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Diffstat (limited to 'libgo/go/crypto/aes/cipher.go')
-rw-r--r--libgo/go/crypto/aes/cipher.go71
1 files changed, 71 insertions, 0 deletions
diff --git a/libgo/go/crypto/aes/cipher.go b/libgo/go/crypto/aes/cipher.go
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+++ b/libgo/go/crypto/aes/cipher.go
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+// 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
+ }
+}