callbacks service draft

api/edge/callbacks/internal/signing/module.go

@@ -0,0 +1,36 @@
+package signing
+
+import (
+	"context"
+	"time"
+
+	"github.com/tech/sendico/edge/callbacks/internal/secrets"
+	"github.com/tech/sendico/pkg/mlogger"
+)
+
+const (
+	ModeNone       = "none"
+	ModeHMACSHA256 = "hmac_sha256"
+)
+
+// SignedPayload is what gets sent over HTTP.
+type SignedPayload struct {
+	Body    []byte
+	Headers map[string]string
+}
+
+// Signer signs callback payloads.
+type Signer interface {
+	Sign(ctx context.Context, mode, secretRef string, payload []byte, now time.Time) (*SignedPayload, error)
+}
+
+// Dependencies configures signer service.
+type Dependencies struct {
+	Logger   mlogger.Logger
+	Provider secrets.Provider
+}
+
+// New creates signer service.
+func New(deps Dependencies) (Signer, error) {
+	return newService(deps)
+}