Merge tag 'upstream/0.4' into debian

Upstream version 0.4

10 files changed, 230 insertions, 122 deletions

diff --git a/Changelog b/Changelog
index f2fee83..5a9074a 100644
--- a/Changelog
+++ b/Changelog
@@ -1,14 +1,29 @@
-interimap (0.4) UNRELEASED
+interimap (0.4) upstream;
 
   * pullimap: replace non RFC 5321-compliant envelope sender addresses
-    (received by the IMAP FETCH ENVELOPE command) by the null sender address
+    (received by the IMAP FETCH ENVELOPE command) with the null address
     <>.
+  * pullimap, interimap: take configuration filename (default: "config")
+    relative to $XDG_CONFIG_HOME/$NAME (or ~/.config/$NAME), to comply
+    with the XDG specification.  Thus the previous default config file
+    $XDG_CONFIG_HOME/$NAME should become $XDG_CONFIG_HOME/$NAME/config.
+  * Library: add support for TLSv1.3 (on recent enough Net::SSLeay), and
+    change "SSL_protocols" default value from "!SSLv2 !SSLv3" to "!SSLv2
+    !SSLv3 !TLSv1 !TLSv1.1".
   + Library: new API idle_start() and idle_stop().
   + Add support for untagged ESEARCH responses from RFC 4731.
+  + pullimap: Use extended SEARCH commands (RFC 4731) if supported by
+    the server to search old mail and EXPUNGE them.
+  + pullimap, interimap: don't autocreate statefile or database in
+    long-lived mode (when --watch or --idle is set).  Instead, an error
+    is raised if the statefile or database doesn't exist.
   - Ensure the lower bound of UID ranges is at least 1.
   - Fix manpage generation with pandoc >=2.1.
+  - Specify minimum Perl and Net::SSLeay versions.
+  - interimap.service: use --watch=60 rather than --notify, because
+    dovecot's NOTIFY extension doesn't seem to work so well as of 2.2.27.
 
- -- Guilhem Moulin <guilhem@guilhem.org>  Tue, 06 Dec 2016 17:37:01 +0100
+ -- Guilhem Moulin <guilhem@fripost.org>  Sun, 20 Jan 2019 20:30:08 +0100
 
 interimap (0.3) upstream;
 
@@ -31,7 +46,7 @@ interimap (0.3) upstream;
   - interimap: when resuming a sync, only consider UIDs greater than a
     known UIDNEXT.
 
- -- Guilhem Moulin <guilhem@guilhem.org>  Thu, 01 Dec 2016 14:37:50 +0100
+ -- Guilhem Moulin <guilhem@fripost.org>  Thu, 01 Dec 2016 14:37:50 +0100
 
 interimap (0.2) upstream;
 
@@ -65,10 +80,10 @@ interimap (0.2) upstream;
   * Display source UIDs upon APPEND.  Previously only target UIDs where
     displayed in non-debug mode.
 
- -- Guilhem Moulin <guilhem@guilhem.org>  Wed, 09 Sep 2015 00:44:35 +0200
+ -- Guilhem Moulin <guilhem@fripost.org>  Wed, 09 Sep 2015 00:44:35 +0200
 
 interimap (0.1) upstream;
 
   * Initial public release.  Development was started in July 2015.
 
- -- Guilhem Moulin <guilhem@guilhem.org>  Mon, 07 Sep 2015 17:14:42 +0200
+ -- Guilhem Moulin <guilhem@fripost.org>  Mon, 07 Sep 2015 17:14:42 +0200
diff --git a/INSTALL b/INSTALL
index 458b7c2..69afb26 100644
--- a/INSTALL
+++ b/INSTALL
@@ -1,4 +1,4 @@
-InterIMAP depends on the following Perl modules:
+InterIMAP depends on Perl >=5.20 and the following Perl modules:
 
   - Compress::Raw::Zlib (core module)
   - Config::Tiny
@@ -8,7 +8,7 @@ InterIMAP depends on the following Perl modules:
   - Getopt::Long (core module)
   - MIME::Base64 (core module) if authentication is required
   - List::Util (core module)
-  - Net::SSLeay
+  - Net::SSLeay >=1.73
   - POSIX (core module)
   - Socket (core module)
   - Time::HiRes (core module) if 'logfile' is set
diff --git a/README b/README
index 6c3ae34..06f328f 100644
--- a/README
+++ b/README
@@ -1,6 +1,6 @@
 InterIMAP is a fast bidirectional synchronization program for QRESYNC-capable
 IMAP4rev1 servers.  PullIMAP retrieves messages a remote IMAP mailbox and
-deliver them to a SMTP session.  Consult the manuals for more information.
+deliver them to an SMTP session.  Consult the manuals for more information.
 
     https://guilhem.org/man/interimap.1.html
     https://guilhem.org/man/pullimap.1.html
@@ -52,7 +52,7 @@ the AUTHENTICATE command.  For instance the following configuration
 snippet saves bandwidth and brings a significant speed gain compared to
 type=imaps.
 
-    local: $XDG_CONFIG_HOME/interimap:
+    local: $XDG_CONFIG_HOME/interimap/config:
       [remote]
       type = tunnel
       command = /usr/bin/ssh user@imap.example.net
@@ -82,6 +82,6 @@ usage with regular INET sockets (type=imaps or type=imap).
 
 _______________________________________________________________________
 
-InterIMAP is Copyright© 2015 Guilhem Moulin ⟨guilhem@fripost.org⟩, and
-licensed for use under the GNU General Public License version 3 or
+InterIMAP is Copyright© 2015-2018 Guilhem Moulin ⟨guilhem@fripost.org⟩,
+and licensed for use under the GNU General Public License version 3 or
 later.  See ‘COPYING’ for specific terms and distribution information.
diff --git a/interimap b/interimap
index 049b564..454d311 100755
--- a/interimap
+++ b/interimap
@@ -2,7 +2,7 @@
 
 #----------------------------------------------------------------------
 # Fast bidirectional synchronization for QRESYNC-capable IMAP servers
-# Copyright © 2015,2016 Guilhem Moulin <guilhem@fripost.org>
+# Copyright © 2015-2018 Guilhem Moulin <guilhem@fripost.org>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -18,19 +18,21 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #----------------------------------------------------------------------
 
+use v5.14.2;
 use strict;
 use warnings;
 
-our $VERSION = '0.3';
+our $VERSION = '0.4';
 my $NAME = 'interimap';
 use Getopt::Long qw/:config posix_default no_ignore_case gnu_compat
                             bundling auto_version/;
 use DBI ();
+use DBD::SQLite::Constants ':file_open';
 use Fcntl qw/F_GETFD F_SETFD FD_CLOEXEC/;
 use List::Util 'first';
 
 use lib 'lib';
-use Net::IMAP::InterIMAP qw/read_config compact_set/;
+use Net::IMAP::InterIMAP 0.0.4 qw/xdg_basedir read_config compact_set/;
 
 # Clean up PATH
 $ENV{PATH} = join ':', qw{/usr/bin /bin};
@@ -63,20 +65,24 @@ my $COMMAND = do {
 };
 usage(1) if defined $COMMAND and (($COMMAND eq 'delete' and !@ARGV) or ($COMMAND eq 'rename' and $#ARGV != 1));
 usage(1) if defined $COMMAND and (defined $CONFIG{watch} or defined $CONFIG{notify});
-usage(1) if $CONFIG{target} and !(defined $COMMAND and ($COMMAND eq 'delete'or $COMMAND eq 'rename'));
+usage(1) if $CONFIG{target} and !(defined $COMMAND and ($COMMAND eq 'delete' or $COMMAND eq 'rename'));
 $CONFIG{watch} = $CONFIG{notify} ? 900 : 60 if (defined $CONFIG{watch} or $CONFIG{notify}) and !$CONFIG{watch};
 @ARGV = map {uc $_ eq 'INBOX' ? 'INBOX' : $_ } @ARGV; # INBOX is case-insensitive
 die "Invalid mailbox name $_" foreach grep !/\A([\x01-\x7F]+)\z/, @ARGV;
 
 
-my $CONF = read_config( delete $CONFIG{config} // $NAME
-                      , [qw/_ local remote/]
-                      , database => qr/\A(\P{Control}+)\z/
-                      , logfile => qr/\A(\/\P{Control}+)\z/
-                      , 'list-mailbox' => qr/\A([\x01-\x09\x0B\x0C\x0E-\x7F]+)\z/
-                      , 'list-select-opts' => qr/\A([\x21\x23\x24\x26\x27\x2B-\x5B\x5E-\x7A\x7C-\x7E]+)\z/
-                      , 'ignore-mailbox' => qr/\A([\x01-\x09\x0B\x0C\x0E-\x7F]+)\z/
-                      );
+my $CONF = do {
+    my $conffile = delete($CONFIG{config}) // "config";
+    $conffile = xdg_basedir( XDG_CONFIG_HOME => ".config", $NAME, $conffile );
+    read_config( $conffile
+               , [qw/_ local remote/]
+               , database => qr/\A(\P{Control}+)\z/
+               , logfile => qr/\A(\/\P{Control}+)\z/
+               , 'list-mailbox' => qr/\A([\x01-\x09\x0B\x0C\x0E-\x7F]+)\z/
+               , 'list-select-opts' => qr/\A([\x21\x23\x24\x26\x27\x2B-\x5B\x5E-\x7A\x7C-\x7E]+)\z/
+               , 'ignore-mailbox' => qr/\A([\x01-\x09\x0B\x0C\x0E-\x7F]+)\z/
+               );
+};
 my ($DBFILE, $LOGGER_FD);
 
 {
@@ -84,16 +90,7 @@ my ($DBFILE, $LOGGER_FD);
     $DBFILE //= $CONF->{remote}->{host}.'.db' if defined $CONF->{remote};
     $DBFILE //= $CONF->{local}->{host}. '.db' if defined $CONF->{local};
     die "Missing option database" unless defined $DBFILE;
-
-    unless ($DBFILE =~ /\A\//) {
-        my $dir = ($ENV{XDG_DATA_HOME} // "$ENV{HOME}/.local/share") .'/'. $NAME;
-        $dir =~ /\A(\/\p{Print}+)\z/ or die "Insecure $dir";
-        $dir = $1;
-        $DBFILE = $dir .'/'. $DBFILE;
-        unless (-d $dir) {
-            mkdir $dir, 0700 or die "Can't mkdir $dir: $!\n";
-        }
-    }
+    $DBFILE = xdg_basedir( XDG_DATA_HOME => ".local/share", $NAME, $DBFILE );
 
     if (defined $CONF->{_} and defined $CONF->{_}->{logfile}) {
         require 'POSIX.pm';
@@ -125,18 +122,24 @@ $SIG{TERM} = sub { cleanup(); exit 0; };
 #############################################################################
 # Open the database and create tables
 
-$DBH = DBI::->connect("dbi:SQLite:dbname=$DBFILE", undef, undef, {
-    AutoCommit => 0,
-    RaiseError => 1,
-    sqlite_see_if_its_a_number => 1, # see if the bind values are numbers or not
-    sqlite_use_immediate_transaction => 1,
-});
-$DBH->sqlite_busy_timeout(250);
-$DBH->do('PRAGMA locking_mode = EXCLUSIVE');
-$DBH->do('PRAGMA foreign_keys = ON');
-
 
 {
+    my $dbi_data_source = "dbi:SQLite:dbname=".$DBFILE;
+    my %dbi_attrs = (
+        AutoCommit => 0,
+        RaiseError => 1,
+        sqlite_see_if_its_a_number => 1, # see if the bind values are numbers or not
+        sqlite_use_immediate_transaction => 1,
+        sqlite_open_flags => SQLITE_OPEN_READWRITE
+    );
+    # don't auto-create in long-lived mode
+    $dbi_attrs{sqlite_open_flags} |= SQLITE_OPEN_CREATE unless defined $CONFIG{watch};
+
+    $DBH = DBI::->connect($dbi_data_source, undef, undef, \%dbi_attrs);
+    $DBH->sqlite_busy_timeout(250);
+    $DBH->do('PRAGMA locking_mode = EXCLUSIVE');
+    $DBH->do('PRAGMA foreign_keys = ON');
+
     my @schema = (
         mailboxes => [
             q{idx        INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT},
@@ -166,6 +169,10 @@ $DBH->do('PRAGMA foreign_keys = ON');
             # also, lUID  < local.UIDNEXT and rUID < remote.UIDNEXT (except for interrupted syncs)
             # mapping.idx must be found among local.idx (and remote.idx)
         ],
+
+        # We have no version number in the schema, but if we ever need a
+        # migration, we'll add a new table, and assume version 1.0 if
+        # the table is missing.
     );
 
     # Invariants:
diff --git a/interimap.md b/interimap.md
index 4a321f1..4d85eaf 100644
--- a/interimap.md
+++ b/interimap.md
@@ -140,8 +140,8 @@ Options
 `--config=`*FILE*
 
 :   Specify an alternate [configuration file](#configuration-file).
-    Relative paths start from *$XDG_CONFIG_HOME*, or *~/.config* if the
-    `XDG_CONFIG_HOME` environment variable is unset.
+    Relative paths start from *$XDG_CONFIG_HOME/interimap*, or *~/.config/interimap*
+    if the `XDG_CONFIG_HOME` environment variable is unset.
 
 `--target={local,remote,database}`
 
@@ -192,9 +192,9 @@ Configuration file
 ==================
 
 Unless told otherwise by the `--config=FILE` command-line option,
-`interimap` reads its configuration from *$XDG_CONFIG_HOME/interimap*
-(or *~/.config/interimap* if the `XDG_CONFIG_HOME` environment variable
-is unset) as an [INI file].
+`interimap` reads its configuration from *$XDG_CONFIG_HOME/interimap/config*
+(or *~/.config/interimap/config* if the `XDG_CONFIG_HOME` environment
+variable is unset) as an [INI file].
 The syntax of the configuration file is a series of `OPTION=VALUE`
 lines organized under some `[SECTION]`; lines starting with a ‘#’ or
 ‘;’ character are ignored as comments.
@@ -332,9 +332,10 @@ Valid options are:
 
 :   A space-separated list of SSL protocols to enable or disable (if
     prefixed with an exclamation mark `!`.  Known protocols are `SSLv2`,
-    `SSLv3`, `TLSv1`, `TLSv1.1`, and `TLSv1.2`.  Enabling a protocol is
-    a short-hand for disabling all other protocols.
-    (Default: `!SSLv2 !SSLv3`, i.e., only enable TLSv1 and above.)
+    `SSLv3`, `TLSv1`, `TLSv1.1`, `TLSv1.2`, and `TLSv1.3`.  Enabling a
+    protocol is a short-hand for disabling all other protocols.
+    (Default: `!SSLv2 !SSLv3 !TLSv1 !TLSv1.1`, i.e., only enable TLSv1.2
+    and above.)
 
 *SSL_cipher_list*
 
@@ -398,7 +399,9 @@ Known bugs and limitations
 
  * Using `interimap` on two identical servers with a non-existent or
    empty *database* will duplicate each message due to the absence of
-   local ↔ remote UID association.
+   local ↔ remote UID association.  Hence one needs to manually empty
+   the mail store on one end when migrating to `interimap` from another
+   synchronisation solution.
 
  * `interimap` is single threaded and doesn't use IMAP command
    pipelining.  Synchronization could be boosted up by sending
diff --git a/interimap.sample b/interimap.sample
index 8cd0a29..f771e54 100644
--- a/interimap.sample
+++ b/interimap.sample
@@ -1,4 +1,4 @@
-#database = imap.guilhem.org.db
+#database = imap.example.org.db
 #list-mailbox = "*"
 list-select-opts = SUBSCRIBED
 ignore-mailbox = ^virtual/
diff --git a/interimap.service b/interimap.service
index 6e487d4..8e9915f 100644
--- a/interimap.service
+++ b/interimap.service
@@ -4,7 +4,7 @@ Wants=network-online.target
 After=network-online.target
 
 [Service]
-ExecStart=/usr/bin/interimap --notify
+ExecStart=/usr/bin/interimap --watch=60
 RestartSec=10min
 Restart=on-failure
 
diff --git a/lib/Net/IMAP/InterIMAP.pm b/lib/Net/IMAP/InterIMAP.pm
index 3270108..a773f08 100644
--- a/lib/Net/IMAP/InterIMAP.pm
+++ b/lib/Net/IMAP/InterIMAP.pm
@@ -1,6 +1,6 @@
 #----------------------------------------------------------------------
 # A minimal IMAP4 client for QRESYNC-capable servers
-# Copyright © 2015 Guilhem Moulin <guilhem@fripost.org>
+# Copyright © 2015-2018 Guilhem Moulin <guilhem@fripost.org>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -16,15 +16,15 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #----------------------------------------------------------------------
 
-package Net::IMAP::InterIMAP v0.0.3;
+package Net::IMAP::InterIMAP v0.0.4;
 use warnings;
 use strict;
 
 use Compress::Raw::Zlib qw/Z_OK Z_FULL_FLUSH Z_SYNC_FLUSH MAX_WBITS/;
 use Config::Tiny ();
-use Errno 'EINTR';
+use Errno qw/EEXIST EINTR/;
 use Fcntl qw/F_GETFD F_SETFD FD_CLOEXEC/;
-use Net::SSLeay ();
+use Net::SSLeay 1.73 ();
 use List::Util qw/all first/;
 use POSIX ':signal_h';
 use Socket qw/SOCK_STREAM IPPROTO_TCP AF_INET AF_INET6 SOCK_RAW :addrinfo/;
@@ -35,7 +35,7 @@ BEGIN {
     Net::SSLeay::SSLeay_add_ssl_algorithms();
     Net::SSLeay::randomize();
 
-    our @EXPORT_OK = qw/read_config compact_set $IMAP_text $IMAP_cond
+    our @EXPORT_OK = qw/xdg_basedir read_config compact_set $IMAP_text $IMAP_cond
                         slurp is_dirty has_new_mails/;
 }
 
@@ -45,7 +45,7 @@ my $RE_ATOM_CHAR    = qr/[\x21\x23\x24\x26\x27\x2B-\x5B\x5E-\x7A\x7C-\x7E]/;
 my $RE_ASTRING_CHAR = qr/[\x21\x23\x24\x26\x27\x2B-\x5B\x5D-\x7A\x7C-\x7E]/;
 my $RE_TEXT_CHAR    = qr/[\x01-\x09\x0B\x0C\x0E-\x7F]/;
 
-my $RE_SSL_PROTO = qr/(?:SSLv[23]|TLSv1|TLSv1\.[0-2])/;
+my $RE_SSL_PROTO = qr/(?:SSLv[23]|TLSv1|TLSv1\.[0-3])/;
 
 # Map each option to a regexp validating its values.
 my %OPTIONS = (
@@ -76,6 +76,35 @@ my $CRLF = "\x0D\x0A";
 #############################################################################
 # Utilities
 
+# xdg_basedir($xdg_variable, $default, $subdir, $path)
+#   Return $path if $path is absolute.  Otherwise, return
+#   "$ENV{$xdg_variable}/$subdir/$path" (resp. "~/$default/$subdir/path"
+#   if the "$xdg_variable" environment variable is not set).
+#   An error is raised if "$ENV{$xdg_variable}" (resp. "~/$default") is
+#   not an existing absolute directory.
+#   If "$ENV{$xdg_variable}/$subdir" doesn't exist, it is created with
+#   mode 0700.
+sub xdg_basedir($$$$) {
+    my ($xdg_variable, $default, $subdir, $path) = @_;
+    $path =~ /\A(\p{Print}+)\z/ or die "Insecure $path";
+    $path = $1;
+    return $path if $path =~ /\A\//;
+
+    my $basedir = $ENV{$xdg_variable};
+    unless (defined $basedir) {
+        my @getent = getpwuid($>);
+        $basedir = $getent[7] ."/". $default;
+    }
+    die "No such directory: ", $basedir unless -d $basedir;
+    $basedir .= "/".$subdir;
+    $basedir =~ /\A(\/\p{Print}+)\z/ or die "Insecure $basedir";
+    $basedir = $1;
+    unless (mkdir ($basedir, 0700)) {
+        die "Couldn't create $basedir: $!\n" unless $! == EEXIST;
+    }
+    return $basedir ."/". $path;
+}
+
 # read_config($conffile, $sections, %opts)
 #   Read $conffile's default section, then each section in the array
 #   reference $section (which takes precedence).  %opts extends %OPTIONS
@@ -85,9 +114,6 @@ sub read_config($$%) {
     my $sections = shift;
     my %opts = (%OPTIONS, @_);
 
-    $conffile = ($ENV{XDG_CONFIG_HOME} // "$ENV{HOME}/.config") .'/'. $conffile
-        unless $conffile =~ /\A\//; # relative path
-
     die "No such config file $conffile\n"
         unless defined $conffile and -f $conffile and -r $conffile;
 
@@ -597,7 +623,7 @@ sub incapable($@) {
 #   Issue an UID SEARCH command with the given $criterion.  For the "normal"
 #   UID SEARCH command from RFC 3501, return the list of matching UIDs;
 #   for the extended UID SEARCH command from RFC 4731 (ensuring ESEARCH
-#   capability is the caller's responsibility), return an "UID"
+#   capability is the caller's responsibility), return an optional "UID"
 #   indicator followed by a hash containing search data pairs.
 sub search($$) {
     my ($self, $crit) = @_;
@@ -1573,13 +1599,19 @@ sub _ssl_verify($$$) {
     return $ok; # 1=accept cert, 0=reject
 }
 
-my %SSL_proto = (
-    'SSLv2' => Net::SSLeay::OP_NO_SSLv2(),
-    'SSLv3' => Net::SSLeay::OP_NO_SSLv3(),
-    'TLSv1' => Net::SSLeay::OP_NO_TLSv1(),
-    'TLSv1.1' => Net::SSLeay::OP_NO_TLSv1_1(),
-    'TLSv1.2' => Net::SSLeay::OP_NO_TLSv1_2()
-);
+my %SSL_proto;
+BEGIN {
+    sub _append_ssl_proto($$) {
+        my ($k, $v) = @_;
+        $SSL_proto{$k} = $v if defined $v;
+    }
+    _append_ssl_proto( "SSLv2",   eval { Net::SSLeay::OP_NO_SSLv2()   } );
+    _append_ssl_proto( "SSLv3",   eval { Net::SSLeay::OP_NO_SSLv3()   } );
+    _append_ssl_proto( "TLSv1",   eval { Net::SSLeay::OP_NO_TLSv1()   } );
+    _append_ssl_proto( "TLSv1.1", eval { Net::SSLeay::OP_NO_TLSv1_1() } );
+    _append_ssl_proto( "TLSv1.2", eval { Net::SSLeay::OP_NO_TLSv1_2() } );
+    _append_ssl_proto( "TLSv1.3", eval { Net::SSLeay::OP_NO_TLSv1_3() } );
+}
 
 # $self->_start_ssl($socket)
 #   Upgrade the $socket to SSL/TLS.
@@ -1588,7 +1620,7 @@ sub _start_ssl($$) {
     my $ctx = Net::SSLeay::CTX_new() or $self->panic("Failed to create SSL_CTX $!");
     my $ssl_options = Net::SSLeay::OP_SINGLE_DH_USE() | Net::SSLeay::OP_SINGLE_ECDH_USE();
 
-    $self->{SSL_protocols} //= q{!SSLv2 !SSLv3};
+    $self->{SSL_protocols} //= q{!SSLv2 !SSLv3 !TLSv1 !TLSv1.1};
     my ($proto_include, $proto_exclude) = (0, 0);
     foreach (split /\s+/, $self->{SSL_protocols}) {
         my $neg = s/^!// ? 1 : 0;
@@ -1603,7 +1635,7 @@ sub _start_ssl($$) {
         $proto_exclude |= $x;
     }
     my @proto_exclude = grep { ($proto_exclude & $SSL_proto{$_}) != 0 } keys %SSL_proto;
-    $self->log("Disabling SSL protocol: ".join(', ', sort @proto_exclude)) if $self->{debug};
+    $self->log("Disabling SSL protocols: ".join(', ', sort @proto_exclude)) if $self->{debug};
     $ssl_options |= $SSL_proto{$_} foreach @proto_exclude;
     $ssl_options |= Net::SSLeay::OP_NO_COMPRESSION();
 
@@ -1649,6 +1681,7 @@ sub _start_ssl($$) {
                                                        $v == 0x0301 ? 'TLSv1' :
                                                        $v == 0x0302 ? 'TLSv1.1' :
                                                        $v == 0x0303 ? 'TLSv1.2' :
+                                                       $v == 0x0304 ? 'TLSv1.3' :
                                                                       '??'),
                                                       $v));
         $self->log(sprintf('SSL cipher: %s (%d bits)'
@@ -1946,7 +1979,7 @@ sub _send($$;&) {
     }
     else {
         my $set = $$command =~ /\AUID (?:FETCH|STORE) ([0-9:,*]+)/ ? $1
-                : $$command =~ /\AUID SEARCH / ? "\"$tag\"" # RFC 4466's tag-string
+                : $$command =~ /\AUID SEARCH / ? $tag # for RFC 4466's tag-string
                 : undef;
         $self->_recv($tag, $callback, $cmd, $set);
     }
@@ -2234,6 +2267,21 @@ sub _envelope($$) {
     return \@envelope;
 }
 
+# Parse and consume an RFC 4466 tagged-ext-comp plus a trailing parenthesis
+sub _tagged_ext_comp($$$) {
+    my ($self, $stream, $ret) = @_;
+    my $v = $$stream =~ s/\A\(// ? $self->_tagged_ext_comp(\$_, [])
+          : $self->_astring(\$_);
+    push @$ret, $v;
+    if ($$stream =~ s/\A\)//) {
+        return $ret;
+    } elsif ($$stream =~ s/\A //) {
+        $self->_tagged_ext_comp(\$_, $ret)
+    } else {
+        $self->panic($$stream);
+    }
+}
+
 # $self->_resp($buf, [$callback, $cmd, $set] )
 #   Parse an untagged response line or a continuation request line.
 #   (The trailing CRLF must be removed.)  The internal cache is
@@ -2288,16 +2336,30 @@ sub _resp($$;&$$) {
         elsif (/\ASEARCH((?: [0-9]+)*)\z/) {
             $callback->(split(/ /, ($1 =~ s/^ //r))) if defined $callback and $cmd eq 'SEARCH';
         }
-        elsif (defined $set and s/\AESEARCH \(TAG \Q$set\E\)( UID)?//) {
-            my $uid = $1;
-            my %ret; # RFC 4731
+        elsif (s/\AESEARCH( |\z)/$1/) {
+            my $tag = $1 if s/\A \(TAG \"($RE_ASTRING_CHAR+)\"\)//;
+            my $uid = s/\A UID// ? "UID" : undef;
+            my @ret;
             while ($_ ne '') {
-                $self->fail("RFC 4731 violation in ESEARCH response")
-                    # XXX RFC 4466's tagged-ext-comp unsupported
-                    unless s/\A ($RE_ATOM_CHAR+) ([0-9,:]+)//;
-                $ret{uc $1} = $2;
+                # RFC 4466 "tagged-ext-label" is a valid RFC 3501 "atom"
+                s/\A ($RE_ATOM_CHAR+) // or $self->panic();
+                my $label = uc($1);
+                my $value;
+                if (s/\A([0-9,:]+)//) {
+                    # RFC 4466 tagged-ext-simple
+                    $value = $1;
+                } elsif (s/\A\(//) {
+                    # RFC 4466 "(" [tagged-ext-comp] ")"
+                    $value = s/\A\)// ? [] : $self->_tagged_ext_comp(\$_, []);
+                } else {
+                    $self->panic();
+                }
+                # don't use a hash since some extensions might give more
+                # than one response for a same key
+                push @ret, $label => $value;
             }
-            $callback->($uid, %ret) if defined $callback and $cmd eq 'SEARCH';
+            $callback->($uid, @ret) if defined $callback and $cmd eq 'SEARCH'
+                and defined $set and $set eq $tag;
         }
         elsif (s/\ALIST \((\\?$RE_ATOM_CHAR+(?: \\?$RE_ATOM_CHAR+)*)?\) ("(?:\\[\x22\x5C]|[\x01-\x09\x0B\x0C\x0E-\x21\x23-\x5B\x5D-\x7F])"|NIL) //) {
             my ($delim, $attrs) = ($2, $1);
@@ -2306,7 +2368,7 @@ sub _resp($$;&$$) {
             $self->panic($_) unless $_ eq '';
             $mailbox = 'INBOX' if uc $mailbox eq 'INBOX'; # INBOX is case-insensitive
             undef $delim if uc $delim eq 'NIL';
-            $delim =~ s/\A"(.*)"\Z/$1/ if defined $delim;
+            $delim =~ s/\A"(.*)"\z/$1/ if defined $delim;
             $self->_update_cache_for($mailbox, DELIMITER => $delim);
             $self->_update_cache_for($mailbox, LIST_ATTRIBUTES => \@attrs);
             $callback->($mailbox, $delim, @attrs) if defined $callback and $cmd eq 'LIST';
diff --git a/pullimap b/pullimap
index dca8c49..495b99e 100755
--- a/pullimap
+++ b/pullimap
@@ -2,7 +2,7 @@
 
 #----------------------------------------------------------------------
 # Pull mails from an IMAP mailbox and deliver them to a SMTP session
-# Copyright © 2016 Guilhem Moulin <guilhem@fripost.org>
+# Copyright © 2016-2018 Guilhem Moulin <guilhem@fripost.org>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -21,7 +21,8 @@
 use strict;
 use warnings;
 
-our $VERSION = '0.3';
+use v5.20.2;
+our $VERSION = '0.4';
 my $NAME = 'pullimap';
 
 use Errno 'EINTR';
@@ -31,7 +32,7 @@ use List::Util 'first';
 use Socket qw/PF_INET PF_INET6 SOCK_STREAM/;
 
 use lib 'lib';
-use Net::IMAP::InterIMAP qw/read_config compact_set/;
+use Net::IMAP::InterIMAP 0.0.4 qw/xdg_basedir read_config compact_set/;
 
 # Clean up PATH
 $ENV{PATH} = join ':', qw{/usr/bin /bin};
@@ -59,15 +60,19 @@ usage(1) unless $#ARGV == 0 and $ARGV[0] ne '_';
 #######################################################################
 # Read and validate configuration
 #
-my $CONF = read_config( delete $CONFIG{config} // $NAME,
-                      , [$ARGV[0]]
-                      , statefile => qr/\A(\P{Control}+)\z/
-                      , mailbox => qr/\A([\x01-\x7F]+)\z/
-                      , 'deliver-method' => qr/\A([ls]mtp:\[.*\]:\d+)\z/
-                      , 'deliver-ehlo' => qr/\A(\P{Control}+)\z/
-                      , 'deliver-rcpt' => qr/\A(\P{Control}+)\z/
-                      , 'purge-after' => qr/\A(\d*)\z/
-                      )->{$ARGV[0]};
+my $CONF = do {
+    my $conffile = delete($CONFIG{config}) // "config";
+    $conffile = xdg_basedir( XDG_CONFIG_HOME => ".config", $NAME, $conffile );
+    read_config( $conffile
+               , [$ARGV[0]]
+               , statefile => qr/\A(\P{Control}+)\z/
+               , mailbox => qr/\A([\x01-\x7F]+)\z/
+               , 'deliver-method' => qr/\A([ls]mtp:\[.*\]:\d+)\z/
+               , 'deliver-ehlo' => qr/\A(\P{Control}+)\z/
+               , 'deliver-rcpt' => qr/\A(\P{Control}+)\z/
+               , 'purge-after' => qr/\A(\d*)\z/
+               )->{$ARGV[0]};
+};
 
 my ($MAILBOX, $STATE);
 do {
@@ -75,23 +80,23 @@ do {
 
     my $statefile = $CONF->{statefile} // $ARGV[0];
     die "Missing option statefile" unless defined $statefile;
-    $statefile = $statefile =~ /\A(\p{Print}+)\z/ ? $1 : die "Insecure $statefile";
-
-    unless ($statefile =~ /\A\//) {
-        my $dir = ($ENV{XDG_DATA_HOME} // "$ENV{HOME}/.local/share") .'/'. $NAME;
-        $dir = $dir =~ /\A(\/\p{Print}+)\z/ ? $1 : die "Insecure $dir";
-        $statefile = $dir .'/'. $statefile;
-        unless (-d $dir) {
-            mkdir $dir, 0700 or die "Can't mkdir $dir: $!\n";
-        }
-    }
+    $statefile = xdg_basedir( XDG_DATA_HOME => ".local/share", $NAME, $statefile );
+
+    my $mode = O_RDWR | O_DSYNC;
+    # don't auto-create in long-lived mode
+    $mode |= O_CREAT unless defined $CONFIG{idle};
 
-    sysopen($STATE, $statefile, O_CREAT|O_RDWR|O_DSYNC, 0600) or die "Can't open $statefile: $!";
+    sysopen($STATE, $statefile, $mode, 0600) or die "Can't open $statefile: $!";
     # XXX we need to pack the struct flock manually: not portable!
     my $struct_flock = pack('s!s!l!l!i!', F_WRLCK, SEEK_SET, 0, 0, 0);
     fcntl($STATE, F_SETLK, $struct_flock) or die "Can't lock $statefile: $!";
     my $flags = fcntl($STATE, F_GETFD, 0)       or die "fcntl F_GETFD: $!";
     fcntl($STATE, F_SETFD, $flags | FD_CLOEXEC) or die "fcntl F_SETFD: $!";
+
+    # We have no version number in the statefile, but if we ever need a
+    # migration, we'll add a 1-byte header for the version number, and
+    # assume version 1.0 if the size of the file is a multiple of 4
+    # bytes. (We can also use the fact that bytes 5 to 8 are never all 0.)
 };
 
 
@@ -249,10 +254,20 @@ sub purge() {
         my @now = gmtime($now - $days*86400);
         my @m = qw/Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec/; # RFC 3501's date-month
         my $date = sprintf("%02d-%s-%04d", $now[3], $m[$now[4]], $now[5]+1900);
-        my @uid = $IMAP->search("UID $set BEFORE $date");
-
-        $set = @uid ? compact_set(@uid) : undef;
-        $IMAP->log("Removing ".($#uid+1)." UID(s) $set") if defined $set and !$CONFIG{quiet};
+        my $ext = $IMAP->incapable('ESEARCH') ? undef : [qw/COUNT ALL/];
+        my @uid = $IMAP->search((defined $ext ? "RETURN (".join(' ', @$ext).') ' : '')
+                                ."UID $set BEFORE $date");
+        my $count;
+        if (defined $ext) {
+            my ($uid_indicator, %resp) = @uid;
+            $IMAP->panic() unless defined $uid_indicator and $uid_indicator = 'UID';
+            $count = $resp{COUNT} // $IMAP->panic();
+            $set = $resp{ALL}; # MUST NOT be present if there are no matches
+        } else {
+            $count = $#uid+1;
+            $set = $count == 0 ? undef : compact_set(@uid);
+        }
+        $IMAP->log("Removing $count UID(s) $set") if $count > 0 and !$CONFIG{quiet};
     }
 
     if (defined $set) {
diff --git a/pullimap.md b/pullimap.md
index cb2a07a..a367dd1 100644
--- a/pullimap.md
+++ b/pullimap.md
@@ -32,8 +32,8 @@ Options
 `--config=`*FILE*
 
 :   Specify an alternate [configuration file](#configuration-file).
-    Relative paths start from *$XDG_CONFIG_HOME*, or *~/.config* if the
-    `XDG_CONFIG_HOME` environment variable is unset.
+    Relative paths start from *$XDG_CONFIG_HOME/pullimap*, or *~/.config/pullimap*
+    if the `XDG_CONFIG_HOME` environment variable is unset.
 
 `--idle`[`=`*seconds*]
 
@@ -74,9 +74,9 @@ Configuration file
 ==================
 
 Unless told otherwise by the `--config=FILE` command-line option,
-`pullimap` reads its configuration from *$XDG_CONFIG_HOME/pullimap* (or
-*~/.config/pullimap* if the `XDG_CONFIG_HOME` environment variable is
-unset) as an [INI file].
+`pullimap` reads its configuration from *$XDG_CONFIG_HOME/pullimap/config*
+(or *~/.config/pullimap/config* if the `XDG_CONFIG_HOME` environment variable
+is unset) as an [INI file].
 The syntax of the configuration file is a series of `OPTION=VALUE`
 lines organized under some `[SECTION]`; lines starting with a ‘#’ or
 ‘;’ character are ignored as comments.
@@ -121,9 +121,10 @@ Valid options are:
     the IMAP server.  (The value is at best 24h accurate due to the IMAP
     `SEARCH` criterion ignoring time and timezone.)
     If *purge-after* is set to `0` then messages are deleted immediately
-    after delivery.  Otherwise `pullimap` issues an IMAP `SEARCH`
-    command to list old messages; if `--idle` is set then the `SEARCH`
-    command is issued again every 12 hours.
+    after delivery.  Otherwise `pullimap` issues an IMAP `SEARCH` (or
+    extended `SEARCH` on servers advertizing the [`ESEARCH`][RFC 4731]
+    capability) command to list old messages; if `--idle` is set then
+    the `SEARCH` command is issued again every 12 hours.
 
 *type*
 
@@ -197,9 +198,10 @@ Valid options are:
 
 :   A space-separated list of SSL protocols to enable or disable (if
     prefixed with an exclamation mark `!`.  Known protocols are `SSLv2`,
-    `SSLv3`, `TLSv1`, `TLSv1.1`, and `TLSv1.2`.  Enabling a protocol is
-    a short-hand for disabling all other protocols.
-    (Default: `!SSLv2 !SSLv3`, i.e., only enable TLSv1 and above.)
+    `SSLv3`, `TLSv1`, `TLSv1.1`, `TLSv1.2`, and `TLSv1.3`.  Enabling a
+    protocol is a short-hand for disabling all other protocols.
+    (Default: `!SSLv2 !SSLv3 !TLSv1 !TLSv1.1`, i.e., only enable TLSv1.2
+    and above.)
 
 *SSL_cipher_list*
 
@@ -339,6 +341,9 @@ Standards
    [RFC 4315], December 2005.
  * A. Gulbrandsen, _The IMAP `COMPRESS` Extension_,
    [RFC 4978], August 2007.
+ * A. Melnikov and D. Cridland, _IMAP4 Extension to SEARCH Command for
+   Controlling What Kind of Information Is Returned_,
+   [RFC 4731], November 2006.
  * R. Siemborski and A. Gulbrandsen, _IMAP Extension for Simple
    Authentication and Security Layer (SASL) Initial Client Response_,
    [RFC 4959], September 2007.
@@ -358,6 +363,7 @@ Standards
 [RFC 4978]: https://tools.ietf.org/html/rfc4978
 [RFC 1928]: https://tools.ietf.org/html/rfc1928
 [RFC 1929]: https://tools.ietf.org/html/rfc1929
+[RFC 4731]: https://tools.ietf.org/html/rfc4731
 
 [INI file]: https://en.wikipedia.org/wiki/INI_file
 [`fetchmail`(1)]: http://www.fetchmail.info/