gcc/libgo/go/crypto/aes/cipher.go
Ian Lance Taylor 7a9389330e Add Go frontend, libgo library, and Go testsuite.
gcc/:
	* gcc.c (default_compilers): Add entry for ".go".
	* common.opt: Add -static-libgo as a driver option.
	* doc/install.texi (Configuration): Mention libgo as an option for
	--enable-shared.  Mention go as an option for --enable-languages.
	* doc/invoke.texi (Overall Options): Mention .go as a file name
	suffix.  Mention go as a -x option.
	* doc/frontends.texi (G++ and GCC): Mention Go as a supported
	language.
	* doc/sourcebuild.texi (Top Level): Mention libgo.
	* doc/standards.texi (Standards): Add section on Go language.
	Move references for other languages into their own section.
	* doc/contrib.texi (Contributors): Mention that I contributed the
	Go frontend.
gcc/testsuite/:
	* lib/go.exp: New file.
	* lib/go-dg.exp: New file.
	* lib/go-torture.exp: New file.
	* lib/target-supports.exp (check_compile): Match // Go.

From-SVN: r167407
2010-12-03 04:34:57 +00:00

72 lines
1.8 KiB
Go

// 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 (
"os"
"strconv"
)
// 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
}
type KeySizeError int
func (k KeySizeError) String() string {
return "crypto/aes: invalid key size " + strconv.Itoa(int(k))
}
// 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) {
k := len(key)
switch k {
default:
return nil, KeySizeError(k)
case 16, 24, 32:
break
}
n := k + 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 Cipher interface in the
// package "crypto/block".
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 CBC (see crypto/block/cbc.go).
func (c *Cipher) Encrypt(dst, src []byte) { encryptBlock(c.enc, dst, src) }
// Decrypt decrypts the 16-byte buffer src using the key k
// and stores the result in dst.
func (c *Cipher) Decrypt(dst, src []byte) { decryptBlock(c.dec, 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.enc); i++ {
c.enc[i] = 0
}
for i := 0; i < len(c.dec); i++ {
c.dec[i] = 0
}
}