Files common to both hss_verify and xmssmt_verify

• README.md - This file.
• endian_utils.c/h - Functions related to reading/writing big endian values
• hash_wrappers.c/h - Functions related to hashing
• sha256.c/h - Functions related to the SHA256 hashing function
• sha256asm.s - Optimized ARM assembly language implementation of SHA256

You can enable the use of an optimized ARM assembly language implementation of SHA256 by undefining the QUARK_USE_SHA256_C flag in quark_sha256.c. This will swap out the C-based compression function for an optimized ASM version.

The scratch buffer is used to deal with the lack of dynamic allocation within functions.