stunnel change log

Version 5.31, 2016.03.01, urgency: HIGH
* Security bugfixes
  - OpenSSL DLLs updated to version 1.0.2g.
    https://www.openssl.org/news/secadv_20160301.txt
* New features
  - Added logging the list of client CAs requested by the server.
  - Improved compatibility with the current OpenSSL 1.1.0-dev tree.
* Bugfixes
  - Only reset the watchdog if some data was actually transferred.
  - A workaround implemented for the unexpected exceptfds set by
    select() on WinCE 6.0 (thx to Richard Kraemer).

Version 5.30, 2016.01.28, urgency: HIGH
* Security bugfixes
  - OpenSSL DLLs updated to version 1.0.2f.
    https://www.openssl.org/news/secadv_20160128.txt
* New features
  - Improved compatibility with the current OpenSSL 1.1.0-dev tree.
  - Added OpenSSL autodetection for the recent versions of Xcode.
* Bugfixes
  - Fixed references to /etc removed from stunnel.init.in.
  - Stopped even trying -fstack-protector on unsupported platforms
    (thx to Rob Lockhart).

Version 5.29, 2016.01.08, urgency: LOW
* New features
  - New WIN32 icons.
  - Performance improvement: rwlocks used for locking with pthreads.
* Bugfixes
  - Compilation fix for *BSD.
  - Fixed configuration file reload for relative stunnel.conf path
    on Unix.
  - Fixed ignoring CRLfile unless CAfile was also specified (thx
    to Strukov Petr).

Version 5.28, 2015.12.11, urgency: HIGH
* New features
  - Build matrix (.travis.yml) extended with ./configure options.
  - mingw.mak updated to build tstunnel.exe (thx to Jose Alf.).
* Bugfixes
  - Fixed incomplete initialization.
  - Fixed UCONTEXT threading on OSX.
  - Fixed exit codes for information requests (as
    in "stunnel -version" or "stunnel -help").

Version 5.27, 2015.12.03, urgency: MEDIUM
* Security bugfixes
  - OpenSSL DLLs updated to version 1.0.2e.
    https://www.openssl.org/news/secadv_20151203.txt
* New features
  - Automated build testing configured with .travis.yml.
  - Added reading server certificates from hardware engines.
    For example: cert = id_45
  - Only attempt to use potentially harmful compiler or linker
    options if gcc was detected.
  - /opt/csw added to the OpenSSL directory lookup list.
  - mingw.mak updates (thx to Jose Alf.).
  - TODO list updated.

Version 5.26, 2015.11.06, urgency: MEDIUM
* Bugfixes
  - Compilation fixes for OSX, *BSD and Solaris.

Version 5.25, 2015.11.02, urgency: MEDIUM
* New features
  - SMTP client protocol negotiation support for
    "protocolUsername", "protocolPassword", and
    "protocolAuthentication" (thx to Douglas Harris).
  - New service-level option "config" to specify configuration
    commands introduced in OpenSSL 1.0.2 (thx to Stephen Wall).
  - The global option "foreground" now also accepts "quiet"
    parameter, which does not enable logging to stderr.
  - Manual page updated.
  - Obsolete OpenSSL engines removed from the Windows build:
    4758cca, aep, atalla, cswift, nuron, sureware.
  - Improved compatibility with the current OpenSSL 1.1.0-dev tree:
    gracefully handle symbols renamed from SSLeay* to OpenSSL*.
* Bugfixes
  - Fixed the "s_poll_wait returned 1, but no descriptor
    is ready" internal error.
  - Fixed "exec" hangs due to incorrect thread-local
    storage handling (thx to Philip Craig).
  - Fixed PRNG initialization (thx to Philip Craig).
  - Setting socket options no longer performed on PTYs.
  - Fixed 64-bit Windows build.

Version 5.24, 2015.10.08, urgency: MEDIUM
* New features
  - Custom CRL verification was replaced with the internal
    OpenSSL functionality.
  - *BSD support for "transparent = destination" and
    client-side "protocol = socks". This feature should
    work at least on FreeBSD, OpenBSD and OS X.
  - Added a new "protocolDomain" option for the NTLM
    authentication (thx to Andreas Botsikas).
  - Improved compatibility of the NTLM phase 1 message (thx
    to Andreas Botsikas).
  - "setuid" and "setgid" options are now also available
    in service sections.  They can be used to set owner
    and group of the Unix socket specified with "accept".
  - Added support for the new OpenSSL 1.0.2 SSL options.
  - Added OPENSSL_NO_EGD support (thx to Bernard Spil).
  - VC autodetection added to makew32.bat (thx to Andreas
    Botsikas).
* Bugfixes
  - Fixed the RESOLVE [F0] TOR extension support in SOCKS5.
  - Fixed the error code reported on the failed bind()
    requests.
  - Fixed the sequential log id with the FORK threading.
  - Restored the missing Microsoft.VC90.CRT.manifest file.

Version 5.23, 2015.09.02, urgency: LOW
* New features
  - Client-side support for the SOCKS protocol.
    See https://www.stunnel.org/socksvpn.html for details.
  - Reject SOCKS requests to connect loopback addresses.
  - New service-level option "OCSPnonce".
    The default value is "OCSPnonce = no".
  - Win32 directory structure rearranged.  The installer
    script provides automatic migration for common setups.
  - Added Win32 installer option to install stunnel for the
    current user only.  This feature does not deploy the NT
    service, but it also does not require aministrative
    privileges to install and configure stunnel.
  - stunnel.cnf was renamed to openssl.cnf in order to
    to prevent users from mixing it up with stunnel.conf.
  - Win32 desktop is automatically refreshed when the icon
    is created or removed.
  - The ca-certs.pem file is now updated on stunnel upgrade.
  - Inactive ports were removed from the PORTS file.
  - Added IPv6 support to the transparent proxy code.
* Bugfixes
  - Compilation fix for OpenSSL version older than 1.0.0.
  - Compilation fix for mingw.

Version 5.22, 2015.07.30, urgency: HIGH
* New features
  - "OCSPaia = yes" added to the configuration file templates.
  - Improved double free detection.
* Bugfixes
  - Fixed a number of OCSP bugs.  The most severe of those
    bugs caused stunnel to treat OCSP responses that failed
    OCSP_basic_verify() checks as if they were successful.
  - Fixed the passive IPv6 resolver (broken in stunnel 5.21).

Version 5.21, 2015.07.27, urgency: MEDIUM
* New features
  - Signal names are displayed instead of numbers.
  - First resolve IPv4 addresses on passive resolver requests.
    This speeds up stunnel startup on Win32 with a slow/defunct
    DNS service.
  - The "make check" target was modified to only build Win32
    executables when stunnel is built from a git repository (thx
    to Peter Pentchev).
  - More elaborate descriptions were added to the warning about
    using "verify = 2" without "checkHost" or "checkIP".
  - Performance optimization was performed on the debug code.
* Bugfixes
  - Fixed the FORK and UCONTEXT threading support.
  - Fixed "failover=prio" (broken since stunnel 5.15).
  - Added a retry when sleep(3) was interrupted by a signal
    in the cron thread scheduler.

Version 5.20, 2015.07.09, urgency: HIGH 
* Security bugfixes
  - OpenSSL DLLs updated to version 1.0.2d.
    https://www.openssl.org/news/secadv_20150709.txt
* New features
  - poll(2) re-enabled on MacOS X 10.5 and later.
  - Xcode SDK is automatically used on MacOS X if no other
    locally installed OpenSSL directory is found.
  - The SSL library detection algorithm was made a bit smarter.
  - Warnings about insecure authentication were modified to
    include the name of the affected service section.
  - A warning was added to stunnel.init if no pid file was
    specified in the configuration file (thx to Peter Pentchev).
  - Optional debugging symbols are included in the Win32 installer.
  - Documentation updates (closes Debian bug #781669).
* Bugfixes
  - Signal pipe reinitialization added to prevent turning the
    main accepting thread into a busy wait loop when an external
    condition breaks the signal pipe.  This bug was found to
    surface on Win32, but other platforms may also be affected.
  - Fixed removing the disabled taskbar icon.
  - Generated temporary DH parameters are used for configuration
    reload instead of the static defaults.
  - LSB compatibility fixes added to the stunnel.init script (thx
    to Peter Pentchev).
  - Fixed the manual page headers (thx to Gleydson Soares).

Version 5.19, 2015.06.16, urgency: MEDIUM:
* New features
  - OpenSSL DLLs updated to version 1.0.2c.
  - Added a runtime check whether COMP_zlib() method is implemented
    in order to improve compatibility with the Debian OpenSSL build.
* Bugfixes
  - Improved socket error handling.
  - Cron thread priority on Win32 platform changed to
    THREAD_PRIORITY_LOWEST to improve portability.
  - Makefile bugfixes for stunnel 5.18 regressions.
  - Fixed some typos in docs and scripts (thx to Peter Pentchev).
  - Fixed a log level check condition (thx to Peter Pentchev).

Version 5.18, 2015.06.12, urgency: MEDIUM:
* New features
  - OpenSSL DLLs updated to version 1.0.2b.
    https://www.openssl.org/news/secadv_20150611.txt
  - Added "include" configuration file option to include all
    configuration file parts located in a specified directory.
  - Log file is reopened every 24 hours.  With "log = overwrite"
    this feature can be used to prevent filling up disk space.
  - Temporary DH parameters are refreshed every 24 hours, unless
    static DH parameters were provided in the certificate file.
  - Unique initial DH parameters are distributed with each release.
  - Warnings are logged on potentially insecure authentication.
  - Improved compatibility with the current OpenSSL 1.1.0-dev tree:
    removed RLE compression support, etc.
  - Updated stunnel.spec (thx to Bill Quayle).
* Bugfixes
  - Fixed handling of dynamic connect targets.
  - Fixed handling of trailing whitespaces in the Content-Length
    header of the NTLM authentication.
  - Fixed --sysconfdir and --localstatedir handling (thx to
    Dagobert Michelsen).

Version 5.17, 2015.04.29, urgency: HIGH:
* Bugfixes
  - Fixed a NULL pointer dereference causing the service to crash.
    This bug was introduced in stunnel 5.15.

Version 5.16, 2015.04.19, urgency: MEDIUM:
* Bugfixes
  - Fixed compilation with old versions of gcc.

Version 5.15, 2015.04.16, urgency: LOW:
* New features
  - Added new service-level options "checkHost", "checkEmail" and
    "checkIP" for additional checks of the peer certificate subject.
    These options require OpenSSL version 1.0.2 or higher.
  - Win32 binary distribution now ships with the Mozilla root CA
    bundle.  This bundle is intended be used together with the new
    "checkHost" option to validate server certs accepted by Mozilla.
  - New commandline options "-reload" to reload the configuration
    file and "-reopen" to reopen the log file of stunnel running
    as a Windows service (thx to Marc McLaughlin).
  - Added session persistence based on negotiated TLS sessions.
    https://en.wikipedia.org/wiki/Load_balancing_%28computing%29#Persistence
    The current implementation does not support external TLS
    session caching with sessiond.
  - MEDIUM ciphers (currently SEED and RC4) are removed from the
    default cipher list.
  - The "redirect" option was improved to not only redirect sessions
    established with an untrusted certificate, but also sessions
    established without a client certificate.
  - OpenSSL version checking modified to distinguish FIPS and
    non-FIPS builds.
  - Improved compatibility with the current OpenSSL 1.1.0-dev tree.
  - Removed support for OpenSSL versions older than 0.9.7.
    The final update for the OpenSSL 0.9.6 branch was 17 Mar 2004.
  - "sessiond" support improved to also work in OpenSSL 0.9.7.
  - Randomize the initial value of the round-robin counter.
  - New stunnel.conf templates are provided for Windows and Unix.
* Bugfixes
  - Fixed compilation against old versions of OpenSSL.
  - Fixed memory leaks in certificate verification.

Version 5.14, 2015.03.25, urgency: HIGH:
* Security bugfixes
  - The "redirect" option now also redirects clients on SSL session
    reuse.  In stunnel versions 5.00 to 5.13 reused sessions were
    instead always connected hosts specified with the "connect"
    option regardless of their certificate verification result.
    This vulnerability was reported by Johan Olofsson.
* New features
  - Windows service is automatically restarted after upgrade.
* Bugfixes
  - Fixed a memory allocation error during Unix daemon shutdown.
  - Fixed handling multiple connect/redirect destinations.
  - OpenSSL FIPS builds are now correctly reported on startup.

Version 5.13, 2015.03.20, urgency: MEDIUM:
* New features
  - The "service" option was modified to also control the syslog
    service name.
* Bugfixes
  - Fixed Windows service crash.

Version 5.12, 2015.03.19, urgency: HIGH:
* Security bugfixes
  - OpenSSL DLLs updated to version 1.0.2a.
    https://www.openssl.org/news/secadv_20150319.txt
* New features
  - New service-level option "logId" to specify the
    connection identifier type.  Currently supported types:
    "sequential" (default), "unique", and "thread".
  - New service-level option "debug" to individually control
    logging verbosity of defined services.
* Bugfixes
  - OCSP fixed on Windows platform (thx to Alec Kosky).

Version 5.11, 2015.03.11, urgency: LOW:
* New features
  - OpenSSL DLLs updated to version 1.0.2.
  - Removed dereferences of internal OpenSSL data structures.
  - PSK key lookup algorithm performance improved from
    O(N) (linear) to O(log N) (logarithmic).
* Bugfixes
  - Fixed peer certificate list in the main window on Win32
    (thx to @fyer for reporting it).
  - Fixed console logging in tstunnel.exe.
  - _tputenv_s() replaced with more portable _tputenv() on Win32.

Version 5.10, 2015.01.22, urgency: LOW:
* New features
  - OCSP AIA (Authority Information Access) support.  This feature
    can be enabled with the new service-level option "OCSPaia".
  - Additional security features of the linker are enabled:
    "-z relro", "-z now", "-z noexecstack".
* Bugfixes
  - OpenSSL DLLs updated to version 1.0.1l.
    https://www.openssl.org/news/secadv_20150108.txt
  - FIPS canister updated to version 2.0.9 in the Win32 binary
    build.

Version 5.09, 2015.01.02, urgency: LOW:
* New features
  - Added PSK authentication with two new service-level
    configuration file options "PSKsecrets" and "PSKidentity".
  - Added additional security checks to the OpenSSL memory
    management functions.
  - Added support for the OPENSSL_NO_OCSP and OPENSSL_NO_ENGINE
    OpenSSL configuration flags.
  - Added compatibility with the current OpenSSL 1.1.0-dev tree.
* Bugfixes
  - Removed defective s_poll_error() code occasionally causing
    connections to be prematurely closed (truncated).
    This bug was introduced in stunnel 4.34.
  - Fixed ./configure systemd detection (thx to Kip Walraven).
  - Fixed ./configure sysroot detection (thx to Kip Walraven).
  - Fixed compilation against old versions of OpenSSL.
  - Removed outdated French manual page.

Version 5.08, 2014.12.09, urgency: MEDIUM:
* New features
  - Added SOCKS4/SOCKS4a protocol support.
  - Added SOCKS5 protocol support.
  - Added SOCKS RESOLVE [F0] TOR extension support.
  - Updated automake to version 1.14.1.
  - OpenSSL directory searching is now relative to the sysroot.
* Bugfixes
  - Fixed improper hangup condition handling.
  - Fixed missing -pic linker option.  This is required for
    Android 5.0 and improves security.

Version 5.07, 2014.11.01, urgency: MEDIUM:
* New features
  - Several SMTP server protocol negotiation improvements.
  - Added UTF-8 byte order marks to stunnel.conf templates.
  - DH parameters are no longer generated by "make cert".
    The hardcoded DH parameters are sufficiently secure,
    and modern TLS implementations will use ECDH anyway.
  - Updated manual for the "options" configuration file option.
  - Added support for systemd 209 or later.
  - New --disable-systemd ./configure option.
  - setuid/setgid commented out in stunnel.conf-sample.
* Bugfixes
  - Added support for UTF-8 byte order mark in stunnel.conf.
  - Compilation fix for OpenSSL with disabled SSLv2 or SSLv3.
  - Non-blocking mode set on inetd and systemd descriptors.
  - shfolder.h replaced with shlobj.h for compatibility
    with modern Microsoft compilers.

Version 5.06, 2014.10.15, urgency: HIGH:
* Security bugfixes
  - OpenSSL DLLs updated to version 1.0.1j.
    https://www.openssl.org/news/secadv_20141015.txt
  - The insecure SSLv2 protocol is now disabled by default.
    It can be enabled with "options = -NO_SSLv2".
  - The insecure SSLv3 protocol is now disabled by default.
    It can be enabled with "options = -NO_SSLv3".
  - Default sslVersion changed to "all" (also in FIPS mode)
    to autonegotiate the highest supported TLS version.
* New features
  - Added missing SSL options to match OpenSSL 1.0.1j.
  - New "-options" commandline option to display the list
    of supported SSL options.
* Bugfixes
  - Fixed FORK threading build regression bug.
  - Fixed missing periodic Win32 GUI log updates.

Version 5.05, 2014.10.10, urgency: MEDIUM:
* New features
  - Asynchronous communication with the GUI thread for faster
    logging on Win32.
  - systemd socket activation (thx to Mark Theunissen).
  - The parameter of "options" can now be prefixed with "-"
    to clear an SSL option, for example:
    "options = -LEGACY_SERVER_CONNECT".
  - Improved "transparent = destination" manual page (thx to
    Vadim Penzin).
* Bugfixes
  - Fixed POLLIN|POLLHUP condition handling error resulting
    in prematurely closed (truncated) connection.
  - Fixed a null pointer dereference regression bug in the
    "transparent = destination" functionality (thx to
    Vadim Penzin). This bug was introduced in stunnel 5.00.
  - Fixed startup thread synchronization with Win32 GUI.
  - Fixed erroneously closed stdin/stdout/stderr if specified
    as the -fd commandline option parameter.
  - A number of minor Win32 GUI bugfixes and improvements.
  - Merged most of the Windows CE patches (thx to Pierre Delaage).
  - Fixed incorrect CreateService() error message on Win32.
  - Implemented a workaround for defective Cygwin file
    descriptor passing breaking the libwrap support:
    http://wiki.osdev.org/Cygwin_Issues#Passing_file_descriptors

Version 5.04, 2014.09.21, urgency: LOW:
* New features
  - Support for local mode ("exec" option) on Win32.
  - Support for UTF-8 config file and log file.
  - Win32 UTF-16 build (thx to Pierre Delaage for support).
  - Support for Unicode file names on Win32.
  - A more explicit service description provided for the
    Windows SCM (thx to Pierre Delaage).
  - TCP/IP dependency added for NT service in order to prevent
    initialization failure at boot time.
  - FIPS canister updated to version 2.0.8 in the Win32 binary
    build.
* Bugfixes
  - load_icon_default() modified to return copies of default icons
    instead of the original resources to prevent the resources
    from being destroyed.
  - Partially merged Windows CE patches (thx to Pierre Delaage).
  - Fixed typos in stunnel.init.in and vc.mak.
  - Fixed incorrect memory allocation statistics update in
    str_realloc().
  - Missing REMOTE_PORT environmental variable is provided to
    processes spawned with "exec" on Unix platforms.
  - Taskbar icon is no longer disabled for NT service.
  - Fixed taskbar icon initialization when commandline options are
    specified.
  - Reportedly more compatible values used for the dwDesiredAccess
    parameter of the CreateFile() function (thx to Pierre Delaage).
  - A number of minor Win32 GUI bugfixes and improvements.

Version 5.03, 2014.08.07, urgency: HIGH:
* Security bugfixes
  - OpenSSL DLLs updated to version 1.0.1i.
    See https://www.openssl.org/news/secadv_20140806.txt
* New features
  - FIPS autoconfiguration cleanup.
  - FIPS canister updated to version 2.0.6.
  - Improved SNI diagnostic logging.
* Bugfixes
  - Compilation fixes for old versions of OpenSSL.
  - Fixed whitespace handling in the stunnel.init script.

Version 5.02, 2014.06.09, urgency: HIGH:
* Security bugfixes
  - OpenSSL DLLs updated to version 1.0.1h.
    See https://www.openssl.org/news/secadv_20140605.txt
* New features
  - Major rewrite of the protocol.c interface: it is now possible to add
    protocol negotiations at multiple connection phases, protocols can
    individually decide whether the remote connection will be
    established before or after SSL/TLS is negotiated.
  - Heap memory blocks are wiped before release.  This only works for
    block allocated by stunnel, and not by OpenSSL or other libraries.
  - The safe_memcmp() function implemented with execution time not
    dependent on the compared data.
  - Updated the stunnel.conf and stunnel.init templates.
  - Added a client-mode example to the manual.
* Bugfixes
  - Fixed "failover = rr" broken since version 5.00.
  - Fixed "taskbar = no" broken since version 5.00.
  - Compilation fix for missing SSL_OP_MSIE_SSLV2_RSA_PADDING option.

Version 5.01, 2014.04.08, urgency: HIGH:
* Security bugfixes
  - OpenSSL DLLs updated to version 1.0.1g.
    This version mitigates TLS heartbeat read overrun (CVE-2014-0160).
* New features
  - X.509 extensions added to the created self-signed stunnel.pem.
  - "FIPS = no" also allowed in non-FIPS builds of stunnel.
  - Search all certificates with the same subject name for a matching
    public key rather than only the first one (thx to Leon Winter).
  - Create logs in the local application data folder if stunnel folder
    is not writable on Win32.
* Bugfixes
  - close_notify not sent when SSL still has some data buffered.
  - Protocol negotiation with server-side SNI fixed.
  - A Mac OS X missing symbols fixed.
  - Win32 configuration file reload crash fixed.
  - Added s_pool_free() on exec+connect service retires.
  - Line-buffering enforced on stderr output.

stunnel 5.00 disables some features previously enabled by default.
Users should review whether the new defaults are appropriate for their
particular deployments.  Packages maintainers may consider prepending
the old defaults for "fips" (if supported by their OpenSSL library),
"pid" and "libwrap" to stunnel.conf during automated updates.

Version 5.00, 2014.03.06, urgency: HIGH:
* Security bugfixes
  - Added PRNG state update in fork threading (CVE-2014-0016).
* New global configuration file defaults
  - Default "fips" option value is now "no", as FIPS mode is only
    helpful for compliance, and never for actual security.
  - Default "pid" is now "", i.e. not to create a pid file at startup.
* New service-level configuration file defaults
  - Default "ciphers" updated to "HIGH:MEDIUM:+3DES:+DH:!aNULL:!SSLv2"
    due to AlFBPPS attack and bad performance of DH ciphersuites.
  - Default "libwrap" setting is now "no" to improve performance.
* New features
  - OpenSSL DLLs updated to version 1.0.1f.
  - zlib DLL updated to version 1.2.8.
  - autoconf scripts upgraded to version 2.69.
  - TLS 1.1 and TLS 1.2 are now allowed in the FIPS mode.
  - New service-level option "redirect" to redirect SSL client
    connections on authentication failures instead of rejecting them.
  - New global "engineDefault" configuration file option to control
    which OpenSSL tasks are delegated to the current engine.
    Available tasks: ALL, RSA, DSA, ECDH, ECDSA, DH, RAND, CIPHERS,
    DIGESTS, PKEY, PKEY_CRYPTO, PKEY_ASN1.
  - New service-level configuration file option "engineId" to select
    the engine by identifier, e.g. "engineId = capi".
  - New global configuration file option "log" to control whether to
    append (the default), or to overwrite log file while (re)opening.
  - Different taskbar icon colors to indicate the service state.
  - New global configuration file options "iconIdle", "iconActive",
    and "iconError" to select status icon on GUI taskbar.
  - Removed the limit of 63 stunnel.conf sections on Win32 platform.
  - Installation of a sample certificate was moved to a separate "cert"
    target in order to allow unattended (e.g. scripted) installations.
  - Reduced length of the logged thread identifier.  It is still based
    on the OS thread ID, and thus not unique over long periods of time.
  - Improved readability of error messages printed when stunnel refuses
    to start due to a critical error.
* Bugfixes
  - LD_PRELOAD Solaris compatibility bug fixed (thx to Norm Jacobs).
  - CRYPTO_NUM_LOCKS replaced with CRYPTO_num_locks() to improve binary
    compatibility with diverse builds of OpenSSL (thx to Norm Jacobs).
  - Corrected round-robin failover behavior under heavy load.
  - Numerous fixes in the engine support code.
  - On Win32 platform .rnd file moved from c:\ to the stunnel folder.

Version 4.57, 2015.04.01, urgency: HIGH:
* Security bugfixes
  - Added PRNG state update in fork threading (CVE-2014-0016).

Version 4.56, 2013.03.22, urgency: HIGH:
* New features
  - Win32 installer automatically configures firewall exceptions.
  - Win32 installer configures administrative shortcuts to invoke UAC.
  - Improved Win32 GUI shutdown time.
* Bugfixes
  - Fixed a regression bug introduced in version 4.55 causing random
    crashes on several platforms, including Windows 7.
  - Fixed startup crashes on some Win32 systems.
  - Fixed incorrect "stunnel -exit" process synchronisation.
  - Fixed FIPS detection with new versions of the OpenSSL library.
  - Failure to open the log file at startup is no longer ignored.

Version 4.55, 2013.03.03, urgency: HIGH:
* Security bugfixes
  - Buffer overflow vulnerability fixed in the NTLM authentication
    of the CONNECT protocol negotiation.
    See https://www.stunnel.org/CVE-2013-1762.html for details.
  - OpenSSL updated to version 1.0.1e in Win32/Android builds.
* New features
  - SNI wildcard matching in server mode.
  - Terminal version of stunnel (tstunnel.exe) build for Win32.
* Bugfixes
  - Fixed write half-close handling in the transfer() function (thx to
    Dustin Lundquist).
  - Fixed EAGAIN error handling in the transfer() function (thx to Jan Bee).
  - Restored default signal handlers before execvp() (thx to Michael Weiser).
  - Fixed memory leaks in protocol negotiation (thx to Arthur Mesh).
  - Fixed a file descriptor leak during configuration file reload (thx to
    Arthur Mesh).
  - Closed SSL sockets were removed from the transfer() c->fds poll.
  - Minor fix in handling exotic inetd-mode configurations.
  - WCE compilation fixes.
  - IPv6 compilation fix in protocol.c.
  - Windows installer fixes.

Version 4.54, 2012.10.09, urgency: MEDIUM:
* New Win32 features
  - FIPS module updated to version 2.0.
  - OpenSSL DLLs updated to version 1.0.1c.
  - zlib DLL updated to version 1.2.7.
  - Engine DLLs added: 4758cca, aep, atalla, capi, chil, cswift, gmp, gost,
    nuron, padlock, sureware, ubsec.
* Other new features
  - "session" option renamed to more readable "sessionCacheTimeout".
    The old name remains accepted for backward compatibility.
  - New service-level "sessionCacheSize" option to control session cache size.
  - New service-level option "reset" to control whether TCP RST flag is used
    to indicate errors.  The default value is "reset = yes".
  - New service-level option "renegotiation" to disable SSL renegotiation.
    This feature is based on a public-domain patch by Janusz Dziemidowicz.
  - New FreeBSD socket options: IP_FREEBIND, IP_BINDANY, IPV6_BINDANY (thx
    to Janusz Dziemidowicz).
  - New parameters to configure TLS v1.1/v1.2 with OpenSSL version 1.0.1
    or higher (thx to Henrik Riomar).
* Bugfixes
  - Fixed "Application Failed to Initialize Properly (0xc0150002)" error.
  - Fixed missing SSL state debug log entries.
  - Fixed a race condition in libwrap code resulting in random stalls (thx
    to Andrew Skalski).
  - Session cache purged at configuration file reload to reduce memory leak.
    Remaining leak of a few kilobytes per section is yet to be fixed.
  - Fixed a regression bug in "transparent = destination" functionality (thx
    to Stefan Lauterbach). This bug was introduced in stunnel 4.51.
  - "transparent = destination" is now a valid endpoint in inetd mode.
  - "delay = yes" fixed to work even if specified *after* "connect" option.
  - Multiple "connect" targets fixed to also work with delayed resolver.
  - The number of resolver retries of EAI_AGAIN error has been limited to 3
    in order to prevent infinite loops.

Version 4.53, 2012.03.19, urgency: MEDIUM:
* New features
  - Added client-mode "sni" option to directly control the value of
    TLS Server Name Indication (RFC 3546) extension.
  - Added support for IP_FREEBIND socket option with a pached Linux kernel.
  - Glibc-specific dynamic allocation tuning was applied to help unused memory
    deallocation.
  - Non-blocking OCSP implementation.
* Bugfixes
  - Compilation fixes for old versions of OpenSSL (tested against 0.9.6).
  - Usage of uninitialized variables fixed in exec+connect services.
  - Occasional logging subsystem crash with exec+connect services.
  - OpenBSD compilation fix (thx to Michele Orru').
  - Session id context initialized with session name rather than a constant.
  - Fixed handling of a rare inetd mode use case, where either stdin or stdout
    is a socket, but not both of them at the same time.
  - Fixed missing OPENSSL_Applink http://www.openssl.org/support/faq.html#PROG2
  - Fixed crash on termination with FORK threading model.
  - Fixed dead canary after configuration reload with open connections.
  - Fixed missing file descriptors passed to local mode processes.
  - Fixed required jmp_buf alignment on Itanium platform.
  - Removed creating /dev/zero in the chroot jail on Solaris platform.
  - Fixed detection of WSAECONNREFUSED Winsock error.
  - Missing Microsoft.VC90.CRT.manifest added to Windows installer.

Version 4.52, 2012.01.12, urgency: MEDIUM:
* Bugfixes
  - Fixed write closure notification for non-socket file descriptors.
  - Removed a line logged to stderr in inetd mode.
  - Fixed "Socket operation on non-socket" error in inetd mode on Mac OS X
    platform.
  - Removed direct access to the fields of the X509_STORE_CTX data structure.

Version 4.51, 2012.01.09, urgency: MEDIUM:
* New features
  - Updated Win32 binary distribution OpenSSL DLLs to version 0.9.8s-fips.
  - Updated Android binary OpenSSL to version 1.0.0f.
  - Zlib support added to Win32 and Android binary builds.
  - New "compression = deflate" global option to enable RFC 2246 compresion.
    For compatibility with previous versions "compression = zlib" and
    "compression = rle" also enable the deflate (RFC 2246) compression.
  - Compression is disabled by default.
  - Separate default ciphers and sslVersion for "fips = yes" and "fips = no".
  - UAC support for editing configuration file with Windows GUI.
* Bugfixes
  - Fixed exec+connect sections.
  - Added a workaround for broken Android getaddrinfo():
    http://stackoverflow.com/questions/7818246/segmentation-fault-in-getaddrinfo

Version 4.50, 2011.12.03, urgency: MEDIUM:
* New features
  - Added Android port.
  - Updated INSTALL.FIPS.
* Bugfixes
  - Fixed internal memory allocation problem in inetd mode.
  - Fixed FIPS mode on Microsoft Vista, Server 2008, and Windows 7.
    This fix required to compile OpenSSL FIPS-compliant DLLs with MSVC 9.0,
    instead of MSVC 10.0.  msvcr100.dll was replaced with msvcr90.dll.
    GPL compatibility issues are explained in the GPL FAQ:
    http://www.gnu.org/licenses/gpl-faq.html#WindowsRuntimeAndGPL
  - POP3 server-side protocol negotiation updated to report STLS
    capability (thx to Anthony Morgan).

Version 4.49, 2011.11.28, urgency: MEDIUM:
* Bugfixes
  - Missing Microsoft Visual C++ Redistributable (msvcr100.dll) required
    by FIPS-compliant OpenSSL library was added to the Windows installer.
  - A bug was fixed causing crashes on MacOS X and some other platforms.

Version 4.48, 2011.11.26, urgency: MEDIUM:
* New features
  - FIPS support on Win32 platform added.  OpenSSL 0.9.8r DLLs based on
    FIPS 1.2.3 canister are included with this version of stunnel.  FIPS
    mode can be disabled with "fips = no" configuration file option.
* Bugfixes
  - Fixed canary initialization problem on Win32 platform.

Version 4.47, 2011.11.21, urgency: MEDIUM:
* Internal improvements
  - CVE-2010-3864 workaround improved to check runtime version of OpenSSL
    rather than compiled version, and to allow OpenSSL 0.x.x >= 0.9.8p.
  - Encoding of man page sources changed to UTF-8.
* Bugfixes
  - Handling of socket/SSL close in transfer() function was fixed.
  - Logging was modified to save and restore system error codes.
  - Option "service" was restricted to Unix, as since stunnel 4.42 it
    wasn't doing anything useful on Windows platform.

Version 4.46, 2011.11.04, urgency: LOW:
* New features
  - Added Unix socket support (e.g. "connect = /var/run/stunnel/socket").
  - Added "verify = 4" mode to ignore CA chain and only verify peer certificate.
  - Removed the limit of 16 IP addresses for a single 'connect' option.
  - Removed the limit of 256 stunnel.conf sections in PTHREAD threading model.
    It is still not possible have more than 63 sections on Win32 platform.
    http://msdn.microsoft.com/en-us/library/windows/desktop/ms740141(v=vs.85).aspx
* Optimizations
  - Reduced per-connection memory usage.
  - Performed a major refactoring of internal data structures.  Extensive
    internal testing was performed, but some regression bugs are expected.
* Bugfixes
  - Fixed Win32 compilation with Mingw32.
  - Fixed non-blocking API emulation layer in UCONTEXT threading model.
  - Fixed signal handling in UCONTEXT threading model.

Version 4.45, 2011.10.24, urgency: LOW:
* New features
  - "protocol = proxy" support to send original client IP address to haproxy:
    http://haproxy.1wt.eu/download/1.5/doc/proxy-protocol.txt
    This requires accept-proxy bind option of haproxy 1.5-dev3 or later.
  - Added Win32 configuration reload without a valid configuration loaded.
  - Added compatibility with LTS OpenSSL versions 0.9.6 and 0.9.7.
    Some features are only available in OpenSSL 1.0.0 and later.
* Performance optimizations
  - Use SSL_MODE_RELEASE_BUFFERS if supported by the OpenSSL library.
  - Libwrap helper processes are no longer started if libwrap is disabled
    in all sections of the configuration file.
* Internal improvements
  - Protocol negotiation framework was rewritten to support additional
    code to be executed after SSL_accept()/SSL_connect().
  - Handling of memory allocation errors was rewritten to gracefully
    terminate the process (thx to regenrecht for the idea).
* Bugfixes
  - Fixed -l option handling in stunnel3 script (thx to Kai Gülzau).
  - Script to build default stunnel.pem was fixed (thx to Sebastian Kayser).
  - MinGW compilation script (mingw.mak) was fixed (thx to Jose Alf).
  - MSVC compilation script (vc.mak) was fixed.
  - A number of problems in WINSOCK error handling were fixed.

Version 4.44, 2011.09.17, urgency: MEDIUM:
* New features
  - Major automake/autoconf cleanup.
  - Heap buffer overflow protection with canaries.
  - Stack buffer overflow protection with -fstack-protector.
* Bugfixes
  - Fixed garbled error messages on errors with setuid/setgid options.
  - SNI fixes (thx to Alexey Drozdov).
  - Use after free in fdprintf() (thx to Alexey Drozdov).
    This issue might cause GPF with "protocol" or "ident" options.

Version 4.43, 2011.09.07, urgency: MEDIUM:
* New features
  - Updated Win32 DLLs for OpenSSL 1.0.0e.
  - Major optimization of the logging subsystem.
    Benchmarks indicate up to 15% stunnel performance improvement.
* Bugfixes
  - Fixed Win32 configuration file reload.
  - Fixed FORK and UCONTEXT threading models.
  - Corrected INSTALL.W32 file.

Version 4.42, 2011.08.18, urgency: HIGH:
* New features
  - New verify level 0 to request and ignore peer certificate.  This
    feature is useful with the new Windows GUI menu to save cached peer
    certificate chains, as SSL client certificates are not sent by default.
  - Manual page has been updated.
  - Removed support for changing Windows Service name with "service" option.
* Bugfixes
  - Fixed a heap corruption vulnerability in versions 4.40 and 4.41.  It may
    possibly be leveraged to perform DoS or remote code execution attacks.
  - The -quiet commandline option was applied to *all* message boxes.
  - Silent install (/S option) no longer attempts to create stunnel.pem.

Version 4.41, 2011.07.25, urgency: MEDIUM:
* Bugfixes
  - Fixed Windows service crash of stunnel 4.40.

Version 4.40, 2011.07.23, urgency: LOW:
* New Win32 features
  - Added a GUI menu to save cached peer certificate chains.
  - Added comandline "-exit" option to stop stunnel *not* running
    as a service.  This option may be useful for scripts.
  - Added file version information to stunnel.exe.
  - A number of other GUI improvements.
* Other new features
  - Hardcoded 2048-bit DH parameters are used as a fallback if DH parameters
    are not provided in stunnel.pem.
  - Default "ciphers" value updated to prefer ECDH:
    "ALL:!SSLv2:!aNULL:!EXP:!LOW:-MEDIUM:RC4:+HIGH".
  - Default ECDH curve updated to "prime256v1".
  - Removed support for temporary RSA keys (used in obsolete export ciphers).

Version 4.39, 2011.07.06, urgency: LOW:
* New features
  - New Win32 installer module to build self-signed stunnel.pem.
  - Added configuration file editing with Windows GUI.
  - Added log file reopening file editing with Windows GUI.
    It might be useful to also implement log file rotation.
  - Improved configuration file reload with Windows GUI.

Version 4.38, 2011.06.28, urgency: MEDIUM:
* New features
  - Server-side SNI implemented (RFC 3546 section 3.1) with a new
    service-level option "nsi".
  - "socket" option also accepts "yes" and "no" for flags.
  - Nagle's algorithm is now disabled by default for improved interactivity.
* Bugfixes
  - A compilation fix was added for OpenSSL version < 1.0.0.
  - Signal pipe set to non-blocking mode.  This bug caused hangs of stunnel
    features based on signals, e.g. local mode, FORK threading, or
    configuration file reload on Unix.  Win32 platform was not affected.

Version 4.37, 2011.06.17, urgency: MEDIUM:
* New features
  - Client-side SNI implemented (RFC 3546 section 3.1).
  - Default "ciphers" changed from the OpenSSL default to a more secure
    and faster "RC4-MD5:HIGH:!aNULL:!SSLv2".
    A paranoid (and usually slower) setting would be "HIGH:!aNULL:!SSLv2".
  - Recommended "options = NO_SSLv2" added to the sample stunnel.conf file.
  - Default client method upgraded from SSLv3 to TLSv1.
    To connect servers without TLS support use "sslVersion = SSLv3" option.
  - Improved --enable-fips and --disable-fips ./configure option handling.
  - On startup stunnel now compares the compiled version of OpenSSL against
    the running version of OpenSSL. A warning is logged on mismatch.
* Bugfixes
  - Non-blocking socket handling in local mode fixed (Debian bug #626856).
  - UCONTEXT threading mode fixed.
  - Removed the use of gcc Thread-Local Storage for improved portability.
  - va_copy macro defined for platforms that do not have it.
  - Fixed "local" option parsing on IPv4 systems.
  - Solaris compilation fix (redefinition of "STR").

Version 4.36, 2011.05.03, urgency: LOW:
* New features
  - Updated Win32 DLLs for OpenSSL 1.0.0d.
  - Dynamic memory management for strings manipulation:
    no more static STRLEN limit, lower stack footprint.
  - Strict public key comparison added for "verify = 3" certificate
    checking mode (thx to Philipp Hartwig).
  - Backlog parameter of listen(2) changed from 5 to SOMAXCONN:
    improved behavior on heavy load.
  - Example tools/stunnel.service file added for systemd service manager.
* Bugfixes
  - Missing pthread_attr_destroy() added to fix memory leak (thx to
    Paul Allex and Peter Pentchev).
  - Fixed the incorrect way of setting FD_CLOEXEC flag.
  - Fixed --enable-libwrap option of ./configure script.
  - /opt/local added to OpenSSL search path for MacPorts compatibility.
  - Workaround implemented for signal handling on MacOS X.
  - A trivial bug fixed in the stunnel.init script.
  - Retry implemented on EAI_AGAIN error returned by resolver calls.

Version 4.35, 2011.02.05, urgency: LOW:
* New features
  - Updated Win32 DLLs for OpenSSL 1.0.0c.
  - Transparent source (non-local bind) added for FreeBSD 8.x.
  - Transparent destination ("transparent = destination") added for Linux.
* Bugfixes
  - Fixed reload of FIPS-enabled stunnel.
  - Compiler options are now auto-detected by ./configure script
    in order to support obsolete versions of gcc.
  - Async-signal-unsafe s_log() removed from SIGTERM/SIGQUIT/SIGINT handler.
  - CLOEXEC file descriptor leaks fixed on Linux >= 2.6.28 with glibc >= 2.10.
    Irreparable race condition leaks remain on other Unix platforms.
    This issue may have security implications on some deployments:
    http://udrepper.livejournal.com/20407.html
  - Directory lib64 included in the OpenSSL library search path.
  - Windows CE compilation fixes (thx to Pierre Delaage).
  - Deprecated RSA_generate_key() replaced with RSA_generate_key_ex().
* Domain name changes (courtesy of Bri Hatch)
  - http://stunnel.mirt.net/ --> http://www.stunnel.org/
  - ftp://stunnel.mirt.net/ --> http://ftp.stunnel.org/
  - stunnel.mirt.net::stunnel --> rsync.stunnel.org::stunnel
  - stunnel-users@mirt.net --> stunnel-users@stunnel.org
  - stunnel-announce@mirt.net --> stunnel-announce@stunnel.org

Version 4.34, 2010.09.19, urgency: LOW:
* New features
  - Updated Win32 DLLs for OpenSSL 1.0.0a.
  - Updated Win32 DLLs for zlib 1.2.5.
  - Updated automake to version 1.11.1
  - Updated libtool to version 2.2.6b
  - Added ECC support with a new service-level "curve" option.
  - DH support is now enabled by default.
  - Added support for OpenSSL builds with some algorithms disabled.
  - ./configure modified to support cross-compilation.
  - Sample stunnel.init updated based on Debian init script.
* Bugfixes
  - Implemented fixes in user interface to enter engine PIN.
  - Fixed a transfer() loop issue on socket errors.
  - Fixed missing Win32 taskbar icon while displaying a global option error.

Version 4.33, 2010.04.05, urgency: MEDIUM:
* New features
  - Win32 DLLs for OpenSSL 1.0.0.
    This library requires to c_rehash CApath/CRLpath directories on upgrade.
  - Win32 DLLs for zlib 1.2.4.
  - Experimental support for local mode on Win32 platform.
    Try "exec = c:\windows\system32\cmd.exe".
* Bugfixes
  - Inetd mode fixed.

Version 4.32, 2010.03.24, urgency: MEDIUM:
* New features
  - New service-level "libwrap" option for run-time control whether
    /etc/hosts.allow and /etc/hosts.deny are used for access control.
    Disabling libwrap significantly increases performance of stunnel.
  - Win32 DLLs for OpenSSL 0.9.8m.
* Bugfixes
  - Fixed a transfer() loop issue with SSLv2 connections.
  - Fixed a "setsockopt IP_TRANSPARENT" warning with "local" option.
  - Logging subsystem bugfixes and cleanup.
  - Installer bugfixes for Vista and later versions of Windows.
  - FIPS mode can be enabled/disabled at runtime.

Version 4.31, 2010.02.03, urgency: MEDIUM:
* New features
  - Log file reopen on USR1 signal was added.
* Bugfixes
  - Some regression issues introduced in 4.30 were fixed.

Version 4.30, 2010.01.21, urgency: LOW/EXPERIMENTAL:
* New features
  - Graceful configuration reload with HUP signal on Unix
    and with GUI on Windows.

Version 4.29, 2009.12.02, urgency: MEDIUM:
* New feature sponsored by Searchtech Limited http://www.astraweb.com/
  - sessiond, a high performance SSL session cache was built for stunnel.
    A new service-level "sessiond" option was added.  sessiond is
    available for download on ftp://ftp.stunnel.org/stunnel/sessiond/ .
    stunnel clusters will be a lot faster, now!
* Bugfixes
  - "execargs" defaults to the "exec" parameter (thx to Peter Pentchev).
  - Compilation fixes added for AIX and old versions of OpenSSL.
  - Missing "fips" option was added to the manual.

Version 4.28, 2009.11.08, urgency: MEDIUM:
* New features
  - Win32 DLLs for OpenSSL 0.9.8l.
  - Transparent proxy support on Linux kernels >=2.6.28.
    See the manual for details.
  - New socket options to control TCP keepalive on Linux:
    TCP_KEEPCNT, TCP_KEEPIDLE, TCP_KEEPINTVL.
  - SSL options updated for the recent version of OpenSSL library.
* Bugfixes
  - A serious bug in asynchronous shutdown code fixed.
  - Data alignment updated in libwrap.c.
  - Polish manual encoding fixed.
  - Notes on compression implementation in OpenSSL added to the manual.

Version 4.27, 2009.04.16, urgency: MEDIUM:
* New features
  - Win32 DLLs for OpenSSL 0.9.8k.
  - FIPS support was updated for openssl-fips 1.2.
  - New priority failover strategy for multiple "connect" targets,
    controlled with "failover=rr" (default) or "failover=prio".
  - pgsql protocol negotiation by Marko Kreen <markokr@gmail.com>.
  - Building instructions were updated in INSTALL.W32 file.
* Bugfixes
  - Libwrap helper processes fixed to close standard
    input/output/error file descriptors.
  - OS2 compilation fixes.
  - WCE fixes by Pierre Delaage <delaage.pierre@free.fr>.

Version 4.26, 2008.09.20, urgency: MEDIUM:
* New features
  - Win32 DLLs for OpenSSL 0.9.8i.
  - /etc/hosts.allow and /etc/hosts.deny no longer need to be
    copied to the chrooted directory, as the libwrap processes
    are no longer chrooted.
  - A more informative error messages for invalid port number
    specified in stunnel.conf file.
  - Support for Microsoft Visual C++ 9.0 Express Edition.
* Bugfixes
  - Killing all libwrap processes at stunnel shutdown fixed.
  - A minor bug in stunnel.init sample SysV startup file fixed.

Version 4.25, 2008.06.01, urgency: MEDIUM:
* New features
  - Win32 DLLs for OpenSSL 0.9.8h.
* Bugfixes
  - Spawning libwrap processes delayed until privileges are dropped.
  - Compilation fix for systems without struct msghdr.msg_control.

Version 4.24, 2008.05.19, urgency: HIGH:
* Bugfixes
  - OCSP code was fixed to properly reject revoked certificates.
