From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- libgo/go/crypto/rc4/rc4.go | 66 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 libgo/go/crypto/rc4/rc4.go (limited to 'libgo/go/crypto/rc4/rc4.go') diff --git a/libgo/go/crypto/rc4/rc4.go b/libgo/go/crypto/rc4/rc4.go new file mode 100644 index 000000000..65fd195f3 --- /dev/null +++ b/libgo/go/crypto/rc4/rc4.go @@ -0,0 +1,66 @@ +// Copyright 2009 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. + +// This package implements RC4 encryption, as defined in Bruce Schneier's +// Applied Cryptography. +package rc4 + +// BUG(agl): RC4 is in common use but has design weaknesses that make +// it a poor choice for new protocols. + +import ( + "os" + "strconv" +) + +// A Cipher is an instance of RC4 using a particular key. +type Cipher struct { + s [256]byte + i, j uint8 +} + +type KeySizeError int + +func (k KeySizeError) String() string { + return "crypto/rc4: invalid key size " + strconv.Itoa(int(k)) +} + +// NewCipher creates and returns a new Cipher. The key argument should be the +// RC4 key, at least 1 byte and at most 256 bytes. +func NewCipher(key []byte) (*Cipher, os.Error) { + k := len(key) + if k < 1 || k > 256 { + return nil, KeySizeError(k) + } + var c Cipher + for i := 0; i < 256; i++ { + c.s[i] = uint8(i) + } + var j uint8 = 0 + for i := 0; i < 256; i++ { + j += c.s[i] + key[i%k] + c.s[i], c.s[j] = c.s[j], c.s[i] + } + return &c, nil +} + +// XORKeyStream sets dst to the result of XORing src with the key stream. +// Dst and src may be the same slice but otherwise should not overlap. +func (c *Cipher) XORKeyStream(dst, src []byte) { + for i := range src { + c.i += 1 + c.j += c.s[c.i] + c.s[c.i], c.s[c.j] = c.s[c.j], c.s[c.i] + dst[i] = src[i] ^ c.s[c.s[c.i]+c.s[c.j]] + } +} + +// Reset zeros the key data so that it will no longer appear in the +// process's memory. +func (c *Cipher) Reset() { + for i := range c.s { + c.s[i] = 0 + } + c.i, c.j = 0, 0 +} -- cgit v1.2.3