Migrate to go-acme/lego.

vendor/github.com/go-acme/lego/acme/api/internal/secure/jws.go

@@ -0,0 +1,134 @@
+package secure
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rsa"
+	"encoding/base64"
+	"errors"
+	"fmt"
+
+	"github.com/go-acme/lego/acme/api/internal/nonces"
+	jose "gopkg.in/square/go-jose.v2"
+)
+
+// JWS Represents a JWS.
+type JWS struct {
+	privKey crypto.PrivateKey
+	kid     string // Key identifier
+	nonces  *nonces.Manager
+}
+
+// NewJWS Create a new JWS.
+func NewJWS(privateKey crypto.PrivateKey, kid string, nonceManager *nonces.Manager) *JWS {
+	return &JWS{
+		privKey: privateKey,
+		nonces:  nonceManager,
+		kid:     kid,
+	}
+}
+
+// SetKid Sets a key identifier.
+func (j *JWS) SetKid(kid string) {
+	j.kid = kid
+}
+
+// SignContent Signs a content with the JWS.
+func (j *JWS) SignContent(url string, content []byte) (*jose.JSONWebSignature, error) {
+	var alg jose.SignatureAlgorithm
+	switch k := j.privKey.(type) {
+	case *rsa.PrivateKey:
+		alg = jose.RS256
+	case *ecdsa.PrivateKey:
+		if k.Curve == elliptic.P256() {
+			alg = jose.ES256
+		} else if k.Curve == elliptic.P384() {
+			alg = jose.ES384
+		}
+	}
+
+	signKey := jose.SigningKey{
+		Algorithm: alg,
+		Key:       jose.JSONWebKey{Key: j.privKey, KeyID: j.kid},
+	}
+
+	options := jose.SignerOptions{
+		NonceSource: j.nonces,
+		ExtraHeaders: map[jose.HeaderKey]interface{}{
+			"url": url,
+		},
+	}
+
+	if j.kid == "" {
+		options.EmbedJWK = true
+	}
+
+	signer, err := jose.NewSigner(signKey, &options)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create jose signer -> %v", err)
+	}
+
+	signed, err := signer.Sign(content)
+	if err != nil {
+		return nil, fmt.Errorf("failed to sign content -> %v", err)
+	}
+	return signed, nil
+}
+
+// SignEABContent Signs an external account binding content with the JWS.
+func (j *JWS) SignEABContent(url, kid string, hmac []byte) (*jose.JSONWebSignature, error) {
+	jwk := jose.JSONWebKey{Key: j.privKey}
+	jwkJSON, err := jwk.Public().MarshalJSON()
+	if err != nil {
+		return nil, fmt.Errorf("acme: error encoding eab jwk key: %v", err)
+	}
+
+	signer, err := jose.NewSigner(
+		jose.SigningKey{Algorithm: jose.HS256, Key: hmac},
+		&jose.SignerOptions{
+			EmbedJWK: false,
+			ExtraHeaders: map[jose.HeaderKey]interface{}{
+				"kid": kid,
+				"url": url,
+			},
+		},
+	)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create External Account Binding jose signer -> %v", err)
+	}
+
+	signed, err := signer.Sign(jwkJSON)
+	if err != nil {
+		return nil, fmt.Errorf("failed to External Account Binding sign content -> %v", err)
+	}
+
+	return signed, nil
+}
+
+// GetKeyAuthorization Gets the key authorization for a token.
+func (j *JWS) GetKeyAuthorization(token string) (string, error) {
+	var publicKey crypto.PublicKey
+	switch k := j.privKey.(type) {
+	case *ecdsa.PrivateKey:
+		publicKey = k.Public()
+	case *rsa.PrivateKey:
+		publicKey = k.Public()
+	}
+
+	// Generate the Key Authorization for the challenge
+	jwk := &jose.JSONWebKey{Key: publicKey}
+	if jwk == nil {
+		return "", errors.New("could not generate JWK from key")
+	}
+
+	thumbBytes, err := jwk.Thumbprint(crypto.SHA256)
+	if err != nil {
+		return "", err
+	}
+
+	// unpad the base64URL
+	keyThumb := base64.RawURLEncoding.EncodeToString(thumbBytes)
+
+	return token + "." + keyThumb, nil
+}