Finish porting to ONF infrastructure
- change of imports
- Adding vendor folder
- licensing
Change-Id: If2e7ed27d603668b848ae58c135e94a8db13a9e2
diff --git a/vendor/github.com/aead/cmac/cmac.go b/vendor/github.com/aead/cmac/cmac.go
new file mode 100644
index 0000000..1e90314
--- /dev/null
+++ b/vendor/github.com/aead/cmac/cmac.go
@@ -0,0 +1,201 @@
+// Copyright (c) 2016 Andreas Auernhammer. All rights reserved.
+// Use of this source code is governed by a license that can be
+// found in the LICENSE file.
+
+// Package cmac implements the fast CMAC MAC based on
+// a block cipher. This mode of operation fixes security
+// deficiencies of CBC-MAC (CBC-MAC is secure only for
+// fixed-length messages). CMAC is equal to OMAC1.
+// This implementations supports block ciphers with a
+// block size of:
+// - 64 bit
+// - 128 bit
+// - 256 bit
+// - 512 bit
+// - 1024 bit
+// Common ciphers like AES, Serpent etc. operate on 128 bit
+// blocks. 256, 512 and 1024 are supported for the Threefish
+// tweakable block cipher. Ciphers with 64 bit blocks are
+// supported, but not recommened.
+// CMAC (with AES) is specified in RFC 4493 and RFC 4494.
+package cmac // import "github.com/aead/cmac"
+
+import (
+ "crypto/cipher"
+ "crypto/subtle"
+ "errors"
+ "hash"
+)
+
+const (
+ // minimal irreducible polynomial for blocksize
+ p64 = 0x1b // for 64 bit block ciphers
+ p128 = 0x87 // for 128 bit block ciphers (like AES)
+ p256 = 0x425 // special for large block ciphers (Threefish)
+ p512 = 0x125 // special for large block ciphers (Threefish)
+ p1024 = 0x80043 // special for large block ciphers (Threefish)
+)
+
+var (
+ errUnsupportedCipher = errors.New("cipher block size not supported")
+ errInvalidTagSize = errors.New("tags size must between 1 and the cipher's block size")
+)
+
+// Sum computes the CMAC checksum with the given tagsize of msg using the cipher.Block.
+func Sum(msg []byte, c cipher.Block, tagsize int) ([]byte, error) {
+ h, err := NewWithTagSize(c, tagsize)
+ if err != nil {
+ return nil, err
+ }
+ h.Write(msg)
+ return h.Sum(nil), nil
+}
+
+// Verify computes the CMAC checksum with the given tagsize of msg and compares
+// it with the given mac. This functions returns true if and only if the given mac
+// is equal to the computed one.
+func Verify(mac, msg []byte, c cipher.Block, tagsize int) bool {
+ sum, err := Sum(msg, c, tagsize)
+ if err != nil {
+ return false
+ }
+ return subtle.ConstantTimeCompare(mac, sum) == 1
+}
+
+// New returns a hash.Hash computing the CMAC checksum.
+func New(c cipher.Block) (hash.Hash, error) {
+ return NewWithTagSize(c, c.BlockSize())
+}
+
+// NewWithTagSize returns a hash.Hash computing the CMAC checksum with the
+// given tag size. The tag size must between the 1 and the cipher's block size.
+func NewWithTagSize(c cipher.Block, tagsize int) (hash.Hash, error) {
+ blocksize := c.BlockSize()
+
+ if tagsize <= 0 || tagsize > blocksize {
+ return nil, errInvalidTagSize
+ }
+
+ var p int
+ switch blocksize {
+ default:
+ return nil, errUnsupportedCipher
+ case 8:
+ p = p64
+ case 16:
+ p = p128
+ case 32:
+ p = p256
+ case 64:
+ p = p512
+ case 128:
+ p = p1024
+ }
+
+ m := &macFunc{
+ cipher: c,
+ k0: make([]byte, blocksize),
+ k1: make([]byte, blocksize),
+ buf: make([]byte, blocksize),
+ }
+ m.tagsize = tagsize
+ c.Encrypt(m.k0, m.k0)
+
+ v := shift(m.k0, m.k0)
+ m.k0[blocksize-1] ^= byte(subtle.ConstantTimeSelect(v, p, 0))
+
+ v = shift(m.k1, m.k0)
+ m.k1[blocksize-1] ^= byte(subtle.ConstantTimeSelect(v, p, 0))
+
+ return m, nil
+}
+
+// The CMAC message auth. function
+type macFunc struct {
+ cipher cipher.Block
+ k0, k1 []byte
+ buf []byte
+ off int
+ tagsize int
+}
+
+func (h *macFunc) Size() int { return h.cipher.BlockSize() }
+
+func (h *macFunc) BlockSize() int { return h.cipher.BlockSize() }
+
+func (h *macFunc) Reset() {
+ for i := range h.buf {
+ h.buf[i] = 0
+ }
+ h.off = 0
+}
+
+func (h *macFunc) Write(msg []byte) (int, error) {
+ bs := h.BlockSize()
+ n := len(msg)
+
+ if h.off > 0 {
+ dif := bs - h.off
+ if n > dif {
+ xor(h.buf[h.off:], msg[:dif])
+ msg = msg[dif:]
+ h.cipher.Encrypt(h.buf, h.buf)
+ h.off = 0
+ } else {
+ xor(h.buf[h.off:], msg)
+ h.off += n
+ return n, nil
+ }
+ }
+
+ if length := len(msg); length > bs {
+ nn := length & (^(bs - 1))
+ if length == nn {
+ nn -= bs
+ }
+ for i := 0; i < nn; i += bs {
+ xor(h.buf, msg[i:i+bs])
+ h.cipher.Encrypt(h.buf, h.buf)
+ }
+ msg = msg[nn:]
+ }
+
+ if length := len(msg); length > 0 {
+ xor(h.buf[h.off:], msg)
+ h.off += length
+ }
+
+ return n, nil
+}
+
+func (h *macFunc) Sum(b []byte) []byte {
+ blocksize := h.cipher.BlockSize()
+
+ // Don't change the buffer so the
+ // caller can keep writing and suming.
+ hash := make([]byte, blocksize)
+
+ if h.off < blocksize {
+ copy(hash, h.k1)
+ } else {
+ copy(hash, h.k0)
+ }
+
+ xor(hash, h.buf)
+ if h.off < blocksize {
+ hash[h.off] ^= 0x80
+ }
+
+ h.cipher.Encrypt(hash, hash)
+ return append(b, hash[:h.tagsize]...)
+}
+
+func shift(dst, src []byte) int {
+ var b, bit byte
+ for i := len(src) - 1; i >= 0; i-- { // a range would be nice
+ bit = src[i] >> 7
+ dst[i] = src[i]<<1 | b
+ b = bit
+ }
+ return int(b)
+}