Add Metadata Decryption

api/metadata.go

@@ -0,0 +1,41 @@
+package api
+
+import (
+	"fmt"
+
+	"github.com/ProtonMail/gopenpgp/v3/crypto"
+)
+
+// ResourceMetadataTypePasswordAndDescription
+type ResourceMetadataTypePasswordAndDescription struct {
+	ObjectType     string   `json:"object_type"`
+	ResourceTypeID string   `json:"resource_type_id,omitempty"`
+	Name           string   `json:"name,omitempty"`
+	Username       string   `json:"username,omitempty"`
+	URIs           []string `json:"uris,omitempty"`
+	Description    string   `json:"description,omitempty"`
+}
+
+func (c *Client) DecryptMetadata(metadataKey *crypto.Key, armoredCiphertext string) (string, error) {
+	// TODO Get SessionKey from Cache
+	var sessionKey *crypto.SessionKey = nil
+
+	if sessionKey != nil {
+		message, err := c.DecryptMessageWithSessionKey(sessionKey, armoredCiphertext)
+		// If Decrypt was successfull
+		if err == nil {
+			return message, nil
+		}
+		// if this failed, fall through
+	}
+
+	metadata, newSessionKey, err := c.DecryptMessageWithPrivateKeyAndReturnSessionKey(metadataKey, armoredCiphertext)
+	if err != nil {
+		return "", fmt.Errorf("Decrypting Metadata: %w", err)
+	}
+
+	// TODO Save newSessionKey to cache
+	_ = newSessionKey
+
+	return metadata, nil
+}