Rust

Example: Hash Text in Chunks

Shows how to generate a final hash, like SHA-256, for a large text by processing it in chunks. Rust

let crypt = chilkat::Crypt2::new();
crypt.set_hash_algorithm("sha256");
crypt.set_charset("utf-8");

let bd = chilkat::BinData::new();

let s = "The quick brown fox jumped over the lazy dog.\r\n".to_string();

// Accumulate the text in a StringBuilder.  We'll demonstrate hashing the text in chunks,
// and then also hashing the entire text at once to show the results are the same.

let _ = bd.append_string(&s, "utf-8");
let _ = crypt.hash_begin_string(&s).is_ok();

let mut i = 0;
while i < 200 {
    let _ = bd.append_string(&s, "utf-8");
    let _ = crypt.hash_more_string(&s);
    i = i + 1;
}

// Get the hash in base64 format.
crypt.set_encoding_mode("base64");

let mut encoded_hash = crypt.hash_final_enc().unwrap_or_default();
println!("Hash computed in chunks: {}", encoded_hash);

// Let's alternatively compute the hash of the entire amount of data at once,
// to show the hash computation is the same:
encoded_hash = crypt.hash_bd_enc(&bd).unwrap_or_default();
println!("Hash computed in 1 step: {}", encoded_hash);

// Output:

// Hash computed in chunks: unwkVff61k40roRIJizaknreScHaL6frWe37kydXbZQ=
// Hash computed in 1 step: unwkVff61k40roRIJizaknreScHaL6frWe37kydXbZQ=