SHA256Gen-C

Simple SHA-256 hash generator written in C using OpenSSL.

Description

This program generates SHA-256 hashes for either input strings or files. It uses the OpenSSL library to perform the hashing operations and supports command-line arguments for ease of use.

Features

• Generate SHA-256 hashes for text strings.
• Generate SHA-256 hashes for files.
• Simple command-line interface.
• Error handling for invalid inputs and file operations.

Requirements

• C compiler (e.g., gcc)
• OpenSSL library (libcrypto)

Installation

1. Clone the repository:

   git clone https://github.com/3sus/sha256gen-c.git
   cd sha256gen-c

2. Compile the program with OpenSSL:

   gcc -o sha256gen sha256gen.c -lcrypto

   Ensure the OpenSSL development libraries are installed. On Debian-based systems, you can install them with:

   sudo apt-get install libssl-dev

   On Red Hat-based systems:

   sudo dnf install openssl-devel

Usage

Run the program from the command line with one of the following formats:

• Hash a string:

  ./sha256gen "your_string_here"

  Example:

  ./sha256gen "Hello, World!"

  Output:

  SHA-256 hash: a591a6d40bf420404a011733cfb7b190d62c65bf0bcda32b57b277d9ad9f146e
  

• Hash a file:

  ./sha256gen -f filename

  Example:

  ./sha256gen -f example.txt

  Output:

  SHA-256 hash of file 'example.txt': <hash_value>
  

Error Handling

• If no arguments are provided, the program displays usage instructions.
• If an empty string or filename is provided, an error message is shown.
• File operations include checks for file existence and read errors.
• Memory allocation failures are handled gracefully.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Contributing

Contributions are welcome! Please submit a pull request or open an issue on the GitHub repository.

Author

• 3sus (c) 2025