keyring -> keyer, fix misunderstanding with NIP-59 and adjust api.

keyer/lib.go

@@ -0,0 +1,90 @@
+package keyer
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/nbd-wtf/go-nostr"
+	"github.com/nbd-wtf/go-nostr/nip05"
+	"github.com/nbd-wtf/go-nostr/nip19"
+	"github.com/nbd-wtf/go-nostr/nip46"
+	"github.com/nbd-wtf/go-nostr/nip49"
+)
+
+type Keyer interface {
+	Signer
+	Cipher
+}
+
+// A Signer provides basic public key signing methods.
+type Signer interface {
+	GetPublicKey(context.Context) string
+	SignEvent(context.Context, *nostr.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)
+}
+
+type SignerOptions struct {
+	BunkerClientSecretKey string
+	BunkerSignTimeout     time.Duration
+	BunkerAuthHandler     func(string)
+
+	// if a PasswordHandler is provided the key will be stored encrypted and this function will be called
+	// every time an operation needs access to the key so the user can be prompted.
+	PasswordHandler func(context.Context) string
+
+	// if instead a Password is provided along with a ncryptsec, then the key will be decrypted and stored in plaintext.
+	Password string
+}
+
+func New(ctx context.Context, pool *nostr.SimplePool, input string, opts *SignerOptions) (Keyer, error) {
+	if opts == nil {
+		opts = &SignerOptions{}
+	}
+
+	if strings.HasPrefix(input, "ncryptsec") {
+		if opts.PasswordHandler != nil {
+			return &EncryptedKeySigner{input, "", opts.PasswordHandler}, nil
+		}
+		sec, err := nip49.Decrypt(input, opts.Password)
+		if err != nil {
+			if opts.Password == "" {
+				return nil, fmt.Errorf("failed to decrypt with blank password: %w", err)
+			}
+			return nil, fmt.Errorf("failed to decrypt with given password: %w", err)
+		}
+		pk, _ := nostr.GetPublicKey(sec)
+		return KeySigner{sec, pk, make(map[string][32]byte)}, nil
+	} else if nip46.IsValidBunkerURL(input) || nip05.IsValidIdentifier(input) {
+		bcsk := nostr.GeneratePrivateKey()
+		oa := func(url string) { println("auth_url received but not handled") }
+
+		if opts.BunkerClientSecretKey != "" {
+			bcsk = opts.BunkerClientSecretKey
+		}
+		if opts.BunkerAuthHandler != nil {
+			oa = opts.BunkerAuthHandler
+		}
+
+		bunker, err := nip46.ConnectBunker(ctx, bcsk, input, pool, oa)
+		if err != nil {
+			return nil, err
+		}
+		return BunkerSigner{bunker}, nil
+	} else if prefix, parsed, err := nip19.Decode(input); err == nil && prefix == "nsec" {
+		sec := parsed.(string)
+		pk, _ := nostr.GetPublicKey(sec)
+		return KeySigner{sec, pk, make(map[string][32]byte)}, nil
+	} else if nostr.IsValid32ByteHex(input) {
+		pk, _ := nostr.GetPublicKey(input)
+		return KeySigner{input, pk, make(map[string][32]byte)}, nil
+	}
+
+	return nil, fmt.Errorf("unsupported input '%s'", input)
+}