feat: first version

README.md

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+# tc_tea
+
+Rusty implementation of _Tencent modified TEA_ (tc_tea).
+
+Test data generated using its C++ implementation: [tc_tea.cpp][tc_tea_cpp] (BSD-3-Clause).
+
+Code implemented according to the spec described in
+[iweizime/StepChanger:腾讯 TEA 加密算法][tc_tea_spec].
+
+## Features
+
+* `secure_random` (default: `on`): Enable secure RNG when generating padding bytes for tc_tea.
+
+## Install
+
+Add the following to `[dependencies]` section in your `Cargo.toml` file:
+
+```toml
+tc_tea = "0.1.0"
+```
+
+## Failures
+
+* Key size needs to be `>= 16` bytes.
+  * `None` will be returned in this case.
+  * Only first 16 bytes are used.
+* Encrypted size are always multiple of 8.
+  * `None` will be returned in this case.
+
+## Usage
+
+```rust
+use tc_tea;
+
+fn hello_tc_tea() {
+    let key = "12345678ABCDEFGH";
+    let encrypted = tc_tea::encrypt(&"hello", &key).unwrap();
+    let decrypted = tc_tea::decrypt(&encrypted, &key).unwrap();
+    assert_eq!("hello", std::str::from_utf8(&decrypted).unwrap());
+}
+```
+
+## License
+
+Dual licensed under MIT OR Apache-2.0 license.
+
+`SPDX-License-Identifier: MIT OR Apache-2.0`
+
+[tc_tea_cpp]: https://github.com/TarsCloud/TarsCpp/blob/a6d5ed8/util/src/tc_tea.cpp
+[tc_tea_spec]: https://github.com/iweizime/StepChanger/wiki/%E8%85%BE%E8%AE%AFTEA%E5%8A%A0%E5%AF%86%E7%AE%97%E6%B3%95