feat: implement AuthLite

sdgb-api/Cargo.toml

@@ -9,8 +9,10 @@ license = "GPL-3.0"
 snafu = { workspace = true }
 serde_json = { workspace = true }
 
+# hashing
 digest = "0.10.7"
 hmac-sha256 = { version = "1.1.12", features = ["digest010", "traits010"] }
+md5 = "0.8.0"
 
 # other utils
 chrono = "0.4.41"
@@ -22,8 +24,8 @@ nyquest = { version = "0.2.0", features = ["async", "json"] }
 # (de)serialization
 serde = { version = "1.0.219", features = ["derive"] }
 
+# compression / encryption
 flate2 = "1.1.2"
 cbc = "0.1.2"
 aes = "0.8.4"
-md5 = "0.8.0"
-block-padding = "0.3.3"
+cipher = { version = "0.4.4", features = ["block-padding"] }

sdgb-api/src/auth_lite/mod.rs

@@ -0,0 +1,62 @@
+use cipher::{
+    BlockDecryptMut as _, BlockEncryptMut as _, BlockSizeUser as _, KeyIvInit as _,
+    block_padding::Pkcs7, generic_array::GenericArray,
+};
+use nyquest::{
+    AsyncClient,
+    r#async::{Body, Request},
+    header::USER_AGENT,
+};
+
+use crate::error::ApiError;
+
+const AES_KEY: &[u8; 16] = br#"/?jo+"L&\Cr9(=kG"#;
+const AES_IV: &[u8; 16] = b"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
+
+pub async fn delivery_raw(
+    client: &AsyncClient,
+    title_ver: impl AsRef<str>,
+) -> Result<Vec<u8>, ApiError> {
+    let title_ver = title_ver.as_ref();
+    let params = format!("title_id=SDGB&title_ver={title_ver}&client_id=A63E01C2805");
+    let enc_data = encrypt(params, AES_KEY, AES_IV)?;
+
+    let req = Request::post("http://at.sys-allnet.cn/net/delivery/instruction")
+        .with_body(Body::bytes(enc_data, "application/xxx-form-urlencoded"))
+        .with_header(USER_AGENT, "SDGB;Windows/Lite")
+        .with_header("Pragma", "DFI");
+
+    let mut resp = client.request(req).await?.bytes().await?;
+    let dec_len = decrypt(&mut resp, AES_KEY, AES_IV)?.len();
+    resp.truncate(dec_len);
+    Ok(resp)
+}
+
+type Aes128CbcEnc = cbc::Encryptor<aes::Aes128>;
+type Aes128CbcDec = cbc::Decryptor<aes::Aes128>;
+
+fn encrypt(data: impl AsRef<[u8]>, key: &[u8; 16], iv: &[u8; 16]) -> Result<Vec<u8>, ApiError> {
+    let key = GenericArray::from_slice(key);
+    let iv = GenericArray::from_slice(iv);
+    let encryptor = Aes128CbcEnc::new(key, iv);
+    let data = data.as_ref();
+    let bs = aes::Aes256::block_size();
+    let pad_len = bs - data.len() % bs;
+
+    let mut buf = vec![0; pad_len + data.len()];
+    buf[..data.len()].copy_from_slice(&data);
+    encryptor.encrypt_padded_mut::<Pkcs7>(&mut buf, data.len())?;
+    Ok(buf)
+}
+
+fn decrypt<'ct>(
+    data: &'ct mut impl AsMut<[u8]>,
+    key: &[u8; 16],
+    iv: &[u8; 16],
+) -> Result<&'ct [u8], ApiError> {
+    let key = GenericArray::from_slice(key);
+    let iv = GenericArray::from_slice(iv);
+    let decryptor = Aes128CbcDec::new(key, iv);
+    let result = decryptor.decrypt_padded_mut::<Pkcs7>(data.as_mut())?;
+    Ok(result)
+}

sdgb-api/src/lib.rs

@@ -1,2 +1,6 @@
-pub mod title;
 pub mod all_net;
+pub mod auth_lite;
+pub mod title;
+
+mod error;
+pub use error::ApiError;

sdgb-api/src/title/encryption/mod.rs

@@ -8,7 +8,8 @@ use digest::generic_array::GenericArray;
 use flate2::write::ZlibEncoder;
 use flate2::{Compression, read::ZlibDecoder};
 
-use crate::title::{MaiVersion, MaiVersionExt, Sdgb1_40, Sdgb1_50, error::ApiError};
+use crate::error::ApiError;
+use crate::title::{MaiVersion, MaiVersionExt, Sdgb1_40, Sdgb1_50};
 
 impl MaiVersionExt for Sdgb1_40 {
     fn decode(mut data: impl AsMut<[u8]>) -> Result<Vec<u8>, ApiError> {

sdgb-api/src/title/mod.rs

@@ -6,8 +6,8 @@ pub mod encryption;
 pub mod methods;
 pub mod model;
 
-mod error;
-pub use error::ApiError;
+use super::ApiError;
+
 use nyquest::{
     AsyncClient, Body,
     r#async::Request,