Privhat

    ____  ____  _____    __   __  _____  ______
   / __ \/ __ \/  _/ |  / /  / / / /   |/_  __/
  / /_/ / /_/ // / | | / /  / /_/ / /| | / /   
 / ____/ _, _// /  | |/ /  / __  / ___ |/ /    
/_/   /_/ |_/___/  |___/  /_/ /_/_/  |_/_/     
                                               

Privhat is a lightweight command-line cryptography tool written in Python that supports key user management, encryption, decryption, signing, and signature verification with multiple algorithms like RSA, ECC, and ElGamal. All cryptographic functions are self-implemented for educational purposes, providing hands-on insight into the underlying algorithms and processes.

Note: Privhat is a lightweight, educational tool with self-implemented cryptographic algorithms and is not intended for securing real-world sensitive data. It lacks the rigorous security audits and protections of established cryptographic libraries. For actual privacy and security needs, please rely on well-vetted tools created by experts so paranoid and skilled that the feds occasionally show up at their door — like OpenGPG or other widely trusted cryptographic software.

---

🖼️ Screenshot

Here’s a glimpse of PRIVHAT:

---

Features

• Create and delete users with keypairs (RSA, ECC, ElGamal)
• Import public keys from JSON files or directly via parameters
• Encrypt messages/files using user public keys or direct keys
• Decrypt messages/files using private keys
• Sign messages and verify signatures (planned features)
• Clean CLI interface with intuitive commands
• Organized storage for keys, messages, and users
• Easily ignore sensitive ciphertext and plaintext files in .gitignore

---

Installation

1. Clone this repository:

git clone https://github.com/ayiman29/privhat.git
cd privhat

2. (Optional) Create and activate a Python virtual environment:

python -m venv venv
source venv/bin/activate   # Linux/macOS
venv\Scripts\activate      # Windows

3. Install dependencies:

pip install -r requirements.txt

---

🛠️ Usage

Run the CLI tool using Python:

python privhat.py [command] [options]

📋 Commands

👤 Create User

Create a new user and generate a key pair:

python privhat.py create-user <username> --alg rsa|ecc|elgamal

❌ Delete User

Delete an existing user and their stored keys:

python privhat.py delete-user <username>

📥 Import Public Key

Import an RSA public key manually:

python privhat.py import-pubkey <username> --e <int> --n <int>

📜 List Users

List all registered users and their key status (local or imported):

python privhat.py list-users

---

🔐 Encrypt

python privhat.py encrypt [OPTIONS]

Options:

Option	Description
--to <username>	Encrypt using a registered user's public key
--pubkey-file <path>	Encrypt using a public key file (JSON)
--text <string>	Plaintext input to encrypt
--in <file>	Input plaintext file
--out <file>	Output ciphertext file
--pubkey-e <value> --pubkey-n <value>	Encrypt using raw RSA public key components
--alg <rsa | ecc | elgamal>	Algorithm to use

✅ Encrypt Examples

1. Encrypt Text to a User (stored public key)

python privhat.py encrypt --to alice --text "Hello Alice" --out hello.enc --alg rsa

2. Encrypt a File to a User

python privhat.py encrypt --to alice --in notes.txt --out notes.enc --alg rsa

3. Encrypt Text with a Public Key File

python privhat.py encrypt --pubkey-file keys/bob_pubkey.json --text "Secret message" --out msg.enc --alg rsa

4. Encrypt File with a Public Key File

python privhat.py encrypt --pubkey-file keys/bob_pubkey.json --in doc.txt --out doc.enc --alg rsa

5. Encrypt Text and Output to Stdout

python privhat.py encrypt --to alice --text "Just display this" --alg rsa

6. Encrypt Text Using Raw Public Key Components

python privhat.py encrypt --pubkey-e 65537 --pubkey-n 123456789123456789123456789 --text "Hello from raw key" --out out.enc --alg rsa

---

🔓 Decrypt

python privhat.py decrypt [OPTIONS]

Options:

Option	Description
--user <username>	Registered user to use for decryption
--in <file>	Encrypted file input
--cipher <string>	Encrypted ciphertext string (Base64 or hex)
--out <file>	Output plaintext file

✅ Decrypt Examples

1. Decrypt File and Save Output

python privhat.py decrypt --user alice --in hello.enc --out hello.txt

2. Decrypt Ciphertext Hex String

python privhat.py decrypt --user iloveglass2 --cipher "12345...."

---

🔁 Summary Matrix

Use Case	Encrypt Command	Decrypt Command
Encrypt text to user	--to <user> --text <text>	--user <user> --cipher <hex>
Encrypt file to user	--to <user> --in <file>	--user <user> --in <file>
Encrypt text with key file	--pubkey-file <file> --text <text>	N/A
Encrypt file with key file	--pubkey-file <file> --in <file>	N/A
Decrypt file to stdout	N/A	--user <user> --in <file>
Decrypt ciphertext string to stdout	N/A	--user <user> --cipher <hex>
Decrypt ciphertext string to file	N/A	--user <user> --cipher <hex> --out <file>

---

✍️ Sign

python privhat.py sign [OPTIONS]

Options:

Option	Description
--user <username>	Username whose private key will be used to sign
--in <file>	File containing message to sign
--text <string>	Plaintext message to sign directly
--out <file>	Output file to save the signature (optional)
--alg <rsa | ecdsa>	Algorithm to use for signing (rsa or ecdsa)

✅ Sign Examples

1. Sign Text Message and Save Signature

python privhat.py sign --user alice --text "This is a signed message." --out sig.txt --alg rsa

2. Sign File and Save Signature

python privhat.py sign --user bob --in important.txt --out important.sig --alg rsa

3. Sign Text Message and Output to Stdout

python privhat.py sign --user alice --text "Ephemeral signature" --alg rsa

---

✅ Verify

python privhat.py verify [OPTIONS]

Options:

Option	Description
--from <username>	Username whose public key will be used for verification
--in <file>	Input file containing the original message
--text <string>	Message to verify directly as string
--sig <file>	Signature file path
--cipher <string>	Signature directly as string (e.g. from stdout)
--alg <rsa | ecdsa>	Algorithm used for signature (rsa or ecdsa)

✅ Verify Examples

1. Verify Text and Signature File

python privhat.py verify --from alice --text "This is a signed message." --sig sig.txt --alg rsa

2. Verify File and Signature File

python privhat.py verify --from bob --in important.txt --sig important.sig --alg rsa

3. Verify Text and Signature String

python privhat.py verify --from alice --text "Hello world" --cipher "abc123def456..." --alg rsa

4. Verify File with Inline Signature String

python privhat.py verify --from bob --in statement.txt --cipher "abcd1234..." --alg rsa

---

🔁 Summary Matrix

Use Case	Sign Command	Verify Command
Sign text to stdout	--text <string>	N/A
Sign text and save to file	--text <string> --out <file>	--text <string> --sig <file> or --cipher <string>
Sign file and save to file	--in <file> --out <file>	--in <file> --sig <file> or --cipher <string>
Verify text with signature	N/A	--text <string> --sig <file> or --cipher <string>
Verify file with signature	N/A	--in <file> --sig <file> or --cipher <string>

---

Directory Structure

privhat/
│
├── privhat.py                  # Main CLI entry point
├── crypto_engine.py        # Core crypto operations
├── user_manager.py         # User and key management
├── storage/
│   ├── users.json          # Registered users
│   ├── keys/               # Private/public keys
│   └── messages/           # Ciphertext/plaintext files (add to .gitignore)
├── requirements.txt
└── README.md

---

Notes

• Current implementation supports RSA fully; ECC and ElGamal are in progress.

---