/rust/registry/src/index.crates.io-1949cf8c6b5b557f/aws-lc-rs-1.14.1/src/constant_time.rs

Source
// Copyright 2015-2022 Brian Smith.
// SPDX-License-Identifier: ISC
// Modifications copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0 OR ISC

//! Constant-time operations.

use crate::aws_lc::CRYPTO_memcmp;
use crate::error;

/// Returns `Ok(())` if `a == b` and `Err(error::Unspecified)` otherwise.
///
/// The comparison of `a` and `b` is done in constant time with respect to the
/// contents of each, but NOT in constant time with respect to the lengths of
/// `a` and `b`.
///
/// # Errors
/// `error::Unspecified` when `a` and `b` differ.
#[inline]
pub fn verify_slices_are_equal(a: &[u8], b: &[u8]) -> Result<(), error::Unspecified> {
    if a.len() != b.len() {
        return Err(error::Unspecified);
    }
    let result = unsafe { CRYPTO_memcmp(a.as_ptr().cast(), b.as_ptr().cast(), a.len()) };
    match result {
        0 => Ok(()),
        _ => Err(error::Unspecified),
    }
}

Coverage Report

Created: 2025-11-16 06:35

Line	Count	Source
1		// Copyright 2015-2022 Brian Smith.
2		// SPDX-License-Identifier: ISC
3		// Modifications copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
4		// SPDX-License-Identifier: Apache-2.0 OR ISC
5
6		//! Constant-time operations.
7
8		use crate::aws_lc::CRYPTO_memcmp;
9		use crate::error;
10
11		/// Returns `Ok(())` if `a == b` and `Err(error::Unspecified)` otherwise.
12		///
13		/// The comparison of `a` and `b` is done in constant time with respect to the
14		/// contents of each, but NOT in constant time with respect to the lengths of
15		/// `a` and `b`.
16		///
17		/// # Errors
18		/// `error::Unspecified` when `a` and `b` differ.
19		#[inline]
20	0	pub fn verify_slices_are_equal(a: &[u8], b: &[u8]) -> Result<(), error::Unspecified> {
21	0	if a.len() != b.len() {
22	0	return Err(error::Unspecified);
23	0	}
24	0	let result = unsafe { CRYPTO_memcmp(a.as_ptr().cast(), b.as_ptr().cast(), a.len()) };
25	0	match result {
26	0	0 => Ok(()),
27	0	_ => Err(error::Unspecified),
28		}
29	0	} Unexecuted instantiation: aws_lc_rs::constant_time::verify_slices_are_equal Unexecuted instantiation: aws_lc_rs::constant_time::verify_slices_are_equal