47 lines
1.6 KiB
JavaScript
47 lines
1.6 KiB
JavaScript
import derive from './runtime/hkdf.js';
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function normalizeDigest(digest) {
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switch (digest) {
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case 'sha256':
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case 'sha384':
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case 'sha512':
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case 'sha1':
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return digest;
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default:
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throw new TypeError('unsupported "digest" value');
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}
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}
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function normalizeUint8Array(input, label) {
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if (typeof input === 'string')
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return new TextEncoder().encode(input);
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if (!(input instanceof Uint8Array))
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throw new TypeError(`"${label}"" must be an instance of Uint8Array or a string`);
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return input;
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}
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function normalizeIkm(input) {
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const ikm = normalizeUint8Array(input, 'ikm');
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if (!ikm.byteLength)
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throw new TypeError(`"ikm" must be at least one byte in length`);
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return ikm;
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}
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function normalizeInfo(input) {
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const info = normalizeUint8Array(input, 'info');
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if (info.byteLength > 1024) {
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throw TypeError('"info" must not contain more than 1024 bytes');
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}
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return info;
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}
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function normalizeKeylen(input, digest) {
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if (typeof input !== 'number' || !Number.isInteger(input) || input < 1) {
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throw new TypeError('"keylen" must be a positive integer');
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}
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const hashlen = parseInt(digest.substr(3), 10) >> 3 || 20;
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if (input > 255 * hashlen) {
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throw new TypeError('"keylen" too large');
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}
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return input;
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}
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async function hkdf(digest, ikm, salt, info, keylen) {
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return derive(normalizeDigest(digest), normalizeIkm(ikm), normalizeUint8Array(salt, 'salt'), normalizeInfo(info), normalizeKeylen(keylen, digest));
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}
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export { hkdf, hkdf as default };
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