cotiv2-mcp/build/PrivateAES.js

> A plug-and-play MCP tool server to **send COTI**, **transfer BEP-20 tokens**, **deploy tokens**, and **interact with smart contracts** on the **COTI v2 Network (COTI)** — built for **Claude Desktop**, **AI agents**, and **developers.**

import * as crypto from "crypto";
import * as bcrypt from "bcrypt";
const algorithm = "aes-256-gcm";
/**
 * Encrypts an EVM private key using bcrypt and user password
 * @param privateKey The EVM private key to encrypt
 * @param password User-provided password
 * @returns Encrypted string (Base64 encoded)
 */
export async function encryptPrivateKey(privateKey, password) {
    // bcrypt work factor - higher is more secure but slower
    const saltRounds = 12;
    // Generate bcrypt hash as key material
    const hashedPassword = await bcrypt.hash(password, saltRounds);
    // Extract bcrypt salt - it's in the first 29 characters of the hash
    const bcryptSalt = hashedPassword.substring(0, 29);
    // Generate symmetric encryption key using SHA-256 from bcrypt hash
    const key = crypto.createHash("sha256").update(hashedPassword).digest();
    // Generate random initialization vector
    const iv = crypto.randomBytes(12);
    // Create cipher object
    const cipher = crypto.createCipheriv(algorithm, key, iv);
    // Encrypt private key
    let encrypted = cipher.update(privateKey, "utf8", "base64");
    encrypted += cipher.final("base64");
    // Get authentication tag
    const authTag = cipher.getAuthTag();
    // Concatenate all necessary components and encode as Base64 string
    const result = Buffer.concat([
        Buffer.from(bcryptSalt), // Store bcrypt salt
        iv,
        authTag,
        Buffer.from(encrypted, "base64"),
    ]);
    return result.toString("base64");
}
/**
 * Decrypts an EVM private key using bcrypt and user password
 * @param encryptedData Encrypted private key data (Base64 encoded)
 * @param password User-provided password
 * @returns Decrypted private key or null (if password is incorrect)
 */
export async function decryptPrivateKey(encryptedData, password) {
    try {
        // Decode Base64
        const data = Buffer.from(encryptedData, "base64");
        // Extract components
        const bcryptSalt = data.subarray(0, 29).toString();
        const iv = data.subarray(29, 41);
        const authTag = data.subarray(41, 57);
        const encrypted = data.subarray(57).toString("base64");
        // Use bcrypt to check password
        // Reconstruct salt and password to create the same hash as during encryption
        const hashedPassword = await bcrypt.hash(password, bcryptSalt);
        // Generate key using the same method from the hash
        const key = crypto.createHash("sha256").update(hashedPassword).digest();
        // Create decipher
        const decipher = crypto.createDecipheriv(algorithm, key, iv);
        decipher.setAuthTag(authTag);
        // Decrypt
        let decrypted = decipher.update(encrypted, "base64", "utf8");
        decrypted += decipher.final("utf8");
        return decrypted;
    }
    catch (error) {
        // Decryption failed (incorrect password or data corruption)
        return null;
    }
}