This version fixes a couple of processing bugs in the new header
blacklist filter and an access violation that can lead to crashes.
The header blacklist should is [sic] safe to enable now.
This version adds the ability to filter messages based on the content
of their headers. Please note that enabling this feature should
be accompanied by disabling the use of the "softlimit" program. In
addition to fixing some small bugs and a compiling error on Debian
7, it also fixes a series of major bugs that could lead to buffer
overflows. Depending on spamdyke's configuration, these could cause
remotely exploitable security holes. Please upgrade immediately!
Looks like there's a bug in the header blacklist filter. Don't
enable that filter yet.
Fixed config-test message for a graylist domain folder when the domain is not
in the list of local domains from ERROR to INFO. Thanks to Eric Shubert
for reporting this one.
Fixed a bunch of copy-and-paste errors in the option_list array in
prepare_settings() where options were designated
CONFIG_TYPE_STRING_SINGLETON instead of CONFIG_TYPE_OPTION_SINGLETON or
CONFIG_TYPE_STRING_ARRAY instead of CONFIG_TYPE_OPTION_ARRAY.
Fixed configure script errors and compilation warnings on Debian 7, which
enables the new GCC flags -Waddress and -Wunused-but-set-variable by
default. Thanks to Steve Cole for reporting this one.
Added some explanitory comments to spamdyke.h and spamdyke.c.
Added FILTER_FLAG_RETAIN and modified middleman() to buffer any data as long
as it is given.
Added FILTER_FLAG_CHILD_RESPONSE_INTERCEPT and modified middleman() to discard
any input from qmail when it is given.
Added FILTER_FLAG_DATA_CAPTURE and modified middleman() to capture qmail's
response to the end of the message data when it is given.
Fixed output_writeln() to send the data in bursts if more than one line is
given and no CRs need to be inserted. Previously, all data was sent
line-by-line, even though middleman() was trying to send bursts of data when
possible.
Changed middleman() to buffer the names of the accepted recipients until after
the message data is sent, then check qmail's response to the message body
and print ALLOWED/DENIED for each recipient accordingly, along with the text
of qmail's response.
Added the options header-blacklist-entry and header-blacklist-file to block
messages based on the contents of their headers.
Added the option rejection-text-header-blacklist to control the message from
the header blacklist filter.
Added a flag to smtpdummy to force it to reject all message content with an
error.
Added a more complete usage message to smtpdummy.
Fixed a number of very serious errors in the usage of snprintf()/vsnprintf().
The return value was being used as the length of the string printed into
the buffer, but the return value really indicates the length of the string
that *could* be printed if the buffer were of infinite size. Because the
returned value could be larger than the buffer's size, this meant remotely
exploitable buffer overflows were possible, depending on spamdyke's
configuration.
Added options to smtpdummy to make it appear to process authentication (and
unconditionally succeed or fail).
Changed the ALLOWED log message to show the text given by qmail when the
message is accepted.
This version extends the log messages to show why a blacklist is
matched. It also fixes a few minor bugs.
Added a filter to sendrecv so input containing "\r\n" will be
translated into CRLF without being interpreted as a line
terminator (so multiple commands can be sent in a single "packet")
and input containing "\0" will be translated into NULL bytes
so NULL characters don't have to be embedded in the test scripts.
Added support for the RSET command to smtpdummy.
Added a "priority" field to the input file for dnsdummy to force
some responses to be sent after others, no matter what order
they were received.
Fixed nihdns_mx() to query names for A records using the query
types configured for MX queries, not A queries. Thanks to Eric
Shubert for reporting this one.
Changed smtp_filter() and middleman() to discard any buffered
input after TLS is started. This prevents the injection of
commands into a secure session by sending extra input in the
same packet as the "STARTTLS" command. Not really a security
problem but good practice anyway. Thanks to Eric Shubert for
reporting this one.
Fixed a bug in examine_entry() that was cutting off 1-3 characters
from the end of target_entry every time it was called.
Changed check_ip_in_rdns_keyword() to return the line number of
the matching file as its return value and the name of the
matchine file in a reference variable.
Added reject_reason and strlen_reject_reason to struct rejection_data
to allow the triggered filter to return some text to indicate
why it triggered.
Changed set_rejection() to accept new parameters to set reason
text within the rejection structure if available.
Changed set_rejection() to accept a new parameter to append to
the rejection text if available.
Added reset_rejection() to change either the rejection text or
the reason text within an existing rejection_data structure
without erasing previously-set values.
Changed nihdns_rbl(), check_dnsrbl() and check_rhsbl() not to
accept a format string or build part of the rejection message.
That job belongs to the caller(s).
Changed filter_rdns_blacklist(), filter_rdns_blacklist_file(),
filter_rdns_blacklist_dir(), filter_ip_blacklist(),
filter_ip_in_rdns_blacklist(), filter_dns_rbl(), filter_dns_rhsbl(),
filter_sender_blacklist(), filter_sender_rhsbl() and
filter_recipient_blacklist() to save the reason for their
rejection in the reject_reason variable in rejection_data.
Changed the log messages showing ALLOWED/DENIED to always output
the "reason:" field and fill it with the text returned by the
triggered filter so the sysadmin can figure out what happened
or "(empty)" if no text was saved. Thanks to Eric Shubert for
suggesting this one.
Changed the way DNS timeout values are read from the configuration
file, the command line, /etc/resolv.conf and the environment
so that values given in the config file or on the command line
are not overridden by values in /etc/resolv.conf or the
environment. Thanks to Teodor Milkov for reporting this one.
Changed the reject-empty-rdns filter, the IP-related black/whitelist
filters and the IP-related RBL filters to skip their tests if
the incoming IP address is 0.0.0.0. This is for connections
from IPv6 hosts -- those filters can be skipped until full IPv6
support can be added. Thanks to Daniel Anliker for suggesting
this.
Changed the way the flag FILTER_DECISION_TRANSIENT_DO_NOT_FILTER
is handled by smtp_filter() and middleman() so a transient
non-rejection (e.g a recipient whitelist) isn't held over to
later recipients. The interaction between the recipient whitelist
and the graylist filter was fixed in version 4.0.0 but an issue
still remained between recipient whitelists and other non-transient
rejections like the missing rDNS filter. Thanks to bischowski
for reporting this one.
Changed smtpdummy to use memchr() instead of strchr() so testing
input with NULL bytes will work correctly.
Changed read_file() to return the number of usable lines read, instead of the
total number of lines (including comments and whitespace).
Fixed a huge thinko in many calls to read_file() -- when the function returns
0, the returned value is NULL. This was causing spamdyke to crash when no
content was read from files by "dns-blacklist-file", "dns-whitelist-file",
"rhs-blacklist-file", "rhs-whitelist-file" and "hostname-file". Thanks
to David Stiller for reporting this one and providing a lot of help in
tracking it down.
Added the option "tls-cipher-list" for specifying the list of ciphers to use
in SSL/TLS connections. This won't be an option many people will ever use,
but in specific setups it is required. Thanks to Chris Boulton for
suggesting this one and producing a patch to implement it.
Added a new value to "tls-level": "smtp-no-passthrough" to allow spamdyke to
offer TLS but prevent it from passing TLS through to qmail if the SSL
library cannot be initialized for some reason.
Fixed a bug in smtp_filter that allowed open relaying when spamdyke was
configured with "local-domains-entry" instead of "local-domains-file".
Moved code from do_spamdyke() that set stdin and stdout sockets to
non-blocking into tls_read() and tls_write() instead. Setting the sockets
to non-blocking through the entire run was causing some strange behavior
where logging would stop after a series of large inputs.
Refactored the address parser (yet again) to fix a bug that wasn't handling
routing addresses properly. Thanks to Chris Boulton for reporting this one.
Fixed process_config_file() to not reset a "multiple" value to default if it
was deliberately cleared during configuration.
Fixed prepare_settings() to initialize all default values before processing
the command line or configuration files so a "multiple" value can be cleared
during configuration.
Fixed configure.ac to use a gcc #pragma command to treat format warnings as
errors instead of relying on AC_LANG_WERROR (which doesn't always work).
Added the options "dns-query-type-a", "dns-query-type-mx",
"dns-query-type-ptr" and "dns-query-type-rbl" to limit the types of DNS
queries that can be sent for different purposes. Thanks to Teodor Milkov
for suggesting this one.
Fixed a bug that caused a timeout whenever a post-RCPT filter is triggered
on a non-local address. spamdyke is supposed to close the connection to
qmail and wait for its exit, but instead was just waiting for its exit,
leading to unnecessary timeouts. Thanks to Ulrich C. Manns for reporting
this one.
Fixed a typo in policy.php.example. Thanks to Richard Lamse for reporting
this one.
Fixed compiler warnings on Fedora 11. Thanks to Ertan Orhan for reporting
this one.
Fixed a bug in sendrecv where an uninitialized variable was causing erroneous
stalls and timeouts in CentOS 5.5.
Changed the option "hostname-file" to read /var/qmail/control/me by default.
Added the option "dns-resolv-conf" to read the nameserver from a file other
than /etc/resolv.conf if necessary. Multiple files can be read, if needed.
Changed all uses of strncpy() to memcpy() because strncpy() will fill the
remainder of the destination buffer with zeroes if the source string is
too short. This is not needed because all strings are being explicitly
terminated after copies anyway.
Added two new parameters to search_file() to allow the matching line data to
be returned to the caller.
Changed process_access() to save the contents of the RELAYCLIENT environment
variable, if set.
Added the timefilter program to the utils folder.
Reversed a small change to spamdyke_log() made 4.0.8 that will prevent buffer
overflows in obscure situations.
Changed is_ip_in_name() to look for more patterns of IP addresses in rDNS
names: 044.033.022.011, 44.033.022.011, 44.33.022.011 and 44.33.22.011.
Thanks to Eduard Svarc for suggesting this one.
Changed the syslog output to include an "encryption:" tag at the end that
shows the current status of TLS/SSL encryption. Thanks to Eric Shubert for
suggesting this one.
Added a "-R" option to smtpdummy so it will reject all recipients.
Completely rewrote find_address() to completely conform to RFC 2822 when
parsing addresses, including quoting, comments, folded whitespace and
all the rest.
Added the option "reject-identical-sender-recipient" to block any messages
where the sender and recipient are the same. Thanks to almost everyone
on the mailing list for suggesting this one.
Changed nihdns_mx() to tolerate MX records that contain IP addresses (illegal)
instead of names.
Fixed Makefile.in to use the CPPFLAGS variable from the "configure" script, if
the user provided it in an environment variable. Thanks to Iavor Stoev for
reporting this one.
Fixed the "configure" script to correctly include header files on FreeBSD 7.0.
Thanks to Andrew Khon for reporting this one.
Added a "-S" flag to sendrecv to prevent it from starting a TLS session when
it sees "STARTTLS".
Improved sendrecv's usage display to document what each option does.
Changed do_spamdyke() to set the stdin and stdout file descriptors to
nonblocking before calling middleman(). This works around a bug in the SSL
library that will block forever waiting for input, even after SSL_pending()
and/or select() has already indicated the socket is ready. Thanks to
Teodor Milkov for identifying this problem more than a year ago and trog for
producing a patch to fix it!
Fixed process_config_file() to reject configuration file lines with
bad/missing characters.
Fixed process_config_file() to print an "unknown option" error message instead
of an "illegal option" message when an unknown option is found in a
configuration file.
Added option "rejection-text-identical-sender-recipient" to set the rejection
message for the identical sender/recipient filter.
Created dnsdummy to simulate a nameserver but exit after a short while for
testing spamdyke's DNS routines.
Converted all DNS-related tests to use dnsdummy and removed all references to
spamdyke.org and silence.org. This will also allow the removal of the
(hundreds of) bogus entries from the spamdyke.org zone file.
Removed the use of getprotobyname() from dns.c and used the defined protocol
values in netinet/in.h.
Changed nihdns_query() to retry DNS queries via TCP if the response received
via UDP has the "truncation" flag set (indicating the answers are too large
for a UDP packet). Thanks to Roland Moelle for suggesting this one.
Added option "dns-tcp" to control if spamdyke will retry DNS queries via TCP.
Added option "dns-spoof" to control if spamdyke will attempt to detect DNS
spoofing and, if so, what it should do about it.
Fixed smtp_filter() to offer and accept SMTP AUTH (when appropriate) even if
the connection is already whitelisted. Thanks to Ratko Rudic for
reporting this one.
This version adds a workaround for a bug in Plesk 9 that provides
the text "localhost" instead of the IP address for some connections.
Thanks to Medovarszky Zoltan and Christian Aust for reporting this
one.
This version fixes a bug in the address parser that was preventing
some sender/recipient whitelist/blacklist entries from matching.
Thanks to John Devenport for reporting this one. This version also
fixes a bug in the "config-test" feature that prevented spamdyke
from finding its own binary when the file is not in the current
directory. Thanks to John Hallam for reporting this one.
Changed spamdyke_log() to send all messages to stderr (when appropriate) using
a single call to vfprintf() by adding newline characters and PID prefixes to
the format before outputting anything. This is necessary to work around a
problem with the design of DJB's multilog program, which uses a single pipe
to accept input from all processes and thus cannot keep log messages
separate. This means partial output from some spamdyke processes could
overlap output from other spamdyke processes when the load rises (a race
condition). Thanks to Philip Nix Guru for reporting this one.
VERSION 4.0.7: 10/17/2008
Changed Makefile.in to compile configuration.c in two steps: first use gcc
to produce the preprocessed source, then use gcc to compile it. For some
reason, gcc crashes on FreeBSD 6.0 when the file is compiled in one step.
Thanks to K. Shantanu for reporting this one and Felix Buenemann for
suggesting the fix.
VERSION 4.0.6: 10/16/2008
Fixed a problem in examine_ip_in_rdns_keyword_entry() that was not correctly
terminating the end of the keyword buffer, causing strstr() to search too
far, leading to false negatives (and potentially segmentation faults).
Thanks to Erald Troja for reporting this one.
Fixed another problem in middleman() that was not correctly replacing _all_
of qmail's AUTH advertisements when the "smtp-auth-level" option is
"always" or "always-encrypted". Thanks to Youri Kravatsky for reporting
this one (again).
Fixed the fix to a bug in nihdns_query() that was setting
return_target_name_index to 0 in all cases. This was causing log messages
to print the first RBL/RHSBL name instead of the one that actually matched.
Thanks to Arthur Girardi for reporting this one (again).
Reverted a change from 4.0.5 -- removing the usable_buf_input flag from
middleman() meant could only tell if there was input in the buffer, not if
any of it was actually usable. If the remote server delays sending its
data for any reason, middleman() will loop rapidly to continually check if
its buffered data can be sent to qmail. Removing the flag meant spamdyke
was consuming 100% CPU while receiving messages with large attachments.
Thanks to Paulo Henrique Fonseca for reporting this one.
Added the "cputime" program to the "tests" folder to measure the CPU time
used by a process. Neither the shell "time" command nor the POSIX "time"
command seem to do that.
Changed sendrecv to always wait() for its child processes so CPU accounting
will be performed correctly.
Fixed check_rhsbl() to correctly return the name of the matching RHSBL instead
of an index that could be beyond the end of the array.
Changed the values of LOG_USE_CONFIG_TEST, LOG_USE_STDERR and LOG_USE_SYSLOG
to make none of them equal to 0. Because the "log-target" option is a
CONFIG_TYPE_NAME_MULTIPLE option, it is set to 0 until the command line and
all configuration files are parsed. When LOG_USE_CONFIG_TEST is 0, the
progress messages from process_config_file() are sent to stderr until the
configuration file is completely loaded. For Plesk users, xinetd sends
stderr to the network connection, so the remote server gets the output.
Thanks to Arthur Girdari for reporting this one and helping track it down.
- If the idle timeout is not configured, it is now set to 20 minutes
after qmail exits to prevent never-ending spamdyke processing.
Thanks to Matthew Kettlewell for reporting this one.
- Fixed the AUTH advertisements to display correctly when
"smtp-auth-level" is "always" or "always-encrypted". Thanks
to Youri Kravatsky for reporting this one.
- Fixed a sequencing error that would cause qmail to exit prematurely,
even if valid recipients could still possibly be given. Thanks
to David Stiller for reporting this one.
- Fixed the handling of unencoded null characters in messages
(technically not legal) so spamdyke does become confused and
timeout. Thanks to Arthur Girardi for reporting this one.
- Fixed an issue in the DNS query code that was setting array indexes
beyond the end of the array, resulting in garbage log messages
and segmentation faults. Thanks to Arthur Girardi for reporting
this one.
- Fixed verbose logging in the RHSBL filter to print the correct
log message. Thanks to Arthur Girardi for reporting this one.
- Rewrote the address parser to correctly handle strange/invalid
email addresses. Thanks to Erald Troja for reporting this one.
- Fixed a serious error in the code that loads array values from
files that was returning pointers to unallocated memory, causing
segmentation faults. Many, many thanks to David Stiller for
reporting this one and providing tons of help to nail it down.
- Fixed a serious error that was attempting to move data by
dereferencing the NULL address when the remote server disconnected
unexpectedly, causing segmentation faults. Many, many thanks
to David Stiller for reporting this one and providing tons of
help to nail it down.
Moved the code for loading configuration files into prepare_settings() from
do_spamdyke(). When the default value for the "log-target" option was
being set before the configuration files were read, the syslog option
could be incorrectly set, even if stderr was specified in a file.
Thanks to Eric Shubert for reporting this one.
Changed the configure script to detect environments where printf()/scanf()
use "%ld" for 64-bit integers instead of "%lld" (CentOS 64-bit). This
wouldn't be necessary if the gcc authors could grasp the idea that
"long int" and "long long int" may be interchangable and not emit warnings.
Thanks to kjl for reporting this one.
This version fixes two bugs. The first is an integer argument
parsing bug on some systems (FreeBSD). Thanks to Shane Bywater for
reporting this one. The second is a bug parsing invalid nameserver
entries in /etc/resolv.conf that prevented spamdyke from defaulting
to 127.0.0.1. Thanks to slamp slamp for reporting this one.
Fixed a bug in filter_graylist() that was creating infinitely deep "_none"
directories. The special-case conversion code added in 4.0.1 was not
checking to see if "_none" was a file or a directory and performing the
conversion every time. Thanks to Bob Alanis for reporting this one.
- The automatic conversion of a graylist directory structure could
generate errors for empty sender addresses (commonly used for
bounce messages). Thanks to David Stiller for reporting this one.
- Connections encrypted with TLS (not decrypted by spamdyke) weren't
always being rejected, even if there was no chance they should
be accepted. Thanks to Sergio Minini for reporting this one.
- A double-free() problem could result in crashes if the
"rejection-text-graylist" option was used within a configuration
directory.
- Compiling on Solaris was generating a warning.
This version fixes a bug with the recipient filters that could allow
a clever sender to use a spamdyke-protected server as an open relay.
The sequence of commands are not legal SMTP, so the sender would
have to know the server was running a vulnerable version of spamdyke
to exploit this bug. Thanks to Mirko Buffoni for reporting this
one.
This version also fixes two problems with the idle timeout filter.
The first could cause the connection to be rejected because qmail
is slow to respond (which isn't fair). The second was a tricky
issue where large messages from fast remote servers could be
improperly rejected because the idle timer wasn't being reset.
Thanks to Eric Shubert for reporting and helping me fix this one.
This version also fixes two compiling problems. The first was a
problem in the "configure" script on older Gentoo installations
running gcc 3.4.6 that was treating a preprocessor warning as an
error. Thanks to Thorsten Puzich for reporting and helping me fix
this one. The second was a problem with CentOS 3.8, which doesn't
install the OpenSSL headers in the system include folder. Thanks
to Bruce Schreiber for reporting this one.
This version fixes a bug in the white/blacklist file processor that
was incorrectly matching domains when wildcards were used. Thanks
to Tom for reporting this one.
of some log entries have changed since 2.6.3; see UPGRADING.txt.
Also, pkgsrc no longer installs the random extra utilities that are
explicitly marked as unnecessary for spamdyke operation. From the
changelog:
VERSION 3.1.6 -- 2/11/2008
Fixed a serious bug in middleman() -- when the remote server sent its message
data and QUIT command in a burst and disconnected before spamdyke read() all
of the data, the last data returned from read() was printed twice. This
could cause message corruption, especially in the case of attachments.
Fixed a serious bug in middleman() -- when the remote server sent its data
in bursts of 4096 bytes AND there were two lines of text in the data
AND the 4096th character was not a newline AND there was a delay between the
data bursts, memmove()ing the buffered data was causing corruption because
the moved data was not being properly re-terminated. While processing the
remaining buffered data (and waiting for another burst from the remote
server), strchr() would seek past the end of the data to an old newline
character and middleman() would erroneously conclude the next line of data
was complete, ready for processing. Many thanks to Andreas Galatis and
Dragomir Denev for reporting and helping me reproduce this one.
Added a -W flag to sendrecv to introduce a delay between message data bursts.
Added a -o flag to smtpdummy to save the message data to a file.
VERSION 3.1.5 -- 1/22/2008
Fixed sendrecv to correctly process corrupted TLS negotiations instead of
covering up bugs in spamdyke.
Fixed spamdyke to not add garbage output at the beginning of TLS passthrough
negotiations. This was causing SSL handshakes to fail. Thanks to Ronnie
Tartar for reporting this one.
VERSION 3.1.4 -- 1/21/2008
Fixed all of the Makefiles to remove a symbols directory Leopard's gcc seems
to create when compiling in debug mode.
Fixed middleman() to log the timeout message only once.
Fixed middleman() to not expect input from the child process when the child
process' input is being ignored or after the child process has exited.
Fixed middleman() to correctly handle a rare situation -- when the child
process was too slow responding that spamdyke's idle timeout was passed
AND spamdyke was processing TLS data AND there was still data in the SSL
buffer, spamdyke would loop infinitely, consuming 100% CPU. This was a
very tricky bug to find and fix. Thanks to Pablo Gonzalez and Paolo for
reporting this one and helping me debug it.
Fixed middleman() to send message data to the child process line-by-line,
even when the buffer is full.
Added a new test program: smtpdummy. This one simulates an SMTP server and
can add delays after specific commands.
Changed sendrecv to use a 64K buffer for input and output data.
Changed sendrecv to kill the its child process after its timeout expires.
Changed sendrecv to optionally continue sending data in bursts after the end
for the message data. Some mail servers do this.
Changed sendrecv to deliberately send corrupt data while TLS is active.
Changed test regression_009 to build its message payload at runtime instead
of including a 0.75M file. This file was unnecesarily increasing the size
of the spamdyke tarball.
Fixed compiling on Solaris. Again. Thanks to Davide Bozzelli for reporting
this. Again. Sigh.
VERSION 3.1.3 -- 1/3/2008
Fixed the format string LOG_INFO_DNS_TXT to assign the parameters correctly
and prevent bus errors when the DNS response text is long. Thanks to
Stephan Rosenke for reporting this one.
VERSION 3.1.2 -- 12/11/2007
Fixed smtp_filter() to set a flag after some SMTP commands to force
middleman() to wait for input from the child process before proceeding.
Some (nonspammer) mail servers send their data in bursts without waiting for
responses. This was causing spamdyke to skip logging (but not filtering)
if the DATA command was sent in a burst with RCPT TO. Thanks to Sebastien
Guilbaud and Bucky Carr for reporting this one.
Added a "-b" flag to sendrecv to simulate servers that send their message data
(but not their SMTP commands) in bursts.
VERSION 3.1.1 -- 11/12/2007
Added excessive logging to search_domain_directory() to log the directory
search pattern.
Changed all calls to spamdyke_log() to use the macros SPAMDYKE_LOG_NONE(),
SPAMDYKE_LOG_ERROR(), SPAMDYKE_LOG_INFO(), SPAMDYKE_LOG_DEBUG() and
SPAMDYKE_LOG_EXCESSIVE() instead. The macro tests the current log level
without forcing a function call and also paves the way toward eliminating
some logging code at compile-time.
Fixed process_access() to correctly search for the RELAYCLIENT variable in
spamdyke's environment. Thanks to Steve Cole for reporting this one.
VERSION 3.1.0 -- 11/5/2007
Changed the "graylist-dir" and "no-graylist-dir" options to take multiple
directories for servers that are hosting so many domains that they can't
create enough domain folders in one place (wow).
Added minimum and maximum values to all integer options and changed
set_config_value() to generate error messages when values are out of range.
Change usage() to print minimum and maximum integer values.
Alphabetized the option list by long option name and changed
process_config_file() to use a binary search algorithm when identifying
directives, a theoretical improvement from O(n/2) to O(log n).
Changed prepare_settings() to create an array of options indexed by the short
option code. This introduces some constant-time work (O(1)) and greater
memory usage.
Changed process_command_line() to use the indexed array of options,
theoretically reducing command line parsing work from O(n/2) to O(1).
This is a win if the command line has many parameters or if it has
parameters that are near the end of the unindexed option array.
Testing confirms a small performance gain.
Added command line options "config-test-smtpauth-username" and
"config-test-smtpauth-password".
Changed config_test_smtpauth() to run the authentication command(s) if a
username and password are provided. This incorporates the functionality of
checkpassword into spamdyke.
Added the command line option "config-test-user" to change user and group IDs
before running the configuration tests. This makes it easier to simulate
running as the mail server.
Changed process_config_file() and process_command_line() to print errors and
stop when they encounter an option that is not legal in that location. At
the moment, "help", "version", "config-test",
"config-test-smtpauth-username", "config-test-smtpauth-password" and
"config-test-user" are not valid in files; all options are valid on the
command line.
Changed config_test_dir_read() and config_test_graylist() to never examine the
"." or ".." folders, even if readdir() and/or stat() report they are not
folders. Thanks to Paulo Henrique for reporting this one.
Changed set_config_value() to remove trailing slashes from directory paths.
Added test_spamdyke_binary() to check if the spamdyke binary is setuid root
(it should not be).
Renamed test_settings() to config_test().
Moved all of the configuration test functions to config_test.[ch] -- they were
cluttering up configuration.c.
Made a few small updates to the help message text.
Added additional vchkpw exit codes to exec_checkpassword() to explain why
vchkpw exited, since it doesn't follow DJB's published checkpassword API.
Moved md5.[ch] from the "utils" folder to the "spamdyke" folder and updated
Makefile to compile them into spamdyke.
Removed passwordcheck from the "utils" folder since spamdyke now contains its
functionality.
Added a README file to the "utils" folder to answer the biggest FAQ about
those utilities.
Fixed exec_command() to connect the output pipe to the child process's stdin
instead of file descriptor 3. The bug was due to copying
exec_checkpassword() and forgetting to change the value.
Renamed exec_checkpassword() to exec_checkpassword_argv() and changed its
arguments to expect a filename and an argument array.
Added exec_checkpassword() to parse a command string into an argument array
and call exec_checkpassword_argv().
Renamed exec_command() to exec_command_argv() and changed its
arguments to expect a filename and an argument array.
Added exec_command() to parse a command string into an argument array
and call exec_command_argv().
Fixed numerous bugs in exec_command_argv() that were preventing it from
actually gathering any input from the child process.
Changed exec_command_argv() and exec_checkpassword_argv() to always log their
child process errors to syslog, regardless of the user's preferences.
Otherwise, the errors will be lost.
Added the function find_path() to search the PATH for the given command
without executing it.
Changed exec_command_argv() and exec_checkpassword_argv() to use find_path()
to locate the executable before fork()ing to catch typos. The child
processes then use execve() to execute the command instead of exec_path().
Otherwise, the parent has a hard time determining that the child process
quit because the command path was invalid.
Changed exec_command_argv() and exec_checkpassword_argv() not to wait
indefinitely for the child to exit after the timeout expires.
Changed dns_txt(), dns_ptr_lookup() and dns_mx() to limit the total number of
queries they will recursively perform. This is to prevent a DoS situation
where some domain has an unreasonable number of chained (non-circular) CNAME
records. The limit is (arbitrarily) set at 16.
Added the function config_test_child_capabilities() to test the qmail binary
for SMTP AUTH and TLS patches. Depending on what is found, recommendations
for spamdyke flags are made.
Changed check_rdns_keywords() to allow top-level domains (like .com) to be
used as keywords. This allows a way to reject connections from remote
servers with rDNS names that contain the IP address and a two-letter country
code. Unlike check_country_code(), specific country codes can now be
chosen.
Fixed do_spamdyke() not to wait indefinitely for all child processes to exit.
This behavior was causing problems with DJB's recordio because recordio
fork()s and uses its parent process to exec() spamdyke. This is very
unusual. Changing wait(NULL) to waitpid() fixes the problem. Thanks to
Bob Hutchinson for reporting this one.
Added dns_initialize() and dns_get() to perform DNS queries by sending UDP
packets instead of using the resolver library to do it. The resolver
functions are just too slow and they try to do too much unnecessary work.
dns_get() performs multiple requests for records (one for each kind of
desired record) and, if no responses are received, sends requests to the
secondary nameservers as well. Timeouts and retransmission times can now
be controlled. This has resulted in a significant speedup in DNS
resolutions; testing shows as much as a 10x performance increase in some
situations.
Changed dns_txt(), dns_ptr_lookup() and dns_mx() to search all of the answers
for the desired answer type before recursively querying CNAME answers. Some
nameservers always put the CNAME answers first, even if other answer types
are also given. This should allow spamdyke to find answers faster when
domain admins have used a lot of CNAMEs.
Added dns_a() to perform A record queries and changed all uses of
gethostbyname() to use dns_a() instead.
Changed dnsa, dnsmx, dnsns, dnsptr, dnssoa and dnstxt in the "utils" folder to
only perform their specific queries, not ask for CNAME records as well.
Changed dnsa, dnsmx, dnsns, dnsptr, dnssoa and dnstxt in the "utils" folder to
send their own UDP packets instead of using the resolver library.
Added dnscname to the "utils" folder to perform CNAME queries.
Added dnsany to the "utils" folder to perform ANY queries and perform
recursive CNAME lookups.
Added "log-target" option to allow logging to stderr instead of syslog. Some
people apparently like using the qmail-style "multilog" instead of syslog.
I can't understand why but I'm here to serve. Thanks to John Hallam for
suggesting this one.
Changed all of the error messages about unexpected file types to specify what
file type was found -- "non-regular file" was too vague to be useful.
Changed the header in the files created by full logging to include the
spamdyke version.
Changed tls_end_inner() to use SSL_get_shutdown() to see if a shutdown signal
has already been received. If SSL_shutdown() is used on a closed file
descriptor, spamdyke will crash with SIGPIPE.
Changed all instances of read(), write(), SSL_read() and SSL_write() to read
or write as many bytes as possible in each call. This should provide a
significant performance increase. The single-byte read()s and write()s
were only used because I had badly misunderstood the relationship between
select() and read()/write() -- blocking only occurs when select() indicates
a file descriptor is not ready. If it is ready, read() and write() will
handle as many bytes as they can without blocking. Thanks to Trog for
setting me straight on this one.
Rewrote most of sendrecv in the "tests" folder to use a multi-byte read().
Also took the opportunity to make sendrecv much faster and more polite, so
it doesn't consume 100% CPU while waiting for qmail output.
Fixed compiling errors on 64 bit Linux systems (Debian Etch x86_64 and Gentoo
AMD64). Thanks to Juha-Pekka Jarvenpaa and FireBall for reporting this.
Added config_test_file_type() to use stat() to find a file's type if readdir()
either doesn't report it (Solaris) or reports "unknown" for all files (XFS).
Thanks to Paulo Henrique for reporting this one.
Fixed compiling errors on Solaris. Thanks to Limperis Antonis for reporting
this.
Changed the logging severity of the "unable to write X bytes to file
descriptor" to debug instead of error. 99% of the time, the error occurs
because the remote client disconnected unexpectedly and there's nothing
the administrator can do about it anyway.
Changed do_spamdyke() to ignore SIGPIPE signals.
Changed do_spamdyke(), exec_command_argv() and exec_command_checkpassword()
to change the SIGPIPE signal handler back to default for child processes
after fork()ing but before exec()ing.
Added a new logging level: excessive (4). It's to be used for printing very
detailed debugging statements.
Changed process_access() to permit access when no matching lines are found in
the access file. Although DJB's tcprules documentation doesn't explicitly
say so, no matching lines should allow access. Thanks to Steve Cole for
reporting this one.
VERSION 3.0.1 -- 9/12/2007
Fixed "configure" to remove the "_beta1" tag from the version number. That
should never have been published.
Changed usage() to show that optional values to long commands must be
separated by an equals sign. getopt_long() is really becoming a hassle.
Thanks to Richard Kreider for reporting this one.
Fixed find_address() to accept addresses that aren't correctly delimited with
<> characters and/or have multiple (illegal) spaces after the colon. Thanks
to Davide Bozzelli for reporting this one.
Fixed prepare_settings() to set the idle timeout seconds to the correct
variable instead of setting the connection timeout variable. Thanks to
Carlo Blohm for reporting this one.
Fixed smtp_filter() to print the rejection message to HELO and EHLO, even if
those commands appear in an improper place in the protocol.
Fixed smtp_filter() to print the rejection message with an error code in
response to STARTTLS if the command is given in an improper place in the
protocol.
Added some regression tests to find these bugs in the future.
Fixed the usage statement in sendrecv to show the -w flag.
VERSION 3.0.0 -- 9/11/2007
Added command line options never-graylist-rdns-dir, always-graylist-rdns-dir
and rdns-whitelist-dir to search domain directory structures just like
rdns-blacklist-dir.
Added the command line option rdns-blacklist-file to search a file just like
rdns-whitelist-file.
Moved the command line option labels into configuration.c so they can be
shared with the config file parser.
Changed process_command_line() to build the list of short options from the
list of long options instead of hardcoding them. Less maintenance this way.
Modified check_rdns_keywords(), search_file() and search_tcprules_file() to
correctly track line numbers and return the matching line number instead of
just 1.
Changed logging to allow the amount of information to be turned up or down.
This should make spamdyke less chatty in the syslog for small errors.
Modified smtp_filter() and run_tests() to report the matching filename and
line number from check_rdns_keywords(), search_file() and
search_tcprules_file() in syslog if the logging level is high enough.
Fixed find_address() to locate the real email address and ignore BATV tags,
relay paths and bang paths. Thanks to Walter Russo for reporting this one
(again).
Changed middleman() to obey minimums and maximums for the amount of time to
select() for traffic. If spamdyke waits too long, the qmail process might
not get wait()ed for a while, leaving a lot of defunct/zombie processes
around. On a busy server, this could be a problem. Thanks to Jason M for
reporting this one.
Added process_config_file() to process configuration files instead of
requiring all configuration to be done on the command line. At the moment,
the file just uses the same (long option) directives as the command line.
Added test_settings() to run tests on every configuration option and
(hopefully) identify misconfigurations before someone makes them on a live
server.
Added the command line option "config-test" to run test_settings().
Renamed log_writeln() and log_write_rejection() to output_writeln() and
output_write_rejection(), respectively, to make it clearer what they're
doing.
Changed smtp_filter() to allow multiple authentication attempts. Some
clients retry authentication several times, presumably to deal with servers
that can't use the authentication method they prefer.
Changed middleman() to collect (and send) whole lines of input instead of
single characters. Single character write()s were causing problems with
Nagios and Windows clients.
Changed output_write_rejection() to create a single output line and send it
to output_writeln() all at once instead of sending a piece at a time. This
keeps packets together for stupid Windows clients that just can't handle
reassembling TCP packets correctly.
Changed main() to always run spamdyke (as opposed to starting qmail without
spamdyke listening) even if a whitelist is matched. This way, spamdyke
can report all traffic to syslog, not just traffic that _may_ be filtered.
Changed smtp_filter() and middleman() to catch the return codes from qmail
when the remote client gives the recipient address. Now, if spamdyke
doesn't block the recipient command but qmail does (e.g. for relaying),
spamdyke will log the correct message.
Incorporated GNU autoconf to create a "configure" script for spamdyke and the
"utils" folder. The days of "make no_tls" and "make bsd" are thankfully
over.
Renamed all of the test folders to group them by function so it's easier to
see what tests exist. Sequential numbers just weren't working.
Changed dns_mx() to lookup the MX record before returning success. This means
the sender MX filter now requires a mail exchanger record _and_ at least one
mail exchanger must have an IP address. Before, the MX record was enough,
even if there was no corresponding A record.
Changed usage() to read the options and help text from get_spamdyke_options()
in configuration.c so the help message won't ever be out of sync with the
available options again.
Added the command line option "tls-privatekey-password-file" to allow the SSL
private key password to be read from a file instead of the command line.
This way, the password isn't visible to everyone who can view a process
list.
Changed search_file(), search_tcprules_file() and check_rdns_keywords() so
they no longer build their fscanf() patterns into a stack variable but
instead use a literal search pattern assembled at compile time with
STRINGIFY().
Added the command line options "hostname-file" and "hostname-command" to
support reading the local hostname from a file or from a command (e.g.
"hostname -f") instead of forcing it to be specified on the command line.
Changed middleman() and smtp_filter() to always monitor and trust
authentication carried out by qmail, even if "smtp-auth-command" was not
given. This means spamdyke will always disable its filters for
authenticated users even if it can't check the authentication itself.
I'm not sure why I didn't design spamdyke this way in the first place.
Added command line options recipient-whitelist-file and sender-whitelist-file
so specific sender and recipient addresses can bypass the filters. Sender
addresses are very easy to fake and recipient addresses are, of course,
known to spammers, so both of these options are ill-advised. I've only
added them due to popular demand.
Added command line option check-rhsbl to check righthand-side blacklists.
Both the server's rDNS domain name and the sender's email domain name are
checked.
Added command line options check-dns-whitelist and check-rhs-whitelist to
allow DNS RBLs and RHSBLs to act as whitelists instead of blacklists.
Anyone using DNS-based blacklists _and_ whitelists had better have some
seriously fast DNS servers.
Changed dns_txt(), dns_mx() and dns_ptr_lookup() to pass a stack of previous
queries whenever they recursively lookup CNAME records, to prevent a cylical
CNAME structure from leading to infinite recursion.
NOT BACKWARDS COMPATIBLE: Changed the syslog entry format: renamed "origin" to
"origin_ip", added "origin_rdns:" before the rDNS name, added "auth:"
before the authenticated username and added "reason:" before the rejection
reason when a timeout occurs.
Changed process_command_line() to assume the remote IP address is 0.0.0.0 if
the environment variable TCPREMOTEIP is not set.
Added a ton more test scripts for all of the new options and for testing
config files.
Added dnsa, dnsns and dnssoa to the "utils" folder for performing DNS queries
of A, NS and SOA records, respectively. Wouldn't it be AMAZING if the
libc maintainers added standard functions to do these queries?!
NOT BACKWARDS COMPATIBLE: Changed the "flag" options to take optional
arguments instead of simply assuming "true" when the option was given.
Unfortunately, getopt_long() is too stupid to handle them properly, which
means clustered options (e.g. -rRc) can no longer be used. They must be
separated (e.g. -r -R -c). Also, arguments given with the short version
must not be separated by a space (e.g. -l3).
NOT BACKWARDS COMPATIBLE: Renamed the long command line option "use-syslog"
to "log-level".
Fixed middleman() to completely bypass all processing when TLS passthrough is
active. The additional processing was buffering TLS traffic until the data
contained a newline character (purely by coincidence). This buffering was
preventing the passthrough from functioning properly. Thanks to Dominik
Dausch for reporting this one.
For now, DragonFly and FreeBSD use the libc version, it is not reentrant,
but thread-safe. NetBSD 3.0+ and Darwin 8.0+ use libresolv from base
(the BIND9 resolver), all other fall back to net/bind9. Feel free to add
your favorite platform if it has a thread-safe resolver in base.
Modify mail/libspf-alf, mail/milter-greylist, mail/spamdyke and
net/nocol accordingly. Testing on !DragonFly and feedback from tron@
Fixed a serious bug where spamdyke was closing the connection to qmail and
exiting as soon as the remote host exited. When the remote host sends its
SMTP data in one burst and closes the connection without waiting for the
response code from the DATA segment, qmail doesn't accept the message and
nothing gets delivered.
Added some code to log_writeln() to translate bare carriage returns into
carriage return/linefeed combinations. This allows poorly written remote
servers to send mail, most notably Microsoft web servers. Dogmatically
refusing to accept mail by refusing to be more flexible than RFC 822
will never change the world; let's be reasonable instead of bouncing
messages back to our friends who can't change their mail servers anyway.
Fixed smtp_filter() to accept parameters to AUTH LOGIN when the MUA sends the
authentication information with the command instead of waiting for the
prompts. Thanks to Carlo Blohm for reporting this one.
Fixed smtp_filter() to accept parameters to AUTH PLAIN when the MUA sends the
authentication information with the command instead of waiting for another
prompt.
Changed find_address() to strip BATV tags from addresses so whitelist/
blacklist matching can still take place. Reported by Walter Russo.
Added utils/passwordcheck to help troubleshoot SMTP AUTH problems.
Added more logging to exec_checkpassword() to aid troubleshooting.
* Changed calls to tolower() and isalnum() to eliminate warnings
from gcc 3.3.3 on NetBSD 3.1. Thanks to David Frese for reporting
this one.
* Fixed a very small typo in the new mask/flag system that was
preventing spamdyke from advertising SMTP AUTH on unpatched
qmail servers -- FILTER_FLAG_AUTH_ADD had the same value as
FILTER_FLAG_AUTH_NONE. Oops. Thanks to Renato Franzin for
reporting this one.
* Fixed an oversight in the use of gethostbyname() to perform DNS
lookups for A records. If the server is configured to search
a domain for matching names ("search" in /etc/resolv.conf) and
the domain has a wildcard DNS entry, the DNS RBL code was always
matching because an A record was always found. Adding a dot
to the end of the queried name prevents the domain searching
and returns correct results. Thanks to "Paolo", Alexander
Fordyce and Jens Mickerts for reporting and helping me troubleshoot
this one.
Added support for STARTTLS, similar to the way SMTP AUTH is implemented -- if
a server certificate is available, spamdyke takes care of the TLS. If not
but qmail supports TLS, spamdyke passes it through.
Changed the read() and write() calls to the network to use macros named
NETWORK_READ() and NETWORK_WRITE() that are replaced by TLS routines when
TLS support has been compiled in.
Changed the smtp_filter() return codes to use a mask/flag system because the
possible permutations of PASS/INTERCEPT/QUIT with ADD/REMOVE/CAPTURE AUTH
and ADD/REMOVE/CAPTURE TLS and CHILD QUIT/CONTINUE were getting too complex.
Fixed search_file() to match a file entry where the search text matches the
entry completely but the entry has wildcard markers at the start and/or end.
Added TLS support to tests/sendrecv so TLS can be tested from scripts.
Fixed numerous small bugs in tests/sendrecv that were causing inaccurate test
results (false positives and false negatives).
Updated all of the test scripts to make renumbering them easier.
Added a new test script to exercise a small whitelist wildcard bug I found.
Added 10 new test scripts to exercise the new TLS features.
Changed process_command_line() and usage() to print a brief usage message if
no parameters are given.
Changed process_command_line() and usage() to print a brief error message if
a bad parameter is given.
Changed process_command_line() and usage() to print the full usage message if
-h or --help is given.
Changed process_command_line() and usage() to print the version header if -v
or --version is given.
Renamed test_smtpauth_crammd5, test_smtpauth_login and test_smtpauth_plain to
smtpauth_crammd5, smtpauth_login and smtpauth_plain, respectively.
Moved smtpauth_crammd5, smtpauth_login and smtpauth_plain from the utils
folder to tests/smtpauth, since they're only used by the test scripts
anyway.
Added alternate command line options for people who spell "gray" with an "e".
They do the same thing.
Updated the documentation.
Moved portions of spamdyke's code from spamdyke.c into new .c and .h files to
make it a little easier to understand and maintain.
Added base64_encode() and base64_decode() to transfer data to/from base64
format.
Added md5() to produce an MD5 digest of a data block. Turns out this wasn't
necessary for spamdyke, only for test_smtpauth_crammd5. Oops.
Renamed the "make openbsd" command to "make bsd" since apparently all *BSD
distributions don't need -lresolv.
Renamed search_ip_file() to search_tcprules_file() and extended it to support
IP ranges, rDNS names and remote info like tcprules does (according to
http://cr.yp.to/ucspi-tcp/tcprules.html). This makes the IP black/
whitelist files much more flexible. This will be much handier in the next
version (AKA The Great Configuration Overhaul).
Modified middleman() and smtp_filter(), added exec_checkpassword() so spamdyke
can do SMTP AUTH, either by offering it itself or observing the qmail
traffic. LOGIN, PLAIN and CRAM-MD5 are supported.
Changed the STRLEN_ macros in spamdyke.h to use a single STRLEN() macro so the
preprocessor will count characters instead of doing it by hand. Much safer
this way.
Removed "-a"'s (max number of recipients per message) dependence on "-d"
(local domains file). With SMTP AUTH, the local access file and whitelists,
this shouldn't be necessary.
Added process_access() to process local access files (e.g. /etc/tcp.smtp) and
export environment variables based on the source of the incoming connection.
Added relay prevention based on the content of the local access file(s) and
the list(s) of local domains. Connections from remote sources that are
granted relay permission in the access file(s) are allowed to relay. Users
who authenticate with SMTP AUTH are allowed to relay. All others must send
to local addresses only.
Added a series of test scripts to exercise all of spamdyke's filters and
options. This should make it easier to regression test new versions.
Changed search_file() and search_tcprules_file() to compare domain names in a
case insensitive manner.
Changed canonicalize_path() to reduce all file paths to lowercase. This was
causing graylisting to be inconsistant. Reported by bcarr@purgatoire.org.
Added search_ip_file() to search files for IP addresses and allow wildcards,
network sizes (numbers of bits, e.g. 11.22.33.44/16) and netmasks (e.g.
11.22.33.0/255.255.255.0).
Added new options to allow graylisting exclusions by IP address and rDNS
name.
Added new options to activate graylisting for only certain IP addresses and
rDNS names.
Updated the documentation.
Added some explicit casting to printf("%.*s") arguments to make them ints
instead of longs. gcc 3.3 on OpenBSD was complaining.
Changed a datatype in log_write() from long to time_t. gcc 3.3 on OpenBSD
was complaining.
Changed all uses of sprintf() to snprintf(), even though they were already
safe from buffer overruns. gcc 3.3 on OpenBSD was complaining.
Added a new target to the Makefile in the spamdyke and utils folders named
"openbsd" that compiles without the "-lresolv" flag. gcc 3.3 on OpenBSD
includes the resolver library automatically and throws an error when it
is explicitly specified.
Added some additional #include directives in dnsmx.c, dnsptr.c and dnstxt.c
because they're not included by resolv.h on OpenBSD.
Gained a broader understanding of the resolver library and DNS packet
structure, then rewrote most of dns_txt() and dns_ptr_lookup() to (more)
correctly process DNS data.
Added dns_mx() to perform MX record lookups.
Changed process_command_line() to use getopt_long() and added long option
equivalents to the existing command line flags.
Added the option "reject-missing-sender-mx" to reject email from senders
whose domains aren't local and don't have MX records and/or A records.
AOL does this.
Updated the usage statement to show the new (long) command line options.
Updated the README.txt to show the new (long) command line options.
Moved domain2path and domainsplit into a new folder named "utils".
Created dnsmx, dnsptr and dnstxt in the utils folder by copying the dns_mx(),
dns_ptr() and dns_txt() functions from spamdyke. They are simple command
line utilities that no one will ever use except as examples of how to make
MX, PTR and TXT DNS queries using libc. As far as Google knows, there are
no such examples anywhere else on the internet.
Changed the DNS RBL code to check for A records in addition to TXT records.
Some RBLs are using A records, I don't know why.
Fixed the DNS RBL code not to check 127.0.0.1 for RBL entries.
spamdyke monitors incoming traffic, acting as a middleman between
qmail and the remote server. It catches the sender and recipient
addresses as they go by and logs them to syslog. If it sees something
it doesn't like (e.g. a blacklisted sender), it cuts the connection,
closes qmail and fakes the rest of the SMTP transaction with the
remote server. qmail thinks the remote server disconnected normally.
The remote server thinks qmail is rejecting the message. It's the
best of both worlds.
spamdyke can optionally reject the connection if the remote server's
reverse DNS entry does not exist, does not resolve, contains its
IP address and either contains a prohibited keyword (like "dynamic")
or ends in a country code; if the IP address, reverse DNS entry,
or envelope sender is listed in a blacklist; or if data is sent
before the SMTP greeting banner is displayed. spamdyke can also
limit recipients per connection, greylist for some or all domains,
and close connections that go idle or take too long.
