*** Description ***

The wolfSSL embedded SSL library (formerly CyaSSL) is a lightweight SSL/TLS
library written in ANSI C and targeted for embedded, RTOS, and
resource-constrained environments - primarily because of its small size, speed,
and feature set.  It is commonly used in standard operating environments as well
because of its royalty-free pricing and excellent cross platform support.
wolfSSL supports industry standards up to the current TLS 1.3 and DTLS 1.2
levels, is up to 20 times smaller than OpenSSL, and offers progressive ciphers
such as ChaCha20, Curve25519, and Blake2b. User benchmarking and feedback
reports dramatically better performance when using wolfSSL over OpenSSL.

wolfSSL is powered by the wolfCrypt library. Two versions of the wolfCrypt
cryptography library have been FIPS 140-2 validated (Certificate #2425 and
certificate #3389). For additional information, visit the wolfCrypt FIPS FAQ
(https://www.wolfssl.com/license/fips/) or contact fips@wolfssl.com

*** Why choose wolfSSL? ***

There are many reasons to choose wolfSSL as your embedded SSL solution. Some of
the top reasons include size (typical footprint sizes range from 20-100 kB),
support for the newest standards (SSL 3.0, TLS 1.0, TLS 1.1, TLS 1.2, TLS 1.3,
DTLS 1.0, and DTLS 1.2), current and progressive cipher support (including
stream ciphers), multi-platform, royalty free, and an OpenSSL compatibility API
to ease porting into existing applications which have previously used the
OpenSSL package. For a complete feature list, see chapter 4 of the wolfSSL
manual. (https://www.wolfssl.com/docs/wolfssl-manual/ch4/)

*** Notes, Please read ***

Note 1)
wolfSSL as of 3.6.6 no longer enables SSLv3 by default.  wolfSSL also no longer
supports static key cipher suites with PSK, RSA, or ECDH. This means if you
plan to use TLS cipher suites you must enable DH (DH is on by default), or
enable ECC (ECC is on by default), or you must enable static key cipher suites
with

    WOLFSSL_STATIC_DH
    WOLFSSL_STATIC_RSA
      or
    WOLFSSL_STATIC_PSK

though static key cipher suites are deprecated and will be removed from future
versions of TLS.  They also lower your security by removing PFS.

When compiling ssl.c, wolfSSL will now issue a compiler error if no cipher
suites are available. You can remove this error by defining
WOLFSSL_ALLOW_NO_SUITES in the event that you desire that, i.e., you're not
using TLS cipher suites.

Note 2)
wolfSSL takes a different approach to certificate verification than OpenSSL
does. The default policy for the client is to verify the server, this means
that if you don't load CAs to verify the server you'll get a connect error,
no signer error to confirm failure (-188).

If you want to mimic OpenSSL behavior of having SSL_connect succeed even if
verifying the server fails and reducing security you can do this by calling:

    wolfSSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, 0);

before calling wolfSSL_new();. Though it's not recommended.

Note 3)
The enum values SHA, SHA256, SHA384, SHA512 are no longer available when
wolfSSL is built with --enable-opensslextra (OPENSSL_EXTRA) or with the macro
NO_OLD_SHA_NAMES. These names get mapped to the OpenSSL API for a single call
hash function. Instead the name WC_SHA, WC_SHA256, WC_SHA384 and WC_SHA512
should be used for the enum name.

*** end Notes ***


# wolfSSL Release 5.5.3 (Nov 2, 2022)

Release 5.5.3 of wolfSSL embedded TLS has the following bug fix:

## Fixes

* Fix for possible buffer zeroization overrun introduced at the end of v5.5.2 release cycle in GitHub pull request 5743 (https://github.com/wolfSSL/wolfssl/pull/5743) and fixed in pull request 5757 (https://github.com/wolfSSL/wolfssl/pull/5757). In the case where a specific memory allocation failed or a hardware fault happened there was the potential for an overrun of 0’s when masking the buffer used for (D)TLS 1.2 and lower operations. (D)TLS 1.3 only and crypto only users are not affected by the issue. This is not related in any way to recent issues reported in OpenSSL.


# wolfSSL Release 5.5.2 (Oct 28, 2022)
Release 5.5.2 of wolfSSL embedded TLS has bug fixes and new features including:

## Vulnerabilities
* [Med] In the case that the WOLFSSL_CALLBACKS macro is set when building wolfSSL, there is a potential heap over read of 5 bytes when handling TLS 1.3 client connections. This heap over read is limited to wolfSSL builds explicitly setting the macro WOLFSSL_CALLBACKS, the feature does not get turned on by any other build options. The macro WOLFSSL_CALLBACKS is intended for debug use only, but if having it enabled in production, users are recommended to disable WOLFSSL_CALLBACKS. Users enabling WOLFSSL_CALLBACKS are recommended to update their version of wolfSSL. Thanks to Lucca Hirschi and Steve Kremer from LORIA, Inria and Max Ammann from Trail of Bits for finding and reporting the bug with the tlspuffin tool developed partly at LORIA and Trail of Bits. CVE 2022-42905

Release 5.5.2 of wolfSSL embedded TLS has bug fixes and new features including:

## New Feature Additions
* Add function wolfSSL_CTX_load_system_CA_certs to load system CA certs into a WOLFSSL_CTX and  --sys-ca-certs option to example client
* Add wolfSSL_set1_host to OpenSSL compatible API
* Added the function sk_X509_shift
* AES x86 ASM for AES-CBC and GCM performance enhancements
* Add assembly for AES for ARM32 without using crypto hardware instructions
* Xilinx Versal port and hardware acceleration tie in
* SP Cortex-M support for ICCARM

## Enhancements
* Add snifftest vcxproj file and documentation
* Nucleus Thread Types supported
* Handle certificates with RSA-PSS signature that have RSAk public keys
* Small stack build improvements
* DTLS 1.3 improvements for Alerts and unit tests
* Add a binary search for CRL
* Improvement of SSL/CTX_set_max_early_data() for client side
* Remove unused ASN1_GENERALIZEDTIME enum value from wolfssl/ssl.h
* Add user_settings.h for Intel/M1 FIPSv2 macOS C++ projects
* Add dtlscid.test to ‘make check’ unit testing
* Generate an assembler-safe user_settings.h in configure.ac and CMakeLists.txt
* ForceZero enabled with USE_FAST_MATH
* Add TLS 1.3 support of ticketNonce sizes bigger than MAX_TICKET_NONCE_SZ
* FIPSv2 builds on win10 adjust for new fastmath default in settings.h
* Add IRQ install for Aruix example

## Fixes
* When looking up the session by ID on the server, check that the protocol version of the SSL and session match on TLS 1.3 or not
* Fix for potential EVP_PKEY_DH memory leak with OPENSSL_EXTRA
* Curve448 32-bit C code: handle corner case
* Fixup builds using WOLFSSL_LOG_PRINTF
* Correct DIST_POINT_NAME type value
* Do not perform IV Wrap test when using cert3389 inlined armasm
* Fix for Linux kernel module and stdio.h
* (D)TLS: send alert on version mismatch
* Fix PKCS#7 SignedData verification when signer cert is not first in SET
* Fix bug with wolfIO_TcpConnect not working with timeout on Windows
* Fix output length bug in SP non-blocking ECC shared secret gen
* Fix build with enable-fastmath and disable-rsa
* Correct wolfSSL_sk_X509_new in OpenSSL compatible API
* Fixes for SP and x86_64 with MSVC
* Fix wrong size using DTLSv1.3 in RestartHandshakeHashWithCookie
* Fix redundant file include with TI RTOS build
* Fix wolfCrypt only build with wincrypt.h
* DTLS 1.2: Reset state when sending HelloVerifyRequest

For additional vulnerability information visit the vulnerability page at:
https://www.wolfssl.com/docs/security-vulnerabilities/

See INSTALL file for build instructions.
More info can be found on-line at: https://wolfssl.com/wolfSSL/Docs.html

*** Resources ***


[wolfSSL Website](https://www.wolfssl.com/)

[wolfSSL Wiki](https://github.com/wolfSSL/wolfssl/wiki)

[FIPS FAQ](https://wolfssl.com/license/fips)

[wolfSSL Documents](https://wolfssl.com/wolfSSL/Docs.html)

[wolfSSL Manual](https://wolfssl.com/wolfSSL/Docs-wolfssl-manual-toc.html)

[wolfSSL API Reference]
(https://wolfssl.com/wolfSSL/Docs-wolfssl-manual-17-wolfssl-api-reference.html)

[wolfCrypt API Reference]
(https://wolfssl.com/wolfSSL/Docs-wolfssl-manual-18-wolfcrypt-api-reference.html)

[TLS 1.3](https://www.wolfssl.com/docs/tls13/)

[wolfSSL Vulnerabilities]
(https://www.wolfssl.com/docs/security-vulnerabilities/)

Additional wolfSSL Examples](https://github.com/wolfssl/wolfssl-examples)
