SHA1 - NIST FIPS-180 2 NSRL Test Data

[WingZer0o]

https://www.nist.gov/itl/ssd/software-quality-group/nsrl-test-data

I was doing some more reading on the topic of conversation for FIPS and wanted to try and implement some more code. I propose that we add 3 tests that are specified in the above document for SHA1.

• A file containing the ASCII string "abc" results in a 160 bit message digest of a9993e36 4706816a ba3e2571 7850c26c 9cd0d89d.
• A file containing the ASCII string "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"results in a 160-bit message digest of 84983e44 1c3bd26e baae4aa1 f95129e5 e54670f1.
• A file containing the binary-coded form of the ASCII string which consists of 1,000,000 repetitions of the character "a" results in a SHA-1 message digest of 34aa973c d4c4daa4 f61eeb2b dbad2731 6534016f.

[newpavlov]

We already test the "abc" and "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq" vectors as part of the sha1_kat test. I think we previously had the 1 million "a" test, but intentionally replaced it with sha1_rand.

Finally, use of the hex crate and std items is unnecessary.

[WingZer0o]

@newpavlov Thanks for the feedback! I'll look into it a little more.