Category: Blockchain

use sha2::{Digest, Sha256};

#[derive(Debug, Clone)]
enum Position {
    Right,
    Left,
}

#[derive(Debug, Clone)]
struct Node {
    left: String,
    right: String,
    parent: String,
    sibling: String,
    position: Position,
    data: String,
}

fn hash(data: String) -> String {
    let h = Sha256::digest(data.clone());
    hex::encode(h).to_string()
}

fn sha256hash(right_data: String, left_data: String) -> String {
        let s = format!("{}{}", right_data, left_data);
        let h = Sha256::digest(s);
        hex::encode(h).to_string()
}

#[derive(Debug, Clone)]
struct Tree {
    leaves: Vec<Node>,
    layer: Vec<Node>,
    root: String,
}

impl Tree {
    fn build_layer(&mut self) {
        let mut new_layer: Vec<Node> = Vec::new();

        if self.layer.len() % 2 == 1 {
            self.layer.push(self.layer[self.layer.len() - 1].clone());
        }

        for i in (0..self.layer.len()).step_by(2) {
            let parent_data = sha256hash(self.layer[i].data.clone(), self.layer[i+1].data.clone());
            let left = Node {left: "".to_string(), right: "".to_string(), parent: parent_data.clone(), sibling: self.layer[i+1].data.clone(), position: Position::Left, data: self.layer[i].data.clone()};
            let right = Node {left: "".to_string(), right: "".to_string(), parent: parent_data.clone(), sibling: self.layer[i].data.clone(), position: Position::Right, data: self.layer[i+1].data.clone()};
            let parent = Node {left: self.layer[i].data.clone(), right: self.layer[i+1].data.clone(), parent: "".to_string(), sibling: self.layer[i].data.clone(), position: Position::Left, data: parent_data.clone()};
            new_layer.push(parent.clone());
            self.leaves.push(left.clone());
            self.leaves.push(right.clone());
            self.leaves.push(parent.clone());
        }
        self.layer = new_layer;
    }

    fn build_tree(&mut self) {
        while self.layer.len() > 1 {
            let _ = self.build_layer();
        }
        self.root = self.layer[0].data.clone();
    }

    fn search(&mut self, data: String) -> Node {
        let hash_value = data.clone();
        let mut target = Node {left: "".to_string(), right: "".to_string(), parent: "".to_string(), sibling: "".to_string(), position: Position::Left, data: "".to_string()};
        for node in &self.leaves {
            if node.data == hash_value {
                let target: Node = node.clone();
            } 
        }
        return target
    }

    fn get_pass(&mut self, data: String) -> Vec<String>{
        let mut target = self.search(hash(data.clone()));
        let mut markle_pass: Vec<String> = Vec::new();
        markle_pass.push(target.data);
        while target.parent != "" {
            markle_pass.push(target.sibling);
            target = self.search(target.parent);
        }       
        return markle_pass
    }
}

fn merkle_root(v: Vec<&str>) -> String {
    let mut t = Tree {leaves: [].to_vec(), layer: [].to_vec(), root: "".to_string()};
    for n in v {
        let mut s =  Node {left: "".to_string(), right: "".to_string(), parent: "".to_string(), sibling: "".to_string(), position: Position::Left, data: hash(n.to_string())};
        t.layer.push(s.clone());
    }
    t.build_tree();
    t.root
}

fn main(){
    let v= vec!["aaa", "bbb", "ccc", "ddd", "eee", "fff", "gggg"];
    let m = merkle_root(v);
    println!("{}", m);
}

うーん….

writeln!でpemファイルを作成します。

env::set_var("RUST_BACKTRACE", "1");
    let secret_key = SigningKey::random(&mut OsRng);
    let secret_key_serialized = secret_key
        .to_pkcs8_pem(Default::default())
        .unwrap()
        .to_string();
    println!("Secret Key: \n{}", secret_key_serialized);

    let mut file = File::create("secret.pem").expect("file not found.");

    writeln!(file, "{}", secret_key_serialized).expect("can not write.");

すると、最後尾に2行改行が入ってしまいます。

-----BEGIN PRIVATE KEY-----
MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgO7s4/UmqJ5+UWIIU
oL4XIxslh+htWtvTY7wZPp+usEKhRANCAAS/iV6WinhhKw8M/tkGNNwf2W+Vt+cd
d0hLjWQ9iZhjP7NxlPLoUjWERctvft3zPOktCedW5rzLIhVtj7rX2F4j
-----END PRIVATE KEY-----

これをstd::fs::read_to_stringで読み取ってパースしても、改行が入っているためエラーになってしまいます。
改行を指定しての文字列削除や文字列の置き換え(s.replace)だとうまくいかないのですが、
trim()だと、いい具合に最後2行の改行を削除してくれます。

    let mut file = File::create("secret.pem").expect("file not found.");

    writeln!(file, "{}", secret_key_serialized).expect("can not write.");

    let contents = std::fs::read_to_string("secret.pem")
        .expect("something went wrong reading the file");
    let secret_pem = contents.trim();
    println!("{}", secret_pem);

Secret Key:
—–BEGIN PRIVATE KEY—–
MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgNMDcEubwpsVrs/TJ
YgiL/HFyb3hvOgF/QI3AwXWBFKmhRANCAARyuwFIbkPm5Q1zbd6DZbNMG35s7NmU
6QduJGRjofpwCrVaOorsjZASpG546WgoTof9eONpXYY92NY5hCvhPJrU
—–END PRIVATE KEY—–

—–BEGIN PRIVATE KEY—–
MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgNMDcEubwpsVrs/TJ
YgiL/HFyb3hvOgF/QI3AwXWBFKmhRANCAARyuwFIbkPm5Q1zbd6DZbNMG35s7NmU
6QduJGRjofpwCrVaOorsjZASpG546WgoTof9eONpXYY92NY5hCvhPJrU
—–END PRIVATE KEY—–

素晴らしいですね。これ解決するのに半日かかりました。

use p256::{
    ecdsa::{
        signature::{Signer, Verifier},
        SigningKey, VerifyingKey,
    },
    pkcs8::EncodePrivateKey,
    PublicKey, SecretKey,
};
use rand_core::OsRng;
use std::fs::OpenOptions;
use std::io::Write;

fn main(){
    let secret_key = SigningKey::random(&mut OsRng);
    let secret_key_serialized = secret_key
        .to_pkcs8_pem(Default::default())
        .unwrap()
        .to_string();
    println!("Secret Key: \n{}", secret_key_serialized);
    let secret_key = secret_key_serialized.parse::<SecretKey>().unwrap();

    let public_key = secret_key.public_key();
    let public_key_serialized = public_key.to_string();
    println!("Public Key: \n{}", public_key_serialized);
    let public_key = public_key_serialized.parse::<PublicKey>().unwrap();

    let signing_key: SigningKey = secret_key.into();
    let message = b"ECDSA proves knowledge of a secret number in the context of a single message";
    let signature = signing_key.sign(message);

    let verifying_key: VerifyingKey = public_key.into();
    assert!(verifying_key.verify(message, &signature).is_ok());
}

Finished `dev` profile [unoptimized + debuginfo] target(s) in 5.89s
Running `target/debug/sample`
Secret Key:
—–BEGIN PRIVATE KEY—–
MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgqmVTGsuHMDgaN3TG
Jvsem2P1dA3l/wnRsxPfN8PTnUqhRANCAASv58iralPg2mOjuf28sSC8UuxqR4kD
u9tATiYXDvaU6BfmuI0tl0JsrZ2Brf1BkXtzbwBbiM2+h6+I6J55TU2p
—–END PRIVATE KEY—–

Public Key:
—–BEGIN PUBLIC KEY—–
MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEr+fIq2pT4Npjo7n9vLEgvFLsakeJ
A7vbQE4mFw72lOgX5riNLZdCbK2dga39QZF7c28AW4jNvoeviOieeU1NqQ==
—–END PUBLIC KEY—–

p256とk256は微妙に違うのね。。これをpemファイルとして保存したい。

templates/withdrawal.html

<form action="/sent" method="post" class="">
            <input type="hidden" name="time" id="time" value="">
            <input type="hidden" name="sender" value="{{address}}">
            <div class="mb-3">
                <label for="receiver" class="form-label">送付先アドレス</label>
                <input type="text" class="form-control" id="receiver" name="receiver" placeholder="送付先のアドレスを入力してください">
              </div>
              <div class="mb-3">
                <label for="amount" class="form-label">送付コイン量</label>
                <input type="text" class="form-control" id="amount" name="amount" placeholder="数量を半角数字で入力してください。e.g. 1000">
              </div>
              <input type="submit" value="送信" class="btn btn-primary"/>
        </form>

#[derive(Serialize, Deserialize, Debug)]
struct UnsignedTransaction {
    time: String,
    sender: String,
    receiver: String,
    amount: i32,
}
// 
async fn handle_sent(axum::Form(unsignedtransaction): axum::Form<UnsignedTransaction>)
    -> axum::response::Html<String> {

    let tera = tera::Tera::new("templates/*").unwrap();

    let mut context = tera::Context::new();
    context.insert("time", &unsignedtransaction.time);
    context.insert("receiver", &unsignedtransaction.receiver);
    context.insert("amount", &unsignedtransaction.amount);

    let output = tera.render("sent.html", &context);
    axum::response::Html(output.unwrap())
}

formのPOSTはできました。
このデータを受け取ったタイミングで、外部のIP(node)に合わせてPOSTしたい。

templates/account.html

   <body class="container">
        <h1 class="display-6 my-2">Crypt Wallet</h1>
        <hr>
        <nav aria-label="breadcrumb">
            <ol class="breadcrumb">
              <li class="breadcrumb-item"><a href="/">Home</a></li>
              <li class="breadcrumb-item"><a href="/account">アカウント情報</a></li>
            </ol>
          </nav>
        <div class="alert alert-primary">
            <p class="my-2">秘密鍵、公開鍵、アドレスを生成しました。</p>
        </div>
        <dl class="row">
            <dt class="col-sm-3">秘密鍵</dt>
            <dd class="col-sm-9">{{private_key}}</dd>
          
            <dt class="col-sm-3">公開鍵</dt>
            <dd class="col-sm-9">{{public_key}}</dd>
          
            <dt class="col-sm-3">アドレス</dt>
            <dd class="col-sm-9">{{address}}</dd>
          
          </dl>
        <br><br>
        <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/js/bootstrap.bundle.min.js" integrity="sha384-geWF76RCwLtnZ8qwWowPQNguL3RmwHVBC9FhGdlKrxdiJJigb/j/68SIy3Te4Bkz" crossorigin="anonymous"></script>
    </body>

async fn handle_account()-> axum::response::Html<String> {

    let signing_key = SigningKey::random(&mut OsRng);
    let private_key = hex::encode(signing_key.to_bytes());
    let verifying_key = signing_key.verifying_key();
    let public_key = hex::encode(verifying_key.to_sec1_bytes());
    let address = new_address(&verifying_key);    

    let tera = tera::Tera::new("templates/*").unwrap();
    let mut context = tera::Context::new();
    context.insert("private_key", &private_key);
    context.insert("public_key", &public_key);
    context.insert("address", &address);

    let output = tera.render("account.html", &context);
    axum::response::Html(output.unwrap())
}

リファクタリングが必要だけど、やりたいことは大体できている^^

use k256::{ecdsa::{SigningKey, Signature, signature::Signer, signature::Verifier, VerifyingKey}};
use rand_core::OsRng;
use sha2::{Digest, Sha256};
use ripemd::{Ripemd160};

fn new_keys() {
    let signing_key = SigningKey::random(&mut OsRng);
    let private_key = hex::encode(signing_key.to_bytes());
    println!("private key: {:x?}", private_key);
    let verifying_key = signing_key.verifying_key();
    let public_key = hex::encode(verifying_key.to_sec1_bytes());
    println!("public key: {:x?}", public_key);

    new_address(&verifying_key);    
}   

fn new_address(verifying_key: &VerifyingKey) {

    let vk = verifying_key.to_sec1_bytes();

    let mut hasher = Sha256::new();
    hasher.update(vk);
    let hashed_sha256 = hasher.finalize();

    let mut hasher = Ripemd160::new();
    hasher.update(hashed_sha256);
    let account_id = hasher.finalize();

    let mut payload = account_id.to_vec();
    payload.insert(0, 0x00);

    let mut hasher = Sha256::new();
    hasher.update(&payload);
    let hash = hasher.finalize();

    let mut hasher = Sha256::new();
    hasher.update(hash);
    let checksum = hasher.finalize();

    payload.append(&mut checksum[0..4].to_vec());

    const ALPHABET: &str = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
    let address = base_x::encode(ALPHABET, &payload);

    println!("address: {:?}", address);
}


fn main() {
    new_keys();
}

$ cargo run
…
private key: “745aa1c916085b2e3423dc7a22792945bae57c38bd5bc1bb0426ba2156f8a39c”
public key: “029e1baf2992b44af147c306fb728f8b00e908aa7f09e25eaa0a2fed3f71ad4cf6”
address: “1E5b59jN4nyM9kpzqdXfW7MkLJ2CApAVjT”

これをWebフレームワークで表現したい。使うのはaxumかな。。。