go.crypto: initial code

Manual edits to README.
Moved from main Go repository, deleted Makefiles, ran gofix -r go1rename.

Tested with: go test code.google.com/p/go.crypto/...

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5564059

ssh/cipher_test.go

@@ -0,0 +1,62 @@
+// Copyright 2011 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.
+
+package ssh
+
+import (
+	"bytes"
+	"testing"
+)
+
+// TestCipherReversal tests that each cipher factory produces ciphers that can
+// encrypt and decrypt some data successfully.
+func TestCipherReversal(t *testing.T) {
+	testData := []byte("abcdefghijklmnopqrstuvwxyz012345")
+	testKey := []byte("AbCdEfGhIjKlMnOpQrStUvWxYz012345")
+	testIv := []byte("sdflkjhsadflkjhasdflkjhsadfklhsa")
+
+	cryptBuffer := make([]byte, 32)
+
+	for name, cipherMode := range cipherModes {
+		encrypter, err := cipherMode.createCipher(testKey, testIv)
+		if err != nil {
+			t.Errorf("failed to create encrypter for %q: %s", name, err)
+			continue
+		}
+		decrypter, err := cipherMode.createCipher(testKey, testIv)
+		if err != nil {
+			t.Errorf("failed to create decrypter for %q: %s", name, err)
+			continue
+		}
+
+		copy(cryptBuffer, testData)
+
+		encrypter.XORKeyStream(cryptBuffer, cryptBuffer)
+		if name == "none" {
+			if !bytes.Equal(cryptBuffer, testData) {
+				t.Errorf("encryption made change with 'none' cipher")
+				continue
+			}
+		} else {
+			if bytes.Equal(cryptBuffer, testData) {
+				t.Errorf("encryption made no change with %q", name)
+				continue
+			}
+		}
+
+		decrypter.XORKeyStream(cryptBuffer, cryptBuffer)
+		if !bytes.Equal(cryptBuffer, testData) {
+			t.Errorf("decrypted bytes not equal to input with %q", name)
+			continue
+		}
+	}
+}
+
+func TestDefaultCiphersExist(t *testing.T) {
+	for _, cipherAlgo := range DefaultCipherOrder {
+		if _, ok := cipherModes[cipherAlgo]; !ok {
+			t.Errorf("default cipher %q is unknown", cipherAlgo)
+		}
+	}
+}