libtls-sys 1.2.0

FFI bindings for LibreSSL's libtls.
Documentation
Because this project is maintained both in the OpenBSD tree using CVS and in
Git, it can be confusing following all of the changes.

Most of the libssl and libcrypto source code is is here in OpenBSD CVS:

	http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/lib/libssl/

Some of the libcrypto and OS-compatibility files for entropy and random number
generation are here:

	http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/lib/libcrypto/

A simplified TLS wrapper library is here:

	http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/lib/libtls/

The LibreSSL Portable project copies these portions of the OpenBSD tree, along
with relevant portions of the C library, to a Git repository. This makes it
easier to follow all of the relevant changes to the upstream project in a
single place:

	https://github.com/libressl-portable/openbsd

The portable bits of the project are largely maintained out-of-tree, and their
history is also available from Git.

	https://github.com/libressl-portable/portable

LibreSSL Portable Release Notes:

3.1.0 - Development release

	* Completed initial TLS 1.3 implementation with a completely new state
	  machine and record layer. TLS 1.3 is now enabled by default for the
	  client side, with the server side to be enabled in a future release.
	  Note that the OpenSSL TLS 1.3 API is not yet visible/available.

	* Many more code cleanups, fixes, and improvements to memory handling
	  and protocol parsing.

	* Added RSA-PSS and RSA-OAEP methods from OpenSSL 1.1.1.

	* Ported Cryptographic Message Syntax (CMS) implementation from OpenSSL
	  1.1.1 and enabled by default.

	* Improved compatibility by backporting functionality and documentation
	  from OpenSSL 1.1.1.

	* Added many new additional crypto test vectors.

	* Adjusted EVP_chacha20()'s behavior to match OpenSSL's semantics.

	* Default CA bundle location is now configurable in portable builds.

	* Added cms subcommand to openssl(1).

	* Added -addext option to openssl(1) req subcommand.

3.0.2 - Stable release

	* Use a valid curve when constructing an EC_KEY that looks like X25519.
	  The recent EC group cofactor change results in stricter validation,
	  which causes the EC_GROUP_set_generator() call to fail.
	  Issue reported and fix tested by rsadowski@

	* Fixed a padding oracle in PKCS7_dataDecode and CMS_decrypt_set1_pkey.
	  (Note that the CMS code is currently disabled)
	  Port of Edlinger's Fix for CVE-2019-1563 from OpenSSL 1.1.1 (old license) 

	* Avoid a path traversal bug in s_server on Windows when run with the -WWW
	  or -HTTP options, due to incomplete path check logic.
	  Issue reported and fix tested by Jobert Abma

3.0.1 - Development release

	* Ported Billy Brumley's fix for CVE-2019-1547 in OpenSSL 1.1.1. If a NULL
	  or zero cofactor is passed to EC_GROUP_set_generator(), try to compute
	  it using Hasse's bound. This works as long as the cofactor is small
	  enough.

	* Fixed a memory leak in error paths for eckey_type2param().

	* Initial work on supporting Cryptographic Message Syntax (CMS) in
	  libcrypto (not enabled).

	* Various manual page improvements and additions.

	* Added a CMake check for an existing uninstall target, facilitating
	  embedding LibreSSL in larger CMake projects, from Matthew Albrecht.

3.0.0 - Development release

	* Completed the port of RSA_METHOD accessors from the OpenSSL 1.1 API.

	* Documented undescribed options and removed unfunctional options
	  description in openssl(1) manual.

	* A plethora of small fixes due to regular oss-fuzz testing.

	* Various side channels in DSA and ECDSA were addressed.  These are some of
	  the many issues found in an extensive systematic analysis of bignum usage
	  by Samuel Weiser, David Schrammel et al.

	* Enabled openssl(1) speed subcommand on Windows platform.

	* Enabled performance optimizations when building with Visual Studio on Windows.

	* Fixed incorrect carry operation in 512 addition for Streebog.

	* Fixed -modulus option with openssl(1) dsa subcommand.

	* Fixed PVK format output issue with openssl(1) dsa and rsa subcommand.

2.9.2 - Bug fixes

	* Fixed portable builds with older versions of MacOS,
	  Android targets < API 21, and Solaris 10

	* Fixed SRTP profile advertisement for DTLS servers.

2.9.1 - Stable release

	* Added support for XChaCha20 and XChaCha20-Poly1305.

	* Added support for AES key wrap constructions via the EVP interface.

	* Partial port of the OpenSSL EC_KEY_METHOD API for use by OpenSSH.

	* Added pbkdf2 key derivation support to openssl(1)

	* Removed SHA224 based handshake signatures from consideration for use in a TLS 1.2 handshake.

	* Changed the default digest type of openssl(1) enc to to sha256.

	* Changed the default digest type of openssl(1) dgst to sha256.

	* Changed the default digest type of openssl(1) x509 -fingerprint to sha256.

	* Changed the default digest type of openssl(1) crl -fingerprint to sha256.

	* Improved Windows, Android, and ARM compatibility, including assembly
	  optimizations on Mingw-w64 targets.

2.9.0 - Development release

	* Added the SM4 block cipher from the Chinese standard GB/T 32907-2016.

	* Fixed warnings about clock_gettime on Windows Visual Studio builds.

	* Fixed CMake builds on systems where getpagesize is defined as an
	  inline function.

	* CRYPTO_LOCK is now automatically initialized, with the legacy
	  callbacks stubbed for compatibility.

	* Added the SM3 hash function from the Chinese standard GB/T 32905-2016.

	* Added more OPENSSL_NO_* macros for compatibility with OpenSSL.

	* Added extensive interoperability tests between LibreSSL and OpenSSL
	  1.0 and 1.1.

	* Added additional Wycheproof tests and related bug fixes.

	* Simplified sigalgs option processing and handshake signing algorithm

	* Added the ability to use the RSA PSS algorithm for handshake
	  signatures.

	* Added bn_rand_interval() and use it in code needing ranges of random
	  bn values.

	* Added functionality to derive early, handshake, and application
	  secrets as per RFC8446.

	* Added handshake state machine from RFC8446.

	* Removed some ASN.1 related code from libcrypto that had not been used
	  since around 2000.

	* Unexported internal symbols and internalized more record layer structs.

	* Added support for assembly optimizations on 32-bit ARM ELF targets.

	* Improved protection against timing side channels in ECDSA signature
	  generation.

	* Coordinate blinding was added to some elliptic curves. This is the
	  last bit of the work by Brumley et al. to protect against the
	  Portsmash vulnerability.

	* Ensure transcript handshake is always freed with TLS 1.2.

2.8.2 - Stable release

	* Added Wycheproof support for ECDH and ECDSA Web Crypto test vectors,
	  along with test harness fixes.

	* Fixed memory leak in nc(1)

2.8.1 - Test and compatibility improvements

	* Added Wycheproof support for ECDH, RSASSA-PSS, AES-GCM,
	  AES-CMAC, AES-CCM, AES-CBC-PKCS5, DSA, ChaCha20-Poly1305, ECDSA, and
	  X25519 test vectors. Applied appropriate fixes for errors uncovered
	  by tests.

	* Simplified key exchange signature generation and verification.

	* Fixed a one-byte buffer overrun in callers of EVP_read_pw_string

	* Converted more code paths to use CBB/CBS. All handshake messages are
	  now created by CBB.

	* Fixed various memory leaks found by Coverity.

	* Simplified session ticket parsing and handling, inspired by
	  BoringSSL.

	* Modified signature of CRYPTO_mem_leaks_* to return -1. This function
	  is a no-op in LibreSSL, so this function returns an error to not
	  indicate the (non-)existence of memory leaks.

	* SSL_copy_session_id, PEM_Sign, EVP_EncodeUpdate, BIO_set_cipher,
	  X509_OBJECT_up_ref_count now return an int for error handling,
	  matching OpenSSL.

	* Converted a number of #defines into proper functions, matching
	  OpenSSL's ABI.

	* Added X509_get0_serialNumber from OpenSSL.

	* Removed EVP_PKEY2PKCS8_broken and PKCS8_set_broken, while adding
	  PKCS8_pkey_add1_attr_by_NID and PKCS8_pkey_get0_attrs, matching
	  OpenSSL.

	* Removed broken pkcs8 formats from openssl(1).

	* Converted more functions in public API to use const arguments.

	* Stopped handing AES-GCM in ssl_cipher_get_evp, since they use the
	  EVP_AEAD interface.

	* Stopped using composite EVP_CIPHER AEADs.

	* Added timing-safe compares for checking results of signature
	  verification. There are no known attacks, this is just inexpensive
	  prudence.

	* Correctly clear the current cipher state, when changing cipher state.
	  This fixed an issue where renegotiation of cipher suites would fail
	  when switched from AEAD to non-AEAD or vice-versa.
	  Issue reported by Bernard Spil.

	* Added more cipher tests to appstest.sh, including all TLSv1.2
	  ciphers.

	* Added RSA_meth_get_finish() RSA_meth_set1_name() from OpenSSL.

	* Added new EVP_CIPHER_CTX_(get|set)_iv() API that allows the IV to be
	  retrieved and set with appropriate validation.

2.8.0 - Bug fixes, security, and compatibility improvements

	* Extensive documentation updates and additional API history.

	* Fixed a pair of 20+ year-old bugs in X509_NAME_add_entry

	* Tighten up checks for various X509_VERIFY_PARAM functions,
	  'poisoning' parameters so that an unverified certificate cannot be
	  used if it fails verification.

	* Fixed a potential memory leak on failure in ASN1_item_digest

	* Fixed a potential memory alignment crash in asn1_item_combine_free

	* Removed unused SSL3_FLAGS_DELAY_CLIENT_FINISHED and
	  SSL3_FLAGS_POP_BUFFER flags in write path, simplifying IO paths.

	* Removed SSL_OP_TLS_ROLLBACK_BUG buggy client workarounds.

	* Made ENGINE_finish and ENGINE_free succeed on NULL and simplify callers
	  and matching OpenSSL behavior, rewrote ENGINE_* documentation.

	* Added const annotations to many existing APIs from OpenSSL, making
	  interoperability easier for downstream applications.

	* Fixed small timing side-channels in ecdsa_sign_setup and
	  dsa_sign_setup.

	* Documented security pitfalls with BN_FLG_CONSTTIME and constant-time
	  operation of BN_* functions.

	* Updated BN_clear to use explicit_bzero.

	* Added a missing bounds check in c2i_ASN1_BIT_STRING.

	* More CBS conversions, including simplifications to RSA key exchange,
	  and converted code to use dedicated buffers for secrets.

	* Removed three remaining single DES cipher suites.

	* Fixed a potential leak/incorrect return value in DSA signature
	  generation.

	* Added a blinding value when generating DSA and ECDSA signatures, in
	  order to reduce the possibility of a side-channel attack leaking the
	  private key.

	* Added ECC constant time scalar multiplication support.
	  From Billy Brumley and his team at Tampere University of Technology.

	* Revised the implementation of RSASSA-PKCS1-v1_5 to match the
	  specification in RFC 8017. Based on an OpenSSL commit by David
	  Benjamin.

	* Cleaned up BN_* implementations following changes made in OpenSSL by
	  Davide Galassi and others.

2.7.4 - Security fixes

	* Avoid a timing side-channel leak when generating DSA and ECDSA
	  signatures. This is caused by an attempt to do fast modular
	  arithmetic, which introduces branches that leak information
	  regarding secret values. Issue identified and reported by Keegan
	  Ryan of NCC Group.

	* Reject excessively large primes in DH key generation. Problem
	  reported by Guido Vranken to OpenSSL
	  (https://github.com/openssl/openssl/pull/6457) and based on his
	  diff.

2.7.3 - Bug fixes

	* Removed incorrect NULL checks in DH_set0_key(). Reported by Ondrej
	  Sury

	* Fixed an issue normalizing CPU architecture in the configure script,
	  which disabled assembly optimizations on platforms that get detected
	  as 'amd64', opposed to 'x86_64'

	* Limited tls_config_clear_keys() to only clear private keys.
	  This was inadvertently clearing the keypair, which includes the OCSP
	  staple and pubkey hash - if an application called tls_configure()
	  followed by tls_config_clear_keys(), this would prevent OCSP staples
	  from working.

2.7.2 - Stable release

	* Updated and added extensive new HISTORY sections to API manuals.

	* Added support for shared library builds with CMake on all supported
	  platforms. Note that some of the CMake options have changed, consult
	  the README for details.

2.7.1 - Bug fixes

	* Fixed a bug in int_x509_param_set_hosts, calling strlen() if name
	  length provided is 0 to match the OpenSSL behaviour. Issue noticed
	  by Christian Heimes <christian@python.org>.

	* Fixed builds macOS 10.11 and older.

2.7.0 - Bug fixes and improvements

	* Added support for many OpenSSL 1.0.2 and 1.1 APIs, based on
	  observations of real-world usage in applications. These are
	  implemented in parallel with existing OpenSSL 1.0.1 APIs - visibility
	  changes have not been made to existing structs, allowing code written
	  for older OpenSSL APIs to continue working.

	* Extensive corrections, improvements, and additions to the
	  API documentation, including new public APIs from OpenSSL that had
	  no pre-existing documentation.

	* Added support for automatic library initialization in libcrypto,
	  libssl, and libtls. Support for pthread_once or a compatible
	  equivalent is now required of the target operating system. As a
	  side-effect, minimum Windows support is Vista or higher.

	* Converted more packet handling methods to CBB, which improves
	  resiliency when generating TLS messages.

	* Completed TLS extension handling rewrite, improving consistency of
	  checks for malformed and duplicate extensions.

	* Rewrote ASN1_TYPE_{get,set}_octetstring() using templated ASN.1.
	  This removes the last remaining use of the old M_ASN1_* macros
	  (asn1_mac.h) from API that needs to continue to exist.

	* Added support for client-side session resumption in libtls.
	  A libtls client can specify a session file descriptor (a regular
	  file with appropriate ownership and permissions) and libtls will
	  manage reading and writing of session data across TLS handshakes.

	* Improved support for strict alignment on ARMv7 architectures,
	  conditionally enabling assembly in those cases.

	* Fixed a memory leak in libtls when reusing a tls_config.

	* Merged more DTLS support into the regular TLS code path, removing
	  duplicated code.

	* Many improvements to Windows Cmake-based builds and tests,
	  especially when targeting Visual Studio.

2.6.4 - Bug fixes

	* Make tls_config_parse_protocols() work correctly when passed a NULL
	  pointer for a protocol string. Issue found by semarie@, who also
	  provided the diff.

	* Correct TLS extensions handling when no extensions are present.
	  If no TLS extensions are present in a client hello or server hello,
	  omit the entire extensions block, rather than including it with a
	  length of zero. Thanks to Eric Elena <eric at voguemerry dot com> for
	  providing packet captures and testing the fix.

	* Fixed portable builds on older Android systems, and systems with out
	  IPV6_TCLASS support.

2.6.3 - OpenBSD 6.2 Release

	* No core changes from LibreSSL 2.6.2

	* Minor compatibility fixes in portable version.

2.6.2 - Bug fixes

	* Provide a useful error with libtls if there are no OCSP URLs in a
	  peer certificate.

	* Keep track of which keypair is in use by a TLS context, fixing a bug
	  where a TLS server with SNI would only return the OCSP staple for the
	  default keypair. Issue reported by William Graeber and confirmed by
	  Andreas Bartelt.

	* Fixed various issues in the OCSP extension parsing code.
	  The original code incorrectly passes the pointer allocated via
	  CBS_stow() (using malloc()) to a d2i_*() function and then calls
	  free() on the now incremented pointer, most likely resulting in a
	  crash. This issue was reported by Robert Swiecki who found the issue
	  using honggfuzz.

	* If tls_config_parse_protocols() is called with a NULL pointer,
	  return the default protocols instead of crashing - this makes the
	  behaviour more useful and mirrors what we already do in
	  tls_config_set_ciphers() et al.

2.6.1 - Code removal, rewrites

	* Added a "-T tlscompat" option to nc(1), which enables the use of all
	  TLS protocols and "compat" ciphers. This allows for TLS connections
	  to TLS servers that are using less than ideal cipher suites, without
	  having to resort to "-T tlsall" which enables all known cipher
	  suites.  Diff from Kyle J. McKay.

	* Added a new TLS extension handling framework, somewhat analogous to
	  BoringSSL, and converted all TLS extensions to use it. Added new TLS
	  extension regression tests.

	* Improved and added many new manpages. Updated *check_private_key
	  manpages with additional cautions regarding their use.

	* Cleaned up the EC key/curve configuration handling.

	* Added tls_config_set_ecdhecurves() to libtls, which allows the names
	  of the eliptical curves that may be used during client and server
	  key exchange to be specified.

	* Converted more code paths to use CBB/CBS.

	* Removed support for DSS/DSA, since we removed the cipher suites a
	  while back.

	* Removed NPN support. NPN was never standardised and the last draft
	  expired in October 2012. ALPN was standardised in July 2014 and has
	  been supported in LibreSSL since December 2014. NPN has also been
	  removed from Chromium in May 2016.

	* Removed SSL_OP_CRYPTOPRO_TLSEXT_BUG workaround for old/broken
	  CryptoPro clients.

	* Removed support for the TLS padding extension, which was added as a
	  workaround for an old bug in F5's TLS termination.

	* Worked around another bug in F5's TLS termination handling of the
	  elliptical curves extension. RFC 4492 only defines elliptic_curves
	  for ClientHello. However, F5 is sending it in ServerHello.  We need
	  to skip over it since our TLS extension parsing code is now more
	  strict. Thanks to Armin Wolfermann and WJ Liu for reporting.

	* Added ability to clamp notafter valies in certificates for systems
	  with 32-bit time_t. This is necessary to conform to RFC 5280
	  4.1.2.5.

	* Implemented the SSL_CTX_set_min_proto_version(3) API.

	* Removed the original (pre-IETF) chacha20-poly1305 cipher suites.

	* Reclassified ECDHE-RSA-DES-CBC3-SHA from HIGH to MEDIUM.

2.6.0 - New APIs, bug fixes and improvements

	* Added support for providing CRLs to libtls. Once a CRL is provided we
	  enable CRL checking for the full certificate chain. Based on a diff
	  from Jack Burton

	* Allow non-compliant clients using IP literal addresses with SNI
	  to connect to a server using libtls.

	* Avoid a potential NULL pointer dereference in d2i_ECPrivateKey().
	  Reported by Robert Swiecki, who found the issue using honggfuzz.

	* Added definitions for three OIDs used in EV certificates.
	  From Kyle J. McKay

	* Added tls_peer_cert_chain_pem to libtls, useful in private
	  certificate validation callbacks such as those in relayd.

	* Converted explicit clear/free sequences to use freezero(3).

	* Reworked TLS certificate name verification code to more strictly
	  follow RFC 6125.

	* Cleaned up and simplified server key exchange EC point handling.

	* Added tls_keypair_clear_key for clearing key material.

	* Removed inconsistent IPv6 handling from BIO_get_accept_socket,
	  simplified BIO_get_host_ip and BIO_accept.

	* Fixed the openssl(1) ca command so that is generates certificates
	  with RFC 5280-conformant time. Problem noticed by Harald Dunkel.

	* Added ASN1_TIME_set_tm to set an asn1 from a struct tm *

	* Added SSL{,_CTX}_set_{min,max}_proto_version() functions.

	* Added HKDF (HMAC Key Derivation Function) from BoringSSL

	* Provided a tls_unload_file() function that frees the memory returned
	  from a tls_load_file() call, ensuring that it the contents become
	  inaccessible. This is specifically needed on platforms where the
	  library allocators may be different from the application allocator.

	* Perform reference counting for tls_config. This allows
	  tls_config_free() to be called as soon as it has been passed to the
	  final tls_configure() call, simplifying lifetime tracking for the
	  application.

	* Moved internal state of SSL and other structures to be opaque.

	* Dropped cipher suites with DSS authentication.

	* nc(1) improvements, including:
	   nc -W to terminate nc after receiving a number of packets
	   nc -Z for saving the peer certificate and chain in a pem file

2.5.5 - Bug fixes

	* Distinguish between self-issued certificates and self-signed
	  certificates. The certificate verification code has special cases
	  for self-signed certificates and without this change, self-issued
	  certificates (which it seems are common place with
	  openvpn/easyrsa) were also being included in this category.

	* Added getpagesize fallback, needed for Android bionic libc.

2.5.4 - Security Updates

	* Revert a previous change that forced consistency between return
	  value and error code when specifing a certificate verification
	  callback, since this breaks the documented API. When a user supplied
	  callback always returns 1, and later code checks the error code to
	  potentially abort post verification, this will result in incorrect
	  successul certificate verification.

	* Switched Linux getrandom() usage to non-blocking mode, continuing to
	  use fallback mechanims if unsuccessful. This works around a design
	  flaw in Linux getrandom(2) where early boot usage in a library makes
	  it impossible to recover if getrandom(2) is not yet initialized.

	* Fixed a bug caused by the return value being set early to signal
	  successful DTLS cookie validation. This can mask a later failure and
	  result in a positive return value being returned from
	  ssl3_get_client_hello(), when it should return a negative value to
	  propagate the error.

	* Fixed a build error on non-x86/x86_64 systems running Solaris.

2.5.3 - OpenBSD 6.1 Release

	* Documentation updates

	* Improved ocspcheck(1) error handling

2.5.2 - Security features and bugfixes

	* Added the recallocarray(3) memory allocation function, and converted
	  various places in the library to use it, such as CBB and BUF_MEM_grow.
	  recallocarray(3) is similar to reallocarray. Newly allocated memory
	  is cleared similar to calloc(3). Memory that becomes unallocated
	  while shrinking or moving existing allocations is explicitly
	  discarded by unmapping or clearing to 0

	* Added new root CAs from SECOM Trust Systems / Security Communication
	  of Japan.

	* Added EVP interface for MD5+SHA1 hashes.

	* Fixed DTLS client failures when the server sends a certificate
	  request.

	* Correct handling of padding when upgrading an SSLv2 challenge into
	  an SSLv3/TLS connection.

	* Allow protocols and ciphers to be set on a TLS config object in
	  libtls.

	* Improved nc(1) TLS handshake CPU usage and server-side error
	  reporting.

2.5.1 - Bug and security fixes, new features, documentation updates

	* X509_cmp_time() now passes a malformed GeneralizedTime field as an
	  error. Reported by Theofilos Petsios.

	* Detect zero-length encrypted session data early, instead of when
	  malloc(0) fails or the HMAC check fails. Noted independently by
	  jsing@ and Kurt Cancemi.

	* Check for and handle failure of HMAC_{Update,Final} or
	  EVP_DecryptUpdate().

	* Massive update and normalization of manpages, conversion to
	  mandoc format. Many pages were rewritten for clarity and accuracy.
	  Portable doc links are up-to-date with a new conversion tool.

	* Curve25519 Key Exchange support.

	* Support for alternate chains for certificate verification.

	* Code cleanups, CBS conversions, further unification of DTLS/SSL
	  handshake code, further ASN1 macro expansion and removal.

	* Private symbol are now hidden in libssl and libcryto.

	* Friendly certificate verification error messages in libtls, peer
	  verification is now always enabled.

	* Added OCSP stapling support to libtls and netcat.

	* Added ocspcheck utility to validate a certificate against its OCSP
	  responder and save the reply for stapling

	* Enhanced regression tests and error handling for libtls.

	* Added explicit constant and non-constant time BN functions,
	  defaulting to constant time wherever possible.

	* Moved many leaked implementation details in public structs behind
	  opaque pointers.

	* Added ticket support to libtls.

	* Added support for setting the supported EC curves via
	  SSL{_CTX}_set1_groups{_list}() - also provide defines for the previous
	  SSL{_CTX}_set1_curves{_list} names. This also changes the default
	  list of curves to be X25519, P-256 and P-384. All other curves must
	  be manually enabled.

	* Added -groups option to openssl(1) s_client for specifying the curves
	  to be used in a colon-separated list.

	* Merged client/server version negotiation code paths into one,
	  reducing much duplicate code.

	* Removed error function codes from libssl and libcrypto.

	* Fixed an issue where a truncated packet could crash via an OOB read.

	* Added SSL_OP_NO_CLIENT_RENEGOTIATION option that disallows
	  client-initiated renegotiation. This is the default for libtls
	  servers.

	* Avoid a side-channel cache-timing attack that can leak the ECDSA
	  private keys when signing. This is due to BN_mod_inverse() being
	  used without the constant time flag being set. Reported by Cesar
	  Pereida Garcia and Billy Brumley (Tampere University of Technology).
	  The fix was developed by Cesar Pereida Garcia.

	* iOS and MacOS compatibility updates from Simone Basso and Jacob
	  Berkman.


2.5.0 - New APIs, bug fixes and improvements

	* libtls now supports ALPN and SNI

	* libtls adds a new callback interface for integrating custom IO
	  functions. Thanks to Tobias Pape.

	* libtls now handles 4 cipher suite groups:
	    "secure" (TLSv1.2+AEAD+PFS)
	    "compat" (HIGH:!aNULL)
	    "legacy" (HIGH:MEDIUM:!aNULL)
	    "insecure" (ALL:!aNULL:!eNULL)

	    This allows for flexibility and finer grained control, rather than
	    having two extremes (an issue raised by Marko Kreen some time ago).

	* Tightened error handling for tls_config_set_ciphers().

	* libtls now always loads CA, key and certificate files at the time the
	  configuration function is called. This simplifies code and results in
	  a single memory based code path being used to provide data to libssl.

	* Add support for OCSP intermediate certificates.

	* Added functions used by stunnel and exim from BoringSSL - this
	  brings in X509_check_host, X509_check_email, X509_check_ip, and
	  X509_check_ip_asc.

	* Added initial support for iOS, thanks to Jacob Berkman.

	* Improved behavior of arc4random on Windows when using memory leak
	  analysis software.

	* Correctly handle an EOF that occurs prior to the TLS handshake
	  completing. Reported by Vasily Kolobkov, based on a diff from Marko
	  Kreen.

	* Limit the support of the "backward compatible" ssl2 handshake to
	  only be used if TLS 1.0 is enabled.

	* Fix incorrect results in certain cases on 64-bit systems when
	  BN_mod_word() can return incorrect results. BN_mod_word() now can
	  return an error condition. Thanks to Brian Smith.

	* Added constant-time updates to address CVE-2016-0702

	* Fixed undefined behavior in BN_GF2m_mod_arr()

	* Removed unused Cryptographic Message Support (CMS)

	* More conversions of long long idioms to time_t

	* Improved compatibility by avoiding printing NULL strings with
	  printf.

	* Reverted change that cleans up the EVP cipher context in
	  EVP_EncryptFinal() and EVP_DecryptFinal(). Some software relies on the
	  previous behaviour.

	* Avoid unbounded memory growth in libssl, which can be triggered by a
	  TLS client repeatedly renegotiating and sending OCSP Status Request
	  TLS extensions.

	* Avoid falling back to a weak digest for (EC)DH when using SNI with
	  libssl.

2.4.2 - Bug fixes and improvements

	* Fixed loading default certificate locations with openssl s_client.

	* Ensured OCSP only uses and compares GENERALIZEDTIME values as per
	  RFC6960. Also added fixes for OCSP to work with intermediate
	  certificates provided in responses.

	* Improved behavior of arc4random on Windows to not appear to leak
	  memory in debug tools, reduced privileges of allocated memory.

	* Fixed incorrect results from BN_mod_word() when the modulus is too
	  large, thanks to Brian Smith from BoringSSL.

	* Correctly handle an EOF prior to completing the TLS handshake in
	  libtls.

	* Improved libtls ceritificate loading and cipher string validation.

	* Updated libtls cipher group suites into four categories:
	    "secure"   (TLSv1.2+AEAD+PFS)
	    "compat"   (HIGH:!aNULL)
	    "legacy"   (HIGH:MEDIUM:!aNULL)
	    "insecure" (ALL:!aNULL:!eNULL)
	  This allows for flexibility and finer grained control, rather than
	  having two extremes.

	* Limited support for 'backward compatible' SSLv2 handshake packets to
	  when TLS 1.0 is enabled, providing more restricted compatibility
	  with TLS 1.0 clients.

	* openssl(1) and other documentation improvements.

	* Removed flags for disabling constant-time operations.
	  This removes support for DSA_FLAG_NO_EXP_CONSTTIME,
	  DH_FLAG_NO_EXP_CONSTTIME, and RSA_FLAG_NO_CONSTTIME flags, making
	  all of these operations unconditionally constant-time.


2.4.1 - Security fix

	* Correct a problem that prevents the DSA signing algorithm from
	  running in constant time even if the flag BN_FLG_CONSTTIME is set.
	  This issue was reported by Cesar Pereida (Aalto University), Billy
	  Brumley (Tampere University of Technology), and Yuval Yarom (The
	  University of Adelaide and NICTA). The fix was developed by Cesar
	  Pereida.

2.4.0 - Build improvements, new features

	* Many improvements to the CMake build infrastructure, including
	  Solaris, mingw-w64, Cygwin, and HP-UX support. Thanks to Kinichiro
	  Inoguchi for this work.

	* Added missing error handling around bn_wexpand() calls.

	* Added explicit_bzero calls for freed ASN.1 objects.

	* Fixed X509_*set_object functions to return 0 on allocation failure.

	* Implemented the IETF ChaCha20-Poly1305 cipher suites.

	* Changed default EVP_aead_chacha20_poly1305() implementation to the
	  IETF version, which is now the default.

	* Fixed password prompts from openssl(1) to properly handle ^C.

	* Reworked error handling in libtls so that configuration errors are
	  visible.

	* Deprecated internal use of EVP_[Cipher|Encrypt|Decrypt]_Final.

	* Manpage fixes and updates

2.3.5 - Reliability fix

	* Fixed an error in libcrypto when parsing some ASN.1 elements > 16k.

2.3.4 - Security Update

	* Fix multiple vulnerabilities in libcrypto relating to ASN.1 and encoding.
	From OpenSSL.

	* Minor build fixes

2.3.3 - OpenBSD 5.9 release branch tagged

	* Reworked build scripts to better sync with OpenNTPD-portable

	* Fixed broken manpage links

	* Fixed an nginx compatibility issue by adding an 'install_sw' make alias

	* Fixed HP-UX builds

	* Changed the default configuration directory to c:\LibreSSL\ssl on Windows
	  binary builds

	* cert.pem has been reorganized and synced with Mozilla's certificate store

2.3.2 - Compatibility and Reliability fixes

	* Changed format of LIBRESSL_VERSION_NUMBER to match that of
	  OPENSSL_VERSION_NUMBER, see:
	  https://wiki.openssl.org/index.php/Manual:OPENSSL_VERSION_NUMBER(3)

	* Added EVP_aead_chacha20_poly1305_ietf() which matches the AEAD
	  construction introduced in RFC 7539, which is different than that
	  already used in TLS with EVP_aead_chacha20_poly1305()

	* Avoid a potential undefined C99+ behavior due to shift overflow in
	  AES_decrypt, reported by Pascal Cuoq <cuoq at trust-in-soft.com>

	* More man pages converted from pod to mdoc format

	* Added COMODO RSA Certification Authority and QuoVadis
	  root certificates to cert.pem

	* Removed Remove "C=US, O=VeriSign, Inc., OU=Class 3 Public Primary Certification
	  Authority" (serial 3c:91:31:cb:1f:f6:d0:1b:0e:9a:b8:d0:44:bf:12:be) root
	  certificate from cert.pem

	* Added support for building nc(1) on Solaris

	* Fixed GCC 5.x+ preprocessor checks, reported by Ruslan Babayev

	* Improved console handling with openssl(1) on Windows

	* Ensure the network stack is enabled on Windows when running
	  tls_init()

	* Fixed incorrect TLS certificate loading by nc(1)

	* Added support for Solaris 11.3's getentropy(2) system call

	* Enabled support for using NetBSD 7.0's arc4random(3) implementation

	* Deprecated the SSL_OP_SINGLE_DH_USE flag by disabling its effect

	* Fixes from OpenSSL 1.0.1q
	 - CVE-2015-3194 - NULL pointer dereference in client side certificate
	                   validation.
	 - CVE-2015-3195 - Memory leak in PKCS7 - not reachable from TLS/SSL

	* The following OpenSSL CVEs did not apply to LibreSSL
	 - CVE-2015-3193 - Carry propagating bug in the x86_64 Montgomery
	                   squaring procedure.
	 - CVE-2015-3196 - Double free race condition of the identify hint
	                   data.

	 See https://marc.info/?l=openbsd-announce&m=144925068504102

2.3.1 - ASN.1 and time handling cleanups

	* ASN.1 cleanups and RFC5280 compliance fixes.

	* Time representations switched from 'unsigned long' to 'time_t'. LibreSSL
	  now checks if the host OS supports 64-bit time_t.

	* Fixed a leak in SSL_new in the error path.

	* Support always extracting the peer cipher and version with libtls.

	* Added ability to check certificate validity times with libtls,
	  tls_peer_cert_notbefore and tls_peer_cert_notafter.

	* Changed tls_connect_servername to use the first address that resolves with
	  getaddrinfo().

	* Remove broken conditional EVP_CHECK_DES_KEY code (non-functional since
	  initial commit in 2004).

	* Fixed a memory leak and out-of-bounds access in OBJ_obj2txt, reported
	  by Qualys Security.

	* Fixed an up-to 7 byte overflow in RC4 when len is not a multiple of
	  sizeof(RC4_CHUNK), reported by Pascal Cuoq <cuoq at trust-in-soft.com>.

	* Reject too small bits value in BN_generate_prime_ex(), so that it does
	  not risk becoming negative in probable_prime_dh_safe(), reported by
		Franck Denis.

	* Enable nc(1) builds on more platforms.

2.3.0 - SSLv3 removed, libtls API changes, portability improvements

	* SSLv3 is now permanently removed from the tree.

	* The libtls API is changed from the 2.2.x series.

	  The read/write functions work correctly with external event
	  libraries.  See the tls_init man page for examples of using libtls
	  correctly in asynchronous mode.

	  Client-side verification is now supported, with the client supplying
	  the certificate to the server.

	  Also, when using tls_connect_fds, tls_connect_socket or
	  tls_accept_fds, libtls no longer implicitly closes the passed in
	  sockets. The caller is responsible for closing them in this case.

	* When loading a DSA key from an raw (without DH parameters) ASN.1
	  serialization, perform some consistency checks on its `p' and `q'
	  values, and return an error if the checks failed.

	  Thanks for Georgi Guninski (guninski at guninski dot com) for
	  mentioning the possibility of a weak (non prime) q value and
	  providing a test case.

	  See
	  https://cpunks.org/pipermail/cypherpunks/2015-September/009007.html
	  for a longer discussion.

	* Fixed a bug in ECDH_compute_key that can lead to silent truncation
	  of the result key without error. A coding error could cause software
	  to use much shorter keys than intended.

	* Removed support for DTLS_BAD_VER. Pre-DTLSv1 implementations are no
	  longer supported.

	* The engine command and parameters are removed from the openssl(1).
	  Previous releases removed dynamic and builtin engine support
	  already.

	* SHA-0 is removed, which was withdrawn shortly after publication 20
	  years ago.

	* Added Certplus CA root certificate to the default cert.pem file.

	* New interface OPENSSL_cpu_caps is provided that does not allow
	  software to inadvertently modify cpu capability flags.
	  OPENSSL_ia32cap and OPENSSL_ia32cap_loc are removed.

	* The out_len argument of AEAD changed from ssize_t to size_t.

	* Deduplicated DTLS code, sharing bugfixes and improvements with
	  TLS.

	* Converted 'nc' to use libtls for client and server operations; it is
	  included in the libressl-portable distribution as an example of how
	  to use the library.

2.2.3 - Bug fixes, build enhancements

	* LibreSSL 2.2.2 incorrectly handles ClientHello messages that do not
	  include TLS extensions, resulting in such handshakes being aborted.
	  This release corrects the handling of such messages. Thanks to
	  Ligushka from github for reporting the issue.

	* Added install target for cmake builds. Thanks to TheNietsnie from
	  github.

	* Updated pkgconfig files to correctly report the release version
	  number, not the individual library ABI version numbers. Thanks to
	  Jan Engelhardt for reporting the issue.

2.2.2 - More TLS parser rework, bug fixes, expanded portable build support

	* Switched 'openssl dhparam' default from 512 to 2048 bits

	* Reworked openssl(1) option handling

	* More CRYPTO ByteString (CBC) packet parsing conversions

	* Fixed 'openssl pkeyutl -verify' to exit with a 0 on success

	* Fixed dozens of Coverity issues including dead code, memory leaks,
	  logic errors and more.

	* Ensure that openssl(1) restores terminal echo state after reading a
	  password.

	* Incorporated fix for OpenSSL Issue #3683

	* LibreSSL version define LIBRESSL_VERSION_NUMBER will now be bumped
	  for each portable release.

	* Removed workarounds for TLS client padding bugs.

	* No longer disable ECDHE-ECDSA on OS X

	* Removed SSLv3 support from openssl(1)

	* Removed IE 6 SSLv3 workarounds.

	* Modified tls_write in libtls to allow partial writes, clarified with
	  examples in the documentation.

	* Removed RSAX engine

	* Tested SSLv3 removal with the OpenBSD ports tree and found several
	  applications that were not ready to build without SSLv3 yet. For
	  now, building a program that intentionally uses SSLv3 will result in
	  a linker warning.

	* Added TLS_method, TLS_client_method and TLS_server_method as a
	  replacement for the SSLv23_*method calls.

	* Added initial cmake build support, including support for building with
	  Visual Studio, currently tested with Visual Studio 2013 Community
	  Edition.

	* --with-enginesdir is removed as a configuration parameter

	* Default cert.pem, openssl.cnf, and x509v3.cnf files are now
	  installed under $sysconfdir/ssl or the directory specified by
	  --with-openssldir. Previous versions of LibreSSL left these empty.

2.2.1 - Build fixes, feature added, features removed

	* Assorted build fixes for musl, HP-UX, Mingw, Solaris.

	* Initial support for Windows Embedded 2009, Server 2003, XP

	* Protocol parsing conversions to BoringSSL's CRYPTO ByteString (CBS) API

	* Added EC_curve_nid2nist and EC_curve_nist2nid from OpenSSL

	* Removed Dynamic Engine support

	* Removed unused and obsolete MDC-2DES cipher

	* Removed workarounds for obsolete SSL implementations

2.2.0 - Build cleanups and new OS support, Security Updates

	* AIX Support - thanks to Michael Felt

	* Cygwin Support - thanks to Corinna Vinschen

	* Refactored build macros, support packaging libtls independently.
	  There are more pieces required to support building and using OpenSSL
	  with libtls, but this is an initial start at providing an
	  independent package for people to start hacking on.

	* Removal of OPENSSL_issetugid and all library getenv calls.
	  Applications can and should no longer rely on environment variables
	  for changing library behavior. OPENSSL_CONF/SSLEAY_CONF is still
	  supported with the openssl(1) command.

	* libtls API and documentation additions

	* Various bug fixes and simplifications to libssl and libcrypto

	* Fixes for the following issues are integrated into LibreSSL 2.2.0:
	 - CVE-2015-1788 - Malformed ECParameters causes infinite loop
	 - CVE-2015-1789 - Exploitable out-of-bounds read in X509_cmp_time
	 - CVE-2015-1792 - CMS verify infinite loop with unknown hash function

	* The following CVEs did not apply to LibreSSL or were fixed in
	  earlier releases:
	 - CVE-2015-4000 - DHE man-in-the-middle protection (Logjam)
	 - CVE-2015-1790 - PKCS7 crash with missing EnvelopedContent
	 - CVE-2014-8176 - Invalid free in DTLS

	* Fixes for the following CVEs are still in review for LibreSSL
	 - CVE-2015-1791 - Race condition handling NewSessionTicket

2.1.6 - Security update

	* Fixes for the following issues are integrated into LibreSSL 2.1.6:
	  - CVE-2015-0209 - Use After Free following d2i_ECPrivatekey error
	  - CVE-2015-0286 - Segmentation fault in ASN1_TYPE_cmp
	  - CVE-2015-0287 - ASN.1 structure reuse memory corruption
	  - CVE-2015-0288 - X509_to_X509_REQ NULL pointer deref
	  - CVE-2015-0289 - PKCS7 NULL pointer dereferences

	* The fix for CVE-2015-0207 - Segmentation fault in DTLSv1_listen
	  is integrated for safety, but LibreSSL is not vulnerable.

	* Libtls is now built by default. The --enable-libtls
	  configuration option is no longer required.
	  The libtls API is now stable for the 2.1.x series.

2.1.5 - Bug fixes and a security update
	* Fix incorrect comparison function in openssl(1) certhash command.
	  Thanks to Christian Neukirchen / Void Linux.

	* Windows port improvements and bug fixes.
	  - Removed a dependency on libgcc in 32-bit dynamic libraries.
	  - Correct a hang in openssl(1) reading from stdin on an connection.
	  - Initialize winsock in openssl(1) earlier, allow 'openssl ocsp' and
	    any other network-related commands to function properly.

	* Reject all server DH keys smaller than 1024 bits.

2.1.4 - Security and feature updates
	* Improvements to libtls:
	  - a new API for loading CA chains directly from memory instead of a
	    file, allowing verification with privilege separation in a chroot
	    without direct access to CA certificate files.

	  - Ciphers default to TLSv1.2 with AEAD and PFS.

	  - Improved error handling and message generation

	  - New APIs and improved documentation

	* Added X509_STORE_load_mem API for loading certificates from memory.
	  This facilitates accessing certificates from a chrooted environment.

	* New AEAD "MAC alias" allows configuring TLSv1.2 AEAD ciphers by
	  using 'TLSv1.2+AEAD' as the cipher selection string.

	* Dead and disabled code removal including MD5, Netscape workarounds,
	  non-POSIX IO, SCTP, RFC 3779 support, many #if 0 sections, and more.

	* ASN1 macro maze expanded to aid reading and searching the code.

	* NULL pointer asserts removed in favor of letting the OS/signal
	  handler catch them.

	* Refactored argument handling in openssl(1) for consistency and
	  maintainability.

	* New openssl(1) command 'certhash' replaces the c_rehash script.

	* Support for building with OPENSSL_NO_DEPRECATED

	* Server-side support for TLS_FALLBACK_SCSV for compatibility with
	  various auditor and vulnerability scanners.

	* Dozens of issues found with the Coverity scanner fixed.

	* Security Updates:

	  - Fix a minor information leak that was introduced in t1_lib.c
	    r1.71, whereby an additional 28 bytes of .rodata (or .data) is
	    provided to the network. In most cases this is a non-issue since
	    the memory content is already public. Issue found and reported by
	    Felix Groebert of the Google Security Team.

	  - Fixes for the following low-severity issues were integrated into
	    LibreSSL from OpenSSL 1.0.1k:

	     CVE-2015-0205 - DH client certificates accepted without
	                     verification
	     CVE-2014-3570 - Bignum squaring may produce incorrect results
	     CVE-2014-8275 - Certificate fingerprints can be modified
	     CVE-2014-3572 - ECDHE silently downgrades to ECDH [Client]
	     Reported by Karthikeyan Bhargavan of the PROSECCO team at INRIA.

	    The following CVEs were fixed in earlier LibreSSL releases:
	     CVE-2015-0206 - Memory leak handling repeated DLTS records
	     CVE-2014-3510 - Flaw handling DTLS anonymous EC(DH) ciphersuites.

	    The following CVEs did not apply to LibreSSL:
	     CVE-2014-3571 - DTLS segmentation fault in dtls1_get_record
	     CVE-2014-3569 - no-ssl3 configuration sets method to NULL
	     CVE-2015-0204 - RSA silently downgrades to EXPORT_RSA

2.1.3 - Security update and OS support improvements
	* Fixed various memory leaks in DTLS, including fixes for
	  CVE-2015-0206.

	* Added Application-Layer Protocol Negotiation (ALPN) support.

	* Removed GOST R 34.10-94 signature authentication.

	* Removed nonfunctional Netscape browser-hang workaround code.

	* Simplified and refactored SSL/DTLS handshake code.

	* Added SHA256 Camellia cipher suites for TLS 1.2 from RFC 5932.

	* Hide timing info about padding errors during handshakes.

	* Improved libtls support for non-blocking sockets, added randomized
	  session ID contexts. Work is ongoing with this library - feedback
	  and potential use-cases are welcome.

	* Support building Windows DLLs.
	  Thanks to Jan Engelhard.

	* Packaged config wrapper for better compatibility with OpenSSL-based
	  build systems.
	  Thanks to @technion from github

	* Ensure the stack is marked non-executable for assembly sections.
	  Thanks to Anthony G. Bastile.

	* Enable extra compiler hardening flags by default, where applicable.
	  The default set of hardening features can vary by OS to OS, so
	  feedback is welcome on this. To disable the default hardening flags,
	  specify '--disable-hardening' during configure.
	  Thanks to Jim Barlow

	* Initial HP-UX support, tested with HP-UX 11.31 ia64
	  Thanks to Kinichiro Inoguchi

	* Initial NetBSD support, tested with NetBSD 6.1.5 x86_64
	  Imported from OpenNTPD, thanks to @gitisihara from github

2.1.2 - Many new features and improvements
	* Added reworked GOST cipher suite support
	   thanks to Dmitry Eremin-Solenikov

	* Enabled Camellia ciphers due to improved patent situation

	* Use builtin arc4random implementation on OS X and FreeBSD
	   this addresses some deficiencies in the native implementations of
	   these operating systems, see commit logs for more information

	* Added initial Windows mingw-w64 support (32 and 64-bit)
	   thanks to Song Dongsheng and others for code and feedback

	* Enabled assembly optimizations on x86_64 CPUs
	   supports Linux, *BSD, Solaris and OS X operating systems
	   thanks to Wouter Clarie for the initial implementation

	* Added no_ssl3/no_tls1_1/no_tls1_2 options to openssl(1)

	* Improved build infrastructure, 'make distcheck' now passes
	   this simplifies and speeds developer efficiency
	   thanks to Dmitry Eremin-Solenikov and Wouter Clarie

	* Allow conditional building of the libtls library
	   expect the API and ABI of the library to change
	   feedback is welcome

	* Fixes for more memory leaks, cleanups, etc.

2.1.1 - Security update
	* Address POODLE attack by disabling SSLv3 by default

	* Fix Eliptical Curve cipher selection bug
	  (https://github.com/libressl-portable/portable/issues/35)

2.1.0 - First release from the OpenBSD 5.7 tree
	* Added support for automatic ephemeral EC keys

	* Fixes for many memory leaks and overflows in error handlers

	* The TLS padding extension (that works around bugs in F5 terminators) is
	  off by default

	* support for getrandom(2) on Linux 3.17

	* the NO_ASM macro is no longer being set, providing the first bits toward
	  enabling other assembly offloads.

2.0.5 - Fixes for CVEs from OpenSSL 1.0.1i
	* CVE-2014-3506
	* CVE-2014-3507
	* CVE-2014-3508 (partially vulnerable)he
	* CVE-2014-3509
	* CVE-2014-3510
	* CVE-2014-3511
	* Synced LibreSSL Portable with the release version of OpenBSD 5.6

2.0.4 - Portability fixes, deleted unused SRP code

2.0.3 - Portability fixes, improvements to fork detection

2.0.2 - Address arc4random fork PID wraparound issues with pthread_atfork

2.0.1 - Portability fixes:
	* Removed -Werror and and other non-portable compiler flags

	* Allow setting OPENSSLDIR and ENGINSDIR

2.0.0 - First release from the OpenBSD 5.6 tree
	* Removal of many obsolete features and coding conventions from the OpenSSL
	  1.0.1h source