From 04cadb4fe0341304741ef60a297366b553f0ce36 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 10 Oct 2025 17:10:47 -0700 Subject: lib/crypto: Add FIPS self-tests for SHA-1 and SHA-2 Add FIPS cryptographic algorithm self-tests for all SHA-1 and SHA-2 algorithms. Following the "Implementation Guidance for FIPS 140-3" document, to achieve this it's sufficient to just test a single test vector for each of HMAC-SHA1, HMAC-SHA256, and HMAC-SHA512. Just run these tests in the initcalls, following the example of e.g. crypto/kdf_sp800108.c. Note that this should meet the FIPS self-test requirement even in the built-in case, given that the initcalls run before userspace, storage, network, etc. are accessible. This does not fix a regression, seeing as lib/ has had SHA-1 support since 2005 and SHA-256 support since 2018. Neither ever had FIPS self-tests. Moreover, fips=1 support has always been an unfinished feature upstream. However, with lib/ now being used more widely, it's now seeing more scrutiny and people seem to want these now [1][2]. [1] https://lore.kernel.org/r/3226361.1758126043@warthog.procyon.org.uk/ [2] https://lore.kernel.org/r/f31dbb22-0add-481c-aee0-e337a7731f8e@oracle.com/ Reviewed-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20251011001047.51886-1-ebiggers@kernel.org Signed-off-by: Eric Biggers --- scripts/crypto/gen-fips-testvecs.py | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100755 scripts/crypto/gen-fips-testvecs.py (limited to 'scripts/crypto') diff --git a/scripts/crypto/gen-fips-testvecs.py b/scripts/crypto/gen-fips-testvecs.py new file mode 100755 index 000000000000..2956f88b764a --- /dev/null +++ b/scripts/crypto/gen-fips-testvecs.py @@ -0,0 +1,32 @@ +#!/usr/bin/env python3 +# SPDX-License-Identifier: GPL-2.0-or-later +# +# Script that generates lib/crypto/fips.h +# +# Copyright 2025 Google LLC + +import hmac + +fips_test_data = b"fips test data\0\0" +fips_test_key = b"fips test key\0\0\0" + +def print_static_u8_array_definition(name, value): + print('') + print(f'static const u8 {name}[] __initconst __maybe_unused = {{') + for i in range(0, len(value), 8): + line = '\t' + ''.join(f'0x{b:02x}, ' for b in value[i:i+8]) + print(f'{line.rstrip()}') + print('};') + +print('/* SPDX-License-Identifier: GPL-2.0-or-later */') +print(f'/* This file was generated by: gen-fips-testvecs.py */') +print() +print('#include ') + +print_static_u8_array_definition("fips_test_data", fips_test_data) +print_static_u8_array_definition("fips_test_key", fips_test_key) + +for alg in 'sha1', 'sha256', 'sha512': + ctx = hmac.new(fips_test_key, digestmod=alg) + ctx.update(fips_test_data) + print_static_u8_array_definition(f'fips_test_hmac_{alg}_value', ctx.digest()) -- cgit