From b7ef541f354a4d664391d2b38b27bda01860f72d Mon Sep 17 00:00:00 2001
From: Russ Cox <rsc@golang.org>
Date: Wed, 14 Oct 2009 09:33:15 -0700
Subject: [PATCH] toss crypto/block Digest in favor of hash.Hash

R=r
DELTA=30  (8 added, 15 deleted, 7 changed)
OCL=35677
CL=35713
---
 src/pkg/Make.deps              |  2 +-
 src/pkg/crypto/block/cipher.go | 15 ---------------
 src/pkg/crypto/block/cmac.go   | 11 +++++++++--
 src/pkg/crypto/block/eax.go    |  9 +++++----
 4 files changed, 15 insertions(+), 22 deletions(-)

diff --git a/src/pkg/Make.deps b/src/pkg/Make.deps
index 99c9755232..19942a9d99 100644
--- a/src/pkg/Make.deps
+++ b/src/pkg/Make.deps
@@ -13,7 +13,7 @@ container/list.install:
 container/ring.install:
 container/vector.install:
 crypto/aes.install: os.install strconv.install
-crypto/block.install: fmt.install io.install os.install strconv.install
+crypto/block.install: fmt.install hash.install io.install os.install strconv.install
 crypto/hmac.install: crypto/md5.install crypto/sha1.install hash.install os.install
 crypto/md5.install: hash.install os.install
 crypto/rc4.install: os.install strconv.install
diff --git a/src/pkg/crypto/block/cipher.go b/src/pkg/crypto/block/cipher.go
index ed6db02f7b..8bff1b8782 100644
--- a/src/pkg/crypto/block/cipher.go
+++ b/src/pkg/crypto/block/cipher.go
@@ -8,8 +8,6 @@
 // and NIST Special Publication 800-38A.
 package block
 
-import "io"
-
 // 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
@@ -27,19 +25,6 @@ type Cipher interface {
 	Decrypt(src, dst []byte);
 }
 
-// TODO(rsc): Digest belongs elsewhere.
-
-// A Digest is an implementation of a message digest algorithm.
-// Write data to it and then call Sum to retreive the digest.
-// Calling Reset resets the internal state, as though no data has
-// been written.
-type Digest interface {
-	io.Writer;
-	Sum() []byte;
-	Reset();
-}
-
-
 // Utility routines
 
 func shift1(src, dst []byte) byte {
diff --git a/src/pkg/crypto/block/cmac.go b/src/pkg/crypto/block/cmac.go
index ff8d0b0fbe..667dc7b3e5 100644
--- a/src/pkg/crypto/block/cmac.go
+++ b/src/pkg/crypto/block/cmac.go
@@ -7,7 +7,10 @@
 
 package block
 
-import "os"
+import (
+	"hash";
+	"os";
+)
 
 const (
 	// minimal irreducible polynomial of degree b
@@ -25,7 +28,7 @@ type cmac struct {
 
 // NewCMAC returns a new instance of a CMAC message authentication code
 // digest using the given Cipher.
-func NewCMAC(c Cipher) Digest {
+func NewCMAC(c Cipher) hash.Hash {
 	var r byte;
 	n := c.BlockSize();
 	switch n {
@@ -98,3 +101,7 @@ func (d *cmac) Sum() []byte {
 	d.c.Encrypt(d.digest, d.digest);
 	return d.digest;
 }
+
+func (d *cmac) Size() int {
+	return len(d.digest);
+}
diff --git a/src/pkg/crypto/block/eax.go b/src/pkg/crypto/block/eax.go
index e6dc39195c..3992ea8f7a 100644
--- a/src/pkg/crypto/block/eax.go
+++ b/src/pkg/crypto/block/eax.go
@@ -16,6 +16,7 @@ package block
 
 import (
 	"fmt";
+	"hash";
 	"io";
 	"os";
 )
@@ -32,7 +33,7 @@ func (e *EAXTagError) String() string {
 	return fmt.Sprintf("crypto/block: EAX tag mismatch: read %x but computed %x", e.Read, e.Computed);
 }
 
-func setupEAX(c Cipher, iv, hdr []byte, tagBytes int) (ctrIV, tag []byte, cmac Digest) {
+func setupEAX(c Cipher, iv, hdr []byte, tagBytes int) (ctrIV, tag []byte, cmac hash.Hash) {
 	n := len(iv);
 	if n != c.BlockSize() {
 		panicln("crypto/block: EAX: iv length", n, "!=", c.BlockSize());
@@ -63,7 +64,7 @@ func setupEAX(c Cipher, iv, hdr []byte, tagBytes int) (ctrIV, tag []byte, cmac D
 	return;
 }
 
-func finishEAX(tag []byte, cmac Digest) {
+func finishEAX(tag []byte, cmac hash.Hash) {
 	// Finish CMAC #2 and xor into tag.
 	sum := cmac.Sum();
 	for i := range tag {
@@ -75,7 +76,7 @@ func finishEAX(tag []byte, cmac Digest) {
 // Knows that cmac never returns write errors.
 type cmacWriter struct {
 	w	io.Writer;
-	cmac	Digest;
+	cmac	hash.Hash;
 }
 
 func (cw *cmacWriter) Write(p []byte) (n int, err os.Error) {
@@ -133,7 +134,7 @@ func (x *eaxEncrypter) Close() os.Error {
 // but the latter half is trivial.
 type cmacReader struct {
 	r	io.Reader;
-	cmac	Digest;
+	cmac	hash.Hash;
 	tag	[]byte;
 	tmp	[]byte;
 }
-- 
2.48.1