remove pod security policy; additional policy/v1beta1 cleanup; use informers for descheduler unit tests

update go to 1.19 and helm kubernetes cluster to 1.25 bump -rc.0 to 1.25 GA bump k8s utils library bump golang-ci use go 1.19 for helm github action upgrade kubectl from 0.20 to 0.25 Signed-off-by: Amir Alavi <amiralavi7@gmail.com>
2026-01-28 14:41:10 +01:00 · 2022-09-01 21:26:19 -04:00
parent c9b0fbe467
commit e8fae9a3b7
171 changed files with 23514 additions and 692 deletions
--- a/vendor/golang.org/x/crypto/pkcs12/bmp-string.go
+++ 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
+}
--- a/vendor/golang.org/x/crypto/pkcs12/crypto.go
+++ 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
+}
--- a/vendor/golang.org/x/crypto/pkcs12/errors.go
+++ 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)
+}
--- a/vendor/golang.org/x/crypto/pkcs12/internal/rc2/rc2.go
+++ 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)
+}
--- a/vendor/golang.org/x/crypto/pkcs12/mac.go
+++ 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
+}
--- a/vendor/golang.org/x/crypto/pkcs12/pbkdf.go
+++ 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".
+}
--- a/vendor/golang.org/x/crypto/pkcs12/pkcs12.go
+++ 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
+}
--- a/vendor/golang.org/x/crypto/pkcs12/safebags.go
+++ 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
+}
--- a/vendor/golang.org/x/oauth2/authhandler/authhandler.go
+++ b/vendor/golang.org/x/oauth2/authhandler/authhandler.go
@@ -0,0 +1,56 @@
+// Copyright 2021 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 authhandler implements a TokenSource to support
+// "three-legged OAuth 2.0" via a custom AuthorizationHandler.
+package authhandler
+
+import (
+	"context"
+	"errors"
+
+	"golang.org/x/oauth2"
+)
+
+// AuthorizationHandler is a 3-legged-OAuth helper that prompts
+// the user for OAuth consent at the specified auth code URL
+// and returns an auth code and state upon approval.
+type AuthorizationHandler func(authCodeURL string) (code string, state string, err error)
+
+// TokenSource returns an oauth2.TokenSource that fetches access tokens
+// using 3-legged-OAuth flow.
+//
+// The provided context.Context is used for oauth2 Exchange operation.
+//
+// The provided oauth2.Config should be a full configuration containing AuthURL,
+// TokenURL, and Scope.
+//
+// An environment-specific AuthorizationHandler is used to obtain user consent.
+//
+// Per the OAuth protocol, a unique "state" string should be specified here.
+// This token source will verify that the "state" is identical in the request
+// and response before exchanging the auth code for OAuth token to prevent CSRF
+// attacks.
+func TokenSource(ctx context.Context, config *oauth2.Config, state string, authHandler AuthorizationHandler) oauth2.TokenSource {
+	return oauth2.ReuseTokenSource(nil, authHandlerSource{config: config, ctx: ctx, authHandler: authHandler, state: state})
+}
+
+type authHandlerSource struct {
+	ctx         context.Context
+	config      *oauth2.Config
+	authHandler AuthorizationHandler
+	state       string
+}
+
+func (source authHandlerSource) Token() (*oauth2.Token, error) {
+	url := source.config.AuthCodeURL(source.state)
+	code, state, err := source.authHandler(url)
+	if err != nil {
+		return nil, err
+	}
+	if state != source.state {
+		return nil, errors.New("state mismatch in 3-legged-OAuth flow")
+	}
+	return source.config.Exchange(source.ctx, code)
+}
--- a/vendor/golang.org/x/oauth2/google/appengine.go
+++ b/vendor/golang.org/x/oauth2/google/appengine.go
@@ -0,0 +1,38 @@
+// Copyright 2014 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 google
+
+import (
+	"context"
+	"time"
+
+	"golang.org/x/oauth2"
+)
+
+// Set at init time by appengine_gen1.go. If nil, we're not on App Engine standard first generation (<= Go 1.9) or App Engine flexible.
+var appengineTokenFunc func(c context.Context, scopes ...string) (token string, expiry time.Time, err error)
+
+// Set at init time by appengine_gen1.go. If nil, we're not on App Engine standard first generation (<= Go 1.9) or App Engine flexible.
+var appengineAppIDFunc func(c context.Context) string
+
+// AppEngineTokenSource returns a token source that fetches tokens from either
+// the current application's service account or from the metadata server,
+// depending on the App Engine environment. See below for environment-specific
+// details. If you are implementing a 3-legged OAuth 2.0 flow on App Engine that
+// involves user accounts, see oauth2.Config instead.
+//
+// First generation App Engine runtimes (<= Go 1.9):
+// AppEngineTokenSource returns a token source that fetches tokens issued to the
+// current App Engine application's service account. The provided context must have
+// come from appengine.NewContext.
+//
+// Second generation App Engine runtimes (>= Go 1.11) and App Engine flexible:
+// AppEngineTokenSource is DEPRECATED on second generation runtimes and on the
+// flexible environment. It delegates to ComputeTokenSource, and the provided
+// context and scopes are not used. Please use DefaultTokenSource (or ComputeTokenSource,
+// which DefaultTokenSource will use in this case) instead.
+func AppEngineTokenSource(ctx context.Context, scope ...string) oauth2.TokenSource {
+	return appEngineTokenSource(ctx, scope...)
+}
--- a/vendor/golang.org/x/oauth2/google/appengine_gen1.go
+++ b/vendor/golang.org/x/oauth2/google/appengine_gen1.go
@@ -0,0 +1,78 @@
+// Copyright 2018 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.
+
+//go:build appengine
+// +build appengine
+
+// This file applies to App Engine first generation runtimes (<= Go 1.9).
+
+package google
+
+import (
+	"context"
+	"sort"
+	"strings"
+	"sync"
+
+	"golang.org/x/oauth2"
+	"google.golang.org/appengine"
+)
+
+func init() {
+	appengineTokenFunc = appengine.AccessToken
+	appengineAppIDFunc = appengine.AppID
+}
+
+// See comment on AppEngineTokenSource in appengine.go.
+func appEngineTokenSource(ctx context.Context, scope ...string) oauth2.TokenSource {
+	scopes := append([]string{}, scope...)
+	sort.Strings(scopes)
+	return &gaeTokenSource{
+		ctx:    ctx,
+		scopes: scopes,
+		key:    strings.Join(scopes, " "),
+	}
+}
+
+// aeTokens helps the fetched tokens to be reused until their expiration.
+var (
+	aeTokensMu sync.Mutex
+	aeTokens   = make(map[string]*tokenLock) // key is space-separated scopes
+)
+
+type tokenLock struct {
+	mu sync.Mutex // guards t; held while fetching or updating t
+	t  *oauth2.Token
+}
+
+type gaeTokenSource struct {
+	ctx    context.Context
+	scopes []string
+	key    string // to aeTokens map; space-separated scopes
+}
+
+func (ts *gaeTokenSource) Token() (*oauth2.Token, error) {
+	aeTokensMu.Lock()
+	tok, ok := aeTokens[ts.key]
+	if !ok {
+		tok = &tokenLock{}
+		aeTokens[ts.key] = tok
+	}
+	aeTokensMu.Unlock()
+
+	tok.mu.Lock()
+	defer tok.mu.Unlock()
+	if tok.t.Valid() {
+		return tok.t, nil
+	}
+	access, exp, err := appengineTokenFunc(ts.ctx, ts.scopes...)
+	if err != nil {
+		return nil, err
+	}
+	tok.t = &oauth2.Token{
+		AccessToken: access,
+		Expiry:      exp,
+	}
+	return tok.t, nil
+}
--- a/vendor/golang.org/x/oauth2/google/appengine_gen2_flex.go
+++ b/vendor/golang.org/x/oauth2/google/appengine_gen2_flex.go
@@ -0,0 +1,28 @@
+// Copyright 2018 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.
+
+//go:build !appengine
+// +build !appengine
+
+// This file applies to App Engine second generation runtimes (>= Go 1.11) and App Engine flexible.
+
+package google
+
+import (
+	"context"
+	"log"
+	"sync"
+
+	"golang.org/x/oauth2"
+)
+
+var logOnce sync.Once // only spam about deprecation once
+
+// See comment on AppEngineTokenSource in appengine.go.
+func appEngineTokenSource(ctx context.Context, scope ...string) oauth2.TokenSource {
+	logOnce.Do(func() {
+		log.Print("google: AppEngineTokenSource is deprecated on App Engine standard second generation runtimes (>= Go 1.11) and App Engine flexible. Please use DefaultTokenSource or ComputeTokenSource.")
+	})
+	return ComputeTokenSource("")
+}
--- a/vendor/golang.org/x/oauth2/google/default.go
+++ b/vendor/golang.org/x/oauth2/google/default.go
@@ -0,0 +1,221 @@
+// 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 google
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"path/filepath"
+	"runtime"
+
+	"cloud.google.com/go/compute/metadata"
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/authhandler"
+)
+
+// Credentials holds Google credentials, including "Application Default Credentials".
+// For more details, see:
+// https://developers.google.com/accounts/docs/application-default-credentials
+// Credentials from external accounts (workload identity federation) are used to
+// identify a particular application from an on-prem or non-Google Cloud platform
+// including Amazon Web Services (AWS), Microsoft Azure or any identity provider
+// that supports OpenID Connect (OIDC).
+type Credentials struct {
+	ProjectID   string // may be empty
+	TokenSource oauth2.TokenSource
+
+	// JSON contains the raw bytes from a JSON credentials file.
+	// This field may be nil if authentication is provided by the
+	// environment and not with a credentials file, e.g. when code is
+	// running on Google Cloud Platform.
+	JSON []byte
+}
+
+// DefaultCredentials is the old name of Credentials.
+//
+// Deprecated: use Credentials instead.
+type DefaultCredentials = Credentials
+
+// CredentialsParams holds user supplied parameters that are used together
+// with a credentials file for building a Credentials object.
+type CredentialsParams struct {
+	// Scopes is the list OAuth scopes. Required.
+	// Example: https://www.googleapis.com/auth/cloud-platform
+	Scopes []string
+
+	// Subject is the user email used for domain wide delegation (see
+	// https://developers.google.com/identity/protocols/oauth2/service-account#delegatingauthority).
+	// Optional.
+	Subject string
+
+	// AuthHandler is the AuthorizationHandler used for 3-legged OAuth flow. Optional.
+	AuthHandler authhandler.AuthorizationHandler
+
+	// State is a unique string used with AuthHandler. Optional.
+	State string
+}
+
+func (params CredentialsParams) deepCopy() CredentialsParams {
+	paramsCopy := params
+	paramsCopy.Scopes = make([]string, len(params.Scopes))
+	copy(paramsCopy.Scopes, params.Scopes)
+	return paramsCopy
+}
+
+// DefaultClient returns an HTTP Client that uses the
+// DefaultTokenSource to obtain authentication credentials.
+func DefaultClient(ctx context.Context, scope ...string) (*http.Client, error) {
+	ts, err := DefaultTokenSource(ctx, scope...)
+	if err != nil {
+		return nil, err
+	}
+	return oauth2.NewClient(ctx, ts), nil
+}
+
+// DefaultTokenSource returns the token source for
+// "Application Default Credentials".
+// It is a shortcut for FindDefaultCredentials(ctx, scope).TokenSource.
+func DefaultTokenSource(ctx context.Context, scope ...string) (oauth2.TokenSource, error) {
+	creds, err := FindDefaultCredentials(ctx, scope...)
+	if err != nil {
+		return nil, err
+	}
+	return creds.TokenSource, nil
+}
+
+// FindDefaultCredentialsWithParams searches for "Application Default Credentials".
+//
+// It looks for credentials in the following places,
+// preferring the first location found:
+//
+//   1. A JSON file whose path is specified by the
+//      GOOGLE_APPLICATION_CREDENTIALS environment variable.
+//      For workload identity federation, refer to
+//      https://cloud.google.com/iam/docs/how-to#using-workload-identity-federation on
+//      how to generate the JSON configuration file for on-prem/non-Google cloud
+//      platforms.
+//   2. A JSON file in a location known to the gcloud command-line tool.
+//      On Windows, this is %APPDATA%/gcloud/application_default_credentials.json.
+//      On other systems, $HOME/.config/gcloud/application_default_credentials.json.
+//   3. On Google App Engine standard first generation runtimes (<= Go 1.9) it uses
+//      the appengine.AccessToken function.
+//   4. On Google Compute Engine, Google App Engine standard second generation runtimes
+//      (>= Go 1.11), and Google App Engine flexible environment, it fetches
+//      credentials from the metadata server.
+func FindDefaultCredentialsWithParams(ctx context.Context, params CredentialsParams) (*Credentials, error) {
+	// Make defensive copy of the slices in params.
+	params = params.deepCopy()
+
+	// First, try the environment variable.
+	const envVar = "GOOGLE_APPLICATION_CREDENTIALS"
+	if filename := os.Getenv(envVar); filename != "" {
+		creds, err := readCredentialsFile(ctx, filename, params)
+		if err != nil {
+			return nil, fmt.Errorf("google: error getting credentials using %v environment variable: %v", envVar, err)
+		}
+		return creds, nil
+	}
+
+	// Second, try a well-known file.
+	filename := wellKnownFile()
+	if creds, err := readCredentialsFile(ctx, filename, params); err == nil {
+		return creds, nil
+	} else if !os.IsNotExist(err) {
+		return nil, fmt.Errorf("google: error getting credentials using well-known file (%v): %v", filename, err)
+	}
+
+	// Third, if we're on a Google App Engine standard first generation runtime (<= Go 1.9)
+	// use those credentials. App Engine standard second generation runtimes (>= Go 1.11)
+	// and App Engine flexible use ComputeTokenSource and the metadata server.
+	if appengineTokenFunc != nil {
+		return &DefaultCredentials{
+			ProjectID:   appengineAppIDFunc(ctx),
+			TokenSource: AppEngineTokenSource(ctx, params.Scopes...),
+		}, nil
+	}
+
+	// Fourth, if we're on Google Compute Engine, an App Engine standard second generation runtime,
+	// or App Engine flexible, use the metadata server.
+	if metadata.OnGCE() {
+		id, _ := metadata.ProjectID()
+		return &DefaultCredentials{
+			ProjectID:   id,
+			TokenSource: ComputeTokenSource("", params.Scopes...),
+		}, nil
+	}
+
+	// None are found; return helpful error.
+	const url = "https://developers.google.com/accounts/docs/application-default-credentials"
+	return nil, fmt.Errorf("google: could not find default credentials. See %v for more information.", url)
+}
+
+// FindDefaultCredentials invokes FindDefaultCredentialsWithParams with the specified scopes.
+func FindDefaultCredentials(ctx context.Context, scopes ...string) (*Credentials, error) {
+	var params CredentialsParams
+	params.Scopes = scopes
+	return FindDefaultCredentialsWithParams(ctx, params)
+}
+
+// CredentialsFromJSONWithParams obtains Google credentials from a JSON value. The JSON can
+// represent either a Google Developers Console client_credentials.json file (as in ConfigFromJSON),
+// a Google Developers service account key file, a gcloud user credentials file (a.k.a. refresh
+// token JSON), or the JSON configuration file for workload identity federation in non-Google cloud
+// platforms (see https://cloud.google.com/iam/docs/how-to#using-workload-identity-federation).
+func CredentialsFromJSONWithParams(ctx context.Context, jsonData []byte, params CredentialsParams) (*Credentials, error) {
+	// Make defensive copy of the slices in params.
+	params = params.deepCopy()
+
+	// First, attempt to parse jsonData as a Google Developers Console client_credentials.json.
+	config, _ := ConfigFromJSON(jsonData, params.Scopes...)
+	if config != nil {
+		return &Credentials{
+			ProjectID:   "",
+			TokenSource: authhandler.TokenSource(ctx, config, params.State, params.AuthHandler),
+			JSON:        jsonData,
+		}, nil
+	}
+
+	// Otherwise, parse jsonData as one of the other supported credentials files.
+	var f credentialsFile
+	if err := json.Unmarshal(jsonData, &f); err != nil {
+		return nil, err
+	}
+	ts, err := f.tokenSource(ctx, params)
+	if err != nil {
+		return nil, err
+	}
+	return &DefaultCredentials{
+		ProjectID:   f.ProjectID,
+		TokenSource: ts,
+		JSON:        jsonData,
+	}, nil
+}
+
+// CredentialsFromJSON invokes CredentialsFromJSONWithParams with the specified scopes.
+func CredentialsFromJSON(ctx context.Context, jsonData []byte, scopes ...string) (*Credentials, error) {
+	var params CredentialsParams
+	params.Scopes = scopes
+	return CredentialsFromJSONWithParams(ctx, jsonData, params)
+}
+
+func wellKnownFile() string {
+	const f = "application_default_credentials.json"
+	if runtime.GOOS == "windows" {
+		return filepath.Join(os.Getenv("APPDATA"), "gcloud", f)
+	}
+	return filepath.Join(guessUnixHomeDir(), ".config", "gcloud", f)
+}
+
+func readCredentialsFile(ctx context.Context, filename string, params CredentialsParams) (*DefaultCredentials, error) {
+	b, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	return CredentialsFromJSONWithParams(ctx, b, params)
+}
--- a/vendor/golang.org/x/oauth2/google/doc.go
+++ b/vendor/golang.org/x/oauth2/google/doc.go
@@ -0,0 +1,79 @@
+// Copyright 2018 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 google provides support for making OAuth2 authorized and authenticated
+// HTTP requests to Google APIs. It supports the Web server flow, client-side
+// credentials, service accounts, Google Compute Engine service accounts,
+// Google App Engine service accounts and workload identity federation
+// from non-Google cloud platforms.
+//
+// A brief overview of the package follows. For more information, please read
+// https://developers.google.com/accounts/docs/OAuth2
+// and
+// https://developers.google.com/accounts/docs/application-default-credentials.
+// For more information on using workload identity federation, refer to
+// https://cloud.google.com/iam/docs/how-to#using-workload-identity-federation.
+//
+// OAuth2 Configs
+//
+// Two functions in this package return golang.org/x/oauth2.Config values from Google credential
+// data. Google supports two JSON formats for OAuth2 credentials: one is handled by ConfigFromJSON,
+// the other by JWTConfigFromJSON. The returned Config can be used to obtain a TokenSource or
+// create an http.Client.
+//
+// Workload Identity Federation
+//
+// Using workload identity federation, your application can access Google Cloud
+// resources from Amazon Web Services (AWS), Microsoft Azure or any identity
+// provider that supports OpenID Connect (OIDC).
+// Traditionally, applications running outside Google Cloud have used service
+// account keys to access Google Cloud resources. Using identity federation,
+// you can allow your workload to impersonate a service account.
+// This lets you access Google Cloud resources directly, eliminating the
+// maintenance and security burden associated with service account keys.
+//
+// Follow the detailed instructions on how to configure Workload Identity Federation
+// in various platforms:
+//
+//   Amazon Web Services (AWS): https://cloud.google.com/iam/docs/access-resources-aws
+//   Microsoft Azure: https://cloud.google.com/iam/docs/access-resources-azure
+//   OIDC identity provider: https://cloud.google.com/iam/docs/access-resources-oidc
+//
+// For OIDC providers, the library can retrieve OIDC tokens either from a
+// local file location (file-sourced credentials) or from a local server
+// (URL-sourced credentials).
+// For file-sourced credentials, a background process needs to be continuously
+// refreshing the file location with a new OIDC token prior to expiration.
+// For tokens with one hour lifetimes, the token needs to be updated in the file
+// every hour. The token can be stored directly as plain text or in JSON format.
+// For URL-sourced credentials, a local server needs to host a GET endpoint to
+// return the OIDC token. The response can be in plain text or JSON.
+// Additional required request headers can also be specified.
+//
+//
+// Credentials
+//
+// The Credentials type represents Google credentials, including Application Default
+// Credentials.
+//
+// Use FindDefaultCredentials to obtain Application Default Credentials.
+// FindDefaultCredentials looks in some well-known places for a credentials file, and
+// will call AppEngineTokenSource or ComputeTokenSource as needed.
+//
+// Application Default Credentials also support workload identity federation to
+// access Google Cloud resources from non-Google Cloud platforms including Amazon
+// Web Services (AWS), Microsoft Azure or any identity provider that supports
+// OpenID Connect (OIDC). Workload identity federation is recommended for
+// non-Google Cloud environments as it avoids the need to download, manage and
+// store service account private keys locally.
+//
+// DefaultClient and DefaultTokenSource are convenience methods. They first call FindDefaultCredentials,
+// then use the credentials to construct an http.Client or an oauth2.TokenSource.
+//
+// Use CredentialsFromJSON to obtain credentials from either of the two JSON formats
+// described in OAuth2 Configs, above. The TokenSource in the returned value is the
+// same as the one obtained from the oauth2.Config returned from ConfigFromJSON or
+// JWTConfigFromJSON, but the Credentials may contain additional information
+// that is useful is some circumstances.
+package google // import "golang.org/x/oauth2/google"
--- a/vendor/golang.org/x/oauth2/google/google.go
+++ b/vendor/golang.org/x/oauth2/google/google.go
@@ -0,0 +1,270 @@
+// Copyright 2014 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 google
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/url"
+	"strings"
+	"time"
+
+	"cloud.google.com/go/compute/metadata"
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/google/internal/externalaccount"
+	"golang.org/x/oauth2/jwt"
+)
+
+// Endpoint is Google's OAuth 2.0 default endpoint.
+var Endpoint = oauth2.Endpoint{
+	AuthURL:   "https://accounts.google.com/o/oauth2/auth",
+	TokenURL:  "https://oauth2.googleapis.com/token",
+	AuthStyle: oauth2.AuthStyleInParams,
+}
+
+// JWTTokenURL is Google's OAuth 2.0 token URL to use with the JWT flow.
+const JWTTokenURL = "https://oauth2.googleapis.com/token"
+
+// ConfigFromJSON uses a Google Developers Console client_credentials.json
+// file to construct a config.
+// client_credentials.json can be downloaded from
+// https://console.developers.google.com, under "Credentials". Download the Web
+// application credentials in the JSON format and provide the contents of the
+// file as jsonKey.
+func ConfigFromJSON(jsonKey []byte, scope ...string) (*oauth2.Config, error) {
+	type cred struct {
+		ClientID     string   `json:"client_id"`
+		ClientSecret string   `json:"client_secret"`
+		RedirectURIs []string `json:"redirect_uris"`
+		AuthURI      string   `json:"auth_uri"`
+		TokenURI     string   `json:"token_uri"`
+	}
+	var j struct {
+		Web       *cred `json:"web"`
+		Installed *cred `json:"installed"`
+	}
+	if err := json.Unmarshal(jsonKey, &j); err != nil {
+		return nil, err
+	}
+	var c *cred
+	switch {
+	case j.Web != nil:
+		c = j.Web
+	case j.Installed != nil:
+		c = j.Installed
+	default:
+		return nil, fmt.Errorf("oauth2/google: no credentials found")
+	}
+	if len(c.RedirectURIs) < 1 {
+		return nil, errors.New("oauth2/google: missing redirect URL in the client_credentials.json")
+	}
+	return &oauth2.Config{
+		ClientID:     c.ClientID,
+		ClientSecret: c.ClientSecret,
+		RedirectURL:  c.RedirectURIs[0],
+		Scopes:       scope,
+		Endpoint: oauth2.Endpoint{
+			AuthURL:  c.AuthURI,
+			TokenURL: c.TokenURI,
+		},
+	}, nil
+}
+
+// JWTConfigFromJSON uses a Google Developers service account JSON key file to read
+// the credentials that authorize and authenticate the requests.
+// Create a service account on "Credentials" for your project at
+// https://console.developers.google.com to download a JSON key file.
+func JWTConfigFromJSON(jsonKey []byte, scope ...string) (*jwt.Config, error) {
+	var f credentialsFile
+	if err := json.Unmarshal(jsonKey, &f); err != nil {
+		return nil, err
+	}
+	if f.Type != serviceAccountKey {
+		return nil, fmt.Errorf("google: read JWT from JSON credentials: 'type' field is %q (expected %q)", f.Type, serviceAccountKey)
+	}
+	scope = append([]string(nil), scope...) // copy
+	return f.jwtConfig(scope, ""), nil
+}
+
+// JSON key file types.
+const (
+	serviceAccountKey          = "service_account"
+	userCredentialsKey         = "authorized_user"
+	externalAccountKey         = "external_account"
+	impersonatedServiceAccount = "impersonated_service_account"
+)
+
+// credentialsFile is the unmarshalled representation of a credentials file.
+type credentialsFile struct {
+	Type string `json:"type"`
+
+	// Service Account fields
+	ClientEmail  string `json:"client_email"`
+	PrivateKeyID string `json:"private_key_id"`
+	PrivateKey   string `json:"private_key"`
+	AuthURL      string `json:"auth_uri"`
+	TokenURL     string `json:"token_uri"`
+	ProjectID    string `json:"project_id"`
+
+	// User Credential fields
+	// (These typically come from gcloud auth.)
+	ClientSecret string `json:"client_secret"`
+	ClientID     string `json:"client_id"`
+	RefreshToken string `json:"refresh_token"`
+
+	// External Account fields
+	Audience                       string                           `json:"audience"`
+	SubjectTokenType               string                           `json:"subject_token_type"`
+	TokenURLExternal               string                           `json:"token_url"`
+	TokenInfoURL                   string                           `json:"token_info_url"`
+	ServiceAccountImpersonationURL string                           `json:"service_account_impersonation_url"`
+	Delegates                      []string                         `json:"delegates"`
+	CredentialSource               externalaccount.CredentialSource `json:"credential_source"`
+	QuotaProjectID                 string                           `json:"quota_project_id"`
+	WorkforcePoolUserProject       string                           `json:"workforce_pool_user_project"`
+
+	// Service account impersonation
+	SourceCredentials *credentialsFile `json:"source_credentials"`
+}
+
+func (f *credentialsFile) jwtConfig(scopes []string, subject string) *jwt.Config {
+	cfg := &jwt.Config{
+		Email:        f.ClientEmail,
+		PrivateKey:   []byte(f.PrivateKey),
+		PrivateKeyID: f.PrivateKeyID,
+		Scopes:       scopes,
+		TokenURL:     f.TokenURL,
+		Subject:      subject, // This is the user email to impersonate
+	}
+	if cfg.TokenURL == "" {
+		cfg.TokenURL = JWTTokenURL
+	}
+	return cfg
+}
+
+func (f *credentialsFile) tokenSource(ctx context.Context, params CredentialsParams) (oauth2.TokenSource, error) {
+	switch f.Type {
+	case serviceAccountKey:
+		cfg := f.jwtConfig(params.Scopes, params.Subject)
+		return cfg.TokenSource(ctx), nil
+	case userCredentialsKey:
+		cfg := &oauth2.Config{
+			ClientID:     f.ClientID,
+			ClientSecret: f.ClientSecret,
+			Scopes:       params.Scopes,
+			Endpoint: oauth2.Endpoint{
+				AuthURL:   f.AuthURL,
+				TokenURL:  f.TokenURL,
+				AuthStyle: oauth2.AuthStyleInParams,
+			},
+		}
+		if cfg.Endpoint.AuthURL == "" {
+			cfg.Endpoint.AuthURL = Endpoint.AuthURL
+		}
+		if cfg.Endpoint.TokenURL == "" {
+			cfg.Endpoint.TokenURL = Endpoint.TokenURL
+		}
+		tok := &oauth2.Token{RefreshToken: f.RefreshToken}
+		return cfg.TokenSource(ctx, tok), nil
+	case externalAccountKey:
+		cfg := &externalaccount.Config{
+			Audience:                       f.Audience,
+			SubjectTokenType:               f.SubjectTokenType,
+			TokenURL:                       f.TokenURLExternal,
+			TokenInfoURL:                   f.TokenInfoURL,
+			ServiceAccountImpersonationURL: f.ServiceAccountImpersonationURL,
+			ClientSecret:                   f.ClientSecret,
+			ClientID:                       f.ClientID,
+			CredentialSource:               f.CredentialSource,
+			QuotaProjectID:                 f.QuotaProjectID,
+			Scopes:                         params.Scopes,
+			WorkforcePoolUserProject:       f.WorkforcePoolUserProject,
+		}
+		return cfg.TokenSource(ctx)
+	case impersonatedServiceAccount:
+		if f.ServiceAccountImpersonationURL == "" || f.SourceCredentials == nil {
+			return nil, errors.New("missing 'source_credentials' field or 'service_account_impersonation_url' in credentials")
+		}
+
+		ts, err := f.SourceCredentials.tokenSource(ctx, params)
+		if err != nil {
+			return nil, err
+		}
+		imp := externalaccount.ImpersonateTokenSource{
+			Ctx:       ctx,
+			URL:       f.ServiceAccountImpersonationURL,
+			Scopes:    params.Scopes,
+			Ts:        ts,
+			Delegates: f.Delegates,
+		}
+		return oauth2.ReuseTokenSource(nil, imp), nil
+	case "":
+		return nil, errors.New("missing 'type' field in credentials")
+	default:
+		return nil, fmt.Errorf("unknown credential type: %q", f.Type)
+	}
+}
+
+// ComputeTokenSource returns a token source that fetches access tokens
+// from Google Compute Engine (GCE)'s metadata server. It's only valid to use
+// this token source if your program is running on a GCE instance.
+// If no account is specified, "default" is used.
+// If no scopes are specified, a set of default scopes are automatically granted.
+// Further information about retrieving access tokens from the GCE metadata
+// server can be found at https://cloud.google.com/compute/docs/authentication.
+func ComputeTokenSource(account string, scope ...string) oauth2.TokenSource {
+	return oauth2.ReuseTokenSource(nil, computeSource{account: account, scopes: scope})
+}
+
+type computeSource struct {
+	account string
+	scopes  []string
+}
+
+func (cs computeSource) Token() (*oauth2.Token, error) {
+	if !metadata.OnGCE() {
+		return nil, errors.New("oauth2/google: can't get a token from the metadata service; not running on GCE")
+	}
+	acct := cs.account
+	if acct == "" {
+		acct = "default"
+	}
+	tokenURI := "instance/service-accounts/" + acct + "/token"
+	if len(cs.scopes) > 0 {
+		v := url.Values{}
+		v.Set("scopes", strings.Join(cs.scopes, ","))
+		tokenURI = tokenURI + "?" + v.Encode()
+	}
+	tokenJSON, err := metadata.Get(tokenURI)
+	if err != nil {
+		return nil, err
+	}
+	var res struct {
+		AccessToken  string `json:"access_token"`
+		ExpiresInSec int    `json:"expires_in"`
+		TokenType    string `json:"token_type"`
+	}
+	err = json.NewDecoder(strings.NewReader(tokenJSON)).Decode(&res)
+	if err != nil {
+		return nil, fmt.Errorf("oauth2/google: invalid token JSON from metadata: %v", err)
+	}
+	if res.ExpiresInSec == 0 || res.AccessToken == "" {
+		return nil, fmt.Errorf("oauth2/google: incomplete token received from metadata")
+	}
+	tok := &oauth2.Token{
+		AccessToken: res.AccessToken,
+		TokenType:   res.TokenType,
+		Expiry:      time.Now().Add(time.Duration(res.ExpiresInSec) * time.Second),
+	}
+	// NOTE(cbro): add hidden metadata about where the token is from.
+	// This is needed for detection by client libraries to know that credentials come from the metadata server.
+	// This may be removed in a future version of this library.
+	return tok.WithExtra(map[string]interface{}{
+		"oauth2.google.tokenSource":    "compute-metadata",
+		"oauth2.google.serviceAccount": acct,
+	}), nil
+}
--- a/vendor/golang.org/x/oauth2/google/internal/externalaccount/aws.go
+++ b/vendor/golang.org/x/oauth2/google/internal/externalaccount/aws.go
@@ -0,0 +1,470 @@
+// Copyright 2021 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 externalaccount
+
+import (
+	"bytes"
+	"context"
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"os"
+	"path"
+	"sort"
+	"strings"
+	"time"
+
+	"golang.org/x/oauth2"
+)
+
+type awsSecurityCredentials struct {
+	AccessKeyID     string `json:"AccessKeyID"`
+	SecretAccessKey string `json:"SecretAccessKey"`
+	SecurityToken   string `json:"Token"`
+}
+
+// awsRequestSigner is a utility class to sign http requests using a AWS V4 signature.
+type awsRequestSigner struct {
+	RegionName             string
+	AwsSecurityCredentials awsSecurityCredentials
+}
+
+// getenv aliases os.Getenv for testing
+var getenv = os.Getenv
+
+const (
+	// AWS Signature Version 4 signing algorithm identifier.
+	awsAlgorithm = "AWS4-HMAC-SHA256"
+
+	// The termination string for the AWS credential scope value as defined in
+	// https://docs.aws.amazon.com/general/latest/gr/sigv4-create-string-to-sign.html
+	awsRequestType = "aws4_request"
+
+	// The AWS authorization header name for the security session token if available.
+	awsSecurityTokenHeader = "x-amz-security-token"
+
+	// The AWS authorization header name for the auto-generated date.
+	awsDateHeader = "x-amz-date"
+
+	awsTimeFormatLong  = "20060102T150405Z"
+	awsTimeFormatShort = "20060102"
+)
+
+func getSha256(input []byte) (string, error) {
+	hash := sha256.New()
+	if _, err := hash.Write(input); err != nil {
+		return "", err
+	}
+	return hex.EncodeToString(hash.Sum(nil)), nil
+}
+
+func getHmacSha256(key, input []byte) ([]byte, error) {
+	hash := hmac.New(sha256.New, key)
+	if _, err := hash.Write(input); err != nil {
+		return nil, err
+	}
+	return hash.Sum(nil), nil
+}
+
+func cloneRequest(r *http.Request) *http.Request {
+	r2 := new(http.Request)
+	*r2 = *r
+	if r.Header != nil {
+		r2.Header = make(http.Header, len(r.Header))
+
+		// Find total number of values.
+		headerCount := 0
+		for _, headerValues := range r.Header {
+			headerCount += len(headerValues)
+		}
+		copiedHeaders := make([]string, headerCount) // shared backing array for headers' values
+
+		for headerKey, headerValues := range r.Header {
+			headerCount = copy(copiedHeaders, headerValues)
+			r2.Header[headerKey] = copiedHeaders[:headerCount:headerCount]
+			copiedHeaders = copiedHeaders[headerCount:]
+		}
+	}
+	return r2
+}
+
+func canonicalPath(req *http.Request) string {
+	result := req.URL.EscapedPath()
+	if result == "" {
+		return "/"
+	}
+	return path.Clean(result)
+}
+
+func canonicalQuery(req *http.Request) string {
+	queryValues := req.URL.Query()
+	for queryKey := range queryValues {
+		sort.Strings(queryValues[queryKey])
+	}
+	return queryValues.Encode()
+}
+
+func canonicalHeaders(req *http.Request) (string, string) {
+	// Header keys need to be sorted alphabetically.
+	var headers []string
+	lowerCaseHeaders := make(http.Header)
+	for k, v := range req.Header {
+		k := strings.ToLower(k)
+		if _, ok := lowerCaseHeaders[k]; ok {
+			// include additional values
+			lowerCaseHeaders[k] = append(lowerCaseHeaders[k], v...)
+		} else {
+			headers = append(headers, k)
+			lowerCaseHeaders[k] = v
+		}
+	}
+	sort.Strings(headers)
+
+	var fullHeaders bytes.Buffer
+	for _, header := range headers {
+		headerValue := strings.Join(lowerCaseHeaders[header], ",")
+		fullHeaders.WriteString(header)
+		fullHeaders.WriteRune(':')
+		fullHeaders.WriteString(headerValue)
+		fullHeaders.WriteRune('\n')
+	}
+
+	return strings.Join(headers, ";"), fullHeaders.String()
+}
+
+func requestDataHash(req *http.Request) (string, error) {
+	var requestData []byte
+	if req.Body != nil {
+		requestBody, err := req.GetBody()
+		if err != nil {
+			return "", err
+		}
+		defer requestBody.Close()
+
+		requestData, err = ioutil.ReadAll(io.LimitReader(requestBody, 1<<20))
+		if err != nil {
+			return "", err
+		}
+	}
+
+	return getSha256(requestData)
+}
+
+func requestHost(req *http.Request) string {
+	if req.Host != "" {
+		return req.Host
+	}
+	return req.URL.Host
+}
+
+func canonicalRequest(req *http.Request, canonicalHeaderColumns, canonicalHeaderData string) (string, error) {
+	dataHash, err := requestDataHash(req)
+	if err != nil {
+		return "", err
+	}
+
+	return fmt.Sprintf("%s\n%s\n%s\n%s\n%s\n%s", req.Method, canonicalPath(req), canonicalQuery(req), canonicalHeaderData, canonicalHeaderColumns, dataHash), nil
+}
+
+// SignRequest adds the appropriate headers to an http.Request
+// or returns an error if something prevented this.
+func (rs *awsRequestSigner) SignRequest(req *http.Request) error {
+	signedRequest := cloneRequest(req)
+	timestamp := now()
+
+	signedRequest.Header.Add("host", requestHost(req))
+
+	if rs.AwsSecurityCredentials.SecurityToken != "" {
+		signedRequest.Header.Add(awsSecurityTokenHeader, rs.AwsSecurityCredentials.SecurityToken)
+	}
+
+	if signedRequest.Header.Get("date") == "" {
+		signedRequest.Header.Add(awsDateHeader, timestamp.Format(awsTimeFormatLong))
+	}
+
+	authorizationCode, err := rs.generateAuthentication(signedRequest, timestamp)
+	if err != nil {
+		return err
+	}
+	signedRequest.Header.Set("Authorization", authorizationCode)
+
+	req.Header = signedRequest.Header
+	return nil
+}
+
+func (rs *awsRequestSigner) generateAuthentication(req *http.Request, timestamp time.Time) (string, error) {
+	canonicalHeaderColumns, canonicalHeaderData := canonicalHeaders(req)
+
+	dateStamp := timestamp.Format(awsTimeFormatShort)
+	serviceName := ""
+	if splitHost := strings.Split(requestHost(req), "."); len(splitHost) > 0 {
+		serviceName = splitHost[0]
+	}
+
+	credentialScope := fmt.Sprintf("%s/%s/%s/%s", dateStamp, rs.RegionName, serviceName, awsRequestType)
+
+	requestString, err := canonicalRequest(req, canonicalHeaderColumns, canonicalHeaderData)
+	if err != nil {
+		return "", err
+	}
+	requestHash, err := getSha256([]byte(requestString))
+	if err != nil {
+		return "", err
+	}
+
+	stringToSign := fmt.Sprintf("%s\n%s\n%s\n%s", awsAlgorithm, timestamp.Format(awsTimeFormatLong), credentialScope, requestHash)
+
+	signingKey := []byte("AWS4" + rs.AwsSecurityCredentials.SecretAccessKey)
+	for _, signingInput := range []string{
+		dateStamp, rs.RegionName, serviceName, awsRequestType, stringToSign,
+	} {
+		signingKey, err = getHmacSha256(signingKey, []byte(signingInput))
+		if err != nil {
+			return "", err
+		}
+	}
+
+	return fmt.Sprintf("%s Credential=%s/%s, SignedHeaders=%s, Signature=%s", awsAlgorithm, rs.AwsSecurityCredentials.AccessKeyID, credentialScope, canonicalHeaderColumns, hex.EncodeToString(signingKey)), nil
+}
+
+type awsCredentialSource struct {
+	EnvironmentID               string
+	RegionURL                   string
+	RegionalCredVerificationURL string
+	CredVerificationURL         string
+	TargetResource              string
+	requestSigner               *awsRequestSigner
+	region                      string
+	ctx                         context.Context
+	client                      *http.Client
+}
+
+type awsRequestHeader struct {
+	Key   string `json:"key"`
+	Value string `json:"value"`
+}
+
+type awsRequest struct {
+	URL     string             `json:"url"`
+	Method  string             `json:"method"`
+	Headers []awsRequestHeader `json:"headers"`
+}
+
+func (cs awsCredentialSource) doRequest(req *http.Request) (*http.Response, error) {
+	if cs.client == nil {
+		cs.client = oauth2.NewClient(cs.ctx, nil)
+	}
+	return cs.client.Do(req.WithContext(cs.ctx))
+}
+
+func (cs awsCredentialSource) subjectToken() (string, error) {
+	if cs.requestSigner == nil {
+		awsSecurityCredentials, err := cs.getSecurityCredentials()
+		if err != nil {
+			return "", err
+		}
+
+		if cs.region, err = cs.getRegion(); err != nil {
+			return "", err
+		}
+
+		cs.requestSigner = &awsRequestSigner{
+			RegionName:             cs.region,
+			AwsSecurityCredentials: awsSecurityCredentials,
+		}
+	}
+
+	// Generate the signed request to AWS STS GetCallerIdentity API.
+	// Use the required regional endpoint. Otherwise, the request will fail.
+	req, err := http.NewRequest("POST", strings.Replace(cs.RegionalCredVerificationURL, "{region}", cs.region, 1), nil)
+	if err != nil {
+		return "", err
+	}
+	// The full, canonical resource name of the workload identity pool
+	// provider, with or without the HTTPS prefix.
+	// Including this header as part of the signature is recommended to
+	// ensure data integrity.
+	if cs.TargetResource != "" {
+		req.Header.Add("x-goog-cloud-target-resource", cs.TargetResource)
+	}
+	cs.requestSigner.SignRequest(req)
+
+	/*
+	   The GCP STS endpoint expects the headers to be formatted as:
+	   # [
+	   #   {key: 'x-amz-date', value: '...'},
+	   #   {key: 'Authorization', value: '...'},
+	   #   ...
+	   # ]
+	   # And then serialized as:
+	   # quote(json.dumps({
+	   #   url: '...',
+	   #   method: 'POST',
+	   #   headers: [{key: 'x-amz-date', value: '...'}, ...]
+	   # }))
+	*/
+
+	awsSignedReq := awsRequest{
+		URL:    req.URL.String(),
+		Method: "POST",
+	}
+	for headerKey, headerList := range req.Header {
+		for _, headerValue := range headerList {
+			awsSignedReq.Headers = append(awsSignedReq.Headers, awsRequestHeader{
+				Key:   headerKey,
+				Value: headerValue,
+			})
+		}
+	}
+	sort.Slice(awsSignedReq.Headers, func(i, j int) bool {
+		headerCompare := strings.Compare(awsSignedReq.Headers[i].Key, awsSignedReq.Headers[j].Key)
+		if headerCompare == 0 {
+			return strings.Compare(awsSignedReq.Headers[i].Value, awsSignedReq.Headers[j].Value) < 0
+		}
+		return headerCompare < 0
+	})
+
+	result, err := json.Marshal(awsSignedReq)
+	if err != nil {
+		return "", err
+	}
+	return url.QueryEscape(string(result)), nil
+}
+
+func (cs *awsCredentialSource) getRegion() (string, error) {
+	if envAwsRegion := getenv("AWS_REGION"); envAwsRegion != "" {
+		return envAwsRegion, nil
+	}
+	if envAwsRegion := getenv("AWS_DEFAULT_REGION"); envAwsRegion != "" {
+		return envAwsRegion, nil
+	}
+
+	if cs.RegionURL == "" {
+		return "", errors.New("oauth2/google: unable to determine AWS region")
+	}
+
+	req, err := http.NewRequest("GET", cs.RegionURL, nil)
+	if err != nil {
+		return "", err
+	}
+
+	resp, err := cs.doRequest(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	respBody, err := ioutil.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	if err != nil {
+		return "", err
+	}
+
+	if resp.StatusCode != 200 {
+		return "", fmt.Errorf("oauth2/google: unable to retrieve AWS region - %s", string(respBody))
+	}
+
+	// This endpoint will return the region in format: us-east-2b.
+	// Only the us-east-2 part should be used.
+	respBodyEnd := 0
+	if len(respBody) > 1 {
+		respBodyEnd = len(respBody) - 1
+	}
+	return string(respBody[:respBodyEnd]), nil
+}
+
+func (cs *awsCredentialSource) getSecurityCredentials() (result awsSecurityCredentials, err error) {
+	if accessKeyID := getenv("AWS_ACCESS_KEY_ID"); accessKeyID != "" {
+		if secretAccessKey := getenv("AWS_SECRET_ACCESS_KEY"); secretAccessKey != "" {
+			return awsSecurityCredentials{
+				AccessKeyID:     accessKeyID,
+				SecretAccessKey: secretAccessKey,
+				SecurityToken:   getenv("AWS_SESSION_TOKEN"),
+			}, nil
+		}
+	}
+
+	roleName, err := cs.getMetadataRoleName()
+	if err != nil {
+		return
+	}
+
+	credentials, err := cs.getMetadataSecurityCredentials(roleName)
+	if err != nil {
+		return
+	}
+
+	if credentials.AccessKeyID == "" {
+		return result, errors.New("oauth2/google: missing AccessKeyId credential")
+	}
+
+	if credentials.SecretAccessKey == "" {
+		return result, errors.New("oauth2/google: missing SecretAccessKey credential")
+	}
+
+	return credentials, nil
+}
+
+func (cs *awsCredentialSource) getMetadataSecurityCredentials(roleName string) (awsSecurityCredentials, error) {
+	var result awsSecurityCredentials
+
+	req, err := http.NewRequest("GET", fmt.Sprintf("%s/%s", cs.CredVerificationURL, roleName), nil)
+	if err != nil {
+		return result, err
+	}
+	req.Header.Add("Content-Type", "application/json")
+
+	resp, err := cs.doRequest(req)
+	if err != nil {
+		return result, err
+	}
+	defer resp.Body.Close()
+
+	respBody, err := ioutil.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	if err != nil {
+		return result, err
+	}
+
+	if resp.StatusCode != 200 {
+		return result, fmt.Errorf("oauth2/google: unable to retrieve AWS security credentials - %s", string(respBody))
+	}
+
+	err = json.Unmarshal(respBody, &result)
+	return result, err
+}
+
+func (cs *awsCredentialSource) getMetadataRoleName() (string, error) {
+	if cs.CredVerificationURL == "" {
+		return "", errors.New("oauth2/google: unable to determine the AWS metadata server security credentials endpoint")
+	}
+
+	req, err := http.NewRequest("GET", cs.CredVerificationURL, nil)
+	if err != nil {
+		return "", err
+	}
+
+	resp, err := cs.doRequest(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	respBody, err := ioutil.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	if err != nil {
+		return "", err
+	}
+
+	if resp.StatusCode != 200 {
+		return "", fmt.Errorf("oauth2/google: unable to retrieve AWS role name - %s", string(respBody))
+	}
+
+	return string(respBody), nil
+}
--- a/vendor/golang.org/x/oauth2/google/internal/externalaccount/basecredentials.go
+++ b/vendor/golang.org/x/oauth2/google/internal/externalaccount/basecredentials.go
@@ -0,0 +1,270 @@
+// Copyright 2020 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 externalaccount
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/url"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	"golang.org/x/oauth2"
+)
+
+// now aliases time.Now for testing
+var now = func() time.Time {
+	return time.Now().UTC()
+}
+
+// Config stores the configuration for fetching tokens with external credentials.
+type Config struct {
+	// Audience is the Secure Token Service (STS) audience which contains the resource name for the workload
+	// identity pool or the workforce pool and the provider identifier in that pool.
+	Audience string
+	// SubjectTokenType is the STS token type based on the Oauth2.0 token exchange spec
+	// e.g. `urn:ietf:params:oauth:token-type:jwt`.
+	SubjectTokenType string
+	// TokenURL is the STS token exchange endpoint.
+	TokenURL string
+	// TokenInfoURL is the token_info endpoint used to retrieve the account related information (
+	// user attributes like account identifier, eg. email, username, uid, etc). This is
+	// needed for gCloud session account identification.
+	TokenInfoURL string
+	// ServiceAccountImpersonationURL is the URL for the service account impersonation request. This is only
+	// required for workload identity pools when APIs to be accessed have not integrated with UberMint.
+	ServiceAccountImpersonationURL string
+	// ClientSecret is currently only required if token_info endpoint also
+	// needs to be called with the generated GCP access token. When provided, STS will be
+	// called with additional basic authentication using client_id as username and client_secret as password.
+	ClientSecret string
+	// ClientID is only required in conjunction with ClientSecret, as described above.
+	ClientID string
+	// CredentialSource contains the necessary information to retrieve the token itself, as well
+	// as some environmental information.
+	CredentialSource CredentialSource
+	// QuotaProjectID is injected by gCloud. If the value is non-empty, the Auth libraries
+	// will set the x-goog-user-project which overrides the project associated with the credentials.
+	QuotaProjectID string
+	// Scopes contains the desired scopes for the returned access token.
+	Scopes []string
+	// The optional workforce pool user project number when the credential
+	// corresponds to a workforce pool and not a workload identity pool.
+	// The underlying principal must still have serviceusage.services.use IAM
+	// permission to use the project for billing/quota.
+	WorkforcePoolUserProject string
+}
+
+// Each element consists of a list of patterns.  validateURLs checks for matches
+// that include all elements in a given list, in that order.
+
+var (
+	validTokenURLPatterns = []*regexp.Regexp{
+		// The complicated part in the middle matches any number of characters that
+		// aren't period, spaces, or slashes.
+		regexp.MustCompile(`(?i)^[^\.\s\/\\]+\.sts\.googleapis\.com$`),
+		regexp.MustCompile(`(?i)^sts\.googleapis\.com$`),
+		regexp.MustCompile(`(?i)^sts\.[^\.\s\/\\]+\.googleapis\.com$`),
+		regexp.MustCompile(`(?i)^[^\.\s\/\\]+-sts\.googleapis\.com$`),
+	}
+	validImpersonateURLPatterns = []*regexp.Regexp{
+		regexp.MustCompile(`^[^\.\s\/\\]+\.iamcredentials\.googleapis\.com$`),
+		regexp.MustCompile(`^iamcredentials\.googleapis\.com$`),
+		regexp.MustCompile(`^iamcredentials\.[^\.\s\/\\]+\.googleapis\.com$`),
+		regexp.MustCompile(`^[^\.\s\/\\]+-iamcredentials\.googleapis\.com$`),
+	}
+	validWorkforceAudiencePattern *regexp.Regexp = regexp.MustCompile(`//iam\.googleapis\.com/locations/[^/]+/workforcePools/`)
+)
+
+func validateURL(input string, patterns []*regexp.Regexp, scheme string) bool {
+	parsed, err := url.Parse(input)
+	if err != nil {
+		return false
+	}
+	if !strings.EqualFold(parsed.Scheme, scheme) {
+		return false
+	}
+	toTest := parsed.Host
+
+	for _, pattern := range patterns {
+		if pattern.MatchString(toTest) {
+			return true
+		}
+	}
+	return false
+}
+
+func validateWorkforceAudience(input string) bool {
+	return validWorkforceAudiencePattern.MatchString(input)
+}
+
+// TokenSource Returns an external account TokenSource struct. This is to be called by package google to construct a google.Credentials.
+func (c *Config) TokenSource(ctx context.Context) (oauth2.TokenSource, error) {
+	return c.tokenSource(ctx, validTokenURLPatterns, validImpersonateURLPatterns, "https")
+}
+
+// tokenSource is a private function that's directly called by some of the tests,
+// because the unit test URLs are mocked, and would otherwise fail the
+// validity check.
+func (c *Config) tokenSource(ctx context.Context, tokenURLValidPats []*regexp.Regexp, impersonateURLValidPats []*regexp.Regexp, scheme string) (oauth2.TokenSource, error) {
+	valid := validateURL(c.TokenURL, tokenURLValidPats, scheme)
+	if !valid {
+		return nil, fmt.Errorf("oauth2/google: invalid TokenURL provided while constructing tokenSource")
+	}
+
+	if c.ServiceAccountImpersonationURL != "" {
+		valid := validateURL(c.ServiceAccountImpersonationURL, impersonateURLValidPats, scheme)
+		if !valid {
+			return nil, fmt.Errorf("oauth2/google: invalid ServiceAccountImpersonationURL provided while constructing tokenSource")
+		}
+	}
+
+	if c.WorkforcePoolUserProject != "" {
+		valid := validateWorkforceAudience(c.Audience)
+		if !valid {
+			return nil, fmt.Errorf("oauth2/google: workforce_pool_user_project should not be set for non-workforce pool credentials")
+		}
+	}
+
+	ts := tokenSource{
+		ctx:  ctx,
+		conf: c,
+	}
+	if c.ServiceAccountImpersonationURL == "" {
+		return oauth2.ReuseTokenSource(nil, ts), nil
+	}
+	scopes := c.Scopes
+	ts.conf.Scopes = []string{"https://www.googleapis.com/auth/cloud-platform"}
+	imp := ImpersonateTokenSource{
+		Ctx:    ctx,
+		URL:    c.ServiceAccountImpersonationURL,
+		Scopes: scopes,
+		Ts:     oauth2.ReuseTokenSource(nil, ts),
+	}
+	return oauth2.ReuseTokenSource(nil, imp), nil
+}
+
+// Subject token file types.
+const (
+	fileTypeText = "text"
+	fileTypeJSON = "json"
+)
+
+type format struct {
+	// Type is either "text" or "json". When not provided "text" type is assumed.
+	Type string `json:"type"`
+	// SubjectTokenFieldName is only required for JSON format. This would be "access_token" for azure.
+	SubjectTokenFieldName string `json:"subject_token_field_name"`
+}
+
+// CredentialSource stores the information necessary to retrieve the credentials for the STS exchange.
+// Either the File or the URL field should be filled, depending on the kind of credential in question.
+// The EnvironmentID should start with AWS if being used for an AWS credential.
+type CredentialSource struct {
+	File string `json:"file"`
+
+	URL     string            `json:"url"`
+	Headers map[string]string `json:"headers"`
+
+	EnvironmentID               string `json:"environment_id"`
+	RegionURL                   string `json:"region_url"`
+	RegionalCredVerificationURL string `json:"regional_cred_verification_url"`
+	CredVerificationURL         string `json:"cred_verification_url"`
+	Format                      format `json:"format"`
+}
+
+// parse determines the type of CredentialSource needed
+func (c *Config) parse(ctx context.Context) (baseCredentialSource, error) {
+	if len(c.CredentialSource.EnvironmentID) > 3 && c.CredentialSource.EnvironmentID[:3] == "aws" {
+		if awsVersion, err := strconv.Atoi(c.CredentialSource.EnvironmentID[3:]); err == nil {
+			if awsVersion != 1 {
+				return nil, fmt.Errorf("oauth2/google: aws version '%d' is not supported in the current build", awsVersion)
+			}
+			return awsCredentialSource{
+				EnvironmentID:               c.CredentialSource.EnvironmentID,
+				RegionURL:                   c.CredentialSource.RegionURL,
+				RegionalCredVerificationURL: c.CredentialSource.RegionalCredVerificationURL,
+				CredVerificationURL:         c.CredentialSource.URL,
+				TargetResource:              c.Audience,
+				ctx:                         ctx,
+			}, nil
+		}
+	} else if c.CredentialSource.File != "" {
+		return fileCredentialSource{File: c.CredentialSource.File, Format: c.CredentialSource.Format}, nil
+	} else if c.CredentialSource.URL != "" {
+		return urlCredentialSource{URL: c.CredentialSource.URL, Headers: c.CredentialSource.Headers, Format: c.CredentialSource.Format, ctx: ctx}, nil
+	}
+	return nil, fmt.Errorf("oauth2/google: unable to parse credential source")
+}
+
+type baseCredentialSource interface {
+	subjectToken() (string, error)
+}
+
+// tokenSource is the source that handles external credentials. It is used to retrieve Tokens.
+type tokenSource struct {
+	ctx  context.Context
+	conf *Config
+}
+
+// Token allows tokenSource to conform to the oauth2.TokenSource interface.
+func (ts tokenSource) Token() (*oauth2.Token, error) {
+	conf := ts.conf
+
+	credSource, err := conf.parse(ts.ctx)
+	if err != nil {
+		return nil, err
+	}
+	subjectToken, err := credSource.subjectToken()
+
+	if err != nil {
+		return nil, err
+	}
+	stsRequest := stsTokenExchangeRequest{
+		GrantType:          "urn:ietf:params:oauth:grant-type:token-exchange",
+		Audience:           conf.Audience,
+		Scope:              conf.Scopes,
+		RequestedTokenType: "urn:ietf:params:oauth:token-type:access_token",
+		SubjectToken:       subjectToken,
+		SubjectTokenType:   conf.SubjectTokenType,
+	}
+	header := make(http.Header)
+	header.Add("Content-Type", "application/x-www-form-urlencoded")
+	clientAuth := clientAuthentication{
+		AuthStyle:    oauth2.AuthStyleInHeader,
+		ClientID:     conf.ClientID,
+		ClientSecret: conf.ClientSecret,
+	}
+	var options map[string]interface{}
+	// Do not pass workforce_pool_user_project when client authentication is used.
+	// The client ID is sufficient for determining the user project.
+	if conf.WorkforcePoolUserProject != "" && conf.ClientID == "" {
+		options = map[string]interface{}{
+			"userProject": conf.WorkforcePoolUserProject,
+		}
+	}
+	stsResp, err := exchangeToken(ts.ctx, conf.TokenURL, &stsRequest, clientAuth, header, options)
+	if err != nil {
+		return nil, err
+	}
+
+	accessToken := &oauth2.Token{
+		AccessToken: stsResp.AccessToken,
+		TokenType:   stsResp.TokenType,
+	}
+	if stsResp.ExpiresIn < 0 {
+		return nil, fmt.Errorf("oauth2/google: got invalid expiry from security token service")
+	} else if stsResp.ExpiresIn >= 0 {
+		accessToken.Expiry = now().Add(time.Duration(stsResp.ExpiresIn) * time.Second)
+	}
+
+	if stsResp.RefreshToken != "" {
+		accessToken.RefreshToken = stsResp.RefreshToken
+	}
+	return accessToken, nil
+}
--- a/vendor/golang.org/x/oauth2/google/internal/externalaccount/clientauth.go
+++ b/vendor/golang.org/x/oauth2/google/internal/externalaccount/clientauth.go
@@ -0,0 +1,45 @@
+// Copyright 2020 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 externalaccount
+
+import (
+	"encoding/base64"
+	"net/http"
+	"net/url"
+
+	"golang.org/x/oauth2"
+)
+
+// clientAuthentication represents an OAuth client ID and secret and the mechanism for passing these credentials as stated in rfc6749#2.3.1.
+type clientAuthentication struct {
+	// AuthStyle can be either basic or request-body
+	AuthStyle    oauth2.AuthStyle
+	ClientID     string
+	ClientSecret string
+}
+
+// InjectAuthentication is used to add authentication to a Secure Token Service exchange
+// request.  It modifies either the passed url.Values or http.Header depending on the desired
+// authentication format.
+func (c *clientAuthentication) InjectAuthentication(values url.Values, headers http.Header) {
+	if c.ClientID == "" || c.ClientSecret == "" || values == nil || headers == nil {
+		return
+	}
+
+	switch c.AuthStyle {
+	case oauth2.AuthStyleInHeader: // AuthStyleInHeader corresponds to basic authentication as defined in rfc7617#2
+		plainHeader := c.ClientID + ":" + c.ClientSecret
+		headers.Add("Authorization", "Basic "+base64.StdEncoding.EncodeToString([]byte(plainHeader)))
+	case oauth2.AuthStyleInParams: // AuthStyleInParams corresponds to request-body authentication with ClientID and ClientSecret in the message body.
+		values.Set("client_id", c.ClientID)
+		values.Set("client_secret", c.ClientSecret)
+	case oauth2.AuthStyleAutoDetect:
+		values.Set("client_id", c.ClientID)
+		values.Set("client_secret", c.ClientSecret)
+	default:
+		values.Set("client_id", c.ClientID)
+		values.Set("client_secret", c.ClientSecret)
+	}
+}
--- a/vendor/golang.org/x/oauth2/google/internal/externalaccount/err.go
+++ b/vendor/golang.org/x/oauth2/google/internal/externalaccount/err.go
@@ -0,0 +1,18 @@
+// Copyright 2020 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 externalaccount
+
+import "fmt"
+
+// Error for handling OAuth related error responses as stated in rfc6749#5.2.
+type Error struct {
+	Code        string
+	URI         string
+	Description string
+}
+
+func (err *Error) Error() string {
+	return fmt.Sprintf("got error code %s from %s: %s", err.Code, err.URI, err.Description)
+}
--- a/vendor/golang.org/x/oauth2/google/internal/externalaccount/filecredsource.go
+++ b/vendor/golang.org/x/oauth2/google/internal/externalaccount/filecredsource.go
@@ -0,0 +1,57 @@
+// Copyright 2020 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 externalaccount
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+)
+
+type fileCredentialSource struct {
+	File   string
+	Format format
+}
+
+func (cs fileCredentialSource) subjectToken() (string, error) {
+	tokenFile, err := os.Open(cs.File)
+	if err != nil {
+		return "", fmt.Errorf("oauth2/google: failed to open credential file %q", cs.File)
+	}
+	defer tokenFile.Close()
+	tokenBytes, err := ioutil.ReadAll(io.LimitReader(tokenFile, 1<<20))
+	if err != nil {
+		return "", fmt.Errorf("oauth2/google: failed to read credential file: %v", err)
+	}
+	tokenBytes = bytes.TrimSpace(tokenBytes)
+	switch cs.Format.Type {
+	case "json":
+		jsonData := make(map[string]interface{})
+		err = json.Unmarshal(tokenBytes, &jsonData)
+		if err != nil {
+			return "", fmt.Errorf("oauth2/google: failed to unmarshal subject token file: %v", err)
+		}
+		val, ok := jsonData[cs.Format.SubjectTokenFieldName]
+		if !ok {
+			return "", errors.New("oauth2/google: provided subject_token_field_name not found in credentials")
+		}
+		token, ok := val.(string)
+		if !ok {
+			return "", errors.New("oauth2/google: improperly formatted subject token")
+		}
+		return token, nil
+	case "text":
+		return string(tokenBytes), nil
+	case "":
+		return string(tokenBytes), nil
+	default:
+		return "", errors.New("oauth2/google: invalid credential_source file format type")
+	}
+
+}
--- a/vendor/golang.org/x/oauth2/google/internal/externalaccount/impersonate.go
+++ b/vendor/golang.org/x/oauth2/google/internal/externalaccount/impersonate.go
@@ -0,0 +1,98 @@
+// Copyright 2021 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 externalaccount
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"time"
+
+	"golang.org/x/oauth2"
+)
+
+// generateAccesstokenReq is used for service account impersonation
+type generateAccessTokenReq struct {
+	Delegates []string `json:"delegates,omitempty"`
+	Lifetime  string   `json:"lifetime,omitempty"`
+	Scope     []string `json:"scope,omitempty"`
+}
+
+type impersonateTokenResponse struct {
+	AccessToken string `json:"accessToken"`
+	ExpireTime  string `json:"expireTime"`
+}
+
+// ImpersonateTokenSource uses a source credential, stored in Ts, to request an access token to the provided URL.
+// Scopes can be defined when the access token is requested.
+type ImpersonateTokenSource struct {
+	// Ctx is the execution context of the impersonation process
+	// used to perform http call to the URL. Required
+	Ctx context.Context
+	// Ts is the source credential used to generate a token on the
+	// impersonated service account. Required.
+	Ts oauth2.TokenSource
+
+	// URL is the endpoint to call to generate a token
+	// on behalf the service account. Required.
+	URL string
+	// Scopes that the impersonated credential should have. Required.
+	Scopes []string
+	// Delegates are the service account email addresses in a delegation chain.
+	// Each service account must be granted roles/iam.serviceAccountTokenCreator
+	// on the next service account in the chain. Optional.
+	Delegates []string
+}
+
+// Token performs the exchange to get a temporary service account token to allow access to GCP.
+func (its ImpersonateTokenSource) Token() (*oauth2.Token, error) {
+	reqBody := generateAccessTokenReq{
+		Lifetime:  "3600s",
+		Scope:     its.Scopes,
+		Delegates: its.Delegates,
+	}
+	b, err := json.Marshal(reqBody)
+	if err != nil {
+		return nil, fmt.Errorf("oauth2/google: unable to marshal request: %v", err)
+	}
+	client := oauth2.NewClient(its.Ctx, its.Ts)
+	req, err := http.NewRequest("POST", its.URL, bytes.NewReader(b))
+	if err != nil {
+		return nil, fmt.Errorf("oauth2/google: unable to create impersonation request: %v", err)
+	}
+	req = req.WithContext(its.Ctx)
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("oauth2/google: unable to generate access token: %v", err)
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	if err != nil {
+		return nil, fmt.Errorf("oauth2/google: unable to read body: %v", err)
+	}
+	if c := resp.StatusCode; c < 200 || c > 299 {
+		return nil, fmt.Errorf("oauth2/google: status code %d: %s", c, body)
+	}
+
+	var accessTokenResp impersonateTokenResponse
+	if err := json.Unmarshal(body, &accessTokenResp); err != nil {
+		return nil, fmt.Errorf("oauth2/google: unable to parse response: %v", err)
+	}
+	expiry, err := time.Parse(time.RFC3339, accessTokenResp.ExpireTime)
+	if err != nil {
+		return nil, fmt.Errorf("oauth2/google: unable to parse expiry: %v", err)
+	}
+	return &oauth2.Token{
+		AccessToken: accessTokenResp.AccessToken,
+		Expiry:      expiry,
+		TokenType:   "Bearer",
+	}, nil
+}
--- a/vendor/golang.org/x/oauth2/google/internal/externalaccount/sts_exchange.go
+++ b/vendor/golang.org/x/oauth2/google/internal/externalaccount/sts_exchange.go
@@ -0,0 +1,107 @@
+// Copyright 2020 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 externalaccount
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"golang.org/x/oauth2"
+)
+
+// exchangeToken performs an oauth2 token exchange with the provided endpoint.
+// The first 4 fields are all mandatory.  headers can be used to pass additional
+// headers beyond the bare minimum required by the token exchange.  options can
+// be used to pass additional JSON-structured options to the remote server.
+func exchangeToken(ctx context.Context, endpoint string, request *stsTokenExchangeRequest, authentication clientAuthentication, headers http.Header, options map[string]interface{}) (*stsTokenExchangeResponse, error) {
+
+	client := oauth2.NewClient(ctx, nil)
+
+	data := url.Values{}
+	data.Set("audience", request.Audience)
+	data.Set("grant_type", "urn:ietf:params:oauth:grant-type:token-exchange")
+	data.Set("requested_token_type", "urn:ietf:params:oauth:token-type:access_token")
+	data.Set("subject_token_type", request.SubjectTokenType)
+	data.Set("subject_token", request.SubjectToken)
+	data.Set("scope", strings.Join(request.Scope, " "))
+	if options != nil {
+		opts, err := json.Marshal(options)
+		if err != nil {
+			return nil, fmt.Errorf("oauth2/google: failed to marshal additional options: %v", err)
+		}
+		data.Set("options", string(opts))
+	}
+
+	authentication.InjectAuthentication(data, headers)
+	encodedData := data.Encode()
+
+	req, err := http.NewRequest("POST", endpoint, strings.NewReader(encodedData))
+	if err != nil {
+		return nil, fmt.Errorf("oauth2/google: failed to properly build http request: %v", err)
+
+	}
+	req = req.WithContext(ctx)
+	for key, list := range headers {
+		for _, val := range list {
+			req.Header.Add(key, val)
+		}
+	}
+	req.Header.Add("Content-Length", strconv.Itoa(len(encodedData)))
+
+	resp, err := client.Do(req)
+
+	if err != nil {
+		return nil, fmt.Errorf("oauth2/google: invalid response from Secure Token Server: %v", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := ioutil.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	if err != nil {
+		return nil, err
+	}
+	if c := resp.StatusCode; c < 200 || c > 299 {
+		return nil, fmt.Errorf("oauth2/google: status code %d: %s", c, body)
+	}
+	var stsResp stsTokenExchangeResponse
+	err = json.Unmarshal(body, &stsResp)
+	if err != nil {
+		return nil, fmt.Errorf("oauth2/google: failed to unmarshal response body from Secure Token Server: %v", err)
+
+	}
+
+	return &stsResp, nil
+}
+
+// stsTokenExchangeRequest contains fields necessary to make an oauth2 token exchange.
+type stsTokenExchangeRequest struct {
+	ActingParty struct {
+		ActorToken     string
+		ActorTokenType string
+	}
+	GrantType          string
+	Resource           string
+	Audience           string
+	Scope              []string
+	RequestedTokenType string
+	SubjectToken       string
+	SubjectTokenType   string
+}
+
+// stsTokenExchangeResponse is used to decode the remote server response during an oauth2 token exchange.
+type stsTokenExchangeResponse struct {
+	AccessToken     string `json:"access_token"`
+	IssuedTokenType string `json:"issued_token_type"`
+	TokenType       string `json:"token_type"`
+	ExpiresIn       int    `json:"expires_in"`
+	Scope           string `json:"scope"`
+	RefreshToken    string `json:"refresh_token"`
+}
--- a/vendor/golang.org/x/oauth2/google/internal/externalaccount/urlcredsource.go
+++ b/vendor/golang.org/x/oauth2/google/internal/externalaccount/urlcredsource.go
@@ -0,0 +1,75 @@
+// Copyright 2020 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 externalaccount
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+
+	"golang.org/x/oauth2"
+)
+
+type urlCredentialSource struct {
+	URL     string
+	Headers map[string]string
+	Format  format
+	ctx     context.Context
+}
+
+func (cs urlCredentialSource) subjectToken() (string, error) {
+	client := oauth2.NewClient(cs.ctx, nil)
+	req, err := http.NewRequest("GET", cs.URL, nil)
+	if err != nil {
+		return "", fmt.Errorf("oauth2/google: HTTP request for URL-sourced credential failed: %v", err)
+	}
+	req = req.WithContext(cs.ctx)
+
+	for key, val := range cs.Headers {
+		req.Header.Add(key, val)
+	}
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("oauth2/google: invalid response when retrieving subject token: %v", err)
+	}
+	defer resp.Body.Close()
+
+	respBody, err := ioutil.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	if err != nil {
+		return "", fmt.Errorf("oauth2/google: invalid body in subject token URL query: %v", err)
+	}
+	if c := resp.StatusCode; c < 200 || c > 299 {
+		return "", fmt.Errorf("oauth2/google: status code %d: %s", c, respBody)
+	}
+
+	switch cs.Format.Type {
+	case "json":
+		jsonData := make(map[string]interface{})
+		err = json.Unmarshal(respBody, &jsonData)
+		if err != nil {
+			return "", fmt.Errorf("oauth2/google: failed to unmarshal subject token file: %v", err)
+		}
+		val, ok := jsonData[cs.Format.SubjectTokenFieldName]
+		if !ok {
+			return "", errors.New("oauth2/google: provided subject_token_field_name not found in credentials")
+		}
+		token, ok := val.(string)
+		if !ok {
+			return "", errors.New("oauth2/google: improperly formatted subject token")
+		}
+		return token, nil
+	case "text":
+		return string(respBody), nil
+	case "":
+		return string(respBody), nil
+	default:
+		return "", errors.New("oauth2/google: invalid credential_source file format type")
+	}
+
+}
--- a/vendor/golang.org/x/oauth2/google/jwt.go
+++ b/vendor/golang.org/x/oauth2/google/jwt.go
@@ -0,0 +1,101 @@
+// 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 google
+
+import (
+	"crypto/rsa"
+	"fmt"
+	"strings"
+	"time"
+
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/internal"
+	"golang.org/x/oauth2/jws"
+)
+
+// JWTAccessTokenSourceFromJSON uses a Google Developers service account JSON
+// key file to read the credentials that authorize and authenticate the
+// requests, and returns a TokenSource that does not use any OAuth2 flow but
+// instead creates a JWT and sends that as the access token.
+// The audience is typically a URL that specifies the scope of the credentials.
+//
+// Note that this is not a standard OAuth flow, but rather an
+// optimization supported by a few Google services.
+// Unless you know otherwise, you should use JWTConfigFromJSON instead.
+func JWTAccessTokenSourceFromJSON(jsonKey []byte, audience string) (oauth2.TokenSource, error) {
+	return newJWTSource(jsonKey, audience, nil)
+}
+
+// JWTAccessTokenSourceWithScope uses a Google Developers service account JSON
+// key file to read the credentials that authorize and authenticate the
+// requests, and returns a TokenSource that does not use any OAuth2 flow but
+// instead creates a JWT and sends that as the access token.
+// The scope is typically a list of URLs that specifies the scope of the
+// credentials.
+//
+// Note that this is not a standard OAuth flow, but rather an
+// optimization supported by a few Google services.
+// Unless you know otherwise, you should use JWTConfigFromJSON instead.
+func JWTAccessTokenSourceWithScope(jsonKey []byte, scope ...string) (oauth2.TokenSource, error) {
+	return newJWTSource(jsonKey, "", scope)
+}
+
+func newJWTSource(jsonKey []byte, audience string, scopes []string) (oauth2.TokenSource, error) {
+	if len(scopes) == 0 && audience == "" {
+		return nil, fmt.Errorf("google: missing scope/audience for JWT access token")
+	}
+
+	cfg, err := JWTConfigFromJSON(jsonKey)
+	if err != nil {
+		return nil, fmt.Errorf("google: could not parse JSON key: %v", err)
+	}
+	pk, err := internal.ParseKey(cfg.PrivateKey)
+	if err != nil {
+		return nil, fmt.Errorf("google: could not parse key: %v", err)
+	}
+	ts := &jwtAccessTokenSource{
+		email:    cfg.Email,
+		audience: audience,
+		scopes:   scopes,
+		pk:       pk,
+		pkID:     cfg.PrivateKeyID,
+	}
+	tok, err := ts.Token()
+	if err != nil {
+		return nil, err
+	}
+	return oauth2.ReuseTokenSource(tok, ts), nil
+}
+
+type jwtAccessTokenSource struct {
+	email, audience string
+	scopes          []string
+	pk              *rsa.PrivateKey
+	pkID            string
+}
+
+func (ts *jwtAccessTokenSource) Token() (*oauth2.Token, error) {
+	iat := time.Now()
+	exp := iat.Add(time.Hour)
+	scope := strings.Join(ts.scopes, " ")
+	cs := &jws.ClaimSet{
+		Iss:   ts.email,
+		Sub:   ts.email,
+		Aud:   ts.audience,
+		Scope: scope,
+		Iat:   iat.Unix(),
+		Exp:   exp.Unix(),
+	}
+	hdr := &jws.Header{
+		Algorithm: "RS256",
+		Typ:       "JWT",
+		KeyID:     string(ts.pkID),
+	}
+	msg, err := jws.Encode(hdr, cs, ts.pk)
+	if err != nil {
+		return nil, fmt.Errorf("google: could not encode JWT: %v", err)
+	}
+	return &oauth2.Token{AccessToken: msg, TokenType: "Bearer", Expiry: exp}, nil
+}
--- a/vendor/golang.org/x/oauth2/google/sdk.go
+++ b/vendor/golang.org/x/oauth2/google/sdk.go
@@ -0,0 +1,201 @@
+// 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 google
+
+import (
+	"bufio"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"os/user"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"time"
+
+	"golang.org/x/oauth2"
+)
+
+type sdkCredentials struct {
+	Data []struct {
+		Credential struct {
+			ClientID     string     `json:"client_id"`
+			ClientSecret string     `json:"client_secret"`
+			AccessToken  string     `json:"access_token"`
+			RefreshToken string     `json:"refresh_token"`
+			TokenExpiry  *time.Time `json:"token_expiry"`
+		} `json:"credential"`
+		Key struct {
+			Account string `json:"account"`
+			Scope   string `json:"scope"`
+		} `json:"key"`
+	}
+}
+
+// An SDKConfig provides access to tokens from an account already
+// authorized via the Google Cloud SDK.
+type SDKConfig struct {
+	conf         oauth2.Config
+	initialToken *oauth2.Token
+}
+
+// NewSDKConfig creates an SDKConfig for the given Google Cloud SDK
+// account. If account is empty, the account currently active in
+// Google Cloud SDK properties is used.
+// Google Cloud SDK credentials must be created by running `gcloud auth`
+// before using this function.
+// The Google Cloud SDK is available at https://cloud.google.com/sdk/.
+func NewSDKConfig(account string) (*SDKConfig, error) {
+	configPath, err := sdkConfigPath()
+	if err != nil {
+		return nil, fmt.Errorf("oauth2/google: error getting SDK config path: %v", err)
+	}
+	credentialsPath := filepath.Join(configPath, "credentials")
+	f, err := os.Open(credentialsPath)
+	if err != nil {
+		return nil, fmt.Errorf("oauth2/google: failed to load SDK credentials: %v", err)
+	}
+	defer f.Close()
+
+	var c sdkCredentials
+	if err := json.NewDecoder(f).Decode(&c); err != nil {
+		return nil, fmt.Errorf("oauth2/google: failed to decode SDK credentials from %q: %v", credentialsPath, err)
+	}
+	if len(c.Data) == 0 {
+		return nil, fmt.Errorf("oauth2/google: no credentials found in %q, run `gcloud auth login` to create one", credentialsPath)
+	}
+	if account == "" {
+		propertiesPath := filepath.Join(configPath, "properties")
+		f, err := os.Open(propertiesPath)
+		if err != nil {
+			return nil, fmt.Errorf("oauth2/google: failed to load SDK properties: %v", err)
+		}
+		defer f.Close()
+		ini, err := parseINI(f)
+		if err != nil {
+			return nil, fmt.Errorf("oauth2/google: failed to parse SDK properties %q: %v", propertiesPath, err)
+		}
+		core, ok := ini["core"]
+		if !ok {
+			return nil, fmt.Errorf("oauth2/google: failed to find [core] section in %v", ini)
+		}
+		active, ok := core["account"]
+		if !ok {
+			return nil, fmt.Errorf("oauth2/google: failed to find %q attribute in %v", "account", core)
+		}
+		account = active
+	}
+
+	for _, d := range c.Data {
+		if account == "" || d.Key.Account == account {
+			if d.Credential.AccessToken == "" && d.Credential.RefreshToken == "" {
+				return nil, fmt.Errorf("oauth2/google: no token available for account %q", account)
+			}
+			var expiry time.Time
+			if d.Credential.TokenExpiry != nil {
+				expiry = *d.Credential.TokenExpiry
+			}
+			return &SDKConfig{
+				conf: oauth2.Config{
+					ClientID:     d.Credential.ClientID,
+					ClientSecret: d.Credential.ClientSecret,
+					Scopes:       strings.Split(d.Key.Scope, " "),
+					Endpoint:     Endpoint,
+					RedirectURL:  "oob",
+				},
+				initialToken: &oauth2.Token{
+					AccessToken:  d.Credential.AccessToken,
+					RefreshToken: d.Credential.RefreshToken,
+					Expiry:       expiry,
+				},
+			}, nil
+		}
+	}
+	return nil, fmt.Errorf("oauth2/google: no such credentials for account %q", account)
+}
+
+// Client returns an HTTP client using Google Cloud SDK credentials to
+// authorize requests. The token will auto-refresh as necessary. The
+// underlying http.RoundTripper will be obtained using the provided
+// context. The returned client and its Transport should not be
+// modified.
+func (c *SDKConfig) Client(ctx context.Context) *http.Client {
+	return &http.Client{
+		Transport: &oauth2.Transport{
+			Source: c.TokenSource(ctx),
+		},
+	}
+}
+
+// TokenSource returns an oauth2.TokenSource that retrieve tokens from
+// Google Cloud SDK credentials using the provided context.
+// It will returns the current access token stored in the credentials,
+// and refresh it when it expires, but it won't update the credentials
+// with the new access token.
+func (c *SDKConfig) TokenSource(ctx context.Context) oauth2.TokenSource {
+	return c.conf.TokenSource(ctx, c.initialToken)
+}
+
+// Scopes are the OAuth 2.0 scopes the current account is authorized for.
+func (c *SDKConfig) Scopes() []string {
+	return c.conf.Scopes
+}
+
+func parseINI(ini io.Reader) (map[string]map[string]string, error) {
+	result := map[string]map[string]string{
+		"": {}, // root section
+	}
+	scanner := bufio.NewScanner(ini)
+	currentSection := ""
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if strings.HasPrefix(line, ";") {
+			// comment.
+			continue
+		}
+		if strings.HasPrefix(line, "[") && strings.HasSuffix(line, "]") {
+			currentSection = strings.TrimSpace(line[1 : len(line)-1])
+			result[currentSection] = map[string]string{}
+			continue
+		}
+		parts := strings.SplitN(line, "=", 2)
+		if len(parts) == 2 && parts[0] != "" {
+			result[currentSection][strings.TrimSpace(parts[0])] = strings.TrimSpace(parts[1])
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return nil, fmt.Errorf("error scanning ini: %v", err)
+	}
+	return result, nil
+}
+
+// sdkConfigPath tries to guess where the gcloud config is located.
+// It can be overridden during tests.
+var sdkConfigPath = func() (string, error) {
+	if runtime.GOOS == "windows" {
+		return filepath.Join(os.Getenv("APPDATA"), "gcloud"), nil
+	}
+	homeDir := guessUnixHomeDir()
+	if homeDir == "" {
+		return "", errors.New("unable to get current user home directory: os/user lookup failed; $HOME is empty")
+	}
+	return filepath.Join(homeDir, ".config", "gcloud"), nil
+}
+
+func guessUnixHomeDir() string {
+	// Prefer $HOME over user.Current due to glibc bug: golang.org/issue/13470
+	if v := os.Getenv("HOME"); v != "" {
+		return v
+	}
+	// Else, fall back to user.Current:
+	if u, err := user.Current(); err == nil {
+		return u.HomeDir
+	}
+	return ""
+}
--- a/vendor/golang.org/x/oauth2/jws/jws.go
+++ b/vendor/golang.org/x/oauth2/jws/jws.go
@@ -0,0 +1,182 @@
+// Copyright 2014 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 jws provides a partial implementation
+// of JSON Web Signature encoding and decoding.
+// It exists to support the golang.org/x/oauth2 package.
+//
+// See RFC 7515.
+//
+// Deprecated: this package is not intended for public use and might be
+// removed in the future. It exists for internal use only.
+// Please switch to another JWS package or copy this package into your own
+// source tree.
+package jws // import "golang.org/x/oauth2/jws"
+
+import (
+	"bytes"
+	"crypto"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+)
+
+// ClaimSet contains information about the JWT signature including the
+// permissions being requested (scopes), the target of the token, the issuer,
+// the time the token was issued, and the lifetime of the token.
+type ClaimSet struct {
+	Iss   string `json:"iss"`             // email address of the client_id of the application making the access token request
+	Scope string `json:"scope,omitempty"` // space-delimited list of the permissions the application requests
+	Aud   string `json:"aud"`             // descriptor of the intended target of the assertion (Optional).
+	Exp   int64  `json:"exp"`             // the expiration time of the assertion (seconds since Unix epoch)
+	Iat   int64  `json:"iat"`             // the time the assertion was issued (seconds since Unix epoch)
+	Typ   string `json:"typ,omitempty"`   // token type (Optional).
+
+	// Email for which the application is requesting delegated access (Optional).
+	Sub string `json:"sub,omitempty"`
+
+	// The old name of Sub. Client keeps setting Prn to be
+	// complaint with legacy OAuth 2.0 providers. (Optional)
+	Prn string `json:"prn,omitempty"`
+
+	// See http://tools.ietf.org/html/draft-jones-json-web-token-10#section-4.3
+	// This array is marshalled using custom code (see (c *ClaimSet) encode()).
+	PrivateClaims map[string]interface{} `json:"-"`
+}
+
+func (c *ClaimSet) encode() (string, error) {
+	// Reverting time back for machines whose time is not perfectly in sync.
+	// If client machine's time is in the future according
+	// to Google servers, an access token will not be issued.
+	now := time.Now().Add(-10 * time.Second)
+	if c.Iat == 0 {
+		c.Iat = now.Unix()
+	}
+	if c.Exp == 0 {
+		c.Exp = now.Add(time.Hour).Unix()
+	}
+	if c.Exp < c.Iat {
+		return "", fmt.Errorf("jws: invalid Exp = %v; must be later than Iat = %v", c.Exp, c.Iat)
+	}
+
+	b, err := json.Marshal(c)
+	if err != nil {
+		return "", err
+	}
+
+	if len(c.PrivateClaims) == 0 {
+		return base64.RawURLEncoding.EncodeToString(b), nil
+	}
+
+	// Marshal private claim set and then append it to b.
+	prv, err := json.Marshal(c.PrivateClaims)
+	if err != nil {
+		return "", fmt.Errorf("jws: invalid map of private claims %v", c.PrivateClaims)
+	}
+
+	// Concatenate public and private claim JSON objects.
+	if !bytes.HasSuffix(b, []byte{'}'}) {
+		return "", fmt.Errorf("jws: invalid JSON %s", b)
+	}
+	if !bytes.HasPrefix(prv, []byte{'{'}) {
+		return "", fmt.Errorf("jws: invalid JSON %s", prv)
+	}
+	b[len(b)-1] = ','         // Replace closing curly brace with a comma.
+	b = append(b, prv[1:]...) // Append private claims.
+	return base64.RawURLEncoding.EncodeToString(b), nil
+}
+
+// Header represents the header for the signed JWS payloads.
+type Header struct {
+	// The algorithm used for signature.
+	Algorithm string `json:"alg"`
+
+	// Represents the token type.
+	Typ string `json:"typ"`
+
+	// The optional hint of which key is being used.
+	KeyID string `json:"kid,omitempty"`
+}
+
+func (h *Header) encode() (string, error) {
+	b, err := json.Marshal(h)
+	if err != nil {
+		return "", err
+	}
+	return base64.RawURLEncoding.EncodeToString(b), nil
+}
+
+// Decode decodes a claim set from a JWS payload.
+func Decode(payload string) (*ClaimSet, error) {
+	// decode returned id token to get expiry
+	s := strings.Split(payload, ".")
+	if len(s) < 2 {
+		// TODO(jbd): Provide more context about the error.
+		return nil, errors.New("jws: invalid token received")
+	}
+	decoded, err := base64.RawURLEncoding.DecodeString(s[1])
+	if err != nil {
+		return nil, err
+	}
+	c := &ClaimSet{}
+	err = json.NewDecoder(bytes.NewBuffer(decoded)).Decode(c)
+	return c, err
+}
+
+// Signer returns a signature for the given data.
+type Signer func(data []byte) (sig []byte, err error)
+
+// EncodeWithSigner encodes a header and claim set with the provided signer.
+func EncodeWithSigner(header *Header, c *ClaimSet, sg Signer) (string, error) {
+	head, err := header.encode()
+	if err != nil {
+		return "", err
+	}
+	cs, err := c.encode()
+	if err != nil {
+		return "", err
+	}
+	ss := fmt.Sprintf("%s.%s", head, cs)
+	sig, err := sg([]byte(ss))
+	if err != nil {
+		return "", err
+	}
+	return fmt.Sprintf("%s.%s", ss, base64.RawURLEncoding.EncodeToString(sig)), nil
+}
+
+// Encode encodes a signed JWS with provided header and claim set.
+// This invokes EncodeWithSigner using crypto/rsa.SignPKCS1v15 with the given RSA private key.
+func Encode(header *Header, c *ClaimSet, key *rsa.PrivateKey) (string, error) {
+	sg := func(data []byte) (sig []byte, err error) {
+		h := sha256.New()
+		h.Write(data)
+		return rsa.SignPKCS1v15(rand.Reader, key, crypto.SHA256, h.Sum(nil))
+	}
+	return EncodeWithSigner(header, c, sg)
+}
+
+// Verify tests whether the provided JWT token's signature was produced by the private key
+// associated with the supplied public key.
+func Verify(token string, key *rsa.PublicKey) error {
+	parts := strings.Split(token, ".")
+	if len(parts) != 3 {
+		return errors.New("jws: invalid token received, token must have 3 parts")
+	}
+
+	signedContent := parts[0] + "." + parts[1]
+	signatureString, err := base64.RawURLEncoding.DecodeString(parts[2])
+	if err != nil {
+		return err
+	}
+
+	h := sha256.New()
+	h.Write([]byte(signedContent))
+	return rsa.VerifyPKCS1v15(key, crypto.SHA256, h.Sum(nil), []byte(signatureString))
+}
--- a/vendor/golang.org/x/oauth2/jwt/jwt.go
+++ b/vendor/golang.org/x/oauth2/jwt/jwt.go
@@ -0,0 +1,185 @@
+// Copyright 2014 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 jwt implements the OAuth 2.0 JSON Web Token flow, commonly
+// known as "two-legged OAuth 2.0".
+//
+// See: https://tools.ietf.org/html/draft-ietf-oauth-jwt-bearer-12
+package jwt
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/internal"
+	"golang.org/x/oauth2/jws"
+)
+
+var (
+	defaultGrantType = "urn:ietf:params:oauth:grant-type:jwt-bearer"
+	defaultHeader    = &jws.Header{Algorithm: "RS256", Typ: "JWT"}
+)
+
+// Config is the configuration for using JWT to fetch tokens,
+// commonly known as "two-legged OAuth 2.0".
+type Config struct {
+	// Email is the OAuth client identifier used when communicating with
+	// the configured OAuth provider.
+	Email string
+
+	// PrivateKey contains the contents of an RSA private key or the
+	// contents of a PEM file that contains a private key. The provided
+	// private key is used to sign JWT payloads.
+	// PEM containers with a passphrase are not supported.
+	// Use the following command to convert a PKCS 12 file into a PEM.
+	//
+	//    $ openssl pkcs12 -in key.p12 -out key.pem -nodes
+	//
+	PrivateKey []byte
+
+	// PrivateKeyID contains an optional hint indicating which key is being
+	// used.
+	PrivateKeyID string
+
+	// Subject is the optional user to impersonate.
+	Subject string
+
+	// Scopes optionally specifies a list of requested permission scopes.
+	Scopes []string
+
+	// TokenURL is the endpoint required to complete the 2-legged JWT flow.
+	TokenURL string
+
+	// Expires optionally specifies how long the token is valid for.
+	Expires time.Duration
+
+	// Audience optionally specifies the intended audience of the
+	// request.  If empty, the value of TokenURL is used as the
+	// intended audience.
+	Audience string
+
+	// PrivateClaims optionally specifies custom private claims in the JWT.
+	// See http://tools.ietf.org/html/draft-jones-json-web-token-10#section-4.3
+	PrivateClaims map[string]interface{}
+
+	// UseIDToken optionally specifies whether ID token should be used instead
+	// of access token when the server returns both.
+	UseIDToken bool
+}
+
+// TokenSource returns a JWT TokenSource using the configuration
+// in c and the HTTP client from the provided context.
+func (c *Config) TokenSource(ctx context.Context) oauth2.TokenSource {
+	return oauth2.ReuseTokenSource(nil, jwtSource{ctx, c})
+}
+
+// Client returns an HTTP client wrapping the context's
+// HTTP transport and adding Authorization headers with tokens
+// obtained from c.
+//
+// The returned client and its Transport should not be modified.
+func (c *Config) Client(ctx context.Context) *http.Client {
+	return oauth2.NewClient(ctx, c.TokenSource(ctx))
+}
+
+// jwtSource is a source that always does a signed JWT request for a token.
+// It should typically be wrapped with a reuseTokenSource.
+type jwtSource struct {
+	ctx  context.Context
+	conf *Config
+}
+
+func (js jwtSource) Token() (*oauth2.Token, error) {
+	pk, err := internal.ParseKey(js.conf.PrivateKey)
+	if err != nil {
+		return nil, err
+	}
+	hc := oauth2.NewClient(js.ctx, nil)
+	claimSet := &jws.ClaimSet{
+		Iss:           js.conf.Email,
+		Scope:         strings.Join(js.conf.Scopes, " "),
+		Aud:           js.conf.TokenURL,
+		PrivateClaims: js.conf.PrivateClaims,
+	}
+	if subject := js.conf.Subject; subject != "" {
+		claimSet.Sub = subject
+		// prn is the old name of sub. Keep setting it
+		// to be compatible with legacy OAuth 2.0 providers.
+		claimSet.Prn = subject
+	}
+	if t := js.conf.Expires; t > 0 {
+		claimSet.Exp = time.Now().Add(t).Unix()
+	}
+	if aud := js.conf.Audience; aud != "" {
+		claimSet.Aud = aud
+	}
+	h := *defaultHeader
+	h.KeyID = js.conf.PrivateKeyID
+	payload, err := jws.Encode(&h, claimSet, pk)
+	if err != nil {
+		return nil, err
+	}
+	v := url.Values{}
+	v.Set("grant_type", defaultGrantType)
+	v.Set("assertion", payload)
+	resp, err := hc.PostForm(js.conf.TokenURL, v)
+	if err != nil {
+		return nil, fmt.Errorf("oauth2: cannot fetch token: %v", err)
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(io.LimitReader(resp.Body, 1<<20))
+	if err != nil {
+		return nil, fmt.Errorf("oauth2: cannot fetch token: %v", err)
+	}
+	if c := resp.StatusCode; c < 200 || c > 299 {
+		return nil, &oauth2.RetrieveError{
+			Response: resp,
+			Body:     body,
+		}
+	}
+	// tokenRes is the JSON response body.
+	var tokenRes struct {
+		AccessToken string `json:"access_token"`
+		TokenType   string `json:"token_type"`
+		IDToken     string `json:"id_token"`
+		ExpiresIn   int64  `json:"expires_in"` // relative seconds from now
+	}
+	if err := json.Unmarshal(body, &tokenRes); err != nil {
+		return nil, fmt.Errorf("oauth2: cannot fetch token: %v", err)
+	}
+	token := &oauth2.Token{
+		AccessToken: tokenRes.AccessToken,
+		TokenType:   tokenRes.TokenType,
+	}
+	raw := make(map[string]interface{})
+	json.Unmarshal(body, &raw) // no error checks for optional fields
+	token = token.WithExtra(raw)
+
+	if secs := tokenRes.ExpiresIn; secs > 0 {
+		token.Expiry = time.Now().Add(time.Duration(secs) * time.Second)
+	}
+	if v := tokenRes.IDToken; v != "" {
+		// decode returned id token to get expiry
+		claimSet, err := jws.Decode(v)
+		if err != nil {
+			return nil, fmt.Errorf("oauth2: error decoding JWT token: %v", err)
+		}
+		token.Expiry = time.Unix(claimSet.Exp, 0)
+	}
+	if js.conf.UseIDToken {
+		if tokenRes.IDToken == "" {
+			return nil, fmt.Errorf("oauth2: response doesn't have JWT token")
+		}
+		token.AccessToken = tokenRes.IDToken
+	}
+	return token, nil
+}