Implementation borrowed from the
https://github.com/ARMmbed/mbedtls.git project (v3.1.0)
Speed testing (Xeon(R) CPU E3-1230 V2 @ 3.30GHz):
gcrypt-gnu Test md 2897 ms enc 2777 ms dec 942 ms
gcrypt-int Test md 3668 ms enc 1312 ms dec 2836 ms
gcrypt-int-noaesni Test md 3652 ms enc 1916 ms dec 4458 ms
gcrypt-gnu-nonopt Test md 3763 ms enc 4978 ms dec 3999 ms
gcrypt-gnu-nonopt - libgcrypt compiled without hardware acceleration
--disable-padlock-support --disable-aesni-support \
--disable-shaext-support --disable-pclmul-support \
--disable-sse41-support --disable-drng-support \
--disable-avx-support --disable-avx2-support \
--disable-neon-support --disable-arm-crypto-support \
--disable-ppc-crypto-support
--disable-amd64-as-feature-detection
