New Captcha Package added

2026-07-25 13:38:18 +05:30
parent d0aded0392
commit 8b728a3e5d
157 changed files with 12092 additions and 1913 deletions
@@ -0,0 +1,63 @@
+import type {
+  CaptchaPolicyOptions,
+  CaptchaRiskResult,
+  CaptchaRiskSignals,
+} from "./types.ts";
+
+export function evaluateCaptchaRisk(
+  signals: CaptchaRiskSignals,
+  threshold = 50,
+): CaptchaRiskResult {
+  let score = Math.max(0, Math.min(100, signals.customScore ?? 0));
+  const reasons: string[] = [];
+  const add = (points: number, reason: string): void => {
+    score = Math.min(100, score + points);
+    reasons.push(reason);
+  };
+  if ((signals.failedAttempts ?? 0) > 0) add(Math.min(35, (signals.failedAttempts ?? 0) * 10), "failed-attempts");
+  if ((signals.requestsInWindow ?? 0) > 20) add(Math.min(35, ((signals.requestsInWindow ?? 0) - 20) * 2), "request-rate");
+  if (signals.completionMs !== undefined && signals.completionMs < 700) add(25, "too-fast");
+  if (signals.missingBrowserSignals) add(20, "missing-browser-signals");
+  if (signals.suspiciousHeaders) add(20, "suspicious-headers");
+  if (signals.tokenReuse) add(70, "token-reuse");
+  if (signals.knownBadIp) add(60, "known-bad-ip");
+  return { score, challenge: score >= threshold, reasons };
+}
+
+export function shouldRequireCaptcha(
+  action: string,
+  options: CaptchaPolicyOptions = {},
+  signals: CaptchaRiskSignals = {},
+): CaptchaRiskResult {
+  if (options.neverForActions?.includes(action) || options.mode === "never") {
+    return { score: 0, challenge: false, reasons: ["policy-never"] };
+  }
+  if (options.alwaysForActions?.includes(action) || options.mode === "always") {
+    return { score: 100, challenge: true, reasons: ["policy-always"] };
+  }
+  if ((options.mode ?? "adaptive") === "session") {
+    return { score: 100, challenge: true, reasons: ["session-unverified"] };
+  }
+  return evaluateCaptchaRisk(signals, options.threshold ?? 50);
+}
+
+export interface CaptchaSessionGrant {
+  action: string;
+  routeGroup?: string;
+  expiresAt: number;
+  provider: string;
+}
+
+export function validCaptchaGrant(
+  grants: CaptchaSessionGrant[] | undefined,
+  action: string,
+  now: number,
+  routeGroup?: string,
+): CaptchaSessionGrant | undefined {
+  return grants?.find(
+    (grant) =>
+      grant.expiresAt > now &&
+      (grant.action === action || grant.action === "*") &&
+      (!routeGroup || !grant.routeGroup || grant.routeGroup === routeGroup),
+  );
+}