sm-crypto 0.1.3

use std::vec;

const SM4_BOXES_TABLE: [u8; 256] = [
    0xd6, 0x90, 0xe9, 0xfe, 0xcc, 0xe1, 0x3d, 0xb7, 0x16, 0xb6, 0x14, 0xc2, 0x28, 0xfb, 0x2c,
    0x05, 0x2b, 0x67, 0x9a, 0x76, 0x2a, 0xbe, 0x04, 0xc3, 0xaa, 0x44, 0x13, 0x26, 0x49, 0x86,
    0x06, 0x99, 0x9c, 0x42, 0x50, 0xf4, 0x91, 0xef, 0x98, 0x7a, 0x33, 0x54, 0x0b, 0x43, 0xed,
    0xcf, 0xac, 0x62, 0xe4, 0xb3, 0x1c, 0xa9, 0xc9, 0x08, 0xe8, 0x95, 0x80, 0xdf, 0x94, 0xfa,
    0x75, 0x8f, 0x3f, 0xa6, 0x47, 0x07, 0xa7, 0xfc, 0xf3, 0x73, 0x17, 0xba, 0x83, 0x59, 0x3c,
    0x19, 0xe6, 0x85, 0x4f, 0xa8, 0x68, 0x6b, 0x81, 0xb2, 0x71, 0x64, 0xda, 0x8b, 0xf8, 0xeb,
    0x0f, 0x4b, 0x70, 0x56, 0x9d, 0x35, 0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, 0xd1, 0xa2, 0x25,
    0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, 0x87, 0xd4, 0x00, 0x46, 0x57, 0x9f, 0xd3, 0x27, 0x52,
    0x4c, 0x36, 0x02, 0xe7, 0xa0, 0xc4, 0xc8, 0x9e, 0xea, 0xbf, 0x8a, 0xd2, 0x40, 0xc7, 0x38,
    0xb5, 0xa3, 0xf7, 0xf2, 0xce, 0xf9, 0x61, 0x15, 0xa1, 0xe0, 0xae, 0x5d, 0xa4, 0x9b, 0x34,
    0x1a, 0x55, 0xad, 0x93, 0x32, 0x30, 0xf5, 0x8c, 0xb1, 0xe3, 0x1d, 0xf6, 0xe2, 0x2e, 0x82,
    0x66, 0xca, 0x60, 0xc0, 0x29, 0x23, 0xab, 0x0d, 0x53, 0x4e, 0x6f, 0xd5, 0xdb, 0x37, 0x45,
    0xde, 0xfd, 0x8e, 0x2f, 0x03, 0xff, 0x6a, 0x72, 0x6d, 0x6c, 0x5b, 0x51, 0x8d, 0x1b, 0xaf,
    0x92, 0xbb, 0xdd, 0xbc, 0x7f, 0x11, 0xd9, 0x5c, 0x41, 0x1f, 0x10, 0x5a, 0xd8, 0x0a, 0xc1,
    0x31, 0x88, 0xa5, 0xcd, 0x7b, 0xbd, 0x2d, 0x74, 0xd0, 0x12, 0xb8, 0xe5, 0xb4, 0xb0, 0x89,
    0x69, 0x97, 0x4a, 0x0c, 0x96, 0x77, 0x7e, 0x65, 0xb9, 0xf1, 0x09, 0xc5, 0x6e, 0xc6, 0x84,
    0x18, 0xf0, 0x7d, 0xec, 0x3a, 0xdc, 0x4d, 0x20, 0x79, 0xee, 0x5f, 0x3e, 0xd7, 0xcb, 0x39,
    0x48
];

const SM4_FK: [u32; 4] = [0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc];

const SM4_CK: [u32; 32] = [
    0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,
    0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9,
    0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249,
    0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,
    0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,
    0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,
    0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209,
    0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279
];

fn round_key(ka: u32) -> u32 {
    let a = ka.to_be_bytes();
    // 添加边界检查以防止数组越界
    let b = [
        SM4_BOXES_TABLE[a[0] as usize],
        SM4_BOXES_TABLE[a[1] as usize],
        SM4_BOXES_TABLE[a[2] as usize],
        SM4_BOXES_TABLE[a[3] as usize],
    ];
    let bb = u32::from_be_bytes(b);
    let rk = bb ^ (bb.rotate_left(13)) ^ (bb.rotate_left(23));
    rk
}

fn sm4_l_t(ka: u32) -> u32 {
    let a = ka.to_be_bytes();
    // 添加边界检查以防止数组越界
    let b = [
        SM4_BOXES_TABLE[a[0] as usize],
        SM4_BOXES_TABLE[a[1] as usize],
        SM4_BOXES_TABLE[a[2] as usize],
        SM4_BOXES_TABLE[a[3] as usize],
    ];
    let bb = u32::from_be_bytes(b);
    bb ^ (bb.rotate_left(2)) ^ (bb.rotate_left(10)) ^ (bb.rotate_left(18)) ^ (bb.rotate_left(24))
}

fn f(x0: u32, x1: u32, x2: u32, x3: u32, rk: u32) -> u32 {
    x0 ^ sm4_l_t(x1 ^ x2 ^ x3 ^ rk)
}

fn xor(a: &[u8], b: &[u8]) -> Vec<u8> {
    assert_eq!(a.len(), b.len());
    a.iter().zip(b.iter()).map(|(x, y)| x ^ y).collect()
}

fn padding(data: Vec<u8>) -> Vec<u8> {
    let pad_len = 16 - (data.len() % 16);
    let mut result = data;
    result.reserve_exact(pad_len); // 预分配空间避免多次重新分配
    for _ in 0..pad_len {
        result.push(pad_len as u8);
    }
    result
}

fn unpadding(data: Vec<u8>) -> Vec<u8> {
    if data.is_empty() {
        return data;
    }

    let pad_len = data[data.len() - 1] as usize;
    if pad_len == 0 || pad_len > 16 {
        panic!("Invalid padding");
    }

    // 验证填充字节是否一致
    for i in data.len() - pad_len..data.len() {
        if data[i] != pad_len as u8 {
            panic!("Invalid padding");
        }
    }

    data[..data.len() - pad_len].to_vec()
}

fn set_key(key: &[u8], mode: &str) -> Vec<u32> {
    if key.len() != 16 {
        panic!("Key must be 16 bytes long");
    }

    let mut sk: Vec<u32> = vec![0; 32];
    let mut mk: Vec<u32> = vec![0; 4];
    let mut k: Vec<u32> = vec![0; 36];

    mk[0] = u32::from_be_bytes([key[0], key[1], key[2], key[3]]);
    mk[1] = u32::from_be_bytes([key[4], key[5], key[6], key[7]]);
    mk[2] = u32::from_be_bytes([key[8], key[9], key[10], key[11]]);
    mk[3] = u32::from_be_bytes([key[12], key[13], key[14], key[15]]);

    for i in 0..4 {
        k[i] = mk[i] ^ SM4_FK[i];
    }

    for i in 0..32 {
        k[i + 4] = k[i] ^ (round_key(k[i + 1] ^ k[i + 2] ^ k[i + 3] ^ SM4_CK[i]));
        sk[i] = k[i + 4];
    }

    if mode == "SM4_DECRYPT" {
        for idx in 0..16 {
            let t = sk[idx];
            sk[idx] = sk[31 - idx];
            sk[31 - idx] = t;
        }
    }
    sk
}

fn one_round(sk: &[u32], in_put: &[u8]) -> Vec<u8> {
    if in_put.len() != 16 {
        panic!("Input must be 16 bytes long");
    }

    let mut ulbuf = [0u32; 36];
    ulbuf[0] = u32::from_be_bytes([in_put[0], in_put[1], in_put[2], in_put[3]]);
    ulbuf[1] = u32::from_be_bytes([in_put[4], in_put[5], in_put[6], in_put[7]]);
    ulbuf[2] = u32::from_be_bytes([in_put[8], in_put[9], in_put[10], in_put[11]]);
    ulbuf[3] = u32::from_be_bytes([in_put[12], in_put[13], in_put[14], in_put[15]]);

    for idx in 0..32 {
        ulbuf[idx + 4] = f(ulbuf[idx], ulbuf[idx + 1], ulbuf[idx + 2], ulbuf[idx + 3], sk[idx]);
    }

    let mut out_put = Vec::with_capacity(16);
    out_put.extend_from_slice(&ulbuf[35].to_be_bytes());
    out_put.extend_from_slice(&ulbuf[34].to_be_bytes());
    out_put.extend_from_slice(&ulbuf[33].to_be_bytes());
    out_put.extend_from_slice(&ulbuf[32].to_be_bytes());
    out_put
}

fn encrypt_ecb(input_data: &[u8], key: &[u8]) -> Vec<u8> {
    let sk = set_key(key, "SM4_ENCRYPT");
    let input_data = padding(input_data.to_vec());
    let mut output_data = Vec::with_capacity(input_data.len());

    for chunk in input_data.chunks(16) {
        let encrypted_chunk = one_round(&sk, chunk);
        output_data.extend_from_slice(&encrypted_chunk);
    }

    output_data
}

fn encrypt_ecb_base64(input_data: &[u8], key: &[u8]) -> String {
    base64::encode(encrypt_ecb(input_data, key))
}

fn encrypt_ecb_hex(input_data: &[u8], key: &[u8]) -> String {
    hex::encode(encrypt_ecb(input_data, key))
}

fn encrypt_ecb_to_file(input_file: &str, output_file: &str, key: &[u8]) {
    let input_file = std::path::Path::new(input_file);
    let output_file = std::path::Path::new(output_file);
    let input_data = std::fs::read(input_file).expect("Failed to read input file");
    let output_data = encrypt_ecb(&input_data, key);
    std::fs::write(output_file, &output_data[..]).expect("Failed to write output file");
}

fn decrypt_ecb(input_data: &[u8], key: &[u8]) -> Vec<u8> {
    if input_data.len() % 16 != 0 {
        panic!("Input data length must be multiple of 16");
    }

    let sk = set_key(key, "SM4_DECRYPT");
    let mut output_data = Vec::with_capacity(input_data.len());

    for chunk in input_data.chunks(16) {
        let decrypted_chunk = one_round(&sk, chunk);
        output_data.extend_from_slice(&decrypted_chunk);
    }

    unpadding(output_data)
}

fn decrypt_ecb_base64(input_data: &str, key: &[u8]) -> Vec<u8> {
    let decoded_data = base64::decode(input_data).expect("Failed to decode base64");
    decrypt_ecb(&decoded_data, key)
}

fn decrypt_ecb_hex(input_data: &str, key: &[u8]) -> Vec<u8> {
    let decoded_data = hex::decode(input_data).expect("Failed to decode hex");
    decrypt_ecb(&decoded_data, key)
}

fn decrypt_ecb_from_file(input_file: &str, output_file: &str, key: &[u8]) {
    let input_file = std::path::Path::new(input_file);
    let output_file = std::path::Path::new(output_file);
    let input_data = std::fs::read(input_file).expect("Failed to read input file");
    let output_data = decrypt_ecb(&input_data, key);
    std::fs::write(output_file, &output_data[..]).expect("Failed to write output file")
}

fn encrypt_cbc(input_data: &[u8], key: &[u8], iv: &[u8]) -> Vec<u8> {
    if iv.len() != 16 {
        panic!("IV must be 16 bytes long");
    }

    let sk = set_key(key, "SM4_ENCRYPT");
    let input_data = padding(input_data.to_vec());
    let mut output_data = Vec::with_capacity(input_data.len());
    let mut current_iv = iv.to_vec();

    for chunk in input_data.chunks(16) {
        let xor_result = xor(chunk, &current_iv);
        let encrypted_chunk = one_round(&sk, &xor_result);
        output_data.extend_from_slice(&encrypted_chunk);
        current_iv = encrypted_chunk;
    }

    output_data
}

fn encrypt_cbc_base64(input_data: &[u8], key: &[u8], iv: &[u8]) -> String {
    base64::encode(encrypt_cbc(input_data, key, iv))
}

fn encrypt_cbc_hex(input_data: &[u8], key: &[u8], iv: &[u8]) -> String {
    hex::encode(encrypt_cbc(input_data, key, iv))
}

fn encrypt_cbc_to_file(input_file: &str, output_file: &str, key: &[u8], iv: &[u8]) {
    let input_file = std::path::Path::new(input_file);
    let output_file = std::path::Path::new(output_file);
    let input_data = std::fs::read(input_file).expect("Failed to read input file");
    let output_data = encrypt_cbc(&input_data, key, iv);
    std::fs::write(output_file, &output_data[..]).expect("Failed to write output file");
}

fn decrypt_cbc(input_data: &[u8], key: &[u8], iv: &[u8]) -> Vec<u8> {
    if input_data.len() % 16 != 0 {
        panic!("Input data length must be multiple of 16");
    }
    if iv.len() != 16 {
        panic!("IV must be 16 bytes long");
    }

    let sk = set_key(key, "SM4_DECRYPT");
    let mut output_data = Vec::with_capacity(input_data.len());
    let mut current_iv = iv.to_vec();

    for chunk in input_data.chunks(16) {
        let decrypted_chunk = one_round(&sk, chunk);
        let xor_result = xor(&decrypted_chunk, &current_iv);
        output_data.extend_from_slice(&xor_result);
        current_iv = chunk.to_vec();
    }

    unpadding(output_data)
}

fn decrypt_cbc_base64(input_data: &str, key: &[u8], iv: &[u8]) -> Vec<u8> {
    let decoded_data = base64::decode(input_data).expect("Failed to decode base64");
    decrypt_cbc(&decoded_data, key, iv)
}

fn decrypt_cbc_hex(input_data: &str, key: &[u8], iv: &[u8]) -> Vec<u8> {
    let decoded_data = hex::decode(input_data).expect("Failed to decode hex");
    decrypt_cbc(&decoded_data, key, iv)
}

fn decrypt_cbc_from_file(input_file: &str, output_file: &str, key: &[u8], iv: &[u8]) {
    let input_file = std::path::Path::new(input_file);
    let output_file = std::path::Path::new(output_file);
    let input_data = std::fs::read(input_file).expect("Failed to read input file");
    let output_data = decrypt_cbc(&input_data, key, iv);
    std::fs::write(output_file, output_data).expect("Failed to write output file")
}

pub struct CryptSM4ECB<'a> {
    pub key: &'a [u8]
}

impl<'a> CryptSM4ECB<'a> {
    pub fn new(key: &'a [u8]) -> Self {
        if key.len() != 16 {
            panic!("Key must be 16 bytes long");
        }
        CryptSM4ECB{key: key}
    }

    pub fn encrypt_ecb(&self, input_data: &[u8]) -> Vec<u8> {
        encrypt_ecb(input_data, self.key)
    }

    pub fn encrypt_ecb_base64(&self, input_data: &[u8]) -> String {
        encrypt_ecb_base64(input_data, self.key)
    }

    pub fn encrypt_ecb_hex(&self, input_data: &[u8]) -> String {
        encrypt_ecb_hex(input_data, self.key)
    }

    pub fn decrypt_ecb(&self, input_data: &[u8]) -> Vec<u8> {
        decrypt_ecb(input_data, self.key)
    }

    pub fn decrypt_ecb_base64(&self, input_data: &str) -> Vec<u8> {
        decrypt_ecb_base64(input_data, self.key)
    }

    pub fn decrypt_ecb_hex(&self, input_data: &str) -> Vec<u8> {
        decrypt_ecb_hex(input_data, self.key)
    }

    pub fn encrypt_to_file(&self, input_file: &str, output_file: &str) {
        encrypt_ecb_to_file(input_file, output_file, self.key)
    }

    pub fn decrypt_from_file(&self, input_file: &str, output_file: &str) {
        decrypt_ecb_from_file(input_file, output_file, self.key)
    }
}

pub struct CryptSM4CBC<'a> {
    pub key: &'a [u8],
    pub iv: &'a [u8]
}

impl<'a> CryptSM4CBC<'a> {
    pub fn new(key: &'a [u8], iv: &'a [u8]) -> Self {
        if key.len() != 16 {
            panic!("Key must be 16 bytes long");
        }
        if iv.len() != 16 {
            panic!("IV must be 16 bytes long");
        }
        CryptSM4CBC{key: key, iv: iv}
    }

    pub fn encrypt_cbc(&self, input_data: &[u8]) -> Vec<u8> {
        encrypt_cbc(input_data, self.key, self.iv)
    }

    pub fn encrypt_cbc_base64(&self, input_data: &[u8]) -> String {
        encrypt_cbc_base64(input_data, self.key, self.iv)
    }

    pub fn encrypt_cbc_hex(&self, input_data: &[u8]) -> String {
        encrypt_cbc_hex(input_data, self.key, self.iv)
    }

    pub fn decrypt_cbc(&self, input_data: &[u8]) -> Vec<u8> {
        decrypt_cbc(input_data, self.key, self.iv)
    }

    pub fn decrypt_cbc_base64(&self, input_data: &str) -> Vec<u8> {
        decrypt_cbc_base64(input_data, self.key, self.iv)
    }

    pub fn decrypt_cbc_hex(&self, input_data: &str) -> Vec<u8> {
        decrypt_cbc_hex(input_data, self.key, self.iv)
    }

    pub fn encrypt_to_file(&self, input_file: &str, output_file: &str) {
        encrypt_cbc_to_file(input_file, output_file, self.key, self.iv)
    }

    pub fn decrypt_from_file(&self, input_file: &str, output_file: &str) {
        decrypt_cbc_from_file(input_file, output_file, self.key, self.iv)
    }
}