lib3h_sodium 0.0.10

lib3h libsodium wrapper providing memory secure api access
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92

//! This module provides access to libsodium

use super::{check_init, secbuf::SecBuf};
use lib3h_crypto_api::CryptoError;

pub const CONTEXTBYTES: usize = rust_sodium_sys::crypto_kdf_CONTEXTBYTES as usize;
pub const MINBYTES: usize = rust_sodium_sys::crypto_kdf_BYTES_MIN as usize;
pub const MAXBYTES: usize = rust_sodium_sys::crypto_kdf_BYTES_MAX as usize;

/// Derive a subkey from a parent key
/// ****
/// @param {SecBuf} out - Empty Buffer to be used as output
///
/// @param {number} index - subkey index
///
/// @param {Buffer} context - eight bytes context
///
/// @param {SecBuf} parent - the parent key to derive from

pub fn derive(
    out: &mut SecBuf,
    index: u64,
    context: &mut SecBuf,
    parent: &mut SecBuf,
) -> Result<(), CryptoError> {
    check_init();
    {
        let out = out.read_lock();
        let o = out.len();
        let context = context.read_lock();
        let c = context.len();
        if o < MINBYTES || o > MAXBYTES {
            return Err(CryptoError::OutputLength(format!(
                "Invalid 'out' Buffer length:{}",
                o
            )));
        } else if c != CONTEXTBYTES {
            return Err(CryptoError::OutputLength(format!(
                "context must be a Buffer of length: {}.",
                CONTEXTBYTES
            )));
        }
    }
    let mut out = out.write_lock();
    let parent = parent.read_lock();
    let context = context.read_lock();
    unsafe {
        rust_sodium_sys::crypto_kdf_derive_from_key(
            raw_ptr_char!(out),
            out.len(),
            index,
            raw_ptr_ichar_immut!(context),
            raw_ptr_char_immut!(parent),
        );
    }
    Ok(())
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn it_should_derive_consistantly() {
        let mut context = SecBuf::with_secure(CONTEXTBYTES);
        let mut parent = SecBuf::with_secure(32);
        context.randomize();
        parent.randomize();
        let mut out1 = SecBuf::with_secure(32);
        let mut out2 = SecBuf::with_secure(32);
        {
            derive(&mut out1, 3, &mut context, &mut parent).unwrap();
        }
        {
            derive(&mut out2, 3, &mut context, &mut parent).unwrap();
        }
        let out1 = out1.read_lock();
        let out2 = out2.read_lock();
        assert_eq!(format!("{:?}", *out1), format!("{:?}", *out2));
    }
    #[test]
    fn it_should_return_error_on_bad_output_buffer() {
        let mut context = SecBuf::with_secure(8);
        let mut parent = SecBuf::with_secure(32);
        context.randomize();
        parent.randomize();
        let mut out = SecBuf::with_insecure(2);
        {
            derive(&mut out, 3, &mut context, &mut parent).expect_err("should have failed");
        }
    }
}