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

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

node_modules/jose/lib/jwa/ecdh/kw.js

@@ -0,0 +1,47 @@
+const { improvedDH } = require('../../help/runtime_support')
+const { KEYOBJECT } = require('../../help/consts')
+const { generateSync } = require('../../jwk/generate')
+const { ECDH_DERIVE_LENGTHS } = require('../../registry')
+
+const derive = require('./derive')
+
+const wrapKey = (wrap, derive, key, payload) => {
+  const epk = generateSync(key.kty, key.crv)
+
+  const derivedKey = derive(epk, key, payload)
+
+  const result = wrap({ [KEYOBJECT]: derivedKey }, payload)
+  result.header = result.header || {}
+  Object.assign(result.header, { epk: { kty: key.kty, crv: key.crv, x: epk.x, y: epk.y } })
+
+  return result
+}
+
+const unwrapKey = (unwrap, derive, key, payload, header) => {
+  const { epk } = header
+  const derivedKey = derive(key, epk, header)
+
+  return unwrap({ [KEYOBJECT]: derivedKey }, payload, header)
+}
+
+module.exports = (JWA, JWK) => {
+  ['ECDH-ES+A128KW', 'ECDH-ES+A192KW', 'ECDH-ES+A256KW'].forEach((jwaAlg) => {
+    const kw = jwaAlg.substr(-6)
+    const kwWrap = JWA.keyManagementEncrypt.get(kw)
+    const kwUnwrap = JWA.keyManagementDecrypt.get(kw)
+    const keylen = parseInt(jwaAlg.substr(9, 3), 10)
+    ECDH_DERIVE_LENGTHS.set(jwaAlg, keylen)
+
+    if (kwWrap && kwUnwrap) {
+      JWA.keyManagementEncrypt.set(jwaAlg, wrapKey.bind(undefined, kwWrap, derive.bind(undefined, jwaAlg, keylen)))
+      JWA.keyManagementDecrypt.set(jwaAlg, unwrapKey.bind(undefined, kwUnwrap, derive.bind(undefined, jwaAlg, keylen)))
+      JWK.EC.deriveKey[jwaAlg] = key => (key.use === 'enc' || key.use === undefined) && key.crv !== 'secp256k1'
+
+      if (improvedDH) {
+        JWK.OKP.deriveKey[jwaAlg] = key => (key.use === 'enc' || key.use === undefined) && key.keyObject.asymmetricKeyType.startsWith('x')
+      }
+    }
+  })
+}
+module.exports.wrapKey = wrapKey
+module.exports.unwrapKey = unwrapKey