keyer: move interfaces to toplevel "nostr" package.

keyer.go

@@ -0,0 +1,20 @@
+package nostr
+
+import "context"
+
+type Keyer interface {
+	Signer
+	Cipher
+}
+
+// A Signer provides basic public key signing methods.
+type Signer interface {
+	GetPublicKey(context.Context) (string, error)
+	SignEvent(context.Context, *Event) error
+}
+
+// A Cipher provides NIP-44 encryption and decryption methods.
+type Cipher interface {
+	Encrypt(ctx context.Context, plaintext string, recipientPublicKey string) (base64ciphertext string, err error)
+	Decrypt(ctx context.Context, base64ciphertext string, senderPublicKey string) (plaintext string, err error)
+}