nak verify

README.md

@@ -70,3 +70,9 @@ publishing to wss://eden.nostr.land... failed: msg: blocked: not on white-list
 publishing to wss://atlas.nostr.land... failed: msg: blocked: not on white-list
 publishing to wss://relayable.org... success.
 ```
+
+### verify if an event is good
+```shell
+~> echo '{"content":"hello world","created_at":1698923350,"id":"05bd99d54cb835f327e0092c4275ee44c7ff51219eff417c19f70c9e2c53ad5a","kind":1,"pubkey":"79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798","sig":"0a04a296321ed933858577f36fb2fb9a0933e966f9ee32b539493f5a4d00120891b1ca9152ebfbc04fb403bdaa7c73f415e7c4954e55726b4b4fa8cebf008cd6","tags":[]}' | nak verify
+invalid .id, expected 05bd99d54cb835f427e0092c4275ee44c7ff51219eff417c19f70c9e2c53ad5a, got 05bd99d54cb835f327e0092c4275ee44c7ff51219eff417c19f70c9e2c53ad5a
+```

main.go

@@ -18,6 +18,7 @@ func main() {
 			event,
 			decode,
 			encode,
+			verify,
 		},
 	}
 

verify.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+
+	"github.com/nbd-wtf/go-nostr"
+	"github.com/urfave/cli/v2"
+)
+
+var verify = &cli.Command{
+	Name:  "verify",
+	Usage: "checks the hash and signature of an event given through stdin",
+	Description: `example:
+		echo '{"id":"a889df6a387419ff204305f4c2d296ee328c3cd4f8b62f205648a541b4554dfb","pubkey":"c6047f9441ed7d6d3045406e95c07cd85c778e4b8cef3ca7abac09b95c709ee5","created_at":1698623783,"kind":1,"tags":[],"content":"hello from the nostr army knife","sig":"84876e1ee3e726da84e5d195eb79358b2b3eaa4d9bd38456fde3e8a2af3f1cd4cda23f23fda454869975b3688797d4c66e12f4c51c1b43c6d2997c5e61865661"}' | nak verify
+
+it outputs nothing if the verification is successful.
+`,
+	Action: func(c *cli.Context) error {
+		evt := nostr.Event{}
+		if stdinEvent := getStdin(); stdinEvent != "" {
+			if err := json.Unmarshal([]byte(stdinEvent), &evt); err != nil {
+				return fmt.Errorf("invalid JSON: %w", err)
+			}
+		}
+
+		if evt.GetID() != evt.ID {
+			return fmt.Errorf("invalid .id, expected %s, got %s", evt.GetID(), evt.ID)
+		}
+
+		if ok, err := evt.CheckSignature(); !ok {
+			return fmt.Errorf("invalid signature: %w", err)
+		}
+
+		return nil
+	},
+}