🔐 Crypto Module

🎯 Module Objectives

This module provides secure cryptographic utilities for:

• 🔑 Generating public–private key pairs
• 💾 Saving and loading keys to/from the filesystem
• ✍️ Signing messages with a private key
• ✅ Verifying signatures with a public key

All cryptographic operations are handled internally using Ed25519 keys.

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📁 File Structure

crypto/
├── config/
│   └── config.go             # Platform-specific key file paths
├── cryptoutils/
│   └── cryptoutils.go        # Cryptographic functions
├── go.mod                    # Go module definition
└── README.md                 # Project documentation

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⚙️ Key File Configuration

Key paths are determined dynamically at runtime based on the operating system:

• Windows: %APPDATA%\yourapp\keys\priv.key
• macOS: ~/Library/Application Support/yourapp/keys/priv.key
• Linux: ~/.config/yourapp/keys/priv.key
• Fallback: ./keys/priv.key

Public keys are stored in the same folder as pub.key.

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🔧 Functions

1. GenerateKeyPair() (ed25519.PublicKey, ed25519.PrivateKey, error)

• Role: Generate a new Ed25519 key pair and save both keys to disk
• Input: None
• Returns: ed25519.PublicKey, ed25519.PrivateKey, error

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2. LoadKeys() (ed25519.PublicKey, ed25519.PrivateKey, error)

• Role: Load keys from disk. If the private key is missing or invalid, generate a new key pair. If the public key is missing, regenerate it from the private key and store it
• Input: None
• Returns: public key, private key, error

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3. SignMessage(privateKey ed25519.PrivateKey, message string) (string, string, error)

• Role: Sign a message using a private key
• Input: private key, message
• Returns: public key (base64-encoded string), sign (base64-encoded string), error

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4. VerifySignature(publicKeyStr string, message string, signStr string) bool

• Role: Verify a message-signature pair using the public key
• Input: public key (base64-encoded string), message, sign (base64-encoded string)
• Returns: true, false

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