nip5A: nsites.

nip5a/helpers.go

@@ -0,0 +1,38 @@
+package nip5a
+
+import (
+	"fmt"
+	"math/big"
+	"strings"
+
+	"fiatjaf.com/nostr"
+)
+
+func NormalizePath(p string) string {
+	if !strings.HasSuffix(p, ".html") && !strings.HasSuffix(p, "/") {
+		return p
+	}
+	if strings.HasSuffix(p, "/") {
+		return p + "index.html"
+	}
+	return p
+}
+
+func PubKeyFromBase36(value string) (nostr.PubKey, error) {
+	bi, ok := new(big.Int).SetString(value, 36)
+	if !ok {
+		return nostr.ZeroPK, fmt.Errorf("invalid base36 pubkey")
+	}
+	buf := bi.Bytes()
+	if len(buf) > 32 {
+		return nostr.ZeroPK, fmt.Errorf("base36 pubkey too long")
+	}
+	var pk nostr.PubKey
+	copy(pk[32-len(buf):], buf)
+	return pk, nil
+}
+
+func PubKeyToBase36(pubkey nostr.PubKey) string {
+	value := new(big.Int).SetBytes(pubkey[:]).Text(36)
+	return strings.Repeat("0", 50-len(value)) + value
+}

nip5a/nip5a.go

@@ -0,0 +1,145 @@
+package nip5a
+
+import (
+	"encoding/hex"
+	"fmt"
+	"regexp"
+	"strings"
+	"unsafe"
+
+	"fiatjaf.com/nostr"
+	"fiatjaf.com/nostr/nip19"
+)
+
+type SiteManifest struct {
+	Event       *nostr.Event
+	Pubkey      nostr.PubKey
+	Root        bool
+	Identifier  string
+	Paths       map[string][32]byte
+	Servers     []string
+	Title       string
+	Description string
+	Source      string
+}
+
+func ParseSiteManifest(event *nostr.Event) (*SiteManifest, error) {
+	sm := &SiteManifest{Event: event}
+
+	switch event.Kind {
+	case nostr.KindNsiteRoot:
+		sm.Root = true
+	case nostr.KindNsiteNamed:
+		sm.Root = false
+		for _, tag := range event.Tags {
+			if len(tag) >= 2 && tag[0] == "d" {
+				sm.Identifier = tag[1]
+				break
+			}
+		}
+		if sm.Identifier == "" {
+			return nil, fmt.Errorf("named site manifest missing d tag")
+		}
+	default:
+		return nil, fmt.Errorf("invalid site manifest kind: %d", event.Kind)
+	}
+
+	sm.Pubkey = event.PubKey
+	sm.Paths = make(map[string][32]byte, len(event.Tags))
+
+	for _, tag := range event.Tags {
+		if len(tag) < 2 {
+			continue
+		}
+		switch tag[0] {
+		case "path":
+			var hash [32]byte
+			if len(tag[2]) != 64 {
+				return nil, fmt.Errorf("invalid hash '%s' for path '%s'", tag[2], tag[1])
+			}
+			if _, err := hex.Decode(hash[:], unsafe.Slice(unsafe.StringData(tag[2]), 64)); err != nil {
+				return nil, fmt.Errorf("invalid hash '%s' for path '%s'", tag[2], tag[1])
+			}
+			sm.Paths[NormalizePath(tag[1])] = hash
+		case "server":
+			sm.Servers = append(sm.Servers, tag[1])
+		case "title":
+			sm.Title = tag[1]
+		case "description":
+			sm.Description = tag[1]
+		case "source":
+			sm.Source = tag[1]
+		}
+	}
+
+	return sm, nil
+}
+
+func (sm *SiteManifest) ToEvent(pubkey nostr.PubKey) *nostr.Event {
+	event := &nostr.Event{
+		PubKey:    pubkey,
+		CreatedAt: nostr.Now(),
+		Tags:      nostr.Tags{},
+	}
+
+	if sm.Root {
+		event.Kind = nostr.KindNsiteRoot
+	} else {
+		event.Kind = nostr.KindNsiteNamed
+		event.Tags = append(event.Tags, nostr.Tag{"d", sm.Identifier})
+	}
+
+	for path, hash := range sm.Paths {
+		event.Tags = append(event.Tags, nostr.Tag{"path", NormalizePath(path), hex.EncodeToString(hash[:])})
+	}
+	for _, s := range sm.Servers {
+		event.Tags = append(event.Tags, nostr.Tag{"server", s})
+	}
+	if sm.Title != "" {
+		event.Tags = append(event.Tags, nostr.Tag{"title", sm.Title})
+	}
+	if sm.Description != "" {
+		event.Tags = append(event.Tags, nostr.Tag{"description", sm.Description})
+	}
+	if sm.Source != "" {
+		event.Tags = append(event.Tags, nostr.Tag{"source", sm.Source})
+	}
+
+	return event
+}
+
+//go:inline
+func (sm *SiteManifest) GetHashForPath(path string) ([32]byte, bool) {
+	path = NormalizePath(path)
+	hash, ok := sm.Paths[path]
+	return hash, ok
+}
+
+func DecodeSiteURL(label string) (pubkey nostr.PubKey, identifier string, isRoot bool, err error) {
+	label, _, _ = strings.Cut(label, ".")
+
+	if strings.HasPrefix(label, "npub1") {
+		_, value, err := nip19.Decode(label)
+		if err != nil {
+			return nostr.ZeroPK, "", false, err
+		}
+		return value.(nostr.PubKey), "", true, nil
+	}
+
+	if len(label) < 51 || len(label) > 63 || strings.HasSuffix(label, "-") {
+		return nostr.ZeroPK, "", false, fmt.Errorf("invalid site label format")
+	}
+
+	pubkeyB36 := label[:50]
+	dTag := label[50:]
+	if !regexp.MustCompile(`^[a-z0-9-]{1,13}$`).MatchString(dTag) {
+		return nostr.ZeroPK, "", false, fmt.Errorf("invalid dtag format")
+	}
+
+	pk, err := PubKeyFromBase36(pubkeyB36)
+	if err != nil {
+		return nostr.ZeroPK, "", false, err
+	}
+
+	return pk, dTag, false, nil
+}