1 files changed, 33 insertions, 0 deletions
diff --git a/internal/contentenc/content.go b/internal/contentenc/content.go
index 5bac2a2..2298c5e 100644
--- a/internal/contentenc/content.go
+++ b/internal/contentenc/content.go
@@ -8,9 +8,42 @@ import (
 	"encoding/hex"
 	"errors"
 
+	"github.com/rfjakob/gocryptfs/internal/cryptocore"
 	"github.com/rfjakob/gocryptfs/internal/tlog"
 )
 
+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
+}
+
 // DecryptBlocks - Decrypt a number of blocks
 func (be *ContentEnc) DecryptBlocks(ciphertext []byte, firstBlockNo uint64, fileId []byte) ([]byte, error) {
 	cBuf := bytes.NewBuffer(ciphertext)