crypto: update incorrect references to Cipher interface; should be Block.

R=gri, rsc, r
CC=golang-dev
https://golang.org/cl/5372050

doc/go_spec.html

 <!-- title The Go Programming Language Specification -->
-<!-- subtitle Version of November 1, 2011 -->
+<!-- subtitle Version of November 9, 2011 -->
 
 <!--
 TODO
@@ -1688,7 +1688,7 @@ type TreeNode struct {
 	value *Comparable
 }
 
-type Cipher interface {
+type Block interface {
 	BlockSize() int
 	Encrypt(src, dst []byte)
 	Decrypt(src, dst []byte)
@@ -1720,8 +1720,8 @@ type PrintableMutex struct {
 	Mutex
 }
 
-// MyCipher is an interface type that has the same method set as Cipher.
-type MyCipher Cipher
+// MyBlock is an interface type that has the same method set as Block.
+type MyBlock Block
 </pre>
 
 <p>

src/pkg/crypto/aes/cipher.go

@@ -41,7 +41,7 @@ func NewCipher(key []byte) (*Cipher, error) {
 }
 
 // BlockSize returns the AES block size, 16 bytes.
-// It is necessary to satisfy the Cipher interface in the
+// It is necessary to satisfy the Block interface in the
 // package "crypto/cipher".
 func (c *Cipher) BlockSize() int { return BlockSize }
 

src/pkg/crypto/blowfish/cipher.go

@@ -54,7 +54,7 @@ func NewSaltedCipher(key, salt []byte) (*Cipher, error) {
 }
 
 // BlockSize returns the Blowfish block size, 8 bytes.
-// It is necessary to satisfy the Cipher interface in the
+// It is necessary to satisfy the Block interface in the
 // package "crypto/cipher".
 func (c *Cipher) BlockSize() int { return BlockSize }
 

src/pkg/crypto/xtea/cipher.go

@@ -44,7 +44,7 @@ func NewCipher(key []byte) (*Cipher, error) {
 }
 
 // BlockSize returns the XTEA block size, 8 bytes.
-// It is necessary to satisfy the Cipher interface in the
+// It is necessary to satisfy the Block interface in the
 // package "crypto/cipher".
 func (c *Cipher) BlockSize() int { return BlockSize }