From 2f8b09c72538a43f0bb266811fc6c701173d1fee Mon Sep 17 00:00:00 2001 From: Gilles Peskine Date: Thu, 14 Apr 2022 12:00:17 +0200 Subject: [PATCH] Don't test with all-but-one elliptic curves `curves.pl` (invoked by `all.sh test_depends_curves`, and `all.sh test_depends_curves_psa`) currently runs two series of tests: * For each curve, test with only that curve enabled. * For each curve, test with all curves but that one. Originally this script was introduced to validate test dependencies, and for that all-but-one gives better results because it handles test cases that require multiple curves. Then we extended the script to also test with a single curve, which matches many real-world setups and catches some product bugs. Single-curve testing also validates test dependencies in a more limited way. Remove all-but-one curve testing, because it doesn't add much to the test coverage. Mainly, this means that we now won't detect if a test case declares two curve dependencies but actually also depends on a third. This is an acceptable loss. The trigger for removing all-but-one curve testing is that this will make the job take only about half as long, and the length of the job was a bit of a problem. Resolves #5729. Signed-off-by: Gilles Peskine --- tests/scripts/curves.pl | 51 +++++++++++++---------------------------- 1 file changed, 16 insertions(+), 35 deletions(-) diff --git a/tests/scripts/curves.pl b/tests/scripts/curves.pl index 188bd29ac..08582dc74 100755 --- a/tests/scripts/curves.pl +++ b/tests/scripts/curves.pl @@ -20,18 +20,24 @@ # Purpose # # The purpose of this test script is to validate that the library works -# with any combination of elliptic curves. To this effect, build the library -# and run the test suite with each tested combination of elliptic curves. +# when only a single curve is enabled. In particular, this validates that +# curve-specific code is guarded by the proper preprocessor conditionals, +# both in the library and in tests. # -# Testing all 2^n combinations would be too much, so we only test 2*n: +# Since this script only tests builds with a single curve, it can't detect +# bugs that are only triggered when multiple curves are present. We do +# also test in many configurations where all curves are enabled, as well +# as a few configurations in configs/*.h with a restricted subset of curves. # -# 1. Test with a single curve, for each curve. This validates that the -# library works with any curve, and in particular that curve-specific -# code is guarded by the proper preprocessor conditionals. -# 2. Test with all curves except one, for each curve. This validates that -# the test cases have correct dependencies. Testing with a single curve -# doesn't validate this for tests that require more than one curve. - +# Here are some known test gaps that could be addressed by testing all +# 2^n combinations of support for n curves, which is impractical: +# * There could be product bugs when curves A and B are enabled but not C. +# For example, a MAX_SIZE calculation that forgets B, where +# size(A) < size(B) < size(C). +# * For test cases that require three or more curves, validate that they're +# not missing dependencies. This is extremely rare. (For test cases that +# require curves A and B but are missing a dependency on B, this is +# detected in the A-only build.) # Usage: tests/scripts/curves.pl # # This script should be executed from the root of the project directory. @@ -114,31 +120,6 @@ for my $curve (@curves) { and abort "Failed to disable $curve\n"; } -system( "cp $config_h.bak $config_h" ) and die "$config_h not restored\n"; - -# Test with $curve disabled but the others enabled, for each $curve. -for my $curve (@curves) { - system( "cp $config_h.bak $config_h" ) and die "$config_h not restored\n"; - system( "make clean" ) and die; - - # depends on a specific curve. Also, ignore error if it wasn't enabled - system( "scripts/config.py unset MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED" ); - - print "\n******************************************\n"; - print "* Testing without curve: $curve\n"; - print "******************************************\n"; - $ENV{MBEDTLS_TEST_CONFIGURATION} = "-$curve"; - - system( "scripts/config.py unset $curve" ) - and abort "Failed to disable $curve\n"; - - system( "CFLAGS='-Werror -Wall -Wextra' make" ) - and abort "Failed to build: all but $curve\n"; - system( "make test" ) - and abort "Failed test suite: all but $curve\n"; - -} - system( "mv $config_h.bak $config_h" ) and die "$config_h not restored\n"; system( "make clean" ) and die; exit 0;