const regex = /e[yw][A-Za-z0-9-_]+\.(?:e[yw][A-Za-z0-9-_]+)?\.[A-Za-z0-9-_]{2,}(?:(?:\.[A-Za-z0-9-_]{2,}){2})?/g;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('e[yw][A-Za-z0-9-_]+\\.(?:e[yw][A-Za-z0-9-_]+)?\\.[A-Za-z0-9-_]{2,}(?:(?:\\.[A-Za-z0-9-_]{2,}){2})?', 'g')
const str = `JWT pattern
- handles both JWS (3 segments) and JWE (5 segments)
- remove the ending \`(?:(?:...\` to handle JWS only
- segments 1+2 are expected tp start with \`e[yw]\`, an encoded start of JSON object \`{"\` or \`{\\n\`
- remove/extend it to match used token structure
- or make it even more restrictive \`(ey[IJ]|ewo)\` to match encoded \`{"\\w\` or \`{\\n"\`
- payload (2nd segment) may be empty
- both header (1st segment) and payload are expected to start with \`eyJ\`, a base64 encoded start of JSON object \`{"\`
- accepts only proper Base64url encoding (RFC 4648) without Base64 padding \`=\`
- test it at https://regex101.com/r/V99DS0
eyJhbGciOiJkaXIiLCJlbmMiOiJBMjU2Q0JDLUhTNTEyIiwia2lkIjoicEw1NGdLalBHWElQVWw3eGlGN3B5MExJY3IxNkhPVlZnTXBtWjZqZmFUcUppb1h6M0FSM21EaWpTdXFxNnNvSTBoM1BaNzdMdDUzRjVUbVVPRW5KRGcifQ..LxFPkpn8Gu8vFuXDtOKA1A.DkMr_qOgv6zdyFiZGnz01wnFfLLmoMpRA-L3EbmgOGv21E-yU8ks7C_MSwA6E8KpXAB7XHeejJQWvs5ZrxDM2G8_t_BIJ6DUFXvLvLOzdo0hceeCCtujAgMPsjxW0RQFHkrA2VOlpuF7vVgJXPby19t0_QBWIaZnpfnAYzDJ98UpO1WbNxqGfdpbNG6RETpH.w1H3V7eGynuOi2qJUooceTCvoC4P5sT7bQRqbLZuyR0`;
// Reset `lastIndex` if this regex is defined globally
// regex.lastIndex = 0;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions