crypto/...: more fixes for bug 2841

1) Remove the Reset() member in crypto/aes and crypto/des (and
   document the change).
2) Turn several empty error structures into vars. Any remaining error
   structures are either non-empty, or will probably become so in the
   future.
3) Implement SetWriteDeadline for TLS sockets. At the moment, the TLS
   status cannot be reused after a Write error, which is probably fine
   for most uses.
4) Make crypto/aes and crypto/des return a cipher.Block.

R=rsc, r
CC=golang-dev
http://codereview.appspot.com/5625045

1 files changed, 4 insertions, 3 deletions

diff --git a/src/pkg/crypto/cipher/ctr_aes_test.go b/src/pkg/crypto/cipher/ctr_aes_test.go
index 8dca9968c..d019ae0d0 100644
--- a/src/pkg/crypto/cipher/ctr_aes_test.go
+++ b/src/pkg/crypto/cipher/ctr_aes_test.go
@@ -8,11 +8,12 @@
 // Special Publication 800-38A, ``Recommendation for Block Cipher
 // Modes of Operation,'' 2001 Edition, pp. 55-58.
 
-package cipher
+package cipher_test
 
 import (
 	"bytes"
 	"crypto/aes"
+	"crypto/cipher"
 	"testing"
 )
 
@@ -76,7 +77,7 @@ func TestCTR_AES(t *testing.T) {
 
 		for j := 0; j <= 5; j += 5 {
 			in := tt.in[0 : len(tt.in)-j]
-			ctr := NewCTR(c, tt.iv)
+			ctr := cipher.NewCTR(c, tt.iv)
 			encrypted := make([]byte, len(in))
 			ctr.XORKeyStream(encrypted, in)
 			if out := tt.out[0:len(in)]; !bytes.Equal(out, encrypted) {
@@ -86,7 +87,7 @@ func TestCTR_AES(t *testing.T) {
 
 		for j := 0; j <= 7; j += 7 {
 			in := tt.out[0 : len(tt.out)-j]
-			ctr := NewCTR(c, tt.iv)
+			ctr := cipher.NewCTR(c, tt.iv)
 			plain := make([]byte, len(in))
 			ctr.XORKeyStream(plain, in)
 			if out := tt.in[0:len(in)]; !bytes.Equal(out, plain) {