nak encrypt and nak decrypt: nip44 with option to do nip04.

closes https://github.com/fiatjaf/nak/issues/36

encrypt_decrypt.go

@@ -0,0 +1,140 @@
+package main
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/fiatjaf/cli/v3"
+	"github.com/nbd-wtf/go-nostr"
+	"github.com/nbd-wtf/go-nostr/nip04"
+)
+
+var encrypt = &cli.Command{
+	Name:                      "encrypt",
+	Usage:                     "encrypts a string with nip44 (or nip04 if specified using a flag) and returns the resulting ciphertext as base64",
+	ArgsUsage:                 "[plaintext string]",
+	DisableSliceFlagSeparator: true,
+	Flags: append(
+		defaultKeyFlags,
+		&cli.StringFlag{
+			Name:     "recipient-pubkey",
+			Aliases:  []string{"p", "tgt", "target", "pubkey"},
+			Required: true,
+		},
+		&cli.BoolFlag{
+			Name:  "nip04",
+			Usage: "use nip04 encryption instead of nip44",
+		},
+	),
+	Action: func(ctx context.Context, c *cli.Command) error {
+		target := c.String("recipient-pubkey")
+		if !nostr.IsValidPublicKey(target) {
+			return fmt.Errorf("target %s is not a valid public key", target)
+		}
+
+		plaintext := c.Args().First()
+
+		if c.Bool("nip04") {
+			sec, bunker, err := gatherSecretKeyOrBunkerFromArguments(ctx, c)
+			if err != nil {
+				return err
+			}
+
+			if bunker != nil {
+				ciphertext, err := bunker.NIP04Encrypt(ctx, target, plaintext)
+				if err != nil {
+					return err
+				}
+				fmt.Println(ciphertext)
+			} else {
+				ss, err := nip04.ComputeSharedSecret(target, sec)
+				if err != nil {
+					return fmt.Errorf("failed to compute nip04 shared secret: %w", err)
+				}
+				ciphertext, err := nip04.Encrypt(plaintext, ss)
+				if err != nil {
+					return fmt.Errorf("failed to encrypt as nip04: %w", err)
+				}
+				fmt.Println(ciphertext)
+			}
+		} else {
+			kr, err := gatherKeyerFromArguments(ctx, c)
+			if err != nil {
+				return err
+			}
+
+			res, err := kr.Encrypt(ctx, plaintext, target)
+			if err != nil {
+				return fmt.Errorf("failed to encrypt: %w", err)
+			}
+			fmt.Println(res)
+		}
+
+		return nil
+	},
+}
+
+var decrypt = &cli.Command{
+	Name:                      "decrypt",
+	Usage:                     "decrypts a base64 nip44 ciphertext (or nip04 if specified using a flag) and returns the resulting plaintext",
+	ArgsUsage:                 "[ciphertext base64]",
+	DisableSliceFlagSeparator: true,
+	Flags: append(
+		defaultKeyFlags,
+		&cli.StringFlag{
+			Name:     "sender-pubkey",
+			Aliases:  []string{"p", "src", "source", "pubkey"},
+			Required: true,
+		},
+		&cli.BoolFlag{
+			Name:  "nip04",
+			Usage: "use nip04 encryption instead of nip44",
+		},
+	),
+	Action: func(ctx context.Context, c *cli.Command) error {
+		source := c.String("sender-pubkey")
+		if !nostr.IsValidPublicKey(source) {
+			return fmt.Errorf("source %s is not a valid public key", source)
+		}
+
+		ciphertext := c.Args().First()
+
+		if c.Bool("nip04") {
+			sec, bunker, err := gatherSecretKeyOrBunkerFromArguments(ctx, c)
+			if err != nil {
+				return err
+			}
+
+			if bunker != nil {
+				plaintext, err := bunker.NIP04Decrypt(ctx, source, ciphertext)
+				if err != nil {
+					return err
+				}
+				fmt.Println(plaintext)
+			} else {
+				ss, err := nip04.ComputeSharedSecret(source, sec)
+				if err != nil {
+					return fmt.Errorf("failed to compute nip04 shared secret: %w", err)
+				}
+				plaintext, err := nip04.Decrypt(ciphertext, ss)
+				if err != nil {
+					return fmt.Errorf("failed to encrypt as nip04: %w", err)
+				}
+				fmt.Println(plaintext)
+			}
+		} else {
+			kr, err := gatherKeyerFromArguments(ctx, c)
+			if err != nil {
+				return err
+			}
+
+			res, err := kr.Decrypt(ctx, ciphertext, source)
+			if err != nil {
+				return fmt.Errorf("failed to encrypt: %w", err)
+			}
+			fmt.Println(res)
+		}
+
+		return nil
+	},
+}