Heimdal libhcrypto library is a implementation many crypto algorithms, among others: AES, SHA, DES, RSA, Camellia and many help function.
hcrypto provies a OpenSSL compatible interface libcrypto interface and is licensed under a 3 clause BSD license (GPL compatible).
The project web page: http://www.h5l.org/
Sections of this manual:
Older interfaces that you should not use:
Functions controlling general behavior, like adding algorithms, are documented in this module: hcrypto function controlling behavior .
Return values are diffrent in this module to be compatible with OpenSSL interface. The diffrence is that on success 1 is returned instead of the customary 0.
Eric Young implemented DES in the library libdes, that grew into libcrypto in the ssleay package. ssleay went into recession and then got picked up by the OpenSSL (htp://www.openssl.org/) project.
libhcrypto is an independent implementation with no code decended from ssleay/openssl. Both includes some common imported code, for example the AES implementation.