Merge pull request #1774 from PR0M3TH3AN/codex/add-helper-to-extract-btih-from-magnets

Add BTIH extraction helper and normalize infohash handling

js/app.js

@@ -13,7 +13,7 @@ import {
   ALLOW_NSFW_CONTENT,
 } from "./config.js";
 import { accessControl } from "./accessControl.js";
-import { safeDecodeMagnet } from "./magnetUtils.js";
+import { extractBtihFromMagnet, safeDecodeMagnet } from "./magnetUtils.js";
 import { deriveTorrentPlaybackConfig } from "./playbackUtils.js";
 import {
   URL_FIRST_ENABLED,
@@ -8571,9 +8571,9 @@ class Application {
       typeof video.infoHash === "string" ? video.infoHash.trim().toLowerCase() : "";
     const fallbackMagnetForCandidate = fallbackMagnetCandidate || "";
     if (!legacyInfoHash && fallbackMagnetForCandidate) {
-      const match = fallbackMagnetForCandidate.match(/xt=urn:btih:([0-9a-z]+)/i);
-      if (match && match[1]) {
-        legacyInfoHash = match[1].toLowerCase();
+      const extracted = extractBtihFromMagnet(fallbackMagnetForCandidate);
+      if (extracted) {
+        legacyInfoHash = extracted;
       }
     }
 

js/magnetShared.js

@@ -5,9 +5,11 @@ import {
 } from "./utils/safeDecode.js";
 
 const HEX_INFO_HASH = /^[0-9a-f]{40}$/i;
+const BASE32_INFO_HASH = /^[a-z2-7]{32}$/i;
 const BTIH_PREFIX = "urn:btih:";
 const MAGNET_SCHEME = "magnet:";
 const ENCODED_BTih_PATTERN = /xt=urn%3Abtih%3A([0-9a-z]+)/gi;
+const BASE32_ALPHABET = "abcdefghijklmnopqrstuvwxyz234567";
 
 export function safeDecodeMagnet(value) {
   if (typeof value !== "string") {
@@ -56,6 +58,96 @@ export function normalizeForComparison(value) {
   }
 }
 
+function decodeBase32ToHex(value) {
+  if (typeof value !== "string" || !value) {
+    return "";
+  }
+
+  const normalized = value.toLowerCase();
+  let bits = 0;
+  let buffer = 0;
+  const bytes = [];
+
+  for (const char of normalized) {
+    const index = BASE32_ALPHABET.indexOf(char);
+    if (index === -1) {
+      return "";
+    }
+    buffer = (buffer << 5) | index;
+    bits += 5;
+    if (bits >= 8) {
+      bits -= 8;
+      const byte = (buffer >> bits) & 0xff;
+      bytes.push(byte);
+    }
+  }
+
+  if (!bytes.length) {
+    return "";
+  }
+
+  return bytes.map((byte) => byte.toString(16).padStart(2, "0")).join("");
+}
+
+export function normalizeInfoHash(value) {
+  const trimmed = typeof value === "string" ? value.trim() : "";
+  if (!trimmed) {
+    return "";
+  }
+  if (HEX_INFO_HASH.test(trimmed)) {
+    return trimmed.toLowerCase();
+  }
+  if (BASE32_INFO_HASH.test(trimmed)) {
+    const hex = decodeBase32ToHex(trimmed);
+    return hex ? hex.toLowerCase() : "";
+  }
+  return "";
+}
+
+function extractInfoHashFromXt(value) {
+  if (typeof value !== "string") {
+    return "";
+  }
+  const trimmed = value.trim();
+  if (!trimmed) {
+    return "";
+  }
+  const lower = trimmed.toLowerCase();
+  if (!lower.startsWith(BTIH_PREFIX)) {
+    return "";
+  }
+  return normalizeInfoHash(trimmed.slice(BTIH_PREFIX.length));
+}
+
+export function extractBtihFromMagnet(rawValue) {
+  const decoded = safeDecodeMagnet(rawValue);
+  const { initial, isMagnet, params } = normalizeMagnetInput(decoded);
+
+  if (!initial) {
+    return "";
+  }
+
+  if (!isMagnet) {
+    if (initial.toLowerCase().startsWith(BTIH_PREFIX)) {
+      return normalizeInfoHash(initial.slice(BTIH_PREFIX.length));
+    }
+    return normalizeInfoHash(initial);
+  }
+
+  for (const param of params) {
+    if (param.lowerKey !== "xt") {
+      continue;
+    }
+    const candidate = param.decoded || param.value;
+    const normalized = extractInfoHashFromXt(candidate);
+    if (normalized) {
+      return normalized;
+    }
+  }
+
+  return "";
+}
+
 function createParam(key, value) {
   const trimmedValue = typeof value === "string" ? value.trim() : "";
   const decoded = safeDecodeURIComponentLoose(trimmedValue);
@@ -342,4 +434,3 @@ export function extractMagnetHints(rawValue) {
   }
   return hints;
 }
-

js/magnetUtils.js

@@ -6,13 +6,17 @@ import {
   ensureTrackers,
   ensureTorrentHint,
   ensureWebSeeds,
+  extractBtihFromMagnet as sharedExtractBtihFromMagnet,
   normalizeMagnetInput,
+  normalizeInfoHash as sharedNormalizeInfoHash,
   resolveAppProtocol,
   safeDecodeMagnet as sharedSafeDecodeMagnet,
 } from "./magnetShared.js";
 
 export { WSS_TRACKERS };
 export const safeDecodeMagnet = sharedSafeDecodeMagnet;
+export const extractBtihFromMagnet = sharedExtractBtihFromMagnet;
+export const normalizeInfoHash = sharedNormalizeInfoHash;
 
 export function normalizeAndAugmentMagnet(
   rawValue,

js/magnets.js

@@ -1,35 +1,4 @@
-const BASE32_ALPHABET = "abcdefghijklmnopqrstuvwxyz234567";
-
-function decodeBase32ToHex(value) {
-  if (typeof value !== "string" || !value) {
-    return "";
-  }
-
-  const normalized = value.toLowerCase();
-  let bits = 0;
-  let buffer = 0;
-  const bytes = [];
-
-  for (const char of normalized) {
-    const index = BASE32_ALPHABET.indexOf(char);
-    if (index === -1) {
-      return "";
-    }
-    buffer = (buffer << 5) | index;
-    bits += 5;
-    if (bits >= 8) {
-      bits -= 8;
-      const byte = (buffer >> bits) & 0xff;
-      bytes.push(byte);
-    }
-  }
-
-  if (bytes.length === 0) {
-    return "";
-  }
-
-  return bytes.map((byte) => byte.toString(16).padStart(2, "0")).join("");
-}
+import { extractBtihFromMagnet, normalizeInfoHash } from "./magnetShared.js";
 
 function extractInfoHashFromXt(value) {
   if (typeof value !== "string") {
@@ -50,32 +19,12 @@ function extractInfoHashFromXt(value) {
   return normalizeInfoHash(payload);
 }
 
-function normalizeInfoHash(candidate) {
-  const trimmed = typeof candidate === "string" ? candidate.trim() : "";
-  if (!trimmed) {
-    return null;
-  }
-  if (/^[0-9a-f]{40}$/i.test(trimmed)) {
-    return trimmed.toLowerCase();
-  }
-  if (/^[a-z2-7]{32}$/i.test(trimmed)) {
-    const hex = decodeBase32ToHex(trimmed);
-    return hex ? hex.toLowerCase() : null;
-  }
-  return null;
-}
-
 export function infoHashFromMagnet(magnet) {
   if (typeof magnet !== "string") {
     return null;
   }
-  const direct = normalizeInfoHash(magnet);
-  if (direct) {
-    return direct;
-  }
-  const parsed = parseMagnetLite(magnet);
-  const hash = typeof parsed.infoHash === "string" ? parsed.infoHash : "";
-  return hash ? hash.toLowerCase() : null;
+  const extracted = extractBtihFromMagnet(magnet);
+  return extracted || null;
 }
 
 export function trackersFromMagnet(magnet) {

js/nostr/nip71.js

@@ -1,5 +1,5 @@
 import { deriveTitleFromEvent } from "../videoEventUtils.js";
-import { extractMagnetHints } from "../magnetShared.js";
+import { extractBtihFromMagnet, extractMagnetHints } from "../magnetShared.js";
 import { devLogger } from "../utils/logger.js";
 import { getCachedNostrTools } from "./toolkit.js";
 
@@ -1432,9 +1432,9 @@ export function convertEventToVideo(event = {}) {
   const originalFileSha256 = normalizeSha256(parsedContent.originalFileSha256);
 
   if (!infoHash && magnet) {
-    const match = magnet.match(/xt=urn:btih:([0-9a-z]+)/i);
-    if (match && match[1]) {
-      pushInfoHash(match[1]);
+    const extracted = extractBtihFromMagnet(magnet);
+    if (extracted) {
+      infoHash = extracted;
     }
   }