29 lines
1.1 KiB
JavaScript
29 lines
1.1 KiB
JavaScript
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"use strict"
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Object.defineProperty(exports, "__esModule", { value: true })
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const ALLOWED_TOKENS = new Set(["no-referrer", "no-referrer-when-downgrade", "same-origin", "origin", "strict-origin", "origin-when-cross-origin", "strict-origin-when-cross-origin", "unsafe-url", ""])
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function getHeaderValueFromOptions({ policy = ["no-referrer"] }) {
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const tokens = typeof policy === "string" ? [policy] : policy
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if (tokens.length === 0) {
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throw new Error("Referrer-Policy received no policy tokens")
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}
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const tokensSeen = new Set()
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tokens.forEach(token => {
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if (!ALLOWED_TOKENS.has(token)) {
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throw new Error(`Referrer-Policy received an unexpected policy token ${JSON.stringify(token)}`)
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} else if (tokensSeen.has(token)) {
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throw new Error(`Referrer-Policy received a duplicate policy token ${JSON.stringify(token)}`)
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}
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tokensSeen.add(token)
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})
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return tokens.join(",")
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}
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function referrerPolicy(options = {}) {
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const headerValue = getHeaderValueFromOptions(options)
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return function referrerPolicyMiddleware(_req, res, next) {
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res.setHeader("Referrer-Policy", headerValue)
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next()
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}
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}
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module.exports = referrerPolicy
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exports.default = referrerPolicy
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