It supply variety of functions for all cryptograhic kinds such as symmetric ciphers (AES, DES, Blowfish, CAST5, Twofish, Arcfour), hash algorithms (MD4, MD5, RIPE-MD160, SHA-1, TIGER-192), MACs (HMAC for all hash algorithms), public key algorithms (RSA, ElGamal, DSA), large integer functions, random numbers and a lot of supporting functions. * Libgcrypt works on most POSIX systems and many pre-POSIX systems. * It can also be built using a cross-compiler system for Microsoft Windows.

• SSL version 3.0 and TLS versions 1.0, 1.1 and 1.2 (client and server) • DTLS 1.0, 1.2 support (client and server) • Minimum footprint size of 20-100 kB, depending on build options and operating environment • Runtime memory usage between 1-36 kB (depending on I/O buffer sizes, public key algorithm, and key size) • OpenSSL compatibility layer • OCSP and CRL support • Multiple Hashing Functions: MD2, MD4, MD5, SHA-1, SHA-2, SHA-256, SHA-384, SHA-512, BLAKE2b, RIPEMD-160, Poly1305 • Block, Stream, and Authenticated Ciphers: AES (CBC, CTR, GCM, CCM), Camellia, DES, 3DES, ARC4, RABBIT, HC-128, ChaCha20, IDEA • Public Key Options: RSA, DSS, DH, EDH, NTRU • Password-based Key Derivation: HMAC, PBKDF2, PKCS#5 • ECC Support ECDH-ECDSA, ECDHE-ECDSA, ECDH-RSA, ECDHE-RSA • RSA Key Generation • Curve25519 and Ed25519 • Client authentication support • PSK Pre-Shared Keys • Simple API • Persistent session and certificate cache • zlib compression support • Interchangeable crypto and certificate libraries • PEM and DER certificate support • x509 v3 RSA and ECC Signed Certificate Generation • PKCS #7 - Cryptographic Message Syntax (CMS) • PKCS #10 - Certificate Signing Request (CSR) • PKCS #8, #5, #12 Private Key Encryption • Supported TLS Extensions: SNI (Server Name Indication) Maximum Fragment Length Truncated HMAC Supported Elliptic Curves ALPN • Certificate Manager • QSH (quantum-safe handshake) extension • SRP (Secure Remote Password) • Hardware Cryptography Support Intel AES-NI support Cavium NITROX support STM32F2/F4 hardware crypto support Freescale CAU / mmCAU / SEC Microchip PIC32MZ • SSL Sniffer (SSL Inspection) Support • IPv4 and IPv6 support • Abstraction Layers / User Callbacks C Standard Library, Custom I/O, Memory hooks, Logging callbacks, User Atomic Record Layer Processing, Public Key • MySQL integration • Lighttpd, GoAhead, Mongoose web server support • stunnel support • OpenSSH support