t_rust_less_lib/memguard/
zeroize_buffer.rs

1use std::io;
2use std::ops;
3use zeroize::Zeroize;
4
5pub struct ZeroizeBytesBuffer(Vec<u8>);
6
7impl ZeroizeBytesBuffer {
8  pub fn with_capacity(initial_capacity: usize) -> ZeroizeBytesBuffer {
9    ZeroizeBytesBuffer(Vec::with_capacity(initial_capacity))
10  }
11}
12
13impl ZeroizeBytesBuffer {
14  pub fn append(&mut self, byte: u8) {
15    if self.0.len() <= self.0.capacity() {
16      let next_size = 2 * (self.0.capacity() + 1);
17      let mut next_buffer = Vec::with_capacity(next_size);
18
19      next_buffer.extend_from_slice(&self.0);
20
21      self.0.zeroize();
22      self.0 = next_buffer;
23    }
24    self.0.push(byte)
25  }
26}
27
28impl Zeroize for ZeroizeBytesBuffer {
29  fn zeroize(&mut self) {
30    self.0.zeroize();
31  }
32}
33
34impl Drop for ZeroizeBytesBuffer {
35  fn drop(&mut self) {
36    self.0.zeroize()
37  }
38}
39
40impl ops::Deref for ZeroizeBytesBuffer {
41  type Target = [u8];
42
43  fn deref(&self) -> &Self::Target {
44    self.0.as_ref()
45  }
46}
47
48impl AsRef<[u8]> for ZeroizeBytesBuffer {
49  fn as_ref(&self) -> &[u8] {
50    self.0.as_ref()
51  }
52}
53
54impl io::Write for ZeroizeBytesBuffer {
55  fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
56    let avalable = self.0.capacity() - self.0.len();
57
58    if buf.len() < avalable {
59      // This should not require any reallocation
60      self.0.extend_from_slice(buf);
61    } else {
62      // To be on the save side with create copy with larger capacity and zero out the old
63      let next_size = 2 * (self.0.capacity() + buf.len());
64      let mut next_buffer = Vec::with_capacity(next_size);
65
66      next_buffer.extend_from_slice(&self.0);
67      next_buffer.extend_from_slice(buf);
68
69      self.0.zeroize();
70      self.0 = next_buffer;
71    }
72
73    Ok(buf.len())
74  }
75
76  fn flush(&mut self) -> io::Result<()> {
77    Ok(())
78  }
79}
t_rust_less_lib/memguard/zeroize_buffer.rs

t_rust_less_lib/memguard/
zeroize_buffer.rs
