hex_literal (https://docs.rs/hex-literal/0.3.1/hex_literal/) converts from String to concatenated hex numbers.
According to this RFC about WWW Authentication (used in HTTTP) RFC 2617 - HTTP Authentication: Basic and Digest Access Authentication,
For the purposes of this document, an MD5 digest of 128 bits is
represented as 32 ASCII printable characters. The bits in the 128 bit
digest are converted from most significant to least significant bit,
four bits at a time to their ASCII presentation as follows. Each four
bits is represented by its familiar hexadecimal notation from the
characters 0123456789abcdef. That is, binary 0000 gets represented by
the character '0', 0001, by '1', and so on up to the representation
of 1111 as 'f'.
How do I convert for this hash format from RFC? Why doesn't the md-5 crate has a simple feature that displays the digest as hexadecimal values?
literal_hex does the opposite: converts from String of hexadecimal concatenated values to bytes.