Imported Upstream version 1.4upstream/1.4

1 files changed, 66 insertions, 0 deletions

diff --git a/src/crypto/aes/cipher.go b/src/crypto/aes/cipher.go
new file mode 100644
index 000000000..2c6bb0a89
--- /dev/null
+++ b/src/crypto/aes/cipher.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.
+
+package aes
+
+import (
+	"crypto/cipher"
+	"strconv"
+)
+
+// The AES block size in bytes.
+const BlockSize = 16
+
+// A cipher is an instance of AES encryption using a particular key.
+type aesCipher struct {
+	enc []uint32
+	dec []uint32
+}
+
+type KeySizeError int
+
+func (k KeySizeError) Error() string {
+	return "crypto/aes: invalid key size " + strconv.Itoa(int(k))
+}
+
+// NewCipher creates and returns a new cipher.Block.
+// 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.Block, error) {
+	k := len(key)
+	switch k {
+	default:
+		return nil, KeySizeError(k)
+	case 16, 24, 32:
+		break
+	}
+
+	n := k + 28
+	c := &aesCipher{make([]uint32, n), make([]uint32, n)}
+	expandKey(key, c.enc, c.dec)
+	return c, nil
+}
+
+func (c *aesCipher) BlockSize() int { return BlockSize }
+
+func (c *aesCipher) Encrypt(dst, src []byte) {
+	if len(src) < BlockSize {
+		panic("crypto/aes: input not full block")
+	}
+	if len(dst) < BlockSize {
+		panic("crypto/aes: output not full block")
+	}
+	encryptBlock(c.enc, dst, src)
+}
+
+func (c *aesCipher) Decrypt(dst, src []byte) {
+	if len(src) < BlockSize {
+		panic("crypto/aes: input not full block")
+	}
+	if len(dst) < BlockSize {
+		panic("crypto/aes: output not full block")
+	}
+	decryptBlock(c.dec, dst, src)
+}