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.gitignore

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+node_modules/

README.md

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+# @nilajs/digital-signature
+
+A digital signature is a cryptographic mechanism used to verify the authenticity and integrity of digital messages or documents. It provides assurances that the message was indeed created by a particular entity (authentication) and that the message has not been altered or tampered with since it was signed (integrity).
+
+A simple library for generating elliptic curve (secp256k1) key pairs, signing data, verifying signatures, and validating public keys. 
+
+## Installation
+
+You can install the package via npm:
+
+```sh
+npm install @nilajs/digital-signature
+```
+
+## Usage
+
+### Import the Library
+
+```javascript
+const {
+  generateWallet,
+  checkPublicKeyValid,
+  signData,
+  verifySignature
+} = require('@nilajs/digital-signature');
+```
+
+### Generate Wallet
+
+Generate a new wallet (elliptic curve (secp256k1) key pair) :
+
+```javascript
+const { publicKey, privateKey } = generateWallet();
+console.log(`Public Key: ${publicKey}`);
+console.log(`Private Key: ${privateKey}`);
+```
+
+### Validate Public Key
+
+Check if a given public key is valid:
+
+```javascript
+const publicKey = 'YOUR_PUBLIC_KEY';
+const result = checkPublicKeyValid(publicKey);
+console.log(result); // { valid: true/false, public_key: 'YOUR_PUBLIC_KEY' }
+```
+
+### Sign Data
+
+Sign a piece of data with a private key:
+
+```javascript
+const privateKey = 'YOUR_PRIVATE_KEY';
+const data = 'This is the data to be signed';
+const signatureObject = signData(privateKey, data);
+console.log(signatureObject);
+/*
+{
+  data: 'This is the data to be signed',
+  signature: {
+    r: 'SIGNATURE_R',
+    s: 'SIGNATURE_S'
+  }
+}
+*/
+```
+
+### Verify Signature
+
+Verify the signature of the data with a public key:
+
+```javascript
+const publicKey = 'YOUR_PUBLIC_KEY';
+const data = 'This is the data to be signed';
+const signature = {
+  r: 'SIGNATURE_R',
+  s: 'SIGNATURE_S'
+};
+const verificationResult = verifySignature(publicKey, data, signature);
+console.log(verificationResult);
+/*
+{
+  data: 'This is the data to be signed',
+  signature: {
+    r: 'SIGNATURE_R',
+    s: 'SIGNATURE_S'
+  },
+  is_verified: true/false
+}
+*/
+```
+
+## API Reference
+
+### `generateWallet()`
+
+Generates a new elliptic curve (secp256k1) key pair.
+
+**Returns:**
+- `Object`: An object containing the `publicKey` and `privateKey` as hexadecimal strings.
+
+### `checkPublicKeyValid(publicKey)`
+
+Checks if a given public key is valid.
+
+**Parameters:**
+- `publicKey` (`string`): The public key to validate.
+
+**Returns:**
+- `Object`: An object containing:
+  - `valid` (`boolean`): Whether the public key is valid.
+  - `public_key` (`string`): The provided public key.
+
+### `signData(privateKey, data)`
+
+Signs a piece of data with a private key.
+
+**Parameters:**
+- `privateKey` (`string`): The private key to sign with.
+- `data` (`string`): The data to sign.
+
+**Returns:**
+- `Object`: An object containing the signed `data` and `signature` (with `r` and `s` as hexadecimal strings).
+
+### `verifySignature(publicKey, data, signature)`
+
+Verifies the signature of the data with a public key.
+
+**Parameters:**
+- `publicKey` (`string`): The public key to verify with.
+- `data` (`string`): The signed data.
+- `signature` (`Object`): The signature object containing `r` and `s` as hexadecimal strings.
+
+**Returns:**
+- `Object`: An object containing:
+  - `data` (`string`): The signed data.
+  - `signature` (`Object`): The signature object.
+  - `is_verified` (`boolean`): Whether the signature is valid.
+
+## License
+
+MIT
+```
+
+### Summary
+
+This `README.md` provides an overview of the functions in your `@nilajs/digital-signature` package, along with installation instructions, usage examples, and an API reference. This documentation will help users understand how to use your package effectively.

index.js

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+/*
+Copyright sivabharathy.in All Rights Reserved.
+*/
+const crypto = require('crypto');
+const { randomBytes } = require('crypto');
+const { ec } = require('elliptic');
+const EC = new ec('secp256k1');
+/**
+ * 
+ * @returns 
+ */
+function generateWallet() {
+  const privateKey = randomBytes(32).toString('hex');
+  const keyPair = EC.keyFromPrivate(privateKey);
+  const publicKey = keyPair.getPublic('hex');
+  return { publicKey, privateKey };
+}
+/**
+ * 
+ * @param {*} publicKey 
+ * @returns Boolean
+ */
+function checkPublicKeyValid(publicKey) {
+  try {
+    // Attempt to create a keyPair from the provided public key
+    const keyPair = EC.keyFromPublic(publicKey, 'hex');
+    // Validate the key by getting its public key and comparing
+    const isValid = keyPair.getPublic('hex') === publicKey;
+    return { valid: isValid, public_key: publicKey }
+  } catch (error) {
+    // If an error occurs, the public key is invalid
+    return { valid: false, public_key: publicKey }
+  }
+}
+/**
+ * 
+ * @param {*} privateKey 
+ * @param {*} data 
+ * @returns Object
+ */
+function signData(privateKey, data) {
+  const keyPair = EC.keyFromPrivate(privateKey);
+  const msgHash = crypto.createHash('sha256').update(data).digest();
+  const signature = keyPair.sign(msgHash);
+  // return signature with data signed
+  return {
+    data,
+    signature: {
+        r: signature.r.toString('hex'),
+        s: signature.s.toString('hex')
+    }
+  }
+}
+/**
+ * 
+ * @param {*} publicKey 
+ * @param {*} data 
+ * @param {*} signature 
+ * @returns 
+ */
+function verifySignature(publicKey, data, signature) {
+  const keyPair = EC.keyFromPublic(publicKey, 'hex');
+  const msgHash = crypto.createHash('sha256').update(data).digest();
+
+  const isVerified = keyPair.verify(msgHash, {
+      r: signature.r,
+      s: signature.s
+  });
+
+  return {
+    data,
+    signature,
+    is_verified: isVerified
+  }
+}
+module.exports = {
+  generateWallet,
+  checkPublicKeyValid,
+  signData,
+  verifySignature
+}

package.json

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+{
+  "name": "@nilajs/digital-signature",
+  "version": "1.0.0",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": ["blockchain", "digital signature"],
+  "author": "sivabharathy <[email protected]>",
+  "license": "MIT",
+  "description": "",
+  "dependencies": {
+    "elliptic": "^6.5.5"
+  }
+}