Add fork of Go 1.15-dev's crypto/x509

Snapshotted from Go commit 619c7a48a38b28b521591b490fd14ccb7ea5e821 (https://go-review.googlesource.com/c/go/+/229762, "crypto/x509: add x509omitbundledroots build tag to not embed roots") With 975c01342a25899962969833d8b2873dc8856a4f (https://go-review.googlesource.com/c/go/+/220721) removed, because it depends on other stuff in Go std that doesn't yet exist in a Go release. Also, add a subset fork of Go's internal/testenv, for use by x509's tests.
2024-11-25 19:15:34 +00:00 · 2020-04-24 20:15:28 -07:00 · 2020-04-24 20:15:28 -07:00 · 3bab226299
commit 3bab226299
parent 2dac4f2b24
36 changed files with 18578 additions and 0 deletions
--- a/tempfork/internal/testenv/testenv.go
+++ b/tempfork/internal/testenv/testenv.go
@ -0,0 +1,160 @@
+// 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 testenv is Tailscale's fork/subset of Go's
+// internal/testenv. It exists to satisfy the tests of our fork of
+// crypto/x509.
+package testenv
+
+import (
+	"errors"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+// HasGoBuild reports whether the current system can build programs with ``go build''
+// and then run them with os.StartProcess or exec.Command.
+func HasGoBuild() bool {
+	if os.Getenv("GO_GCFLAGS") != "" {
+		// It's too much work to require every caller of the go command
+		// to pass along "-gcflags="+os.Getenv("GO_GCFLAGS").
+		// For now, if $GO_GCFLAGS is set, report that we simply can't
+		// run go build.
+		return false
+	}
+	switch runtime.GOOS {
+	case "android", "js":
+		return false
+	case "darwin":
+		if runtime.GOARCH == "arm64" {
+			return false
+		}
+	}
+	return true
+}
+
+// MustHaveGoBuild checks that the current system can build programs with ``go build''
+// and then run them with os.StartProcess or exec.Command.
+// If not, MustHaveGoBuild calls t.Skip with an explanation.
+func MustHaveGoBuild(t testing.TB) {
+	if os.Getenv("GO_GCFLAGS") != "" {
+		t.Skipf("skipping test: 'go build' not compatible with setting $GO_GCFLAGS")
+	}
+	if !HasGoBuild() {
+		t.Skipf("skipping test: 'go build' not available on %s/%s", runtime.GOOS, runtime.GOARCH)
+	}
+}
+
+// HasGoRun reports whether the current system can run programs with ``go run.''
+func HasGoRun() bool {
+	// For now, having go run and having go build are the same.
+	return HasGoBuild()
+}
+
+// MustHaveGoRun checks that the current system can run programs with ``go run.''
+// If not, MustHaveGoRun calls t.Skip with an explanation.
+func MustHaveGoRun(t testing.TB) {
+	if !HasGoRun() {
+		t.Skipf("skipping test: 'go run' not available on %s/%s", runtime.GOOS, runtime.GOARCH)
+	}
+}
+
+// GoTool reports the path to the Go tool.
+func GoTool() (string, error) {
+	if !HasGoBuild() {
+		return "", errors.New("platform cannot run go tool")
+	}
+	var exeSuffix string
+	if runtime.GOOS == "windows" {
+		exeSuffix = ".exe"
+	}
+	path := filepath.Join(runtime.GOROOT(), "bin", "go"+exeSuffix)
+	if _, err := os.Stat(path); err == nil {
+		return path, nil
+	}
+	goBin, err := exec.LookPath("go" + exeSuffix)
+	if err != nil {
+		return "", errors.New("cannot find go tool: " + err.Error())
+	}
+	return goBin, nil
+}
+
+// GoToolPath reports the path to the Go tool.
+// It is a convenience wrapper around GoTool.
+// If the tool is unavailable GoToolPath calls t.Skip.
+// If the tool should be available and isn't, GoToolPath calls t.Fatal.
+func GoToolPath(t testing.TB) string {
+	MustHaveGoBuild(t)
+	path, err := GoTool()
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Add all environment variables that affect the Go command to test metadata.
+	// Cached test results will be invalidate when these variables change.
+	// See golang.org/issue/32285.
+	for _, envVar := range strings.Fields(KnownEnv) {
+		os.Getenv(envVar)
+	}
+	return path
+}
+
+// KnownEnv is a list of environment variables that affect the operation
+// of the Go command.
+const KnownEnv = `
+	AR
+	CC
+	CGO_CFLAGS
+	CGO_CFLAGS_ALLOW
+	CGO_CFLAGS_DISALLOW
+	CGO_CPPFLAGS
+	CGO_CPPFLAGS_ALLOW
+	CGO_CPPFLAGS_DISALLOW
+	CGO_CXXFLAGS
+	CGO_CXXFLAGS_ALLOW
+	CGO_CXXFLAGS_DISALLOW
+	CGO_ENABLED
+	CGO_FFLAGS
+	CGO_FFLAGS_ALLOW
+	CGO_FFLAGS_DISALLOW
+	CGO_LDFLAGS
+	CGO_LDFLAGS_ALLOW
+	CGO_LDFLAGS_DISALLOW
+	CXX
+	FC
+	GCCGO
+	GO111MODULE
+	GO386
+	GOARCH
+	GOARM
+	GOBIN
+	GOCACHE
+	GOENV
+	GOEXE
+	GOFLAGS
+	GOGCCFLAGS
+	GOHOSTARCH
+	GOHOSTOS
+	GOINSECURE
+	GOMIPS
+	GOMIPS64
+	GOMODCACHE
+	GONOPROXY
+	GONOSUMDB
+	GOOS
+	GOPATH
+	GOPPC64
+	GOPRIVATE
+	GOPROXY
+	GOROOT
+	GOSUMDB
+	GOTMPDIR
+	GOTOOLDIR
+	GOWASM
+	GO_EXTLINK_ENABLED
+	PKG_CONFIG
+`
--- a/tempfork/x509/cert_pool.go
+++ b/tempfork/x509/cert_pool.go
@ -0,0 +1,159 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package x509
+
+import (
+	"encoding/pem"
+	"errors"
+	"runtime"
+)
+
+// CertPool is a set of certificates.
+type CertPool struct {
+	bySubjectKeyId map[string][]int
+	byName         map[string][]int
+	certs          []*Certificate
+}
+
+// NewCertPool returns a new, empty CertPool.
+func NewCertPool() *CertPool {
+	return &CertPool{
+		bySubjectKeyId: make(map[string][]int),
+		byName:         make(map[string][]int),
+	}
+}
+
+func (s *CertPool) copy() *CertPool {
+	p := &CertPool{
+		bySubjectKeyId: make(map[string][]int, len(s.bySubjectKeyId)),
+		byName:         make(map[string][]int, len(s.byName)),
+		certs:          make([]*Certificate, len(s.certs)),
+	}
+	for k, v := range s.bySubjectKeyId {
+		indexes := make([]int, len(v))
+		copy(indexes, v)
+		p.bySubjectKeyId[k] = indexes
+	}
+	for k, v := range s.byName {
+		indexes := make([]int, len(v))
+		copy(indexes, v)
+		p.byName[k] = indexes
+	}
+	copy(p.certs, s.certs)
+	return p
+}
+
+// SystemCertPool returns a copy of the system cert pool.
+//
+// Any mutations to the returned pool are not written to disk and do
+// not affect any other pool returned by SystemCertPool.
+//
+// New changes in the system cert pool might not be reflected
+// in subsequent calls.
+func SystemCertPool() (*CertPool, error) {
+	if runtime.GOOS == "windows" {
+		// Issue 16736, 18609:
+		return nil, errors.New("crypto/x509: system root pool is not available on Windows")
+	}
+
+	if sysRoots := systemRootsPool(); sysRoots != nil {
+		return sysRoots.copy(), nil
+	}
+
+	return loadSystemRoots()
+}
+
+// findPotentialParents returns the indexes of certificates in s which might
+// have signed cert. The caller must not modify the returned slice.
+func (s *CertPool) findPotentialParents(cert *Certificate) []int {
+	if s == nil {
+		return nil
+	}
+
+	var candidates []int
+	if len(cert.AuthorityKeyId) > 0 {
+		candidates = s.bySubjectKeyId[string(cert.AuthorityKeyId)]
+	}
+	if len(candidates) == 0 {
+		candidates = s.byName[string(cert.RawIssuer)]
+	}
+	return candidates
+}
+
+func (s *CertPool) contains(cert *Certificate) bool {
+	if s == nil {
+		return false
+	}
+
+	candidates := s.byName[string(cert.RawSubject)]
+	for _, c := range candidates {
+		if s.certs[c].Equal(cert) {
+			return true
+		}
+	}
+
+	return false
+}
+
+// AddCert adds a certificate to a pool.
+func (s *CertPool) AddCert(cert *Certificate) {
+	if cert == nil {
+		panic("adding nil Certificate to CertPool")
+	}
+
+	// Check that the certificate isn't being added twice.
+	if s.contains(cert) {
+		return
+	}
+
+	n := len(s.certs)
+	s.certs = append(s.certs, cert)
+
+	if len(cert.SubjectKeyId) > 0 {
+		keyId := string(cert.SubjectKeyId)
+		s.bySubjectKeyId[keyId] = append(s.bySubjectKeyId[keyId], n)
+	}
+	name := string(cert.RawSubject)
+	s.byName[name] = append(s.byName[name], n)
+}
+
+// AppendCertsFromPEM attempts to parse a series of PEM encoded certificates.
+// It appends any certificates found to s and reports whether any certificates
+// were successfully parsed.
+//
+// On many Linux systems, /etc/ssl/cert.pem will contain the system wide set
+// of root CAs in a format suitable for this function.
+func (s *CertPool) AppendCertsFromPEM(pemCerts []byte) (ok bool) {
+	for len(pemCerts) > 0 {
+		var block *pem.Block
+		block, pemCerts = pem.Decode(pemCerts)
+		if block == nil {
+			break
+		}
+		if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
+			continue
+		}
+
+		cert, err := ParseCertificate(block.Bytes)
+		if err != nil {
+			continue
+		}
+
+		s.AddCert(cert)
+		ok = true
+	}
+
+	return
+}
+
+// Subjects returns a list of the DER-encoded subjects of
+// all of the certificates in the pool.
+func (s *CertPool) Subjects() [][]byte {
+	res := make([][]byte, len(s.certs))
+	for i, c := range s.certs {
+		res[i] = c.RawSubject
+	}
+	return res
+}
--- a/tempfork/x509/example_test.go
+++ b/tempfork/x509/example_test.go
@ -0,0 +1,137 @@
+// 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 x509_test
+
+import (
+	"crypto/dsa"
+	"crypto/ecdsa"
+	"crypto/ed25519"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/pem"
+	"fmt"
+)
+
+func ExampleCertificate_Verify() {
+	// Verifying with a custom list of root certificates.
+
+	const rootPEM = `
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----`
+
+	const certPEM = `
+-----BEGIN CERTIFICATE-----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==
+-----END CERTIFICATE-----`
+
+	// First, create the set of root certificates. For this example we only
+	// have one. It's also possible to omit this in order to use the
+	// default root set of the current operating system.
+	roots := x509.NewCertPool()
+	ok := roots.AppendCertsFromPEM([]byte(rootPEM))
+	if !ok {
+		panic("failed to parse root certificate")
+	}
+
+	block, _ := pem.Decode([]byte(certPEM))
+	if block == nil {
+		panic("failed to parse certificate PEM")
+	}
+	cert, err := x509.ParseCertificate(block.Bytes)
+	if err != nil {
+		panic("failed to parse certificate: " + err.Error())
+	}
+
+	opts := x509.VerifyOptions{
+		DNSName: "mail.google.com",
+		Roots:   roots,
+	}
+
+	if _, err := cert.Verify(opts); err != nil {
+		panic("failed to verify certificate: " + err.Error())
+	}
+}
+
+func ExampleParsePKIXPublicKey() {
+	const pubPEM = `
+-----BEGIN PUBLIC KEY-----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+-----END PUBLIC KEY-----`
+
+	block, _ := pem.Decode([]byte(pubPEM))
+	if block == nil {
+		panic("failed to parse PEM block containing the public key")
+	}
+
+	pub, err := x509.ParsePKIXPublicKey(block.Bytes)
+	if err != nil {
+		panic("failed to parse DER encoded public key: " + err.Error())
+	}
+
+	switch pub := pub.(type) {
+	case *rsa.PublicKey:
+		fmt.Println("pub is of type RSA:", pub)
+	case *dsa.PublicKey:
+		fmt.Println("pub is of type DSA:", pub)
+	case *ecdsa.PublicKey:
+		fmt.Println("pub is of type ECDSA:", pub)
+	case ed25519.PublicKey:
+		fmt.Println("pub is of type Ed25519:", pub)
+	default:
+		panic("unknown type of public key")
+	}
+}
--- a/tempfork/x509/name_constraints_test.go
+++ b/tempfork/x509/name_constraints_test.go
--- a/tempfork/x509/pem_decrypt.go
+++ b/tempfork/x509/pem_decrypt.go
@ -0,0 +1,240 @@
+// Copyright 2012 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 x509
+
+// RFC 1423 describes the encryption of PEM blocks. The algorithm used to
+// generate a key from the password was derived by looking at the OpenSSL
+// implementation.
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/des"
+	"crypto/md5"
+	"encoding/hex"
+	"encoding/pem"
+	"errors"
+	"io"
+	"strings"
+)
+
+type PEMCipher int
+
+// Possible values for the EncryptPEMBlock encryption algorithm.
+const (
+	_ PEMCipher = iota
+	PEMCipherDES
+	PEMCipher3DES
+	PEMCipherAES128
+	PEMCipherAES192
+	PEMCipherAES256
+)
+
+// rfc1423Algo holds a method for enciphering a PEM block.
+type rfc1423Algo struct {
+	cipher     PEMCipher
+	name       string
+	cipherFunc func(key []byte) (cipher.Block, error)
+	keySize    int
+	blockSize  int
+}
+
+// rfc1423Algos holds a slice of the possible ways to encrypt a PEM
+// block. The ivSize numbers were taken from the OpenSSL source.
+var rfc1423Algos = []rfc1423Algo{{
+	cipher:     PEMCipherDES,
+	name:       "DES-CBC",
+	cipherFunc: des.NewCipher,
+	keySize:    8,
+	blockSize:  des.BlockSize,
+}, {
+	cipher:     PEMCipher3DES,
+	name:       "DES-EDE3-CBC",
+	cipherFunc: des.NewTripleDESCipher,
+	keySize:    24,
+	blockSize:  des.BlockSize,
+}, {
+	cipher:     PEMCipherAES128,
+	name:       "AES-128-CBC",
+	cipherFunc: aes.NewCipher,
+	keySize:    16,
+	blockSize:  aes.BlockSize,
+}, {
+	cipher:     PEMCipherAES192,
+	name:       "AES-192-CBC",
+	cipherFunc: aes.NewCipher,
+	keySize:    24,
+	blockSize:  aes.BlockSize,
+}, {
+	cipher:     PEMCipherAES256,
+	name:       "AES-256-CBC",
+	cipherFunc: aes.NewCipher,
+	keySize:    32,
+	blockSize:  aes.BlockSize,
+},
+}
+
+// deriveKey uses a key derivation function to stretch the password into a key
+// with the number of bits our cipher requires. This algorithm was derived from
+// the OpenSSL source.
+func (c rfc1423Algo) deriveKey(password, salt []byte) []byte {
+	hash := md5.New()
+	out := make([]byte, c.keySize)
+	var digest []byte
+
+	for i := 0; i < len(out); i += len(digest) {
+		hash.Reset()
+		hash.Write(digest)
+		hash.Write(password)
+		hash.Write(salt)
+		digest = hash.Sum(digest[:0])
+		copy(out[i:], digest)
+	}
+	return out
+}
+
+// IsEncryptedPEMBlock returns if the PEM block is password encrypted.
+func IsEncryptedPEMBlock(b *pem.Block) bool {
+	_, ok := b.Headers["DEK-Info"]
+	return ok
+}
+
+// IncorrectPasswordError is returned when an incorrect password is detected.
+var IncorrectPasswordError = errors.New("x509: decryption password incorrect")
+
+// DecryptPEMBlock takes a password encrypted PEM block and the password used to
+// encrypt it and returns a slice of decrypted DER encoded bytes. It inspects
+// the DEK-Info header to determine the algorithm used for decryption. If no
+// DEK-Info header is present, an error is returned. If an incorrect password
+// is detected an IncorrectPasswordError is returned. Because of deficiencies
+// in the encrypted-PEM format, it's not always possible to detect an incorrect
+// password. In these cases no error will be returned but the decrypted DER
+// bytes will be random noise.
+func DecryptPEMBlock(b *pem.Block, password []byte) ([]byte, error) {
+	dek, ok := b.Headers["DEK-Info"]
+	if !ok {
+		return nil, errors.New("x509: no DEK-Info header in block")
+	}
+
+	idx := strings.Index(dek, ",")
+	if idx == -1 {
+		return nil, errors.New("x509: malformed DEK-Info header")
+	}
+
+	mode, hexIV := dek[:idx], dek[idx+1:]
+	ciph := cipherByName(mode)
+	if ciph == nil {
+		return nil, errors.New("x509: unknown encryption mode")
+	}
+	iv, err := hex.DecodeString(hexIV)
+	if err != nil {
+		return nil, err
+	}
+	if len(iv) != ciph.blockSize {
+		return nil, errors.New("x509: incorrect IV size")
+	}
+
+	// Based on the OpenSSL implementation. The salt is the first 8 bytes
+	// of the initialization vector.
+	key := ciph.deriveKey(password, iv[:8])
+	block, err := ciph.cipherFunc(key)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(b.Bytes)%block.BlockSize() != 0 {
+		return nil, errors.New("x509: encrypted PEM data is not a multiple of the block size")
+	}
+
+	data := make([]byte, len(b.Bytes))
+	dec := cipher.NewCBCDecrypter(block, iv)
+	dec.CryptBlocks(data, b.Bytes)
+
+	// Blocks are padded using a scheme where the last n bytes of padding are all
+	// equal to n. It can pad from 1 to blocksize bytes inclusive. See RFC 1423.
+	// For example:
+	//	[x y z 2 2]
+	//	[x y 7 7 7 7 7 7 7]
+	// If we detect a bad padding, we assume it is an invalid password.
+	dlen := len(data)
+	if dlen == 0 || dlen%ciph.blockSize != 0 {
+		return nil, errors.New("x509: invalid padding")
+	}
+	last := int(data[dlen-1])
+	if dlen < last {
+		return nil, IncorrectPasswordError
+	}
+	if last == 0 || last > ciph.blockSize {
+		return nil, IncorrectPasswordError
+	}
+	for _, val := range data[dlen-last:] {
+		if int(val) != last {
+			return nil, IncorrectPasswordError
+		}
+	}
+	return data[:dlen-last], nil
+}
+
+// EncryptPEMBlock returns a PEM block of the specified type holding the
+// given DER-encoded data encrypted with the specified algorithm and
+// password.
+func EncryptPEMBlock(rand io.Reader, blockType string, data, password []byte, alg PEMCipher) (*pem.Block, error) {
+	ciph := cipherByKey(alg)
+	if ciph == nil {
+		return nil, errors.New("x509: unknown encryption mode")
+	}
+	iv := make([]byte, ciph.blockSize)
+	if _, err := io.ReadFull(rand, iv); err != nil {
+		return nil, errors.New("x509: cannot generate IV: " + err.Error())
+	}
+	// The salt is the first 8 bytes of the initialization vector,
+	// matching the key derivation in DecryptPEMBlock.
+	key := ciph.deriveKey(password, iv[:8])
+	block, err := ciph.cipherFunc(key)
+	if err != nil {
+		return nil, err
+	}
+	enc := cipher.NewCBCEncrypter(block, iv)
+	pad := ciph.blockSize - len(data)%ciph.blockSize
+	encrypted := make([]byte, len(data), len(data)+pad)
+	// We could save this copy by encrypting all the whole blocks in
+	// the data separately, but it doesn't seem worth the additional
+	// code.
+	copy(encrypted, data)
+	// See RFC 1423, Section 1.1.
+	for i := 0; i < pad; i++ {
+		encrypted = append(encrypted, byte(pad))
+	}
+	enc.CryptBlocks(encrypted, encrypted)
+
+	return &pem.Block{
+		Type: blockType,
+		Headers: map[string]string{
+			"Proc-Type": "4,ENCRYPTED",
+			"DEK-Info":  ciph.name + "," + hex.EncodeToString(iv),
+		},
+		Bytes: encrypted,
+	}, nil
+}
+
+func cipherByName(name string) *rfc1423Algo {
+	for i := range rfc1423Algos {
+		alg := &rfc1423Algos[i]
+		if alg.name == name {
+			return alg
+		}
+	}
+	return nil
+}
+
+func cipherByKey(key PEMCipher) *rfc1423Algo {
+	for i := range rfc1423Algos {
+		alg := &rfc1423Algos[i]
+		if alg.cipher == key {
+			return alg
+		}
+	}
+	return nil
+}
--- a/tempfork/x509/pem_decrypt_test.go
+++ b/tempfork/x509/pem_decrypt_test.go
@ -0,0 +1,249 @@
+// Copyright 2012 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 x509
+
+import (
+	"bytes"
+	"crypto/rand"
+	"encoding/base64"
+	"encoding/pem"
+	"strings"
+	"testing"
+)
+
+func TestDecrypt(t *testing.T) {
+	for i, data := range testData {
+		t.Logf("test %v. %v", i, data.kind)
+		block, rest := pem.Decode(data.pemData)
+		if len(rest) > 0 {
+			t.Error("extra data")
+		}
+		der, err := DecryptPEMBlock(block, data.password)
+		if err != nil {
+			t.Error("decrypt failed: ", err)
+			continue
+		}
+		if _, err := ParsePKCS1PrivateKey(der); err != nil {
+			t.Error("invalid private key: ", err)
+		}
+		plainDER, err := base64.StdEncoding.DecodeString(data.plainDER)
+		if err != nil {
+			t.Fatal("cannot decode test DER data: ", err)
+		}
+		if !bytes.Equal(der, plainDER) {
+			t.Error("data mismatch")
+		}
+	}
+}
+
+func TestEncrypt(t *testing.T) {
+	for i, data := range testData {
+		t.Logf("test %v. %v", i, data.kind)
+		plainDER, err := base64.StdEncoding.DecodeString(data.plainDER)
+		if err != nil {
+			t.Fatal("cannot decode test DER data: ", err)
+		}
+		password := []byte("kremvax1")
+		block, err := EncryptPEMBlock(rand.Reader, "RSA PRIVATE KEY", plainDER, password, data.kind)
+		if err != nil {
+			t.Error("encrypt: ", err)
+			continue
+		}
+		if !IsEncryptedPEMBlock(block) {
+			t.Error("PEM block does not appear to be encrypted")
+		}
+		if block.Type != "RSA PRIVATE KEY" {
+			t.Errorf("unexpected block type; got %q want %q", block.Type, "RSA PRIVATE KEY")
+		}
+		if block.Headers["Proc-Type"] != "4,ENCRYPTED" {
+			t.Errorf("block does not have correct Proc-Type header")
+		}
+		der, err := DecryptPEMBlock(block, password)
+		if err != nil {
+			t.Error("decrypt: ", err)
+			continue
+		}
+		if !bytes.Equal(der, plainDER) {
+			t.Errorf("data mismatch")
+		}
+	}
+}
+
+var testData = []struct {
+	kind     PEMCipher
+	password []byte
+	pemData  []byte
+	plainDER string
+}{
+	{
+		kind:     PEMCipherDES,
+		password: []byte("asdf"),
+		pemData: []byte(testingKey(`
+-----BEGIN RSA TESTING KEY-----
+Proc-Type: 4,ENCRYPTED
+DEK-Info: DES-CBC,34F09A4FC8DE22B5
+
+WXxy8kbZdiZvANtKvhmPBLV7eVFj2A5z6oAxvI9KGyhG0ZK0skfnt00C24vfU7m5
+ICXeoqP67lzJ18xCzQfHjDaBNs53DSDT+Iz4e8QUep1xQ30+8QKX2NA2coee3nwc
+6oM1cuvhNUDemBH2i3dKgMVkfaga0zQiiOq6HJyGSncCMSruQ7F9iWEfRbFcxFCx
+qtHb1kirfGKEtgWTF+ynyco6+2gMXNu70L7nJcnxnV/RLFkHt7AUU1yrclxz7eZz
+XOH9VfTjb52q/I8Suozq9coVQwg4tXfIoYUdT//O+mB7zJb9HI9Ps77b9TxDE6Gm
+4C9brwZ3zg2vqXcwwV6QRZMtyll9rOpxkbw6NPlpfBqkc3xS51bbxivbO/Nve4KD
+r12ymjFNF4stXCfJnNqKoZ50BHmEEUDu5Wb0fpVn82XrGw7CYc4iug==
+-----END RSA TESTING KEY-----`)),
+		plainDER: `
+MIIBPAIBAAJBAPASZe+tCPU6p80AjHhDkVsLYa51D35e/YGa8QcZyooeZM8EHozo
+KD0fNiKI+53bHdy07N+81VQ8/ejPcRoXPlsCAwEAAQJBAMTxIuSq27VpR+zZ7WJf
+c6fvv1OBvpMZ0/d1pxL/KnOAgq2rD5hDtk9b0LGhTPgQAmrrMTKuSeGoIuYE+gKQ
+QvkCIQD+GC1m+/do+QRurr0uo46Kx1LzLeSCrjBk34wiOp2+dwIhAPHfTLRXS2fv
+7rljm0bYa4+eDZpz+E8RcXEgzhhvcQQ9AiAI5eHZJGOyml3MXnQjiPi55WcDOw0w
+glcRgT6QCEtz2wIhANSyqaFtosIkHKqrDUGfz/bb5tqMYTAnBruVPaf/WEOBAiEA
+9xORWeRG1tRpso4+dYy4KdDkuLPIO01KY6neYGm3BCM=`,
+	},
+	{
+		kind:     PEMCipher3DES,
+		password: []byte("asdf"),
+		pemData: []byte(testingKey(`
+-----BEGIN RSA TESTING KEY-----
+Proc-Type: 4,ENCRYPTED
+DEK-Info: DES-EDE3-CBC,C1F4A6A03682C2C7
+
+0JqVdBEH6iqM7drTkj+e2W/bE3LqakaiWhb9WUVonFkhyu8ca/QzebY3b5gCvAZQ
+YwBvDcT/GHospKqPx+cxDHJNsUASDZws6bz8ZXWJGwZGExKzr0+Qx5fgXn44Ms3x
+8g1ENFuTXtxo+KoNK0zuAMAqp66Llcds3Fjl4XR18QaD0CrVNAfOdgATWZm5GJxk
+Fgx5f84nT+/ovvreG+xeOzWgvtKo0UUZVrhGOgfKLpa57adumcJ6SkUuBtEFpZFB
+ldw5w7WC7d13x2LsRkwo8ZrDKgIV+Y9GNvhuCCkTzNP0V3gNeJpd201HZHR+9n3w
+3z0VjR/MGqsfcy1ziEWMNOO53At3zlG6zP05aHMnMcZoVXadEK6L1gz++inSSDCq
+gI0UJP4e3JVB7AkgYymYAwiYALAkoEIuanxoc50njJk=
+-----END RSA TESTING KEY-----`)),
+		plainDER: `
+MIIBOwIBAAJBANOCXKdoNS/iP/MAbl9cf1/SF3P+Ns7ZeNL27CfmDh0O6Zduaax5
+NBiumd2PmjkaCu7lQ5JOibHfWn+xJsc3kw0CAwEAAQJANX/W8d1Q/sCqzkuAn4xl
+B5a7qfJWaLHndu1QRLNTRJPn0Ee7OKJ4H0QKOhQM6vpjRrz+P2u9thn6wUxoPsef
+QQIhAP/jCkfejFcy4v15beqKzwz08/tslVjF+Yq41eJGejmxAiEA05pMoqfkyjcx
+fyvGhpoOyoCp71vSGUfR2I9CR65oKh0CIC1Msjs66LlfJtQctRq6bCEtFCxEcsP+
+eEjYo/Sk6WphAiEAxpgWPMJeU/shFT28gS+tmhjPZLpEoT1qkVlC14u0b3ECIQDX
+tZZZxCtPAm7shftEib0VU77Lk8MsXJcx2C4voRsjEw==`,
+	},
+	{
+		kind:     PEMCipherAES128,
+		password: []byte("asdf"),
+		pemData: []byte(testingKey(`
+-----BEGIN RSA TESTING KEY-----
+Proc-Type: 4,ENCRYPTED
+DEK-Info: AES-128-CBC,D4492E793FC835CC038A728ED174F78A
+
+EyfQSzXSjv6BaNH+NHdXRlkHdimpF9izWlugVJAPApgXrq5YldPe2aGIOFXyJ+QE
+ZIG20DYqaPzJRjTEbPNZ6Es0S2JJ5yCpKxwJuDkgJZKtF39Q2i36JeGbSZQIuWJE
+GZbBpf1jDH/pr0iGonuAdl2PCCZUiy+8eLsD2tyviHUkFLOB+ykYoJ5t8ngZ/B6D
+33U43LLb7+9zD4y3Q9OVHqBFGyHcxCY9+9Qh4ZnFp7DTf6RY5TNEvE3s4g6aDpBs
+3NbvRVvYTgs8K9EPk4K+5R+P2kD8J8KvEIGxVa1vz8QoCJ/jr7Ka2rvNgPCex5/E
+080LzLHPCrXKdlr/f50yhNWq08ZxMWQFkui+FDHPDUaEELKAXV8/5PDxw80Rtybo
+AVYoCVIbZXZCuCO81op8UcOgEpTtyU5Lgh3Mw5scQL0=
+-----END RSA TESTING KEY-----`)),
+		plainDER: `
+MIIBOgIBAAJBAMBlj5FxYtqbcy8wY89d/S7n0+r5MzD9F63BA/Lpl78vQKtdJ5dT
+cDGh/rBt1ufRrNp0WihcmZi7Mpl/3jHjiWECAwEAAQJABNOHYnKhtDIqFYj1OAJ3
+k3GlU0OlERmIOoeY/cL2V4lgwllPBEs7r134AY4wMmZSBUj8UR/O4SNO668ElKPE
+cQIhAOuqY7/115x5KCdGDMWi+jNaMxIvI4ETGwV40ykGzqlzAiEA0P9oEC3m9tHB
+kbpjSTxaNkrXxDgdEOZz8X0uOUUwHNsCIAwzcSCiGLyYJTULUmP1ESERfW1mlV78
+XzzESaJpIM/zAiBQkSTcl9VhcJreQqvjn5BnPZLP4ZHS4gPwJAGdsj5J4QIhAOVR
+B3WlRNTXR2WsJ5JdByezg9xzdXzULqmga0OE339a`,
+	},
+	{
+		kind:     PEMCipherAES192,
+		password: []byte("asdf"),
+		pemData: []byte(testingKey(`
+-----BEGIN RSA TESTING KEY-----
+Proc-Type: 4,ENCRYPTED
+DEK-Info: AES-192-CBC,E2C9FB02BCA23ADE1829F8D8BC5F5369
+
+cqVslvHqDDM6qwU6YjezCRifXmKsrgEev7ng6Qs7UmDJOpHDgJQZI9fwMFUhIyn5
+FbCu1SHkLMW52Ld3CuEqMnzWMlhPrW8tFvUOrMWPYSisv7nNq88HobZEJcUNL2MM
+Y15XmHW6IJwPqhKyLHpWXyOCVEh4ODND2nV15PCoi18oTa475baxSk7+1qH7GuIs
+Rb7tshNTMqHbCpyo9Rn3UxeFIf9efdl8YLiMoIqc7J8E5e9VlbeQSdLMQOgDAQJG
+ReUtTw8exmKsY4gsSjhkg5uiw7/ZB1Ihto0qnfQJgjGc680qGkT1d6JfvOfeYAk6
+xn5RqS/h8rYAYm64KnepfC9vIujo4NqpaREDmaLdX5MJPQ+SlytITQvgUsUq3q/t
+Ss85xjQEZH3hzwjQqdJvmA4hYP6SUjxYpBM+02xZ1Xw=
+-----END RSA TESTING KEY-----`)),
+		plainDER: `
+MIIBOwIBAAJBAMGcRrZiNNmtF20zyS6MQ7pdGx17aFDl+lTl+qnLuJRUCMUG05xs
+OmxmL/O1Qlf+bnqR8Bgg65SfKg21SYuLhiMCAwEAAQJBAL94uuHyO4wux2VC+qpj
+IzPykjdU7XRcDHbbvksf4xokSeUFjjD3PB0Qa83M94y89ZfdILIqS9x5EgSB4/lX
+qNkCIQD6cCIqLfzq/lYbZbQgAAjpBXeQVYsbvVtJrPrXJAlVVQIhAMXpDKMeFPMn
+J0g2rbx1gngx0qOa5r5iMU5w/noN4W2XAiBjf+WzCG5yFvazD+dOx3TC0A8+4x3P
+uZ3pWbaXf5PNuQIgAcdXarvhelH2w2piY1g3BPeFqhzBSCK/yLGxR82KIh8CIQDD
+qGKsd09NhQ/G27y/DARzOYtml1NvdmCQAgsDIIOLA==`,
+	},
+	{
+		kind:     PEMCipherAES256,
+		password: []byte("asdf"),
+		pemData: []byte(testingKey(`
+-----BEGIN RSA TESTING KEY-----
+Proc-Type: 4,ENCRYPTED
+DEK-Info: AES-256-CBC,8E7ED5CD731902CE938957A886A5FFBD
+
+4Mxr+KIzRVwoOP0wwq6caSkvW0iS+GE2h2Ov/u+n9ZTMwL83PRnmjfjzBgfRZLVf
+JFPXxUK26kMNpIdssNnqGOds+DhB+oSrsNKoxgxSl5OBoYv9eJTVYm7qOyAFIsjr
+DRKAcjYCmzfesr7PVTowwy0RtHmYwyXMGDlAzzZrEvaiySFFmMyKKvtoavwaFoc7
+Pz3RZScwIuubzTGJ1x8EzdffYOsdCa9Mtgpp3L136+23dOd6L/qK2EG2fzrJSHs/
+2XugkleBFSMKzEp9mxXKRfa++uidQvMZTFLDK9w5YjrRvMBo/l2BoZIsq0jAIE1N
+sv5Z/KwlX+3MDEpPQpUwGPlGGdLnjI3UZ+cjgqBcoMiNc6HfgbBgYJSU6aDSHuCk
+clCwByxWkBNgJ2GrkwNrF26v+bGJJJNR4SKouY1jQf0=
+-----END RSA TESTING KEY-----`)),
+		plainDER: `
+MIIBOgIBAAJBAKy3GFkstoCHIEeUU/qO8207m8WSrjksR+p9B4tf1w5k+2O1V/GY
+AQ5WFCApItcOkQe/I0yZZJk/PmCqMzSxrc8CAwEAAQJAOCAz0F7AW9oNelVQSP8F
+Sfzx7O1yom+qWyAQQJF/gFR11gpf9xpVnnyu1WxIRnDUh1LZwUsjwlDYb7MB74id
+oQIhANPcOiLwOPT4sIUpRM5HG6BF1BI7L77VpyGVk8xNP7X/AiEA0LMHZtk4I+lJ
+nClgYp4Yh2JZ1Znbu7IoQMCEJCjwKDECIGd8Dzm5tViTkUW6Hs3Tlf73nNs65duF
+aRnSglss8I3pAiEAonEnKruawgD8RavDFR+fUgmQiPz4FnGGeVgfwpGG1JECIBYq
+PXHYtPqxQIbD2pScR5qum7iGUh11lEUPkmt+2uqS`,
+	},
+	{
+		// generated with:
+		// openssl genrsa -aes128 -passout pass:asdf -out server.orig.key 128
+		kind:     PEMCipherAES128,
+		password: []byte("asdf"),
+		pemData: []byte(testingKey(`
+-----BEGIN RSA TESTING KEY-----
+Proc-Type: 4,ENCRYPTED
+DEK-Info: AES-128-CBC,74611ABC2571AF11B1BF9B69E62C89E7
+
+6ei/MlytjE0FFgZOGQ+jrwomKfpl8kdefeE0NSt/DMRrw8OacHAzBNi3pPEa0eX3
+eND9l7C9meCirWovjj9QWVHrXyugFuDIqgdhQ8iHTgCfF3lrmcttVrbIfMDw+smD
+hTP8O1mS/MHl92NE0nhv0w==
+-----END RSA TESTING KEY-----`)),
+		plainDER: `
+MGMCAQACEQC6ssxmYuauuHGOCDAI54RdAgMBAAECEQCWIn6Yv2O+kBcDF7STctKB
+AgkA8SEfu/2i3g0CCQDGNlXbBHX7kQIIK3Ww5o0cYbECCQDCimPb0dYGsQIIeQ7A
+jryIst8=`,
+	},
+}
+
+var incompleteBlockPEM = testingKey(`
+-----BEGIN RSA TESTING KEY-----
+Proc-Type: 4,ENCRYPTED
+DEK-Info: AES-128-CBC,74611ABC2571AF11B1BF9B69E62C89E7
+
+6L8yXK2MTQUWBk4ZD6OvCiYp+mXyR1594TQ1K38MxGvDw5pwcDME2Lek8RrR5fd40P2XsL2Z4KKt
+ai+OP1BZUetfK6AW4MiqB2FDyIdOAJ8XeWuZy21Wtsh8wPD6yYOFM/w7WZL8weX3Y0TSeG/T
+-----END RSA TESTING KEY-----`)
+
+func TestIncompleteBlock(t *testing.T) {
+	// incompleteBlockPEM contains ciphertext that is not a multiple of the
+	// block size. This previously panicked. See #11215.
+	block, _ := pem.Decode([]byte(incompleteBlockPEM))
+	_, err := DecryptPEMBlock(block, []byte("foo"))
+	if err == nil {
+		t.Fatal("Bad PEM data decrypted successfully")
+	}
+	const expectedSubstr = "block size"
+	if e := err.Error(); !strings.Contains(e, expectedSubstr) {
+		t.Fatalf("Expected error containing %q but got: %q", expectedSubstr, e)
+	}
+}
+
+func testingKey(s string) string { return strings.ReplaceAll(s, "TESTING KEY", "PRIVATE KEY") }
--- a/tempfork/x509/pkcs1.go
+++ b/tempfork/x509/pkcs1.go
@ -0,0 +1,173 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package x509
+
+import (
+	"crypto/rsa"
+	"encoding/asn1"
+	"errors"
+	"math/big"
+)
+
+// pkcs1PrivateKey is a structure which mirrors the PKCS#1 ASN.1 for an RSA private key.
+type pkcs1PrivateKey struct {
+	Version int
+	N       *big.Int
+	E       int
+	D       *big.Int
+	P       *big.Int
+	Q       *big.Int
+	// We ignore these values, if present, because rsa will calculate them.
+	Dp   *big.Int `asn1:"optional"`
+	Dq   *big.Int `asn1:"optional"`
+	Qinv *big.Int `asn1:"optional"`
+
+	AdditionalPrimes []pkcs1AdditionalRSAPrime `asn1:"optional,omitempty"`
+}
+
+type pkcs1AdditionalRSAPrime struct {
+	Prime *big.Int
+
+	// We ignore these values because rsa will calculate them.
+	Exp   *big.Int
+	Coeff *big.Int
+}
+
+// pkcs1PublicKey reflects the ASN.1 structure of a PKCS#1 public key.
+type pkcs1PublicKey struct {
+	N *big.Int
+	E int
+}
+
+// ParsePKCS1PrivateKey parses an RSA private key in PKCS#1, ASN.1 DER form.
+//
+// This kind of key is commonly encoded in PEM blocks of type "RSA PRIVATE KEY".
+func ParsePKCS1PrivateKey(der []byte) (*rsa.PrivateKey, error) {
+	var priv pkcs1PrivateKey
+	rest, err := asn1.Unmarshal(der, &priv)
+	if len(rest) > 0 {
+		return nil, asn1.SyntaxError{Msg: "trailing data"}
+	}
+	if err != nil {
+		if _, err := asn1.Unmarshal(der, &ecPrivateKey{}); err == nil {
+			return nil, errors.New("x509: failed to parse private key (use ParseECPrivateKey instead for this key format)")
+		}
+		if _, err := asn1.Unmarshal(der, &pkcs8{}); err == nil {
+			return nil, errors.New("x509: failed to parse private key (use ParsePKCS8PrivateKey instead for this key format)")
+		}
+		return nil, err
+	}
+
+	if priv.Version > 1 {
+		return nil, errors.New("x509: unsupported private key version")
+	}
+
+	if priv.N.Sign() <= 0 || priv.D.Sign() <= 0 || priv.P.Sign() <= 0 || priv.Q.Sign() <= 0 {
+		return nil, errors.New("x509: private key contains zero or negative value")
+	}
+
+	key := new(rsa.PrivateKey)
+	key.PublicKey = rsa.PublicKey{
+		E: priv.E,
+		N: priv.N,
+	}
+
+	key.D = priv.D
+	key.Primes = make([]*big.Int, 2+len(priv.AdditionalPrimes))
+	key.Primes[0] = priv.P
+	key.Primes[1] = priv.Q
+	for i, a := range priv.AdditionalPrimes {
+		if a.Prime.Sign() <= 0 {
+			return nil, errors.New("x509: private key contains zero or negative prime")
+		}
+		key.Primes[i+2] = a.Prime
+		// We ignore the other two values because rsa will calculate
+		// them as needed.
+	}
+
+	err = key.Validate()
+	if err != nil {
+		return nil, err
+	}
+	key.Precompute()
+
+	return key, nil
+}
+
+// MarshalPKCS1PrivateKey converts an RSA private key to PKCS#1, ASN.1 DER form.
+//
+// This kind of key is commonly encoded in PEM blocks of type "RSA PRIVATE KEY".
+// For a more flexible key format which is not RSA specific, use
+// MarshalPKCS8PrivateKey.
+func MarshalPKCS1PrivateKey(key *rsa.PrivateKey) []byte {
+	key.Precompute()
+
+	version := 0
+	if len(key.Primes) > 2 {
+		version = 1
+	}
+
+	priv := pkcs1PrivateKey{
+		Version: version,
+		N:       key.N,
+		E:       key.PublicKey.E,
+		D:       key.D,
+		P:       key.Primes[0],
+		Q:       key.Primes[1],
+		Dp:      key.Precomputed.Dp,
+		Dq:      key.Precomputed.Dq,
+		Qinv:    key.Precomputed.Qinv,
+	}
+
+	priv.AdditionalPrimes = make([]pkcs1AdditionalRSAPrime, len(key.Precomputed.CRTValues))
+	for i, values := range key.Precomputed.CRTValues {
+		priv.AdditionalPrimes[i].Prime = key.Primes[2+i]
+		priv.AdditionalPrimes[i].Exp = values.Exp
+		priv.AdditionalPrimes[i].Coeff = values.Coeff
+	}
+
+	b, _ := asn1.Marshal(priv)
+	return b
+}
+
+// ParsePKCS1PublicKey parses an RSA public key in PKCS#1, ASN.1 DER form.
+//
+// This kind of key is commonly encoded in PEM blocks of type "RSA PUBLIC KEY".
+func ParsePKCS1PublicKey(der []byte) (*rsa.PublicKey, error) {
+	var pub pkcs1PublicKey
+	rest, err := asn1.Unmarshal(der, &pub)
+	if err != nil {
+		if _, err := asn1.Unmarshal(der, &publicKeyInfo{}); err == nil {
+			return nil, errors.New("x509: failed to parse public key (use ParsePKIXPublicKey instead for this key format)")
+		}
+		return nil, err
+	}
+	if len(rest) > 0 {
+		return nil, asn1.SyntaxError{Msg: "trailing data"}
+	}
+
+	if pub.N.Sign() <= 0 || pub.E <= 0 {
+		return nil, errors.New("x509: public key contains zero or negative value")
+	}
+	if pub.E > 1<<31-1 {
+		return nil, errors.New("x509: public key contains large public exponent")
+	}
+
+	return &rsa.PublicKey{
+		E: pub.E,
+		N: pub.N,
+	}, nil
+}
+
+// MarshalPKCS1PublicKey converts an RSA public key to PKCS#1, ASN.1 DER form.
+//
+// This kind of key is commonly encoded in PEM blocks of type "RSA PUBLIC KEY".
+func MarshalPKCS1PublicKey(key *rsa.PublicKey) []byte {
+	derBytes, _ := asn1.Marshal(pkcs1PublicKey{
+		N: key.N,
+		E: key.E,
+	})
+	return derBytes
+}
--- a/tempfork/x509/pkcs8.go
+++ b/tempfork/x509/pkcs8.go
@ -0,0 +1,136 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package x509
+
+import (
+	"crypto/ecdsa"
+	"crypto/ed25519"
+	"crypto/rsa"
+	"crypto/x509/pkix"
+	"encoding/asn1"
+	"errors"
+	"fmt"
+)
+
+// pkcs8 reflects an ASN.1, PKCS#8 PrivateKey. See
+// ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-8/pkcs-8v1_2.asn
+// and RFC 5208.
+type pkcs8 struct {
+	Version    int
+	Algo       pkix.AlgorithmIdentifier
+	PrivateKey []byte
+	// optional attributes omitted.
+}
+
+// ParsePKCS8PrivateKey parses an unencrypted private key in PKCS#8, ASN.1 DER form.
+//
+// It returns a *rsa.PrivateKey, a *ecdsa.PrivateKey, or a ed25519.PrivateKey.
+// More types might be supported in the future.
+//
+// This kind of key is commonly encoded in PEM blocks of type "PRIVATE KEY".
+func ParsePKCS8PrivateKey(der []byte) (key interface{}, err error) {
+	var privKey pkcs8
+	if _, err := asn1.Unmarshal(der, &privKey); err != nil {
+		if _, err := asn1.Unmarshal(der, &ecPrivateKey{}); err == nil {
+			return nil, errors.New("x509: failed to parse private key (use ParseECPrivateKey instead for this key format)")
+		}
+		if _, err := asn1.Unmarshal(der, &pkcs1PrivateKey{}); err == nil {
+			return nil, errors.New("x509: failed to parse private key (use ParsePKCS1PrivateKey instead for this key format)")
+		}
+		return nil, err
+	}
+	switch {
+	case privKey.Algo.Algorithm.Equal(oidPublicKeyRSA):
+		key, err = ParsePKCS1PrivateKey(privKey.PrivateKey)
+		if err != nil {
+			return nil, errors.New("x509: failed to parse RSA private key embedded in PKCS#8: " + err.Error())
+		}
+		return key, nil
+
+	case privKey.Algo.Algorithm.Equal(oidPublicKeyECDSA):
+		bytes := privKey.Algo.Parameters.FullBytes
+		namedCurveOID := new(asn1.ObjectIdentifier)
+		if _, err := asn1.Unmarshal(bytes, namedCurveOID); err != nil {
+			namedCurveOID = nil
+		}
+		key, err = parseECPrivateKey(namedCurveOID, privKey.PrivateKey)
+		if err != nil {
+			return nil, errors.New("x509: failed to parse EC private key embedded in PKCS#8: " + err.Error())
+		}
+		return key, nil
+
+	case privKey.Algo.Algorithm.Equal(oidPublicKeyEd25519):
+		if l := len(privKey.Algo.Parameters.FullBytes); l != 0 {
+			return nil, errors.New("x509: invalid Ed25519 private key parameters")
+		}
+		var curvePrivateKey []byte
+		if _, err := asn1.Unmarshal(privKey.PrivateKey, &curvePrivateKey); err != nil {
+			return nil, fmt.Errorf("x509: invalid Ed25519 private key: %v", err)
+		}
+		if l := len(curvePrivateKey); l != ed25519.SeedSize {
+			return nil, fmt.Errorf("x509: invalid Ed25519 private key length: %d", l)
+		}
+		return ed25519.NewKeyFromSeed(curvePrivateKey), nil
+
+	default:
+		return nil, fmt.Errorf("x509: PKCS#8 wrapping contained private key with unknown algorithm: %v", privKey.Algo.Algorithm)
+	}
+}
+
+// MarshalPKCS8PrivateKey converts a private key to PKCS#8, ASN.1 DER form.
+//
+// The following key types are currently supported: *rsa.PrivateKey, *ecdsa.PrivateKey
+// and ed25519.PrivateKey. Unsupported key types result in an error.
+//
+// This kind of key is commonly encoded in PEM blocks of type "PRIVATE KEY".
+func MarshalPKCS8PrivateKey(key interface{}) ([]byte, error) {
+	var privKey pkcs8
+
+	switch k := key.(type) {
+	case *rsa.PrivateKey:
+		privKey.Algo = pkix.AlgorithmIdentifier{
+			Algorithm:  oidPublicKeyRSA,
+			Parameters: asn1.NullRawValue,
+		}
+		privKey.PrivateKey = MarshalPKCS1PrivateKey(k)
+
+	case *ecdsa.PrivateKey:
+		oid, ok := oidFromNamedCurve(k.Curve)
+		if !ok {
+			return nil, errors.New("x509: unknown curve while marshaling to PKCS#8")
+		}
+
+		oidBytes, err := asn1.Marshal(oid)
+		if err != nil {
+			return nil, errors.New("x509: failed to marshal curve OID: " + err.Error())
+		}
+
+		privKey.Algo = pkix.AlgorithmIdentifier{
+			Algorithm: oidPublicKeyECDSA,
+			Parameters: asn1.RawValue{
+				FullBytes: oidBytes,
+			},
+		}
+
+		if privKey.PrivateKey, err = marshalECPrivateKeyWithOID(k, nil); err != nil {
+			return nil, errors.New("x509: failed to marshal EC private key while building PKCS#8: " + err.Error())
+		}
+
+	case ed25519.PrivateKey:
+		privKey.Algo = pkix.AlgorithmIdentifier{
+			Algorithm: oidPublicKeyEd25519,
+		}
+		curvePrivateKey, err := asn1.Marshal(k.Seed())
+		if err != nil {
+			return nil, fmt.Errorf("x509: failed to marshal private key: %v", err)
+		}
+		privKey.PrivateKey = curvePrivateKey
+
+	default:
+		return nil, fmt.Errorf("x509: unknown key type while marshaling PKCS#8: %T", key)
+	}
+
+	return asn1.Marshal(privKey)
+}
--- a/tempfork/x509/pkcs8_test.go
+++ b/tempfork/x509/pkcs8_test.go
@ -0,0 +1,140 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package x509
+
+import (
+	"bytes"
+	"crypto/ecdsa"
+	"crypto/ed25519"
+	"crypto/elliptic"
+	"crypto/rsa"
+	"encoding/hex"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+// Generated using:
+//   openssl genrsa 1024 | openssl pkcs8 -topk8 -nocrypt
+var pkcs8RSAPrivateKeyHex = `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`
+
+// Generated using:
+//   openssl ecparam -genkey -name secp224r1 | openssl pkcs8 -topk8 -nocrypt
+var pkcs8P224PrivateKeyHex = `3078020100301006072a8648ce3d020106052b810400210461305f020101041cca3d72b3e88fed2684576dad9b80a9180363a5424986900e3abcab3fa13c033a0004f8f2a6372872a4e61263ed893afb919576a4cacfecd6c081a2cbc76873cf4ba8530703c6042b3a00e2205087e87d2435d2e339e25702fae1`
+
+// Generated using:
+//   openssl ecparam -genkey -name secp256r1 | openssl pkcs8 -topk8 -nocrypt
+var pkcs8P256PrivateKeyHex = `308187020100301306072a8648ce3d020106082a8648ce3d030107046d306b0201010420dad6b2f49ca774c36d8ae9517e935226f667c929498f0343d2424d0b9b591b43a14403420004b9c9b90095476afe7b860d8bd43568cab7bcb2eed7b8bf2fa0ce1762dd20b04193f859d2d782b1e4cbfd48492f1f533113a6804903f292258513837f07fda735`
+
+// Generated using:
+//   openssl ecparam -genkey -name secp384r1 | openssl pkcs8 -topk8 -nocrypt
+var pkcs8P384PrivateKeyHex = `3081b6020100301006072a8648ce3d020106052b8104002204819e30819b02010104309bf832f6aaaeacb78ce47ffb15e6fd0fd48683ae79df6eca39bfb8e33829ac94aa29d08911568684c2264a08a4ceb679a164036200049070ad4ed993c7770d700e9f6dc2baa83f63dd165b5507f98e8ff29b5d2e78ccbe05c8ddc955dbf0f7497e8222cfa49314fe4e269459f8e880147f70d785e530f2939e4bf9f838325bb1a80ad4cf59272ae0e5efe9a9dc33d874492596304bd3`
+
+// Generated using:
+//   openssl ecparam -genkey -name secp521r1 | openssl pkcs8 -topk8 -nocrypt
+//
+// Note that OpenSSL will truncate the private key if it can (i.e. it emits it
+// like an integer, even though it's an OCTET STRING field). Thus if you
+// regenerate this you may, randomly, find that it's a byte shorter than
+// expected and the Go test will fail to recreate it exactly.
+var pkcs8P521PrivateKeyHex = `3081ee020100301006072a8648ce3d020106052b810400230481d63081d3020101044200cfe0b87113a205cf291bb9a8cd1a74ac6c7b2ebb8199aaa9a5010d8b8012276fa3c22ac913369fa61beec2a3b8b4516bc049bde4fb3b745ac11b56ab23ac52e361a1818903818600040138f75acdd03fbafa4f047a8e4b272ba9d555c667962b76f6f232911a5786a0964e5edea6bd21a6f8725720958de049c6e3e6661c1c91b227cebee916c0319ed6ca003db0a3206d372229baf9dd25d868bf81140a518114803ce40c1855074d68c4e9dab9e65efba7064c703b400f1767f217dac82715ac1f6d88c74baf47a7971de4ea`
+
+// From RFC 8410, Section 7.
+var pkcs8Ed25519PrivateKeyHex = `302e020100300506032b657004220420d4ee72dbf913584ad5b6d8f1f769f8ad3afe7c28cbf1d4fbe097a88f44755842`
+
+func TestPKCS8(t *testing.T) {
+	tests := []struct {
+		name    string
+		keyHex  string
+		keyType reflect.Type
+		curve   elliptic.Curve
+	}{
+		{
+			name:    "RSA private key",
+			keyHex:  pkcs8RSAPrivateKeyHex,
+			keyType: reflect.TypeOf(&rsa.PrivateKey{}),
+		},
+		{
+			name:    "P-224 private key",
+			keyHex:  pkcs8P224PrivateKeyHex,
+			keyType: reflect.TypeOf(&ecdsa.PrivateKey{}),
+			curve:   elliptic.P224(),
+		},
+		{
+			name:    "P-256 private key",
+			keyHex:  pkcs8P256PrivateKeyHex,
+			keyType: reflect.TypeOf(&ecdsa.PrivateKey{}),
+			curve:   elliptic.P256(),
+		},
+		{
+			name:    "P-384 private key",
+			keyHex:  pkcs8P384PrivateKeyHex,
+			keyType: reflect.TypeOf(&ecdsa.PrivateKey{}),
+			curve:   elliptic.P384(),
+		},
+		{
+			name:    "P-521 private key",
+			keyHex:  pkcs8P521PrivateKeyHex,
+			keyType: reflect.TypeOf(&ecdsa.PrivateKey{}),
+			curve:   elliptic.P521(),
+		},
+		{
+			name:    "Ed25519 private key",
+			keyHex:  pkcs8Ed25519PrivateKeyHex,
+			keyType: reflect.TypeOf(ed25519.PrivateKey{}),
+		},
+	}
+
+	for _, test := range tests {
+		derBytes, err := hex.DecodeString(test.keyHex)
+		if err != nil {
+			t.Errorf("%s: failed to decode hex: %s", test.name, err)
+			continue
+		}
+		privKey, err := ParsePKCS8PrivateKey(derBytes)
+		if err != nil {
+			t.Errorf("%s: failed to decode PKCS#8: %s", test.name, err)
+			continue
+		}
+		if reflect.TypeOf(privKey) != test.keyType {
+			t.Errorf("%s: decoded PKCS#8 returned unexpected key type: %T", test.name, privKey)
+			continue
+		}
+		if ecKey, isEC := privKey.(*ecdsa.PrivateKey); isEC && ecKey.Curve != test.curve {
+			t.Errorf("%s: decoded PKCS#8 returned unexpected curve %#v", test.name, ecKey.Curve)
+			continue
+		}
+		reserialised, err := MarshalPKCS8PrivateKey(privKey)
+		if err != nil {
+			t.Errorf("%s: failed to marshal into PKCS#8: %s", test.name, err)
+			continue
+		}
+		if !bytes.Equal(derBytes, reserialised) {
+			t.Errorf("%s: marshaled PKCS#8 didn't match original: got %x, want %x", test.name, reserialised, derBytes)
+			continue
+		}
+	}
+}
+
+const hexPKCS8TestPKCS1Key = "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"
+const hexPKCS8TestECKey = "3081a40201010430bdb9839c08ee793d1157886a7a758a3c8b2a17a4df48f17ace57c72c56b4723cf21dcda21d4e1ad57ff034f19fcfd98ea00706052b81040022a16403620004feea808b5ee2429cfcce13c32160e1c960990bd050bb0fdf7222f3decd0a55008e32a6aa3c9062051c4cba92a7a3b178b24567412d43cdd2f882fa5addddd726fe3e208d2c26d733a773a597abb749714df7256ead5105fa6e7b3650de236b50"
+
+var pkcs8MismatchKeyTests = []struct {
+	hexKey        string
+	errorContains string
+}{
+	{hexKey: hexPKCS8TestECKey, errorContains: "use ParseECPrivateKey instead"},
+	{hexKey: hexPKCS8TestPKCS1Key, errorContains: "use ParsePKCS1PrivateKey instead"},
+}
+
+func TestPKCS8MismatchKeyFormat(t *testing.T) {
+	for i, test := range pkcs8MismatchKeyTests {
+		derBytes, _ := hex.DecodeString(test.hexKey)
+		_, err := ParsePKCS8PrivateKey(derBytes)
+		if !strings.Contains(err.Error(), test.errorContains) {
+			t.Errorf("#%d: expected error containing %q, got %s", i, test.errorContains, err)
+		}
+	}
+}
--- a/tempfork/x509/root.go
+++ b/tempfork/x509/root.go
@ -0,0 +1,25 @@
+// Copyright 2012 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 x509
+
+import "sync"
+
+var (
+	once           sync.Once
+	systemRoots    *CertPool
+	systemRootsErr error
+)
+
+func systemRootsPool() *CertPool {
+	once.Do(initSystemRoots)
+	return systemRoots
+}
+
+func initSystemRoots() {
+	systemRoots, systemRootsErr = loadSystemRoots()
+	if systemRootsErr != nil {
+		systemRoots = nil
+	}
+}
--- a/tempfork/x509/root_aix.go
+++ b/tempfork/x509/root_aix.go
@ -0,0 +1,10 @@
+// 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 x509
+
+// Possible certificate files; stop after finding one.
+var certFiles = []string{
+	"/var/ssl/certs/ca-bundle.crt",
+}
--- a/tempfork/x509/root_bsd.go
+++ b/tempfork/x509/root_bsd.go
@ -0,0 +1,15 @@
+// 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.
+
+// +build dragonfly freebsd netbsd openbsd
+
+package x509
+
+// Possible certificate files; stop after finding one.
+var certFiles = []string{
+	"/usr/local/etc/ssl/cert.pem",            // FreeBSD
+	"/etc/ssl/cert.pem",                      // OpenBSD
+	"/usr/local/share/certs/ca-root-nss.crt", // DragonFly
+	"/etc/openssl/certs/ca-certificates.crt", // NetBSD
+}
--- a/tempfork/x509/root_cgo_darwin.go
+++ b/tempfork/x509/root_cgo_darwin.go
@ -0,0 +1,314 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build cgo,!arm64,!ios
+
+package x509
+
+/*
+#cgo CFLAGS: -mmacosx-version-min=10.11
+#cgo LDFLAGS: -framework CoreFoundation -framework Security
+
+#include <errno.h>
+#include <sys/sysctl.h>
+
+#include <CoreFoundation/CoreFoundation.h>
+#include <Security/Security.h>
+
+static Boolean isSSLPolicy(SecPolicyRef policyRef) {
+	if (!policyRef) {
+		return false;
+	}
+	CFDictionaryRef properties = SecPolicyCopyProperties(policyRef);
+	if (properties == NULL) {
+		return false;
+	}
+	Boolean isSSL = false;
+	CFTypeRef value = NULL;
+	if (CFDictionaryGetValueIfPresent(properties, kSecPolicyOid, (const void **)&value)) {
+		isSSL = CFEqual(value, kSecPolicyAppleSSL);
+	}
+	CFRelease(properties);
+	return isSSL;
+}
+
+// sslTrustSettingsResult obtains the final kSecTrustSettingsResult value
+// for a certificate in the user or admin domain, combining usage constraints
+// for the SSL SecTrustSettingsPolicy, ignoring SecTrustSettingsKeyUsage and
+// kSecTrustSettingsAllowedError.
+// https://developer.apple.com/documentation/security/1400261-sectrustsettingscopytrustsetting
+static SInt32 sslTrustSettingsResult(SecCertificateRef cert) {
+	CFArrayRef trustSettings = NULL;
+	OSStatus err = SecTrustSettingsCopyTrustSettings(cert, kSecTrustSettingsDomainUser, &trustSettings);
+
+	// According to Apple's SecTrustServer.c, "user trust settings overrule admin trust settings",
+	// but the rules of the override are unclear. Let's assume admin trust settings are applicable
+	// if and only if user trust settings fail to load or are NULL.
+	if (err != errSecSuccess || trustSettings == NULL) {
+		if (trustSettings != NULL) CFRelease(trustSettings);
+		err = SecTrustSettingsCopyTrustSettings(cert, kSecTrustSettingsDomainAdmin, &trustSettings);
+	}
+
+	// > no trust settings [...] means "this certificate must be verified to a known trusted certificate”
+	// (Should this cause a fallback from user to admin domain? It's unclear.)
+	if (err != errSecSuccess || trustSettings == NULL) {
+		if (trustSettings != NULL) CFRelease(trustSettings);
+		return kSecTrustSettingsResultUnspecified;
+	}
+
+	// > An empty trust settings array means "always trust this certificate” with an
+	// > overall trust setting for the certificate of kSecTrustSettingsResultTrustRoot.
+	if (CFArrayGetCount(trustSettings) == 0) {
+		CFRelease(trustSettings);
+		return kSecTrustSettingsResultTrustRoot;
+	}
+
+	// kSecTrustSettingsResult is defined as CFSTR("kSecTrustSettingsResult"),
+	// but the Go linker's internal linking mode can't handle CFSTR relocations.
+	// Create our own dynamic string instead and release it below.
+	CFStringRef _kSecTrustSettingsResult = CFStringCreateWithCString(
+		NULL, "kSecTrustSettingsResult", kCFStringEncodingUTF8);
+	CFStringRef _kSecTrustSettingsPolicy = CFStringCreateWithCString(
+		NULL, "kSecTrustSettingsPolicy", kCFStringEncodingUTF8);
+	CFStringRef _kSecTrustSettingsPolicyString = CFStringCreateWithCString(
+		NULL, "kSecTrustSettingsPolicyString", kCFStringEncodingUTF8);
+
+	CFIndex m; SInt32 result = 0;
+	for (m = 0; m < CFArrayGetCount(trustSettings); m++) {
+		CFDictionaryRef tSetting = (CFDictionaryRef)CFArrayGetValueAtIndex(trustSettings, m);
+
+		// First, check if this trust setting is constrained to a non-SSL policy.
+		SecPolicyRef policyRef;
+		if (CFDictionaryGetValueIfPresent(tSetting, _kSecTrustSettingsPolicy, (const void**)&policyRef)) {
+			if (!isSSLPolicy(policyRef)) {
+				continue;
+			}
+		}
+
+		if (CFDictionaryContainsKey(tSetting, _kSecTrustSettingsPolicyString)) {
+			// Restricted to a hostname, not a root.
+			continue;
+		}
+
+		CFNumberRef cfNum;
+		if (CFDictionaryGetValueIfPresent(tSetting, _kSecTrustSettingsResult, (const void**)&cfNum)) {
+			CFNumberGetValue(cfNum, kCFNumberSInt32Type, &result);
+		} else {
+			// > If this key is not present, a default value of
+			// > kSecTrustSettingsResultTrustRoot is assumed.
+			result = kSecTrustSettingsResultTrustRoot;
+		}
+
+		// If multiple dictionaries match, we are supposed to "OR" them,
+		// the semantics of which are not clear. Since TrustRoot and TrustAsRoot
+		// are mutually exclusive, Deny should probably override, and Invalid and
+		// Unspecified be overridden, approximate this by stopping at the first
+		// TrustRoot, TrustAsRoot or Deny.
+		if (result == kSecTrustSettingsResultTrustRoot) {
+			break;
+		} else if (result == kSecTrustSettingsResultTrustAsRoot) {
+			break;
+		} else if (result == kSecTrustSettingsResultDeny) {
+			break;
+		}
+	}
+
+	// If trust settings are present, but none of them match the policy...
+	// the docs don't tell us what to do.
+	//
+	// "Trust settings for a given use apply if any of the dictionaries in the
+	// certificate’s trust settings array satisfies the specified use." suggests
+	// that it's as if there were no trust settings at all, so we should probably
+	// fallback to the admin trust settings. TODO.
+	if (result == 0) {
+		result = kSecTrustSettingsResultUnspecified;
+	}
+
+	CFRelease(_kSecTrustSettingsPolicy);
+	CFRelease(_kSecTrustSettingsPolicyString);
+	CFRelease(_kSecTrustSettingsResult);
+	CFRelease(trustSettings);
+
+	return result;
+}
+
+// isRootCertificate reports whether Subject and Issuer match.
+static Boolean isRootCertificate(SecCertificateRef cert, CFErrorRef *errRef) {
+	CFDataRef subjectName = SecCertificateCopyNormalizedSubjectContent(cert, errRef);
+	if (*errRef != NULL) {
+		return false;
+	}
+	CFDataRef issuerName = SecCertificateCopyNormalizedIssuerContent(cert, errRef);
+	if (*errRef != NULL) {
+		CFRelease(subjectName);
+		return false;
+	}
+	Boolean equal = CFEqual(subjectName, issuerName);
+	CFRelease(subjectName);
+	CFRelease(issuerName);
+	return equal;
+}
+
+// CopyPEMRoots fetches the system's list of trusted X.509 root certificates
+// for the kSecTrustSettingsPolicy SSL.
+//
+// On success it returns 0 and fills pemRoots with a CFDataRef that contains the extracted root
+// certificates of the system. On failure, the function returns -1.
+// Additionally, it fills untrustedPemRoots with certs that must be removed from pemRoots.
+//
+// Note: The CFDataRef returned in pemRoots and untrustedPemRoots must
+// be released (using CFRelease) after we've consumed its content.
+static int CopyPEMRoots(CFDataRef *pemRoots, CFDataRef *untrustedPemRoots, bool debugDarwinRoots) {
+	int i;
+
+	if (debugDarwinRoots) {
+		fprintf(stderr, "crypto/x509: kSecTrustSettingsResultInvalid = %d\n", kSecTrustSettingsResultInvalid);
+		fprintf(stderr, "crypto/x509: kSecTrustSettingsResultTrustRoot = %d\n", kSecTrustSettingsResultTrustRoot);
+		fprintf(stderr, "crypto/x509: kSecTrustSettingsResultTrustAsRoot = %d\n", kSecTrustSettingsResultTrustAsRoot);
+		fprintf(stderr, "crypto/x509: kSecTrustSettingsResultDeny = %d\n", kSecTrustSettingsResultDeny);
+		fprintf(stderr, "crypto/x509: kSecTrustSettingsResultUnspecified = %d\n", kSecTrustSettingsResultUnspecified);
+	}
+
+	// Get certificates from all domains, not just System, this lets
+	// the user add CAs to their "login" keychain, and Admins to add
+	// to the "System" keychain
+	SecTrustSettingsDomain domains[] = { kSecTrustSettingsDomainSystem,
+		kSecTrustSettingsDomainAdmin, kSecTrustSettingsDomainUser };
+
+	int numDomains = sizeof(domains)/sizeof(SecTrustSettingsDomain);
+	if (pemRoots == NULL || untrustedPemRoots == NULL) {
+		return -1;
+	}
+
+	CFMutableDataRef combinedData = CFDataCreateMutable(kCFAllocatorDefault, 0);
+	CFMutableDataRef combinedUntrustedData = CFDataCreateMutable(kCFAllocatorDefault, 0);
+	for (i = 0; i < numDomains; i++) {
+		int j;
+		CFArrayRef certs = NULL;
+		OSStatus err = SecTrustSettingsCopyCertificates(domains[i], &certs);
+		if (err != noErr) {
+			continue;
+		}
+
+		CFIndex numCerts = CFArrayGetCount(certs);
+		for (j = 0; j < numCerts; j++) {
+			SecCertificateRef cert = (SecCertificateRef)CFArrayGetValueAtIndex(certs, j);
+			if (cert == NULL) {
+				continue;
+			}
+
+			SInt32 result;
+			if (domains[i] == kSecTrustSettingsDomainSystem) {
+				// Certs found in the system domain are always trusted. If the user
+				// configures "Never Trust" on such a cert, it will also be found in the
+				// admin or user domain, causing it to be added to untrustedPemRoots. The
+				// Go code will then clean this up.
+				result = kSecTrustSettingsResultTrustRoot;
+			} else {
+				result = sslTrustSettingsResult(cert);
+				if (debugDarwinRoots) {
+					CFErrorRef errRef = NULL;
+					CFStringRef summary = SecCertificateCopyShortDescription(NULL, cert, &errRef);
+					if (errRef != NULL) {
+						fprintf(stderr, "crypto/x509: SecCertificateCopyShortDescription failed\n");
+						CFRelease(errRef);
+						continue;
+					}
+
+					CFIndex length = CFStringGetLength(summary);
+					CFIndex maxSize = CFStringGetMaximumSizeForEncoding(length, kCFStringEncodingUTF8) + 1;
+					char *buffer = malloc(maxSize);
+					if (CFStringGetCString(summary, buffer, maxSize, kCFStringEncodingUTF8)) {
+						fprintf(stderr, "crypto/x509: %s returned %d\n", buffer, (int)result);
+					}
+					free(buffer);
+					CFRelease(summary);
+				}
+			}
+
+			CFMutableDataRef appendTo;
+			// > Note the distinction between the results kSecTrustSettingsResultTrustRoot
+			// > and kSecTrustSettingsResultTrustAsRoot: The former can only be applied to
+			// > root (self-signed) certificates; the latter can only be applied to
+			// > non-root certificates.
+			if (result == kSecTrustSettingsResultTrustRoot) {
+				CFErrorRef errRef = NULL;
+				if (!isRootCertificate(cert, &errRef) || errRef != NULL) {
+					if (errRef != NULL) CFRelease(errRef);
+					continue;
+				}
+
+				appendTo = combinedData;
+			} else if (result == kSecTrustSettingsResultTrustAsRoot) {
+				CFErrorRef errRef = NULL;
+				if (isRootCertificate(cert, &errRef) || errRef != NULL) {
+					if (errRef != NULL) CFRelease(errRef);
+					continue;
+				}
+
+				appendTo = combinedData;
+			} else if (result == kSecTrustSettingsResultDeny) {
+				appendTo = combinedUntrustedData;
+			} else if (result == kSecTrustSettingsResultUnspecified) {
+				// Certificates with unspecified trust should probably be added to a pool of
+				// intermediates for chain building, or checked for transitive trust and
+				// added to the root pool (which is an imprecise approximation because it
+				// cuts chains short) but we don't support either at the moment. TODO.
+				continue;
+			} else {
+				continue;
+			}
+
+			CFDataRef data = NULL;
+			err = SecItemExport(cert, kSecFormatX509Cert, kSecItemPemArmour, NULL, &data);
+			if (err != noErr) {
+				continue;
+			}
+			if (data != NULL) {
+				CFDataAppendBytes(appendTo, CFDataGetBytePtr(data), CFDataGetLength(data));
+				CFRelease(data);
+			}
+		}
+		CFRelease(certs);
+	}
+	*pemRoots = combinedData;
+	*untrustedPemRoots = combinedUntrustedData;
+	return 0;
+}
+*/
+import "C"
+import (
+	"errors"
+	"unsafe"
+)
+
+func loadSystemRoots() (*CertPool, error) {
+	var data, untrustedData C.CFDataRef
+	err := C.CopyPEMRoots(&data, &untrustedData, C.bool(debugDarwinRoots))
+	if err == -1 {
+		return nil, errors.New("crypto/x509: failed to load darwin system roots with cgo")
+	}
+	defer C.CFRelease(C.CFTypeRef(data))
+	defer C.CFRelease(C.CFTypeRef(untrustedData))
+
+	buf := C.GoBytes(unsafe.Pointer(C.CFDataGetBytePtr(data)), C.int(C.CFDataGetLength(data)))
+	roots := NewCertPool()
+	roots.AppendCertsFromPEM(buf)
+
+	if C.CFDataGetLength(untrustedData) == 0 {
+		return roots, nil
+	}
+
+	buf = C.GoBytes(unsafe.Pointer(C.CFDataGetBytePtr(untrustedData)), C.int(C.CFDataGetLength(untrustedData)))
+	untrustedRoots := NewCertPool()
+	untrustedRoots.AppendCertsFromPEM(buf)
+
+	trustedRoots := NewCertPool()
+	for _, c := range roots.certs {
+		if !untrustedRoots.contains(c) {
+			trustedRoots.AddCert(c)
+		}
+	}
+	return trustedRoots, nil
+}
--- a/tempfork/x509/root_darwin.go
+++ b/tempfork/x509/root_darwin.go
@ -0,0 +1,288 @@
+// Copyright 2013 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:generate go run root_darwin_arm_gen.go -output root_darwin_armx.go
+
+package x509
+
+import (
+	"bufio"
+	"bytes"
+	"crypto/sha1"
+	"encoding/pem"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"sync"
+)
+
+var debugDarwinRoots = strings.Contains(os.Getenv("GODEBUG"), "x509roots=1")
+
+func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
+	return nil, nil
+}
+
+// This code is only used when compiling without cgo.
+// It is here, instead of root_nocgo_darwin.go, so that tests can check it
+// even if the tests are run with cgo enabled.
+// The linker will not include these unused functions in binaries built with cgo enabled.
+
+// execSecurityRoots finds the macOS list of trusted root certificates
+// using only command-line tools. This is our fallback path when cgo isn't available.
+//
+// The strategy is as follows:
+//
+// 1. Run "security trust-settings-export" and "security
+//    trust-settings-export -d" to discover the set of certs with some
+//    user-tweaked trust policy. We're too lazy to parse the XML
+//    (Issue 26830) to understand what the trust
+//    policy actually is. We just learn that there is _some_ policy.
+//
+// 2. Run "security find-certificate" to dump the list of system root
+//    CAs in PEM format.
+//
+// 3. For each dumped cert, conditionally verify it with "security
+//    verify-cert" if that cert was in the set discovered in Step 1.
+//    Without the Step 1 optimization, running "security verify-cert"
+//    150-200 times takes 3.5 seconds. With the optimization, the
+//    whole process takes about 180 milliseconds with 1 untrusted root
+//    CA. (Compared to 110ms in the cgo path)
+func execSecurityRoots() (*CertPool, error) {
+	hasPolicy, err := getCertsWithTrustPolicy()
+	if err != nil {
+		return nil, err
+	}
+	if debugDarwinRoots {
+		fmt.Fprintf(os.Stderr, "crypto/x509: %d certs have a trust policy\n", len(hasPolicy))
+	}
+
+	keychains := []string{"/Library/Keychains/System.keychain"}
+
+	// Note that this results in trusting roots from $HOME/... (the environment
+	// variable), which might not be expected.
+	home, err := os.UserHomeDir()
+	if err != nil {
+		if debugDarwinRoots {
+			fmt.Fprintf(os.Stderr, "crypto/x509: can't get user home directory: %v\n", err)
+		}
+	} else {
+		keychains = append(keychains,
+			filepath.Join(home, "/Library/Keychains/login.keychain"),
+
+			// Fresh installs of Sierra use a slightly different path for the login keychain
+			filepath.Join(home, "/Library/Keychains/login.keychain-db"),
+		)
+	}
+
+	type rootCandidate struct {
+		c      *Certificate
+		system bool
+	}
+
+	var (
+		mu          sync.Mutex
+		roots       = NewCertPool()
+		numVerified int // number of execs of 'security verify-cert', for debug stats
+		wg          sync.WaitGroup
+		verifyCh    = make(chan rootCandidate)
+	)
+
+	// Using 4 goroutines to pipe into verify-cert seems to be
+	// about the best we can do. The verify-cert binary seems to
+	// just RPC to another server with coarse locking anyway, so
+	// running 16 at a time for instance doesn't help at all. Due
+	// to the "if hasPolicy" check below, though, we will rarely
+	// (or never) call verify-cert on stock macOS systems, though.
+	// The hope is that we only call verify-cert when the user has
+	// tweaked their trust policy. These 4 goroutines are only
+	// defensive in the pathological case of many trust edits.
+	for i := 0; i < 4; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for cert := range verifyCh {
+				sha1CapHex := fmt.Sprintf("%X", sha1.Sum(cert.c.Raw))
+
+				var valid bool
+				verifyChecks := 0
+				if hasPolicy[sha1CapHex] {
+					verifyChecks++
+					valid = verifyCertWithSystem(cert.c)
+				} else {
+					// Certificates not in SystemRootCertificates without user
+					// or admin trust settings are not trusted.
+					valid = cert.system
+				}
+
+				mu.Lock()
+				numVerified += verifyChecks
+				if valid {
+					roots.AddCert(cert.c)
+				}
+				mu.Unlock()
+			}
+		}()
+	}
+	err = forEachCertInKeychains(keychains, func(cert *Certificate) {
+		verifyCh <- rootCandidate{c: cert, system: false}
+	})
+	if err != nil {
+		close(verifyCh)
+		return nil, err
+	}
+	err = forEachCertInKeychains([]string{
+		"/System/Library/Keychains/SystemRootCertificates.keychain",
+	}, func(cert *Certificate) {
+		verifyCh <- rootCandidate{c: cert, system: true}
+	})
+	if err != nil {
+		close(verifyCh)
+		return nil, err
+	}
+	close(verifyCh)
+	wg.Wait()
+
+	if debugDarwinRoots {
+		fmt.Fprintf(os.Stderr, "crypto/x509: ran security verify-cert %d times\n", numVerified)
+	}
+
+	return roots, nil
+}
+
+func forEachCertInKeychains(paths []string, f func(*Certificate)) error {
+	args := append([]string{"find-certificate", "-a", "-p"}, paths...)
+	cmd := exec.Command("/usr/bin/security", args...)
+	data, err := cmd.Output()
+	if err != nil {
+		return err
+	}
+	for len(data) > 0 {
+		var block *pem.Block
+		block, data = pem.Decode(data)
+		if block == nil {
+			break
+		}
+		if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
+			continue
+		}
+		cert, err := ParseCertificate(block.Bytes)
+		if err != nil {
+			continue
+		}
+		f(cert)
+	}
+	return nil
+}
+
+func verifyCertWithSystem(cert *Certificate) bool {
+	data := pem.EncodeToMemory(&pem.Block{
+		Type: "CERTIFICATE", Bytes: cert.Raw,
+	})
+
+	f, err := ioutil.TempFile("", "cert")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "can't create temporary file for cert: %v", err)
+		return false
+	}
+	defer os.Remove(f.Name())
+	if _, err := f.Write(data); err != nil {
+		fmt.Fprintf(os.Stderr, "can't write temporary file for cert: %v", err)
+		return false
+	}
+	if err := f.Close(); err != nil {
+		fmt.Fprintf(os.Stderr, "can't write temporary file for cert: %v", err)
+		return false
+	}
+	cmd := exec.Command("/usr/bin/security", "verify-cert", "-p", "ssl", "-c", f.Name(), "-l", "-L")
+	var stderr bytes.Buffer
+	if debugDarwinRoots {
+		cmd.Stderr = &stderr
+	}
+	if err := cmd.Run(); err != nil {
+		if debugDarwinRoots {
+			fmt.Fprintf(os.Stderr, "crypto/x509: verify-cert rejected %s: %q\n", cert.Subject, bytes.TrimSpace(stderr.Bytes()))
+		}
+		return false
+	}
+	if debugDarwinRoots {
+		fmt.Fprintf(os.Stderr, "crypto/x509: verify-cert approved %s\n", cert.Subject)
+	}
+	return true
+}
+
+// getCertsWithTrustPolicy returns the set of certs that have a
+// possibly-altered trust policy. The keys of the map are capitalized
+// sha1 hex of the raw cert.
+// They are the certs that should be checked against `security
+// verify-cert` to see whether the user altered the default trust
+// settings. This code is only used for cgo-disabled builds.
+func getCertsWithTrustPolicy() (map[string]bool, error) {
+	set := map[string]bool{}
+	td, err := ioutil.TempDir("", "x509trustpolicy")
+	if err != nil {
+		return nil, err
+	}
+	defer os.RemoveAll(td)
+	run := func(file string, args ...string) error {
+		file = filepath.Join(td, file)
+		args = append(args, file)
+		cmd := exec.Command("/usr/bin/security", args...)
+		var stderr bytes.Buffer
+		cmd.Stderr = &stderr
+		if err := cmd.Run(); err != nil {
+			// If there are no trust settings, the
+			// `security trust-settings-export` command
+			// fails with:
+			//    exit status 1, SecTrustSettingsCreateExternalRepresentation: No Trust Settings were found.
+			// Rather than match on English substrings that are probably
+			// localized on macOS, just interpret any failure to mean that
+			// there are no trust settings.
+			if debugDarwinRoots {
+				fmt.Fprintf(os.Stderr, "crypto/x509: exec %q: %v, %s\n", cmd.Args, err, stderr.Bytes())
+			}
+			return nil
+		}
+
+		f, err := os.Open(file)
+		if err != nil {
+			return err
+		}
+		defer f.Close()
+
+		// Gather all the runs of 40 capitalized hex characters.
+		br := bufio.NewReader(f)
+		var hexBuf bytes.Buffer
+		for {
+			b, err := br.ReadByte()
+			isHex := ('A' <= b && b <= 'F') || ('0' <= b && b <= '9')
+			if isHex {
+				hexBuf.WriteByte(b)
+			} else {
+				if hexBuf.Len() == 40 {
+					set[hexBuf.String()] = true
+				}
+				hexBuf.Reset()
+			}
+			if err == io.EOF {
+				break
+			}
+			if err != nil {
+				return err
+			}
+		}
+
+		return nil
+	}
+	if err := run("user", "trust-settings-export"); err != nil {
+		return nil, fmt.Errorf("dump-trust-settings (user): %v", err)
+	}
+	if err := run("admin", "trust-settings-export", "-d"); err != nil {
+		return nil, fmt.Errorf("dump-trust-settings (admin): %v", err)
+	}
+	return set, nil
+}
--- a/tempfork/x509/root_darwin_arm64.go
+++ b/tempfork/x509/root_darwin_arm64.go
--- a/tempfork/x509/root_darwin_arm_gen.go
+++ b/tempfork/x509/root_darwin_arm_gen.go
@ -0,0 +1,184 @@
+// 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.
+
+// +build ignore
+
+// Generates root_darwin_arm64.go.
+//
+// As of iOS 8, there is no API for querying the system trusted X.509 root
+// certificates. We could use SecTrustEvaluate to verify that a trust chain
+// exists for a certificate, but the x509 API requires returning the entire
+// chain.
+//
+// Apple publishes the list of trusted root certificates for iOS on
+// support.apple.com. So we parse the list and extract the certificates from
+// an OS X machine and embed them into the x509 package.
+package main
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"crypto/x509"
+	"encoding/hex"
+	"encoding/pem"
+	"flag"
+	"fmt"
+	"go/format"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os/exec"
+	"regexp"
+	"strings"
+)
+
+var output = flag.String("output", "root_darwin_arm64.go", "file name to write")
+
+func main() {
+	certs, err := selectCerts()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	buf := new(bytes.Buffer)
+
+	fmt.Fprintf(buf, "// Code generated by root_darwin_arm_gen --output %s; DO NOT EDIT.\n", *output)
+	fmt.Fprintf(buf, "%s", header)
+
+	fmt.Fprintf(buf, "const systemRootsPEM = `\n")
+	for _, cert := range certs {
+		b := &pem.Block{
+			Type:  "CERTIFICATE",
+			Bytes: cert.Raw,
+		}
+		if err := pem.Encode(buf, b); err != nil {
+			log.Fatal(err)
+		}
+	}
+	fmt.Fprintf(buf, "`")
+
+	source, err := format.Source(buf.Bytes())
+	if err != nil {
+		log.Fatal("source format error:", err)
+	}
+	if err := ioutil.WriteFile(*output, source, 0644); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func selectCerts() ([]*x509.Certificate, error) {
+	ids, err := fetchCertIDs()
+	if err != nil {
+		return nil, err
+	}
+
+	scerts, err := sysCerts()
+	if err != nil {
+		return nil, err
+	}
+
+	var certs []*x509.Certificate
+	for _, id := range ids {
+		if c, ok := scerts[id.fingerprint]; ok {
+			certs = append(certs, c)
+		} else {
+			fmt.Printf("WARNING: cannot find certificate: %s (fingerprint: %s)\n", id.name, id.fingerprint)
+		}
+	}
+	return certs, nil
+}
+
+func sysCerts() (certs map[string]*x509.Certificate, err error) {
+	cmd := exec.Command("/usr/bin/security", "find-certificate", "-a", "-p", "/System/Library/Keychains/SystemRootCertificates.keychain")
+	data, err := cmd.Output()
+	if err != nil {
+		return nil, err
+	}
+	certs = make(map[string]*x509.Certificate)
+	for len(data) > 0 {
+		var block *pem.Block
+		block, data = pem.Decode(data)
+		if block == nil {
+			break
+		}
+		if block.Type != "CERTIFICATE" || len(block.Headers) != 0 {
+			continue
+		}
+
+		cert, err := x509.ParseCertificate(block.Bytes)
+		if err != nil {
+			continue
+		}
+
+		fingerprint := sha256.Sum256(cert.Raw)
+		certs[hex.EncodeToString(fingerprint[:])] = cert
+	}
+	return certs, nil
+}
+
+type certID struct {
+	name        string
+	fingerprint string
+}
+
+// fetchCertIDs fetches IDs of iOS X509 certificates from apple.com.
+func fetchCertIDs() ([]certID, error) {
+	// Download the iOS 11 support page. The index for all iOS versions is here:
+	// https://support.apple.com/en-us/HT204132
+	resp, err := http.Get("https://support.apple.com/en-us/HT208125")
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	text := string(body)
+	text = text[strings.Index(text, "<div id=trusted"):]
+	text = text[:strings.Index(text, "</div>")]
+
+	var ids []certID
+	cols := make(map[string]int)
+	for i, rowmatch := range regexp.MustCompile("(?s)<tr>(.*?)</tr>").FindAllStringSubmatch(text, -1) {
+		row := rowmatch[1]
+		if i == 0 {
+			// Parse table header row to extract column names
+			for i, match := range regexp.MustCompile("(?s)<th>(.*?)</th>").FindAllStringSubmatch(row, -1) {
+				cols[match[1]] = i
+			}
+			continue
+		}
+
+		values := regexp.MustCompile("(?s)<td>(.*?)</td>").FindAllStringSubmatch(row, -1)
+		name := values[cols["Certificate name"]][1]
+		fingerprint := values[cols["Fingerprint (SHA-256)"]][1]
+		fingerprint = strings.ReplaceAll(fingerprint, "<br>", "")
+		fingerprint = strings.ReplaceAll(fingerprint, "\n", "")
+		fingerprint = strings.ReplaceAll(fingerprint, " ", "")
+		fingerprint = strings.ToLower(fingerprint)
+
+		ids = append(ids, certID{
+			name:        name,
+			fingerprint: fingerprint,
+		})
+	}
+	return ids, nil
+}
+
+const header = `
+// 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.
+
+// +build !x509omitbundledroots
+
+package x509
+
+func loadSystemRoots() (*CertPool, error) {
+	p := NewCertPool()
+	p.AppendCertsFromPEM([]byte(systemRootsPEM))
+	return p, nil
+}
+`
--- a/tempfork/x509/root_darwin_test.go
+++ b/tempfork/x509/root_darwin_test.go
@ -0,0 +1,129 @@
+// Copyright 2013 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 x509
+
+import (
+	"crypto/rsa"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"testing"
+	"time"
+)
+
+func TestSystemRoots(t *testing.T) {
+	switch runtime.GOARCH {
+	case "arm64":
+		t.Skipf("skipping on %s/%s, no system root", runtime.GOOS, runtime.GOARCH)
+	}
+
+	t0 := time.Now()
+	sysRoots := systemRootsPool() // actual system roots
+	sysRootsDuration := time.Since(t0)
+
+	t1 := time.Now()
+	execRoots, err := execSecurityRoots() // non-cgo roots
+	execSysRootsDuration := time.Since(t1)
+
+	if err != nil {
+		t.Fatalf("failed to read system roots: %v", err)
+	}
+
+	t.Logf("    cgo sys roots: %v", sysRootsDuration)
+	t.Logf("non-cgo sys roots: %v", execSysRootsDuration)
+
+	// On Mavericks, there are 212 bundled certs, at least there was at
+	// one point in time on one machine. (Maybe it was a corp laptop
+	// with extra certs?) Other OS X users report 135, 142, 145...
+	// Let's try requiring at least 100, since this is just a sanity
+	// check.
+	if want, have := 100, len(sysRoots.certs); have < want {
+		t.Errorf("want at least %d system roots, have %d", want, have)
+	}
+
+	// Fetch any intermediate certificate that verify-cert might be aware of.
+	out, err := exec.Command("/usr/bin/security", "find-certificate", "-a", "-p",
+		"/Library/Keychains/System.keychain",
+		filepath.Join(os.Getenv("HOME"), "/Library/Keychains/login.keychain"),
+		filepath.Join(os.Getenv("HOME"), "/Library/Keychains/login.keychain-db")).Output()
+	if err != nil {
+		t.Fatal(err)
+	}
+	allCerts := NewCertPool()
+	allCerts.AppendCertsFromPEM(out)
+
+	// Check that the two cert pools are the same.
+	sysPool := make(map[string]*Certificate, len(sysRoots.certs))
+	for _, c := range sysRoots.certs {
+		sysPool[string(c.Raw)] = c
+	}
+	for _, c := range execRoots.certs {
+		if _, ok := sysPool[string(c.Raw)]; ok {
+			delete(sysPool, string(c.Raw))
+		} else {
+			// verify-cert lets in certificates that are not trusted roots, but
+			// are signed by trusted roots. This is not great, but unavoidable
+			// until we parse real policies without cgo, so confirm that's the
+			// case and skip them.
+			if _, err := c.Verify(VerifyOptions{
+				Roots:         sysRoots,
+				Intermediates: allCerts,
+				KeyUsages:     []ExtKeyUsage{ExtKeyUsageAny},
+				CurrentTime:   c.NotBefore, // verify-cert does not check expiration
+			}); err != nil {
+				t.Errorf("certificate only present in non-cgo pool: %v (verify error: %v)", c.Subject, err)
+			} else {
+				t.Logf("signed certificate only present in non-cgo pool (acceptable): %v", c.Subject)
+			}
+		}
+	}
+	for _, c := range sysPool {
+		// The nocgo codepath uses verify-cert with the ssl policy, which also
+		// happens to check EKUs, so some certificates will appear only in the
+		// cgo pool. We can't easily make them consistent because the EKU check
+		// is only applied to the certificates passed to verify-cert.
+		var ekuOk bool
+		for _, eku := range c.ExtKeyUsage {
+			if eku == ExtKeyUsageServerAuth || eku == ExtKeyUsageNetscapeServerGatedCrypto ||
+				eku == ExtKeyUsageMicrosoftServerGatedCrypto || eku == ExtKeyUsageAny {
+				ekuOk = true
+			}
+		}
+		if len(c.ExtKeyUsage) == 0 && len(c.UnknownExtKeyUsage) == 0 {
+			ekuOk = true
+		}
+		if !ekuOk {
+			t.Logf("off-EKU certificate only present in cgo pool (acceptable): %v", c.Subject)
+			continue
+		}
+
+		// Same for expired certificates. We don't chain to them anyway.
+		now := time.Now()
+		if now.Before(c.NotBefore) || now.After(c.NotAfter) {
+			t.Logf("expired certificate only present in cgo pool (acceptable): %v", c.Subject)
+			continue
+		}
+
+		// On 10.11 there are five unexplained roots that only show up from the
+		// C API. They have in common the fact that they are old, 1024-bit
+		// certificates. It's arguably better to ignore them anyway.
+		if key, ok := c.PublicKey.(*rsa.PublicKey); ok && key.N.BitLen() == 1024 {
+			t.Logf("1024-bit certificate only present in cgo pool (acceptable): %v", c.Subject)
+			continue
+		}
+
+		t.Errorf("certificate only present in cgo pool: %v", c.Subject)
+	}
+
+	if t.Failed() && debugDarwinRoots {
+		cmd := exec.Command("security", "dump-trust-settings")
+		cmd.Stdout, cmd.Stderr = os.Stderr, os.Stderr
+		cmd.Run()
+		cmd = exec.Command("security", "dump-trust-settings", "-d")
+		cmd.Stdout, cmd.Stderr = os.Stderr, os.Stderr
+		cmd.Run()
+	}
+}
--- a/tempfork/x509/root_js.go
+++ b/tempfork/x509/root_js.go
@ -0,0 +1,10 @@
+// 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.
+
+// +build js,wasm
+
+package x509
+
+// Possible certificate files; stop after finding one.
+var certFiles = []string{}
--- a/tempfork/x509/root_linux.go
+++ b/tempfork/x509/root_linux.go
@ -0,0 +1,15 @@
+// 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 x509
+
+// Possible certificate files; stop after finding one.
+var certFiles = []string{
+	"/etc/ssl/certs/ca-certificates.crt",                // Debian/Ubuntu/Gentoo etc.
+	"/etc/pki/tls/certs/ca-bundle.crt",                  // Fedora/RHEL 6
+	"/etc/ssl/ca-bundle.pem",                            // OpenSUSE
+	"/etc/pki/tls/cacert.pem",                           // OpenELEC
+	"/etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem", // CentOS/RHEL 7
+	"/etc/ssl/cert.pem",                                 // Alpine Linux
+}
--- a/tempfork/x509/root_nocgo_darwin.go
+++ b/tempfork/x509/root_nocgo_darwin.go
@ -0,0 +1,11 @@
+// Copyright 2013 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.
+
+// +build !cgo
+
+package x509
+
+func loadSystemRoots() (*CertPool, error) {
+	return execSecurityRoots()
+}
--- a/tempfork/x509/root_omit.go
+++ b/tempfork/x509/root_omit.go
@ -0,0 +1,21 @@
+// 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.
+
+// +build darwin,arm64,x509omitbundledroots
+
+// This file provides the loadSystemRoots func when the
+// "x509omitbundledroots" build tag has disabled bundling a copy,
+// which currently on happens on darwin/arm64 (root_darwin_arm64.go).
+// This then saves 256 KiB of binary size and another 560 KiB of
+// runtime memory size retaining the parsed roots forever. Constrained
+// environments can construct minimal x509 root CertPools on the fly
+// in the crypto/tls.Config.VerifyPeerCertificate hook.
+
+package x509
+
+import "errors"
+
+func loadSystemRoots() (*CertPool, error) {
+	return nil, errors.New("x509: system root bundling disabled")
+}
--- a/tempfork/x509/root_omit_test.go
+++ b/tempfork/x509/root_omit_test.go
@ -0,0 +1,22 @@
+// 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.
+
+// +build darwin,arm64,x509omitbundledroots
+
+package x509
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestOmitBundledRoots(t *testing.T) {
+	cp, err := loadSystemRoots()
+	if err == nil {
+		t.Fatalf("loadSystemRoots = (pool %p, error %v); want non-nil error", cp, err)
+	}
+	if !strings.Contains(err.Error(), "root bundling disabled") {
+		t.Errorf("unexpected error doesn't mention bundling: %v", err)
+	}
+}
--- a/tempfork/x509/root_plan9.go
+++ b/tempfork/x509/root_plan9.go
@ -0,0 +1,40 @@
+// Copyright 2012 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.
+
+// +build plan9
+
+package x509
+
+import (
+	"io/ioutil"
+	"os"
+)
+
+// Possible certificate files; stop after finding one.
+var certFiles = []string{
+	"/sys/lib/tls/ca.pem",
+}
+
+func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
+	return nil, nil
+}
+
+func loadSystemRoots() (*CertPool, error) {
+	roots := NewCertPool()
+	var bestErr error
+	for _, file := range certFiles {
+		data, err := ioutil.ReadFile(file)
+		if err == nil {
+			roots.AppendCertsFromPEM(data)
+			return roots, nil
+		}
+		if bestErr == nil || (os.IsNotExist(bestErr) && !os.IsNotExist(err)) {
+			bestErr = err
+		}
+	}
+	if bestErr == nil {
+		return roots, nil
+	}
+	return nil, bestErr
+}
--- a/tempfork/x509/root_solaris.go
+++ b/tempfork/x509/root_solaris.go
@ -0,0 +1,12 @@
+// 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 x509
+
+// Possible certificate files; stop after finding one.
+var certFiles = []string{
+	"/etc/certs/ca-certificates.crt",     // Solaris 11.2+
+	"/etc/ssl/certs/ca-certificates.crt", // Joyent SmartOS
+	"/etc/ssl/cacert.pem",                // OmniOS
+}
--- a/tempfork/x509/root_unix.go
+++ b/tempfork/x509/root_unix.go
@ -0,0 +1,92 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build aix dragonfly freebsd js,wasm linux netbsd openbsd solaris
+
+package x509
+
+import (
+	"io/ioutil"
+	"os"
+	"strings"
+)
+
+// Possible directories with certificate files; stop after successfully
+// reading at least one file from a directory.
+var certDirectories = []string{
+	"/etc/ssl/certs",               // SLES10/SLES11, https://golang.org/issue/12139
+	"/system/etc/security/cacerts", // Android
+	"/usr/local/share/certs",       // FreeBSD
+	"/etc/pki/tls/certs",           // Fedora/RHEL
+	"/etc/openssl/certs",           // NetBSD
+	"/var/ssl/certs",               // AIX
+}
+
+const (
+	// certFileEnv is the environment variable which identifies where to locate
+	// the SSL certificate file. If set this overrides the system default.
+	certFileEnv = "SSL_CERT_FILE"
+
+	// certDirEnv is the environment variable which identifies which directory
+	// to check for SSL certificate files. If set this overrides the system default.
+	// It is a colon separated list of directories.
+	// See https://www.openssl.org/docs/man1.0.2/man1/c_rehash.html.
+	certDirEnv = "SSL_CERT_DIR"
+)
+
+func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
+	return nil, nil
+}
+
+func loadSystemRoots() (*CertPool, error) {
+	roots := NewCertPool()
+
+	files := certFiles
+	if f := os.Getenv(certFileEnv); f != "" {
+		files = []string{f}
+	}
+
+	var firstErr error
+	for _, file := range files {
+		data, err := ioutil.ReadFile(file)
+		if err == nil {
+			roots.AppendCertsFromPEM(data)
+			break
+		}
+		if firstErr == nil && !os.IsNotExist(err) {
+			firstErr = err
+		}
+	}
+
+	dirs := certDirectories
+	if d := os.Getenv(certDirEnv); d != "" {
+		// OpenSSL and BoringSSL both use ":" as the SSL_CERT_DIR separator.
+		// See:
+		//  * https://golang.org/issue/35325
+		//  * https://www.openssl.org/docs/man1.0.2/man1/c_rehash.html
+		dirs = strings.Split(d, ":")
+	}
+
+	for _, directory := range dirs {
+		fis, err := ioutil.ReadDir(directory)
+		if err != nil {
+			if firstErr == nil && !os.IsNotExist(err) {
+				firstErr = err
+			}
+			continue
+		}
+		for _, fi := range fis {
+			data, err := ioutil.ReadFile(directory + "/" + fi.Name())
+			if err == nil {
+				roots.AppendCertsFromPEM(data)
+			}
+		}
+	}
+
+	if len(roots.certs) > 0 || firstErr == nil {
+		return roots, nil
+	}
+
+	return nil, firstErr
+}
--- a/tempfork/x509/root_unix_test.go
+++ b/tempfork/x509/root_unix_test.go
@ -0,0 +1,204 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build dragonfly freebsd linux netbsd openbsd solaris
+
+package x509
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+const (
+	testDir     = "testdata"
+	testDirCN   = "test-dir"
+	testFile    = "test-file.crt"
+	testFileCN  = "test-file"
+	testMissing = "missing"
+)
+
+func TestEnvVars(t *testing.T) {
+	testCases := []struct {
+		name    string
+		fileEnv string
+		dirEnv  string
+		files   []string
+		dirs    []string
+		cns     []string
+	}{
+		{
+			// Environment variables override the default locations preventing fall through.
+			name:    "override-defaults",
+			fileEnv: testMissing,
+			dirEnv:  testMissing,
+			files:   []string{testFile},
+			dirs:    []string{testDir},
+			cns:     nil,
+		},
+		{
+			// File environment overrides default file locations.
+			name:    "file",
+			fileEnv: testFile,
+			dirEnv:  "",
+			files:   nil,
+			dirs:    nil,
+			cns:     []string{testFileCN},
+		},
+		{
+			// Directory environment overrides default directory locations.
+			name:    "dir",
+			fileEnv: "",
+			dirEnv:  testDir,
+			files:   nil,
+			dirs:    nil,
+			cns:     []string{testDirCN},
+		},
+		{
+			// File & directory environment overrides both default locations.
+			name:    "file+dir",
+			fileEnv: testFile,
+			dirEnv:  testDir,
+			files:   nil,
+			dirs:    nil,
+			cns:     []string{testFileCN, testDirCN},
+		},
+		{
+			// Environment variable empty / unset uses default locations.
+			name:    "empty-fall-through",
+			fileEnv: "",
+			dirEnv:  "",
+			files:   []string{testFile},
+			dirs:    []string{testDir},
+			cns:     []string{testFileCN, testDirCN},
+		},
+	}
+
+	// Save old settings so we can restore before the test ends.
+	origCertFiles, origCertDirectories := certFiles, certDirectories
+	origFile, origDir := os.Getenv(certFileEnv), os.Getenv(certDirEnv)
+	defer func() {
+		certFiles = origCertFiles
+		certDirectories = origCertDirectories
+		os.Setenv(certFileEnv, origFile)
+		os.Setenv(certDirEnv, origDir)
+	}()
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			if err := os.Setenv(certFileEnv, tc.fileEnv); err != nil {
+				t.Fatalf("setenv %q failed: %v", certFileEnv, err)
+			}
+			if err := os.Setenv(certDirEnv, tc.dirEnv); err != nil {
+				t.Fatalf("setenv %q failed: %v", certDirEnv, err)
+			}
+
+			certFiles, certDirectories = tc.files, tc.dirs
+
+			r, err := loadSystemRoots()
+			if err != nil {
+				t.Fatal("unexpected failure:", err)
+			}
+
+			if r == nil {
+				t.Fatal("nil roots")
+			}
+
+			// Verify that the returned certs match, otherwise report where the mismatch is.
+			for i, cn := range tc.cns {
+				if i >= len(r.certs) {
+					t.Errorf("missing cert %v @ %v", cn, i)
+				} else if r.certs[i].Subject.CommonName != cn {
+					fmt.Printf("%#v\n", r.certs[0].Subject)
+					t.Errorf("unexpected cert common name %q, want %q", r.certs[i].Subject.CommonName, cn)
+				}
+			}
+			if len(r.certs) > len(tc.cns) {
+				t.Errorf("got %v certs, which is more than %v wanted", len(r.certs), len(tc.cns))
+			}
+		})
+	}
+}
+
+// Ensure that "SSL_CERT_DIR" when used as the environment
+// variable delimited by colons, allows loadSystemRoots to
+// load all the roots from the respective directories.
+// See https://golang.org/issue/35325.
+func TestLoadSystemCertsLoadColonSeparatedDirs(t *testing.T) {
+	origFile, origDir := os.Getenv(certFileEnv), os.Getenv(certDirEnv)
+	origCertFiles := certFiles[:]
+
+	// To prevent any other certs from being loaded in
+	// through "SSL_CERT_FILE" or from known "certFiles",
+	// clear them all, and they'll be reverting on defer.
+	certFiles = certFiles[:0]
+	os.Setenv(certFileEnv, "")
+
+	defer func() {
+		certFiles = origCertFiles[:]
+		os.Setenv(certDirEnv, origDir)
+		os.Setenv(certFileEnv, origFile)
+	}()
+
+	tmpDir, err := ioutil.TempDir(os.TempDir(), "x509-issue35325")
+	if err != nil {
+		t.Fatalf("Failed to create temporary directory: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	rootPEMs := []string{
+		geoTrustRoot,
+		googleLeaf,
+		startComRoot,
+	}
+
+	var certDirs []string
+	for i, certPEM := range rootPEMs {
+		certDir := filepath.Join(tmpDir, fmt.Sprintf("cert-%d", i))
+		if err := os.MkdirAll(certDir, 0755); err != nil {
+			t.Fatalf("Failed to create certificate dir: %v", err)
+		}
+		certOutFile := filepath.Join(certDir, "cert.crt")
+		if err := ioutil.WriteFile(certOutFile, []byte(certPEM), 0655); err != nil {
+			t.Fatalf("Failed to write certificate to file: %v", err)
+		}
+		certDirs = append(certDirs, certDir)
+	}
+
+	// Sanity check: the number of certDirs should be equal to the number of roots.
+	if g, w := len(certDirs), len(rootPEMs); g != w {
+		t.Fatalf("Failed sanity check: len(certsDir)=%d is not equal to len(rootsPEMS)=%d", g, w)
+	}
+
+	// Now finally concatenate them with a colon.
+	colonConcatCertDirs := strings.Join(certDirs, ":")
+	os.Setenv(certDirEnv, colonConcatCertDirs)
+	gotPool, err := loadSystemRoots()
+	if err != nil {
+		t.Fatalf("Failed to load system roots: %v", err)
+	}
+	subjects := gotPool.Subjects()
+	// We expect exactly len(rootPEMs) subjects back.
+	if g, w := len(subjects), len(rootPEMs); g != w {
+		t.Fatalf("Invalid number of subjects: got %d want %d", g, w)
+	}
+
+	wantPool := NewCertPool()
+	for _, certPEM := range rootPEMs {
+		wantPool.AppendCertsFromPEM([]byte(certPEM))
+	}
+	strCertPool := func(p *CertPool) string {
+		return string(bytes.Join(p.Subjects(), []byte("\n")))
+	}
+	if !reflect.DeepEqual(gotPool, wantPool) {
+		g, w := strCertPool(gotPool), strCertPool(wantPool)
+		t.Fatalf("Mismatched certPools\nGot:\n%s\n\nWant:\n%s", g, w)
+	}
+}
--- a/tempfork/x509/root_windows.go
+++ b/tempfork/x509/root_windows.go
@ -0,0 +1,286 @@
+// Copyright 2012 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 x509
+
+import (
+	"errors"
+	"syscall"
+	"unsafe"
+)
+
+// Creates a new *syscall.CertContext representing the leaf certificate in an in-memory
+// certificate store containing itself and all of the intermediate certificates specified
+// in the opts.Intermediates CertPool.
+//
+// A pointer to the in-memory store is available in the returned CertContext's Store field.
+// The store is automatically freed when the CertContext is freed using
+// syscall.CertFreeCertificateContext.
+func createStoreContext(leaf *Certificate, opts *VerifyOptions) (*syscall.CertContext, error) {
+	var storeCtx *syscall.CertContext
+
+	leafCtx, err := syscall.CertCreateCertificateContext(syscall.X509_ASN_ENCODING|syscall.PKCS_7_ASN_ENCODING, &leaf.Raw[0], uint32(len(leaf.Raw)))
+	if err != nil {
+		return nil, err
+	}
+	defer syscall.CertFreeCertificateContext(leafCtx)
+
+	handle, err := syscall.CertOpenStore(syscall.CERT_STORE_PROV_MEMORY, 0, 0, syscall.CERT_STORE_DEFER_CLOSE_UNTIL_LAST_FREE_FLAG, 0)
+	if err != nil {
+		return nil, err
+	}
+	defer syscall.CertCloseStore(handle, 0)
+
+	err = syscall.CertAddCertificateContextToStore(handle, leafCtx, syscall.CERT_STORE_ADD_ALWAYS, &storeCtx)
+	if err != nil {
+		return nil, err
+	}
+
+	if opts.Intermediates != nil {
+		for _, intermediate := range opts.Intermediates.certs {
+			ctx, err := syscall.CertCreateCertificateContext(syscall.X509_ASN_ENCODING|syscall.PKCS_7_ASN_ENCODING, &intermediate.Raw[0], uint32(len(intermediate.Raw)))
+			if err != nil {
+				return nil, err
+			}
+
+			err = syscall.CertAddCertificateContextToStore(handle, ctx, syscall.CERT_STORE_ADD_ALWAYS, nil)
+			syscall.CertFreeCertificateContext(ctx)
+			if err != nil {
+				return nil, err
+			}
+		}
+	}
+
+	return storeCtx, nil
+}
+
+// extractSimpleChain extracts the final certificate chain from a CertSimpleChain.
+func extractSimpleChain(simpleChain **syscall.CertSimpleChain, count int) (chain []*Certificate, err error) {
+	if simpleChain == nil || count == 0 {
+		return nil, errors.New("x509: invalid simple chain")
+	}
+
+	simpleChains := (*[1 << 20]*syscall.CertSimpleChain)(unsafe.Pointer(simpleChain))[:count:count]
+	lastChain := simpleChains[count-1]
+	elements := (*[1 << 20]*syscall.CertChainElement)(unsafe.Pointer(lastChain.Elements))[:lastChain.NumElements:lastChain.NumElements]
+	for i := 0; i < int(lastChain.NumElements); i++ {
+		// Copy the buf, since ParseCertificate does not create its own copy.
+		cert := elements[i].CertContext
+		encodedCert := (*[1 << 20]byte)(unsafe.Pointer(cert.EncodedCert))[:cert.Length:cert.Length]
+		buf := make([]byte, cert.Length)
+		copy(buf, encodedCert)
+		parsedCert, err := ParseCertificate(buf)
+		if err != nil {
+			return nil, err
+		}
+		chain = append(chain, parsedCert)
+	}
+
+	return chain, nil
+}
+
+// checkChainTrustStatus checks the trust status of the certificate chain, translating
+// any errors it finds into Go errors in the process.
+func checkChainTrustStatus(c *Certificate, chainCtx *syscall.CertChainContext) error {
+	if chainCtx.TrustStatus.ErrorStatus != syscall.CERT_TRUST_NO_ERROR {
+		status := chainCtx.TrustStatus.ErrorStatus
+		switch status {
+		case syscall.CERT_TRUST_IS_NOT_TIME_VALID:
+			return CertificateInvalidError{c, Expired, ""}
+		default:
+			return UnknownAuthorityError{c, nil, nil}
+		}
+	}
+	return nil
+}
+
+// checkChainSSLServerPolicy checks that the certificate chain in chainCtx is valid for
+// use as a certificate chain for a SSL/TLS server.
+func checkChainSSLServerPolicy(c *Certificate, chainCtx *syscall.CertChainContext, opts *VerifyOptions) error {
+	servernamep, err := syscall.UTF16PtrFromString(opts.DNSName)
+	if err != nil {
+		return err
+	}
+	sslPara := &syscall.SSLExtraCertChainPolicyPara{
+		AuthType:   syscall.AUTHTYPE_SERVER,
+		ServerName: servernamep,
+	}
+	sslPara.Size = uint32(unsafe.Sizeof(*sslPara))
+
+	para := &syscall.CertChainPolicyPara{
+		ExtraPolicyPara: (syscall.Pointer)(unsafe.Pointer(sslPara)),
+	}
+	para.Size = uint32(unsafe.Sizeof(*para))
+
+	status := syscall.CertChainPolicyStatus{}
+	err = syscall.CertVerifyCertificateChainPolicy(syscall.CERT_CHAIN_POLICY_SSL, chainCtx, para, &status)
+	if err != nil {
+		return err
+	}
+
+	// TODO(mkrautz): use the lChainIndex and lElementIndex fields
+	// of the CertChainPolicyStatus to provide proper context, instead
+	// using c.
+	if status.Error != 0 {
+		switch status.Error {
+		case syscall.CERT_E_EXPIRED:
+			return CertificateInvalidError{c, Expired, ""}
+		case syscall.CERT_E_CN_NO_MATCH:
+			return HostnameError{c, opts.DNSName}
+		case syscall.CERT_E_UNTRUSTEDROOT:
+			return UnknownAuthorityError{c, nil, nil}
+		default:
+			return UnknownAuthorityError{c, nil, nil}
+		}
+	}
+
+	return nil
+}
+
+// systemVerify is like Verify, except that it uses CryptoAPI calls
+// to build certificate chains and verify them.
+func (c *Certificate) systemVerify(opts *VerifyOptions) (chains [][]*Certificate, err error) {
+	hasDNSName := opts != nil && len(opts.DNSName) > 0
+
+	storeCtx, err := createStoreContext(c, opts)
+	if err != nil {
+		return nil, err
+	}
+	defer syscall.CertFreeCertificateContext(storeCtx)
+
+	para := new(syscall.CertChainPara)
+	para.Size = uint32(unsafe.Sizeof(*para))
+
+	// If there's a DNSName set in opts, assume we're verifying
+	// a certificate from a TLS server.
+	if hasDNSName {
+		oids := []*byte{
+			&syscall.OID_PKIX_KP_SERVER_AUTH[0],
+			// Both IE and Chrome allow certificates with
+			// Server Gated Crypto as well. Some certificates
+			// in the wild require them.
+			&syscall.OID_SERVER_GATED_CRYPTO[0],
+			&syscall.OID_SGC_NETSCAPE[0],
+		}
+		para.RequestedUsage.Type = syscall.USAGE_MATCH_TYPE_OR
+		para.RequestedUsage.Usage.Length = uint32(len(oids))
+		para.RequestedUsage.Usage.UsageIdentifiers = &oids[0]
+	} else {
+		para.RequestedUsage.Type = syscall.USAGE_MATCH_TYPE_AND
+		para.RequestedUsage.Usage.Length = 0
+		para.RequestedUsage.Usage.UsageIdentifiers = nil
+	}
+
+	var verifyTime *syscall.Filetime
+	if opts != nil && !opts.CurrentTime.IsZero() {
+		ft := syscall.NsecToFiletime(opts.CurrentTime.UnixNano())
+		verifyTime = &ft
+	}
+
+	// CertGetCertificateChain will traverse Windows's root stores
+	// in an attempt to build a verified certificate chain. Once
+	// it has found a verified chain, it stops. MSDN docs on
+	// CERT_CHAIN_CONTEXT:
+	//
+	//   When a CERT_CHAIN_CONTEXT is built, the first simple chain
+	//   begins with an end certificate and ends with a self-signed
+	//   certificate. If that self-signed certificate is not a root
+	//   or otherwise trusted certificate, an attempt is made to
+	//   build a new chain. CTLs are used to create the new chain
+	//   beginning with the self-signed certificate from the original
+	//   chain as the end certificate of the new chain. This process
+	//   continues building additional simple chains until the first
+	//   self-signed certificate is a trusted certificate or until
+	//   an additional simple chain cannot be built.
+	//
+	// The result is that we'll only get a single trusted chain to
+	// return to our caller.
+	var chainCtx *syscall.CertChainContext
+	err = syscall.CertGetCertificateChain(syscall.Handle(0), storeCtx, verifyTime, storeCtx.Store, para, 0, 0, &chainCtx)
+	if err != nil {
+		return nil, err
+	}
+	defer syscall.CertFreeCertificateChain(chainCtx)
+
+	err = checkChainTrustStatus(c, chainCtx)
+	if err != nil {
+		return nil, err
+	}
+
+	if hasDNSName {
+		err = checkChainSSLServerPolicy(c, chainCtx, opts)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	chain, err := extractSimpleChain(chainCtx.Chains, int(chainCtx.ChainCount))
+	if err != nil {
+		return nil, err
+	}
+	if len(chain) < 1 {
+		return nil, errors.New("x509: internal error: system verifier returned an empty chain")
+	}
+
+	// Mitigate CVE-2020-0601, where the Windows system verifier might be
+	// tricked into using custom curve parameters for a trusted root, by
+	// double-checking all ECDSA signatures. If the system was tricked into
+	// using spoofed parameters, the signature will be invalid for the correct
+	// ones we parsed. (We don't support custom curves ourselves.)
+	for i, parent := range chain[1:] {
+		if parent.PublicKeyAlgorithm != ECDSA {
+			continue
+		}
+		if err := parent.CheckSignature(chain[i].SignatureAlgorithm,
+			chain[i].RawTBSCertificate, chain[i].Signature); err != nil {
+			return nil, err
+		}
+	}
+
+	return [][]*Certificate{chain}, nil
+}
+
+func loadSystemRoots() (*CertPool, error) {
+	// TODO: restore this functionality on Windows. We tried to do
+	// it in Go 1.8 but had to revert it. See Issue 18609.
+	// Returning (nil, nil) was the old behavior, prior to CL 30578.
+	// The if statement here avoids vet complaining about
+	// unreachable code below.
+	if true {
+		return nil, nil
+	}
+
+	const CRYPT_E_NOT_FOUND = 0x80092004
+
+	store, err := syscall.CertOpenSystemStore(0, syscall.StringToUTF16Ptr("ROOT"))
+	if err != nil {
+		return nil, err
+	}
+	defer syscall.CertCloseStore(store, 0)
+
+	roots := NewCertPool()
+	var cert *syscall.CertContext
+	for {
+		cert, err = syscall.CertEnumCertificatesInStore(store, cert)
+		if err != nil {
+			if errno, ok := err.(syscall.Errno); ok {
+				if errno == CRYPT_E_NOT_FOUND {
+					break
+				}
+			}
+			return nil, err
+		}
+		if cert == nil {
+			break
+		}
+		// Copy the buf, since ParseCertificate does not create its own copy.
+		buf := (*[1 << 20]byte)(unsafe.Pointer(cert.EncodedCert))[:cert.Length:cert.Length]
+		buf2 := make([]byte, cert.Length)
+		copy(buf2, buf)
+		if c, err := ParseCertificate(buf2); err == nil {
+			roots.AddCert(c)
+		}
+	}
+	return roots, nil
+}
--- a/tempfork/x509/sec1.go
+++ b/tempfork/x509/sec1.go
@ -0,0 +1,123 @@
+// Copyright 2012 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 x509
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"encoding/asn1"
+	"errors"
+	"fmt"
+	"math/big"
+)
+
+const ecPrivKeyVersion = 1
+
+// ecPrivateKey reflects an ASN.1 Elliptic Curve Private Key Structure.
+// References:
+//   RFC 5915
+//   SEC1 - http://www.secg.org/sec1-v2.pdf
+// Per RFC 5915 the NamedCurveOID is marked as ASN.1 OPTIONAL, however in
+// most cases it is not.
+type ecPrivateKey struct {
+	Version       int
+	PrivateKey    []byte
+	NamedCurveOID asn1.ObjectIdentifier `asn1:"optional,explicit,tag:0"`
+	PublicKey     asn1.BitString        `asn1:"optional,explicit,tag:1"`
+}
+
+// ParseECPrivateKey parses an EC private key in SEC 1, ASN.1 DER form.
+//
+// This kind of key is commonly encoded in PEM blocks of type "EC PRIVATE KEY".
+func ParseECPrivateKey(der []byte) (*ecdsa.PrivateKey, error) {
+	return parseECPrivateKey(nil, der)
+}
+
+// MarshalECPrivateKey converts an EC private key to SEC 1, ASN.1 DER form.
+//
+// This kind of key is commonly encoded in PEM blocks of type "EC PRIVATE KEY".
+// For a more flexible key format which is not EC specific, use
+// MarshalPKCS8PrivateKey.
+func MarshalECPrivateKey(key *ecdsa.PrivateKey) ([]byte, error) {
+	oid, ok := oidFromNamedCurve(key.Curve)
+	if !ok {
+		return nil, errors.New("x509: unknown elliptic curve")
+	}
+
+	return marshalECPrivateKeyWithOID(key, oid)
+}
+
+// marshalECPrivateKey marshals an EC private key into ASN.1, DER format and
+// sets the curve ID to the given OID, or omits it if OID is nil.
+func marshalECPrivateKeyWithOID(key *ecdsa.PrivateKey, oid asn1.ObjectIdentifier) ([]byte, error) {
+	privateKeyBytes := key.D.Bytes()
+	paddedPrivateKey := make([]byte, (key.Curve.Params().N.BitLen()+7)/8)
+	copy(paddedPrivateKey[len(paddedPrivateKey)-len(privateKeyBytes):], privateKeyBytes)
+
+	return asn1.Marshal(ecPrivateKey{
+		Version:       1,
+		PrivateKey:    paddedPrivateKey,
+		NamedCurveOID: oid,
+		PublicKey:     asn1.BitString{Bytes: elliptic.Marshal(key.Curve, key.X, key.Y)},
+	})
+}
+
+// parseECPrivateKey parses an ASN.1 Elliptic Curve Private Key Structure.
+// The OID for the named curve may be provided from another source (such as
+// the PKCS8 container) - if it is provided then use this instead of the OID
+// that may exist in the EC private key structure.
+func parseECPrivateKey(namedCurveOID *asn1.ObjectIdentifier, der []byte) (key *ecdsa.PrivateKey, err error) {
+	var privKey ecPrivateKey
+	if _, err := asn1.Unmarshal(der, &privKey); err != nil {
+		if _, err := asn1.Unmarshal(der, &pkcs8{}); err == nil {
+			return nil, errors.New("x509: failed to parse private key (use ParsePKCS8PrivateKey instead for this key format)")
+		}
+		if _, err := asn1.Unmarshal(der, &pkcs1PrivateKey{}); err == nil {
+			return nil, errors.New("x509: failed to parse private key (use ParsePKCS1PrivateKey instead for this key format)")
+		}
+		return nil, errors.New("x509: failed to parse EC private key: " + err.Error())
+	}
+	if privKey.Version != ecPrivKeyVersion {
+		return nil, fmt.Errorf("x509: unknown EC private key version %d", privKey.Version)
+	}
+
+	var curve elliptic.Curve
+	if namedCurveOID != nil {
+		curve = namedCurveFromOID(*namedCurveOID)
+	} else {
+		curve = namedCurveFromOID(privKey.NamedCurveOID)
+	}
+	if curve == nil {
+		return nil, errors.New("x509: unknown elliptic curve")
+	}
+
+	k := new(big.Int).SetBytes(privKey.PrivateKey)
+	curveOrder := curve.Params().N
+	if k.Cmp(curveOrder) >= 0 {
+		return nil, errors.New("x509: invalid elliptic curve private key value")
+	}
+	priv := new(ecdsa.PrivateKey)
+	priv.Curve = curve
+	priv.D = k
+
+	privateKey := make([]byte, (curveOrder.BitLen()+7)/8)
+
+	// Some private keys have leading zero padding. This is invalid
+	// according to [SEC1], but this code will ignore it.
+	for len(privKey.PrivateKey) > len(privateKey) {
+		if privKey.PrivateKey[0] != 0 {
+			return nil, errors.New("x509: invalid private key length")
+		}
+		privKey.PrivateKey = privKey.PrivateKey[1:]
+	}
+
+	// Some private keys remove all leading zeros, this is also invalid
+	// according to [SEC1] but since OpenSSL used to do this, we ignore
+	// this too.
+	copy(privateKey[len(privateKey)-len(privKey.PrivateKey):], privKey.PrivateKey)
+	priv.X, priv.Y = curve.ScalarBaseMult(privateKey)
+
+	return priv, nil
+}
--- a/tempfork/x509/sec1_test.go
+++ b/tempfork/x509/sec1_test.go
@ -0,0 +1,66 @@
+// Copyright 2012 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 x509
+
+import (
+	"bytes"
+	"encoding/hex"
+	"strings"
+	"testing"
+)
+
+var ecKeyTests = []struct {
+	derHex            string
+	shouldReserialize bool
+}{
+	// Generated using:
+	//   openssl ecparam -genkey -name secp384r1 -outform PEM
+	{"3081a40201010430bdb9839c08ee793d1157886a7a758a3c8b2a17a4df48f17ace57c72c56b4723cf21dcda21d4e1ad57ff034f19fcfd98ea00706052b81040022a16403620004feea808b5ee2429cfcce13c32160e1c960990bd050bb0fdf7222f3decd0a55008e32a6aa3c9062051c4cba92a7a3b178b24567412d43cdd2f882fa5addddd726fe3e208d2c26d733a773a597abb749714df7256ead5105fa6e7b3650de236b50", true},
+	// This key was generated by GnuTLS and has illegal zero-padding of the
+	// private key. See https://golang.org/issues/13699.
+	{"3078020101042100f9f43a04b9bdc3ab01f53be6df80e7a7bc3eaf7b87fc24e630a4a0aa97633645a00a06082a8648ce3d030107a1440342000441a51bc318461b4c39a45048a16d4fc2a935b1ea7fe86e8c1fa219d6f2438f7c7fd62957d3442efb94b6a23eb0ea66dda663dc42f379cda6630b21b7888a5d3d", false},
+	// This was generated using an old version of OpenSSL and is missing a
+	// leading zero byte in the private key that should be present.
+	{"3081db0201010441607b4f985774ac21e633999794542e09312073480baa69550914d6d43d8414441e61b36650567901da714f94dffb3ce0e2575c31928a0997d51df5c440e983ca17a00706052b81040023a181890381860004001661557afedd7ac8d6b70e038e576558c626eb62edda36d29c3a1310277c11f67a8c6f949e5430a37dcfb95d902c1b5b5379c389873b9dd17be3bdb088a4774a7401072f830fb9a08d93bfa50a03dd3292ea07928724ddb915d831917a338f6b0aecfbc3cf5352c4a1295d356890c41c34116d29eeb93779aab9d9d78e2613437740f6", false},
+}
+
+func TestParseECPrivateKey(t *testing.T) {
+	for i, test := range ecKeyTests {
+		derBytes, _ := hex.DecodeString(test.derHex)
+		key, err := ParseECPrivateKey(derBytes)
+		if err != nil {
+			t.Fatalf("#%d: failed to decode EC private key: %s", i, err)
+		}
+		serialized, err := MarshalECPrivateKey(key)
+		if err != nil {
+			t.Fatalf("#%d: failed to encode EC private key: %s", i, err)
+		}
+		matches := bytes.Equal(serialized, derBytes)
+		if matches != test.shouldReserialize {
+			t.Fatalf("#%d: when serializing key: matches=%t, should match=%t: original %x, reserialized %x", i, matches, test.shouldReserialize, serialized, derBytes)
+		}
+	}
+}
+
+const hexECTestPKCS1Key = "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"
+const hexECTestPKCS8Key = "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"
+
+var ecMismatchKeyTests = []struct {
+	hexKey        string
+	errorContains string
+}{
+	{hexKey: hexECTestPKCS8Key, errorContains: "use ParsePKCS8PrivateKey instead"},
+	{hexKey: hexECTestPKCS1Key, errorContains: "use ParsePKCS1PrivateKey instead"},
+}
+
+func TestECMismatchKeyFormat(t *testing.T) {
+	for i, test := range ecMismatchKeyTests {
+		derBytes, _ := hex.DecodeString(test.hexKey)
+		_, err := ParseECPrivateKey(derBytes)
+		if !strings.Contains(err.Error(), test.errorContains) {
+			t.Errorf("#%d: expected error containing %q, got %s", i, test.errorContains, err)
+		}
+	}
+}
--- a/tempfork/x509/test-file.crt
+++ b/tempfork/x509/test-file.crt
@ -0,0 +1,32 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
--- a/tempfork/x509/testdata/test-dir.crt
+++ b/tempfork/x509/testdata/test-dir.crt
@ -0,0 +1,31 @@
+-----BEGIN CERTIFICATE-----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=
+-----END CERTIFICATE-----
--- a/tempfork/x509/verify.go
+++ b/tempfork/x509/verify.go
--- a/tempfork/x509/verify_test.go
+++ b/tempfork/x509/verify_test.go
--- a/tempfork/x509/x509.go
+++ b/tempfork/x509/x509.go
--- a/tempfork/x509/x509_test.go
+++ b/tempfork/x509/x509_test.go
--- a/tempfork/x509/x509_test_import.go
+++ b/tempfork/x509/x509_test_import.go
@ -0,0 +1,56 @@
+// Copyright 2013 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.
+
+// +build ignore
+
+// This file is run by the x509 tests to ensure that a program with minimal
+// imports can sign certificates without errors resulting from missing hash
+// functions.
+package main
+
+import (
+	"crypto/rand"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
+	"math/big"
+	"strings"
+	"time"
+)
+
+func main() {
+	block, _ := pem.Decode([]byte(pemPrivateKey))
+	rsaPriv, err := x509.ParsePKCS1PrivateKey(block.Bytes)
+	if err != nil {
+		panic("Failed to parse private key: " + err.Error())
+	}
+
+	template := x509.Certificate{
+		SerialNumber: big.NewInt(1),
+		Subject: pkix.Name{
+			CommonName:   "test",
+			Organization: []string{"Σ Acme Co"},
+		},
+		NotBefore: time.Unix(1000, 0),
+		NotAfter:  time.Unix(100000, 0),
+		KeyUsage:  x509.KeyUsageCertSign,
+	}
+
+	if _, err = x509.CreateCertificate(rand.Reader, &template, &template, &rsaPriv.PublicKey, rsaPriv); err != nil {
+		panic("failed to create certificate with basic imports: " + err.Error())
+	}
+}
+
+var pemPrivateKey = testingKey(`-----BEGIN RSA TESTING KEY-----
+MIIBOgIBAAJBALKZD0nEffqM1ACuak0bijtqE2QrI/KLADv7l3kK3ppMyCuLKoF0
+fd7Ai2KW5ToIwzFofvJcS/STa6HA5gQenRUCAwEAAQJBAIq9amn00aS0h/CrjXqu
+/ThglAXJmZhOMPVn4eiu7/ROixi9sex436MaVeMqSNf7Ex9a8fRNfWss7Sqd9eWu
+RTUCIQDasvGASLqmjeffBNLTXV2A5g4t+kLVCpsEIZAycV5GswIhANEPLmax0ME/
+EO+ZJ79TJKN5yiGBRsv5yvx5UiHxajEXAiAhAol5N4EUyq6I9w1rYdhPMGpLfk7A
+IU2snfRJ6Nq2CQIgFrPsWRCkV+gOYcajD17rEqmuLrdIRexpg8N1DOSXoJ8CIGlS
+tAboUGBxTDq3ZroNism3DaMIbKPyYrAqhKov1h5V
+-----END RSA TESTING KEY-----
+`)
+
+func testingKey(s string) string { return strings.ReplaceAll(s, "TESTING KEY", "PRIVATE KEY") }