ssh_cli/
masking.rs

1// SPDX-License-Identifier: MIT OR Apache-2.0
2// G-SECDEV-05: pure module — no `unsafe` permitted (crate root allows only OS FFI / test env).
3#![forbid(unsafe_code)]
4//! Masking of sensitive values (passwords, tokens) — agent-safe.
5//!
6//! Rule (GAP-SSH-SEC-002): **always** returns `"***"`, without exposing prefix/suffix.
7//!
8//! Performance: returns `&'static str` (zero heap). Callers that need owned
9//! values can `.to_string()` / `.into()` at the edge — never allocate in the
10//! mask path itself (Rules Rust: treat every allocation as measurable cost).
11
12/// Fixed placeholder for any sensitive value.
13pub const FIXED_MASK: &str = "***";
14
15/// Masks a sensitive value without leaking useful characters.
16///
17/// Always returns the static placeholder [`FIXED_MASK`]. No heap allocation.
18///
19/// # Examples
20///
21/// ```
22/// use ssh_cli::masking::mask;
23///
24/// assert_eq!(mask("curto"), "***");
25/// assert_eq!(mask("password-secreta-muito-longa-aqui-123456"), "***");
26/// assert_eq!(mask("a"), ssh_cli::masking::FIXED_MASK);
27/// ```
28#[must_use]
29#[inline]
30pub fn mask(_valor: &str) -> &'static str {
31    FIXED_MASK
32}
33
34#[cfg(test)]
35mod tests {
36    use super::*;
37
38    #[test]
39    fn empty_value_returns_triple_asterisk() {
40        assert_eq!(mask(""), "***");
41    }
42
43    #[test]
44    fn short_value_returns_triple_asterisk() {
45        assert_eq!(mask("abc"), "***");
46    }
47
48    #[test]
49    fn long_value_never_exposes_prefix_or_suffix() {
50        let password = "senha-secreta-muito-longa-aqui-123456";
51        assert_eq!(mask(password), "***");
52        assert!(!mask(password).contains("senha"));
53        assert!(!mask(password).contains("1234"));
54    }
55
56    #[test]
57    fn unicode_value_does_not_crash() {
58        let emojis = "🔒🔑🛡🔐✨🎉💎⚡🌟🔥🎨🚀🌈🍀🎯🎪🎭🎬🎮🎲";
59        assert_eq!(mask(emojis), "***");
60    }
61
62    #[test]
63    fn mask_returns_static_placeholder() {
64        // API contract: &'static str equal to FIXED_MASK (no owned String).
65        let m: &'static str = mask("secret");
66        assert_eq!(m, FIXED_MASK);
67        assert_eq!(m, "***");
68    }
69}
ssh_cli/masking.rs

ssh_cli/
masking.rs
