Merge pull request #2 from arpitchakladar/dev/porting-to-firefox

Dev/implementing OCR for captcha autofill

2 files changed, 108 insertions, 111 deletions

diff --git a/src/scripts/login.ts b/src/scripts/login.ts
deleted file mode 100644
index 0fe5239..0000000
--- a/src/scripts/login.ts
+++ /dev/null
@@ -1,111 +0,0 @@
-import { interceptPost, interceptGet } from "@/shared/intercept-jquery-ajax";
-
-interceptPost("viewLoginAreaAction", args => {
-	const callback = args[1];
-	args[1] = (html: any) => {
-		callback(html);
-		const captchaInputElement = $("#txtCaptcha");
-		const captchaValueElement = $("#txtInput");
-		captchaInputElement.val("FFFFFF");
-		captchaValueElement.val("FFFFFF");
-		(window as any).DrawLoginCaptcha = () => {};
-		(window as any).validateLoginCaptcha = () => true;
-		captchaValueElement.hide();
-		captchaInputElement.hide();
-		$(".captcharefresh").hide();
-	}
-});
-interceptPost("viewPasswordRecoveryArea", args => {
-	const callback = args[1];
-	args[1] = (html: any) => {
-		callback(html);
-		const captchaInputElement = $("#dText");
-		const captchaValueElement = $("#captaText");
-		captchaInputElement.val("FFFFFF");
-		captchaValueElement.val("FFFFFF");
-		(window as any).Captcha = () => {};
-		captchaValueElement.hide();
-		captchaInputElement.hide();
-		$("#captchaRef").hide();
-	}
-});
-interceptPost("login.action", args => {
-	const callback = args[2];
-	args[2] = (data: any) => {
-		const loginData = args[1];
-		if (!data.exception && data.checkmsg === "success") {
-			window.localStorage.setItem("loginData", btoa(JSON.stringify(loginData)));
-		}
-
-		callback(data);
-		$("#txtInput").val("FFFFFF");
-		$("#beforeLoginDiv").hide();
-		$("#afterLoginDiv").css("display", "block");
-		$("#afterLoginLabel").css("display", "block");
-		const username = atob(loginData.username.split("RGxycyMxMjM=")[1]);
-		$("#afterLoginLabel > label").html(`--> ${username}`);
-	};
-});
-interceptPost("changePassword.action", args => {
-	const callback = args[2];
-	args[2] = (data: any) => {
-		callback(data);
-		$("#txtInput").val("FFFFFF");
-	};
-});
-interceptGet("viewRegistrationAreaAction", args => {
-	const callback = args[1];
-	args[1] = (html: any) => {
-		callback(html);
-		const captchaInputElement = $("#regInputCaptcha");
-		const captchaValueElement = $("#regCaptcha");
-		captchaInputElement.val("FFFFFF");
-		captchaValueElement.val("FFFFFF");
-		$("#registrationForm > div > div:nth-child(5) > div:nth-child(3)").hide();
-		$("#registrationForm > div > div:nth-child(5) > div:nth-child(4)").hide();
-		$("#registrationForm > div > div:nth-child(5) > div:nth-child(5)").hide();
-		(window as any).DrawRegistrationCaptcha = () => {};
-		(window as any).validateRegistrationCaptcha = () => true;
-	}
-});
-interceptGet("viewChangePasswordAction", args => {
-	const callback = args[1];
-	args[1] = (html: any) => {
-		callback(html);
-		const captchaValueElement = $("#txtCaptcha");
-		const captchaInputElement = $("#txtInput");
-		captchaValueElement.val("FFFFFF");
-		captchaInputElement.val("FFFFFF");
-		(window as any).DrawLoginCaptcha = () => {};
-		captchaValueElement.hide();
-		captchaInputElement.hide();
-		$(".captcharefresh").hide();
-	}
-});
-
-document.addEventListener("DOMContentLoaded", () => {
-	$("#afterLoginDiv > a").click(() => {
-		window.localStorage.removeItem("loginData");
-	});
-
-	const login = () => {
-		let loginData = window.localStorage.getItem("loginData");
-		loginData = loginData ? JSON.parse(atob(loginData)) : null;
-
-		if (loginData) {
-			$.post(
-				"/BanglarBhumi/login.action",
-				loginData,
-				data => {
-					if (data.exception || data.checkmsg !== "success") {
-						loginData = null;
-					}
-				},
-				"json"
-			);
-		}
-	};
-
-	login();
-	setInterval(login, 1000 * 60);
-});
diff --git a/src/scripts/login/index.ts b/src/scripts/login/index.ts
new file mode 100644
index 0000000..6e459a5
--- /dev/null
+++ b/src/scripts/login/index.ts
@@ -0,0 +1,108 @@
+import { interceptPost, interceptGet } from "@/shared/intercept-jquery-ajax";
+
+function prepareCaptcha(ctx: CanvasRenderingContext2D, width: number, height: number) {
+	const imgData = ctx.getImageData(0, 0, width, height);
+	const data = imgData.data;
+	const radius = 1;
+
+	function isBlack(r: number, g: number, b: number) {
+		return r < 50 && g < 50 && b < 50;
+	}
+
+	function isGrayish(r: number, g: number, b: number) {
+		return Math.abs(r - g) < 15 && Math.abs(g - b) < 15 && r > 100 && r < 200;
+	}
+
+	function hasNearbyBlack(x: number, y: number) {
+		for (let dx = -radius; dx <= radius; dx++) {
+			for (let dy = -radius; dy <= radius; dy++) {
+				const nx = x + dx;
+				const ny = y + dy;
+				if (nx >= 0 && nx < width && ny >= 0 && ny < height) {
+					const i = (ny * width + nx) * 4;
+					if (isBlack(data[i], data[i + 1], data[i + 2])) return true;
+				}
+			}
+		}
+		return false;
+	}
+
+	for (let y = 0; y < height; y++) {
+		for (let x = 0; x < width; x++) {
+			const i = (y * width + x) * 4;
+			const [r, g, b] = [data[i], data[i + 1], data[i + 2]];
+			if (isGrayish(r, g, b) && !hasNearbyBlack(x, y)) {
+				data[i] = data[i + 1] = data[i + 2] = 255;
+			}
+		}
+	}
+	for (let y = 0; y < height; y++) {
+		for (let x = 0; x < width; x++) {
+			const i = (y * width + x) * 4;
+			const [r, g, b] = [data[i], data[i + 1], data[i + 2]];
+
+			if (isGrayish(r, g, b)) {
+				data[i] = data[i + 1] = data[i + 2] = 0; // make black
+			}
+		}
+	}
+	ctx.putImageData(imgData, 0, 0);
+}
+
+const observer = new MutationObserver((mutationsList, obs) => {
+	for (const mutation of mutationsList) {
+		for (const node of mutation.addedNodes) {
+			if ((node as any).nodeType === 1 && (node as any).id === "loginform") {
+				const img = (node as HTMLFormElement).querySelector("#captchaImg") as HTMLImageElement;
+				const captchaInput = (node as HTMLFormElement).querySelector("#txtInput") as HTMLInputElement;
+
+				// Wait for image to load to get correct dimensions
+				img.addEventListener("load", async () => {
+					const { width, height } = img;
+
+					// 1. Create canvas
+					const canvas = document.createElement("canvas");
+					canvas.width = width;
+					canvas.height = height;
+					canvas.style.display = "block";
+
+					// 2. Copy styles (optional)
+					canvas.style.cssText = getComputedStyle(img).cssText;
+					canvas.style.display = "none";
+
+					// 3. Insert canvas before image
+					img.parentNode!.querySelectorAll("canvas").forEach(c => c.remove());
+					img.parentNode!.insertBefore(canvas, img);
+
+					// 4. Hide image
+					img.style.display = "none";
+
+					// 5. Draw the image onto the canvas
+					const ctx = canvas.getContext("2d")!;
+					ctx.drawImage(img, 0, 0);
+					prepareCaptcha(ctx, canvas.width, canvas.height);
+					canvas.style.display = "";
+					const dataURL = canvas.toDataURL("image/png");
+
+					// Perform OCR
+					chrome.runtime.sendMessage(
+						{ type: "OCR", dataURL },
+						({ success, text, confidence }) => {
+							if (success) {
+								if (confidence < 85) {
+									// Reset the captcha if confidence is low
+									img.src = "generateCaptcha?" + new Date().getTime();
+								} else {
+									captchaInput.value = text;
+								}
+							}
+						},
+					);
+				});
+			}
+		}
+	}
+});
+
+// Start observing the body
+observer.observe(document.body, { childList: true, subtree: true });