exposure-keys/dist/ExposureKeys.js

Temporary Exposure Keys (TEK) library

import { loadAsync } from 'jszip';
import { TemporaryExposureKeyExport, TEKSignatureList } from '../proto/export';
function isZip(fileContent) {
    // eslint-disable-next-line no-magic-numbers
    const zipHeader = [0x50, 0x4b];
    return Buffer.from(zipHeader).compare(fileContent, 0, 2) === 0;
}
export async function loadZip(fileContent) {
    var _a, _b;
    if (!isZip(fileContent)) {
        throw new Error('The file you are trying to load is not a zip file.');
    }
    const unzippedData = await loadAsync(fileContent);
    const keyData = await ((_a = unzippedData.file('export.bin')) === null || _a === void 0 ? void 0 : _a.async('nodebuffer'));
    const signatureData = await ((_b = unzippedData.file('export.sig')) === null || _b === void 0 ? void 0 : _b.async('nodebuffer'));
    if (!keyData) {
        throw new Error(`The zip file doesn't contain key data`);
    }
    if (!signatureData) {
        throw new Error(`The zip file doesn't contain a signature`);
    }
    return { keys: keyData, signature: signatureData };
}
export function loadKeys(fileContent) {
    if (isZip(fileContent)) {
        throw new Error('You are trying to load a zip file. Please use `loadZip()` for that');
    }
    const wantedHeader = 'EK Export v1    ';
    const header = fileContent.slice(0, wantedHeader.length);
    const key = fileContent.slice(wantedHeader.length);
    if (header.toString('utf-8') !== wantedHeader) {
        throw new Error('The key is missing a correct header');
    }
    return TemporaryExposureKeyExport.decode(key);
}
export function loadSignature(fileContent) {
    return TEKSignatureList.decode(fileContent);
}
export function riskCount(temporaryExposureKeyExport, transmissionRiskLevel) {
    return temporaryExposureKeyExport.keys.filter(key => key.transmissionRiskLevel && key.transmissionRiskLevel === transmissionRiskLevel).length;
}