Support webauthn (#17957)

Migrate from U2F to Webauthn

Co-authored-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

12 files changed, 2455 insertions, 0 deletions

diff --git a/vendor/golang.org/x/crypto/cryptobyte/asn1.go b/vendor/golang.org/x/crypto/cryptobyte/asn1.go
new file mode 100644
index 0000000000..83c776de08
--- /dev/null
+++ b/vendor/golang.org/x/crypto/cryptobyte/asn1.go
@@ -0,0 +1,804 @@
+// Copyright 2017 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 cryptobyte
+
+import (
+	encoding_asn1 "encoding/asn1"
+	"fmt"
+	"math/big"
+	"reflect"
+	"time"
+
+	"golang.org/x/crypto/cryptobyte/asn1"
+)
+
+// This file contains ASN.1-related methods for String and Builder.
+
+// Builder
+
+// AddASN1Int64 appends a DER-encoded ASN.1 INTEGER.
+func (b *Builder) AddASN1Int64(v int64) {
+	b.addASN1Signed(asn1.INTEGER, v)
+}
+
+// AddASN1Int64WithTag appends a DER-encoded ASN.1 INTEGER with the
+// given tag.
+func (b *Builder) AddASN1Int64WithTag(v int64, tag asn1.Tag) {
+	b.addASN1Signed(tag, v)
+}
+
+// AddASN1Enum appends a DER-encoded ASN.1 ENUMERATION.
+func (b *Builder) AddASN1Enum(v int64) {
+	b.addASN1Signed(asn1.ENUM, v)
+}
+
+func (b *Builder) addASN1Signed(tag asn1.Tag, v int64) {
+	b.AddASN1(tag, func(c *Builder) {
+		length := 1
+		for i := v; i >= 0x80 || i < -0x80; i >>= 8 {
+			length++
+		}
+
+		for ; length > 0; length-- {
+			i := v >> uint((length-1)*8) & 0xff
+			c.AddUint8(uint8(i))
+		}
+	})
+}
+
+// AddASN1Uint64 appends a DER-encoded ASN.1 INTEGER.
+func (b *Builder) AddASN1Uint64(v uint64) {
+	b.AddASN1(asn1.INTEGER, func(c *Builder) {
+		length := 1
+		for i := v; i >= 0x80; i >>= 8 {
+			length++
+		}
+
+		for ; length > 0; length-- {
+			i := v >> uint((length-1)*8) & 0xff
+			c.AddUint8(uint8(i))
+		}
+	})
+}
+
+// AddASN1BigInt appends a DER-encoded ASN.1 INTEGER.
+func (b *Builder) AddASN1BigInt(n *big.Int) {
+	if b.err != nil {
+		return
+	}
+
+	b.AddASN1(asn1.INTEGER, func(c *Builder) {
+		if n.Sign() < 0 {
+			// A negative number has to be converted to two's-complement form. So we
+			// invert and subtract 1. If the most-significant-bit isn't set then
+			// we'll need to pad the beginning with 0xff in order to keep the number
+			// negative.
+			nMinus1 := new(big.Int).Neg(n)
+			nMinus1.Sub(nMinus1, bigOne)
+			bytes := nMinus1.Bytes()
+			for i := range bytes {
+				bytes[i] ^= 0xff
+			}
+			if len(bytes) == 0 || bytes[0]&0x80 == 0 {
+				c.add(0xff)
+			}
+			c.add(bytes...)
+		} else if n.Sign() == 0 {
+			c.add(0)
+		} else {
+			bytes := n.Bytes()
+			if bytes[0]&0x80 != 0 {
+				c.add(0)
+			}
+			c.add(bytes...)
+		}
+	})
+}
+
+// AddASN1OctetString appends a DER-encoded ASN.1 OCTET STRING.
+func (b *Builder) AddASN1OctetString(bytes []byte) {
+	b.AddASN1(asn1.OCTET_STRING, func(c *Builder) {
+		c.AddBytes(bytes)
+	})
+}
+
+const generalizedTimeFormatStr = "20060102150405Z0700"
+
+// AddASN1GeneralizedTime appends a DER-encoded ASN.1 GENERALIZEDTIME.
+func (b *Builder) AddASN1GeneralizedTime(t time.Time) {
+	if t.Year() < 0 || t.Year() > 9999 {
+		b.err = fmt.Errorf("cryptobyte: cannot represent %v as a GeneralizedTime", t)
+		return
+	}
+	b.AddASN1(asn1.GeneralizedTime, func(c *Builder) {
+		c.AddBytes([]byte(t.Format(generalizedTimeFormatStr)))
+	})
+}
+
+// AddASN1UTCTime appends a DER-encoded ASN.1 UTCTime.
+func (b *Builder) AddASN1UTCTime(t time.Time) {
+	b.AddASN1(asn1.UTCTime, func(c *Builder) {
+		// As utilized by the X.509 profile, UTCTime can only
+		// represent the years 1950 through 2049.
+		if t.Year() < 1950 || t.Year() >= 2050 {
+			b.err = fmt.Errorf("cryptobyte: cannot represent %v as a UTCTime", t)
+			return
+		}
+		c.AddBytes([]byte(t.Format(defaultUTCTimeFormatStr)))
+	})
+}
+
+// AddASN1BitString appends a DER-encoded ASN.1 BIT STRING. This does not
+// support BIT STRINGs that are not a whole number of bytes.
+func (b *Builder) AddASN1BitString(data []byte) {
+	b.AddASN1(asn1.BIT_STRING, func(b *Builder) {
+		b.AddUint8(0)
+		b.AddBytes(data)
+	})
+}
+
+func (b *Builder) addBase128Int(n int64) {
+	var length int
+	if n == 0 {
+		length = 1
+	} else {
+		for i := n; i > 0; i >>= 7 {
+			length++
+		}
+	}
+
+	for i := length - 1; i >= 0; i-- {
+		o := byte(n >> uint(i*7))
+		o &= 0x7f
+		if i != 0 {
+			o |= 0x80
+		}
+
+		b.add(o)
+	}
+}
+
+func isValidOID(oid encoding_asn1.ObjectIdentifier) bool {
+	if len(oid) < 2 {
+		return false
+	}
+
+	if oid[0] > 2 || (oid[0] <= 1 && oid[1] >= 40) {
+		return false
+	}
+
+	for _, v := range oid {
+		if v < 0 {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (b *Builder) AddASN1ObjectIdentifier(oid encoding_asn1.ObjectIdentifier) {
+	b.AddASN1(asn1.OBJECT_IDENTIFIER, func(b *Builder) {
+		if !isValidOID(oid) {
+			b.err = fmt.Errorf("cryptobyte: invalid OID: %v", oid)
+			return
+		}
+
+		b.addBase128Int(int64(oid[0])*40 + int64(oid[1]))
+		for _, v := range oid[2:] {
+			b.addBase128Int(int64(v))
+		}
+	})
+}
+
+func (b *Builder) AddASN1Boolean(v bool) {
+	b.AddASN1(asn1.BOOLEAN, func(b *Builder) {
+		if v {
+			b.AddUint8(0xff)
+		} else {
+			b.AddUint8(0)
+		}
+	})
+}
+
+func (b *Builder) AddASN1NULL() {
+	b.add(uint8(asn1.NULL), 0)
+}
+
+// MarshalASN1 calls encoding_asn1.Marshal on its input and appends the result if
+// successful or records an error if one occurred.
+func (b *Builder) MarshalASN1(v interface{}) {
+	// NOTE(martinkr): This is somewhat of a hack to allow propagation of
+	// encoding_asn1.Marshal errors into Builder.err. N.B. if you call MarshalASN1 with a
+	// value embedded into a struct, its tag information is lost.
+	if b.err != nil {
+		return
+	}
+	bytes, err := encoding_asn1.Marshal(v)
+	if err != nil {
+		b.err = err
+		return
+	}
+	b.AddBytes(bytes)
+}
+
+// AddASN1 appends an ASN.1 object. The object is prefixed with the given tag.
+// Tags greater than 30 are not supported and result in an error (i.e.
+// low-tag-number form only). The child builder passed to the
+// BuilderContinuation can be used to build the content of the ASN.1 object.
+func (b *Builder) AddASN1(tag asn1.Tag, f BuilderContinuation) {
+	if b.err != nil {
+		return
+	}
+	// Identifiers with the low five bits set indicate high-tag-number format
+	// (two or more octets), which we don't support.
+	if tag&0x1f == 0x1f {
+		b.err = fmt.Errorf("cryptobyte: high-tag number identifier octects not supported: 0x%x", tag)
+		return
+	}
+	b.AddUint8(uint8(tag))
+	b.addLengthPrefixed(1, true, f)
+}
+
+// String
+
+// ReadASN1Boolean decodes an ASN.1 BOOLEAN and converts it to a boolean
+// representation into out and advances. It reports whether the read
+// was successful.
+func (s *String) ReadASN1Boolean(out *bool) bool {
+	var bytes String
+	if !s.ReadASN1(&bytes, asn1.BOOLEAN) || len(bytes) != 1 {
+		return false
+	}
+
+	switch bytes[0] {
+	case 0:
+		*out = false
+	case 0xff:
+		*out = true
+	default:
+		return false
+	}
+
+	return true
+}
+
+var bigIntType = reflect.TypeOf((*big.Int)(nil)).Elem()
+
+// ReadASN1Integer decodes an ASN.1 INTEGER into out and advances. If out does
+// not point to an integer or to a big.Int, it panics. It reports whether the
+// read was successful.
+func (s *String) ReadASN1Integer(out interface{}) bool {
+	if reflect.TypeOf(out).Kind() != reflect.Ptr {
+		panic("out is not a pointer")
+	}
+	switch reflect.ValueOf(out).Elem().Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		var i int64
+		if !s.readASN1Int64(&i) || reflect.ValueOf(out).Elem().OverflowInt(i) {
+			return false
+		}
+		reflect.ValueOf(out).Elem().SetInt(i)
+		return true
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+		var u uint64
+		if !s.readASN1Uint64(&u) || reflect.ValueOf(out).Elem().OverflowUint(u) {
+			return false
+		}
+		reflect.ValueOf(out).Elem().SetUint(u)
+		return true
+	case reflect.Struct:
+		if reflect.TypeOf(out).Elem() == bigIntType {
+			return s.readASN1BigInt(out.(*big.Int))
+		}
+	}
+	panic("out does not point to an integer type")
+}
+
+func checkASN1Integer(bytes []byte) bool {
+	if len(bytes) == 0 {
+		// An INTEGER is encoded with at least one octet.
+		return false
+	}
+	if len(bytes) == 1 {
+		return true
+	}
+	if bytes[0] == 0 && bytes[1]&0x80 == 0 || bytes[0] == 0xff && bytes[1]&0x80 == 0x80 {
+		// Value is not minimally encoded.
+		return false
+	}
+	return true
+}
+
+var bigOne = big.NewInt(1)
+
+func (s *String) readASN1BigInt(out *big.Int) bool {
+	var bytes String
+	if !s.ReadASN1(&bytes, asn1.INTEGER) || !checkASN1Integer(bytes) {
+		return false
+	}
+	if bytes[0]&0x80 == 0x80 {
+		// Negative number.
+		neg := make([]byte, len(bytes))
+		for i, b := range bytes {
+			neg[i] = ^b
+		}
+		out.SetBytes(neg)
+		out.Add(out, bigOne)
+		out.Neg(out)
+	} else {
+		out.SetBytes(bytes)
+	}
+	return true
+}
+
+func (s *String) readASN1Int64(out *int64) bool {
+	var bytes String
+	if !s.ReadASN1(&bytes, asn1.INTEGER) || !checkASN1Integer(bytes) || !asn1Signed(out, bytes) {
+		return false
+	}
+	return true
+}
+
+func asn1Signed(out *int64, n []byte) bool {
+	length := len(n)
+	if length > 8 {
+		return false
+	}
+	for i := 0; i < length; i++ {
+		*out <<= 8
+		*out |= int64(n[i])
+	}
+	// Shift up and down in order to sign extend the result.
+	*out <<= 64 - uint8(length)*8
+	*out >>= 64 - uint8(length)*8
+	return true
+}
+
+func (s *String) readASN1Uint64(out *uint64) bool {
+	var bytes String
+	if !s.ReadASN1(&bytes, asn1.INTEGER) || !checkASN1Integer(bytes) || !asn1Unsigned(out, bytes) {
+		return false
+	}
+	return true
+}
+
+func asn1Unsigned(out *uint64, n []byte) bool {
+	length := len(n)
+	if length > 9 || length == 9 && n[0] != 0 {
+		// Too large for uint64.
+		return false
+	}
+	if n[0]&0x80 != 0 {
+		// Negative number.
+		return false
+	}
+	for i := 0; i < length; i++ {
+		*out <<= 8
+		*out |= uint64(n[i])
+	}
+	return true
+}
+
+// ReadASN1Int64WithTag decodes an ASN.1 INTEGER with the given tag into out
+// and advances. It reports whether the read was successful and resulted in a
+// value that can be represented in an int64.
+func (s *String) ReadASN1Int64WithTag(out *int64, tag asn1.Tag) bool {
+	var bytes String
+	return s.ReadASN1(&bytes, tag) && checkASN1Integer(bytes) && asn1Signed(out, bytes)
+}
+
+// ReadASN1Enum decodes an ASN.1 ENUMERATION into out and advances. It reports
+// whether the read was successful.
+func (s *String) ReadASN1Enum(out *int) bool {
+	var bytes String
+	var i int64
+	if !s.ReadASN1(&bytes, asn1.ENUM) || !checkASN1Integer(bytes) || !asn1Signed(&i, bytes) {
+		return false
+	}
+	if int64(int(i)) != i {
+		return false
+	}
+	*out = int(i)
+	return true
+}
+
+func (s *String) readBase128Int(out *int) bool {
+	ret := 0
+	for i := 0; len(*s) > 0; i++ {
+		if i == 4 {
+			return false
+		}
+		ret <<= 7
+		b := s.read(1)[0]
+		ret |= int(b & 0x7f)
+		if b&0x80 == 0 {
+			*out = ret
+			return true
+		}
+	}
+	return false // truncated
+}
+
+// ReadASN1ObjectIdentifier decodes an ASN.1 OBJECT IDENTIFIER into out and
+// advances. It reports whether the read was successful.
+func (s *String) ReadASN1ObjectIdentifier(out *encoding_asn1.ObjectIdentifier) bool {
+	var bytes String
+	if !s.ReadASN1(&bytes, asn1.OBJECT_IDENTIFIER) || len(bytes) == 0 {
+		return false
+	}
+
+	// In the worst case, we get two elements from the first byte (which is
+	// encoded differently) and then every varint is a single byte long.
+	components := make([]int, len(bytes)+1)
+
+	// The first varint is 40*value1 + value2:
+	// According to this packing, value1 can take the values 0, 1 and 2 only.
+	// When value1 = 0 or value1 = 1, then value2 is <= 39. When value1 = 2,
+	// then there are no restrictions on value2.
+	var v int
+	if !bytes.readBase128Int(&v) {
+		return false
+	}
+	if v < 80 {
+		components[0] = v / 40
+		components[1] = v % 40
+	} else {
+		components[0] = 2
+		components[1] = v - 80
+	}
+
+	i := 2
+	for ; len(bytes) > 0; i++ {
+		if !bytes.readBase128Int(&v) {
+			return false
+		}
+		components[i] = v
+	}
+	*out = components[:i]
+	return true
+}
+
+// ReadASN1GeneralizedTime decodes an ASN.1 GENERALIZEDTIME into out and
+// advances. It reports whether the read was successful.
+func (s *String) ReadASN1GeneralizedTime(out *time.Time) bool {
+	var bytes String
+	if !s.ReadASN1(&bytes, asn1.GeneralizedTime) {
+		return false
+	}
+	t := string(bytes)
+	res, err := time.Parse(generalizedTimeFormatStr, t)
+	if err != nil {
+		return false
+	}
+	if serialized := res.Format(generalizedTimeFormatStr); serialized != t {
+		return false
+	}
+	*out = res
+	return true
+}
+
+const defaultUTCTimeFormatStr = "060102150405Z0700"
+
+// ReadASN1UTCTime decodes an ASN.1 UTCTime into out and advances.
+// It reports whether the read was successful.
+func (s *String) ReadASN1UTCTime(out *time.Time) bool {
+	var bytes String
+	if !s.ReadASN1(&bytes, asn1.UTCTime) {
+		return false
+	}
+	t := string(bytes)
+
+	formatStr := defaultUTCTimeFormatStr
+	var err error
+	res, err := time.Parse(formatStr, t)
+	if err != nil {
+		// Fallback to minute precision if we can't parse second
+		// precision. If we are following X.509 or X.690 we shouldn't
+		// support this, but we do.
+		formatStr = "0601021504Z0700"
+		res, err = time.Parse(formatStr, t)
+	}
+	if err != nil {
+		return false
+	}
+
+	if serialized := res.Format(formatStr); serialized != t {
+		return false
+	}
+
+	if res.Year() >= 2050 {
+		// UTCTime interprets the low order digits 50-99 as 1950-99.
+		// This only applies to its use in the X.509 profile.
+		// See https://tools.ietf.org/html/rfc5280#section-4.1.2.5.1
+		res = res.AddDate(-100, 0, 0)
+	}
+	*out = res
+	return true
+}
+
+// ReadASN1BitString decodes an ASN.1 BIT STRING into out and advances.
+// It reports whether the read was successful.
+func (s *String) ReadASN1BitString(out *encoding_asn1.BitString) bool {
+	var bytes String
+	if !s.ReadASN1(&bytes, asn1.BIT_STRING) || len(bytes) == 0 ||
+		len(bytes)*8/8 != len(bytes) {
+		return false
+	}
+
+	paddingBits := uint8(bytes[0])
+	bytes = bytes[1:]
+	if paddingBits > 7 ||
+		len(bytes) == 0 && paddingBits != 0 ||
+		len(bytes) > 0 && bytes[len(bytes)-1]&(1<<paddingBits-1) != 0 {
+		return false
+	}
+
+	out.BitLength = len(bytes)*8 - int(paddingBits)
+	out.Bytes = bytes
+	return true
+}
+
+// ReadASN1BitString decodes an ASN.1 BIT STRING into out and advances. It is
+// an error if the BIT STRING is not a whole number of bytes. It reports
+// whether the read was successful.
+func (s *String) ReadASN1BitStringAsBytes(out *[]byte) bool {
+	var bytes String
+	if !s.ReadASN1(&bytes, asn1.BIT_STRING) || len(bytes) == 0 {
+		return false
+	}
+
+	paddingBits := uint8(bytes[0])
+	if paddingBits != 0 {
+		return false
+	}
+	*out = bytes[1:]
+	return true
+}
+
+// ReadASN1Bytes reads the contents of a DER-encoded ASN.1 element (not including
+// tag and length bytes) into out, and advances. The element must match the
+// given tag. It reports whether the read was successful.
+func (s *String) ReadASN1Bytes(out *[]byte, tag asn1.Tag) bool {
+	return s.ReadASN1((*String)(out), tag)
+}
+
+// ReadASN1 reads the contents of a DER-encoded ASN.1 element (not including
+// tag and length bytes) into out, and advances. The element must match the
+// given tag. It reports whether the read was successful.
+//
+// Tags greater than 30 are not supported (i.e. low-tag-number format only).
+func (s *String) ReadASN1(out *String, tag asn1.Tag) bool {
+	var t asn1.Tag
+	if !s.ReadAnyASN1(out, &t) || t != tag {
+		return false
+	}
+	return true
+}
+
+// ReadASN1Element reads the contents of a DER-encoded ASN.1 element (including
+// tag and length bytes) into out, and advances. The element must match the
+// given tag. It reports whether the read was successful.
+//
+// Tags greater than 30 are not supported (i.e. low-tag-number format only).
+func (s *String) ReadASN1Element(out *String, tag asn1.Tag) bool {
+	var t asn1.Tag
+	if !s.ReadAnyASN1Element(out, &t) || t != tag {
+		return false
+	}
+	return true
+}
+
+// ReadAnyASN1 reads the contents of a DER-encoded ASN.1 element (not including
+// tag and length bytes) into out, sets outTag to its tag, and advances.
+// It reports whether the read was successful.
+//
+// Tags greater than 30 are not supported (i.e. low-tag-number format only).
+func (s *String) ReadAnyASN1(out *String, outTag *asn1.Tag) bool {
+	return s.readASN1(out, outTag, true /* skip header */)
+}
+
+// ReadAnyASN1Element reads the contents of a DER-encoded ASN.1 element
+// (including tag and length bytes) into out, sets outTag to is tag, and
+// advances. It reports whether the read was successful.
+//
+// Tags greater than 30 are not supported (i.e. low-tag-number format only).
+func (s *String) ReadAnyASN1Element(out *String, outTag *asn1.Tag) bool {
+	return s.readASN1(out, outTag, false /* include header */)
+}
+
+// PeekASN1Tag reports whether the next ASN.1 value on the string starts with
+// the given tag.
+func (s String) PeekASN1Tag(tag asn1.Tag) bool {
+	if len(s) == 0 {
+		return false
+	}
+	return asn1.Tag(s[0]) == tag
+}
+
+// SkipASN1 reads and discards an ASN.1 element with the given tag. It
+// reports whether the operation was successful.
+func (s *String) SkipASN1(tag asn1.Tag) bool {
+	var unused String
+	return s.ReadASN1(&unused, tag)
+}
+
+// ReadOptionalASN1 attempts to read the contents of a DER-encoded ASN.1
+// element (not including tag and length bytes) tagged with the given tag into
+// out. It stores whether an element with the tag was found in outPresent,
+// unless outPresent is nil. It reports whether the read was successful.
+func (s *String) ReadOptionalASN1(out *String, outPresent *bool, tag asn1.Tag) bool {
+	present := s.PeekASN1Tag(tag)
+	if outPresent != nil {
+		*outPresent = present
+	}
+	if present && !s.ReadASN1(out, tag) {
+		return false
+	}
+	return true
+}
+
+// SkipOptionalASN1 advances s over an ASN.1 element with the given tag, or
+// else leaves s unchanged. It reports whether the operation was successful.
+func (s *String) SkipOptionalASN1(tag asn1.Tag) bool {
+	if !s.PeekASN1Tag(tag) {
+		return true
+	}
+	var unused String
+	return s.ReadASN1(&unused, tag)
+}
+
+// ReadOptionalASN1Integer attempts to read an optional ASN.1 INTEGER
+// explicitly tagged with tag into out and advances. If no element with a
+// matching tag is present, it writes defaultValue into out instead. If out
+// does not point to an integer or to a big.Int, it panics. It reports
+// whether the read was successful.
+func (s *String) ReadOptionalASN1Integer(out interface{}, tag asn1.Tag, defaultValue interface{}) bool {
+	if reflect.TypeOf(out).Kind() != reflect.Ptr {
+		panic("out is not a pointer")
+	}
+	var present bool
+	var i String
+	if !s.ReadOptionalASN1(&i, &present, tag) {
+		return false
+	}
+	if !present {
+		switch reflect.ValueOf(out).Elem().Kind() {
+		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
+			reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
+			reflect.ValueOf(out).Elem().Set(reflect.ValueOf(defaultValue))
+		case reflect.Struct:
+			if reflect.TypeOf(out).Elem() != bigIntType {
+				panic("invalid integer type")
+			}
+			if reflect.TypeOf(defaultValue).Kind() != reflect.Ptr ||
+				reflect.TypeOf(defaultValue).Elem() != bigIntType {
+				panic("out points to big.Int, but defaultValue does not")
+			}
+			out.(*big.Int).Set(defaultValue.(*big.Int))
+		default:
+			panic("invalid integer type")
+		}
+		return true
+	}
+	if !i.ReadASN1Integer(out) || !i.Empty() {
+		return false
+	}
+	return true
+}
+
+// ReadOptionalASN1OctetString attempts to read an optional ASN.1 OCTET STRING
+// explicitly tagged with tag into out and advances. If no element with a
+// matching tag is present, it sets "out" to nil instead. It reports
+// whether the read was successful.
+func (s *String) ReadOptionalASN1OctetString(out *[]byte, outPresent *bool, tag asn1.Tag) bool {
+	var present bool
+	var child String
+	if !s.ReadOptionalASN1(&child, &present, tag) {
+		return false
+	}
+	if outPresent != nil {
+		*outPresent = present
+	}
+	if present {
+		var oct String
+		if !child.ReadASN1(&oct, asn1.OCTET_STRING) || !child.Empty() {
+			return false
+		}
+		*out = oct
+	} else {
+		*out = nil
+	}
+	return true
+}
+
+// ReadOptionalASN1Boolean sets *out to the value of the next ASN.1 BOOLEAN or,
+// if the next bytes are not an ASN.1 BOOLEAN, to the value of defaultValue.
+// It reports whether the operation was successful.
+func (s *String) ReadOptionalASN1Boolean(out *bool, defaultValue bool) bool {
+	var present bool
+	var child String
+	if !s.ReadOptionalASN1(&child, &present, asn1.BOOLEAN) {
+		return false
+	}
+
+	if !present {
+		*out = defaultValue
+		return true
+	}
+
+	return s.ReadASN1Boolean(out)
+}
+
+func (s *String) readASN1(out *String, outTag *asn1.Tag, skipHeader bool) bool {
+	if len(*s) < 2 {
+		return false
+	}
+	tag, lenByte := (*s)[0], (*s)[1]
+
+	if tag&0x1f == 0x1f {
+		// ITU-T X.690 section 8.1.2
+		//
+		// An identifier octet with a tag part of 0x1f indicates a high-tag-number
+		// form identifier with two or more octets. We only support tags less than
+		// 31 (i.e. low-tag-number form, single octet identifier).
+		return false
+	}
+
+	if outTag != nil {
+		*outTag = asn1.Tag(tag)
+	}
+
+	// ITU-T X.690 section 8.1.3
+	//
+	// Bit 8 of the first length byte indicates whether the length is short- or
+	// long-form.
+	var length, headerLen uint32 // length includes headerLen
+	if lenByte&0x80 == 0 {
+		// Short-form length (section 8.1.3.4), encoded in bits 1-7.
+		length = uint32(lenByte) + 2
+		headerLen = 2
+	} else {
+		// Long-form length (section 8.1.3.5). Bits 1-7 encode the number of octets
+		// used to encode the length.
+		lenLen := lenByte & 0x7f
+		var len32 uint32
+
+		if lenLen == 0 || lenLen > 4 || len(*s) < int(2+lenLen) {
+			return false
+		}
+
+		lenBytes := String((*s)[2 : 2+lenLen])
+		if !lenBytes.readUnsigned(&len32, int(lenLen)) {
+			return false
+		}
+
+		// ITU-T X.690 section 10.1 (DER length forms) requires encoding the length
+		// with the minimum number of octets.
+		if len32 < 128 {
+			// Length should have used short-form encoding.
+			return false
+		}
+		if len32>>((lenLen-1)*8) == 0 {
+			// Leading octet is 0. Length should have been at least one byte shorter.
+			return false
+		}
+
+		headerLen = 2 + uint32(lenLen)
+		if headerLen+len32 < len32 {
+			// Overflow.
+			return false
+		}
+		length = headerLen + len32
+	}
+
+	if int(length) < 0 || !s.ReadBytes((*[]byte)(out), int(length)) {
+		return false
+	}
+	if skipHeader && !out.Skip(int(headerLen)) {
+		panic("cryptobyte: internal error")
+	}
+
+	return true
+}
diff --git a/vendor/golang.org/x/crypto/cryptobyte/asn1/asn1.go b/vendor/golang.org/x/crypto/cryptobyte/asn1/asn1.go
new file mode 100644
index 0000000000..cda8e3edfd
--- /dev/null
+++ b/vendor/golang.org/x/crypto/cryptobyte/asn1/asn1.go
@@ -0,0 +1,46 @@
+// Copyright 2017 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 asn1 contains supporting types for parsing and building ASN.1
+// messages with the cryptobyte package.
+package asn1 // import "golang.org/x/crypto/cryptobyte/asn1"
+
+// Tag represents an ASN.1 identifier octet, consisting of a tag number
+// (indicating a type) and class (such as context-specific or constructed).
+//
+// Methods in the cryptobyte package only support the low-tag-number form, i.e.
+// a single identifier octet with bits 7-8 encoding the class and bits 1-6
+// encoding the tag number.
+type Tag uint8
+
+const (
+	classConstructed     = 0x20
+	classContextSpecific = 0x80
+)
+
+// Constructed returns t with the constructed class bit set.
+func (t Tag) Constructed() Tag { return t | classConstructed }
+
+// ContextSpecific returns t with the context-specific class bit set.
+func (t Tag) ContextSpecific() Tag { return t | classContextSpecific }
+
+// The following is a list of standard tag and class combinations.
+const (
+	BOOLEAN           = Tag(1)
+	INTEGER           = Tag(2)
+	BIT_STRING        = Tag(3)
+	OCTET_STRING      = Tag(4)
+	NULL              = Tag(5)
+	OBJECT_IDENTIFIER = Tag(6)
+	ENUM              = Tag(10)
+	UTF8String        = Tag(12)
+	SEQUENCE          = Tag(16 | classConstructed)
+	SET               = Tag(17 | classConstructed)
+	PrintableString   = Tag(19)
+	T61String         = Tag(20)
+	IA5String         = Tag(22)
+	UTCTime           = Tag(23)
+	GeneralizedTime   = Tag(24)
+	GeneralString     = Tag(27)
+)
diff --git a/vendor/golang.org/x/crypto/cryptobyte/builder.go b/vendor/golang.org/x/crypto/cryptobyte/builder.go
new file mode 100644
index 0000000000..ca7b1db5ce
--- /dev/null
+++ b/vendor/golang.org/x/crypto/cryptobyte/builder.go
@@ -0,0 +1,337 @@
+// Copyright 2017 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 cryptobyte
+
+import (
+	"errors"
+	"fmt"
+)
+
+// A Builder builds byte strings from fixed-length and length-prefixed values.
+// Builders either allocate space as needed, or are ‘fixed’, which means that
+// they write into a given buffer and produce an error if it's exhausted.
+//
+// The zero value is a usable Builder that allocates space as needed.
+//
+// Simple values are marshaled and appended to a Builder using methods on the
+// Builder. Length-prefixed values are marshaled by providing a
+// BuilderContinuation, which is a function that writes the inner contents of
+// the value to a given Builder. See the documentation for BuilderContinuation
+// for details.
+type Builder struct {
+	err            error
+	result         []byte
+	fixedSize      bool
+	child          *Builder
+	offset         int
+	pendingLenLen  int
+	pendingIsASN1  bool
+	inContinuation *bool
+}
+
+// NewBuilder creates a Builder that appends its output to the given buffer.
+// Like append(), the slice will be reallocated if its capacity is exceeded.
+// Use Bytes to get the final buffer.
+func NewBuilder(buffer []byte) *Builder {
+	return &Builder{
+		result: buffer,
+	}
+}
+
+// NewFixedBuilder creates a Builder that appends its output into the given
+// buffer. This builder does not reallocate the output buffer. Writes that
+// would exceed the buffer's capacity are treated as an error.
+func NewFixedBuilder(buffer []byte) *Builder {
+	return &Builder{
+		result:    buffer,
+		fixedSize: true,
+	}
+}
+
+// SetError sets the value to be returned as the error from Bytes. Writes
+// performed after calling SetError are ignored.
+func (b *Builder) SetError(err error) {
+	b.err = err
+}
+
+// Bytes returns the bytes written by the builder or an error if one has
+// occurred during building.
+func (b *Builder) Bytes() ([]byte, error) {
+	if b.err != nil {
+		return nil, b.err
+	}
+	return b.result[b.offset:], nil
+}
+
+// BytesOrPanic returns the bytes written by the builder or panics if an error
+// has occurred during building.
+func (b *Builder) BytesOrPanic() []byte {
+	if b.err != nil {
+		panic(b.err)
+	}
+	return b.result[b.offset:]
+}
+
+// AddUint8 appends an 8-bit value to the byte string.
+func (b *Builder) AddUint8(v uint8) {
+	b.add(byte(v))
+}
+
+// AddUint16 appends a big-endian, 16-bit value to the byte string.
+func (b *Builder) AddUint16(v uint16) {
+	b.add(byte(v>>8), byte(v))
+}
+
+// AddUint24 appends a big-endian, 24-bit value to the byte string. The highest
+// byte of the 32-bit input value is silently truncated.
+func (b *Builder) AddUint24(v uint32) {
+	b.add(byte(v>>16), byte(v>>8), byte(v))
+}
+
+// AddUint32 appends a big-endian, 32-bit value to the byte string.
+func (b *Builder) AddUint32(v uint32) {
+	b.add(byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
+}
+
+// AddBytes appends a sequence of bytes to the byte string.
+func (b *Builder) AddBytes(v []byte) {
+	b.add(v...)
+}
+
+// BuilderContinuation is a continuation-passing interface for building
+// length-prefixed byte sequences. Builder methods for length-prefixed
+// sequences (AddUint8LengthPrefixed etc) will invoke the BuilderContinuation
+// supplied to them. The child builder passed to the continuation can be used
+// to build the content of the length-prefixed sequence. For example:
+//
+//   parent := cryptobyte.NewBuilder()
+//   parent.AddUint8LengthPrefixed(func (child *Builder) {
+//     child.AddUint8(42)
+//     child.AddUint8LengthPrefixed(func (grandchild *Builder) {
+//       grandchild.AddUint8(5)
+//     })
+//   })
+//
+// It is an error to write more bytes to the child than allowed by the reserved
+// length prefix. After the continuation returns, the child must be considered
+// invalid, i.e. users must not store any copies or references of the child
+// that outlive the continuation.
+//
+// If the continuation panics with a value of type BuildError then the inner
+// error will be returned as the error from Bytes. If the child panics
+// otherwise then Bytes will repanic with the same value.
+type BuilderContinuation func(child *Builder)
+
+// BuildError wraps an error. If a BuilderContinuation panics with this value,
+// the panic will be recovered and the inner error will be returned from
+// Builder.Bytes.
+type BuildError struct {
+	Err error
+}
+
+// AddUint8LengthPrefixed adds a 8-bit length-prefixed byte sequence.
+func (b *Builder) AddUint8LengthPrefixed(f BuilderContinuation) {
+	b.addLengthPrefixed(1, false, f)
+}
+
+// AddUint16LengthPrefixed adds a big-endian, 16-bit length-prefixed byte sequence.
+func (b *Builder) AddUint16LengthPrefixed(f BuilderContinuation) {
+	b.addLengthPrefixed(2, false, f)
+}
+
+// AddUint24LengthPrefixed adds a big-endian, 24-bit length-prefixed byte sequence.
+func (b *Builder) AddUint24LengthPrefixed(f BuilderContinuation) {
+	b.addLengthPrefixed(3, false, f)
+}
+
+// AddUint32LengthPrefixed adds a big-endian, 32-bit length-prefixed byte sequence.
+func (b *Builder) AddUint32LengthPrefixed(f BuilderContinuation) {
+	b.addLengthPrefixed(4, false, f)
+}
+
+func (b *Builder) callContinuation(f BuilderContinuation, arg *Builder) {
+	if !*b.inContinuation {
+		*b.inContinuation = true
+
+		defer func() {
+			*b.inContinuation = false
+
+			r := recover()
+			if r == nil {
+				return
+			}
+
+			if buildError, ok := r.(BuildError); ok {
+				b.err = buildError.Err
+			} else {
+				panic(r)
+			}
+		}()
+	}
+
+	f(arg)
+}
+
+func (b *Builder) addLengthPrefixed(lenLen int, isASN1 bool, f BuilderContinuation) {
+	// Subsequent writes can be ignored if the builder has encountered an error.
+	if b.err != nil {
+		return
+	}
+
+	offset := len(b.result)
+	b.add(make([]byte, lenLen)...)
+
+	if b.inContinuation == nil {
+		b.inContinuation = new(bool)
+	}
+
+	b.child = &Builder{
+		result:         b.result,
+		fixedSize:      b.fixedSize,
+		offset:         offset,
+		pendingLenLen:  lenLen,
+		pendingIsASN1:  isASN1,
+		inContinuation: b.inContinuation,
+	}
+
+	b.callContinuation(f, b.child)
+	b.flushChild()
+	if b.child != nil {
+		panic("cryptobyte: internal error")
+	}
+}
+
+func (b *Builder) flushChild() {
+	if b.child == nil {
+		return
+	}
+	b.child.flushChild()
+	child := b.child
+	b.child = nil
+
+	if child.err != nil {
+		b.err = child.err
+		return
+	}
+
+	length := len(child.result) - child.pendingLenLen - child.offset
+
+	if length < 0 {
+		panic("cryptobyte: internal error") // result unexpectedly shrunk
+	}
+
+	if child.pendingIsASN1 {
+		// For ASN.1, we reserved a single byte for the length. If that turned out
+		// to be incorrect, we have to move the contents along in order to make
+		// space.
+		if child.pendingLenLen != 1 {
+			panic("cryptobyte: internal error")
+		}
+		var lenLen, lenByte uint8
+		if int64(length) > 0xfffffffe {
+			b.err = errors.New("pending ASN.1 child too long")
+			return
+		} else if length > 0xffffff {
+			lenLen = 5
+			lenByte = 0x80 | 4
+		} else if length > 0xffff {
+			lenLen = 4
+			lenByte = 0x80 | 3
+		} else if length > 0xff {
+			lenLen = 3
+			lenByte = 0x80 | 2
+		} else if length > 0x7f {
+			lenLen = 2
+			lenByte = 0x80 | 1
+		} else {
+			lenLen = 1
+			lenByte = uint8(length)
+			length = 0
+		}
+
+		// Insert the initial length byte, make space for successive length bytes,
+		// and adjust the offset.
+		child.result[child.offset] = lenByte
+		extraBytes := int(lenLen - 1)
+		if extraBytes != 0 {
+			child.add(make([]byte, extraBytes)...)
+			childStart := child.offset + child.pendingLenLen
+			copy(child.result[childStart+extraBytes:], child.result[childStart:])
+		}
+		child.offset++
+		child.pendingLenLen = extraBytes
+	}
+
+	l := length
+	for i := child.pendingLenLen - 1; i >= 0; i-- {
+		child.result[child.offset+i] = uint8(l)
+		l >>= 8
+	}
+	if l != 0 {
+		b.err = fmt.Errorf("cryptobyte: pending child length %d exceeds %d-byte length prefix", length, child.pendingLenLen)
+		return
+	}
+
+	if b.fixedSize && &b.result[0] != &child.result[0] {
+		panic("cryptobyte: BuilderContinuation reallocated a fixed-size buffer")
+	}
+
+	b.result = child.result
+}
+
+func (b *Builder) add(bytes ...byte) {
+	if b.err != nil {
+		return
+	}
+	if b.child != nil {
+		panic("cryptobyte: attempted write while child is pending")
+	}
+	if len(b.result)+len(bytes) < len(bytes) {
+		b.err = errors.New("cryptobyte: length overflow")
+	}
+	if b.fixedSize && len(b.result)+len(bytes) > cap(b.result) {
+		b.err = errors.New("cryptobyte: Builder is exceeding its fixed-size buffer")
+		return
+	}
+	b.result = append(b.result, bytes...)
+}
+
+// Unwrite rolls back n bytes written directly to the Builder. An attempt by a
+// child builder passed to a continuation to unwrite bytes from its parent will
+// panic.
+func (b *Builder) Unwrite(n int) {
+	if b.err != nil {
+		return
+	}
+	if b.child != nil {
+		panic("cryptobyte: attempted unwrite while child is pending")
+	}
+	length := len(b.result) - b.pendingLenLen - b.offset
+	if length < 0 {
+		panic("cryptobyte: internal error")
+	}
+	if n > length {
+		panic("cryptobyte: attempted to unwrite more than was written")
+	}
+	b.result = b.result[:len(b.result)-n]
+}
+
+// A MarshalingValue marshals itself into a Builder.
+type MarshalingValue interface {
+	// Marshal is called by Builder.AddValue. It receives a pointer to a builder
+	// to marshal itself into. It may return an error that occurred during
+	// marshaling, such as unset or invalid values.
+	Marshal(b *Builder) error
+}
+
+// AddValue calls Marshal on v, passing a pointer to the builder to append to.
+// If Marshal returns an error, it is set on the Builder so that subsequent
+// appends don't have an effect.
+func (b *Builder) AddValue(v MarshalingValue) {
+	err := v.Marshal(b)
+	if err != nil {
+		b.err = err
+	}
+}
diff --git a/vendor/golang.org/x/crypto/cryptobyte/string.go b/vendor/golang.org/x/crypto/cryptobyte/string.go
new file mode 100644
index 0000000000..589d297e6b
--- /dev/null
+++ b/vendor/golang.org/x/crypto/cryptobyte/string.go
@@ -0,0 +1,161 @@
+// Copyright 2017 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 cryptobyte contains types that help with parsing and constructing
+// length-prefixed, binary messages, including ASN.1 DER. (The asn1 subpackage
+// contains useful ASN.1 constants.)
+//
+// The String type is for parsing. It wraps a []byte slice and provides helper
+// functions for consuming structures, value by value.
+//
+// The Builder type is for constructing messages. It providers helper functions
+// for appending values and also for appending length-prefixed submessages –
+// without having to worry about calculating the length prefix ahead of time.
+//
+// See the documentation and examples for the Builder and String types to get
+// started.
+package cryptobyte // import "golang.org/x/crypto/cryptobyte"
+
+// String represents a string of bytes. It provides methods for parsing
+// fixed-length and length-prefixed values from it.
+type String []byte
+
+// read advances a String by n bytes and returns them. If less than n bytes
+// remain, it returns nil.
+func (s *String) read(n int) []byte {
+	if len(*s) < n || n < 0 {
+		return nil
+	}
+	v := (*s)[:n]
+	*s = (*s)[n:]
+	return v
+}
+
+// Skip advances the String by n byte and reports whether it was successful.
+func (s *String) Skip(n int) bool {
+	return s.read(n) != nil
+}
+
+// ReadUint8 decodes an 8-bit value into out and advances over it.
+// It reports whether the read was successful.
+func (s *String) ReadUint8(out *uint8) bool {
+	v := s.read(1)
+	if v == nil {
+		return false
+	}
+	*out = uint8(v[0])
+	return true
+}
+
+// ReadUint16 decodes a big-endian, 16-bit value into out and advances over it.
+// It reports whether the read was successful.
+func (s *String) ReadUint16(out *uint16) bool {
+	v := s.read(2)
+	if v == nil {
+		return false
+	}
+	*out = uint16(v[0])<<8 | uint16(v[1])
+	return true
+}
+
+// ReadUint24 decodes a big-endian, 24-bit value into out and advances over it.
+// It reports whether the read was successful.
+func (s *String) ReadUint24(out *uint32) bool {
+	v := s.read(3)
+	if v == nil {
+		return false
+	}
+	*out = uint32(v[0])<<16 | uint32(v[1])<<8 | uint32(v[2])
+	return true
+}
+
+// ReadUint32 decodes a big-endian, 32-bit value into out and advances over it.
+// It reports whether the read was successful.
+func (s *String) ReadUint32(out *uint32) bool {
+	v := s.read(4)
+	if v == nil {
+		return false
+	}
+	*out = uint32(v[0])<<24 | uint32(v[1])<<16 | uint32(v[2])<<8 | uint32(v[3])
+	return true
+}
+
+func (s *String) readUnsigned(out *uint32, length int) bool {
+	v := s.read(length)
+	if v == nil {
+		return false
+	}
+	var result uint32
+	for i := 0; i < length; i++ {
+		result <<= 8
+		result |= uint32(v[i])
+	}
+	*out = result
+	return true
+}
+
+func (s *String) readLengthPrefixed(lenLen int, outChild *String) bool {
+	lenBytes := s.read(lenLen)
+	if lenBytes == nil {
+		return false
+	}
+	var length uint32
+	for _, b := range lenBytes {
+		length = length << 8
+		length = length | uint32(b)
+	}
+	v := s.read(int(length))
+	if v == nil {
+		return false
+	}
+	*outChild = v
+	return true
+}
+
+// ReadUint8LengthPrefixed reads the content of an 8-bit length-prefixed value
+// into out and advances over it. It reports whether the read was successful.
+func (s *String) ReadUint8LengthPrefixed(out *String) bool {
+	return s.readLengthPrefixed(1, out)
+}
+
+// ReadUint16LengthPrefixed reads the content of a big-endian, 16-bit
+// length-prefixed value into out and advances over it. It reports whether the
+// read was successful.
+func (s *String) ReadUint16LengthPrefixed(out *String) bool {
+	return s.readLengthPrefixed(2, out)
+}
+
+// ReadUint24LengthPrefixed reads the content of a big-endian, 24-bit
+// length-prefixed value into out and advances over it. It reports whether
+// the read was successful.
+func (s *String) ReadUint24LengthPrefixed(out *String) bool {
+	return s.readLengthPrefixed(3, out)
+}
+
+// ReadBytes reads n bytes into out and advances over them. It reports
+// whether the read was successful.
+func (s *String) ReadBytes(out *[]byte, n int) bool {
+	v := s.read(n)
+	if v == nil {
+		return false
+	}
+	*out = v
+	return true
+}
+
+// CopyBytes copies len(out) bytes into out and advances over them. It reports
+// whether the copy operation was successful
+func (s *String) CopyBytes(out []byte) bool {
+	n := len(out)
+	v := s.read(n)
+	if v == nil {
+		return false
+	}
+	return copy(out, v) == n
+}
+
+// Empty reports whether the string does not contain any bytes.
+func (s String) Empty() bool {
+	return len(s) == 0
+}
diff --git a/vendor/golang.org/x/crypto/pkcs12/bmp-string.go b/vendor/golang.org/x/crypto/pkcs12/bmp-string.go
new file mode 100644
index 0000000000..233b8b62cc
--- /dev/null
+++ b/vendor/golang.org/x/crypto/pkcs12/bmp-string.go
@@ -0,0 +1,50 @@
+// 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 (
+	"errors"
+	"unicode/utf16"
+)
+
+// bmpString returns s encoded in UCS-2 with a zero terminator.
+func bmpString(s string) ([]byte, error) {
+	// References:
+	// https://tools.ietf.org/html/rfc7292#appendix-B.1
+	// https://en.wikipedia.org/wiki/Plane_(Unicode)#Basic_Multilingual_Plane
+	//  - non-BMP characters are encoded in UTF 16 by using a surrogate pair of 16-bit codes
+	//	  EncodeRune returns 0xfffd if the rune does not need special encoding
+	//  - the above RFC provides the info that BMPStrings are NULL terminated.
+
+	ret := make([]byte, 0, 2*len(s)+2)
+
+	for _, r := range s {
+		if t, _ := utf16.EncodeRune(r); t != 0xfffd {
+			return nil, errors.New("pkcs12: string contains characters that cannot be encoded in UCS-2")
+		}
+		ret = append(ret, byte(r/256), byte(r%256))
+	}
+
+	return append(ret, 0, 0), nil
+}
+
+func decodeBMPString(bmpString []byte) (string, error) {
+	if len(bmpString)%2 != 0 {
+		return "", errors.New("pkcs12: odd-length BMP string")
+	}
+
+	// strip terminator if present
+	if l := len(bmpString); l >= 2 && bmpString[l-1] == 0 && bmpString[l-2] == 0 {
+		bmpString = bmpString[:l-2]
+	}
+
+	s := make([]uint16, 0, len(bmpString)/2)
+	for len(bmpString) > 0 {
+		s = append(s, uint16(bmpString[0])<<8+uint16(bmpString[1]))
+		bmpString = bmpString[2:]
+	}
+
+	return string(utf16.Decode(s)), nil
+}
diff --git a/vendor/golang.org/x/crypto/pkcs12/crypto.go b/vendor/golang.org/x/crypto/pkcs12/crypto.go
new file mode 100644
index 0000000000..484ca51b71
--- /dev/null
+++ b/vendor/golang.org/x/crypto/pkcs12/crypto.go
@@ -0,0 +1,131 @@
+// 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 (
+	"bytes"
+	"crypto/cipher"
+	"crypto/des"
+	"crypto/x509/pkix"
+	"encoding/asn1"
+	"errors"
+
+	"golang.org/x/crypto/pkcs12/internal/rc2"
+)
+
+var (
+	oidPBEWithSHAAnd3KeyTripleDESCBC = asn1.ObjectIdentifier([]int{1, 2, 840, 113549, 1, 12, 1, 3})
+	oidPBEWithSHAAnd40BitRC2CBC      = asn1.ObjectIdentifier([]int{1, 2, 840, 113549, 1, 12, 1, 6})
+)
+
+// pbeCipher is an abstraction of a PKCS#12 cipher.
+type pbeCipher interface {
+	// create returns a cipher.Block given a key.
+	create(key []byte) (cipher.Block, error)
+	// deriveKey returns a key derived from the given password and salt.
+	deriveKey(salt, password []byte, iterations int) []byte
+	// deriveKey returns an IV derived from the given password and salt.
+	deriveIV(salt, password []byte, iterations int) []byte
+}
+
+type shaWithTripleDESCBC struct{}
+
+func (shaWithTripleDESCBC) create(key []byte) (cipher.Block, error) {
+	return des.NewTripleDESCipher(key)
+}
+
+func (shaWithTripleDESCBC) deriveKey(salt, password []byte, iterations int) []byte {
+	return pbkdf(sha1Sum, 20, 64, salt, password, iterations, 1, 24)
+}
+
+func (shaWithTripleDESCBC) deriveIV(salt, password []byte, iterations int) []byte {
+	return pbkdf(sha1Sum, 20, 64, salt, password, iterations, 2, 8)
+}
+
+type shaWith40BitRC2CBC struct{}
+
+func (shaWith40BitRC2CBC) create(key []byte) (cipher.Block, error) {
+	return rc2.New(key, len(key)*8)
+}
+
+func (shaWith40BitRC2CBC) deriveKey(salt, password []byte, iterations int) []byte {
+	return pbkdf(sha1Sum, 20, 64, salt, password, iterations, 1, 5)
+}
+
+func (shaWith40BitRC2CBC) deriveIV(salt, password []byte, iterations int) []byte {
+	return pbkdf(sha1Sum, 20, 64, salt, password, iterations, 2, 8)
+}
+
+type pbeParams struct {
+	Salt       []byte
+	Iterations int
+}
+
+func pbDecrypterFor(algorithm pkix.AlgorithmIdentifier, password []byte) (cipher.BlockMode, int, error) {
+	var cipherType pbeCipher
+
+	switch {
+	case algorithm.Algorithm.Equal(oidPBEWithSHAAnd3KeyTripleDESCBC):
+		cipherType = shaWithTripleDESCBC{}
+	case algorithm.Algorithm.Equal(oidPBEWithSHAAnd40BitRC2CBC):
+		cipherType = shaWith40BitRC2CBC{}
+	default:
+		return nil, 0, NotImplementedError("algorithm " + algorithm.Algorithm.String() + " is not supported")
+	}
+
+	var params pbeParams
+	if err := unmarshal(algorithm.Parameters.FullBytes, &params); err != nil {
+		return nil, 0, err
+	}
+
+	key := cipherType.deriveKey(params.Salt, password, params.Iterations)
+	iv := cipherType.deriveIV(params.Salt, password, params.Iterations)
+
+	block, err := cipherType.create(key)
+	if err != nil {
+		return nil, 0, err
+	}
+
+	return cipher.NewCBCDecrypter(block, iv), block.BlockSize(), nil
+}
+
+func pbDecrypt(info decryptable, password []byte) (decrypted []byte, err error) {
+	cbc, blockSize, err := pbDecrypterFor(info.Algorithm(), password)
+	if err != nil {
+		return nil, err
+	}
+
+	encrypted := info.Data()
+	if len(encrypted) == 0 {
+		return nil, errors.New("pkcs12: empty encrypted data")
+	}
+	if len(encrypted)%blockSize != 0 {
+		return nil, errors.New("pkcs12: input is not a multiple of the block size")
+	}
+	decrypted = make([]byte, len(encrypted))
+	cbc.CryptBlocks(decrypted, encrypted)
+
+	psLen := int(decrypted[len(decrypted)-1])
+	if psLen == 0 || psLen > blockSize {
+		return nil, ErrDecryption
+	}
+
+	if len(decrypted) < psLen {
+		return nil, ErrDecryption
+	}
+	ps := decrypted[len(decrypted)-psLen:]
+	decrypted = decrypted[:len(decrypted)-psLen]
+	if bytes.Compare(ps, bytes.Repeat([]byte{byte(psLen)}, psLen)) != 0 {
+		return nil, ErrDecryption
+	}
+
+	return
+}
+
+// decryptable abstracts an object that contains ciphertext.
+type decryptable interface {
+	Algorithm() pkix.AlgorithmIdentifier
+	Data() []byte
+}
diff --git a/vendor/golang.org/x/crypto/pkcs12/errors.go b/vendor/golang.org/x/crypto/pkcs12/errors.go
new file mode 100644
index 0000000000..7377ce6fb2
--- /dev/null
+++ b/vendor/golang.org/x/crypto/pkcs12/errors.go
@@ -0,0 +1,23 @@
+// 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 "errors"
+
+var (
+	// ErrDecryption represents a failure to decrypt the input.
+	ErrDecryption = errors.New("pkcs12: decryption error, incorrect padding")
+
+	// ErrIncorrectPassword is returned when an incorrect password is detected.
+	// Usually, P12/PFX data is signed to be able to verify the password.
+	ErrIncorrectPassword = errors.New("pkcs12: decryption password incorrect")
+)
+
+// NotImplementedError indicates that the input is not currently supported.
+type NotImplementedError string
+
+func (e NotImplementedError) Error() string {
+	return "pkcs12: " + string(e)
+}
diff --git a/vendor/golang.org/x/crypto/pkcs12/internal/rc2/rc2.go b/vendor/golang.org/x/crypto/pkcs12/internal/rc2/rc2.go
new file mode 100644
index 0000000000..7499e3fb69
--- /dev/null
+++ b/vendor/golang.org/x/crypto/pkcs12/internal/rc2/rc2.go
@@ -0,0 +1,271 @@
+// 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 rc2 implements the RC2 cipher
+/*
+https://www.ietf.org/rfc/rfc2268.txt
+http://people.csail.mit.edu/rivest/pubs/KRRR98.pdf
+
+This code is licensed under the MIT license.
+*/
+package rc2
+
+import (
+	"crypto/cipher"
+	"encoding/binary"
+)
+
+// The rc2 block size in bytes
+const BlockSize = 8
+
+type rc2Cipher struct {
+	k [64]uint16
+}
+
+// New returns a new rc2 cipher with the given key and effective key length t1
+func New(key []byte, t1 int) (cipher.Block, error) {
+	// TODO(dgryski): error checking for key length
+	return &rc2Cipher{
+		k: expandKey(key, t1),
+	}, nil
+}
+
+func (*rc2Cipher) BlockSize() int { return BlockSize }
+
+var piTable = [256]byte{
+	0xd9, 0x78, 0xf9, 0xc4, 0x19, 0xdd, 0xb5, 0xed, 0x28, 0xe9, 0xfd, 0x79, 0x4a, 0xa0, 0xd8, 0x9d,
+	0xc6, 0x7e, 0x37, 0x83, 0x2b, 0x76, 0x53, 0x8e, 0x62, 0x4c, 0x64, 0x88, 0x44, 0x8b, 0xfb, 0xa2,
+	0x17, 0x9a, 0x59, 0xf5, 0x87, 0xb3, 0x4f, 0x13, 0x61, 0x45, 0x6d, 0x8d, 0x09, 0x81, 0x7d, 0x32,
+	0xbd, 0x8f, 0x40, 0xeb, 0x86, 0xb7, 0x7b, 0x0b, 0xf0, 0x95, 0x21, 0x22, 0x5c, 0x6b, 0x4e, 0x82,
+	0x54, 0xd6, 0x65, 0x93, 0xce, 0x60, 0xb2, 0x1c, 0x73, 0x56, 0xc0, 0x14, 0xa7, 0x8c, 0xf1, 0xdc,
+	0x12, 0x75, 0xca, 0x1f, 0x3b, 0xbe, 0xe4, 0xd1, 0x42, 0x3d, 0xd4, 0x30, 0xa3, 0x3c, 0xb6, 0x26,
+	0x6f, 0xbf, 0x0e, 0xda, 0x46, 0x69, 0x07, 0x57, 0x27, 0xf2, 0x1d, 0x9b, 0xbc, 0x94, 0x43, 0x03,
+	0xf8, 0x11, 0xc7, 0xf6, 0x90, 0xef, 0x3e, 0xe7, 0x06, 0xc3, 0xd5, 0x2f, 0xc8, 0x66, 0x1e, 0xd7,
+	0x08, 0xe8, 0xea, 0xde, 0x80, 0x52, 0xee, 0xf7, 0x84, 0xaa, 0x72, 0xac, 0x35, 0x4d, 0x6a, 0x2a,
+	0x96, 0x1a, 0xd2, 0x71, 0x5a, 0x15, 0x49, 0x74, 0x4b, 0x9f, 0xd0, 0x5e, 0x04, 0x18, 0xa4, 0xec,
+	0xc2, 0xe0, 0x41, 0x6e, 0x0f, 0x51, 0xcb, 0xcc, 0x24, 0x91, 0xaf, 0x50, 0xa1, 0xf4, 0x70, 0x39,
+	0x99, 0x7c, 0x3a, 0x85, 0x23, 0xb8, 0xb4, 0x7a, 0xfc, 0x02, 0x36, 0x5b, 0x25, 0x55, 0x97, 0x31,
+	0x2d, 0x5d, 0xfa, 0x98, 0xe3, 0x8a, 0x92, 0xae, 0x05, 0xdf, 0x29, 0x10, 0x67, 0x6c, 0xba, 0xc9,
+	0xd3, 0x00, 0xe6, 0xcf, 0xe1, 0x9e, 0xa8, 0x2c, 0x63, 0x16, 0x01, 0x3f, 0x58, 0xe2, 0x89, 0xa9,
+	0x0d, 0x38, 0x34, 0x1b, 0xab, 0x33, 0xff, 0xb0, 0xbb, 0x48, 0x0c, 0x5f, 0xb9, 0xb1, 0xcd, 0x2e,
+	0xc5, 0xf3, 0xdb, 0x47, 0xe5, 0xa5, 0x9c, 0x77, 0x0a, 0xa6, 0x20, 0x68, 0xfe, 0x7f, 0xc1, 0xad,
+}
+
+func expandKey(key []byte, t1 int) [64]uint16 {
+
+	l := make([]byte, 128)
+	copy(l, key)
+
+	var t = len(key)
+	var t8 = (t1 + 7) / 8
+	var tm = byte(255 % uint(1<<(8+uint(t1)-8*uint(t8))))
+
+	for i := len(key); i < 128; i++ {
+		l[i] = piTable[l[i-1]+l[uint8(i-t)]]
+	}
+
+	l[128-t8] = piTable[l[128-t8]&tm]
+
+	for i := 127 - t8; i >= 0; i-- {
+		l[i] = piTable[l[i+1]^l[i+t8]]
+	}
+
+	var k [64]uint16
+
+	for i := range k {
+		k[i] = uint16(l[2*i]) + uint16(l[2*i+1])*256
+	}
+
+	return k
+}
+
+func rotl16(x uint16, b uint) uint16 {
+	return (x >> (16 - b)) | (x << b)
+}
+
+func (c *rc2Cipher) Encrypt(dst, src []byte) {
+
+	r0 := binary.LittleEndian.Uint16(src[0:])
+	r1 := binary.LittleEndian.Uint16(src[2:])
+	r2 := binary.LittleEndian.Uint16(src[4:])
+	r3 := binary.LittleEndian.Uint16(src[6:])
+
+	var j int
+
+	for j <= 16 {
+		// mix r0
+		r0 = r0 + c.k[j] + (r3 & r2) + ((^r3) & r1)
+		r0 = rotl16(r0, 1)
+		j++
+
+		// mix r1
+		r1 = r1 + c.k[j] + (r0 & r3) + ((^r0) & r2)
+		r1 = rotl16(r1, 2)
+		j++
+
+		// mix r2
+		r2 = r2 + c.k[j] + (r1 & r0) + ((^r1) & r3)
+		r2 = rotl16(r2, 3)
+		j++
+
+		// mix r3
+		r3 = r3 + c.k[j] + (r2 & r1) + ((^r2) & r0)
+		r3 = rotl16(r3, 5)
+		j++
+
+	}
+
+	r0 = r0 + c.k[r3&63]
+	r1 = r1 + c.k[r0&63]
+	r2 = r2 + c.k[r1&63]
+	r3 = r3 + c.k[r2&63]
+
+	for j <= 40 {
+		// mix r0
+		r0 = r0 + c.k[j] + (r3 & r2) + ((^r3) & r1)
+		r0 = rotl16(r0, 1)
+		j++
+
+		// mix r1
+		r1 = r1 + c.k[j] + (r0 & r3) + ((^r0) & r2)
+		r1 = rotl16(r1, 2)
+		j++
+
+		// mix r2
+		r2 = r2 + c.k[j] + (r1 & r0) + ((^r1) & r3)
+		r2 = rotl16(r2, 3)
+		j++
+
+		// mix r3
+		r3 = r3 + c.k[j] + (r2 & r1) + ((^r2) & r0)
+		r3 = rotl16(r3, 5)
+		j++
+
+	}
+
+	r0 = r0 + c.k[r3&63]
+	r1 = r1 + c.k[r0&63]
+	r2 = r2 + c.k[r1&63]
+	r3 = r3 + c.k[r2&63]
+
+	for j <= 60 {
+		// mix r0
+		r0 = r0 + c.k[j] + (r3 & r2) + ((^r3) & r1)
+		r0 = rotl16(r0, 1)
+		j++
+
+		// mix r1
+		r1 = r1 + c.k[j] + (r0 & r3) + ((^r0) & r2)
+		r1 = rotl16(r1, 2)
+		j++
+
+		// mix r2
+		r2 = r2 + c.k[j] + (r1 & r0) + ((^r1) & r3)
+		r2 = rotl16(r2, 3)
+		j++
+
+		// mix r3
+		r3 = r3 + c.k[j] + (r2 & r1) + ((^r2) & r0)
+		r3 = rotl16(r3, 5)
+		j++
+	}
+
+	binary.LittleEndian.PutUint16(dst[0:], r0)
+	binary.LittleEndian.PutUint16(dst[2:], r1)
+	binary.LittleEndian.PutUint16(dst[4:], r2)
+	binary.LittleEndian.PutUint16(dst[6:], r3)
+}
+
+func (c *rc2Cipher) Decrypt(dst, src []byte) {
+
+	r0 := binary.LittleEndian.Uint16(src[0:])
+	r1 := binary.LittleEndian.Uint16(src[2:])
+	r2 := binary.LittleEndian.Uint16(src[4:])
+	r3 := binary.LittleEndian.Uint16(src[6:])
+
+	j := 63
+
+	for j >= 44 {
+		// unmix r3
+		r3 = rotl16(r3, 16-5)
+		r3 = r3 - c.k[j] - (r2 & r1) - ((^r2) & r0)
+		j--
+
+		// unmix r2
+		r2 = rotl16(r2, 16-3)
+		r2 = r2 - c.k[j] - (r1 & r0) - ((^r1) & r3)
+		j--
+
+		// unmix r1
+		r1 = rotl16(r1, 16-2)
+		r1 = r1 - c.k[j] - (r0 & r3) - ((^r0) & r2)
+		j--
+
+		// unmix r0
+		r0 = rotl16(r0, 16-1)
+		r0 = r0 - c.k[j] - (r3 & r2) - ((^r3) & r1)
+		j--
+	}
+
+	r3 = r3 - c.k[r2&63]
+	r2 = r2 - c.k[r1&63]
+	r1 = r1 - c.k[r0&63]
+	r0 = r0 - c.k[r3&63]
+
+	for j >= 20 {
+		// unmix r3
+		r3 = rotl16(r3, 16-5)
+		r3 = r3 - c.k[j] - (r2 & r1) - ((^r2) & r0)
+		j--
+
+		// unmix r2
+		r2 = rotl16(r2, 16-3)
+		r2 = r2 - c.k[j] - (r1 & r0) - ((^r1) & r3)
+		j--
+
+		// unmix r1
+		r1 = rotl16(r1, 16-2)
+		r1 = r1 - c.k[j] - (r0 & r3) - ((^r0) & r2)
+		j--
+
+		// unmix r0
+		r0 = rotl16(r0, 16-1)
+		r0 = r0 - c.k[j] - (r3 & r2) - ((^r3) & r1)
+		j--
+
+	}
+
+	r3 = r3 - c.k[r2&63]
+	r2 = r2 - c.k[r1&63]
+	r1 = r1 - c.k[r0&63]
+	r0 = r0 - c.k[r3&63]
+
+	for j >= 0 {
+		// unmix r3
+		r3 = rotl16(r3, 16-5)
+		r3 = r3 - c.k[j] - (r2 & r1) - ((^r2) & r0)
+		j--
+
+		// unmix r2
+		r2 = rotl16(r2, 16-3)
+		r2 = r2 - c.k[j] - (r1 & r0) - ((^r1) & r3)
+		j--
+
+		// unmix r1
+		r1 = rotl16(r1, 16-2)
+		r1 = r1 - c.k[j] - (r0 & r3) - ((^r0) & r2)
+		j--
+
+		// unmix r0
+		r0 = rotl16(r0, 16-1)
+		r0 = r0 - c.k[j] - (r3 & r2) - ((^r3) & r1)
+		j--
+
+	}
+
+	binary.LittleEndian.PutUint16(dst[0:], r0)
+	binary.LittleEndian.PutUint16(dst[2:], r1)
+	binary.LittleEndian.PutUint16(dst[4:], r2)
+	binary.LittleEndian.PutUint16(dst[6:], r3)
+}
diff --git a/vendor/golang.org/x/crypto/pkcs12/mac.go b/vendor/golang.org/x/crypto/pkcs12/mac.go
new file mode 100644
index 0000000000..5f38aa7de8
--- /dev/null
+++ b/vendor/golang.org/x/crypto/pkcs12/mac.go
@@ -0,0 +1,45 @@
+// 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 (
+	"crypto/hmac"
+	"crypto/sha1"
+	"crypto/x509/pkix"
+	"encoding/asn1"
+)
+
+type macData struct {
+	Mac        digestInfo
+	MacSalt    []byte
+	Iterations int `asn1:"optional,default:1"`
+}
+
+// from PKCS#7:
+type digestInfo struct {
+	Algorithm pkix.AlgorithmIdentifier
+	Digest    []byte
+}
+
+var (
+	oidSHA1 = asn1.ObjectIdentifier([]int{1, 3, 14, 3, 2, 26})
+)
+
+func verifyMac(macData *macData, message, password []byte) error {
+	if !macData.Mac.Algorithm.Algorithm.Equal(oidSHA1) {
+		return NotImplementedError("unknown digest algorithm: " + macData.Mac.Algorithm.Algorithm.String())
+	}
+
+	key := pbkdf(sha1Sum, 20, 64, macData.MacSalt, password, macData.Iterations, 3, 20)
+
+	mac := hmac.New(sha1.New, key)
+	mac.Write(message)
+	expectedMAC := mac.Sum(nil)
+
+	if !hmac.Equal(macData.Mac.Digest, expectedMAC) {
+		return ErrIncorrectPassword
+	}
+	return nil
+}
diff --git a/vendor/golang.org/x/crypto/pkcs12/pbkdf.go b/vendor/golang.org/x/crypto/pkcs12/pbkdf.go
new file mode 100644
index 0000000000..5c419d41e3
--- /dev/null
+++ b/vendor/golang.org/x/crypto/pkcs12/pbkdf.go
@@ -0,0 +1,170 @@
+// 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 (
+	"bytes"
+	"crypto/sha1"
+	"math/big"
+)
+
+var (
+	one = big.NewInt(1)
+)
+
+// sha1Sum returns the SHA-1 hash of in.
+func sha1Sum(in []byte) []byte {
+	sum := sha1.Sum(in)
+	return sum[:]
+}
+
+// fillWithRepeats returns v*ceiling(len(pattern) / v) bytes consisting of
+// repeats of pattern.
+func fillWithRepeats(pattern []byte, v int) []byte {
+	if len(pattern) == 0 {
+		return nil
+	}
+	outputLen := v * ((len(pattern) + v - 1) / v)
+	return bytes.Repeat(pattern, (outputLen+len(pattern)-1)/len(pattern))[:outputLen]
+}
+
+func pbkdf(hash func([]byte) []byte, u, v int, salt, password []byte, r int, ID byte, size int) (key []byte) {
+	// implementation of https://tools.ietf.org/html/rfc7292#appendix-B.2 , RFC text verbatim in comments
+
+	//    Let H be a hash function built around a compression function f:
+
+	//       Z_2^u x Z_2^v -> Z_2^u
+
+	//    (that is, H has a chaining variable and output of length u bits, and
+	//    the message input to the compression function of H is v bits).  The
+	//    values for u and v are as follows:
+
+	//            HASH FUNCTION     VALUE u        VALUE v
+	//              MD2, MD5          128            512
+	//                SHA-1           160            512
+	//               SHA-224          224            512
+	//               SHA-256          256            512
+	//               SHA-384          384            1024
+	//               SHA-512          512            1024
+	//             SHA-512/224        224            1024
+	//             SHA-512/256        256            1024
+
+	//    Furthermore, let r be the iteration count.
+
+	//    We assume here that u and v are both multiples of 8, as are the
+	//    lengths of the password and salt strings (which we denote by p and s,
+	//    respectively) and the number n of pseudorandom bits required.  In
+	//    addition, u and v are of course non-zero.
+
+	//    For information on security considerations for MD5 [19], see [25] and
+	//    [1], and on those for MD2, see [18].
+
+	//    The following procedure can be used to produce pseudorandom bits for
+	//    a particular "purpose" that is identified by a byte called "ID".
+	//    This standard specifies 3 different values for the ID byte:
+
+	//    1.  If ID=1, then the pseudorandom bits being produced are to be used
+	//        as key material for performing encryption or decryption.
+
+	//    2.  If ID=2, then the pseudorandom bits being produced are to be used
+	//        as an IV (Initial Value) for encryption or decryption.
+
+	//    3.  If ID=3, then the pseudorandom bits being produced are to be used
+	//        as an integrity key for MACing.
+
+	//    1.  Construct a string, D (the "diversifier"), by concatenating v/8
+	//        copies of ID.
+	var D []byte
+	for i := 0; i < v; i++ {
+		D = append(D, ID)
+	}
+
+	//    2.  Concatenate copies of the salt together to create a string S of
+	//        length v(ceiling(s/v)) bits (the final copy of the salt may be
+	//        truncated to create S).  Note that if the salt is the empty
+	//        string, then so is S.
+
+	S := fillWithRepeats(salt, v)
+
+	//    3.  Concatenate copies of the password together to create a string P
+	//        of length v(ceiling(p/v)) bits (the final copy of the password
+	//        may be truncated to create P).  Note that if the password is the
+	//        empty string, then so is P.
+
+	P := fillWithRepeats(password, v)
+
+	//    4.  Set I=S||P to be the concatenation of S and P.
+	I := append(S, P...)
+
+	//    5.  Set c=ceiling(n/u).
+	c := (size + u - 1) / u
+
+	//    6.  For i=1, 2, ..., c, do the following:
+	A := make([]byte, c*20)
+	var IjBuf []byte
+	for i := 0; i < c; i++ {
+		//        A.  Set A2=H^r(D||I). (i.e., the r-th hash of D||1,
+		//            H(H(H(... H(D||I))))
+		Ai := hash(append(D, I...))
+		for j := 1; j < r; j++ {
+			Ai = hash(Ai)
+		}
+		copy(A[i*20:], Ai[:])
+
+		if i < c-1 { // skip on last iteration
+			// B.  Concatenate copies of Ai to create a string B of length v
+			//     bits (the final copy of Ai may be truncated to create B).
+			var B []byte
+			for len(B) < v {
+				B = append(B, Ai[:]...)
+			}
+			B = B[:v]
+
+			// C.  Treating I as a concatenation I_0, I_1, ..., I_(k-1) of v-bit
+			//     blocks, where k=ceiling(s/v)+ceiling(p/v), modify I by
+			//     setting I_j=(I_j+B+1) mod 2^v for each j.
+			{
+				Bbi := new(big.Int).SetBytes(B)
+				Ij := new(big.Int)
+
+				for j := 0; j < len(I)/v; j++ {
+					Ij.SetBytes(I[j*v : (j+1)*v])
+					Ij.Add(Ij, Bbi)
+					Ij.Add(Ij, one)
+					Ijb := Ij.Bytes()
+					// We expect Ijb to be exactly v bytes,
+					// if it is longer or shorter we must
+					// adjust it accordingly.
+					if len(Ijb) > v {
+						Ijb = Ijb[len(Ijb)-v:]
+					}
+					if len(Ijb) < v {
+						if IjBuf == nil {
+							IjBuf = make([]byte, v)
+						}
+						bytesShort := v - len(Ijb)
+						for i := 0; i < bytesShort; i++ {
+							IjBuf[i] = 0
+						}
+						copy(IjBuf[bytesShort:], Ijb)
+						Ijb = IjBuf
+					}
+					copy(I[j*v:(j+1)*v], Ijb)
+				}
+			}
+		}
+	}
+	//    7.  Concatenate A_1, A_2, ..., A_c together to form a pseudorandom
+	//        bit string, A.
+
+	//    8.  Use the first n bits of A as the output of this entire process.
+	return A[:size]
+
+	//    If the above process is being used to generate a DES key, the process
+	//    should be used to create 64 random bits, and the key's parity bits
+	//    should be set after the 64 bits have been produced.  Similar concerns
+	//    hold for 2-key and 3-key triple-DES keys, for CDMF keys, and for any
+	//    similar keys with parity bits "built into them".
+}
diff --git a/vendor/golang.org/x/crypto/pkcs12/pkcs12.go b/vendor/golang.org/x/crypto/pkcs12/pkcs12.go
new file mode 100644
index 0000000000..3a89bdb3e3
--- /dev/null
+++ b/vendor/golang.org/x/crypto/pkcs12/pkcs12.go
@@ -0,0 +1,360 @@
+// 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 implements some of PKCS#12.
+//
+// This implementation is distilled from https://tools.ietf.org/html/rfc7292
+// and referenced documents. It is intended for decoding P12/PFX-stored
+// certificates and keys for use with the crypto/tls package.
+//
+// This package is frozen. If it's missing functionality you need, consider
+// an alternative like software.sslmate.com/src/go-pkcs12.
+package pkcs12
+
+import (
+	"crypto/ecdsa"
+	"crypto/rsa"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/asn1"
+	"encoding/hex"
+	"encoding/pem"
+	"errors"
+)
+
+var (
+	oidDataContentType          = asn1.ObjectIdentifier([]int{1, 2, 840, 113549, 1, 7, 1})
+	oidEncryptedDataContentType = asn1.ObjectIdentifier([]int{1, 2, 840, 113549, 1, 7, 6})
+
+	oidFriendlyName     = asn1.ObjectIdentifier([]int{1, 2, 840, 113549, 1, 9, 20})
+	oidLocalKeyID       = asn1.ObjectIdentifier([]int{1, 2, 840, 113549, 1, 9, 21})
+	oidMicrosoftCSPName = asn1.ObjectIdentifier([]int{1, 3, 6, 1, 4, 1, 311, 17, 1})
+
+	errUnknownAttributeOID = errors.New("pkcs12: unknown attribute OID")
+)
+
+type pfxPdu struct {
+	Version  int
+	AuthSafe contentInfo
+	MacData  macData `asn1:"optional"`
+}
+
+type contentInfo struct {
+	ContentType asn1.ObjectIdentifier
+	Content     asn1.RawValue `asn1:"tag:0,explicit,optional"`
+}
+
+type encryptedData struct {
+	Version              int
+	EncryptedContentInfo encryptedContentInfo
+}
+
+type encryptedContentInfo struct {
+	ContentType                asn1.ObjectIdentifier
+	ContentEncryptionAlgorithm pkix.AlgorithmIdentifier
+	EncryptedContent           []byte `asn1:"tag:0,optional"`
+}
+
+func (i encryptedContentInfo) Algorithm() pkix.AlgorithmIdentifier {
+	return i.ContentEncryptionAlgorithm
+}
+
+func (i encryptedContentInfo) Data() []byte { return i.EncryptedContent }
+
+type safeBag struct {
+	Id         asn1.ObjectIdentifier
+	Value      asn1.RawValue     `asn1:"tag:0,explicit"`
+	Attributes []pkcs12Attribute `asn1:"set,optional"`
+}
+
+type pkcs12Attribute struct {
+	Id    asn1.ObjectIdentifier
+	Value asn1.RawValue `asn1:"set"`
+}
+
+type encryptedPrivateKeyInfo struct {
+	AlgorithmIdentifier pkix.AlgorithmIdentifier
+	EncryptedData       []byte
+}
+
+func (i encryptedPrivateKeyInfo) Algorithm() pkix.AlgorithmIdentifier {
+	return i.AlgorithmIdentifier
+}
+
+func (i encryptedPrivateKeyInfo) Data() []byte {
+	return i.EncryptedData
+}
+
+// PEM block types
+const (
+	certificateType = "CERTIFICATE"
+	privateKeyType  = "PRIVATE KEY"
+)
+
+// unmarshal calls asn1.Unmarshal, but also returns an error if there is any
+// trailing data after unmarshaling.
+func unmarshal(in []byte, out interface{}) error {
+	trailing, err := asn1.Unmarshal(in, out)
+	if err != nil {
+		return err
+	}
+	if len(trailing) != 0 {
+		return errors.New("pkcs12: trailing data found")
+	}
+	return nil
+}
+
+// ToPEM converts all "safe bags" contained in pfxData to PEM blocks.
+// Unknown attributes are discarded.
+//
+// Note that although the returned PEM blocks for private keys have type
+// "PRIVATE KEY", the bytes are not encoded according to PKCS #8, but according
+// to PKCS #1 for RSA keys and SEC 1 for ECDSA keys.
+func ToPEM(pfxData []byte, password string) ([]*pem.Block, error) {
+	encodedPassword, err := bmpString(password)
+	if err != nil {
+		return nil, ErrIncorrectPassword
+	}
+
+	bags, encodedPassword, err := getSafeContents(pfxData, encodedPassword)
+
+	if err != nil {
+		return nil, err
+	}
+
+	blocks := make([]*pem.Block, 0, len(bags))
+	for _, bag := range bags {
+		block, err := convertBag(&bag, encodedPassword)
+		if err != nil {
+			return nil, err
+		}
+		blocks = append(blocks, block)
+	}
+
+	return blocks, nil
+}
+
+func convertBag(bag *safeBag, password []byte) (*pem.Block, error) {
+	block := &pem.Block{
+		Headers: make(map[string]string),
+	}
+
+	for _, attribute := range bag.Attributes {
+		k, v, err := convertAttribute(&attribute)
+		if err == errUnknownAttributeOID {
+			continue
+		}
+		if err != nil {
+			return nil, err
+		}
+		block.Headers[k] = v
+	}
+
+	switch {
+	case bag.Id.Equal(oidCertBag):
+		block.Type = certificateType
+		certsData, err := decodeCertBag(bag.Value.Bytes)
+		if err != nil {
+			return nil, err
+		}
+		block.Bytes = certsData
+	case bag.Id.Equal(oidPKCS8ShroundedKeyBag):
+		block.Type = privateKeyType
+
+		key, err := decodePkcs8ShroudedKeyBag(bag.Value.Bytes, password)
+		if err != nil {
+			return nil, err
+		}
+
+		switch key := key.(type) {
+		case *rsa.PrivateKey:
+			block.Bytes = x509.MarshalPKCS1PrivateKey(key)
+		case *ecdsa.PrivateKey:
+			block.Bytes, err = x509.MarshalECPrivateKey(key)
+			if err != nil {
+				return nil, err
+			}
+		default:
+			return nil, errors.New("found unknown private key type in PKCS#8 wrapping")
+		}
+	default:
+		return nil, errors.New("don't know how to convert a safe bag of type " + bag.Id.String())
+	}
+	return block, nil
+}
+
+func convertAttribute(attribute *pkcs12Attribute) (key, value string, err error) {
+	isString := false
+
+	switch {
+	case attribute.Id.Equal(oidFriendlyName):
+		key = "friendlyName"
+		isString = true
+	case attribute.Id.Equal(oidLocalKeyID):
+		key = "localKeyId"
+	case attribute.Id.Equal(oidMicrosoftCSPName):
+		// This key is chosen to match OpenSSL.
+		key = "Microsoft CSP Name"
+		isString = true
+	default:
+		return "", "", errUnknownAttributeOID
+	}
+
+	if isString {
+		if err := unmarshal(attribute.Value.Bytes, &attribute.Value); err != nil {
+			return "", "", err
+		}
+		if value, err = decodeBMPString(attribute.Value.Bytes); err != nil {
+			return "", "", err
+		}
+	} else {
+		var id []byte
+		if err := unmarshal(attribute.Value.Bytes, &id); err != nil {
+			return "", "", err
+		}
+		value = hex.EncodeToString(id)
+	}
+
+	return key, value, nil
+}
+
+// Decode extracts a certificate and private key from pfxData. This function
+// assumes that there is only one certificate and only one private key in the
+// pfxData; if there are more use ToPEM instead.
+func Decode(pfxData []byte, password string) (privateKey interface{}, certificate *x509.Certificate, err error) {
+	encodedPassword, err := bmpString(password)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	bags, encodedPassword, err := getSafeContents(pfxData, encodedPassword)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	if len(bags) != 2 {
+		err = errors.New("pkcs12: expected exactly two safe bags in the PFX PDU")
+		return
+	}
+
+	for _, bag := range bags {
+		switch {
+		case bag.Id.Equal(oidCertBag):
+			if certificate != nil {
+				err = errors.New("pkcs12: expected exactly one certificate bag")
+			}
+
+			certsData, err := decodeCertBag(bag.Value.Bytes)
+			if err != nil {
+				return nil, nil, err
+			}
+			certs, err := x509.ParseCertificates(certsData)
+			if err != nil {
+				return nil, nil, err
+			}
+			if len(certs) != 1 {
+				err = errors.New("pkcs12: expected exactly one certificate in the certBag")
+				return nil, nil, err
+			}
+			certificate = certs[0]
+
+		case bag.Id.Equal(oidPKCS8ShroundedKeyBag):
+			if privateKey != nil {
+				err = errors.New("pkcs12: expected exactly one key bag")
+				return nil, nil, err
+			}
+
+			if privateKey, err = decodePkcs8ShroudedKeyBag(bag.Value.Bytes, encodedPassword); err != nil {
+				return nil, nil, err
+			}
+		}
+	}
+
+	if certificate == nil {
+		return nil, nil, errors.New("pkcs12: certificate missing")
+	}
+	if privateKey == nil {
+		return nil, nil, errors.New("pkcs12: private key missing")
+	}
+
+	return
+}
+
+func getSafeContents(p12Data, password []byte) (bags []safeBag, updatedPassword []byte, err error) {
+	pfx := new(pfxPdu)
+	if err := unmarshal(p12Data, pfx); err != nil {
+		return nil, nil, errors.New("pkcs12: error reading P12 data: " + err.Error())
+	}
+
+	if pfx.Version != 3 {
+		return nil, nil, NotImplementedError("can only decode v3 PFX PDU's")
+	}
+
+	if !pfx.AuthSafe.ContentType.Equal(oidDataContentType) {
+		return nil, nil, NotImplementedError("only password-protected PFX is implemented")
+	}
+
+	// unmarshal the explicit bytes in the content for type 'data'
+	if err := unmarshal(pfx.AuthSafe.Content.Bytes, &pfx.AuthSafe.Content); err != nil {
+		return nil, nil, err
+	}
+
+	if len(pfx.MacData.Mac.Algorithm.Algorithm) == 0 {
+		return nil, nil, errors.New("pkcs12: no MAC in data")
+	}
+
+	if err := verifyMac(&pfx.MacData, pfx.AuthSafe.Content.Bytes, password); err != nil {
+		if err == ErrIncorrectPassword && len(password) == 2 && password[0] == 0 && password[1] == 0 {
+			// some implementations use an empty byte array
+			// for the empty string password try one more
+			// time with empty-empty password
+			password = nil
+			err = verifyMac(&pfx.MacData, pfx.AuthSafe.Content.Bytes, password)
+		}
+		if err != nil {
+			return nil, nil, err
+		}
+	}
+
+	var authenticatedSafe []contentInfo
+	if err := unmarshal(pfx.AuthSafe.Content.Bytes, &authenticatedSafe); err != nil {
+		return nil, nil, err
+	}
+
+	if len(authenticatedSafe) != 2 {
+		return nil, nil, NotImplementedError("expected exactly two items in the authenticated safe")
+	}
+
+	for _, ci := range authenticatedSafe {
+		var data []byte
+
+		switch {
+		case ci.ContentType.Equal(oidDataContentType):
+			if err := unmarshal(ci.Content.Bytes, &data); err != nil {
+				return nil, nil, err
+			}
+		case ci.ContentType.Equal(oidEncryptedDataContentType):
+			var encryptedData encryptedData
+			if err := unmarshal(ci.Content.Bytes, &encryptedData); err != nil {
+				return nil, nil, err
+			}
+			if encryptedData.Version != 0 {
+				return nil, nil, NotImplementedError("only version 0 of EncryptedData is supported")
+			}
+			if data, err = pbDecrypt(encryptedData.EncryptedContentInfo, password); err != nil {
+				return nil, nil, err
+			}
+		default:
+			return nil, nil, NotImplementedError("only data and encryptedData content types are supported in authenticated safe")
+		}
+
+		var safeContents []safeBag
+		if err := unmarshal(data, &safeContents); err != nil {
+			return nil, nil, err
+		}
+		bags = append(bags, safeContents...)
+	}
+
+	return bags, password, nil
+}
diff --git a/vendor/golang.org/x/crypto/pkcs12/safebags.go b/vendor/golang.org/x/crypto/pkcs12/safebags.go
new file mode 100644
index 0000000000..def1f7b98d
--- /dev/null
+++ b/vendor/golang.org/x/crypto/pkcs12/safebags.go
@@ -0,0 +1,57 @@
+// 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 (
+	"crypto/x509"
+	"encoding/asn1"
+	"errors"
+)
+
+var (
+	// see https://tools.ietf.org/html/rfc7292#appendix-D
+	oidCertTypeX509Certificate = asn1.ObjectIdentifier([]int{1, 2, 840, 113549, 1, 9, 22, 1})
+	oidPKCS8ShroundedKeyBag    = asn1.ObjectIdentifier([]int{1, 2, 840, 113549, 1, 12, 10, 1, 2})
+	oidCertBag                 = asn1.ObjectIdentifier([]int{1, 2, 840, 113549, 1, 12, 10, 1, 3})
+)
+
+type certBag struct {
+	Id   asn1.ObjectIdentifier
+	Data []byte `asn1:"tag:0,explicit"`
+}
+
+func decodePkcs8ShroudedKeyBag(asn1Data, password []byte) (privateKey interface{}, err error) {
+	pkinfo := new(encryptedPrivateKeyInfo)
+	if err = unmarshal(asn1Data, pkinfo); err != nil {
+		return nil, errors.New("pkcs12: error decoding PKCS#8 shrouded key bag: " + err.Error())
+	}
+
+	pkData, err := pbDecrypt(pkinfo, password)
+	if err != nil {
+		return nil, errors.New("pkcs12: error decrypting PKCS#8 shrouded key bag: " + err.Error())
+	}
+
+	ret := new(asn1.RawValue)
+	if err = unmarshal(pkData, ret); err != nil {
+		return nil, errors.New("pkcs12: error unmarshaling decrypted private key: " + err.Error())
+	}
+
+	if privateKey, err = x509.ParsePKCS8PrivateKey(pkData); err != nil {
+		return nil, errors.New("pkcs12: error parsing PKCS#8 private key: " + err.Error())
+	}
+
+	return privateKey, nil
+}
+
+func decodeCertBag(asn1Data []byte) (x509Certificates []byte, err error) {
+	bag := new(certBag)
+	if err := unmarshal(asn1Data, bag); err != nil {
+		return nil, errors.New("pkcs12: error decoding cert bag: " + err.Error())
+	}
+	if !bag.Id.Equal(oidCertTypeX509Certificate) {
+		return nil, NotImplementedError("only X509 certificates are supported")
+	}
+	return bag.Data, nil
+}