I'm trying to find a good library for calculating sha256. I found already a lot of options
crypto++ : http://www.cryptopp.com/
openSSL: http://www.openssl.org/
MIRACL: http://www.shamus.ie/
I would much prefer a library that's well-known, widely industrially used and works on all operating systems, rather than the most efficient one.
What do you recommend for me? (feel free to recommend on a library that I didn't mention here).
You should consider cryptlib
Works on all operating systems
Cryptlib is supplied as source code for AMX, BeOS, ChorusOS, DOS, DOS32, eCOS, µC/OS-II, embedded Linux, FreeRTOS/OpenRTOS, IBM MVS, µITRON, Macintosh/OS X, OS/2, PalmOS, RTEMS, Tandem, ThreadX, a variety of Unix versions (including AIX, Digital Unix, DGUX, FreeBSD/NetBSD/OpenBSD, HP-UX, IRIX, Linux, MP-RAS, OSF/1, QNX, SCO/UnixWare, Solaris, SunOS, Ultrix, and UTS4), uClinux, VM/CMS, VxWorks, Windows 3.x, Windows 95/98/ME, Windows CE/PocketPC/SmartPhone, Windows NT/2000/XP/Vista/Windows 7 (32- and 64-bit versions), VDK, and Xilinx XMK. cryptlib’s highly portable nature means that it is also being used in a variety of custom embedded system environments.
Widely industrially used
see Clients
It's not free for commercial use, though.