+++ b/roles/IMAP/files/etc/dovecot/conf.d/10-ssl.conf
@@ -27,10 +27,11 @@ ssl_key = </etc/dovecot/ssl/imap.fripost.org.key
 #ssl_require_crl = yes
 
 # Directory and/or file for trusted SSL CA certificates. These are used only
-# when Dovecot needs to act as an SSL client (e.g. imapc backend). The
-# directory is usually /etc/ssl/certs in Debian-based systems and the file is
-# /etc/pki/tls/cert.pem in RedHat-based systems.
-#ssl_client_ca_dir =
+# when Dovecot needs to act as an SSL client (e.g. imapc backend or
+# submission service). The directory is usually /etc/ssl/certs in
+# Debian-based systems and the file is /etc/pki/tls/cert.pem in
+# RedHat-based systems.
+ssl_client_ca_dir = /etc/ssl/certs
 #ssl_client_ca_file =
 
 # Request client to send a certificate. If you also want to require it, set
@@ -42,14 +43,23 @@ ssl_key = </etc/dovecot/ssl/imap.fripost.org.key
 # auth_ssl_username_from_cert=yes.
 #ssl_cert_username_field = commonName
 
-# DH parameters length to use.
-ssl_dh_parameters_length = 2048
+# SSL DH parameters
+# Generate new params with `openssl dhparam -out /etc/dovecot/dh.pem 4096`
+# Or migrate from old ssl-parameters.dat file with the command dovecot
+# gives on startup when ssl_dh is unset.
+ssl_dh = </etc/ssl/dhparams.pem
 
-# SSL protocols to use
-#ssl_protocols = !SSLv3
+# Minimum SSL protocol version to use. Potentially recognized values are SSLv3,
+# TLSv1, TLSv1.1, and TLSv1.2, depending on the OpenSSL version used.
+ssl_min_protocol = TLSv1.2
 
 # SSL ciphers to use
-ssl_cipher_list = EECDH+AESGCM:EECDH+CHACHA20!MEDIUM!LOW!EXP!aNULL!eNULL
+ssl_cipher_list = ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384
+
+# Colon separated list of elliptic curves to use. Empty value (the default)
+# means use the defaults from the SSL library. P-521:P-384:P-256 would be an
+# example of a valid value.
+#ssl_curve_list =
 
 # Prefer the server's order of ciphers over client's.
 #ssl_prefer_server_ciphers = no
@@ -58,5 +68,6 @@ ssl_cipher_list = EECDH+AESGCM:EECDH+CHACHA20!MEDIUM!LOW!EXP!aNULL!eNULL
 #ssl_crypto_device =
 
 # SSL extra options. Currently supported options are:
-#   no_compression - Disable compression.
-ssl_options = no_compression
+#   compression - Enable compression.
+#   no_ticket - Disable SSL session tickets.
+#ssl_options =
diff --git a/roles/IMAP/files/etc/dovecot/conf.d/15-lda.conf b/roles/IMAP/files/etc/dovecot/conf.d/15-lda.conf
index 2a7bd27..4bfd8a5 100644
--- a/roles/IMAP/files/etc/dovecot/conf.d/15-lda.conf
+++ b/roles/IMAP/files/etc/dovecot/conf.d/15-lda.conf
@@ -3,7 +3,7 @@
 ##
 
 # Address to use when sending rejection mails.
-# Default is postmaster@<your domain>. %d expands to recipient domain.
+# Default is postmaster@%d. %d expands to recipient domain.
 #postmaster_address =
 
 # Hostname to use in various parts of sent mails (e.g. in Message-Id) and
diff --git a/roles/IMAP/files/etc/dovecot/conf.d/20-imap.conf b/roles/IMAP/files/etc/dovecot/conf.d/20-imap.conf
index 3ddedce..de1fbbb 100644
--- a/roles/IMAP/files/etc/dovecot/conf.d/20-imap.conf
+++ b/roles/IMAP/files/etc/dovecot/conf.d/20-imap.conf
@@ -21,10 +21,17 @@ imap_hibernate_timeout = 15s
 #  %{fetch_body_count} - Number of mails with mail body data sent to client
 #  %{fetch_body_bytes} - Number of bytes with mail body data sent to client
 #  %{deleted} - Number of mails where client added \Deleted flag
-#  %{expunged} - Number of mails that client expunged
+#  %{expunged} - Number of mails that client expunged, which does not
+#                include automatically expunged mails
+#  %{autoexpunged} - Number of mails that were automatically expunged after
+#                    client disconnected
 #  %{trashed} - Number of mails that client copied/moved to the
 #               special_use=\Trash mailbox.
-#imap_logout_format = in=%i out=%o
+#  %{appended} - Number of mails saved during the session
+#imap_logout_format = in=%i out=%o deleted=%{deleted} expunged=%{expunged} \
+#  trashed=%{trashed} hdr_count=%{fetch_hdr_count} \
+#  hdr_bytes=%{fetch_hdr_bytes} body_count=%{fetch_body_count} \
+#  body_bytes=%{fetch_body_bytes}
 
 # Override the IMAP CAPABILITY response. If the value begins with '+',
 # add the given capabilities on top of the defaults (e.g. +XFOO XBAR).
@@ -65,9 +72,25 @@ imap_hibernate_timeout = 15s
 # Host allowed in URLAUTH URLs sent by client. "*" allows all.
 #imap_urlauth_host =
 
+# Enable IMAP LITERAL- extension (replaces LITERAL+)
+#imap_literal_minus = no
+
+# What happens when FETCH fails due to some internal error:
+#   disconnect-immediately:
+#     The FETCH is aborted immediately and the IMAP client is disconnected.
+#   disconnect-after:
+#     The FETCH runs for all the requested mails returning as much data as
+#     possible. The client is finally disconnected without a tagged reply.
+#   no-after:
+#     Same as disconnect-after, but tagged NO reply is sent instead of
+#     disconnecting the client. If the client attempts to FETCH the same failed
+#     mail more than once, the client is disconnected. This is to avoid clients
+#     from going into infinite loops trying to FETCH a broken mail.
+#imap_fetch_failure = disconnect-immediately
+
 protocol imap {
   # Space separated list of plugins to load (default is global mail_plugins).
-  mail_plugins = $mail_plugins imap_stats imap_zlib
+  mail_plugins = $mail_plugins imap_zlib
 
   # Maximum number of IMAP connections allowed for a user from each IP address.
   # NOTE: The username is compared case-sensitively.
diff --git a/roles/IMAP/files/etc/dovecot/conf.d/90-plugin.conf b/roles/IMAP/files/etc/dovecot/conf.d/90-plugin.conf
index 9583b6d..52a81ca 100644
--- a/roles/IMAP/files/etc/dovecot/conf.d/90-plugin.conf
+++ b/roles/IMAP/files/etc/dovecot/conf.d/90-plugin.conf
@@ -23,11 +23,6 @@ plugin {
   quota = count:User quota
   quota_vsizes = yes
 
-  # how often to session statistics
-  stats_refresh = 30 secs
-  # track per-IMAP command statistics
-  stats_track_cmds = yes
-
   zlib_save = gz
   zlib_save_level = 6
 }
diff --git a/roles/IMAP/files/etc/dovecot/dovecot-dict-auth.conf.ext b/roles/IMAP/files/etc/dovecot/dovecot-dict-auth.conf.ext
index ecd7134..a054ffe 100644
--- a/roles/IMAP/files/etc/dovecot/dovecot-dict-auth.conf.ext
+++ b/roles/IMAP/files/etc/dovecot/dovecot-dict-auth.conf.ext
@@ -2,7 +2,7 @@
 # conf.d/auth-dict.conf.ext
 
 # Dictionary URI
-uri = proxy:/var/run/dovecot/auth-proxy:
+uri = proxy:/run/dovecot/auth-proxy:
 
 # Username iteration prefix. Keys under this are assumed to contain usernames.
 iterate_prefix = userdb/
diff --git a/roles/IMAP/files/etc/dovecot/dovecot-ldap.conf.ext b/roles/IMAP/files/etc/dovecot/dovecot-ldap.conf.ext
index 1b97a0e..a455616 100644
--- a/roles/IMAP/files/etc/dovecot/dovecot-ldap.conf.ext
+++ b/roles/IMAP/files/etc/dovecot/dovecot-ldap.conf.ext
@@ -130,7 +130,7 @@ pass_attrs =
 #pass_attrs = uid=user,userPassword=password,\
 #  homeDirectory=userdb_home,uidNumber=userdb_uid,gidNumber=userdb_gid
 
-# Filter for password lookups (ignored for auth binds)
+# Filter for password lookups
 pass_filter = (&(objectClass=FripostVirtualUser)(fvl=%n)(fripostIsStatusActive=TRUE))
 
 # Attributes and filter to get a list of all users
@@ -140,3 +140,12 @@ pass_filter = (&(objectClass=FripostVirtualUser)(fvl=%n)(fripostIsStatusActive=T
 # Default password scheme. "{scheme}" before password overrides this.
 # List of supported schemes is in: http://wiki2.dovecot.org/Authentication
 #default_pass_scheme = CRYPT
+
+# By default all LDAP lookups are performed by the auth master process.
+# If blocking=yes, auth worker processes are used to perform the lookups.
+# Each auth worker process creates its own LDAP connection so this can
+# increase parallelism. With blocking=no the auth master process can
+# keep 8 requests pipelined for the LDAP connection, while with blocking=yes
+# each connection has a maximum of 1 request running. For small systems the
+# blocking=no is sufficient and uses less resources.
+#blocking = no