An implementation of the SHA-2 cryptographic hash algorithms.

There are 6 standard algorithms specified in the SHA-2 standard:

• Sha224, which is the 32-bit Sha256 algorithm with the result truncated to 224 bits.
• Sha256, which is the 32-bit Sha256 algorithm.
• Sha384, which is the 64-bit Sha512 algorithm with the result truncated to 384 bits.
• Sha512, which is the 64-bit Sha512 algorithm.
• Sha512Trunc224, which is the 64-bit Sha512 algorithm with the result truncated to 224 bits.
• Sha512Trunc256, which is the 64-bit Sha512 algorithm with the result truncated to 256 bits.

Algorithmically, there are only 2 core algorithms: Sha256 and Sha512. All other algorithms are just applications of these with different initial hash values, and truncated to different digest bit lengths.

Usage

An example of using Sha256 is:

use sha2::{Sha256, Digest};

// create a Sha256 object
let mut hasher = Sha256::default();

// write input message
hasher.input(b"hello world");

// read hash digest and consume hasher
let output = hasher.result();

assert_eq!(output[..], [0xb9, 0x4d, 0x27, 0xb9, 0x93, 0x4d, 0x3e, 0x08,
                        0xa5, 0x2e, 0x52, 0xd7, 0xda, 0x7d, 0xab, 0xfa,
                        0xc4, 0x84, 0xef, 0xe3, 0x7a, 0x53, 0x80, 0xee,
                        0x90, 0x88, 0xf7, 0xac, 0xe2, 0xef, 0xcd, 0xe9]);

An example of using Sha512 is:

use sha2::{Sha512, Digest};

// create a Sha512 object
let mut hasher = Sha512::default();

// write input message
hasher.input(b"hello world");

// read hash digest and consume hasher
let output = hasher.result();

assert_eq!(output[..], [0x30, 0x9e, 0xcc, 0x48, 0x9c, 0x12, 0xd6, 0xeb,
                        0x4c, 0xc4, 0x0f, 0x50, 0xc9, 0x02, 0xf2, 0xb4,
                        0xd0, 0xed, 0x77, 0xee, 0x51, 0x1a, 0x7c, 0x7a,
                        0x9b, 0xcd, 0x3c, 0xa8, 0x6d, 0x4c, 0xd8, 0x6f,
                        0x98, 0x9d, 0xd3, 0x5b, 0xc5, 0xff, 0x49, 0x96,
                        0x70, 0xda, 0x34, 0x25, 0x5b, 0x45, 0xb0, 0xcf,
                        0xd8, 0x30, 0xe8, 0x1f, 0x60, 0x5d, 0xcf, 0x7d,
                        0xc5, 0x54, 0x2e, 0x93, 0xae, 0x9c, 0xd7, 0x6f][..]);