summaryrefslogtreecommitdiff
path: root/libgo/go/crypto/cipher/cipher.go
diff options
context:
space:
mode:
authorupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
committerupstream source tree <ports@midipix.org>2015-03-15 20:14:05 -0400
commit554fd8c5195424bdbcabf5de30fdc183aba391bd (patch)
tree976dc5ab7fddf506dadce60ae936f43f58787092 /libgo/go/crypto/cipher/cipher.go
downloadcbb-gcc-4.6.4-554fd8c5195424bdbcabf5de30fdc183aba391bd.tar.bz2
cbb-gcc-4.6.4-554fd8c5195424bdbcabf5de30fdc183aba391bd.tar.xz
obtained gcc-4.6.4.tar.bz2 from upstream website;upstream
verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository.
Diffstat (limited to 'libgo/go/crypto/cipher/cipher.go')
-rw-r--r--libgo/go/crypto/cipher/cipher.go63
1 files changed, 63 insertions, 0 deletions
diff --git a/libgo/go/crypto/cipher/cipher.go b/libgo/go/crypto/cipher/cipher.go
new file mode 100644
index 000000000..50516b23a
--- /dev/null
+++ b/libgo/go/crypto/cipher/cipher.go
@@ -0,0 +1,63 @@
+// Copyright 2010 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 cipher 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 cipher
+
+// A Block 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 Block interface {
+ // BlockSize returns the cipher's block size.
+ BlockSize() int
+
+ // Encrypt encrypts the first block in src into dst.
+ // Dst and src may point at the same memory.
+ Encrypt(dst, src []byte)
+
+ // Decrypt decrypts the first block in src into dst.
+ // Dst and src may point at the same memory.
+ Decrypt(dst, src []byte)
+}
+
+// A Stream represents a stream cipher.
+type Stream interface {
+ // XORKeyStream XORs each byte in the given slice with a byte from the
+ // cipher's key stream. Dst and src may point to the same memory.
+ XORKeyStream(dst, src []byte)
+}
+
+// A BlockMode represents a block cipher running in a block-based mode (CBC,
+// ECB etc).
+type BlockMode interface {
+ // BlockSize returns the mode's block size.
+ BlockSize() int
+
+ // CryptBlocks encrypts or decrypts a number of blocks. The length of
+ // src must be a multiple of the block size. Dst and src may point to
+ // the same memory.
+ CryptBlocks(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 dup(p []byte) []byte {
+ q := make([]byte, len(p))
+ copy(q, p)
+ return q
+}