sha1

A from-scratch implementation of the SHA-1 hash algorithm in Rust, following RFC 3174 (US Secure Hash Algorithm 1, SHA1).

What it does

Computes the SHA-1 digest of a hardcoded input (b"mukul") and prints it as a hex string. The implementation covers:

• Message padding (pad_sha1) per RFC 3174 section 4
• Message schedule expansion into 80 32-bit words (create_words)
• The four rounds of nonlinear functions f(t, b, c, d) (section 5)
• The round constants k(t) (section 5)
• The main compression loop over 80 rounds, producing the final 160-bit digest

Usage

cargo run

Reference

• RFC 3174 — US Secure Hash Algorithm 1 (SHA1)