WolfSSL


wolfSSL is a small, portable, embedded SSL/TLS library targeted for use by embedded systems developers. It is an open source implementation of TLS written in the C programming language. It includes SSL/TLS client libraries and an SSL/TLS server implementation as well as support for multiple APIs, including those defined by SSL and TLS. wolfSSL also includes an OpenSSL compatibility interface with the most commonly used OpenSSL functions.
A predecessor of wolfSSL, yaSSL is a C++ based SSL library for embedded environments and real time operating systems with constrained resources.

Platforms

wolfSSL is currently available for Win32/64, Linux, macOS, Solaris, Threadx, VxWorks, FreeBSD, NetBSD, OpenBSD, embedded Linux, Yocto Project, OpenEmbedded, WinCE, Haiku, OpenWrt, iPhone, Android, Nintendo Wii and Gamecube through DevKitPro support, QNX, MontaVista, Tron variants, NonStop OS, OpenCL, Micrium's MicroC/OS-II, FreeRTOS, SafeRTOS, Freescale MQX, Nucleus, TinyOS, TI-RTOS, HP-UX, uTasker, uT-kernel, embOS, INtime, mbed, RIOT, CMSIS-RTOS, FROSTED, Green Hills INTEGRITY, Keil RTX, TOPPERS, PetaLinux, Apache Mynewt, and PikeOS.

History

The genesis of yaSSL, or yet another SSL, dates to 2004. OpenSSL was available at the time, and was dual licensed under the OpenSSL License and the SSLeay license. yaSSL, alternatively, was developed and dual-licensed under both a commercial license and the GPL. yaSSL offered a more modern API, commercial style developer support and was complete with an OpenSSL compatibility layer. The first major user of wolfSSL/CyaSSL/yaSSL was MySQL. Through bundling with MySQL, yaSSL has achieved extremely high distribution volumes in the millions.

Protocols

The wolfSSL lightweight SSL library implements the following protocols:
Protocol Notes:
wolfSSL uses the following cryptography libraries:

wolfCrypt

By default, wolfSSL uses the cryptographic services provided by wolfCrypt. wolfCrypt Provides RSA, ECC, DSS, Diffie–Hellman, EDH, NTRU, DES, Triple DES, AES, Camellia, IDEA, ARC4, HC-128, ChaCha20, MD2, MD4, MD5, SHA-1, SHA-2, SHA-3, BLAKE2, RIPEMD-160, Poly1305, Random Number Generation, Large Integer support, and base 16/64 encoding/decoding. An experimental cipher called Rabbit, a public domain software stream cipher from the EU's eSTREAM project, is also included. Rabbit is potentially useful to those encrypting streaming media in high performance, high demand environments.
wolfCrypt also includes support for the recent Curve25519 and Ed25519 algorithms.
wolfCrypt acts as a back-end crypto implementation for several popular software packages and libraries, including MIT Kerberos.

NTRU

CyaSSL+ includes NTRU public key encryption. The addition of NTRU in CyaSSL+ was a result of the partnership between yaSSL and Security Innovation. NTRU works well in mobile and embedded environments due to the reduced bit size needed to provide the same security as other public key systems. In addition, it's not known to be vulnerable to quantum attacks. Several cipher suites utilizing NTRU are available with CyaSSL+ including AES-256, RC4, and HC-128.

SGX

wolfSSL supports use of Intel SGX. Intel SGX allows for a smaller attack surface area and has been shown to provide a higher level of security for executing code without a significant negative impact on performance.

Hardware Acceleration Platforms Supported

Supported trusted elements

Currently, wolfSSL has the following as supported trusted elements:
The following tables list wolfSSL's support for using various devices' hardware encryption with various algorithms.
DeviceAES-GCMAES-CCMAES-CBCAES-ECBAES-CTR

AllAllAllAllAll

Cryptographic Accelerator and Assurance Module 		AllAllAllAll

All

K50, K60, K70, and K80 		AllAllAllAll
STMicroelectronics STM32
F1, F2, F4, L1, W Series 		AllAll

All

AllAllAll

AllAllAllAllAll

128-bit
AllAllAll
AllAll
AllAllAllAllAll
256-bit

- "All" denotes 128, 192, and 256-bit supported block sizes
DeviceDES-CBCDES-ECB3DES-CBC

64 bit192 bit

K50, K60, K70, and K80 		64 bit192 bit
STMicroelectronics STM32
F1, F2, F4, L1, W Series 		64 bit64 bit 192 bit

192 bit

64 bit192 bit

64 bit192 bit

DeviceMD5SHA1SHA2SHA-256SHA-384SHA-512
AVX1/AVX2
SupportedSupportedSupported

K50, K60, K70, and K80 		SupportedSupportedSupported
STMicroelectronics STM32
F1, F2, F4, L1, W Series 		SupportedSupported

SupportedSupportedSupported
Supported
SupportedSupportedSupported
SupportedSupported
Supported

DeviceHMAC-MD5HMAC-SHA1HMAC-SHA2HMAC-SHA256SHA-3Poly1305
AVX1/AVX2
Supported

SupportedSupportedSupportedSupported

SupportedSupportedSupported
SupportedSupported

Licensing

wolfSSL is open source, licensed under the GNU General Public License GPLv2.