1 files changed, 71 insertions, 0 deletions
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;
+	}
+}
+