Match the hash when hash is inserted as Vec<u8> [closed] - rust

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use sha3::{Digest, Keccak256};
fn reveal_vote(mut voter_id: Vec<u8>, mut phrase: Vec<u8>, vote_commit: Vec<u8>) {
let mut hyphen_vec = "-".as_bytes().to_vec();
voter_id.append(&mut hyphen_vec);
voter_id.append(&mut phrase);
let vote_bytes: &[u8] = &voter_id;
let mut hasher = Keccak256::new();
hasher.update(vote_bytes);
let result = hasher.finalize();
let vote_commit_bytes: &[u8] = &vote_commit;
if &result[..] == vote_commit_bytes {
println!("Data matched");
} else {
println!("data mismatched")
}
}
fn main() {
let vote_commit_string = "1-abcdef".as_bytes().to_vec();
let mut hasher = Keccak256::new();
hasher.update(vote_commit_string);
let result = hasher.finalize();
let commit = format!("{:x}", result); // e2a18e9b74f228590ca8c563cecfc58c28455b2dde25b4bbdc663e99e791f47c
let commit_vec = commit.as_bytes().to_vec();
println!("commit: {:?}", commit);
reveal_vote("1".as_bytes().to_vec(), "abcdef".as_bytes().to_vec(), commit_vec);
}
Want to check the hash matches, but both hash and string are in Vec<u8>,
but &result[..] == vote_commit_bytes doesnot match. How to check the equality?
https://docs.rs/sha3/0.9.1/sha3/

Answer 1

There is no equality, because apparently the format!() macro alters the data in some way (which I think is not totally unexpected).
The {:x} formatting option, formats the data as:
Debug with lower-case hexadecimal integers
so that is why those representations are not equal.
If you format both hash results in your code, it works as expected:
use sha3::{Digest, Keccak256};
fn reveal_vote(mut voter_id: Vec<u8>, mut phrase: Vec<u8>, vote_commit: Vec<u8>) {
let mut hyphen_vec = "-".as_bytes().to_vec();
voter_id.append(&mut hyphen_vec);
voter_id.append(&mut phrase);
let vote_bytes: &[u8] = &voter_id;
let mut hasher = Keccak256::new();
hasher.update(vote_bytes);
let result = hasher.finalize();
let vote_commit_bytes: &[u8] = &vote_commit;
let commit = format!("{:x}", result); // e2a18e9b74f228590ca8c563cecfc58c28455b2dde25b4bbdc663e99e791f47c
if commit.as_bytes().to_vec() == vote_commit_bytes {
println!("Data matched");
} else {
println!("data mismatched")
}
}
fn main() {
let vote_commit_string = "1-abcdef".as_bytes().to_vec();
let mut hasher = Keccak256::new();
hasher.update(vote_commit_string);
let result = hasher.finalize();
let commit = format!("{:x}", result); // e2a18e9b74f228590ca8c563cecfc58c28455b2dde25b4bbdc663e99e791f47c
let commit_vec = commit.as_bytes().to_vec();
println!("commit: {:?}", commit);
reveal_vote("1".as_bytes().to_vec(), "abcdef".as_bytes().to_vec(), commit_vec);
}

Answer 2

Sorry, old question, solved it using hex
use sha3::{Digest, Keccak256};
use hex;
fn reveal_vote(mut voter_id: Vec<u8>, mut phrase: Vec<u8>, vote_commit: Vec<u8>) {
let mut hyphen_vec = "-".as_bytes().to_vec();
voter_id.append(&mut hyphen_vec);
voter_id.append(&mut phrase);
let vote_bytes: &[u8] = &voter_id;
let mut hasher = Keccak256::new();
hasher.update(vote_bytes);
let result = hasher.finalize();
if hex::encode(result).as_bytes().to_vec() == vote_commit {
println!("Data matched");
} else {
println!("data mismatched")
}
}
fn main() {
let vote_commit_string = "1-abcdef".as_bytes().to_vec();
let mut hasher = Keccak256::new();
hasher.update(vote_commit_string);
let result = hasher.finalize();
println!("{:?}", result);
println!("{:?}", &result[..]);
let commit = format!("{:x}", result); // e2a18e9b74f228590ca8c563cecfc58c28455b2dde25b4bbdc663e99e791f47c
let commit_vec = commit.as_bytes().to_vec();
// println!("commit: {:?}", commit);
println!("commit_vec: {:?}", commit_vec);
reveal_vote("1".as_bytes().to_vec(), "abcdef".as_bytes().to_vec(), commit_vec);
}