Merge pull request #15 from whs-authz-authn-project/feature/pkce
PKCE 리팩토링 && pkceCheckController는 onInterceptRequest에서 작동되어야합니다.
This commit is contained in:
암냥 (imnyang)
GitHub
commit
e83988f5fb
2 changed files with 93 additions and 97 deletions
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@ -2,138 +2,94 @@ import type { SDK } from "caido:plugin";
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import { Body, RequestSpec, type Request } from "caido:utils";
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export class PKCECheck {
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// 필요한 PKCE 파라미터 목록
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private readonly requiredPKCEKeys = ["client_id", "response_type", "code_challenge", "code_challenge_method"];
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// PKCE 취약점 테스트 메인 함수
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async test(sdk: SDK, req: Request): Promise<boolean> {
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const method = req.getMethod();
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const url = req.getUrl();
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// GET 요청이 아니면 검사하지 않음
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if (method !== "GET") {
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sdk.console.log("[PKCEDowngradeCheck] Not a GET request. Skipping.");
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return false;
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}
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const query = req.getQuery();
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const searchParams = new URLSearchParams(query);
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const requiredKeys = ["client_id", "response_type", "code_challenge", "code_challenge_method"];
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const searchParams = new URLSearchParams(req.getQuery());
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if (!requiredKeys.every((key) => searchParams.has(key))) {
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// 필수 PKCE 파라미터들이 모두 있는지 확인
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if (!this.requiredPKCEKeys.every(key => searchParams.has(key))) {
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sdk.console.log("[PKCEDowngradeCheck] Required PKCE parameters missing. Skipping.");
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return false;
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}
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const url = req.getUrl();
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// OpenID 여부 확인
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const isOpenID = searchParams.get("scope")?.includes("openid") || url.includes("id_token");
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const methodVal = searchParams.get("code_challenge_method");
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const challengeVal = searchParams.get("code_challenge");
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// 파라미터가 없으면 경고 리포트 생성
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if (!methodVal || !challengeVal) {
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sdk.console.log("[PKCEDowngradeCheck] code_challenge or method missing. Skipping.");
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await sdk.findings.create({
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title: isOpenID
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? "[WARN] OpenID Flow PKCE Parameters Missing"
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: "[WARN] OAuth2 Flow PKCE Parameters Missing",
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description: `PKCE parameters are missing or incomplete for ${url}. This may indicate a misconfiguration.`,
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request: req,
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reporter: "PKCE Checker",
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});
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await this.reportFinding(sdk, req, url, isOpenID, "[WARN] PKCE Parameters Missing", "PKCE parameters are missing or incomplete.");
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return false;
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}
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// code_challenge_method가 'plain'이면 취약할 수 있음
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if (methodVal === "plain") {
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sdk.console.log("[PKCEDowngradeCheck] code_challenge_method is 'plain'. Skipping.");
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await sdk.findings.create({
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title: isOpenID
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? "[WARN] OpenID Flow PKCE Method is 'plain'"
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: "[WARN] OAuth2 Flow PKCE Method is 'plain'",
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description: `PKCE method is set to 'plain' for ${url}. This may indicate a downgrade vulnerability.`,
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request: req,
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reporter: "PKCE Checker",
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});
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await this.reportFinding(sdk, req, url, isOpenID, "[WARN] PKCE Method is 'plain'", "PKCE method is set to 'plain'. This may indicate a downgrade vulnerability.");
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return false;
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}
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// Remove PKCE parameters to simulate a downgraded request
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// PKCE 관련 파라미터 제거하여 다운그레이드된 URL 생성
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searchParams.delete("code_challenge");
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searchParams.delete("code_challenge_method");
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const downgradedQuery = searchParams.toString();
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const scheme = req.getUrl().startsWith("https") ? "https" : "http";
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const scheme = url.startsWith("https") ? "https" : "http";
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const downgradedUrl = `${scheme}://${req.getHost()}:${req.getPort()}${req.getPath()}?${downgradedQuery}`;
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sdk.console.log(`${req.getHost()} Original URL: ` + url);
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sdk.console.log(`${req.getHost()} Downgraded URL: ` + downgradedUrl);
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sdk.console.log(`${req.getHost()} Original URL: ${url}`);
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sdk.console.log(`${req.getHost()} Downgraded URL: ${downgradedUrl}`);
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try {
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// Use Caido Replay SDK to replay the original request
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const spec = new RequestSpec(downgradedUrl);
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spec.setBody(req.getBody() as Body);
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for (const [key, value] of Object.entries(req.getHeaders())) {
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if (Array.isArray(value)) {
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spec.setHeader(key, value.join(', ')); // or another suitable delimiter
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} else {
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spec.setHeader(key, value);
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}
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}
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spec.setHost(req.getHost());
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spec.setMethod(req.getMethod());
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spec.setPath(req.getPath());
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spec.setQuery(downgradedQuery);
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spec.setTls(req.getTls());
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spec.setPort(req.getPort());
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// 원래 요청과 다운그레이드된 요청 각각 전송
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const downgradedResponse = await this.sendRequest(sdk, req, downgradedUrl, downgradedQuery);
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const originalResponse = await this.sendRequest(sdk, req, url, req.getQuery());
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let sendDowngradedRequest = await sdk.requests.send(spec);
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if (downgradedResponse && originalResponse) {
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const originalCode = originalResponse.getCode();
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const downgradedCode = downgradedResponse.getCode();
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if (sendDowngradedRequest.response) {
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let domain = spec.getHost();
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let port = spec.getPort();
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let path = spec.getPath();
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let query = spec.getQuery();
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let id = sendDowngradedRequest.response.getId();
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let code = sendDowngradedRequest.response.getCode();
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sdk.console.log(`REQ ${id}: ${domain}:${port}${path}${query} received a status code of ${code}`);
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}
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const originalLoc = originalResponse.getHeader("location") || "";
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const downgradedLoc = downgradedResponse.getHeader("location") || "";
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if (sendDowngradedRequest.response?.getCode() === 302) {
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await sdk.findings.create({
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title: isOpenID
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? "[CRITICAL] OpenID Flow PKCE Downgrade Vulnerability"
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: "[CRITICAL] OAuth2 Flow PKCE Downgrade Vulnerability",
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description: `The request to ${url} is vulnerable to a PKCE downgrade attack. This may indicate a configuration error.`,
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request: req,
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reporter: "PKCE Checker",
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});
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}
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sdk.console.log(`${req.getHost()} Original Status: ${originalCode}`);
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sdk.console.log(`${req.getHost()} Downgraded Status: ${downgradedCode}`);
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sdk.console.log(`${req.getHost()} Original Location: ${originalLoc}`);
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sdk.console.log(`${req.getHost()} Downgraded Location: ${downgradedLoc}`);
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/*
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sdk.console.log(`${req.getHost()} Original Status: ` + resOriginal.status);
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sdk.console.log(`${req.getHost()} Downgraded Status: ` + resDowngraded.status);
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// 두 응답 모두 리디렉션이면서 code= 파라미터 포함 시 취약점 리포트 생성
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const bothRedirect = [301, 302].includes(originalCode) && [301, 302].includes(downgradedCode);
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const bothContainCode = originalLoc.includes("code=") && downgradedLoc.includes("code=");
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sdk.console.log(`${req.getHost()} Original Headers: ` + JSON.stringify(resOriginal.headers));
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sdk.console.log(`${req.getHost()} Downgraded Headers: ` + JSON.stringify(resDowngraded.headers));
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// Caido Dev Docs 기준으로, 리다이렉트된 URL은 Response 객체의 url 속성에 저장되어 있음
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const locationOriginal = resOriginal.url ?? "";
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const locationDowngraded = resDowngraded.url ?? "";
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sdk.console.log(`${req.getHost()} Original Location: ` + locationOriginal);
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sdk.console.log(`${req.getHost()} Downgraded Location: ` + locationDowngraded);
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const statusEqual = resOriginal.status === resDowngraded.status;
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const codeInRedirects = locationOriginal.includes("code=") && locationDowngraded.includes("code=");
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if (statusEqual && codeInRedirects) {
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if (bothRedirect && bothContainCode) {
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const title = isOpenID
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? "[CRITICAL] OpenID Flow PKCE Downgraded to Plaintext"
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: "[CRITICAL] OAuth2 Flow PKCE Downgraded to Plaintext";
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? "[CRITICAL] OpenID Flow PKCE Downgrade Vulnerability"
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: "[CRITICAL] OAuth2 Flow PKCE Downgrade Vulnerability";
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const reference = isOpenID
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? "https://openid.net/specs/openid-igov-oauth2-1_0-02.html#rfc.section.3.1.7"
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: "https://datatracker.ietf.org/doc/html/rfc7636";
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await sdk.findings.create({
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title,
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description: `PKCE downgrade detected for ${url}.\n\nDowngraded URL: ${downgradedUrl}\n\nRedirect contained code=.\n\nReference: ${reference}`,
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description: `PKCE downgrade vulnerability detected!\n\nOriginal URL: ${url}\nDowngraded URL: ${downgradedUrl}\n\nBoth requests returned authorization codes, indicating the server accepts requests without PKCE protection.\n\nReference: ${reference}`,
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request: req,
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reporter: "",
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reporter: "PKCE Checker",
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});
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return true;
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}*/
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}
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}
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} catch (err) {
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sdk.console.error(`PKCE downgrade check failed for ${url}: ${String(err)}`);
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}
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@ -141,4 +97,41 @@ export class PKCECheck {
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sdk.console.log("[PKCEDowngradeCheck] No PKCE downgrade detected.");
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return false;
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}
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// 요청 전송 도우미 함수
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private async sendRequest(sdk: SDK, req: Request, url: string, query: string) {
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const spec = new RequestSpec(url);
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spec.setMethod(req.getMethod());
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spec.setPath(req.getPath());
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spec.setQuery(query);
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spec.setBody(req.getBody() as Body);
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spec.setHost(req.getHost());
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spec.setPort(req.getPort());
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spec.setTls(req.getTls());
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for (const [key, value] of Object.entries(req.getHeaders())) {
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spec.setHeader(key, Array.isArray(value) ? value.join(', ') : value);
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}
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const result = await sdk.requests.send(spec);
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return result.response ?? null;
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}
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// 경고 리포트 생성 함수
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private async reportFinding(
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sdk: SDK,
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req: Request,
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url: string,
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isOpenID: boolean,
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title: string,
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message: string
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) {
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const fullTitle = isOpenID ? `[WARN] OpenID Flow ${title}` : `[WARN] OAuth2 Flow ${title}`;
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await sdk.findings.create({
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title: fullTitle,
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description: `${message} (${url})`,
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request: req,
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reporter: "PKCE Checker",
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});
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}
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}
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@ -19,7 +19,7 @@ const ScopeDetectionController = new ScopeDetection();
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export function init(sdk: SDK<API>) {
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sdk.events.onInterceptResponse(async (sdk, req: Request, res: Response) => {
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await csrfCheck.checker(sdk, req, res);
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await pkceCheckController.test(sdk, req);
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//await pkceCheckController.test(sdk, req);
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await tokenCheck.testReq(sdk, req);
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await tokenCheck.testResp(sdk, res, req);
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await ScopeDetectionController.scan(sdk, req.getUrl());
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@ -34,6 +34,9 @@ export function init(sdk: SDK<API>) {
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// }
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});
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sdk.events.onInterceptRequest(async (sdk, req: Request) => {
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await pkceCheckController.test(sdk, req);
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});
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/*
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sdk.events.onInterceptRequest(async (sdk, req: Request) => {
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const result =
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