+ Fixed a vulnerability in the TLS ciphersuites based on use of CBC and SHA-384 in DTLS/TLS 1.0 to 1.2, that allowed an active network attacker to partially recover the plaintext of messages under certains conditions by exploiting timing side-channels.
+ Fixed a vulnerability in TLS ciphersuites based on CBC, in DTLS/TLS 1.0 to 1.2, that allowed a local attacker, with the ability to execute code on the local machine as well as to manipulate network packets, to partially recover the plaintext of messages under certain conditions by using a cache attack targetting an internal MD/SHA buffer.
+ Added a counter-measure against a vulnerability in TLS ciphersuites based on CBC, in DTLS/TLS 1.0 to 1.2, that allowed a local attacker with the ability to execute code on the local machine as well as manipulate network packets, to partially recover the plaintext of messages certain conditions (see previous entry) by using a cache attack targeting the SSL input record buffer.
* Features
+ Added new cryptographic primitives, the stream cipher Chacha20, one-time authenticator Poly1305 and AEAD construct Chacha20-Poly1305, as defined in RFC 7539. Contributed by Daniel King.
+ Added support for the CHACHA20-POLY1305 ciphersuites from RFC 7905.
+ Made the receive and transmit buffers independently configurable in size, for situations where the outgoing buffer can be fixed at a smaller size than the incoming buffer
+ Added support for the AES based key wrapping modes defined by NIST SP 800-38F algorithms KW and KWP and by RFC's 3394 and 5649.
+ Added platform support for the Haiku OS.
* Bugfix
+ Fixed the key_app_writer example which was creating an invalid ASN.1 tag by writing an additional leading zero byte. Found by Aryeh R. #1257.
+ Fixed a C++ compilation error, caused by a variable named new. Found and fixed by Hirotaka Niisato. #1783.
+ Fixed the "no symbols" warning issued by ranlib when building on Mac OS X. Fix contributed by tabascoeye.
+ Clarified documentation for mbedtls_ssl_write() to include 0 as a valid return value. Found by @davidwu2000. #839.
+ Fixed a memory leak in mbedtls_x509_csr_parse(). Found and fixed by catenacyber, Philippe Antoine. #1623.
+ Added length checks to some TLS parsing functions. Found and fixed by Philippe Antoine from Catena cyber. #1663.
+ Remove unused headers included in x509.c. Found by Chris Hanson and fixed by Brendan Shanks. #992.
+ Fixed compilation error when MBEDTLS_ARC4_C is disabled and MBEDTLS_CIPHER_NULL_CIPHER is enabled. Found by TrinityTonic in #1719.
+ Fixed the inline assembly for the MPI multiply helper function for i386 and i386 with SSE2. Found by László Langó. #1550.
+ Fixed the namespacing in header files. Remove the mbedtls namespacing in the #include in the header files. #857.
+ Fixed a compiler warning of 'use before initialisation' in mbedtls_pk_parse_key(). Found by Martin Boye Petersen and fixed by Dawid Drozd.#1098.
+ Fixed decryption of zero length messages (which contain all padding) when a CBC based ciphersuite was used together with Encrypt-then-MAC.
+ Fixed the ssl_client2 example to send application data with 0-length content when the request_size argument is set to 0 as stated in the documentation. #1833.
+ Corrected the documentation for mbedtls_ssl_get_session(). This API has deep copy of the session, and the peer certificate is not lost. #926.
+ Fixed issues when building to the C99 standard, using -std=c99. Fixed by Nick Wilson.
* Changes
+ Fails when receiving a TLS alert message with an invalid length, or invalid zero-length messages when using TLS 1.2. Contributed by Espressif Systems.
+ Changed the default behaviour of mbedtls_hkdf_extract() to return an error when calling with a NULL salt and non-zero salt length. Contributed by Brian J Murray
+ Change the shebang line in Perl scripts to look up perl in the PATH. Contributed by fbrosson.
+ Allow overriding the time on Windows via the platform-time abstraction. Fixed by Nick Wilson.
+ Use gmtime_r/gmtime_s for thread-safety. Fixed by Nick Wilson.
+ Added support for the XTS block cipher mode with AES (AES-XTS). Contributed by Aorimn in pull request #414.
+ Implemented the HMAC-based extract-and-expand key derivation function (HKDF) per RFC 5869. Contributed by Thomas Fossati.
+ For TLS servers, added support for offloading private key operations to an external cryptoprocessor. Private key operations can be asynchronous to allow non-blocking operation of the TLS server stack.
+ Added support for ARIA cipher (RFC 5794) and associated TLS ciphersuites (RFC 6209). ARIA is disabled by default. To enable, see MBEDTLS_ARIA_C in config.h.
+ Added support for the CCM* block cipher mode as defined in IEEE Std 802.15.4.
+ Added an additional block mode, OFB (Output Feedback) per NIST SP 800-38a, to the AES module and cipher abstraction module.
* API Changes
+ Mbed TLS 2.11.0 maintains source code compatibility with the last minor version, Mbed TLS 2.9.0, but extends the interface with additional capabilities. Mbed TLS 2.11.0 modifies the ABI and increases the SOVERSION.
* Bugfix
+ Fixed the cert_write example to handle certificates signed with elliptic curves as well as RSA. Fixes #777 found by dbedev.
+ Fixed the redefinition of _WIN32_WINNT, to avoid overriding a definition used by user applications. Found and fixed by Fabio Alessandrelli.
+ Fixed compilation warnings with the IAR toolchain on 32-bit platforms. Reported by rahmanih in #683.
+ Fixed an issue with MicroBlaze support in bn_mul.h which was causing the build to fail. Found by zv-io. Fixes #1651.
+ Fixed braces in mbedtls_memory_buffer_alloc_status(). Found by sbranden in #552.
+ Added the macro MBEDTLS_X509_MAX_FILE_PATH_LEN that enables the user to configure the maximum length of a file path that can be buffered when calling mbedtls_x509_crt_parse_path(). Fixes #492.
+ Fixed redundant declaration of mbedtls_ssl_list_ciphersuites. Raised by TrinityTonic in #1359.
- Changes for version 2.9.0:
+ Security
+ Fixed an issue in the X.509 module which could lead to a buffer overread during certificate validation. Additionally, the issue could also lead to unnecessary callback checks being made or to some validation checks to be omitted. The overread could be triggered remotely, while the other issues would require a non DER-compliant certificate to be correctly signed by a trusted CA, or a trusted CA with a non DER-compliant certificate. Found by luocm. Fixes #825.
+ Fixed the buffer length assertion in the ssl_parse_certificate_request() function which could lead to an arbitrary overread of the message buffer. The overreads could be caused by receiving a malformed algorithms section which was too short. In builds with debug output, this overread data was output with the debug data.
+ Fixed a client-side bug in the validation of the server's ciphersuite choice which could potentially lead to the client accepting a ciphersuite it didn't offer or a ciphersuite that could not be used with the TLS or DTLS version chosen by the server. This could lead to corruption of internal data structures for some configurations.
* Features
+ Added an option of MBEDTLS_AES_FEWER_TABLES, to dynamically compute smaller AES tables during runtime, thereby reducing the RAM/ROM footprint by ~6KiB. Suggested and contributed by jkivilin.
+ Added initial support for Curve448 (RFC 7748). So far only mbedtls_ecp_mul() and ECDH primitive functions (mbedtls_ecdh_gen_public(), mbedtls_ecdh_compute_shared()) are supported for now. Contributed by Nicholas Wilson.
* API Changes
+ Mbed TLS 2.9.0 maintains source code and binary compatibility with the last minor version, Mbed TLS 2.8.0, but extends the interface with additional capabilities.
+ Extended the API with the function of mbedtls_net_poll() to allow user applications to wait for a network context to become ready before reading or writing.
+ Added the function mbedtls_ssl_check_pending() to the public API to allow a check for whether more more data is pending to be processed in the internal message buffers. This function is necessary to determine the underlying transport when event-driven IO is used.
* Bugfix
+ Fixed a spurious uninitialized variable warning in cmac.c. Fix independently contributed by Brian J Murray and David Brown.
+ Added missing dependencies in test suites that led to build failures in configurations that omit certain hashes or public-key algorithms. Fixes #1040.
+ Fixed a C89 incompatibility issue in benchmark.c. Contributed by Brendan Shanks. Fixes #1353.
+ Added missing dependencies for MBEDTLS_HAVE_TIME_DATE and MBEDTLS_VERSION_FEATURES in some test suites. Contributed by Deomid Ryabkov. Fixes #1299, #1475.
+ Fixed the Makefile build process for building shared libraries on Mac OS X. Fixed by mnacamura.
+ Fixed parsing of PKCS#8 encoded Elliptic Curve keys. Previously Mbed TLS was unable to parse keys which had only the optional parameters field of the ECPrivateKey structure. Found by Jethro Beekman, fixed in #1379.
+ Added an optimisation to return the plaintext data more quickly on unpadded CBC decryption, as stated in the mbedtls_cipher_update() documentation. Contributed by Andy Leiserson.
+ Fixed the overriding and ignoring of return values when parsing and writing to a file in the pk_sign program. Found by kevlut in #1142.
+ Added restrictions to the usage of the error code MBEDTLS_ERR_SSL_WANT_READ to situations where data needs to be fetched from the underlying transport in order to make progress. Previously, this error code was also occasionally returned when unexpected messages were being discarded, ignoring that further messages could potentially already be pending to be processed in the internal buffers; these cases led to deadlocks when event-driven I/O was used. Found and reported by Hubert Mis in #772.
+ Fixed buffer length assertions in the ssl_parse_certificate_request() function which led to a potential one byte overread of the message buffer.
+ Fixed invalid buffer sizes being passed to zlib during record compression and decompression.
+ Raised the soversion of libmbedcrypto to match the soversion of the maintained 2.7 branch. The soversion was increased in Mbed TLS version 2.7.1 to reflect breaking changes in that release, but the increment was missed in 2.8.0 and later releases outside of the 2.7 branch.
+ Defend against Bellcore glitch attacks by verifying the results of RSA private key operations.
+ Fix implementation of the truncated HMAC extension. The previous implementation allowed an offline 2^80 brute force attack on the HMAC key of a single, uninterrupted connection (with no resumption of the session).
+ Reject CRLs containing unsupported critical extensions. Found by Falko Strenzke and Evangelos Karatsiolis.
+ Fix a buffer overread in ssl_parse_server_key_exchange() that could cause a crash on invalid input.
+ Fix a buffer overread in ssl_parse_server_psk_hint() that could cause a crash on invalid input.
* Features:
+ Enable reading encrypted PEM files produced by software that uses PBKDF2-SHA2, such as OpenSSL 1.1. Submitted by Antonio Quartulli, OpenVPN Inc. Fixes #1339
+ Support public keys encoded in PKCS#1 format. #1122
* New deprecations:
+ Compression and crypto don't mix. We don't recommend using compression and cryptography, and have deprecated support for record compression (configuration option MBEDTLS_ZLIB_SUPPORT).
* Bugfix:
+ Fix mbedtls_x509_crt_profile_suiteb, which used to reject all certificates with flag MBEDTLS_X509_BADCERT_BAD_PK even when the key type was correct. In the context of SSL, this resulted in handshake failure. Reported by daniel in the Mbed TLS forum. #1351
+ Fix setting version TLSv1 as minimal version, even if TLS 1 is not enabled. Set MBEDTLS_SSL_MIN_MAJOR_VERSION and MBEDTLS_SSL_MIN_MINOR_VERSION instead of MBEDTLS_SSL_MAJOR_VERSION_3 and MBEDTLS_SSL_MINOR_VERSION_1. #664
+ Fix compilation error on Mingw32 when _TRUNCATE is defined. Use _TRUNCATE only if __MINGW32__ is not defined. Fix suggested by Thomas Glanzmann and Nick Wilson on issue #355
+ Fix memory allocation corner cases in memory_buffer_alloc.c module. Found by Guido Vranken. #639
+ Don't accept an invalid tag when parsing X.509 subject alternative names in some circumstances.
+ Fix a possible arithmetic overflow in ssl_parse_server_key_exchange() that could cause a key exchange to fail on valid data.
+ Fix a possible arithmetic overflow in ssl_parse_server_psk_hint() that could cause a key exchange to fail on valid data.
+ Fix a 1-byte heap buffer overflow (read-only) during private key parsing. Found through fuzz testing.
* Changes
+ Fix tag lengths and value ranges in the documentation of CCM encryption. Contributed by Mathieu Briand.
+ Fix a typo in a comment in ctr_drbg.c. Contributed by Paul Sokolovsky.
+ Remove support for the library reference configuration for picocoin.
+ MD functions deprecated in 2.7.0 are no longer inline, to provide a migration path for those depending on the library's ABI.
+ Use (void) when defining functions with no parameters. Contributed by Joris Aerts. #678
