libgocryptfs/internal/contentenc/content_api.go

package contentenc

import "github.com/rfjakob/gocryptfs/internal/cryptocore"

const (
	// Default plaintext block size
	DefaultBS = 4096
)

type ContentEnc struct {
	// Cryptographic primitives
	cryptoCore *cryptocore.CryptoCore
	// Plaintext block size
	plainBS uint64
	// Ciphertext block size
	cipherBS uint64
	// All-zero block of size cipherBS, for fast compares
	allZeroBlock []byte
}

func New(cc *cryptocore.CryptoCore, plainBS uint64) *ContentEnc {

	cipherBS := plainBS + uint64(cc.IVLen) + cryptocore.AuthTagLen

	return &ContentEnc{
		cryptoCore:   cc,
		plainBS:      plainBS,
		cipherBS:     cipherBS,
		allZeroBlock: make([]byte, cipherBS),
	}
}

func (be *ContentEnc) PlainBS() uint64 {
	return be.plainBS
}