implement auth, closed and close envelopes

pkg/encoders/event/canonical.go

@@ -0,0 +1,36 @@
+package event
+
+import (
+	"next.orly.dev/pkg/crypto/sha256"
+	"next.orly.dev/pkg/encoders/hex"
+	"next.orly.dev/pkg/encoders/ints"
+	"next.orly.dev/pkg/encoders/text"
+)
+
+// ToCanonical converts the event to the canonical encoding used to derive the
+// event ID.
+func (ev *E) ToCanonical(dst []byte) (b []byte) {
+	b = dst
+	b = append(b, "[0,\""...)
+	b = hex.EncAppend(b, ev.Pubkey)
+	b = append(b, "\","...)
+	b = ints.New(ev.CreatedAt).Marshal(nil)
+	b = append(b, ',')
+	b = ints.New(ev.Kind).Marshal(nil)
+	b = append(b, ',')
+	b = ev.Tags.Marshal(b)
+	b = append(b, ',')
+	b = text.AppendQuote(b, ev.Content, text.NostrEscape)
+	b = append(b, ']')
+	return
+}
+
+// GetIDBytes returns the raw SHA256 hash of the canonical form of an event.E.
+func (ev *E) GetIDBytes() []byte { return Hash(ev.ToCanonical(nil)) }
+
+// Hash is a little helper generate a hash and return a slice instead of an
+// array.
+func Hash(in []byte) (out []byte) {
+	h := sha256.Sum256(in)
+	return h[:]
+}