Initial QSfera import

Server/vendor/github.com/lestrrat-go/jwx/v3/jwe/headers.go

@@ -0,0 +1,95 @@
+package jwe
+
+import (
+	"fmt"
+
+	"github.com/lestrrat-go/jwx/v3/internal/base64"
+	"github.com/lestrrat-go/jwx/v3/internal/json"
+)
+
+type isZeroer interface {
+	isZero() bool
+}
+
+func (h *stdHeaders) isZero() bool {
+	return h.agreementPartyUInfo == nil &&
+		h.agreementPartyVInfo == nil &&
+		h.algorithm == nil &&
+		h.compression == nil &&
+		h.contentEncryption == nil &&
+		h.contentType == nil &&
+		h.critical == nil &&
+		h.ephemeralPublicKey == nil &&
+		h.jwk == nil &&
+		h.jwkSetURL == nil &&
+		h.keyID == nil &&
+		h.typ == nil &&
+		h.x509CertChain == nil &&
+		h.x509CertThumbprint == nil &&
+		h.x509CertThumbprintS256 == nil &&
+		h.x509URL == nil &&
+		len(h.privateParams) == 0
+}
+
+func (h *stdHeaders) Clone() (Headers, error) {
+	dst := NewHeaders()
+	if err := h.Copy(dst); err != nil {
+		return nil, fmt.Errorf(`failed to copy header contents to new object: %w`, err)
+	}
+	return dst, nil
+}
+
+func (h *stdHeaders) Copy(dst Headers) error {
+	for _, key := range h.Keys() {
+		var v any
+		if err := h.Get(key, &v); err != nil {
+			return fmt.Errorf(`jwe.Headers: Copy: failed to get header %q: %w`, key, err)
+		}
+
+		if err := dst.Set(key, v); err != nil {
+			return fmt.Errorf(`jwe.Headers: Copy: failed to set header %q: %w`, key, err)
+		}
+	}
+	return nil
+}
+
+func (h *stdHeaders) Merge(h2 Headers) (Headers, error) {
+	h3 := NewHeaders()
+
+	if h != nil {
+		if err := h.Copy(h3); err != nil {
+			return nil, fmt.Errorf(`failed to copy headers from receiver: %w`, err)
+		}
+	}
+
+	if h2 != nil {
+		if err := h2.Copy(h3); err != nil {
+			return nil, fmt.Errorf(`failed to copy headers from argument: %w`, err)
+		}
+	}
+
+	return h3, nil
+}
+
+func (h *stdHeaders) Encode() ([]byte, error) {
+	buf, err := json.Marshal(h)
+	if err != nil {
+		return nil, fmt.Errorf(`failed to marshal headers to JSON prior to encoding: %w`, err)
+	}
+
+	return base64.Encode(buf), nil
+}
+
+func (h *stdHeaders) Decode(buf []byte) error {
+	// base64 json string -> json object representation of header
+	decoded, err := base64.Decode(buf)
+	if err != nil {
+		return fmt.Errorf(`failed to unmarshal base64 encoded buffer: %w`, err)
+	}
+
+	if err := json.Unmarshal(decoded, h); err != nil {
+		return fmt.Errorf(`failed to unmarshal buffer: %w`, err)
+	}
+
+	return nil
+}