2021-12-07 13:18:08 -05:00

105 lines
3.2 KiB
JavaScript

const isObject = require('../help/is_object')
let validateCrit = require('../help/validate_crit')
const { JWSInvalid } = require('../errors')
validateCrit = validateCrit.bind(undefined, JWSInvalid)
const compactSerializer = (payload, [recipient]) => {
return `${recipient.protected}.${payload}.${recipient.signature}`
}
compactSerializer.validate = (jws, { 0: { unprotectedHeader, protectedHeader }, length }) => {
if (length !== 1 || unprotectedHeader) {
throw new JWSInvalid('JWS Compact Serialization doesn\'t support multiple recipients or JWS unprotected headers')
}
validateCrit(protectedHeader, unprotectedHeader, protectedHeader ? protectedHeader.crit : undefined)
}
const flattenedSerializer = (payload, [recipient]) => {
const { header, signature, protected: prot } = recipient
return {
payload,
...prot ? { protected: prot } : undefined,
...header ? { header } : undefined,
signature
}
}
flattenedSerializer.validate = (jws, { 0: { unprotectedHeader, protectedHeader }, length }) => {
if (length !== 1) {
throw new JWSInvalid('Flattened JWS JSON Serialization doesn\'t support multiple recipients')
}
validateCrit(protectedHeader, unprotectedHeader, protectedHeader ? protectedHeader.crit : undefined)
}
const generalSerializer = (payload, recipients) => {
return {
payload,
signatures: recipients.map(({ header, signature, protected: prot }) => {
return {
...prot ? { protected: prot } : undefined,
...header ? { header } : undefined,
signature
}
})
}
}
generalSerializer.validate = (jws, recipients) => {
let validateB64 = false
recipients.forEach(({ protectedHeader, unprotectedHeader }) => {
if (protectedHeader && !validateB64 && 'b64' in protectedHeader) {
validateB64 = true
}
validateCrit(protectedHeader, unprotectedHeader, protectedHeader ? protectedHeader.crit : undefined)
})
if (validateB64) {
const values = recipients.map(({ protectedHeader }) => protectedHeader && protectedHeader.b64)
if (!values.every((actual, i, [expected]) => actual === expected)) {
throw new JWSInvalid('the "b64" Header Parameter value MUST be the same for all recipients')
}
}
}
const isJSON = (input) => {
return isObject(input) && (typeof input.payload === 'string' || Buffer.isBuffer(input.payload))
}
const isValidRecipient = (recipient) => {
return isObject(recipient) && typeof recipient.signature === 'string' &&
(recipient.header === undefined || isObject(recipient.header)) &&
(recipient.protected === undefined || typeof recipient.protected === 'string')
}
const isMultiRecipient = (input) => {
if (Array.isArray(input.signatures) && input.signatures.every(isValidRecipient)) {
return true
}
return false
}
const detect = (input) => {
if (typeof input === 'string' && input.split('.').length === 3) {
return 'compact'
}
if (isJSON(input)) {
if (isMultiRecipient(input)) {
return 'general'
}
if (isValidRecipient(input)) {
return 'flattened'
}
}
throw new JWSInvalid('JWS malformed or invalid serialization')
}
module.exports = {
compact: compactSerializer,
flattened: flattenedSerializer,
general: generalSerializer,
detect
}