Documentation

Overview

    Package xts implements the XTS cipher mode as specified in IEEE P1619/D16.

    XTS mode is typically used for disk encryption, which presents a number of novel problems that make more common modes inapplicable. The disk is conceptually an array of sectors and we must be able to encrypt and decrypt a sector in isolation. However, an attacker must not be able to transpose two sectors of plaintext by transposing their ciphertext.

    XTS wraps a block cipher with Rogaway's XEX mode in order to build a tweakable block cipher. This allows each sector to have a unique tweak and effectively create a unique key for each sector.

    XTS does not provide any authentication. An attacker can manipulate the ciphertext and randomise a block (16 bytes) of the plaintext. This package does not implement ciphertext-stealing so sectors must be a multiple of 16 bytes.

    Note that XTS is usually not appropriate for any use besides disk encryption. Most users should use an AEAD mode like GCM (from crypto/cipher.NewGCM) instead.

    Index

    Constants

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    Variables

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    Functions

    This section is empty.

    Types

    type Cipher

    type Cipher struct {
    	// contains filtered or unexported fields
    }

      Cipher contains an expanded key structure. It is safe for concurrent use if the underlying block cipher is safe for concurrent use.

      func NewCipher

      func NewCipher(cipherFunc func([]byte) (cipher.Block, error), key []byte) (c *Cipher, err error)

        NewCipher creates a Cipher given a function for creating the underlying block cipher (which must have a block size of 16 bytes). The key must be twice the length of the underlying cipher's key.

        func (*Cipher) Decrypt

        func (c *Cipher) Decrypt(plaintext, ciphertext []byte, sectorNum uint64)

          Decrypt decrypts a sector of ciphertext and puts the result into plaintext. Plaintext and ciphertext must overlap entirely or not at all. Sectors must be a multiple of 16 bytes and less than 2²⁴ bytes.

          func (*Cipher) Encrypt

          func (c *Cipher) Encrypt(ciphertext, plaintext []byte, sectorNum uint64)

            Encrypt encrypts a sector of plaintext and puts the result into ciphertext. Plaintext and ciphertext must overlap entirely or not at all. Sectors must be a multiple of 16 bytes and less than 2²⁴ bytes.

            Source Files