🎉 Initial Commit for the Sphere webpage

DysonNetwork.Sphere/Client/src/views/secure.ts

@@ -0,0 +1,94 @@
+export async function downloadAndDecryptFile(
+  url: string,
+  password: string,
+  fileName: string,
+  onProgress?: (progress: number) => void,
+): Promise<void> {
+  const response = await fetch(url)
+  if (!response.ok) throw new Error(`Failed to fetch: ${response.status}`)
+
+  const contentLength = +(response.headers.get('Content-Length') || 0)
+  const reader = response.body!.getReader()
+  const chunks: Uint8Array[] = []
+  let received = 0
+
+  while (true) {
+    const { done, value } = await reader.read()
+    if (done) break
+    if (value) {
+      chunks.push(value)
+      received += value.length
+      if (contentLength && onProgress) {
+        onProgress(received / contentLength)
+      }
+    }
+  }
+
+  const fullBuffer = new Uint8Array(received)
+  let offset = 0
+  for (const chunk of chunks) {
+    fullBuffer.set(chunk, offset)
+    offset += chunk.length
+  }
+
+  const decryptedBytes = await decryptFile(fullBuffer, password)
+
+  // Create a blob and trigger a download
+  const blob = new Blob([decryptedBytes])
+  const downloadUrl = URL.createObjectURL(blob)
+  const a = document.createElement('a')
+  a.href = downloadUrl
+  a.download = fileName
+  document.body.appendChild(a)
+  a.click()
+  a.remove()
+  URL.revokeObjectURL(downloadUrl)
+}
+
+export async function decryptFile(fileBuffer: Uint8Array, password: string): Promise<Uint8Array> {
+  const salt = fileBuffer.slice(0, 16)
+  const nonce = fileBuffer.slice(16, 28)
+  const tag = fileBuffer.slice(28, 44)
+  const ciphertext = fileBuffer.slice(44)
+
+  const enc = new TextEncoder()
+  const keyMaterial = await crypto.subtle.importKey(
+    'raw',
+    enc.encode(password),
+    { name: 'PBKDF2' },
+    false,
+    ['deriveKey'],
+  )
+  const key = await crypto.subtle.deriveKey(
+    { name: 'PBKDF2', salt, iterations: 100000, hash: 'SHA-256' },
+    keyMaterial,
+    { name: 'AES-GCM', length: 256 },
+    false,
+    ['decrypt'],
+  )
+
+  const fullCiphertext = new Uint8Array(ciphertext.length + tag.length)
+  fullCiphertext.set(ciphertext)
+  fullCiphertext.set(tag, ciphertext.length)
+
+  let decrypted: ArrayBuffer
+  try {
+    decrypted = await crypto.subtle.decrypt(
+      { name: 'AES-GCM', iv: nonce, tagLength: 128 },
+      key,
+      fullCiphertext,
+    )
+  } catch {
+    throw new Error('Incorrect password or corrupted file.')
+  }
+
+  const magic = new TextEncoder().encode('DYSON1')
+  const decryptedBytes = new Uint8Array(decrypted)
+  for (let i = 0; i < magic.length; i++) {
+    if (decryptedBytes[i] !== magic[i]) {
+      throw new Error('Incorrect password or corrupted file.')
+    }
+  }
+
+  return decryptedBytes.slice(magic.length)
+}