x/crypto: Add pkcs12 package for reading pkcs12 data

Package pkcs12 provides some Go implementations of PKCS#12.
This implementation is distilled from https://tools.ietf.org/html/rfc7292 and
referenced documents. It is intented for decoding P12/PFX-stored certificate+key
for use with the crypto/tls package.

Package includes @dgryski's RC2 implementation as a sub package as requested in
https://github.com/golang/go/issues/10621.

Change-Id: I78401241e39cd0099e9082a3a227cf0a3a36e6d1
Reviewed-on: https://go-review.googlesource.com/11986
Reviewed-by: Adam Langley <agl@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>

pkcs12/mac_test.go

@@ -0,0 +1,42 @@
+// Copyright 2015 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 pkcs12
+
+import (
+	"encoding/asn1"
+	"testing"
+)
+
+func TestVerifyMac(t *testing.T) {
+	td := macData{
+		Mac: digestInfo{
+			Digest: []byte{0x18, 0x20, 0x3d, 0xff, 0x1e, 0x16, 0xf4, 0x92, 0xf2, 0xaf, 0xc8, 0x91, 0xa9, 0xba, 0xd6, 0xca, 0x9d, 0xee, 0x51, 0x93},
+		},
+		MacSalt:    []byte{1, 2, 3, 4, 5, 6, 7, 8},
+		Iterations: 2048,
+	}
+
+	message := []byte{11, 12, 13, 14, 15}
+	password, _ := bmpString("")
+
+	td.Mac.Algorithm.Algorithm = asn1.ObjectIdentifier([]int{1, 2, 3})
+	err := verifyMac(&td, message, password)
+	if _, ok := err.(NotImplementedError); !ok {
+		t.Errorf("err: %v", err)
+	}
+
+	td.Mac.Algorithm.Algorithm = asn1.ObjectIdentifier([]int{1, 3, 14, 3, 2, 26})
+	err = verifyMac(&td, message, password)
+	if err != ErrIncorrectPassword {
+		t.Errorf("Expected incorrect password, got err: %v", err)
+	}
+
+	password, _ = bmpString("Sesame open")
+	err = verifyMac(&td, message, password)
+	if err != nil {
+		t.Errorf("err: %v", err)
+	}
+
+}