3. EasyPQC.FileOperations

NOTE: The serious UnpackFile bug is fixed — a wrong password (or a tampered/corrupt file) used to crash the unpack; now it fails cleanly and returns false. Pack/unpack round-trips work. One rough edge still to smooth out: the unpacked file comes out named after the internal packed name, so it currently loses the original filename/extension — rename it on your end if that matters.

Types

PackedFile

Represents a file that has been packed (compressed and optionally encrypted) with its associated signature.

  • Fields:

    • string FilePath: The path of the packed file.
    • string Signature: The signature of the packed file, usually encrypted.

  • Methods:

    • ToString(): Converts the PackedFile to a string representation in the format FilePath|Signature.
    • static PackedFile FromString(string packedFileString): Creates a PackedFile instance from a string representation.

CompressionLevel

Defines the level of compression for LZ4 compression.

  • Values:
    • Fast: Fast compression.
    • Balanced: Balanced compression.
    • Max: Maximum compression.

CompressionProgress

Delegate for reporting the progress of a file compression or decompression operation.

  • Parameters:
    • long current: The current position of the operation.
    • long fileSize: The total size of the file.
    • int percentage: The percentage of completion.

Methods

CompressFileAsync(string fileInput, string fileOutput, CompressionProgress compressionProgress, CompressionLevel compressionType)

Compresses a file asynchronously using LZ4 and reports progress.

  • Parameters:

    • fileInput: The input file path.
    • fileOutput: The output file path.
    • compressionProgress: A delegate for progress reporting.
    • compressionType: The level of compression to use.

  • Returns: Task: The path to the compressed file.

DecompressFileAsync(string fileInput, string fileOutput, CompressionProgress compressionProgress, CompressionLevel compressionType)

Decompresses a file asynchronously using LZ4 and reports progress.

  • Parameters:

    • fileInput: The input file path.
    • fileOutput: The output file path.
    • compressionProgress: A delegate for progress reporting.
    • compressionType: The level of compression to use.

  • Returns: Task: The path to the decompressed file.

HashFile(Stream fileData)

Hashes a file asynchronously using Blake3.

  • Parameters:

    • fileData: The stream containing the file data to hash.

  • Returns: Task<byte[]>: The computed hash of the file.

VerifyHash(Stream fileData, byte[] signature)

Verifies the integrity of a file by comparing its hash to a provided signature.

  • Parameters:

    • fileData: The stream containing the file data to verify.
    • signature: The signature to compare the hash against.

  • Returns: Task: true if the hash matches the signature, otherwise false.

PackFiles(string fileInput, string fileOutput, Dictionary<string, byte[]> privateKey, SecureData sessionkey, CompressionProgress compressionProgress, CompressionLevel compressionType, bool encryptFile)

Compresses a file, creates a signed hash, and optionally encrypts the file.

  • Parameters:

    • fileInput: The input file path.
    • fileOutput: The output directory for the packed file.
    • privateKey: The private key for signing the file hash.
    • sessionkey: The session key for encryption (if applicable).
    • compressionProgress: A delegate for progress reporting.
    • compressionType: The level of compression to use.
    • encryptFile: Whether to encrypt the packed file.

  • Returns: Task: A PackedFile containing the packed file and its signature.

UnpackFile(PackedFile inputFile, string outputPath, Dictionary<string, byte[]> publicKey, CompressionProgress compressionProgress, CompressionLevel compressionType, SecureData sessionkey)

Unpacks and decompresses a file, verifying its signature and decrypting it if necessary. A wrong password, a bad signature, or a tampered/corrupt file returns false instead of throwing.

  • Parameters:

    • inputFile: The packed file to unpack.
    • outputPath: The directory where the unpacked file should be saved.
    • publicKey: The public key for signature verification.
    • compressionProgress: A delegate for progress reporting.
    • compressionType: The level of compression used.
    • sessionkey: The session key for decryption (if applicable).

  • Returns: Task: true if the file was successfully unpacked and verified, otherwise false.