How to import a public key which is made with ECDSA?

[zcqzcg]

Hi there,
First thanks for the amazing effort in this pakcage, it's really saving my day.

Well here seems to be some problems with my code.

what I can do:

• import a privateKey
• use it to generate a new publicKey, and de/encrypt works like a charming.

what I want:

• import the publicKey and the privateKey at the same time
• use them to de/encrypt, don't have to generate a new one

The code under blow is as far as I can get. It's a bit of ugly, please don't laugh at me for me being a rookie.

var keyUtils = require('js-crypto-key-utils');
var eccrypto = require("eccrypto");


var privKeyA = `-----BEGIN PRIVATE KEY-----
MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgYYZNfKK0D3KJUE45
m7mBYQsH+iOu3IuzwK2W21/3lQChRANCAAT0SdzISybvGSWhwokYCndUAYwSPIkE
LuvZ2y9CBGO6PGGRvWJTvklrMfaALSxFlcXpdSfnB5ieBrht+qspmGBC
-----END PRIVATE KEY-----`;
var pubKeyA = `-----BEGIN PUBLIC KEY-----
MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE9EncyEsm7xklocKJGAp3VAGMEjyJ
BC7r2dsvQgRjujxhkb1iU75JazH2gC0sRZXF6XUn5weYnga4bfqrKZhgQg==
-----END PUBLIC KEY-----`;

const pubKeyObjFromPemA = new keyUtils.Key('pem', pubKeyA);
// console.log(pubKeyObjFromPemA);
const prvKeyObjFromPemA = new keyUtils.Key('pem', privKeyA);
// console.log(prvKeyObjFromPemA);



async function foo() {

    let prvKeyJWKA = await prvKeyObjFromPemA.export('oct');
    let pubKeyJWKA = await pubKeyObjFromPemA.export('oct');

    // console.log(prvKeyJWKA);
    // console.log(pubKeyJWKA);

    // let pubAHex = Array.prototype.map.call(pubKeyJWKA, x => ('00' + x.toString(16)).slice(-2)).join('');

    var privateKeyA = Buffer.from(prvKeyJWKA);

    var publicKeyA = Buffer.from(pubKeyJWKA);
    console.log(publicKeyA.toString('hex'));

    let pubAHex = Array.prototype.map.call(publicKeyA, x => ('00' + x.toString(16)).slice(-2)).join('');
    console.log(pubAHex);

    publicKeyA = eccrypto.getPublic(privateKeyA);
    console.log(publicKeyA.toString('hex'));

    // Encrypting the message for A.
    let encrypted = await eccrypto.encrypt(publicKeyA, Buffer.from("msg to a asdasdasdasd"));

    console.log(encrypted.ciphertext.toString());

    let plaintext = await eccrypto.decrypt(privateKeyA, encrypted);

    console.log(plaintext.toString())

}


foo();

and here is what I got from the last run :

04f449dcc84b26ef1925a1c289180a7754018c123c89042eebd9db2f420463ba3c6191bd6253be496b31f6802d2c4595c5e97527e707989e06b86dfaab29986042
04f449dcc84b26ef1925a1c289180a7754018c123c89042eebd9db2f420463ba3c6191bd6253be496b31f6802d2c4595c5e97527e707989e06b86dfaab29986042
04f8d2d188ba947c54af0607e689258f2bdd7ab99027752975915b1baf56a9bf8c35c23fe2b0dc53999c60a963b317eabcd0bbdf612359906737d1173a1d386e0c
������ӆ�s������>�w�$���v�_�O)�d
msg to a asdasdasdasd

I really hope you may help me with this issue. Also if it's not happening by some reason, that's ok, I can just save another publicKey for the encryption using.

Thanks again for your time,
David

[JBaczuk]

I'm not sure I understand the problem, if you already have the private key, why not just generate the public key? It's deterministic. Are you sure that pem public key is correct?

[zcqzcg]

Now I have a pair of ecdsa keys;

and if I want to use the ecc encrypt/decrypt, I will have to generate a new ecc-publicKey from the privateKey , which I already have a ecdsa-publicKey in hand.

So now I have ecdsaPrivateKey, ecdsaPublicKey and eccPublicKey.

Can I just use the ecdsaPublicKey in ecc crypto instead of generating a new eccPub？