YARA-913

src/captcha/captcha.service.ts

@@ -0,0 +1,42 @@
+import { Injectable } from "@nestjs/common";
+import * as svgCaptcha from "svg-captcha";
+
+export interface GeneratedCaptcha {
+  text: string;
+  image: string;
+  expiresAt: number;
+}
+
+@Injectable()
+export class CaptchaService {
+  generate(): GeneratedCaptcha {
+    const captcha = svgCaptcha.create({
+      size: 5,
+      ignoreChars: "0oO1ilI",
+      noise: 3,
+      color: true,
+      background: "#f8fafc",
+      width: 160,
+      height: 56,
+      fontSize: 52,
+    });
+
+    return {
+      text: captcha.text,
+      image: `data:image/svg+xml;base64,${Buffer.from(captcha.data, "utf8").toString("base64")}`,
+      expiresAt: this.buildExpireAt(),
+    };
+  }
+
+  normalizeAnswer(input: string): string {
+    return input.trim().toLowerCase();
+  }
+
+  buildExpireAt(): number {
+    const raw = Number(
+      process.env.EXP_CAPTCHA_TIME ?? process.env.EXP_OTP_TIME ?? "2",
+    );
+    const minutes = Number.isFinite(raw) && raw > 0 ? raw : 2;
+    return Date.now() + minutes * 60 * 1000;
+  }
+}