Add node modules and compiled JavaScript from main (#54)

Co-authored-by: Oliver King <oking3@uncc.edu>

node_modules/jose/lib/help/validate_crit.js

@@ -0,0 +1,41 @@
+const { JOSECritNotUnderstood, JWSInvalid } = require('../errors')
+
+const DEFINED = new Set([
+  'alg', 'jku', 'jwk', 'kid', 'x5u', 'x5c', 'x5t', 'x5t#S256', 'typ', 'cty',
+  'crit', 'enc', 'zip', 'epk', 'apu', 'apv', 'iv', 'tag', 'p2s', 'p2c'
+])
+
+module.exports = function validateCrit (Err, protectedHeader, unprotectedHeader, understood) {
+  if (protectedHeader && 'crit' in protectedHeader) {
+    if (
+      !Array.isArray(protectedHeader.crit) ||
+      protectedHeader.crit.length === 0 ||
+      protectedHeader.crit.some(s => typeof s !== 'string' || !s)
+    ) {
+      throw new Err('"crit" Header Parameter MUST be an array of non-empty strings when present')
+    }
+    const whitelisted = new Set(understood)
+    const combined = { ...protectedHeader, ...unprotectedHeader }
+    protectedHeader.crit.forEach((parameter) => {
+      if (DEFINED.has(parameter)) {
+        throw new Err(`The critical list contains a non-extension Header Parameter ${parameter}`)
+      }
+      if (!whitelisted.has(parameter)) {
+        throw new JOSECritNotUnderstood(`critical "${parameter}" is not understood`)
+      }
+      if (parameter === 'b64') {
+        if (!('b64' in protectedHeader)) {
+          throw new JWSInvalid('"b64" critical parameter must be integrity protected')
+        }
+        if (typeof protectedHeader.b64 !== 'boolean') {
+          throw new JWSInvalid('"b64" critical parameter must be a boolean')
+        }
+      } else if (!(parameter in combined)) {
+        throw new Err(`critical parameter "${parameter}" is missing`)
+      }
+    })
+  }
+  if (unprotectedHeader && 'crit' in unprotectedHeader) {
+    throw new Err('"crit" Header Parameter MUST be integrity protected when present')
+  }
+}