sm4-gcm

Encrypt & Decrypt test code: ```rust fn main() { let key = Sm4Key([0u8; 16]); let nonce = [0u8; 12]; let plaintext = b"Hello World!";

let ciphertext = sm4_gcm::sm4_gcm_encrypt(&key, &nonce, plaintext);
println!("Encrypted: {}", hex::encode(&ciphertext));
let decrypted = sm4_gcm::sm4_gcm_decrypt(&key, &nonce, &ciphertext).unwrap();
println!("Decrypted: {}", String::from_utf8_lossy(&decrypted));

} ```

Generate test vector BC test code: java public static void encryptGcmNoPadding(String key, String data, String nonce, String associatedData) throws Exception { Cipher cipher = Cipher.getInstance("SM4/GCM/NoPadding", BouncyCastleProvider.PROVIDER_NAME); Key sm4Key = new SecretKeySpec(Bytes.fromHex(key).bytes(), "SM4"); byte[] iv = Bytes.fromHex(nonce).bytes(); GCMParameterSpec s = new GCMParameterSpec(128, iv); cipher.init(Cipher.ENCRYPT_MODE, sm4Key, s); if (associatedData != null && associatedData.length() > 0) { cipher.updateAAD(Bytes.fromHex(associatedData).bytes()); } byte[] aa = cipher.doFinal(data.getBytes(StandardCharsets.UTF_8)); System.out.println(Bytes.from(aa).asHex()); }

Benchmark @MacBook Pro (Retina, 15-inch, Late 2013/2 GHz Quad-Core Intel Core i7) text $ cargo run --release --example bench SM4/GCM encrypt : 65.69 M/s