SHA

C++ implementation of SHA-1 and SHA-2 Cryptographic Hash Algorithms.

Overview

• SHA-1: [ SHA-1 ]

• SHA-2: [ SHA-224, SHA-256, SHA-384, SHA-512, SHA-512/224, SHA-512/256 ]

Getting Started

SHA-1 Hash Algorithm

Implementation in accordance with NIST FIPS PUB 180-4 standard.

sha1.cpp

sha1('hello world')
> '2aae6c35c94fcfb415dbe95f408b9ce91ee846ed'

Hashing Process

1. Pre Process

   • Convert each character from message to 8-bits and append to data. Then append a single 1.
   • Pad data with 0's until it is a multiple of 512-bits.
   • Use the last 64-bits of data to represent the length of message.

2. Chunk Loop

   • Break data into 32-bit sections and save all sections to blocks.
   • Append 64 0's to blocks.

3. Compression Loop

   • Modify the 0's added in step 2 following SHA-1 hash computation procedures. [6.1.0].

4. Mutation Loop

   • Initialize all 8 hash_constants to a b c d e respectively.
   • Modify a-e using the values in blocks and values in round_constants following SHA-1 hash computation procedures. [6.1.0].
   • Repeat previous step once for each value in round_constants.
     (x80 iterations)

5. Concatenation

   • Concatenate newly modified values in hash_constants to create digest.
   • Return digest to user.

SHA-2 Hash Algorithms

Implementations in accordance with NIST FIPS PUB 180-4 standard.

sha2.cpp

sha224('hello world') 
> '2f05477fc24bb4faefd86517156dafdecec45b8ad3cf2522a563582b'

sha256('hello world')
> 'b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9'

sha384('hello world')
> 'fdbd8e75a67f29f701a4e040385e2e23986303ea10239211af907fcbb83578b3e417cb71ce646efd0819dd8c088de1bd'

sha512('hello world')
> '309ecc489c12d6eb4cc40f50c902f2b4d0ed77ee511a7c7a9bcd3ca86d4cd86f989dd35bc5ff499670da34255b45b0cfd830e81f605dcf7dc5542e93ae9cd76f'

sha512_224('hello world')
> '22e0d52336f64a998085078b05a6e37b26f8120f43bf4db4c43a64ee'

sha512_256('hello world')
> '0ac561fac838104e3f2e4ad107b4bee3e938bf15f2b15f009ccccd61a913f017'

Hashing Process

• 32-bit [ SHA-224, SHA-256 ]
• 64-bit [ SHA-384, SHA-512, SHA-512/224, SHA-512/256 ]

1. Pre Process

   • Convert each character from message to 8-bits and append to data. Then append a single 1.
   • Pad data with 0's until it is a multiple of 512-bits (32-bit) or a multiple of 1024-bits (64-bit).
   • Use the last 64-bits (32-bit) or 128-bits (64-bit) of data to represent the length of message.

2. Chunk Loop

   • Break data into 32-bit (32-bit) or 64-bit (64-bit) sections and save all sections to blocks.
   • Append 48 0's (32-bit) or 80 0's (64-bit) to blocks.

3. Compression Loop

   • Modify the 0's added in step 2 following SHA-2 hash computation procedures.
     (32-bit [6.2.2]. 64-bit [6.4.2])

4. Mutation Loop

   • Initialize all 8 hash_constants to a b c d e f g h respectively.
   • Modify a-h using the values in blocks and values in round_constants following SHA-2 hash computation procedures.
     (32-bit [6.2.2]. 64-bit [6.4.2])
   • Repeat previous step once for each value in round_constants.
     (32-bit: x64 iterations | 64-bit: x80 iterations)

5. Concatenation

   • Concatenate newly modified values in hash_constants to create digest.
   • Return digest to user.