Projects / CyaSSL


The CyaSSL embedded SSL library is a lightweight SSL library written in ANSI C and targeted for embedded and RTOS environments, primarily because of its small size, speed, and feature set. It is commonly used in standard operating environments and cloud services as well because of its royalty-free pricing and excellent cross platform support. CyaSSL supports industry standards up to the current TLS 1.2 and DTLS 1.2 levels, is up to 20 times smaller than OpenSSL, and offers progressive ciphers such as HC-128, RABBIT, and NTRU.

Operating Systems

Last announcement

Updated CyaSSL Porting Guide Available 21 Nov 2013 16:15

As a large number of our users port CyaSSL to new platforms and environments, we’ve put some time into updating our CyaSSL Porting Guide and have made it available both online and in PDF version. You can find the updated guide here: If you have any questions about content in the Porting Guide, or about the CyaSSL lightweight SSL library in general, please reach out to us at

Recent releases

  •  10 Apr 2014 17:56

    Release Notes: This release has bugfixes, including security fixes. Other features and fixes in this release include sniffer fixes for corrupted packet length and Jumbo frames, ARM thumb mode assembly fixes, Xcode 5.1 support including new clang, PIC32 MZ hardware support, CyaSSL Object having enough room to read the Record Header now without allocs, FIPS wrappers for several algorithms/functions, and more.

    •  10 Feb 2014 17:33

      Release Notes: This release adds Freescale RNGA, RNGB, and mmCAU support, new TLS extensions (ECC, Truncated HMAC), SCEP support with partial PKCS#7 support, PKCS#10 Certificate Signing Request generation, DTLS sliding window, OCSP improvements, GMAC hashing, Windows build fixes, Microchip MPLAB Harmony support, ECC encrypt/decrypt primitives, ECC certificate generation, and more.

      •  21 Nov 2013 16:10

        Release Notes: This release adds enhanced AES-NI support, NetX support, IPv6 DTLS fixes, SEP cert extensions, Atomic Record Layer Processing, Public Key callbacks, and more.

        •  25 Jun 2013 15:47

          Release Notes: This release adds SNI, Keil MDK-ARM project files, wildcard and Subject altname domain name checks, persistent session and certificate cache, DTLS reliability enhancements, and much more.

          •  06 Feb 2013 21:39

            Release Notes: This release includes bugfixes, a fix for the "Lucky 13" TLS CBC padding timing attack, Microchip PIC32 support, MPLAB X example project files for the PIC32 Ethernet Starter Kit, an updated CTaoCrypt benchmark app for embedded systems, 1024-bit test certs/keys and cert/key buffers, AES-CCM-8 crypto and cipher suites, Camellia crypto and cipher suites, OCSP callbacks, STM32F2 support with hardware crypto and RNG, and Cavium NITROX support.


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