Merge branch 'master' into hs/acme-eab

acme/order.go

@@ -200,6 +200,10 @@ func (o *Order) sans(csr *x509.CertificateRequest) ([]x509util.SubjectAlternativ
 
 	var sans []x509util.SubjectAlternativeName
 
+	if len(csr.EmailAddresses) > 0 || len(csr.URIs) > 0 {
+		return sans, NewError(ErrorBadCSRType, "Only DNS names and IP addresses are allowed")
+	}
+
 	// order the DNS names and IP addresses, so that they can be compared against the canonicalized CSR
 	orderNames := make([]string, numberOfIdentifierType(DNS, o.Identifiers))
 	orderIPs := make([]net.IP, numberOfIdentifierType(IP, o.Identifiers))
@@ -279,7 +283,9 @@ func numberOfIdentifierType(typ IdentifierType, ids []Identifier) int {
 
 // canonicalize canonicalizes a CSR so that it can be compared against an Order
 // NOTE: this effectively changes the order of SANs in the CSR, which may be OK,
-// but may not be expected.
+// but may not be expected. It also adds a Subject Common Name to either the IP
+// addresses or DNS names slice, depending on whether it can be parsed as an IP
+// or not. This might result in an additional SAN in the final certificate.
 func canonicalize(csr *x509.CertificateRequest) (canonicalized *x509.CertificateRequest) {
 
 	// for clarity only; we're operating on the same object by pointer
@@ -289,16 +295,20 @@ func canonicalize(csr *x509.CertificateRequest) (canonicalized *x509.Certificate
 	// identifiers as the initial newOrder request. Identifiers of type "dns"
 	// MUST appear either in the commonName portion of the requested subject
 	// name or in an extensionRequest attribute [RFC2985] requesting a
-	// subjectAltName extension, or both.
+	// subjectAltName extension, or both. Subject Common Names that can be
-	// TODO(hs): we might want to check if the CommonName is in fact a DNS (and cannot
+	// parsed as an IP are included as an IP address for the equality check.
-	// be parsed as IP). This is related to https://github.com/smallstep/cli/pull/576
+	// If these were excluded, a certificate could contain an IP as the
-	// (ACME IP SANS)
+	// common name without having been challenged.
 	if csr.Subject.CommonName != "" {
-		// nolint:gocritic
+		if ip := net.ParseIP(csr.Subject.CommonName); ip != nil {
-		canonicalized.DNSNames = append(csr.DNSNames, csr.Subject.CommonName)
+			canonicalized.IPAddresses = append(canonicalized.IPAddresses, ip)
+		} else {
+			canonicalized.DNSNames = append(canonicalized.DNSNames, csr.Subject.CommonName)
 		}
-	canonicalized.DNSNames = uniqueSortedLowerNames(csr.DNSNames)
+	}
-	canonicalized.IPAddresses = uniqueSortedIPs(csr.IPAddresses)
+
+	canonicalized.DNSNames = uniqueSortedLowerNames(canonicalized.DNSNames)
+	canonicalized.IPAddresses = uniqueSortedIPs(canonicalized.IPAddresses)
 
 	return canonicalized
 }
@@ -340,7 +350,10 @@ func uniqueSortedIPs(ips []net.IP) (unique []net.IP) {
 	}
 	ipEntryMap := make(map[string]entry, len(ips))
 	for _, ip := range ips {
-		ipEntryMap[ip.String()] = entry{ip: ip}
+		// reparsing the IP results in the IP being represented using 16 bytes
+		// for both IPv4 as well as IPv6, even when the ips slice contains IPs that
+		// are represented by 4 bytes. This ensures a fair comparison and thus ordering.
+		ipEntryMap[ip.String()] = entry{ip: net.ParseIP(ip.String())}
 	}
 	unique = make([]net.IP, 0, len(ipEntryMap))
 	for _, entry := range ipEntryMap {

acme/order_test.go

@@ -6,10 +6,12 @@ import (
 	"crypto/x509/pkix"
 	"encoding/json"
 	"net"
+	"net/url"
 	"reflect"
 	"testing"
 	"time"
 
+	"github.com/google/go-cmp/cmp"
 	"github.com/pkg/errors"
 	"github.com/smallstep/assert"
 	"github.com/smallstep/certificates/authority"
@@ -827,69 +829,90 @@ func Test_uniqueSortedIPs(t *testing.T) {
 	tests := []struct {
 		name string
 		args args
-		wantUnique []net.IP
+		want []net.IP
 	}{
 		{
 			name: "ok/empty",
 			args: args{
 				ips: []net.IP{},
 			},
-			wantUnique: []net.IP{},
+			want: []net.IP{},
 		},
 		{
 			name: "ok/single-ipv4",
 			args: args{
 				ips: []net.IP{net.ParseIP("192.168.42.42")},
 			},
-			wantUnique: []net.IP{net.ParseIP("192.168.42.42")},
+			want: []net.IP{net.ParseIP("192.168.42.42")},
 		},
 		{
 			name: "ok/multiple-ipv4",
 			args: args{
-				ips: []net.IP{net.ParseIP("192.168.42.42"), net.ParseIP("192.168.42.10"), net.ParseIP("192.168.42.1")},
+				ips: []net.IP{net.ParseIP("192.168.42.42"), net.ParseIP("192.168.42.10"), net.ParseIP("192.168.42.1"), net.ParseIP("127.0.0.1")},
 			},
-			wantUnique: []net.IP{net.ParseIP("192.168.42.1"), net.ParseIP("192.168.42.10"), net.ParseIP("192.168.42.42")},
+			want: []net.IP{net.ParseIP("127.0.0.1"), net.ParseIP("192.168.42.1"), net.ParseIP("192.168.42.10"), net.ParseIP("192.168.42.42")},
+		}, {
+			name: "ok/multiple-ipv4-with-varying-byte-representations",
+			args: args{
+				ips: []net.IP{net.ParseIP("192.168.42.42"), net.ParseIP("192.168.42.10"), net.ParseIP("192.168.42.1"), []byte{0x7f, 0x0, 0x0, 0x1}},
+			},
+			want: []net.IP{net.ParseIP("127.0.0.1"), net.ParseIP("192.168.42.1"), net.ParseIP("192.168.42.10"), net.ParseIP("192.168.42.42")},
 		},
 		{
 			name: "ok/unique-ipv4",
 			args: args{
 				ips: []net.IP{net.ParseIP("192.168.42.42"), net.ParseIP("192.168.42.42")},
 			},
-			wantUnique: []net.IP{net.ParseIP("192.168.42.42")},
+			want: []net.IP{net.ParseIP("192.168.42.42")},
 		},
 		{
 			name: "ok/single-ipv6",
 			args: args{
 				ips: []net.IP{net.ParseIP("2001:db8::30")},
 			},
-			wantUnique: []net.IP{net.ParseIP("2001:db8::30")},
+			want: []net.IP{net.ParseIP("2001:db8::30")},
 		},
 		{
 			name: "ok/multiple-ipv6",
 			args: args{
 				ips: []net.IP{net.ParseIP("2001:db8::30"), net.ParseIP("2001:db8::20"), net.ParseIP("2001:db8::10")},
 			},
-			wantUnique: []net.IP{net.ParseIP("2001:db8::10"), net.ParseIP("2001:db8::20"), net.ParseIP("2001:db8::30")},
+			want: []net.IP{net.ParseIP("2001:db8::10"), net.ParseIP("2001:db8::20"), net.ParseIP("2001:db8::30")},
 		},
 		{
 			name: "ok/unique-ipv6",
 			args: args{
 				ips: []net.IP{net.ParseIP("2001:db8::1"), net.ParseIP("2001:db8::1")},
 			},
-			wantUnique: []net.IP{net.ParseIP("2001:db8::1")},
+			want: []net.IP{net.ParseIP("2001:db8::1")},
 		},
 		{
 			name: "ok/mixed-ipv4-and-ipv6",
 			args: args{
 				ips: []net.IP{net.ParseIP("2001:db8::1"), net.ParseIP("2001:db8::1"), net.ParseIP("192.168.42.42"), net.ParseIP("192.168.42.42")},
 			},
-			wantUnique: []net.IP{net.ParseIP("192.168.42.42"), net.ParseIP("2001:db8::1")},
+			want: []net.IP{net.ParseIP("192.168.42.42"), net.ParseIP("2001:db8::1")},
+		},
+		{
+			name: "ok/mixed-ipv4-and-ipv6-and-varying-byte-representations",
+			args: args{
+				ips: []net.IP{net.ParseIP("2001:db8::1"), net.ParseIP("2001:db8::1"), net.ParseIP("192.168.42.42"), net.ParseIP("192.168.42.42"), []byte{0x7f, 0x0, 0x0, 0x1}},
+			},
+			want: []net.IP{net.ParseIP("127.0.0.1"), net.ParseIP("192.168.42.42"), net.ParseIP("2001:db8::1")},
+		},
+		{
+			name: "ok/mixed-ipv4-and-ipv6-and-more-varying-byte-representations",
+			args: args{
+				ips: []net.IP{net.ParseIP("2001:db8::1"), net.ParseIP("2001:db8::1"), net.ParseIP("192.168.42.42"), net.ParseIP("2001:db8::2"), net.ParseIP("192.168.42.42"), []byte{0x7f, 0x0, 0x0, 0x1}, []byte{0x7f, 0x0, 0x0, 0x1}, []byte{0x7f, 0x0, 0x0, 0x2}},
+			},
+			want: []net.IP{net.ParseIP("127.0.0.1"), net.ParseIP("127.0.0.2"), net.ParseIP("192.168.42.42"), net.ParseIP("2001:db8::1"), net.ParseIP("2001:db8::2")},
 		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if gotUnique := uniqueSortedIPs(tt.args.ips); !reflect.DeepEqual(gotUnique, tt.wantUnique) {
+			got := uniqueSortedIPs(tt.args.ips)
-				t.Errorf("uniqueSortedIPs() = %v, want %v", gotUnique, tt.wantUnique)
+			if !cmp.Equal(tt.want, got) {
+				t.Errorf("uniqueSortedIPs() diff =\n%s", cmp.Diff(tt.want, got))
 			}
 		})
 	}
@@ -1124,7 +1147,7 @@ func Test_canonicalize(t *testing.T) {
 	tests := []struct {
 		name string
 		args args
-		wantCanonicalized *x509.CertificateRequest
+		want *x509.CertificateRequest
 	}{
 		{
 			name: "ok/dns",
@@ -1133,7 +1156,7 @@ func Test_canonicalize(t *testing.T) {
 					DNSNames: []string{"www.example.com", "example.com"},
 				},
 			},
-			wantCanonicalized: &x509.CertificateRequest{
+			want: &x509.CertificateRequest{
 				DNSNames:    []string{"example.com", "www.example.com"},
 				IPAddresses: []net.IP{},
 			},
@@ -1148,7 +1171,7 @@ func Test_canonicalize(t *testing.T) {
 					DNSNames: []string{"www.example.com"},
 				},
 			},
-			wantCanonicalized: &x509.CertificateRequest{
+			want: &x509.CertificateRequest{
 				Subject: pkix.Name{
 					CommonName: "example.com",
 				},
@@ -1163,7 +1186,7 @@ func Test_canonicalize(t *testing.T) {
 					IPAddresses: []net.IP{net.ParseIP("192.168.43.42"), net.ParseIP("192.168.42.42")},
 				},
 			},
-			wantCanonicalized: &x509.CertificateRequest{
+			want: &x509.CertificateRequest{
 				DNSNames:    []string{},
 				IPAddresses: []net.IP{net.ParseIP("192.168.42.42"), net.ParseIP("192.168.43.42")},
 			},
@@ -1176,7 +1199,7 @@ func Test_canonicalize(t *testing.T) {
 					IPAddresses: []net.IP{net.ParseIP("192.168.43.42"), net.ParseIP("192.168.42.42")},
 				},
 			},
-			wantCanonicalized: &x509.CertificateRequest{
+			want: &x509.CertificateRequest{
 				DNSNames:    []string{"example.com", "www.example.com"},
 				IPAddresses: []net.IP{net.ParseIP("192.168.42.42"), net.ParseIP("192.168.43.42")},
 			},
@@ -1192,7 +1215,7 @@ func Test_canonicalize(t *testing.T) {
 					IPAddresses: []net.IP{net.ParseIP("192.168.43.42"), net.ParseIP("192.168.42.42")},
 				},
 			},
-			wantCanonicalized: &x509.CertificateRequest{
+			want: &x509.CertificateRequest{
 				Subject: pkix.Name{
 					CommonName: "example.com",
 				},
@@ -1200,11 +1223,31 @@ func Test_canonicalize(t *testing.T) {
 				IPAddresses: []net.IP{net.ParseIP("192.168.42.42"), net.ParseIP("192.168.43.42")},
 			},
 		},
+		{
+			name: "ok/ip-common-name",
+			args: args{
+				csr: &x509.CertificateRequest{
+					Subject: pkix.Name{
+						CommonName: "127.0.0.1",
+					},
+					DNSNames:    []string{"example.com"},
+					IPAddresses: []net.IP{net.ParseIP("192.168.43.42"), net.ParseIP("192.168.42.42")},
+				},
+			},
+			want: &x509.CertificateRequest{
+				Subject: pkix.Name{
+					CommonName: "127.0.0.1",
+				},
+				DNSNames:    []string{"example.com"},
+				IPAddresses: []net.IP{net.ParseIP("127.0.0.1"), net.ParseIP("192.168.42.42"), net.ParseIP("192.168.43.42")},
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if gotCanonicalized := canonicalize(tt.args.csr); !reflect.DeepEqual(gotCanonicalized, tt.wantCanonicalized) {
+			got := canonicalize(tt.args.csr)
-				t.Errorf("canonicalize() = %v, want %v", gotCanonicalized, tt.wantCanonicalized)
+			if !cmp.Equal(tt.want, got) {
+				t.Errorf("canonicalize() diff =\n%s", cmp.Diff(tt.want, got))
 			}
 		})
 	}
@@ -1238,6 +1281,39 @@ func TestOrder_sans(t *testing.T) {
 			},
 			err: nil,
 		},
+		{
+			name: "fail/invalid-alternative-name-email",
+			fields: fields{
+				Identifiers: []Identifier{},
+			},
+			csr: &x509.CertificateRequest{
+				Subject: pkix.Name{
+					CommonName: "foo.internal",
+				},
+				EmailAddresses: []string{"test@example.com"},
+			},
+			want: []x509util.SubjectAlternativeName{},
+			err:  NewError(ErrorBadCSRType, "Only DNS names and IP addresses are allowed"),
+		},
+		{
+			name: "fail/invalid-alternative-name-uri",
+			fields: fields{
+				Identifiers: []Identifier{},
+			},
+			csr: &x509.CertificateRequest{
+				Subject: pkix.Name{
+					CommonName: "foo.internal",
+				},
+				URIs: []*url.URL{
+					{
+						Scheme: "https://",
+						Host:   "smallstep.com",
+					},
+				},
+			},
+			want: []x509util.SubjectAlternativeName{},
+			err:  NewError(ErrorBadCSRType, "Only DNS names and IP addresses are allowed"),
+		},
 		{
 			name: "fail/error-names-length-mismatch",
 			fields: fields{

ca/bootstrap.go

@@ -2,12 +2,14 @@ package ca
 
 import (
 	"context"
+	"crypto"
 	"crypto/tls"
 	"net"
 	"net/http"
 	"strings"
 
 	"github.com/pkg/errors"
+	"github.com/smallstep/certificates/api"
 	"go.step.sm/crypto/jose"
 )
 
@@ -58,25 +60,21 @@ func Bootstrap(token string) (*Client, error) {
 //   }
 //   resp, err := client.Get("https://internal.smallstep.com")
 func BootstrapClient(ctx context.Context, token string, options ...TLSOption) (*http.Client, error) {
-	client, err := Bootstrap(token)
+	b, err := createBootstrap(token)
 	if err != nil {
 		return nil, err
 	}
 
-	req, pk, err := CreateSignRequest(token)
+	// Make sure the tlsConfig has all supported roots on RootCAs.
-	if err != nil {
+	//
-		return nil, err
+	// The roots request is only supported if identity certificates are not
-	}
+	// required. In all cases the current root is also added after applying all
-
+	// options too.
-	sign, err := client.Sign(req)
+	if !b.RequireClientAuth {
-	if err != nil {
-		return nil, err
-	}
-
-	// Make sure the tlsConfig have all supported roots on RootCAs
 		options = append(options, AddRootsToRootCAs())
+	}
 
-	transport, err := client.Transport(ctx, sign, pk, options...)
+	transport, err := b.Client.Transport(ctx, b.SignResponse, b.PrivateKey, options...)
 	if err != nil {
 		return nil, err
 	}
@@ -120,25 +118,21 @@ func BootstrapServer(ctx context.Context, token string, base *http.Server, optio
 		return nil, errors.New("server TLSConfig is already set")
 	}
 
-	client, err := Bootstrap(token)
+	b, err := createBootstrap(token)
 	if err != nil {
 		return nil, err
 	}
 
-	req, pk, err := CreateSignRequest(token)
+	// Make sure the tlsConfig has all supported roots on RootCAs.
-	if err != nil {
+	//
-		return nil, err
+	// The roots request is only supported if identity certificates are not
-	}
+	// required. In all cases the current root is also added after applying all
-
+	// options too.
-	sign, err := client.Sign(req)
+	if !b.RequireClientAuth {
-	if err != nil {
-		return nil, err
-	}
-
-	// Make sure the tlsConfig have all supported roots on ClientCAs and RootCAs
 		options = append(options, AddRootsToCAs())
+	}
 
-	tlsConfig, err := client.GetServerTLSConfig(ctx, sign, pk, options...)
+	tlsConfig, err := b.Client.GetServerTLSConfig(ctx, b.SignResponse, b.PrivateKey, options...)
 	if err != nil {
 		return nil, err
 	}
@@ -172,11 +166,46 @@ func BootstrapServer(ctx context.Context, token string, base *http.Server, optio
 //   ... // register services
 //   srv.Serve(lis)
 func BootstrapListener(ctx context.Context, token string, inner net.Listener, options ...TLSOption) (net.Listener, error) {
+	b, err := createBootstrap(token)
+	if err != nil {
+		return nil, err
+	}
+
+	// Make sure the tlsConfig has all supported roots on RootCAs.
+	//
+	// The roots request is only supported if identity certificates are not
+	// required. In all cases the current root is also added after applying all
+	// options too.
+	if !b.RequireClientAuth {
+		options = append(options, AddRootsToCAs())
+	}
+
+	tlsConfig, err := b.Client.GetServerTLSConfig(ctx, b.SignResponse, b.PrivateKey, options...)
+	if err != nil {
+		return nil, err
+	}
+
+	return tls.NewListener(inner, tlsConfig), nil
+}
+
+type bootstrap struct {
+	Client            *Client
+	RequireClientAuth bool
+	SignResponse      *api.SignResponse
+	PrivateKey        crypto.PrivateKey
+}
+
+func createBootstrap(token string) (*bootstrap, error) {
 	client, err := Bootstrap(token)
 	if err != nil {
 		return nil, err
 	}
 
+	version, err := client.Version()
+	if err != nil {
+		return nil, err
+	}
+
 	req, pk, err := CreateSignRequest(token)
 	if err != nil {
 		return nil, err
@@ -187,13 +216,10 @@ func BootstrapListener(ctx context.Context, token string, inner net.Listener, op
 		return nil, err
 	}
 
-	// Make sure the tlsConfig have all supported roots on ClientCAs and RootCAs
+	return &bootstrap{
-	options = append(options, AddRootsToCAs())
+		Client:            client,
-
+		RequireClientAuth: version.RequireClientAuthentication,
-	tlsConfig, err := client.GetServerTLSConfig(ctx, sign, pk, options...)
+		SignResponse:      sign,
-	if err != nil {
+		PrivateKey:        pk,
-		return nil, err
+	}, nil
-	}
-
-	return tls.NewListener(inner, tlsConfig), nil
 }

ca/bootstrap_test.go

@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"reflect"
+	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -15,6 +16,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/smallstep/certificates/api"
 	"github.com/smallstep/certificates/authority"
+	"github.com/smallstep/certificates/errs"
 	"go.step.sm/crypto/jose"
 	"go.step.sm/crypto/randutil"
 )
@@ -74,6 +76,30 @@ func startCAServer(configFile string) (*CA, string, error) {
 	return ca, caURL, nil
 }
 
+func mTLSMiddleware(next http.Handler, nonAuthenticatedPaths ...string) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/version" {
+			api.JSON(w, api.VersionResponse{
+				Version:                     "test",
+				RequireClientAuthentication: true,
+			})
+			return
+		}
+
+		for _, s := range nonAuthenticatedPaths {
+			if strings.HasPrefix(r.URL.Path, s) || strings.HasPrefix(r.URL.Path, "/1.0"+s) {
+				next.ServeHTTP(w, r)
+			}
+		}
+		isMTLS := r.TLS != nil && len(r.TLS.PeerCertificates) > 0
+		if !isMTLS {
+			api.WriteError(w, errs.Unauthorized("missing peer certificate"))
+		} else {
+			next.ServeHTTP(w, r)
+		}
+	})
+}
+
 func generateBootstrapToken(ca, subject, sha string) string {
 	now := time.Now()
 	jwk, err := jose.ReadKey("testdata/secrets/ott_mariano_priv.jwk", jose.WithPassword([]byte("password")))
@@ -171,6 +197,15 @@ func TestBootstrapServerWithoutMTLS(t *testing.T) {
 	token := func() string {
 		return generateBootstrapToken(srv.URL, "subject", "ef742f95dc0d8aa82d3cca4017af6dac3fce84290344159891952d18c53eefe7")
 	}
+
+	mtlsServer := startCABootstrapServer()
+	next := mtlsServer.Config.Handler
+	mtlsServer.Config.Handler = mTLSMiddleware(next, "/root/", "/sign")
+	defer mtlsServer.Close()
+	mtlsToken := func() string {
+		return generateBootstrapToken(mtlsServer.URL, "subject", "ef742f95dc0d8aa82d3cca4017af6dac3fce84290344159891952d18c53eefe7")
+	}
+
 	type args struct {
 		ctx   context.Context
 		token string
@@ -182,6 +217,7 @@ func TestBootstrapServerWithoutMTLS(t *testing.T) {
 		wantErr bool
 	}{
 		{"ok", args{context.Background(), token(), &http.Server{}}, false},
+		{"ok mtls", args{context.Background(), mtlsToken(), &http.Server{}}, false},
 		{"fail", args{context.Background(), "bad-token", &http.Server{}}, true},
 		{"fail with TLSConfig", args{context.Background(), token(), &http.Server{TLSConfig: &tls.Config{}}}, true},
 	}
@@ -217,6 +253,15 @@ func TestBootstrapServerWithMTLS(t *testing.T) {
 	token := func() string {
 		return generateBootstrapToken(srv.URL, "subject", "ef742f95dc0d8aa82d3cca4017af6dac3fce84290344159891952d18c53eefe7")
 	}
+
+	mtlsServer := startCABootstrapServer()
+	next := mtlsServer.Config.Handler
+	mtlsServer.Config.Handler = mTLSMiddleware(next, "/root/", "/sign")
+	defer mtlsServer.Close()
+	mtlsToken := func() string {
+		return generateBootstrapToken(mtlsServer.URL, "subject", "ef742f95dc0d8aa82d3cca4017af6dac3fce84290344159891952d18c53eefe7")
+	}
+
 	type args struct {
 		ctx   context.Context
 		token string
@@ -228,6 +273,7 @@ func TestBootstrapServerWithMTLS(t *testing.T) {
 		wantErr bool
 	}{
 		{"ok", args{context.Background(), token(), &http.Server{}}, false},
+		{"ok mtls", args{context.Background(), mtlsToken(), &http.Server{}}, false},
 		{"fail", args{context.Background(), "bad-token", &http.Server{}}, true},
 		{"fail with TLSConfig", args{context.Background(), token(), &http.Server{TLSConfig: &tls.Config{}}}, true},
 	}
@@ -263,6 +309,15 @@ func TestBootstrapClient(t *testing.T) {
 	token := func() string {
 		return generateBootstrapToken(srv.URL, "subject", "ef742f95dc0d8aa82d3cca4017af6dac3fce84290344159891952d18c53eefe7")
 	}
+
+	mtlsServer := startCABootstrapServer()
+	next := mtlsServer.Config.Handler
+	mtlsServer.Config.Handler = mTLSMiddleware(next, "/root/", "/sign")
+	defer mtlsServer.Close()
+	mtlsToken := func() string {
+		return generateBootstrapToken(mtlsServer.URL, "subject", "ef742f95dc0d8aa82d3cca4017af6dac3fce84290344159891952d18c53eefe7")
+	}
+
 	type args struct {
 		ctx   context.Context
 		token string
@@ -273,6 +328,7 @@ func TestBootstrapClient(t *testing.T) {
 		wantErr bool
 	}{
 		{"ok", args{context.Background(), token()}, false},
+		{"ok mtls", args{context.Background(), mtlsToken()}, false},
 		{"fail", args{context.Background(), "bad-token"}, true},
 	}
 	for _, tt := range tests {
@@ -541,6 +597,15 @@ func TestBootstrapListener(t *testing.T) {
 	token := func() string {
 		return generateBootstrapToken(srv.URL, "127.0.0.1", "ef742f95dc0d8aa82d3cca4017af6dac3fce84290344159891952d18c53eefe7")
 	}
+
+	mtlsServer := startCABootstrapServer()
+	next := mtlsServer.Config.Handler
+	mtlsServer.Config.Handler = mTLSMiddleware(next, "/root/", "/sign")
+	defer mtlsServer.Close()
+	mtlsToken := func() string {
+		return generateBootstrapToken(mtlsServer.URL, "127.0.0.1", "ef742f95dc0d8aa82d3cca4017af6dac3fce84290344159891952d18c53eefe7")
+	}
+
 	type args struct {
 		token string
 	}
@@ -550,6 +615,7 @@ func TestBootstrapListener(t *testing.T) {
 		wantErr bool
 	}{
 		{"ok", args{token()}, false},
+		{"ok mtls", args{mtlsToken()}, false},
 		{"fail", args{"bad-token"}, true},
 	}
 	for _, tt := range tests {

ca/tls_options.go

@@ -115,6 +115,7 @@ func AddRootCA(cert *x509.Certificate) TLSOption {
 		if ctx.Config.RootCAs == nil {
 			ctx.Config.RootCAs = x509.NewCertPool()
 		}
+		ctx.hasRootCA = true
 		ctx.Config.RootCAs.AddCert(cert)
 		ctx.mutableConfig.AddImmutableRootCACert(cert)
 		return nil
@@ -129,6 +130,7 @@ func AddClientCA(cert *x509.Certificate) TLSOption {
 		if ctx.Config.ClientCAs == nil {
 			ctx.Config.ClientCAs = x509.NewCertPool()
 		}
+		ctx.hasClientCA = true
 		ctx.Config.ClientCAs.AddCert(cert)
 		ctx.mutableConfig.AddImmutableClientCACert(cert)
 		return nil

kms/pkcs11/pkcs11.go

@@ -7,6 +7,7 @@ import (
 	"context"
 	"crypto"
 	"crypto/elliptic"
+	"crypto/rsa"
 	"crypto/x509"
 	"encoding/hex"
 	"fmt"
@@ -142,8 +143,7 @@ func (k *PKCS11) CreateKey(req *apiv1.CreateKeyRequest) (*apiv1.CreateKeyRespons
 	}, nil
 }
 
-// CreateSigner creates a signer using the key present in the PKCS#11 MODULE signature
+// CreateSigner creates a signer using a key present in the PKCS#11 module.
-// slot.
 func (k *PKCS11) CreateSigner(req *apiv1.CreateSignerRequest) (crypto.Signer, error) {
 	if req.SigningKey == "" {
 		return nil, errors.New("createSignerRequest 'signingKey' cannot be empty")
@@ -157,6 +157,27 @@ func (k *PKCS11) CreateSigner(req *apiv1.CreateSignerRequest) (crypto.Signer, er
 	return signer, nil
 }
 
+// CreateDecrypter creates a decrypter using a key present in the PKCS#11
+// module.
+func (k *PKCS11) CreateDecrypter(req *apiv1.CreateDecrypterRequest) (crypto.Decrypter, error) {
+	if req.DecryptionKey == "" {
+		return nil, errors.New("createDecrypterRequest 'decryptionKey' cannot be empty")
+	}
+
+	signer, err := findSigner(k.p11, req.DecryptionKey)
+	if err != nil {
+		return nil, errors.Wrap(err, "createDecrypterRequest failed")
+	}
+
+	// Only RSA keys will implement the Decrypter interface.
+	if _, ok := signer.Public().(*rsa.PublicKey); ok {
+		if dec, ok := signer.(crypto.Decrypter); ok {
+			return dec, nil
+		}
+	}
+	return nil, errors.New("createDecrypterRequest failed: signer does not implement crypto.Decrypter")
+}
+
 // LoadCertificate implements kms.CertificateManager and loads a certificate
 // from the YubiKey.
 func (k *PKCS11) LoadCertificate(req *apiv1.LoadCertificateRequest) (*x509.Certificate, error) {

kms/pkcs11/pkcs11_test.go

@@ -4,6 +4,7 @@
 package pkcs11
 
 import (
+	"bytes"
 	"context"
 	"crypto"
 	"crypto/ecdsa"
@@ -491,6 +492,86 @@ func TestPKCS11_CreateSigner(t *testing.T) {
 	}
 }
 
+func TestPKCS11_CreateDecrypter(t *testing.T) {
+	k := setupPKCS11(t)
+	data := []byte("buggy-coheir-RUBRIC-rabbet-liberal-eaglet-khartoum-stagger")
+
+	type args struct {
+		req *apiv1.CreateDecrypterRequest
+	}
+	tests := []struct {
+		name    string
+		args    args
+		wantErr bool
+	}{
+		{"RSA", args{&apiv1.CreateDecrypterRequest{
+			DecryptionKey: "pkcs11:id=7371;object=rsa-key",
+		}}, false},
+		{"RSA PSS", args{&apiv1.CreateDecrypterRequest{
+			DecryptionKey: "pkcs11:id=7372;object=rsa-pss-key",
+		}}, false},
+		{"ECDSA P256", args{&apiv1.CreateDecrypterRequest{
+			DecryptionKey: "pkcs11:id=7373;object=ecdsa-p256-key",
+		}}, true},
+		{"ECDSA P384", args{&apiv1.CreateDecrypterRequest{
+			DecryptionKey: "pkcs11:id=7374;object=ecdsa-p384-key",
+		}}, true},
+		{"ECDSA P521", args{&apiv1.CreateDecrypterRequest{
+			DecryptionKey: "pkcs11:id=7375;object=ecdsa-p521-key",
+		}}, true},
+		{"fail DecryptionKey", args{&apiv1.CreateDecrypterRequest{
+			DecryptionKey: "",
+		}}, true},
+		{"fail uri", args{&apiv1.CreateDecrypterRequest{
+			DecryptionKey: "https:id=7375;object=ecdsa-p521-key",
+		}}, true},
+		{"fail FindKeyPair", args{&apiv1.CreateDecrypterRequest{
+			DecryptionKey: "pkcs11:foo=bar",
+		}}, true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := k.CreateDecrypter(tt.args.req)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("PKCS11.CreateDecrypter() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+
+			if got != nil {
+				pub := got.Public().(*rsa.PublicKey)
+				// PKCS#1 v1.5
+				enc, err := rsa.EncryptPKCS1v15(rand.Reader, pub, data)
+				if err != nil {
+					t.Errorf("rsa.EncryptPKCS1v15() error = %v", err)
+					return
+				}
+				dec, err := got.Decrypt(rand.Reader, enc, nil)
+				if err != nil {
+					t.Errorf("PKCS1v15.Decrypt() error = %v", err)
+				} else if !bytes.Equal(dec, data) {
+					t.Errorf("PKCS1v15.Decrypt() failed got = %s, want = %s", dec, data)
+				}
+
+				// RSA-OAEP
+				enc, err = rsa.EncryptOAEP(crypto.SHA256.New(), rand.Reader, pub, data, []byte("label"))
+				if err != nil {
+					t.Errorf("rsa.EncryptOAEP() error = %v", err)
+					return
+				}
+				dec, err = got.Decrypt(rand.Reader, enc, &rsa.OAEPOptions{
+					Hash:  crypto.SHA256,
+					Label: []byte("label"),
+				})
+				if err != nil {
+					t.Errorf("RSA-OAEP.Decrypt() error = %v", err)
+				} else if !bytes.Equal(dec, data) {
+					t.Errorf("RSA-OAEP.Decrypt() RSA-OAEP failed got = %s, want = %s", dec, data)
+				}
+			}
+		})
+	}
+}
+
 func TestPKCS11_LoadCertificate(t *testing.T) {
 	k := setupPKCS11(t)