apple-cryptokit-rs 0.1.2

// SHA-256 哈希算法实现

use super::HashFunction;
use std::ffi::c_void;

// SHA256 Swift FFI 声明
extern "C" {
    #[link_name = "sha256_hash"]
    fn swift_sha256_hash(data: *const u8, length: i32, out_hash: *mut u8);

    #[link_name = "sha256_init"]
    fn swift_sha256_init() -> *mut c_void;

    #[link_name = "sha256_update"]
    fn swift_sha256_update(ptr: *mut c_void, data: *const u8, len: i32);

    #[link_name = "sha256_finalize"]
    fn swift_sha256_finalize(ptr: *mut c_void, out: *mut u8);

    #[link_name = "sha256_free"]
    fn swift_sha256_free(ptr: *mut c_void);
}

/// SHA256 一次性哈希计算
pub fn sha256_hash(data: &[u8]) -> [u8; 32] {
    unsafe {
        let mut output_hash = [0u8; 32];
        swift_sha256_hash(data.as_ptr(), data.len() as i32, output_hash.as_mut_ptr());
        output_hash
    }
}

/// SHA256 流式哈希状态
pub struct Sha256 {
    ptr: *mut c_void,
}

impl Sha256 {
    /// 创建新的SHA256哈希状态
    pub fn new() -> Self {
        let ptr = unsafe { swift_sha256_init() };
        Self { ptr }
    }

    /// 更新哈希状态
    pub fn update(&mut self, data: &[u8]) {
        unsafe {
            swift_sha256_update(self.ptr, data.as_ptr(), data.len() as i32);
        }
    }

    /// 完成哈希计算并返回结果
    pub fn finalize(self) -> [u8; 32] {
        self.snapshot()
    }

    pub fn snapshot(&self) -> [u8; 32] {
        let mut hash = [0u8; 32];
        unsafe {
            swift_sha256_finalize(self.ptr, hash.as_mut_ptr());
        }
        hash
    }
}

impl Default for Sha256 {
    fn default() -> Self {
        Self::new()
    }
}

impl Drop for Sha256 {
    fn drop(&mut self) {
        unsafe {
            swift_sha256_free(self.ptr);
        }
    }
}

/// SHA256 哈希算法实现
pub struct SHA256;

impl HashFunction for SHA256 {
    type Output = [u8; 32];

    fn hash(data: &[u8]) -> Self::Output {
        sha256_hash(data)
    }
}

// Re-export
pub use SHA256 as Sha256Algorithm;