Cryptography package for message auto encrypt

Info

The provided Go code demonstrates a function named ConvertToKeys in a struct named Keys. It takes an input key (slice of bytes) and generates keys suitable for use with AES-256 encryption and a nonce for AES GCM mode. It's not a complete implementation though as it references k.generateFromKey(inputKey) which is presumably defined elsewhere as a method on the Keys struct. Here's a breakdown of what the function is doing: It checks if the inputKey provided has a length less than 2. If so, it returns nil, nil, and an error message indicating that the input key is too short. This would be a precondition requirement of the k.generateFromKey(inputKey) which is not shown here. After verifying the length of the input key, the generateFromKey method is called on the Keys struct to generate a selectedKey. It's likely that this function transforms or derives a new key from the input key. Then, some variables are created: A slice, matrixKey, of the needed size is made, which is 354 bits or (k.length) bytes long. key and nonce slices are made to hold the final 256-bit AES key and 96-bit GCM nonce respectively. The next step involves iterating through each byte in selectedKey and using a XOR operation to manipulate the key at a byte level with the inputKey. This operation is done to ensure the final key and nonce are derived in a cryptographically sound way. The final key and nonce are obtained by slicing the first 32 bytes and the next 12 bytes from the matrixKey respectively. Finally, the key, nonce and nil as error are returned from the function.