1 files changed, 252 insertions, 0 deletions
diff --git a/backend/node_modules/jwa/index.js b/backend/node_modules/jwa/index.js
new file mode 100644
index 0000000..e71e6d1
--- /dev/null
+++ b/backend/node_modules/jwa/index.js
@@ -0,0 +1,252 @@
+var bufferEqual = require('buffer-equal-constant-time');
+var Buffer = require('safe-buffer').Buffer;
+var crypto = require('crypto');
+var formatEcdsa = require('ecdsa-sig-formatter');
+var util = require('util');
+
+var MSG_INVALID_ALGORITHM = '"%s" is not a valid algorithm.\n  Supported algorithms are:\n  "HS256", "HS384", "HS512", "RS256", "RS384", "RS512", "PS256", "PS384", "PS512", "ES256", "ES384", "ES512" and "none".'
+var MSG_INVALID_SECRET = 'secret must be a string or buffer';
+var MSG_INVALID_VERIFIER_KEY = 'key must be a string or a buffer';
+var MSG_INVALID_SIGNER_KEY = 'key must be a string, a buffer or an object';
+
+var supportsKeyObjects = typeof crypto.createPublicKey === 'function';
+if (supportsKeyObjects) {
+  MSG_INVALID_VERIFIER_KEY += ' or a KeyObject';
+  MSG_INVALID_SECRET += 'or a KeyObject';
+}
+
+function checkIsPublicKey(key) {
+  if (Buffer.isBuffer(key)) {
+    return;
+  }
+
+  if (typeof key === 'string') {
+    return;
+  }
+
+  if (!supportsKeyObjects) {
+    throw typeError(MSG_INVALID_VERIFIER_KEY);
+  }
+
+  if (typeof key !== 'object') {
+    throw typeError(MSG_INVALID_VERIFIER_KEY);
+  }
+
+  if (typeof key.type !== 'string') {
+    throw typeError(MSG_INVALID_VERIFIER_KEY);
+  }
+
+  if (typeof key.asymmetricKeyType !== 'string') {
+    throw typeError(MSG_INVALID_VERIFIER_KEY);
+  }
+
+  if (typeof key.export !== 'function') {
+    throw typeError(MSG_INVALID_VERIFIER_KEY);
+  }
+};
+
+function checkIsPrivateKey(key) {
+  if (Buffer.isBuffer(key)) {
+    return;
+  }
+
+  if (typeof key === 'string') {
+    return;
+  }
+
+  if (typeof key === 'object') {
+    return;
+  }
+
+  throw typeError(MSG_INVALID_SIGNER_KEY);
+};
+
+function checkIsSecretKey(key) {
+  if (Buffer.isBuffer(key)) {
+    return;
+  }
+
+  if (typeof key === 'string') {
+    return key;
+  }
+
+  if (!supportsKeyObjects) {
+    throw typeError(MSG_INVALID_SECRET);
+  }
+
+  if (typeof key !== 'object') {
+    throw typeError(MSG_INVALID_SECRET);
+  }
+
+  if (key.type !== 'secret') {
+    throw typeError(MSG_INVALID_SECRET);
+  }
+
+  if (typeof key.export !== 'function') {
+    throw typeError(MSG_INVALID_SECRET);
+  }
+}
+
+function fromBase64(base64) {
+  return base64
+    .replace(/=/g, '')
+    .replace(/\+/g, '-')
+    .replace(/\//g, '_');
+}
+
+function toBase64(base64url) {
+  base64url = base64url.toString();
+
+  var padding = 4 - base64url.length % 4;
+  if (padding !== 4) {
+    for (var i = 0; i < padding; ++i) {
+      base64url += '=';
+    }
+  }
+
+  return base64url
+    .replace(/\-/g, '+')
+    .replace(/_/g, '/');
+}
+
+function typeError(template) {
+  var args = [].slice.call(arguments, 1);
+  var errMsg = util.format.bind(util, template).apply(null, args);
+  return new TypeError(errMsg);
+}
+
+function bufferOrString(obj) {
+  return Buffer.isBuffer(obj) || typeof obj === 'string';
+}
+
+function normalizeInput(thing) {
+  if (!bufferOrString(thing))
+    thing = JSON.stringify(thing);
+  return thing;
+}
+
+function createHmacSigner(bits) {
+  return function sign(thing, secret) {
+    checkIsSecretKey(secret);
+    thing = normalizeInput(thing);
+    var hmac = crypto.createHmac('sha' + bits, secret);
+    var sig = (hmac.update(thing), hmac.digest('base64'))
+    return fromBase64(sig);
+  }
+}
+
+function createHmacVerifier(bits) {
+  return function verify(thing, signature, secret) {
+    var computedSig = createHmacSigner(bits)(thing, secret);
+    return bufferEqual(Buffer.from(signature), Buffer.from(computedSig));
+  }
+}
+
+function createKeySigner(bits) {
+ return function sign(thing, privateKey) {
+    checkIsPrivateKey(privateKey);
+    thing = normalizeInput(thing);
+    // Even though we are specifying "RSA" here, this works with ECDSA
+    // keys as well.
+    var signer = crypto.createSign('RSA-SHA' + bits);
+    var sig = (signer.update(thing), signer.sign(privateKey, 'base64'));
+    return fromBase64(sig);
+  }
+}
+
+function createKeyVerifier(bits) {
+  return function verify(thing, signature, publicKey) {
+    checkIsPublicKey(publicKey);
+    thing = normalizeInput(thing);
+    signature = toBase64(signature);
+    var verifier = crypto.createVerify('RSA-SHA' + bits);
+    verifier.update(thing);
+    return verifier.verify(publicKey, signature, 'base64');
+  }
+}
+
+function createPSSKeySigner(bits) {
+  return function sign(thing, privateKey) {
+    checkIsPrivateKey(privateKey);
+    thing = normalizeInput(thing);
+    var signer = crypto.createSign('RSA-SHA' + bits);
+    var sig = (signer.update(thing), signer.sign({
+      key: privateKey,
+      padding: crypto.constants.RSA_PKCS1_PSS_PADDING,
+      saltLength: crypto.constants.RSA_PSS_SALTLEN_DIGEST
+    }, 'base64'));
+    return fromBase64(sig);
+  }
+}
+
+function createPSSKeyVerifier(bits) {
+  return function verify(thing, signature, publicKey) {
+    checkIsPublicKey(publicKey);
+    thing = normalizeInput(thing);
+    signature = toBase64(signature);
+    var verifier = crypto.createVerify('RSA-SHA' + bits);
+    verifier.update(thing);
+    return verifier.verify({
+      key: publicKey,
+      padding: crypto.constants.RSA_PKCS1_PSS_PADDING,
+      saltLength: crypto.constants.RSA_PSS_SALTLEN_DIGEST
+    }, signature, 'base64');
+  }
+}
+
+function createECDSASigner(bits) {
+  var inner = createKeySigner(bits);
+  return function sign() {
+    var signature = inner.apply(null, arguments);
+    signature = formatEcdsa.derToJose(signature, 'ES' + bits);
+    return signature;
+  };
+}
+
+function createECDSAVerifer(bits) {
+  var inner = createKeyVerifier(bits);
+  return function verify(thing, signature, publicKey) {
+    signature = formatEcdsa.joseToDer(signature, 'ES' + bits).toString('base64');
+    var result = inner(thing, signature, publicKey);
+    return result;
+  };
+}
+
+function createNoneSigner() {
+  return function sign() {
+    return '';
+  }
+}
+
+function createNoneVerifier() {
+  return function verify(thing, signature) {
+    return signature === '';
+  }
+}
+
+module.exports = function jwa(algorithm) {
+  var signerFactories = {
+    hs: createHmacSigner,
+    rs: createKeySigner,
+    ps: createPSSKeySigner,
+    es: createECDSASigner,
+    none: createNoneSigner,
+  }
+  var verifierFactories = {
+    hs: createHmacVerifier,
+    rs: createKeyVerifier,
+    ps: createPSSKeyVerifier,
+    es: createECDSAVerifer,
+    none: createNoneVerifier,
+  }
+  var match = algorithm.match(/^(RS|PS|ES|HS)(256|384|512)$|^(none)$/i);
+  if (!match)
+    throw typeError(MSG_INVALID_ALGORITHM, algorithm);
+  var algo = (match[1] || match[3]).toLowerCase();
+  var bits = match[2];
+
+  return {
+    sign: signerFactories[algo](bits),
+    verify: verifierFactories[algo](bits),
+  }
+};