# Dispatch & SDK patch

Rewrites client URLs to a chosen HTTP or HTTPS server. The server is a
host or IP with an optional port, without scheme or path.

## URL rules (`dispatch/mod.rs`)

- `dispatch` replaces the `"DispatchUrls": [...]` list with
  `"<origin>/query_dispatch"` entries inside its original byte range,
  space-padding the rest.
- `sdk` rewrites the URLs of the production `bh3_*` records in
  `server_pc` (`env` `0` for `bh3_cn`, else `2`), padding each record to
  its original length.
- `android_urls` rewrites `http(s)`/`ws(s)` URLs and bare hosts on the
  official domains (`bh3.com`, `honkaiimpact3.com`, `mihoyo.com`,
  `hoyoverse.com`, plus one known IP). Shorter replacements keep the
  original length with an `x…@` userinfo prefix; `ws`/`wss` follow the
  chosen scheme.

If a replacement is longer than the original, `dispatch_grow`, `sdk_grow`
or `android_urls_grow` writes it at full length and the asset is
enlarged: `unity::replace_script` rewrites the serialized object table and
header size, and `Bundle::replace_node` re-chunks a UnityFS node and
fixes its directory. The tool then prints a warning that assets were
enlarged.

## Windows (`dispatch/windows.rs`)

Writes three files together and rolls back on failure:

| File | Content patched |
| --- | --- |
| `BH3_Data/sharedassets0.assets` | `ChannelConfig` dispatch URLs; also identifies the region |
| `BH3_Data/resources.assets` | `server_pc` SDK URLs |
| `BH3_Data/StreamingAssets/MiHoYoSDKRes/PC/mihoyo_sdk_res` | the `server_pc` copy inside the SDK bundle |

Both `server_pc` copies must be byte-equal before patching.

## Android (`dispatch/android.rs`)

Patches serialized files, UnityFS bundle nodes and plain text among the
candidate `assets/` entries (`assets/bin/data/*` and known text
extensions, except `package_config.json`, `share_config.json`, `.wmv`
and `.bak`). `.splitN` parts are joined for patching and re-split at the
original chunk size; enlarging can add parts. DEX, native libraries and
`.wmv` are copied unchanged, except for the CN passport URL below. At
least one `ChannelConfig` and one SDK/resource URL are required, otherwise
no APK is written. The result is repacked and signed by `android::sign`.

## CN passport URL (`dispatch/cn_android.rs`)

The CN passport login URL is a plaintext string in the DEX that declares
`…account.sdk.utils.RSAUtils`; only that DEX is edited. The server must
use **HTTP** — HTTPS is rejected.

The patch inserts the origin as a new string at its sorted position in
`string_ids` (`format::dex::insert_string`) and repoints the
`const-string` that loaded the official login URL
(`https://passport-api.mihoyo.com`) to it, so login goes to the server.
Any origin is accepted, not only ones that sort next to a reusable slot.

Insertion shifts every string index at or after the new one, so
`insert_string` renumbers all references — the fixed-width id tables,
`const-string`/`const-string/jumbo` operands, and the ULEB128 string
indices in debug info and annotations — and relocates every file offset
(itself and the string data grow 4-aligned). A DEX with more than 65536
strings can hold a 16-bit `const-string` whose operand would overflow
when renumbered; `format::dex::promote` rewrites those to
`const-string/jumbo` first, rebuilding the affected method (branch and
switch targets fixed, the code item re-padded to 4-byte alignment). If
the origin is already present (for example the stock `http://127.0.0.1`
when the server runs on the device), the login is repointed to the
existing id with no insertion. Checksums are recomputed.