From 7249ea4df2b4f12a4e7ed446f270cea87e4ffd34 Mon Sep 17 00:00:00 2001 From: Rob Pike Date: Tue, 9 Jun 2009 09:53:44 -0700 Subject: mv src/lib to src/pkg tests: all.bash passes, gobuild still works, godoc still works. R=rsc OCL=30096 CL=30102 --- src/pkg/crypto/aes/cipher.go | 71 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 src/pkg/crypto/aes/cipher.go (limited to 'src/pkg/crypto/aes/cipher.go') diff --git a/src/pkg/crypto/aes/cipher.go b/src/pkg/crypto/aes/cipher.go new file mode 100644 index 000000000..fd8e43e16 --- /dev/null +++ b/src/pkg/crypto/aes/cipher.go @@ -0,0 +1,71 @@ +// 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. + +package aes + +import ( + "crypto/aes"; + "os"; +) + +// The AES block size in bytes. +const BlockSize = 16; + +// A Cipher is an instance of AES encryption using a particular key. +type Cipher struct { + enc []uint32; + dec []uint32; +} + +// NewCipher creates and returns a new Cipher. +// The key argument should be the AES key, +// either 16, 24, or 32 bytes to select +// AES-128, AES-192, or AES-256. +func NewCipher(key []byte) (*Cipher, os.Error) { + switch len(key) { + default: + return nil, os.ErrorString("crypto/aes: invalid key size"); + case 16, 24, 32: + break; + } + + n := len(key) + 28; + c := &Cipher{make([]uint32, n), make([]uint32, n)}; + expandKey(key, c.enc, c.dec); + return c, nil; +} + +// BlockSize returns the AES block size, 16 bytes. +// It is necessary to satisfy the Key interface in the +// package "crypto/modes". +func (c *Cipher) BlockSize() int { + return BlockSize; +} + +// Encrypt encrypts the 16-byte buffer src using the key k +// 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 AESCBC (see modes.go). +func (c *Cipher) Encrypt(src, dst []byte) { + encryptBlock(c.enc, src, dst); +} + +// Decrypt decrypts the 16-byte buffer src using the key k +// and stores the result in dst. +func (c *Cipher) Decrypt(src, dst []byte) { + decryptBlock(c.dec, src, dst); +} + +// 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.enc); i++ { + c.enc[i] = 0; + } + for i := 0; i < len(c.dec); i++ { + c.dec[i] = 0; + } +} + -- cgit v1.2.3