diff options
Diffstat (limited to 'src/pkg/crypto/des/cipher.go')
-rw-r--r-- | src/pkg/crypto/des/cipher.go | 69 |
1 files changed, 21 insertions, 48 deletions
diff --git a/src/pkg/crypto/des/cipher.go b/src/pkg/crypto/des/cipher.go index fc252c813..2f929ca7b 100644 --- a/src/pkg/crypto/des/cipher.go +++ b/src/pkg/crypto/des/cipher.go @@ -4,7 +4,10 @@ package des -import "strconv" +import ( + "crypto/cipher" + "strconv" +) // The DES block size in bytes. const BlockSize = 8 @@ -15,86 +18,56 @@ func (k KeySizeError) Error() string { return "crypto/des: invalid key size " + strconv.Itoa(int(k)) } -// Cipher is an instance of DES encryption. -type Cipher struct { +// desCipher is an instance of DES encryption. +type desCipher struct { subkeys [16]uint64 } -// NewCipher creates and returns a new Cipher. -func NewCipher(key []byte) (*Cipher, error) { +// NewCipher creates and returns a new cipher.Block. +func NewCipher(key []byte) (cipher.Block, error) { if len(key) != 8 { return nil, KeySizeError(len(key)) } - c := new(Cipher) + c := new(desCipher) c.generateSubkeys(key) return c, nil } -// BlockSize returns the DES block size, 8 bytes. -func (c *Cipher) BlockSize() int { return BlockSize } +func (c *desCipher) BlockSize() int { return BlockSize } -// Encrypts the 8-byte buffer src and stores the result in dst. -// Note that for amounts of data larger than a block, -// it is not safe to just call Encrypt on successive blocks; -// instead, use an encryption mode like CBC (see crypto/cipher/cbc.go). -func (c *Cipher) Encrypt(dst, src []byte) { encryptBlock(c.subkeys[:], dst, src) } +func (c *desCipher) Encrypt(dst, src []byte) { encryptBlock(c.subkeys[:], dst, src) } -// Decrypts the 8-byte buffer src and stores the result in dst. -func (c *Cipher) Decrypt(dst, src []byte) { decryptBlock(c.subkeys[:], dst, src) } +func (c *desCipher) Decrypt(dst, src []byte) { decryptBlock(c.subkeys[:], dst, src) } -// Reset zeros the key data, so that it will no longer -// appear in the process's memory. -func (c *Cipher) Reset() { - for i := 0; i < len(c.subkeys); i++ { - c.subkeys[i] = 0 - } -} - -// A TripleDESCipher is an instance of TripleDES encryption. -type TripleDESCipher struct { - cipher1, cipher2, cipher3 Cipher +// A tripleDESCipher is an instance of TripleDES encryption. +type tripleDESCipher struct { + cipher1, cipher2, cipher3 desCipher } -// NewCipher creates and returns a new Cipher. -func NewTripleDESCipher(key []byte) (*TripleDESCipher, error) { +// NewTripleDESCipher creates and returns a new cipher.Block. +func NewTripleDESCipher(key []byte) (cipher.Block, error) { if len(key) != 24 { return nil, KeySizeError(len(key)) } - c := new(TripleDESCipher) + c := new(tripleDESCipher) c.cipher1.generateSubkeys(key[:8]) c.cipher2.generateSubkeys(key[8:16]) c.cipher3.generateSubkeys(key[16:]) return c, nil } -// BlockSize returns the TripleDES block size, 8 bytes. -// It is necessary to satisfy the Block interface in the -// package "crypto/cipher". -func (c *TripleDESCipher) BlockSize() int { return BlockSize } +func (c *tripleDESCipher) BlockSize() int { return BlockSize } -// Encrypts the 8-byte buffer src and stores the result in dst. -// Note that for amounts of data larger than a block, -// it is not safe to just call Encrypt on successive blocks; -// instead, use an encryption mode like CBC (see crypto/cipher/cbc.go). -func (c *TripleDESCipher) Encrypt(dst, src []byte) { +func (c *tripleDESCipher) Encrypt(dst, src []byte) { c.cipher1.Encrypt(dst, src) c.cipher2.Decrypt(dst, dst) c.cipher3.Encrypt(dst, dst) } -// Decrypts the 8-byte buffer src and stores the result in dst. -func (c *TripleDESCipher) Decrypt(dst, src []byte) { +func (c *tripleDESCipher) Decrypt(dst, src []byte) { c.cipher3.Decrypt(dst, src) c.cipher2.Encrypt(dst, dst) c.cipher1.Decrypt(dst, dst) } - -// Reset zeros the key data, so that it will no longer -// appear in the process's memory. -func (c *TripleDESCipher) Reset() { - c.cipher1.Reset() - c.cipher2.Reset() - c.cipher3.Reset() -} |