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path: root/src/pkg/crypto/cipher/cfb.go
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Diffstat (limited to 'src/pkg/crypto/cipher/cfb.go')
-rw-r--r--src/pkg/crypto/cipher/cfb.go72
1 files changed, 0 insertions, 72 deletions
diff --git a/src/pkg/crypto/cipher/cfb.go b/src/pkg/crypto/cipher/cfb.go
deleted file mode 100644
index 9b4eebf5b..000000000
--- a/src/pkg/crypto/cipher/cfb.go
+++ /dev/null
@@ -1,72 +0,0 @@
-// Copyright 2010 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// CFB (Cipher Feedback) Mode.
-
-package cipher
-
-type cfb struct {
- b Block
- next []byte
- out []byte
- outUsed int
-
- decrypt bool
-}
-
-func (x *cfb) XORKeyStream(dst, src []byte) {
- for len(src) > 0 {
- if x.outUsed == len(x.out) {
- x.b.Encrypt(x.out, x.next)
- x.outUsed = 0
- }
-
- if x.decrypt {
- // We can precompute a larger segment of the
- // keystream on decryption. This will allow
- // larger batches for xor, and we should be
- // able to match CTR/OFB performance.
- copy(x.next[x.outUsed:], src)
- }
- n := xorBytes(dst, src, x.out[x.outUsed:])
- if !x.decrypt {
- copy(x.next[x.outUsed:], dst)
- }
- dst = dst[n:]
- src = src[n:]
- x.outUsed += n
- }
-}
-
-// NewCFBEncrypter returns a Stream which encrypts with cipher feedback mode,
-// using the given Block. The iv must be the same length as the Block's block
-// size.
-func NewCFBEncrypter(block Block, iv []byte) Stream {
- return newCFB(block, iv, false)
-}
-
-// NewCFBDecrypter returns a Stream which decrypts with cipher feedback mode,
-// using the given Block. The iv must be the same length as the Block's block
-// size.
-func NewCFBDecrypter(block Block, iv []byte) Stream {
- return newCFB(block, iv, true)
-}
-
-func newCFB(block Block, iv []byte, decrypt bool) Stream {
- blockSize := block.BlockSize()
- if len(iv) != blockSize {
- // stack trace will indicate whether it was de or encryption
- panic("cipher.newCFB: IV length must equal block size")
- }
- x := &cfb{
- b: block,
- out: make([]byte, blockSize),
- next: make([]byte, blockSize),
- outUsed: blockSize,
- decrypt: decrypt,
- }
- copy(x.next, iv)
-
- return x
-}