Use base64 encoded signing key format

acme/api/order_test.go

@@ -885,6 +885,10 @@ func TestHandler_NewOrder(t *testing.T) {
 	u := fmt.Sprintf("%s/acme/%s/order/ordID",
 		baseURL.String(), escProvName)
 
+	fakeWireSigningKey := `-----BEGIN PUBLIC KEY-----
+MCowBQYDK2VwAyEA5c+4NKZSNQcR1T8qN6SjwgdPZQ0Ge12Ylx/YeGAJ35k=
+-----END PUBLIC KEY-----`
+
 	type test struct {
 		ca         acme.CertificateAuthority
 		db         acme.DB
@@ -1737,7 +1741,9 @@ func TestHandler_NewOrder(t *testing.T) {
 							Now:                        time.Now,
 						},
 					},
-					DPOP: &wire.DPOPOptions{},
+					DPOP: &wire.DPOPOptions{
+						SigningKey: []byte(fakeWireSigningKey),
+					},
 				},
 			})
 			acc := &acme.Account{ID: "accID"}

acme/api/wire_integration_test.go

@@ -51,6 +51,9 @@ func newWireProvisionerWithOptions(t *testing.T, options *provisioner.Options) *
 }
 
 func TestWireIntegration(t *testing.T) {
+	fakeKey := `-----BEGIN PUBLIC KEY-----
+MCowBQYDK2VwAyEA5c+4NKZSNQcR1T8qN6SjwgdPZQ0Ge12Ylx/YeGAJ35k=
+-----END PUBLIC KEY-----`
 	prov := newWireProvisionerWithOptions(t, &provisioner.Options{
 		Wire: &wire.Options{
 			OIDC: &wire.OIDCOptions{
@@ -72,7 +75,9 @@ func TestWireIntegration(t *testing.T) {
 					Now:                        time.Now,
 				},
 			},
-			DPOP: &wire.DPOPOptions{},
+			DPOP: &wire.DPOPOptions{
+				SigningKey: []byte(fakeKey),
+			},
 		},
 	})
 

acme/challenge.go

@@ -490,10 +490,9 @@ func wireDPOP01Validate(ctx context.Context, ch *Challenge, db DB, jwk *jose.JSO
 		return WrapErrorISE(err, "invalid Go template registered for 'target'")
 	}
 
-	key := dpopOptions.GetSigningKey()
 	params := verifyParams{
 		token:     dpopPayload.AccessToken,
-		key:       key,
+		key:       dpopOptions.GetSigningKey(),
 		kid:       kid,
 		issuer:    issuer,
 		wireID:    wireID,
@@ -548,7 +547,7 @@ type wireDpopToken map[string]any
 
 type verifyParams struct {
 	token     string
-	key       string
+	key       crypto.PublicKey
 	issuer    string
 	kid       string
 	wireID    wire.ID
@@ -557,23 +556,13 @@ type verifyParams struct {
 }
 
 func parseAndVerifyWireAccessToken(v verifyParams) (*wireAccessToken, *wireDpopToken, error) {
-	k, err := pemutil.Parse([]byte(v.key)) // TODO(hs): move this to earlier in the configuration process? Do it once?
-	if err != nil {
-		return nil, nil, fmt.Errorf("failed parsing public key: %w", err)
-	}
-
-	pk, ok := k.(ed25519.PublicKey) // TODO(hs): allow more key types
-	if !ok {
-		return nil, nil, fmt.Errorf("unexpected type: %T", k)
-	}
-
 	jwt, err := jose.ParseSigned(v.token)
 	if err != nil {
 		return nil, nil, fmt.Errorf("failed parsing token: %w", err)
 	}
 
 	var accessToken wireAccessToken
-	if err = jwt.Claims(pk, &accessToken); err != nil {
+	if err = jwt.Claims(v.key, &accessToken); err != nil {
 		return nil, nil, fmt.Errorf("failed getting token claims: %w", err)
 	}
 

acme/challenge_test.go

@@ -34,6 +34,7 @@ import (
 	"go.step.sm/crypto/jose"
 	"go.step.sm/crypto/keyutil"
 	"go.step.sm/crypto/minica"
+	"go.step.sm/crypto/pemutil"
 	"go.step.sm/crypto/x509util"
 
 	"github.com/smallstep/certificates/acme/wire"
@@ -4305,10 +4306,11 @@ func createSubjectAltNameExtension(dnsNames, emailAddresses x509util.MultiString
 }
 
 func Test_parseAndVerifyWireAccessToken(t *testing.T) {
-	key := `
------BEGIN PUBLIC KEY-----
+	key := `-----BEGIN PUBLIC KEY-----
 MCowBQYDK2VwAyEA5c+4NKZSNQcR1T8qN6SjwgdPZQ0Ge12Ylx/YeGAJ35k=
------END PUBLIC KEY-----` // TODO(hs): different format?
+-----END PUBLIC KEY-----`
+	publicKey, err := pemutil.Parse([]byte(key))
+	require.NoError(t, err)
 	issuer := "https://wire.example.com/clients/314845990100130665/access-token"
 	kid := "QAv6C9q47Cyfd1u9z6uX3V_o-t11S8p81wLH-oTRlh0"
 	wireID := wire.ID{
@@ -4327,7 +4329,7 @@ MCowBQYDK2VwAyEA5c+4NKZSNQcR1T8qN6SjwgdPZQ0Ge12Ylx/YeGAJ35k=
 
 	at, dpop, err := parseAndVerifyWireAccessToken(verifyParams{
 		token:     token,
-		key:       key,
+		key:       publicKey,
 		kid:       kid,
 		issuer:    issuer,
 		wireID:    wireID,

authority/provisioner/wire/dpop_options.go

@@ -2,23 +2,31 @@ package wire
 
 import (
 	"bytes"
+	"crypto"
 	"errors"
 	"fmt"
 	"text/template"
+
+	"go.step.sm/crypto/pemutil"
 )
 
 type DPOPOptions struct {
 	// Public part of the  signing key for DPoP access token
-	SigningKey string `json:"key"`
+	SigningKey []byte `json:"key"`
 	// URI template acme client must call to fetch the DPoP challenge proof (an access token from wire-server)
 	Target string `json:"target"`
 }
 
-func (o *DPOPOptions) GetSigningKey() string {
+func (o *DPOPOptions) GetSigningKey() crypto.PublicKey {
 	if o == nil {
-		return ""
+		return nil
 	}
-	return o.SigningKey
+	k, err := pemutil.Parse(o.SigningKey) // TODO(hs): do this once?
+	if err != nil {
+		return nil
+	}
+
+	return k
 }
 
 func (o *DPOPOptions) GetTarget() string {
@@ -44,6 +52,9 @@ func (o *DPOPOptions) EvaluateTarget(deviceID string) (string, error) {
 }
 
 func (o *DPOPOptions) validate() error {
+	if _, err := pemutil.Parse(o.SigningKey); err != nil {
+		return fmt.Errorf("failed parsing key: %w", err)
+	}
 	if _, err := template.New("DeviceID").Parse(o.GetTarget()); err != nil {
 		return fmt.Errorf("failed parsing template: %w", err)
 	}

authority/provisioner/wire/wire_options_test.go

@@ -8,6 +8,10 @@ import (
 )
 
 func TestOptions_Validate(t *testing.T) {
+	key := []byte(`-----BEGIN PUBLIC KEY-----
+MCowBQYDK2VwAyEA5c+4NKZSNQcR1T8qN6SjwgdPZQ0Ge12Ylx/YeGAJ35k=
+-----END PUBLIC KEY-----`)
+
 	type fields struct {
 		OIDC *OIDCOptions
 		DPOP *DPOPOptions
@@ -26,7 +30,9 @@ func TestOptions_Validate(t *testing.T) {
 					},
 					Config: &Config{},
 				},
-				DPOP: &DPOPOptions{},
+				DPOP: &DPOPOptions{
+					SigningKey: key,
+				},
 			},
 			expectedErr: nil,
 		},
@@ -90,6 +96,22 @@ func TestOptions_Validate(t *testing.T) {
 			},
 			expectedErr: errors.New("no DPoP options available"),
 		},
+		{
+			name: "fail/invalid-key",
+			fields: fields{
+				OIDC: &OIDCOptions{
+					Provider: &Provider{
+						IssuerURL: "https://example.com",
+					},
+					Config: &Config{},
+				},
+				DPOP: &DPOPOptions{
+					SigningKey: []byte{0x00},
+					Target:     "",
+				},
+			},
+			expectedErr: errors.New(`failed validating DPoP options: failed parsing key: error decoding PEM: not a valid PEM encoded block`),
+		},
 		{
 			name: "fail/target-template",
 			fields: fields{
@@ -100,7 +122,8 @@ func TestOptions_Validate(t *testing.T) {
 					Config: &Config{},
 				},
 				DPOP: &DPOPOptions{
-					Target: "{{}",
+					SigningKey: key,
+					Target:     "{{}",
 				},
 			},
 			expectedErr: errors.New(`failed validating DPoP options: failed parsing template: template: DeviceID:1: unexpected "}" in command`),