nettle/
helper.rs

1use crate::{Error, Result};
2use nettle_sys::{
3    __gmpz_clear, __mpz_struct, nettle_mpz_get_str_256,
4    nettle_mpz_init_set_str_256_u, nettle_mpz_sizeinbase_256_u,
5};
6use std::mem::zeroed;
7
8pub fn convert_gmpz_to_buffer(mut mpz: __mpz_struct) -> Box<[u8]> {
9    unsafe {
10        let mut ret = vec![0u8; nettle_mpz_sizeinbase_256_u(&mut mpz)];
11
12        nettle_mpz_get_str_256(ret.len(), ret.as_mut_ptr(), &mut mpz);
13
14        while ret.len() > 1 && ret[0] == 0 {
15            ret.remove(0);
16        }
17        ret.into()
18    }
19}
20
21/// Convert the buffer to an mpz number.
22///
23/// This inits the mpz number. Take care not to init twice!
24pub fn convert_buffer_to_gmpz(buf: &[u8]) -> __mpz_struct {
25    unsafe {
26        let mut ret = zeroed();
27
28        nettle_mpz_init_set_str_256_u(&mut ret, buf.len(), buf.as_ptr());
29        ret
30    }
31}
32
33pub fn write_gmpz_into_slice(
34    mut mpz: __mpz_struct,
35    slice: &mut [u8],
36    arg: &'static str,
37) -> Result<()> {
38    unsafe {
39        if nettle_mpz_sizeinbase_256_u(&mut mpz as *mut _) > slice.len() {
40            __gmpz_clear(&mut mpz);
41
42            Err(Error::InvalidArgument { argument_name: arg })
43        } else {
44            nettle_mpz_get_str_256(slice.len(), slice.as_mut_ptr(), &mut mpz);
45            __gmpz_clear(&mut mpz);
46
47            Ok(())
48        }
49    }
50}
nettle/helper.rs

nettle/
helper.rs
