tempfork/acme: sync with tailscale/golang-x-crypto, add profiles support

This bumps go.mod to the current tailscale/golang-x-crypto, picking up its rebase onto current upstream golang.org/x/crypto and its cherry-pick of the pending upstream change https://go-review.googlesource.com/c/crypto/+/788000, which adds ACME certificate profile support: a new WithOrderProfile order option and profile discovery via the directory metadata. That change has not yet been submitted upstream and is subject to final API changes before it lands there. It then re-vendors that fork's acme package into tempfork/acme as usual (per the TestSyncedToUpstream workflow), except for upstream's pebble_test.go, which is now excluded from the sync: its TestWithPebble downloads the Pebble module from outside our go.mod, then builds and runs its binaries during tests. Profile support is needed to request LetsEncrypt IP address certificates, which require the "shortlived" profile. Updates tailscale/corp#45167 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com> Change-Id: I3f7c2a91e5d8b4a6c0e2f9d1b7a3c8e6f4d0a2b9
2026-07-25 14:56:25 -04:00 · 2026-07-20 15:48:43 +00:00
parent de0553be66
commit a84a264228
15 changed files with 377 additions and 220 deletions
--- a/flake.nix
+++ b/flake.nix
@@ -173,4 +173,4 @@
    });
  };
 }
-# nix-direnv cache busting line: sha256-XZtd1uvpeO4djloYPurifkxc6BnhRDtBfIO6lE38Usc=
+# nix-direnv cache busting line: sha256-plOIT+B2mVkUr038G4+qZt8BlUrmAH2oaVf99wK7iik=
--- a/flakehashes.json
+++ b/flakehashes.json
@@ -4,7 +4,7 @@
    "sri": "sha256-TwIaPmGVHO9ZwdaO/jDStgWGQtKa4smS3er1i5aTNTw="
  },
  "vendor": {
-    "goModSum": "sha256-EDmslq4EjYvjO5S6HwsddmmtxMqB3cVijhYBbcyBGPQ=",
-    "sri": "sha256-XZtd1uvpeO4djloYPurifkxc6BnhRDtBfIO6lE38Usc="
+    "goModSum": "sha256-nSe6X/h4KPoFvqpszhGr6u9BO7BQgL6yjpdRAGEABzE=",
+    "sri": "sha256-plOIT+B2mVkUr038G4+qZt8BlUrmAH2oaVf99wK7iik="
  }
 }
--- a/go.mod
+++ b/go.mod
@@ -103,7 +103,7 @@ require (
 	github.com/tailscale/depaware v0.0.0-20251001183927-9c2ad255ef3f
 	github.com/tailscale/gliderssh v0.3.4-0.20260716005906-1a0f895faf28
 	github.com/tailscale/goexpect v0.0.0-20210902213824-6e8c725cea41
-	github.com/tailscale/golang-x-crypto v0.0.0-20250404221719-a5573b049869
+	github.com/tailscale/golang-x-crypto v0.0.0-20260720153645-2ba0bf7866ed
 	github.com/tailscale/hujson v0.0.0-20260302212456-ecc657c15afd
 	github.com/tailscale/mkctr v0.0.0-20260107121656-ea857e3e500b
 	github.com/tailscale/netlink v1.1.1-0.20240822203006-4d49adab4de7
--- a/go.sum
+++ b/go.sum
@@ -1195,8 +1195,8 @@ github.com/tailscale/go-winio v0.0.0-20231025203758-c4f33415bf55 h1:Gzfnfk2TWrk8
 github.com/tailscale/go-winio v0.0.0-20231025203758-c4f33415bf55/go.mod h1:4k4QO+dQ3R5FofL+SanAUZe+/QfeK0+OIuwDIRu2vSg=
 github.com/tailscale/goexpect v0.0.0-20210902213824-6e8c725cea41 h1:/V2rCMMWcsjYaYO2MeovLw+ClP63OtXgCF2Y1eb8+Ns=
 github.com/tailscale/goexpect v0.0.0-20210902213824-6e8c725cea41/go.mod h1:/roCdA6gg6lQyw/Oz6gIIGu3ggJKYhF+WC/AQReE5XQ=
-github.com/tailscale/golang-x-crypto v0.0.0-20250404221719-a5573b049869 h1:SRL6irQkKGQKKLzvQP/ke/2ZuB7Py5+XuqtOgSj+iMM=
-github.com/tailscale/golang-x-crypto v0.0.0-20250404221719-a5573b049869/go.mod h1:ikbF+YT089eInTp9f2vmvy4+ZVnW5hzX1q2WknxSprQ=
+github.com/tailscale/golang-x-crypto v0.0.0-20260720153645-2ba0bf7866ed h1:uyvHhX1FQada0vVk8CSHa4tJT96EEAkTypaYz8Tq5Nc=
+github.com/tailscale/golang-x-crypto v0.0.0-20260720153645-2ba0bf7866ed/go.mod h1:NC3xRCu4UR+m4n6ix8b6oLLbHa820Y0StbOQEdWTDo0=
 github.com/tailscale/hujson v0.0.0-20260302212456-ecc657c15afd h1:Rf9uhF1+VJ7ZHqxrG8pJ6YacmHvVCmByDmGbAWCc/gA=
 github.com/tailscale/hujson v0.0.0-20260302212456-ecc657c15afd/go.mod h1:EbW0wDK/qEUYI0A5bqq0C2kF8JTQwWONmGDBbzsxxHo=
 github.com/tailscale/mkctr v0.0.0-20260107121656-ea857e3e500b h1:QKqCnmp0qHWUHySySKjpuhZANzRn7XrTVZWUuUgJ3lQ=
--- a/shell.nix
+++ b/shell.nix
@@ -16,4 +16,4 @@
 ) {
  src =  ./.;
 }).shellNix
-# nix-direnv cache busting line: sha256-XZtd1uvpeO4djloYPurifkxc6BnhRDtBfIO6lE38Usc=
+# nix-direnv cache busting line: sha256-plOIT+B2mVkUr038G4+qZt8BlUrmAH2oaVf99wK7iik=
--- a/tempfork/acme/acme.go
+++ b/tempfork/acme/acme.go
@@ -31,12 +31,11 @@
 	"crypto/x509/pkix"
 	"encoding/asn1"
 	"encoding/base64"
-	"encoding/hex"
 	"encoding/json"
-	"encoding/pem"
 	"errors"
 	"fmt"
 	"math/big"
+	"net"
 	"net/http"
 	"strings"
 	"sync"
@@ -187,10 +186,11 @@ func (c *Client) Discover(ctx context.Context) (Directory, error) {
 		KeyChange   string `json:"keyChange"`
 		RenewalInfo string `json:"renewalInfo"`
 		Meta        struct {
-			Terms        string   `json:"termsOfService"`
-			Website      string   `json:"website"`
-			CAA          []string `json:"caaIdentities"`
-			ExternalAcct bool     `json:"externalAccountRequired"`
+			Terms        string            `json:"termsOfService"`
+			Website      string            `json:"website"`
+			CAA          []string          `json:"caaIdentities"`
+			ExternalAcct bool              `json:"externalAccountRequired"`
+			Profiles     map[string]string `json:"profiles"`
 		}
 	}
 	if err := json.NewDecoder(res.Body).Decode(&v); err != nil {
@@ -211,6 +211,7 @@ func (c *Client) Discover(ctx context.Context) (Directory, error) {
 		Website:                 v.Meta.Website,
 		CAA:                     v.Meta.CAA,
 		ExternalAccountRequired: v.Meta.ExternalAcct,
+		Profiles:                v.Meta.Profiles,
 	}
 	return *c.dir, nil
 }
@@ -397,6 +398,10 @@ func (c *Client) authorize(ctx context.Context, typ, val string) (*Authorization
 	if _, err := c.Discover(ctx); err != nil {
 		return nil, err
 	}
+	if c.dir.AuthzURL == "" {
+		// Pre-Authorization is unsupported
+		return nil, errPreAuthorizationNotSupported
+	}

 	type authzID struct {
 		Type  string `json:"type"`
@@ -511,7 +516,7 @@ func (c *Client) WaitAuthorization(ctx context.Context, url string) (*Authorizat
 		// while waiting for a final authorization status.
 		d := retryAfter(res.Header.Get("Retry-After"))
 		if d == 0 {
-			// Given that the fastest challenges TLS-SNI and HTTP-01
+			// Given that the fastest challenges TLS-ALPN and HTTP-01
 			// require a CA to make at least 1 network round trip
 			// and most likely persist a challenge state,
 			// this default delay seems reasonable.
@@ -612,50 +617,28 @@ func (c *Client) HTTP01ChallengePath(token string) string {
 }

 // TLSSNI01ChallengeCert creates a certificate for TLS-SNI-01 challenge response.
+// Always returns an error.
 //
-// Deprecated: This challenge type is unused in both draft-02 and RFC versions of the ACME spec.
-func (c *Client) TLSSNI01ChallengeCert(token string, opt ...CertOption) (cert tls.Certificate, name string, err error) {
-	ka, err := keyAuth(c.Key.Public(), token)
-	if err != nil {
-		return tls.Certificate{}, "", err
-	}
-	b := sha256.Sum256([]byte(ka))
-	h := hex.EncodeToString(b[:])
-	name = fmt.Sprintf("%s.%s.acme.invalid", h[:32], h[32:])
-	cert, err = tlsChallengeCert([]string{name}, opt)
-	if err != nil {
-		return tls.Certificate{}, "", err
-	}
-	return cert, name, nil
+// Deprecated: This challenge type was only present in pre-standardized ACME
+// protocol drafts and is insecure for use in shared hosting environments.
+func (c *Client) TLSSNI01ChallengeCert(token string, opt ...CertOption) (tls.Certificate, string, error) {
+	return tls.Certificate{}, "", errPreRFC
 }

 // TLSSNI02ChallengeCert creates a certificate for TLS-SNI-02 challenge response.
+// Always returns an error.
 //
-// Deprecated: This challenge type is unused in both draft-02 and RFC versions of the ACME spec.
-func (c *Client) TLSSNI02ChallengeCert(token string, opt ...CertOption) (cert tls.Certificate, name string, err error) {
-	b := sha256.Sum256([]byte(token))
-	h := hex.EncodeToString(b[:])
-	sanA := fmt.Sprintf("%s.%s.token.acme.invalid", h[:32], h[32:])
-
-	ka, err := keyAuth(c.Key.Public(), token)
-	if err != nil {
-		return tls.Certificate{}, "", err
-	}
-	b = sha256.Sum256([]byte(ka))
-	h = hex.EncodeToString(b[:])
-	sanB := fmt.Sprintf("%s.%s.ka.acme.invalid", h[:32], h[32:])
-
-	cert, err = tlsChallengeCert([]string{sanA, sanB}, opt)
-	if err != nil {
-		return tls.Certificate{}, "", err
-	}
-	return cert, sanA, nil
+// Deprecated: This challenge type was only present in pre-standardized ACME
+// protocol drafts and is insecure for use in shared hosting environments.
+func (c *Client) TLSSNI02ChallengeCert(token string, opt ...CertOption) (tls.Certificate, string, error) {
+	return tls.Certificate{}, "", errPreRFC
 }

 // TLSALPN01ChallengeCert creates a certificate for TLS-ALPN-01 challenge response.
 // Servers can present the certificate to validate the challenge and prove control
-// over a domain name. For more details on TLS-ALPN-01 see
-// https://tools.ietf.org/html/draft-shoemaker-acme-tls-alpn-00#section-3
+// over an identifier (either a DNS name or the textual form of an IPv4 or IPv6
+// address). For more details on TLS-ALPN-01 see
+// https://www.rfc-editor.org/rfc/rfc8737 and https://www.rfc-editor.org/rfc/rfc8738
 //
 // The token argument is a Challenge.Token value.
 // If a WithKey option is provided, its private part signs the returned cert,
@@ -663,9 +646,13 @@ func (c *Client) TLSSNI02ChallengeCert(token string, opt ...CertOption) (cert tl
 // If no WithKey option is provided, a new ECDSA key is generated using P-256 curve.
 //
 // The returned certificate is valid for the next 24 hours and must be presented only when
-// the server name in the TLS ClientHello matches the domain, and the special acme-tls/1 ALPN protocol
+// the server name in the TLS ClientHello matches the identifier, and the special acme-tls/1 ALPN protocol
 // has been specified.
-func (c *Client) TLSALPN01ChallengeCert(token, domain string, opt ...CertOption) (cert tls.Certificate, err error) {
+//
+// Validation requests for IP address identifiers will use the reverse DNS form in the server name
+// in the TLS ClientHello since the SNI extension is not supported for IP addresses.
+// See RFC 8738 Section 6 for more information.
+func (c *Client) TLSALPN01ChallengeCert(token, identifier string, opt ...CertOption) (cert tls.Certificate, err error) {
 	ka, err := keyAuth(c.Key.Public(), token)
 	if err != nil {
 		return tls.Certificate{}, err
@@ -695,7 +682,7 @@ func (c *Client) TLSALPN01ChallengeCert(token, domain string, opt ...CertOption)
 	}
 	tmpl.ExtraExtensions = append(tmpl.ExtraExtensions, acmeExtension)
 	newOpt = append(newOpt, WithTemplate(tmpl))
-	return tlsChallengeCert([]string{domain}, newOpt)
+	return tlsChallengeCert(identifier, newOpt)
 }

 // popNonce returns a nonce value previously stored with c.addNonce
@@ -749,7 +736,7 @@ func (c *Client) addNonce(h http.Header) {
 }

 func (c *Client) fetchNonce(ctx context.Context, url string) (string, error) {
-	r, err := http.NewRequest("HEAD", url, nil)
+	r, err := http.NewRequestWithContext(ctx, "HEAD", url, nil)
 	if err != nil {
 		return "", err
 	}
@@ -813,11 +800,15 @@ func defaultTLSChallengeCertTemplate() *x509.Certificate {
 	}
 }

-// tlsChallengeCert creates a temporary certificate for TLS-SNI challenges
-// with the given SANs and auto-generated public/private key pair.
-// The Subject Common Name is set to the first SAN to aid debugging.
+// tlsChallengeCert creates a temporary certificate for TLS-ALPN challenges
+// for the given identifier, using an auto-generated public/private key pair.
+//
+// If the provided identifier is a domain name, it will be used as a DNS type SAN and for the
+// subject common name. If the provided identifier is an IP address it will be used as an IP type
+// SAN.
+//
 // To create a cert with a custom key pair, specify WithKey option.
-func tlsChallengeCert(san []string, opt []CertOption) (tls.Certificate, error) {
+func tlsChallengeCert(identifier string, opt []CertOption) (tls.Certificate, error) {
 	var key crypto.Signer
 	tmpl := defaultTLSChallengeCertTemplate()
 	for _, o := range opt {
@@ -841,9 +832,12 @@ func tlsChallengeCert(san []string, opt []CertOption) (tls.Certificate, error) {
 			return tls.Certificate{}, err
 		}
 	}
-	tmpl.DNSNames = san
-	if len(san) > 0 {
-		tmpl.Subject.CommonName = san[0]
+
+	if ip := net.ParseIP(identifier); ip != nil {
+		tmpl.IPAddresses = []net.IP{ip}
+	} else {
+		tmpl.DNSNames = []string{identifier}
+		tmpl.Subject.CommonName = identifier
 	}

 	der, err := x509.CreateCertificate(rand.Reader, tmpl, tmpl, key.Public(), key)
@@ -856,11 +850,5 @@ func tlsChallengeCert(san []string, opt []CertOption) (tls.Certificate, error) {
 	}, nil
 }

-// encodePEM returns b encoded as PEM with block of type typ.
-func encodePEM(typ string, b []byte) []byte {
-	pb := &pem.Block{Type: typ, Bytes: b}
-	return pem.EncodeToMemory(pb)
-}
-
 // timeNow is time.Now, except in tests which can mess with it.
 var timeNow = time.Now
--- a/tempfork/acme/acme_test.go
+++ b/tempfork/acme/acme_test.go
@@ -9,13 +9,13 @@
 	"context"
 	"crypto/rand"
 	"crypto/rsa"
-	"crypto/tls"
 	"crypto/x509"
 	"crypto/x509/pkix"
 	"encoding/base64"
 	"encoding/hex"
 	"encoding/json"
 	"encoding/pem"
+	"errors"
 	"fmt"
 	"io"
 	"math/big"
@@ -23,7 +23,6 @@
 	"net/http/httptest"
 	"net/url"
 	"reflect"
-	"sort"
 	"strings"
 	"testing"
 	"time"
@@ -267,6 +266,57 @@ func TestAuthorizeValid(t *testing.T) {
 	}
 }

+func TestAuthorizeUnsupported(t *testing.T) {
+	const (
+		nonce       = "https://example.com/acme/new-nonce"
+		reg         = "https://example.com/acme/new-acct"
+		order       = "https://example.com/acme/new-order"
+		revoke      = "https://example.com/acme/revoke-cert"
+		keychange   = "https://example.com/acme/key-change"
+		metaTerms   = "https://example.com/acme/terms/2017-5-30"
+		metaWebsite = "https://www.example.com/"
+		metaCAA     = "example.com"
+	)
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Replay-Nonce", "nonce")
+		if r.Method == http.MethodHead {
+			return
+		}
+		switch r.URL.Path {
+		case "/": // Directory
+			w.Header().Set("Content-Type", "application/json")
+			fmt.Fprintf(w, `{
+                "newNonce": %q,
+                "newAccount": %q,
+                "newOrder": %q,
+                "revokeCert": %q,
+                "keyChange": %q,
+                "meta": {
+                    "termsOfService": %q,
+                    "website": %q,
+                    "caaIdentities": [%q],
+                    "externalAccountRequired": true
+                }
+            }`, nonce, reg, order, revoke, keychange, metaTerms, metaWebsite, metaCAA)
+			w.WriteHeader(http.StatusOK)
+		case "/acme/new-authz":
+			w.WriteHeader(http.StatusBadRequest)
+		}
+	}))
+	defer ts.Close()
+	client := &Client{Key: testKey, DirectoryURL: ts.URL}
+	dir, err := client.Discover(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if dir.AuthzURL != "" {
+		t.Fatalf("expected AuthzURL to be empty, got %q", dir.AuthzURL)
+	}
+	if _, err := client.Authorize(context.Background(), "example.com"); !errors.Is(err, errPreAuthorizationNotSupported) {
+		t.Errorf("expected err to indicate pre-authorization is unsupported, got %+v", err)
+	}
+}
+
 func TestWaitAuthorization(t *testing.T) {
 	t.Run("wait loop", func(t *testing.T) {
 		var count int
@@ -755,71 +805,6 @@ func TestLinkHeader(t *testing.T) {
 	}
 }

-func TestTLSSNI01ChallengeCert(t *testing.T) {
-	const (
-		token = "evaGxfADs6pSRb2LAv9IZf17Dt3juxGJ-PCt92wr-oA"
-		// echo -n <token.testKeyECThumbprint> | shasum -a 256
-		san = "dbbd5eefe7b4d06eb9d1d9f5acb4c7cd.a27d320e4b30332f0b6cb441734ad7b0.acme.invalid"
-	)
-
-	tlscert, name, err := newTestClient().TLSSNI01ChallengeCert(token)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if n := len(tlscert.Certificate); n != 1 {
-		t.Fatalf("len(tlscert.Certificate) = %d; want 1", n)
-	}
-	cert, err := x509.ParseCertificate(tlscert.Certificate[0])
-	if err != nil {
-		t.Fatal(err)
-	}
-	if len(cert.DNSNames) != 1 || cert.DNSNames[0] != san {
-		t.Fatalf("cert.DNSNames = %v; want %q", cert.DNSNames, san)
-	}
-	if cert.DNSNames[0] != name {
-		t.Errorf("cert.DNSNames[0] != name: %q vs %q", cert.DNSNames[0], name)
-	}
-	if cn := cert.Subject.CommonName; cn != san {
-		t.Errorf("cert.Subject.CommonName = %q; want %q", cn, san)
-	}
-}
-
-func TestTLSSNI02ChallengeCert(t *testing.T) {
-	const (
-		token = "evaGxfADs6pSRb2LAv9IZf17Dt3juxGJ-PCt92wr-oA"
-		// echo -n evaGxfADs6pSRb2LAv9IZf17Dt3juxGJ-PCt92wr-oA | shasum -a 256
-		sanA = "7ea0aaa69214e71e02cebb18bb867736.09b730209baabf60e43d4999979ff139.token.acme.invalid"
-		// echo -n <token.testKeyECThumbprint> | shasum -a 256
-		sanB = "dbbd5eefe7b4d06eb9d1d9f5acb4c7cd.a27d320e4b30332f0b6cb441734ad7b0.ka.acme.invalid"
-	)
-
-	tlscert, name, err := newTestClient().TLSSNI02ChallengeCert(token)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if n := len(tlscert.Certificate); n != 1 {
-		t.Fatalf("len(tlscert.Certificate) = %d; want 1", n)
-	}
-	cert, err := x509.ParseCertificate(tlscert.Certificate[0])
-	if err != nil {
-		t.Fatal(err)
-	}
-	names := []string{sanA, sanB}
-	if !reflect.DeepEqual(cert.DNSNames, names) {
-		t.Fatalf("cert.DNSNames = %v;\nwant %v", cert.DNSNames, names)
-	}
-	sort.Strings(cert.DNSNames)
-	i := sort.SearchStrings(cert.DNSNames, name)
-	if i >= len(cert.DNSNames) || cert.DNSNames[i] != name {
-		t.Errorf("%v doesn't have %q", cert.DNSNames, name)
-	}
-	if cn := cert.Subject.CommonName; cn != sanA {
-		t.Errorf("CommonName = %q; want %q", cn, sanA)
-	}
-}
-
 func TestTLSALPN01ChallengeCert(t *testing.T) {
 	const (
 		token   = "evaGxfADs6pSRb2LAv9IZf17Dt3juxGJ-PCt92wr-oA"
@@ -876,6 +861,7 @@ func TestTLSChallengeCertOpt(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	domain := "example.com"
 	tmpl := &x509.Certificate{
 		SerialNumber: big.NewInt(2),
 		Subject:      pkix.Name{Organization: []string{"Test"}},
@@ -884,52 +870,43 @@ func TestTLSChallengeCertOpt(t *testing.T) {
 	opts := []CertOption{WithKey(key), WithTemplate(tmpl)}

 	client := newTestClient()
-	cert1, _, err := client.TLSSNI01ChallengeCert("token", opts...)
-	if err != nil {
-		t.Fatal(err)
-	}
-	cert2, _, err := client.TLSSNI02ChallengeCert("token", opts...)
+	cert, err := client.TLSALPN01ChallengeCert("token", domain, opts...)
 	if err != nil {
 		t.Fatal(err)
 	}

-	for i, tlscert := range []tls.Certificate{cert1, cert2} {
-		// verify generated cert private key
-		tlskey, ok := tlscert.PrivateKey.(*rsa.PrivateKey)
-		if !ok {
-			t.Errorf("%d: tlscert.PrivateKey is %T; want *rsa.PrivateKey", i, tlscert.PrivateKey)
-			continue
-		}
-		if tlskey.D.Cmp(key.D) != 0 {
-			t.Errorf("%d: tlskey.D = %v; want %v", i, tlskey.D, key.D)
-		}
-		// verify generated cert public key
-		x509Cert, err := x509.ParseCertificate(tlscert.Certificate[0])
-		if err != nil {
-			t.Errorf("%d: %v", i, err)
-			continue
-		}
-		tlspub, ok := x509Cert.PublicKey.(*rsa.PublicKey)
-		if !ok {
-			t.Errorf("%d: x509Cert.PublicKey is %T; want *rsa.PublicKey", i, x509Cert.PublicKey)
-			continue
-		}
-		if tlspub.N.Cmp(key.N) != 0 {
-			t.Errorf("%d: tlspub.N = %v; want %v", i, tlspub.N, key.N)
-		}
-		// verify template option
-		sn := big.NewInt(2)
-		if x509Cert.SerialNumber.Cmp(sn) != 0 {
-			t.Errorf("%d: SerialNumber = %v; want %v", i, x509Cert.SerialNumber, sn)
-		}
-		org := []string{"Test"}
-		if !reflect.DeepEqual(x509Cert.Subject.Organization, org) {
-			t.Errorf("%d: Subject.Organization = %+v; want %+v", i, x509Cert.Subject.Organization, org)
-		}
-		for _, v := range x509Cert.DNSNames {
-			if !strings.HasSuffix(v, ".acme.invalid") {
-				t.Errorf("%d: invalid DNSNames element: %q", i, v)
-			}
+	// verify generated cert private key
+	tlskey, ok := cert.PrivateKey.(*rsa.PrivateKey)
+	if !ok {
+		t.Fatalf("tlscert.PrivateKey is %T; want *rsa.PrivateKey", cert.PrivateKey)
+	}
+	if tlskey.D.Cmp(key.D) != 0 {
+		t.Errorf("tlskey.D = %v; want %v", tlskey.D, key.D)
+	}
+	// verify generated cert public key
+	x509Cert, err := x509.ParseCertificate(cert.Certificate[0])
+	if err != nil {
+		t.Fatal(err)
+	}
+	tlspub, ok := x509Cert.PublicKey.(*rsa.PublicKey)
+	if !ok {
+		t.Fatalf("x509Cert.PublicKey is %T; want *rsa.PublicKey", x509Cert.PublicKey)
+	}
+	if tlspub.N.Cmp(key.N) != 0 {
+		t.Errorf("tlspub.N = %v; want %v", tlspub.N, key.N)
+	}
+	// verify template option
+	sn := big.NewInt(2)
+	if x509Cert.SerialNumber.Cmp(sn) != 0 {
+		t.Errorf("SerialNumber = %v; want %v", x509Cert.SerialNumber, sn)
+	}
+	org := []string{"Test"}
+	if !reflect.DeepEqual(x509Cert.Subject.Organization, org) {
+		t.Errorf("Subject.Organization = %+v; want %+v", x509Cert.Subject.Organization, org)
+	}
+	for _, v := range x509Cert.DNSNames {
+		if v != domain {
+			t.Errorf("invalid DNSNames element: %q", v)
 		}
 	}
 }
--- a/tempfork/acme/http.go
+++ b/tempfork/acme/http.go
@@ -66,7 +66,7 @@ func (c *Client) retryTimer() *retryTimer {
 // The n argument is always bounded between 1 and 30.
 // The returned value is always greater than 0.
 func defaultBackoff(n int, r *http.Request, res *http.Response) time.Duration {
-	const max = 10 * time.Second
+	const maxVal = 10 * time.Second
 	var jitter time.Duration
 	if x, err := rand.Int(rand.Reader, big.NewInt(1000)); err == nil {
 		// Set the minimum to 1ms to avoid a case where
@@ -86,10 +86,7 @@ func defaultBackoff(n int, r *http.Request, res *http.Response) time.Duration {
 		n = 30
 	}
 	d := time.Duration(1<<uint(n-1))*time.Second + jitter
-	if d > max {
-		return max
-	}
-	return d
+	return min(d, maxVal)
 }

 // retryAfter parses a Retry-After HTTP header value,
@@ -131,7 +128,7 @@ func wantStatus(codes ...int) resOkay {
 func (c *Client) get(ctx context.Context, url string, ok resOkay) (*http.Response, error) {
 	retry := c.retryTimer()
 	for {
-		req, err := http.NewRequest("GET", url, nil)
+		req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
 		if err != nil {
 			return nil, err
 		}
@@ -231,7 +228,7 @@ func (c *Client) postNoRetry(ctx context.Context, key crypto.Signer, url string,
 	if err != nil {
 		return nil, nil, err
 	}
-	req, err := http.NewRequest("POST", url, bytes.NewReader(b))
+	req, err := http.NewRequestWithContext(ctx, "POST", url, bytes.NewReader(b))
 	if err != nil {
 		return nil, nil, err
 	}
--- a/tempfork/acme/jws.go
+++ b/tempfork/acme/jws.go
@@ -92,7 +92,7 @@ func jwsEncodeJSON(claimset interface{}, key crypto.Signer, kid KeyID, nonce, ur
 	if err != nil {
 		return nil, err
 	}
-	phead := base64.RawURLEncoding.EncodeToString([]byte(phJSON))
+	phead := base64.RawURLEncoding.EncodeToString(phJSON)
 	var payload string
 	if val, ok := claimset.(string); ok {
 		payload = val
--- a/tempfork/acme/rfc8555.go
+++ b/tempfork/acme/rfc8555.go
@@ -54,6 +54,9 @@ func (c *Client) registerRFC(ctx context.Context, acct *Account, prompt func(tos
 		Contact: acct.Contact,
 	}
 	if c.dir.Terms != "" {
+		if prompt == nil {
+			return nil, errors.New("acme: missing Manager.Prompt to accept server's terms of service")
+		}
 		req.TermsAgreed = prompt(c.dir.Terms)
 	}

@@ -207,6 +210,7 @@ func (c *Client) AuthorizeOrder(ctx context.Context, id []AuthzID, opt ...OrderO
 		NotBefore   string        `json:"notBefore,omitempty"`
 		NotAfter    string        `json:"notAfter,omitempty"`
 		Replaces    string        `json:"replaces,omitempty"`
+		Profile     string        `json:"profile,omitempty"`
 	}{}
 	for _, v := range id {
 		req.Identifiers = append(req.Identifiers, wireAuthzID{
@@ -228,6 +232,15 @@ func (c *Client) AuthorizeOrder(ctx context.Context, id []AuthzID, opt ...OrderO
 				return nil, fmt.Errorf("failed to parse certificate being replaced: %w", err)
 			}
 			req.Replaces = certRenewalIdentifier(cert)
+		case orderProfileOpt:
+			if !dir.Profiles.isSupported() {
+				return nil, ErrCADoesNotSupportProfiles
+			}
+			profileName := string(o)
+			if !dir.Profiles.Has(profileName) {
+				return nil, fmt.Errorf("%w %s", ErrProfileNotInSetOfSupportedProfiles, profileName)
+			}
+			req.Profile = profileName
 		default:
 			// Package's fault if we let this happen.
 			panic(fmt.Sprintf("unsupported order option type %T", o))
@@ -242,7 +255,7 @@ func (c *Client) AuthorizeOrder(ctx context.Context, id []AuthzID, opt ...OrderO
 	return responseOrder(res)
 }

-// GetOrder retrives an order identified by the given URL.
+// GetOrder retrieves an order identified by the given URL.
 // For orders created with AuthorizeOrder, the url value is Order.URI.
 //
 // If a caller needs to poll an order until its status is final,
@@ -282,7 +295,7 @@ func (c *Client) WaitOrder(ctx context.Context, url string) (*Order, error) {
 		case err != nil:
 			// Skip and retry.
 		case o.Status == StatusInvalid:
-			return nil, &OrderError{OrderURL: o.URI, Status: o.Status}
+			return nil, &OrderError{OrderURL: o.URI, Status: o.Status, Problem: o.Error}
 		case o.Status == StatusReady || o.Status == StatusValid:
 			return o, nil
 		}
@@ -379,7 +392,7 @@ func (c *Client) CreateOrderCert(ctx context.Context, url string, csr []byte, bu
 	}
 	// The only acceptable status post finalize and WaitOrder is "valid".
 	if o.Status != StatusValid {
-		return nil, "", &OrderError{OrderURL: o.URI, Status: o.Status}
+		return nil, "", &OrderError{OrderURL: o.URI, Status: o.Status, Problem: o.Error}
 	}
 	crt, err := c.fetchCertRFC(ctx, o.CertURL, bundle)
 	return crt, o.CertURL, err
--- a/tempfork/acme/rfc8555_test.go
+++ b/tempfork/acme/rfc8555_test.go
@@ -99,6 +99,61 @@ func TestRFC_Discover(t *testing.T) {
 	if !dir.ExternalAccountRequired {
 		t.Error("dir.Meta.ExternalAccountRequired is false")
 	}
+	if dir.Profiles != nil {
+		t.Errorf("dir.Profiles is expected to be nil, got %+v", dir.Profiles)
+	}
+}
+
+func TestDiscover_WithProfiles(t *testing.T) {
+	const (
+		nonce       = "https://example.com/acme/new-nonce"
+		reg         = "https://example.com/acme/new-acct"
+		order       = "https://example.com/acme/new-order"
+		authz       = "https://example.com/acme/new-authz"
+		revoke      = "https://example.com/acme/revoke-cert"
+		keychange   = "https://example.com/acme/key-change"
+		metaTerms   = "https://example.com/acme/terms/2017-5-30"
+		metaWebsite = "https://www.example.com/"
+		metaCAA     = "example.com"
+	)
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprintf(w, `{
+			"newNonce": %q,
+			"newAccount": %q,
+			"newOrder": %q,
+			"newAuthz": %q,
+			"revokeCert": %q,
+			"keyChange": %q,
+			"meta": {
+				"termsOfService": %q,
+				"website": %q,
+				"caaIdentities": [%q],
+				"externalAccountRequired": true,
+                "profiles": {
+                    "default": "Your favorite default profile",
+                    "tlsserver": "New and improved",
+                    "client": "For all your mutual TLS needs"
+                }
+			}
+		}`, nonce, reg, order, authz, revoke, keychange, metaTerms, metaWebsite, metaCAA)
+	}))
+	defer ts.Close()
+	c := &Client{DirectoryURL: ts.URL}
+	dir, err := c.Discover(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	expected := Profiles(map[string]string{"default": "Your favorite default profile", "tlsserver": "New and improved", "client": "For all your mutual TLS needs"})
+	if dir.Profiles == nil {
+		t.Errorf("expected directory to be %+v; got nil", expected)
+	}
+
+	for key, value := range dir.Profiles {
+		if expValue := expected.GetDescription(key); value != expValue {
+			t.Errorf("expected key %+q to have description %+q; got %+q", key, expected, value)
+		}
+	}
 }

 func TestRFC_popNonce(t *testing.T) {
@@ -247,6 +302,27 @@ func (s *acmeServer) start() {
 			return
 		}

+		if r.URL.Path == "/directory-with-profiles" {
+			fmt.Fprintf(w, `{
+				"newNonce": %q,
+				"newAccount": %q,
+				"newOrder": %q,
+				"newAuthz": %q,
+				"revokeCert": %q,
+				"keyChange": %q,
+                "meta": {"termsOfService": %q, "profiles": {"default": "Default", "server": "Server", "client": "Client"}}
+				}`,
+				s.url("/acme/new-nonce"),
+				s.url("/acme/new-account"),
+				s.url("/acme/new-order"),
+				s.url("/acme/new-authz"),
+				s.url("/acme/revoke-cert"),
+				s.url("/acme/key-change"),
+				s.url("/terms"),
+			)
+			return
+		}
+
 		// All other responses contain a nonce value unconditionally.
 		w.Header().Set("Replay-Nonce", s.nonce())
 		if r.URL.Path == "/acme/new-nonce" {
@@ -795,6 +871,51 @@ func TestRFC_AuthorizeOrder(t *testing.T) {
 	}
 }

+func TestRFC_AuthorizeOrder_WithOrderProfile(t *testing.T) {
+	s := newACMEServer()
+	s.handle("/acme/new-account", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Location", s.url("/accounts/1"))
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte(`{"status": "valid"}`))
+	})
+	s.handle("/acme/new-order", func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Location", s.url("/orders/1"))
+		w.WriteHeader(http.StatusCreated)
+		fmt.Fprintf(w, `{
+			"status": "pending",
+			"expires": "2019-09-01T00:00:00Z",
+			"notBefore": "2019-08-31T00:00:00Z",
+			"notAfter": "2019-09-02T00:00:00Z",
+			"identifiers": [{"type":"dns", "value":"example.org"}],
+			"authorizations": [%q]
+		}`, s.url("/authz/1"))
+	})
+	s.start()
+	defer s.close()
+
+	cl := &Client{Key: testKeyEC, DirectoryURL: s.url("/directory-with-profiles")}
+	o, err := cl.AuthorizeOrder(context.Background(), DomainIDs("example.org"),
+		WithOrderNotBefore(time.Date(2019, 8, 31, 0, 0, 0, 0, time.UTC)),
+		WithOrderNotAfter(time.Date(2019, 9, 2, 0, 0, 0, 0, time.UTC)),
+		WithOrderProfile("server"),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+	okOrder := &Order{
+		URI:         s.url("/orders/1"),
+		Status:      StatusPending,
+		Expires:     time.Date(2019, 9, 1, 0, 0, 0, 0, time.UTC),
+		NotBefore:   time.Date(2019, 8, 31, 0, 0, 0, 0, time.UTC),
+		NotAfter:    time.Date(2019, 9, 2, 0, 0, 0, 0, time.UTC),
+		Identifiers: []AuthzID{{Type: "dns", Value: "example.org"}},
+		AuthzURLs:   []string{s.url("/authz/1")},
+	}
+	if !reflect.DeepEqual(o, okOrder) {
+		t.Errorf("AuthorizeOrder = %+v; want %+v", o, okOrder)
+	}
+}
+
 func TestRFC_GetOrder(t *testing.T) {
 	s := newACMEServer()
 	s.handle("/acme/new-account", func(w http.ResponseWriter, r *http.Request) {
@@ -892,11 +1013,17 @@ func TestRFC_WaitOrderError(t *testing.T) {
 	s.handle("/orders/1", func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Location", s.url("/orders/1"))
 		w.WriteHeader(http.StatusOK)
-		s := StatusPending
 		if count > 0 {
-			s = StatusInvalid
+			// https://www.rfc-editor.org/rfc/rfc8555#section-7.3.3
+			errorData := `{
+				"type": "urn:ietf:params:acme:error:userActionRequired",
+				"detail": "Terms of service have changed",
+				"instance": "https://example.com/acme/agreement/?token=W8Ih3PswD-8"
+			}`
+			fmt.Fprintf(w, `{"status": %q, "error": %s}`, StatusInvalid, errorData)
+		} else {
+			fmt.Fprintf(w, `{"status": %q}`, StatusPending)
 		}
-		fmt.Fprintf(w, `{"status": %q}`, s)
 		count++
 	})
 	s.start()
@@ -917,6 +1044,13 @@ func TestRFC_WaitOrderError(t *testing.T) {
 	if e.Status != StatusInvalid {
 		t.Errorf("e.Status = %q; want %q", e.Status, StatusInvalid)
 	}
+	if e.Problem == nil {
+		t.Errorf("e.Problem = nil")
+	}
+	expectedProbType := "urn:ietf:params:acme:error:userActionRequired"
+	if e.Problem.ProblemType != expectedProbType {
+		t.Errorf("e.Problem.ProblemType = %q; want %q", e.Problem.ProblemType, expectedProbType)
+	}
 }

 func TestRFC_CreateOrderCert(t *testing.T) {
--- a/tempfork/acme/sync_to_upstream_test.go
+++ b/tempfork/acme/sync_to_upstream_test.go
@@ -45,7 +45,14 @@ func TestSyncedToUpstream(t *testing.T) {
 		}
 		for _, de := range ents {
 			name := de.Name()
-			if name == "sync_to_upstream_test.go" {
+			switch name {
+			case "sync_to_upstream_test.go":
+				continue
+			case "pebble_test.go":
+				// We don't vendor upstream's pebble_test.go: its
+				// TestWithPebble downloads the Pebble module from
+				// outside our go.mod, then builds and runs its
+				// binaries during tests.
 				continue
 			}
 			if !strings.HasSuffix(name, ".go") {
--- a/tempfork/acme/types.go
+++ b/tempfork/acme/types.go
@@ -56,6 +56,19 @@

 	// ErrNoAccount indicates that the Client's key has not been registered with the CA.
 	ErrNoAccount = errors.New("acme: account does not exist")
+
+	// errPreAuthorizationNotSupported indicates that the server does not
+	// support pre-authorization of identifiers.
+	errPreAuthorizationNotSupported = errors.New("acme: pre-authorization is not supported")
+
+	// ErrCADoesNotSupportProfiles indicates that [WithOrderProfile] was
+	// included with a CA that does not advertise support for profiles in
+	// their directory.
+	ErrCADoesNotSupportProfiles = errors.New("acme: certificate authority does not support profiles")
+
+	// ErrProfileNotInSetOfSupportedProfiles indicates that the profile
+	// specified with [WithOrderProfile} is not one supported by the CA
+	ErrProfileNotInSetOfSupportedProfiles = errors.New("acme: certificate authority does not advertise a profile with name")
 )

 // A Subproblem describes an ACME subproblem as reported in an Error.
@@ -150,17 +163,24 @@ func (a *AuthorizationError) Error() string {

 // OrderError is returned from Client's order related methods.
 // It indicates the order is unusable and the clients should start over with
-// AuthorizeOrder.
+// AuthorizeOrder. A Problem description may be provided with details on
+// what caused the order to become unusable.
 //
 // The clients can still fetch the order object from CA using GetOrder
 // to inspect its state.
 type OrderError struct {
 	OrderURL string
 	Status   string
+	// Problem is the error that occurred while processing the order.
+	Problem *Error
 }

 func (oe *OrderError) Error() string {
-	return fmt.Sprintf("acme: order %s status: %s", oe.OrderURL, oe.Status)
+	str := fmt.Sprintf("acme: order %s status: %s", oe.OrderURL, oe.Status)
+	if oe.Problem != nil {
+		str += fmt.Sprintf("; problem: %s", oe.Problem)
+	}
+	return str
 }

 // RateLimit reports whether err represents a rate limit error and
@@ -308,6 +328,10 @@ type Directory struct {
 	// ExternalAccountRequired indicates that the CA requires for all account-related
 	// requests to include external account binding information.
 	ExternalAccountRequired bool
+
+	// Profiles indicates that the CA supports specifying a profile for an
+	// order. See also [WithOrderNotAfter].
+	Profiles Profiles
 }

 // Order represents a client's request for a certificate.
@@ -383,6 +407,15 @@ func WithOrderNotAfter(t time.Time) OrderOption {
 	return orderNotAfterOpt(t)
 }

+// WithOrderProfile sets an order's Profile field for servers which support
+// profiles.
+// See also:
+// * https://datatracker.ietf.org/doc/draft-aaron-acme-profiles/
+// * https://letsencrypt.org/docs/profiles/
+func WithOrderProfile(name string) OrderOption {
+	return orderProfileOpt(name)
+}
+
 type orderNotBeforeOpt time.Time

 func (orderNotBeforeOpt) privateOrderOpt() {}
@@ -415,6 +448,10 @@ func WithOrderReplacesCertDER(der []byte) OrderOption {

 func (orderReplacesCertDER) privateOrderOpt() {}

+type orderProfileOpt string
+
+func (orderProfileOpt) privateOrderOpt() {}
+
 // Authorization encodes an authorization response.
 type Authorization struct {
 	// URI uniquely identifies a authorization.
@@ -643,7 +680,7 @@ func (*certOptKey) privateCertOpt() {}
 //
 // In TLS ChallengeCert methods, the template is also used as parent,
 // resulting in a self-signed certificate.
-// The DNSNames field of t is always overwritten for tls-sni challenge certs.
+// The DNSNames or IPAddresses fields of t are always overwritten for tls-alpn challenge certs.
 func WithTemplate(t *x509.Certificate) CertOption {
 	return (*certOptTemplate)(t)
 }
@@ -665,3 +702,18 @@ type RenewalInfo struct {
 	SuggestedWindow RenewalInfoWindow `json:"suggestedWindow"`
 	ExplanationURL  string            `json:"explanationURL"`
 }
+
+type Profiles map[string]string
+
+func (ps Profiles) isSupported() bool {
+	return len(ps) > 0
+}
+
+func (ps Profiles) GetDescription(name string) string {
+	return ps[name]
+}
+
+func (ps Profiles) Has(name string) bool {
+	_, ok := ps[name]
+	return ok
+}
--- a/tempfork/acme/types_test.go
+++ b/tempfork/acme/types_test.go
@@ -217,3 +217,19 @@ func TestErrorStringerWithSubproblems(t *testing.T) {
 		t.Errorf("Unexpected error string: wanted %q, got %q", expectedStr, err.Error())
 	}
 }
+
+func TestOrderErrorProblem(t *testing.T) {
+	oe := &OrderError{
+		OrderURL: "url",
+		Status:   "invalid",
+		Problem: &Error{
+			StatusCode:  400,
+			ProblemType: "type",
+			Detail:      "detail",
+		},
+	}
+	want := "acme: order url status: invalid; problem: 400 type: detail"
+	if got := oe.Error(); got != want {
+		t.Errorf("oe.Error() = %q, want %q", got, want)
+	}
+}
--- a/tempfork/acme/version_go112.go
+++ b/tempfork/acme/version_go112.go
@@ -1,27 +0,0 @@
-// Copyright 2019 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build go1.12
-
-package acme
-
-import "runtime/debug"
-
-func init() {
-	// Set packageVersion if the binary was built in modules mode and x/crypto
-	// was not replaced with a different module.
-	info, ok := debug.ReadBuildInfo()
-	if !ok {
-		return
-	}
-	for _, m := range info.Deps {
-		if m.Path != "golang.org/x/crypto" {
-			continue
-		}
-		if m.Replace == nil {
-			packageVersion = m.Version
-		}
-		break
-	}
-}