contcrypter

Documentation

Index

• Constants
• type ContentCrypter
  • func NewContentCrypter(core corecrypter.CoreCrypter, plainBS int) *ContentCrypter
  • func (cc *ContentCrypter) BlockNoToCipherOff(blockNo uint64) uint64
  • func (cc *ContentCrypter) BlockNoToPlainOff(blockNo uint64) uint64
  • func (cc *ContentCrypter) BlockOverhead() uint64
  • func (cc *ContentCrypter) CipherBS() int
  • func (cc *ContentCrypter) CipherOffToBlockNo(cipherOffset uint64) uint64
  • func (cc *ContentCrypter) CipherSizeToPlainSize(cipherSize uint64) uint64
  • func (cc *ContentCrypter) DecryptBlocks(cipher []byte, firstBlockNo uint64, fileID []byte) ([][]byte, error)
  • func (cc *ContentCrypter) EncryptBlocks(blocks [][]byte, firstBlockNo uint64, fileID []byte) ([]byte, error)
  • func (cc *ContentCrypter) ExplodePlainRange(offset uint64, length int) []IntraBlock
  • func (cc *ContentCrypter) MergeBlock(oldData []byte, newData []byte, offset int) []byte
  • func (cc *ContentCrypter) PlainBS() int
  • func (cc *ContentCrypter) PlainOffToBlockNo(plainOffset uint64) uint64
  • func (cc *ContentCrypter) PlainSizeToCipherSize(plainSize uint64) uint64
  • func (cc *ContentCrypter) RewriteBlock(oldData []byte, newData []byte, offset int) []byte
  • func (cc *ContentCrypter) TransformPlainRange(offset uint64, length int) (plainSkip int, alignedOff uint64, alignedLen int)
• type FileHeader
  • func NewFileHeader(mode uint32) *FileHeader
  • func ParseHeader(buf []byte) (*FileHeader, error)
  • func (h *FileHeader) Pack() []byte
• type IntraBlock

Constants

const (
	// CurrentVersion is the current On-Disk-Format version
	CurrentVersion = 0

	// HeaderLen is the total header length
	HeaderLen = headerVersionLen + headerIDLen + headerPropertiesLen + headerSignLen
)

Types

type ContentCrypter

type ContentCrypter struct {

	// Plaintext block pool. Always returns plainBS-sized byte slices.
	PBlockPool bPool
	// Ciphertext request data pool. Always returns byte slices of size
	// fuse.MAX_KERNEL_WRITE + overhead.
	CReqPool bPool
	// Plaintext request data pool. Slice have size fuse.MAX_KERNEL_WRITE.
	PReqPool bPool
	// contains filtered or unexported fields
}

ContentCrypter encrypt and decrypt file content

func NewContentCrypter

func NewContentCrypter(core corecrypter.CoreCrypter, plainBS int) *ContentCrypter

NewContentCrypter initiate a ContentCrypter

func (*ContentCrypter) BlockNoToCipherOff

func (cc *ContentCrypter) BlockNoToCipherOff(blockNo uint64) uint64

BlockNoToCipherOff gets the ciphertext offset of block "blockNo"

func (*ContentCrypter) BlockNoToPlainOff

func (cc *ContentCrypter) BlockNoToPlainOff(blockNo uint64) uint64

BlockNoToPlainOff gets the plaintext offset of block "blockNo"

func (*ContentCrypter) BlockOverhead

func (cc *ContentCrypter) BlockOverhead() uint64

BlockOverhead returns the per-block overhead.

func (*ContentCrypter) CipherBS

func (cc *ContentCrypter) CipherBS() int

CipherBS return the cipher block size

func (*ContentCrypter) CipherOffToBlockNo

func (cc *ContentCrypter) CipherOffToBlockNo(cipherOffset uint64) uint64

CipherOffToBlockNo converts the ciphertext offset to the plaintext block numccr.

func (*ContentCrypter) CipherSizeToPlainSize

func (cc *ContentCrypter) CipherSizeToPlainSize(cipherSize uint64) uint64

CipherSizeToPlainSize calculates the plaintext size from a ciphertext size

func (*ContentCrypter) DecryptBlocks

func (cc *ContentCrypter) DecryptBlocks(cipher []byte, firstBlockNo uint64, fileID []byte) ([][]byte, error)

DecryptBlocks decrypt multiple continous cipher blocks

func (*ContentCrypter) EncryptBlocks

func (cc *ContentCrypter) EncryptBlocks(blocks [][]byte, firstBlockNo uint64, fileID []byte) ([]byte, error)

EncryptBlocks encrypt multiple continuous plain blocks

func (*ContentCrypter) ExplodePlainRange

func (cc *ContentCrypter) ExplodePlainRange(offset uint64, length int) []IntraBlock

ExplodePlainRange splits a plaintext byte range into (possibly partial) blocks Returns an empty slice if length == 0.

func (*ContentCrypter) MergeBlock

func (cc *ContentCrypter) MergeBlock(oldData []byte, newData []byte, offset int) []byte

MergeBlock - Merge newData into oldData at offset

func (*ContentCrypter) PlainBS

func (cc *ContentCrypter) PlainBS() int

PlainBS return the plain block size

func (*ContentCrypter) PlainOffToBlockNo

func (cc *ContentCrypter) PlainOffToBlockNo(plainOffset uint64) uint64

PlainOffToBlockNo converts a plaintext offset to the ciphertext block numccr.

func (*ContentCrypter) PlainSizeToCipherSize

func (cc *ContentCrypter) PlainSizeToCipherSize(plainSize uint64) uint64

PlainSizeToCipherSize calculates the ciphertext size from a plaintext size

func (*ContentCrypter) RewriteBlock

func (cc *ContentCrypter) RewriteBlock(oldData []byte, newData []byte, offset int) []byte

RewriteBlock - Merge newData into oldData at offset

Rewrite in place.

func (*ContentCrypter) TransformPlainRange

func (cc *ContentCrypter) TransformPlainRange(offset uint64, length int) (plainSkip int, alignedOff uint64, alignedLen int)

TransformPlainRange transform plain range to a cipher range for reading

plainSkip: offset to the block start
alignedOff: the first block start pos in ciphertext before the transformed range
alignedLen: cipher length to cover the transformed range

type FileHeader

type FileHeader struct {
	Version uint16
	FileID  []byte
	Mode    uint32
	// contains filtered or unexported fields
}

FileHeader represents the header stored on each non-empty file.

func NewFileHeader

func NewFileHeader(mode uint32) *FileHeader

NewFileHeader - create new fileHeader object with random Id

func ParseHeader

func ParseHeader(buf []byte) (*FileHeader, error)

ParseHeader - parse "buf" into fileHeader object

func (*FileHeader) Pack

func (h *FileHeader) Pack() []byte

Pack - sign and serialize fileHeader object

type IntraBlock

type IntraBlock struct {
	// BlockNo is the block numccr in the file
	BlockNo uint64
	// Skip is an offset into the block payload
	// In forwared mode: block plaintext
	// In reverse mode: offset into block ciphertext. Takes the header into
	// account.
	Skip int
	// Length of payload data in this block
	// In forwared mode: length of the plaintext
	// In reverse mode: length of the ciphertext. Takes header and trailer into
	// account.
	Length int
	// Partial - if this intra block is partial of a block
	Partial bool
}

IntraBlock identifies a part of a file block