1 files changed, 56 insertions, 0 deletions
diff --git a/packages/anastasis-webui/src/pages/home/authMethodSetup/totp.ts b/packages/anastasis-webui/src/pages/home/authMethodSetup/totp.ts
new file mode 100644
index 000000000..0bc3feaf8
--- /dev/null
+++ b/packages/anastasis-webui/src/pages/home/authMethodSetup/totp.ts
@@ -0,0 +1,56 @@
+/* eslint-disable @typescript-eslint/camelcase */
+import jssha from 'jssha'
+
+const SEARCH_RANGE = 16
+const timeStep = 30
+
+export function computeTOTPandCheck(secretKey: Uint8Array, digits: number, code: number): boolean {
+  const now = new Date().getTime()
+  const epoch = Math.floor(Math.round(now / 1000.0) / timeStep);
+
+  for (let ms = -SEARCH_RANGE; ms < SEARCH_RANGE; ms++) {
+    const movingFactor = (epoch + ms).toString(16).padStart(16, "0");
+
+    const hmacSha = new jssha('SHA-1', 'HEX', { hmacKey: { value: secretKey, format: 'UINT8ARRAY' } });
+    hmacSha.update(movingFactor);
+    const hmac_text = hmacSha.getHMAC('UINT8ARRAY');
+
+    const offset = (hmac_text[hmac_text.length - 1] & 0xf)
+
+    const otp = ((
+      (hmac_text[offset + 0] << 24) +
+      (hmac_text[offset + 1] << 16) +
+      (hmac_text[offset + 2] << 8) +
+      (hmac_text[offset + 3])
+    ) & 0x7fffffff) % Math.pow(10, digits)
+
+    if (otp == code) return true
+  }
+  return false
+}
+
+const encTable__ = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567".split('')
+export function base32enc(buffer: Uint8Array): string {
+  let rpos = 0
+  let bits = 0
+  let vbit = 0
+
+  let result = ""
+  while ((rpos < buffer.length) || (vbit > 0)) {
+    if ((rpos < buffer.length) && (vbit < 5)) {
+      bits = (bits << 8) | buffer[rpos++];
+      vbit += 8;
+    }
+    if (vbit < 5) {
+      bits <<= (5 - vbit);
+      vbit = 5;
+    }
+    result += encTable__[(bits >> (vbit - 5)) & 31];
+    vbit -= 5;
+  }
+  return result
+}
+
+// const array = new Uint8Array(256)
+// const secretKey = window.crypto.getRandomValues(array)
+// console.log(base32enc(secretKey))