Libgcrypt is a general purpose cryptographic library originally based on code from GnuPG. It provides functions for all cryptograhic building blocks: symmetric cipher algorithms (AES, Arcfour, Blowfish, Camellia, CAST5, ChaCha20 DES, GOST28147, Salsa20, SEED, Serpent, Twofish) and modes (ECB,CFB,CBC,OFB,CTR,CCM,GCM,OCB,POLY1305,AESWRAP), hash algorithms (MD2, MD4, MD5, GOST R 34.11, RIPE-MD160, SHA-1, SHA2-224, SHA2-256, SHA2-384, SHA2-512, SHA3-224, SHA3-256, SHA3-384, SHA3-512, SHAKE-128, SHAKE-256, TIGER-192, Whirlpool), MACs (HMAC for all hash algorithms, CMAC for all cipher algorithms, GMAC-AES, GMAC-CAMELLIA, GMAC-TWOFISH, GMAC-SERPENT, GMAC-SEED, Poly1305, Poly1305-AES, Poly1305-CAMELLIA, Poly1305-TWOFISH, Poly1305-SERPENT, Poly1305-SEED), public key algorithms (RSA, Elgamal, DSA, ECDSA, EdDSA, ECDH), 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.
See also its Wikipedia entry.
Due to former U.S. export restrictions on cryptographic software, the software is not distributed via the standard GNU archives but from the European based GnuPG server.
The current stable version is 1.8.4 which was released on 2018-10-26. See the download section for the latest tarball.
All versions of Libgcrypt since 1.2 are API and ABI compatible. The 1.6 series reached end-of-life on 2017-06-30. The 1.7 series will receive updates for severe bugs and security problems until 2019-06-30.
Libgcrypt is distributed under the terms of the GNU Lesser General Public License (LGPLv2.1+). The helper programs as well as the documentation are distributed under the terms of the GNU General Public License (GPLv2+). The file LICENSES has notices about contributions that require that these additional notices are distributed.