This article explains how to calculate checksum using ESXi shell.
VMware vSphere ESXi
md5sum, sha1sum, sha256sum, sha512sum are available in ESXi shell.
# Command example
[root@localhost:~] md5sum zero
d41d8cd98f00b204e9800998ecf8427e zero
[root@localhost:~] sha1sum zero
da39a3ee5e6b4b0d3255bfef95601890afd80709 zero
[root@localhost:~] sha256sum zero
e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 zero
[root@localhost:~] sha512sum zero
cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e zero