"use strict";
/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.dev/license
 */
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    if (k2 === undefined) k2 = k;
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      desc = { enumerable: true, get: function() { return m[k]; } };
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}) : (function(o, m, k, k2) {
    if (k2 === undefined) k2 = k;
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    Object.defineProperty(o, "default", { enumerable: true, value: v });
}) : function(o, v) {
    o["default"] = v;
});
var __importStar = (this && this.__importStar) || (function () {
    var ownKeys = function(o) {
        ownKeys = Object.getOwnPropertyNames || function (o) {
            var ar = [];
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        __setModuleDefault(result, mod);
        return result;
    };
})();
Object.defineProperty(exports, "__esModule", { value: true });
exports.hashTextContent = hashTextContent;
exports.autoCsp = autoCsp;
const crypto = __importStar(require("node:crypto"));
const html_rewriting_stream_1 = require("./html-rewriting-stream");
/**
 * The hash function to use for hash directives to use in the CSP.
 */
const HASH_FUNCTION = 'sha256';
/**
 * Get the specified attribute or return undefined if the tag doesn't have that attribute.
 *
 * @param tag StartTag of the <script>
 * @returns
 */
function getScriptAttributeValue(tag, attrName) {
    return tag.attrs.find((attr) => attr.name === attrName)?.value;
}
/**
 * Checks whether a particular string is a MIME type associated with JavaScript, according to
 * https://developer.mozilla.org/en-US/docs/Web/HTTP/MIME_types#textjavascript
 *
 * @param mimeType a string that may be a MIME type
 * @returns whether the string is a MIME type that is associated with JavaScript
 */
function isJavascriptMimeType(mimeType) {
    return mimeType.split(';')[0] === 'text/javascript';
}
/**
 * Which of the type attributes on the script tag we should try passing along
 * based on https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script/type
 * @param scriptType the `type` attribute on the `<script>` tag under question
 * @returns whether to add the script tag to the dynamically loaded script tag
 */
function shouldDynamicallyLoadScriptTagBasedOnType(scriptType) {
    return (scriptType === undefined ||
        scriptType === '' ||
        scriptType === 'module' ||
        isJavascriptMimeType(scriptType));
}
/**
 * Calculates a CSP compatible hash of an inline script.
 * @param scriptText Text between opening and closing script tag. Has to
 *     include whitespaces and newlines!
 * @returns The hash of the text formatted appropriately for CSP.
 */
function hashTextContent(scriptText) {
    const hash = crypto.createHash(HASH_FUNCTION).update(scriptText, 'utf-8').digest('base64');
    return `'${HASH_FUNCTION}-${hash}'`;
}
/**
 * Finds all `<script>` tags and creates a dynamic script loading block for consecutive `<script>` with `src` attributes.
 * Hashes all scripts, both inline and generated dynamic script loading blocks.
 * Inserts a `<meta>` tag at the end of the `<head>` of the document with the generated hash-based CSP.
 *
 * @param html Markup that should be processed.
 * @returns The transformed HTML that contains the `<meta>` tag CSP and dynamic loader scripts.
 */
async function autoCsp(html, unsafeEval = false) {
    const { rewriter, transformedContent } = await (0, html_rewriting_stream_1.htmlRewritingStream)(html);
    let openedScriptTag = undefined;
    let scriptContent = [];
    const hashes = [];
    /**
     * Generates the dynamic loading script and puts it in the rewriter and adds the hash of the dynamic
     * loader script to the collection of hashes to add to the <meta> tag CSP.
     */
    function emitLoaderScript() {
        const loaderScript = createLoaderScript(scriptContent, /* enableTrustedTypes = */ false);
        hashes.push(hashTextContent(loaderScript));
        rewriter.emitRaw(`<script>${loaderScript}</script>`);
        scriptContent = [];
    }
    rewriter.on('startTag', (tag) => {
        if (tag.tagName === 'script') {
            openedScriptTag = tag;
            const src = getScriptAttributeValue(tag, 'src');
            if (src) {
                // If there are any interesting attributes, note them down.
                const scriptType = getScriptAttributeValue(tag, 'type');
                if (shouldDynamicallyLoadScriptTagBasedOnType(scriptType)) {
                    scriptContent.push({
                        src: src,
                        type: scriptType,
                        async: getScriptAttributeValue(tag, 'async') !== undefined,
                        defer: getScriptAttributeValue(tag, 'defer') !== undefined,
                    });
                    return; // Skip writing my script tag until we've read it all.
                }
            }
        }
        // We are encountering the first start tag that's not <script src="..."> after a string of
        // consecutive <script src="...">. <script> tags without a src attribute will also end a chain
        // of src attributes that can be loaded in a single loader script, so those will end up here.
        //
        // The first place when we can determine this to be the case is
        // during the first opening tag that's not <script src="...">, where we need to insert the
        // dynamic loader script before continuing on with writing the rest of the tags.
        // (One edge case is where there are no more opening tags after the last <script src="..."> is
        // closed, but this case is handled below with the final </body> tag.)
        if (scriptContent.length > 0) {
            emitLoaderScript();
        }
        rewriter.emitStartTag(tag);
    });
    rewriter.on('text', (tag, html) => {
        if (openedScriptTag && !getScriptAttributeValue(openedScriptTag, 'src')) {
            hashes.push(hashTextContent(html));
        }
        rewriter.emitText(tag);
    });
    rewriter.on('endTag', (tag, html) => {
        if (openedScriptTag && tag.tagName === 'script') {
            const src = getScriptAttributeValue(openedScriptTag, 'src');
            const scriptType = getScriptAttributeValue(openedScriptTag, 'type');
            openedScriptTag = undefined;
            // Return early to avoid writing the closing </script> tag if it's a part of the
            // dynamic loader script.
            if (src && shouldDynamicallyLoadScriptTagBasedOnType(scriptType)) {
                return;
            }
        }
        if (tag.tagName === 'head' || tag.tagName === 'body' || tag.tagName === 'html') {
            // Write the loader script if a string of <script>s were the last opening tag of the document.
            if (scriptContent.length > 0) {
                emitLoaderScript();
            }
        }
        rewriter.emitEndTag(tag);
    });
    const rewritten = await transformedContent();
    // Second pass to add the header
    const secondPass = await (0, html_rewriting_stream_1.htmlRewritingStream)(rewritten);
    secondPass.rewriter.on('startTag', (tag, _) => {
        secondPass.rewriter.emitStartTag(tag);
        if (tag.tagName === 'head') {
            // See what hashes we came up with!
            secondPass.rewriter.emitRaw(`<meta http-equiv="Content-Security-Policy" content="${getStrictCsp(hashes, {
                enableBrowserFallbacks: true,
                enableTrustedTypes: false,
                enableUnsafeEval: unsafeEval,
            })}">`);
        }
    });
    return secondPass.transformedContent();
}
/**
 * Returns a strict Content Security Policy for mitigating XSS.
 * For more details read csp.withgoogle.com.
 * If you modify this CSP, make sure it has not become trivially bypassable by
 * checking the policy using csp-evaluator.withgoogle.com.
 *
 * @param hashes A list of sha-256 hashes of trusted inline scripts.
 * @param enableTrustedTypes If Trusted Types should be enabled for scripts.
 * @param enableBrowserFallbacks If fallbacks for older browsers should be
 *   added. This is will not weaken the policy as modern browsers will ignore
 *   the fallbacks.
 * @param enableUnsafeEval If you cannot remove all uses of eval(), you can
 *   still set a strict CSP, but you will have to use the 'unsafe-eval'
 *   keyword which will make your policy slightly less secure.
 */
function getStrictCsp(hashes, 
// default CSP options
cspOptions = {
    enableBrowserFallbacks: true,
    enableTrustedTypes: false,
    enableUnsafeEval: false,
}) {
    hashes = hashes || [];
    const strictCspTemplate = {
        // 'strict-dynamic' allows hashed scripts to create new scripts.
        'script-src': [`'strict-dynamic'`, ...hashes],
        // Restricts `object-src` to disable dangerous plugins like Flash.
        'object-src': [`'none'`],
        // Restricts `base-uri` to block the injection of `<base>` tags. This
        // prevents attackers from changing the locations of scripts loaded from
        // relative URLs.
        'base-uri': [`'self'`],
    };
    // Adds fallbacks for browsers not compatible to CSP3 and CSP2.
    // These fallbacks are ignored by modern browsers in presence of hashes,
    // and 'strict-dynamic'.
    if (cspOptions.enableBrowserFallbacks) {
        // Fallback for Safari. All modern browsers supporting strict-dynamic will
        // ignore the 'https:' fallback.
        strictCspTemplate['script-src'].push('https:');
        // 'unsafe-inline' is only ignored in presence of a hash or nonce.
        if (hashes.length > 0) {
            strictCspTemplate['script-src'].push(`'unsafe-inline'`);
        }
    }
    // If enabled, dangerous DOM sinks will only accept typed objects instead of
    // strings.
    if (cspOptions.enableTrustedTypes) {
        strictCspTemplate['require-trusted-types-for'] = ['script'];
    }
    // If enabled, `eval()`-calls will be allowed, making the policy slightly
    // less secure.
    if (cspOptions.enableUnsafeEval) {
        strictCspTemplate['script-src'].push(`'unsafe-eval'`);
    }
    return Object.entries(strictCspTemplate)
        .map(([directive, values]) => {
        return `${directive} ${values.join(' ')};`;
    })
        .join('');
}
/**
 * Returns JS code for dynamically loading sourced (external) scripts.
 * @param srcList A list of paths for scripts that should be loaded.
 */
function createLoaderScript(srcList, enableTrustedTypes = false) {
    if (!srcList.length) {
        throw new Error('Cannot create a loader script with no scripts to load.');
    }
    const srcListFormatted = srcList
        .map((s) => {
        // URI encoding means value can't escape string, JS, or HTML context.
        const srcAttr = encodeURI(s.src).replaceAll("'", "\\'");
        // Can only be 'module' or a JS MIME type or an empty string.
        const typeAttr = s.type ? "'" + s.type + "'" : "''";
        const asyncAttr = s.async ? 'true' : 'false';
        const deferAttr = s.defer ? 'true' : 'false';
        return `['${srcAttr}', ${typeAttr}, ${asyncAttr}, ${deferAttr}]`;
    })
        .join();
    return enableTrustedTypes
        ? `
  var scripts = [${srcListFormatted}];
  var policy = self.trustedTypes && self.trustedTypes.createPolicy ?
    self.trustedTypes.createPolicy('angular#auto-csp', {createScriptURL: function(u) {
      return scripts.includes(u) ? u : null;
    }}) : { createScriptURL: function(u) { return u; } };
  scripts.forEach(function(scriptUrl) {
    var s = document.createElement('script');
    s.src = policy.createScriptURL(scriptUrl[0]);
    s.type = scriptUrl[1];
    s.async = !!scriptUrl[2];
    s.defer = !!scriptUrl[3];
    document.lastElementChild.appendChild(s);
  });\n`
        : `
  var scripts = [${srcListFormatted}];
  scripts.forEach(function(scriptUrl) {
    var s = document.createElement('script');
    s.src = scriptUrl[0];
    s.type = scriptUrl[1];
    s.async = !!scriptUrl[2];
    s.defer = !!scriptUrl[3];
    document.lastElementChild.appendChild(s);
  });\n`;
}
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