diff options
Diffstat (limited to 'cryptfs/intrablock.go')
-rw-r--r-- | cryptfs/intrablock.go | 51 |
1 files changed, 0 insertions, 51 deletions
diff --git a/cryptfs/intrablock.go b/cryptfs/intrablock.go deleted file mode 100644 index faff471..0000000 --- a/cryptfs/intrablock.go +++ /dev/null @@ -1,51 +0,0 @@ -package cryptfs - -// intraBlock identifies a part of a file block -type intraBlock struct { - BlockNo uint64 // Block number in file - Skip uint64 // Offset into block plaintext - Length uint64 // Length of data from this block - fs *CryptFS -} - -// isPartial - is the block partial? This means we have to do read-modify-write. -func (ib *intraBlock) IsPartial() bool { - if ib.Skip > 0 || ib.Length < ib.fs.plainBS { - return true - } - return false -} - -// CiphertextRange - get byte range in ciphertext file corresponding to BlockNo -// (complete block) -func (ib *intraBlock) CiphertextRange() (offset uint64, length uint64) { - return ib.fs.BlockNoToCipherOff(ib.BlockNo), ib.fs.cipherBS -} - -// PlaintextRange - get byte range in plaintext corresponding to BlockNo -// (complete block) -func (ib *intraBlock) PlaintextRange() (offset uint64, length uint64) { - return ib.fs.BlockNoToPlainOff(ib.BlockNo), ib.fs.plainBS -} - -// CropBlock - crop a potentially larger plaintext block down to the relevant part -func (ib *intraBlock) CropBlock(d []byte) []byte { - lenHave := len(d) - lenWant := int(ib.Skip + ib.Length) - if lenHave < lenWant { - return d[ib.Skip:lenHave] - } - return d[ib.Skip:lenWant] -} - -// Ciphertext range corresponding to the sum of all "blocks" (complete blocks) -func (ib *intraBlock) JointCiphertextRange(blocks []intraBlock) (offset uint64, length uint64) { - firstBlock := blocks[0] - lastBlock := blocks[len(blocks)-1] - - offset = ib.fs.BlockNoToCipherOff(firstBlock.BlockNo) - offsetLast := ib.fs.BlockNoToCipherOff(lastBlock.BlockNo) - length = offsetLast + ib.fs.cipherBS - offset - - return offset, length -} |