Add BlockNoPlainOff() and BlockNoCipherOff() + test

Also, fix key, it is now []byte, not [16]byte

1 files changed, 10 insertions, 0 deletions

diff --git a/cryptfs/cryptfs_content.go b/cryptfs/cryptfs_content.go
index a903e02..ab5ec78 100644
--- a/cryptfs/cryptfs_content.go
+++ b/cryptfs/cryptfs_content.go
@@ -219,3 +219,13 @@ func (be *CryptFS) MergeBlocks(oldData []byte, newData []byte, offset int) []byt
 	}
 	return out[0:outLen]
 }
+
+// Get the block number at plain-text offset
+func (be *CryptFS) BlockNoPlainOff(plainOffset uint64) uint64 {
+		return plainOffset / be.plainBS
+}
+
+// Get the block number at ciphter-text offset
+func (be *CryptFS) BlockNoCipherOff(cipherOffset uint64) uint64 {
+		return cipherOffset / be.cipherBS
+}