Go

Compress and Encrypt a Large File (Low and Constant Memory Footprint)

See more Compression Examples

Demonstrates how to compress and encrypt a large file such that the memory footprint remains low and constant.

Note: This example requires Chilkat v9.5.0.99 or greater.

Go

    success := false

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    compress := chilkat.NewCompression()
    compress.SetAlgorithm("deflate")

    // Set encryption params.
    // The possible values are the same as for the corresponding properties in the Chilkat Crypt2 class/object.
    // The encoded IV and Key must be specified as hex.
    json := chilkat.NewJsonObject()
    json.UpdateString("cryptAlgorithm","aes")
    json.UpdateString("cipherMode","cbc")
    json.UpdateInt("keyLength",128)
    json.UpdateInt("paddingScheme",0)
    json.UpdateString("encodedIV","000102030405060708090A0B0C0D0E0F")
    json.UpdateString("encodedKey","000102030405060708090A0B0C0D0E0F")

    // Do file-to-file compression+encryption in a single call.
    inPath := "qa_data/largeFile.dat"
    outPath := "c:/temp/qa_output/compressed_encrypted.dat"
    success = compress.CompressEncryptFile(json,inPath,outPath)
    if success == false {
        fmt.Println(compress.LastErrorText())
        compress.DisposeCompression()
        json.DisposeJsonObject()
        return
    }

    // We can do file-to-file decrypt/decompress like this:
    inPath2 := outPath
    outPath2 := "c:/temp/qa_output/restored.dat"
    success = compress.DecryptDecompressFile(json,inPath2,outPath2)
    if success == false {
        fmt.Println(compress.LastErrorText())
        compress.DisposeCompression()
        json.DisposeJsonObject()
        return
    }

    // Note: The above decrypt + decompress is the equivalent of doing the same in these two steps:
    crypt := chilkat.NewCrypt2()
    crypt.SetCryptAlgorithm("aes")
    crypt.SetCipherMode("cbc")
    crypt.SetKeyLength(128)
    crypt.SetPaddingScheme(0)
    crypt.SetEncodedIV("000102030405060708090A0B0C0D0E0F","hex")
    crypt.SetEncodedKey("000102030405060708090A0B0C0D0E0F","hex")

    decryptedPath := "c:/temp/qa_output/decrypted.dat"
    success = crypt.CkDecryptFile(inPath2,decryptedPath)
    if success == false {
        fmt.Println(crypt.LastErrorText())
        compress.DisposeCompression()
        json.DisposeJsonObject()
        crypt.DisposeCrypt2()
        return
    }

    outPath3 := "c:/temp/qa_output/restored_in_two_steps.dat"
    success = compress.DecompressFile(decryptedPath,outPath3)
    if success == false {
        fmt.Println(compress.LastErrorText())
        compress.DisposeCompression()
        json.DisposeJsonObject()
        crypt.DisposeCrypt2()
        return
    }

    fmt.Println("Success.")

    compress.DisposeCompression()
    json.DisposeJsonObject()
    crypt.DisposeCrypt2()