Initial commit

ui/crypto.js

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+// Sshwifty - A Web SSH client
+//
+// Copyright (C) 2019 Rui NI <nirui@gmx.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as
+// published by the Free Software Foundation, either version 3 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+/**
+ * Generate HMAC 512 of given data
+ *
+ * @param {Uint8Array} secret Secret key
+ * @param {Uint8Array} data Data to be HMAC'ed
+ */
+export async function hmac512(secret, data) {
+  const key = await crypto.subtle.importKey(
+    "raw",
+    secret,
+    {
+      name: "HMAC",
+      hash: { name: "SHA-512" }
+    },
+    false,
+    ["sign", "verify"]
+  );
+
+  return crypto.subtle.sign("HMAC", key, data);
+}
+
+export const GCMNonceSize = 12;
+
+/**
+ * Build AES GCM Encryption/Decryption key
+ *
+ * @param {Uint8Array} keyData Key data
+ */
+export function buildGCMKey(keyData) {
+  return crypto.subtle.importKey("raw", keyData, "aes-gcm", false, [
+    "encrypt",
+    "decrypt"
+  ]);
+}
+
+/**
+ * Encrypt data
+ *
+ * @param {CryptoKey} key Key
+ * @param {Uint8Array} iv Nonce
+ * @param {Uint8Array} plaintext Data to be encrypted
+ */
+export function encryptGCM(key, iv, plaintext) {
+  return crypto.subtle.encrypt({ name: "aes-gcm", iv: iv }, key, plaintext);
+}
+
+/**
+ * Decrypt data
+ *
+ * @param {CryptoKey} key Key
+ * @param {Uint8Array} iv Nonce
+ * @param {Uint8Array} cipherText Data to be decrypted
+ */
+export function decryptGCM(key, iv, cipherText) {
+  return crypto.subtle.decrypt({ name: "aes-gcm", iv: iv }, key, cipherText);
+}
+
+/**
+ * generate Random nonce
+ *
+ */
+export function generateNonce() {
+  return crypto.getRandomValues(new Uint8Array(GCMNonceSize));
+}
+
+/**
+ * Increase nonce by one
+ *
+ * @param {Uint8Array} nonce Nonce data
+ *
+ * @returns {Uint8Array} New nonce
+ *
+ */
+export function increaseNonce(nonce) {
+  for (let i = nonce.length; i > 0; i--) {
+    nonce[i - 1]++;
+
+    if (nonce[i - 1] <= 0) {
+      continue;
+    }
+
+    break;
+  }
+
+  return nonce;
+}