1 files changed, 57 insertions, 0 deletions
diff --git a/libgo/go/crypto/block/cipher.go b/libgo/go/crypto/block/cipher.go
new file mode 100644
index 0000000000..e1099e9a10
--- /dev/null
+++ b/libgo/go/crypto/block/cipher.go
@@ -0,0 +1,57 @@
+// 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.
+
+// The block package is deprecated, use cipher instead.
+// The block package implements standard block cipher modes
+// that can be wrapped around low-level block cipher implementations.
+// See http://csrc.nist.gov/groups/ST/toolkit/BCM/current_modes.html
+// and NIST Special Publication 800-38A.
+package block
+
+// A Cipher represents an implementation of block cipher
+// using a given key.  It provides the capability to encrypt
+// or decrypt individual blocks.  The mode implementations
+// extend that capability to streams of blocks.
+type Cipher interface {
+	// BlockSize returns the cipher's block size.
+	BlockSize() int
+
+	// Encrypt encrypts the first block in src into dst.
+	// Src and dst may point at the same memory.
+	Encrypt(dst, src []byte)
+
+	// Decrypt decrypts the first block in src into dst.
+	// Src and dst may point at the same memory.
+	Decrypt(dst, src []byte)
+}
+
+// Utility routines
+
+func shift1(dst, src []byte) byte {
+	var b byte
+	for i := len(src) - 1; i >= 0; i-- {
+		bb := src[i] >> 7
+		dst[i] = src[i]<<1 | b
+		b = bb
+	}
+	return b
+}
+
+func same(p, q []byte) bool {
+	if len(p) != len(q) {
+		return false
+	}
+	for i := 0; i < len(p); i++ {
+		if p[i] != q[i] {
+			return false
+		}
+	}
+	return true
+}
+
+func dup(p []byte) []byte {
+	q := make([]byte, len(p))
+	copy(q, p)
+	return q
+}