feat: add Nostr channel plugin and onboarding install defaults

Co-authored-by: joelklabo <joelklabo@users.noreply.github.com>

extensions/nostr/src/nostr-profile-import.ts

@@ -0,0 +1,259 @@
+/**
+ * Nostr Profile Import
+ *
+ * Fetches and verifies kind:0 profile events from relays.
+ * Used to import existing profiles before editing.
+ */
+
+import { SimplePool, verifyEvent, type Event } from "nostr-tools";
+
+import { contentToProfile, type ProfileContent } from "./nostr-profile.js";
+import type { NostrProfile } from "./config-schema.js";
+import { validateUrlSafety } from "./nostr-profile-http.js";
+
+// ============================================================================
+// Types
+// ============================================================================
+
+export interface ProfileImportResult {
+  /** Whether the import was successful */
+  ok: boolean;
+  /** The imported profile (if found and valid) */
+  profile?: NostrProfile;
+  /** The raw event (for advanced users) */
+  event?: {
+    id: string;
+    pubkey: string;
+    created_at: number;
+  };
+  /** Error message if import failed */
+  error?: string;
+  /** Which relays responded */
+  relaysQueried: string[];
+  /** Which relay provided the winning event */
+  sourceRelay?: string;
+}
+
+export interface ProfileImportOptions {
+  /** The public key to fetch profile for */
+  pubkey: string;
+  /** Relay URLs to query */
+  relays: string[];
+  /** Timeout per relay in milliseconds (default: 5000) */
+  timeoutMs?: number;
+}
+
+// ============================================================================
+// Constants
+// ============================================================================
+
+const DEFAULT_TIMEOUT_MS = 5000;
+
+// ============================================================================
+// Profile Import
+// ============================================================================
+
+/**
+ * Sanitize URLs in an imported profile to prevent SSRF attacks.
+ * Removes any URLs that don't pass SSRF validation.
+ */
+function sanitizeProfileUrls(profile: NostrProfile): NostrProfile {
+  const result = { ...profile };
+  const urlFields = ["picture", "banner", "website"] as const;
+
+  for (const field of urlFields) {
+    const value = result[field];
+    if (value && typeof value === "string") {
+      const validation = validateUrlSafety(value);
+      if (!validation.ok) {
+        // Remove unsafe URL
+        delete result[field];
+      }
+    }
+  }
+
+  return result;
+}
+
+/**
+ * Fetch the latest kind:0 profile event for a pubkey from relays.
+ *
+ * - Queries all relays in parallel
+ * - Takes the event with the highest created_at
+ * - Verifies the event signature
+ * - Parses and returns the profile
+ */
+export async function importProfileFromRelays(
+  opts: ProfileImportOptions
+): Promise<ProfileImportResult> {
+  const { pubkey, relays, timeoutMs = DEFAULT_TIMEOUT_MS } = opts;
+
+  if (!pubkey || !/^[0-9a-fA-F]{64}$/.test(pubkey)) {
+    return {
+      ok: false,
+      error: "Invalid pubkey format (must be 64 hex characters)",
+      relaysQueried: [],
+    };
+  }
+
+  if (relays.length === 0) {
+    return {
+      ok: false,
+      error: "No relays configured",
+      relaysQueried: [],
+    };
+  }
+
+  const pool = new SimplePool();
+  const relaysQueried: string[] = [];
+
+  try {
+    // Query all relays for kind:0 events from this pubkey
+    const events: Array<{ event: Event; relay: string }> = [];
+
+    // Create timeout promise
+    const timeoutPromise = new Promise<void>((resolve) => {
+      setTimeout(resolve, timeoutMs);
+    });
+
+    // Create subscription promise
+    const subscriptionPromise = new Promise<void>((resolve) => {
+      let completed = 0;
+
+      for (const relay of relays) {
+        relaysQueried.push(relay);
+
+        const sub = pool.subscribeMany(
+          [relay],
+          [
+            {
+              kinds: [0],
+              authors: [pubkey],
+              limit: 1,
+            },
+          ],
+          {
+            onevent(event) {
+              events.push({ event, relay });
+            },
+            oneose() {
+              completed++;
+              if (completed >= relays.length) {
+                resolve();
+              }
+            },
+            onclose() {
+              completed++;
+              if (completed >= relays.length) {
+                resolve();
+              }
+            },
+          }
+        );
+
+        // Clean up subscription after timeout
+        setTimeout(() => {
+          sub.close();
+        }, timeoutMs);
+      }
+    });
+
+    // Wait for either all relays to respond or timeout
+    await Promise.race([subscriptionPromise, timeoutPromise]);
+
+    // No events found
+    if (events.length === 0) {
+      return {
+        ok: false,
+        error: "No profile found on any relay",
+        relaysQueried,
+      };
+    }
+
+    // Find the event with the highest created_at (newest wins for replaceable events)
+    let bestEvent: { event: Event; relay: string } | null = null;
+    for (const item of events) {
+      if (!bestEvent || item.event.created_at > bestEvent.event.created_at) {
+        bestEvent = item;
+      }
+    }
+
+    if (!bestEvent) {
+      return {
+        ok: false,
+        error: "No valid profile event found",
+        relaysQueried,
+      };
+    }
+
+    // Verify the event signature
+    const isValid = verifyEvent(bestEvent.event);
+    if (!isValid) {
+      return {
+        ok: false,
+        error: "Profile event has invalid signature",
+        relaysQueried,
+        sourceRelay: bestEvent.relay,
+      };
+    }
+
+    // Parse the profile content
+    let content: ProfileContent;
+    try {
+      content = JSON.parse(bestEvent.event.content) as ProfileContent;
+    } catch {
+      return {
+        ok: false,
+        error: "Profile event has invalid JSON content",
+        relaysQueried,
+        sourceRelay: bestEvent.relay,
+      };
+    }
+
+    // Convert to our profile format
+    const profile = contentToProfile(content);
+
+    // Sanitize URLs from imported profile to prevent SSRF when auto-merging
+    const sanitizedProfile = sanitizeProfileUrls(profile);
+
+    return {
+      ok: true,
+      profile: sanitizedProfile,
+      event: {
+        id: bestEvent.event.id,
+        pubkey: bestEvent.event.pubkey,
+        created_at: bestEvent.event.created_at,
+      },
+      relaysQueried,
+      sourceRelay: bestEvent.relay,
+    };
+  } finally {
+    pool.close(relays);
+  }
+}
+
+/**
+ * Merge imported profile with local profile.
+ *
+ * Strategy:
+ * - For each field, prefer local if set, otherwise use imported
+ * - This preserves user customizations while filling in missing data
+ */
+export function mergeProfiles(
+  local: NostrProfile | undefined,
+  imported: NostrProfile | undefined
+): NostrProfile {
+  if (!imported) return local ?? {};
+  if (!local) return imported;
+
+  return {
+    name: local.name ?? imported.name,
+    displayName: local.displayName ?? imported.displayName,
+    about: local.about ?? imported.about,
+    picture: local.picture ?? imported.picture,
+    banner: local.banner ?? imported.banner,
+    website: local.website ?? imported.website,
+    nip05: local.nip05 ?? imported.nip05,
+    lud16: local.lud16 ?? imported.lud16,
+  };
+}