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Fully functional encrypt/decrypt

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This commit is contained in:
Dan Flack 2024-09-20 21:00:05 +02:00
parent 743d6da32c
commit 0a7b4440db
2 changed files with 31 additions and 13 deletions
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41
src/core/lib/SM2.mjs
View file

@ -5,6 +5,7 @@
* @license Apache-2.0
*/
import OperationError from "../errors/OperationError.mjs";
import { fromHex } from "../lib/Hex.mjs";
import Utils from "../Utils.mjs";
import Sm3 from "crypto-api/src/hasher/sm3.mjs";
@ -42,7 +43,6 @@ export class SM2 {
* @param {string} publicKeyY
*/
setPublicKey(publicKeyX, publicKeyY) {
console.log('Set public key')
/*
* TODO: This needs some additional length validation; and checking for errors in the decoding process
* TODO: Can probably support other public key encoding methods here as well in the future
@ -59,8 +59,8 @@ export class SM2 {
*
* @param {string} privateKey
*/
setPrivateKey(privateKey) {
this.privateKey = null; //Somehow take hex input and translate back to a BigInteger???
setPrivateKey(privateKeyHex) {
this.privateKey = new r.BigInteger(privateKeyHex, 16);
}
/**
@ -115,10 +115,21 @@ export class SM2 {
* @param {*} input
*/
decrypt(input) {
/*
*
*/
var c1 = this.ecParams.curve.decodePointHex("04" + publicKeyX + publicKeyY);
var c1X = input.slice(0, 64);
var c1Y = input.slice(64, 128);
var c3 = ""
var c2 = ""
if (this.format == "C1C3C2") {
c3 = input.slice(128,192);
c2 = input.slice(192);
} else {
c2 = input.slice(128, -64);
c3 = input.slice(-64);
}
c2 = Uint8Array.from(fromHex(c2))
var c1 = this.ecParams.curve.decodePointHex("04" + c1X + c1Y);
/*
* Compute the p2 (secret) value by taking the C1 point provided in the encrypted package, and multiplying by the private k value
@ -128,12 +139,18 @@ export class SM2 {
/*
* Similar to encryption; compute sufficient length key material and XOR the input data to recover the original message
*/
var key = this.kdf(p2, input.byteLength);
for (let i = 0; i < input.byteLength; i++) {
input[i] ^= Utils.ord(key[i]);
var key = this.kdf(p2, c2.byteLength);
for (let i = 0; i < c2.byteLength; i++) {
c2[i] ^= Utils.ord(key[i]);
}
var check = this.c3(p2, c2);
if (check === c3) {
return c2.buffer;
} else {
throw new OperationError("Decryption Error -- Computed Hashes Do Not Match");
}
console.log(input)
//var dec = Buffer.from(input).toString('hex');
}

3
src/core/operations/SM2Decrypt.mjs
View file

@ -56,7 +56,8 @@ class SM2Decrypt extends Operation {
var sm2 = new SM2(curveName, inputFormat);
sm2.setPrivateKey(privateKey);
var result = sm2.decrypt(new Uint8Array(input))
var result = sm2.decrypt(input);
return result
}