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| author | Ian Lance Taylor <iant@google.com> | 2011-01-21 18:19:03 +0000 |
|---|---|---|
| committer | Ian Lance Taylor <ian@gcc.gnu.org> | 2011-01-21 18:19:03 +0000 |
| commit | ff5f50c52c421d75940ef9392211e3ab24d71332 (patch) | |
| tree | 27d8768fb1d25696d3c40b42535eb5e073c278da /libgo/go/crypto/cipher/cfb.go | |
| parent | d6ed1c8903e728f4233122554bab5910853338bd (diff) | |
| download | gcc-ff5f50c52c421d75940ef9392211e3ab24d71332.zip gcc-ff5f50c52c421d75940ef9392211e3ab24d71332.tar.gz gcc-ff5f50c52c421d75940ef9392211e3ab24d71332.tar.bz2 | |
Remove the types float and complex.
Update to current version of Go library.
Update testsuite for removed types.
* go-lang.c (go_langhook_init): Omit float_type_size when calling
go_create_gogo.
* go-c.h: Update declaration of go_create_gogo.
From-SVN: r169098
Diffstat (limited to 'libgo/go/crypto/cipher/cfb.go')
| -rw-r--r-- | libgo/go/crypto/cipher/cfb.go | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/libgo/go/crypto/cipher/cfb.go b/libgo/go/crypto/cipher/cfb.go new file mode 100644 index 0000000..d14165a --- /dev/null +++ b/libgo/go/crypto/cipher/cfb.go @@ -0,0 +1,64 @@ +// 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 + out []byte + outUsed int + decrypt bool +} + +// 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 { + return nil + } + + x := &cfb{ + b: block, + out: make([]byte, blockSize), + outUsed: 0, + decrypt: decrypt, + } + block.Encrypt(x.out, iv) + + return x +} + +func (x *cfb) XORKeyStream(dst, src []byte) { + for i := 0; i < len(src); i++ { + if x.outUsed == len(x.out) { + x.b.Encrypt(x.out, x.out) + x.outUsed = 0 + } + + if x.decrypt { + t := src[i] + dst[i] = src[i] ^ x.out[x.outUsed] + x.out[x.outUsed] = t + } else { + x.out[x.outUsed] ^= src[i] + dst[i] = x.out[x.outUsed] + } + x.outUsed++ + } +} |