Especially for a sequence of similar lines of test code, or where the result of
an expression is being compared to a short integer (especially 0 or 1).
Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
The unit tests were created by capturing runs of the existing function during
execution of existing unit tests.
Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
The test cases use the following MPI values:
0 1 fffe ffffffff 100000000 20000000000000 ffffffffffffffff
10000000000000000 1234567890abcdef0 fffffffffffffffffefefefefefefefe
100000000000000000000000000000000 1234567890abcdef01234567890abcdef0
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
1234567890abcdef01234567890abcdef01234567890abcdef01234567890abcdef0
4df72d07b4b71c8dacb6cffa954f8d88254b6277099308baf003fab73227f34029643b5a263f66e0d3c3fa297ef71755efd53b8fb6cb812c6bbf7bcf179298bd9947c4c8b14324140a2c0f5fad7958a69050a987a6096e9f055fb38edf0c5889eca4a0cfa99b45fbdeee4c696b328ddceae4723945901ec025076b12b
and the following scalars. The .data files include two sets of results (final
accumulator and carry) for the cases sizeof(mbedtls_mpi_uint) == 4 or 8.
0 3 fe ff ffff 10000 ffffffff 100000000 7f7f7f7f7f7f7f7f 8000000000000000
fffffffffffffffe
The lines in the .data file were generated by the following script
#!/usr/bin/env perl
#
# mpi-test-core-mla.pl - generate/run MPI tests in Perl for mbedtls_mpi_core_mla()
#
use strict;
use warnings;
use Math::BigInt;
use sort 'stable';
my @mla_mpis = qw(
0 1 fffe ffffffff 100000000 20000000000000 ffffffffffffffff
10000000000000000 1234567890abcdef0 fffffffffffffffffefefefefefefefe
100000000000000000000000000000000 1234567890abcdef01234567890abcdef0
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
1234567890abcdef01234567890abcdef01234567890abcdef01234567890abcdef0
4df72d07b4b71c8dacb6cffa954f8d88254b6277099308baf003fab73227f34029643b5a263f66e0d3c3fa297ef71755efd53b8fb6cb812c6bbf7bcf179298bd9947c4c8b14324140a2c0f5fad7958a69050a987a6096e9f055fb38edf0c5889eca4a0cfa99b45fbdeee4c696b328ddceae4723945901ec025076b12b
);
my @mla_scalars = qw(
0 3 fe ff ffff 10000 ffffffff 100000000 7f7f7f7f7f7f7f7f 8000000000000000
fffffffffffffffe
);
my @mla_full_mpis = qw(
0 1 3 f fe ff 100 ff00 fffe ffff 10000
fffffffe ffffffff 100000000 1f7f7f7f7f7f7f
8000000000000000 fefefefefefefefe fffffffffffffffe ffffffffffffffff
10000000000000000 1234567890abcdef0
fffffffffffffffffefefefefefefefe fffffffffffffffffffffffffffffffe ffffffffffffffffffffffffffffffff
100000000000000000000000000000000 1234567890abcdef01234567890abcdef0
fffffffffffffffffffffffffffffffffffffffffffffffffefefefefefefefe
fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
10000000000000000000000000000000000000000000000000000000000000000
1234567890abcdef01234567890abcdef01234567890abcdef01234567890abcdef0
4df72d07b4b71c8dacb6cffa954f8d88254b6277099308baf003fab73227f34029643b5a263f66e0d3c3fa297ef71755efd53b8fb6cb812c6bbf7bcf179298bd9947c4c8b14324140a2c0f5fad7958a69050a987a6096e9f055fb38edf0c5889eca4a0cfa99b45fbdeee4c696b328ddceae4723945901ec025076b12b
);
my @mla_full_scalars = qw(
0 1 3 f fe ff 100 ff00 fffe ffff 10000
fffffffe ffffffff 100000000
8000000000000000 fefefefefefefefe fffffffffffffffe ffffffffffffffff
);
generate_tests();
sub generate_tests {
generate_mbedtls_mpi_core_mla();
}
sub generate_mbedtls_mpi_core_mla {
my $sub_name = (caller(0))[3]; # e.g. main::generate_mbedtls_mpi_sub_mpi
my ($ignore, $test_name) = split("main::generate_", $sub_name);
my @cases = ();
for my $ah (@mla_mpis) {
for my $bh (@mla_mpis) {
for my $ch (@mla_scalars) {
# a += b * c (c is scalar)
# a_len >= b_len. need carry out.
my $a = Math::BigInt->from_hex($ah);
my $b = Math::BigInt->from_hex($bh);
my $c = Math::BigInt->from_hex($ch);
my $max = ($a > $b) ? $a : $b;
my $bound4 = bound_mpi4($max);
my $bound8 = bound_mpi8($max);
my $r = $a + $b * $c;
my ($r4, $cy4) = ($r->copy(), 0);
my ($r8, $cy8) = ($r->copy(), 0);
($cy4, $r4) = $r4->bdiv($bound4);
($cy8, $r8) = $r8->bdiv($bound8);
my $rh4 = $r4->to_hex();
my $rh8 = $r8->to_hex();
my $cyh4 = $cy4->to_hex();
my $cyh8 = $cy8->to_hex();
# If the scalar c is too big for 1 x 4-byte MPI, we can only run this test on a system with 8-byte MPIs
my $depends = mpi4s($c) > 1 ? "MBEDTLS_HAVE_INT64" : "";
my $desc = "$test_name #NUMBER: 0x$ah + 0x$bh * 0x$ch = (0x$rh4, carry 0x$cyh4)/(0x$rh8, carry 0x$cyh8)EXPLAIN";
my $case = output($test_name, str($ah), str($bh), str($ch), str($rh4), str($cyh4), str($rh8), str($cyh8));
push(@cases, [$case, $desc, $depends]);
}
}
}
output_cases(" (for when sizeof(mbedtls_mpi_uint) == 4/8)", @cases);
}
sub output_cases {
my ($explain, @cases) = @_;
my $count = 1;
for my $c (@cases) {
my ($case, $desc, $dep) = @$c;
$desc =~ s/NUMBER/$count/; $count++;
if (defined($explain) && $desc =~ /EXPLAIN/) {
$desc =~ s/EXPLAIN/$explain/;
$explain = "";
}
my $depends = "";
$depends = "depends_on:$dep\n" if defined($dep) && length($dep);
print <<EOF;
$desc
$depends$case
EOF
}
}
# The first number (a power of 2) that won't fit in the number of MPIs
# needed for the given number
sub bound_mpi4 {
my $one = Math::BigInt->new(1); # blsft modifies caller
return $one->blsft(bits_mpi4($_[0]));
}
sub bound_mpi8 {
my $one = Math::BigInt->new(1); # blsft modifies caller
return $one->blsft(bits_mpi8($_[0]));
}
# How many bits (a multiple of 32) needed to store the specified number
# when using 4-byte MPIs
sub bits_mpi4 {
return 32 * mpi4s($_[0]);
}
# How many bits (a multiple of 64) needed to store the specified number
# when using 8-byte MPIs
sub bits_mpi8 {
return 64 * mpi8s($_[0]);
}
# How many 4-byte MPIs needed to store the specified number
sub mpi4s {
my ($n) = @_;
my $h = $n->to_hex();
return int((length($h) + 7) / 8);
}
# How many 8-byte MPIs needed to store the specified number
sub mpi8s {
my ($n) = @_;
my $h = $n->to_hex();
return int((length($h) + 15) / 16);
}
sub output {
#run_test(@_);
return join(":", @_);
}
sub str {
return '"' . $_[0] . '"';
}
Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
The test cases use the following MPI values.
The .data file includes two results, for the cases when
sizeof(mbedtls_mpi_uint) == 4 or 8.
0 1 3 f fe ff 100 ff00 fffe ffff 10000
fffffffe ffffffff 100000000 1f7f7f7f7f7f7f
8000000000000000 fefefefefefefefe fffffffffffffffe ffffffffffffffff
10000000000000000 1234567890abcdef0
fffffffffffffffffefefefefefefefe fffffffffffffffffffffffffffffffe
ffffffffffffffffffffffffffffffff 100000000000000000000000000000000
1234567890abcdef01234567890abcdef0
fffffffffffffffffffffffffffffffffffffffffffffffffefefefefefefefe
fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
10000000000000000000000000000000000000000000000000000000000000000
1234567890abcdef01234567890abcdef01234567890abcdef01234567890abcdef0
4df72d07b4b71c8dacb6cffa954f8d88254b6277099308baf003fab73227f34029643b5a263f66e0d3c3fa297ef71755efd53b8fb6cb812c6bbf7bcf179298bd9947c4c8b14324140a2c0f5fad7958a69050a987a6096e9f055fb38edf0c5889eca4a0cfa99b45fbdeee4c696b328ddceae4723945901ec025076b12b
The lines in the .data file were generated by the following script
#!/usr/bin/env perl
#
# mpi-test-core-sub.pl - generate/run MPI tests in Perl for mbedtls_mpi_core_sub()
#
use strict;
use warnings;
use Math::BigInt;
use sort 'stable';
my @sub_mpis = qw(
0 1 3 f fe ff 100 ff00 fffe ffff 10000
fffffffe ffffffff 100000000 1f7f7f7f7f7f7f
8000000000000000 fefefefefefefefe fffffffffffffffe ffffffffffffffff
10000000000000000 1234567890abcdef0
fffffffffffffffffefefefefefefefe fffffffffffffffffffffffffffffffe ffffffffffffffffffffffffffffffff
100000000000000000000000000000000 1234567890abcdef01234567890abcdef0
fffffffffffffffffffffffffffffffffffffffffffffffffefefefefefefefe
fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
10000000000000000000000000000000000000000000000000000000000000000
1234567890abcdef01234567890abcdef01234567890abcdef01234567890abcdef0
4df72d07b4b71c8dacb6cffa954f8d88254b6277099308baf003fab73227f34029643b5a263f66e0d3c3fa297ef71755efd53b8fb6cb812c6bbf7bcf179298bd9947c4c8b14324140a2c0f5fad7958a69050a987a6096e9f055fb38edf0c5889eca4a0cfa99b45fbdeee4c696b328ddceae4723945901ec025076b12b
);
generate_tests();
sub generate_tests {
generate_mbedtls_mpi_core_sub();
}
sub generate_mbedtls_mpi_core_sub {
my $sub_name = (caller(0))[3]; # e.g. main::generate_mbedtls_mpi_sub_mpi
my ($ignore, $test_name) = split("main::generate_", $sub_name);
my @cases = ();
for my $ah (@sub_mpis) {
for my $bh (@sub_mpis) {
my $a = Math::BigInt->from_hex($ah);
my $b = Math::BigInt->from_hex($bh);
my ($rh4, $rh8, $carry);
if ($a >= $b) {
my $r = $a - $b;
$rh4 = $rh8 = $r->to_hex();
$carry = 0;
} else {
my $r4 = bound_mpi4($b) + $a - $b;
my $r8 = bound_mpi8($b) + $a - $b;
$rh4 = $r4->to_hex();
$rh8 = $r8->to_hex();
$carry = 1;
}
my $desc = "$test_name #NUMBER: 0x$ah - 0x$bh = 0x$rh4/${rh8}EXPLAIN, carry ${carry}";
my $case = output($test_name, str($ah), str($bh), str($rh4), str($rh8), $carry);
push(@cases, [$case, $desc]);
}
}
output_cases(" (for when sizeof(mbedtls_mpi_uint) == 4/8)", @cases);
}
sub output_cases {
my ($explain, @cases) = @_;
my $count = 1;
for my $c (@cases) {
my ($case, $desc, $dep) = @$c;
$desc =~ s/NUMBER/$count/; $count++;
if (defined($explain) && $desc =~ /EXPLAIN/) {
$desc =~ s/EXPLAIN/$explain/;
$explain = "";
}
my $depends = "";
$depends = "depends_on:$dep\n" if defined($dep) && length($dep);
print <<EOF;
$desc
$depends$case
EOF
}
}
# The first number (a power of 2) that won't fit in the number of MPIs
# needed for the given number
sub bound_mpi4 {
my $one = Math::BigInt->new(1); # blsft modifies caller
return $one->blsft(bits_mpi4($_[0]));
}
sub bound_mpi8 {
my $one = Math::BigInt->new(1); # blsft modifies caller
return $one->blsft(bits_mpi8($_[0]));
}
# How many bits (a multiple of 32) needed to store the specified number
# when using 4-byte MPIs
sub bits_mpi4 {
return 32 * mpi4s($_[0]);
}
# How many bits (a multiple of 64) needed to store the specified number
# when using 8-byte MPIs
sub bits_mpi8 {
return 64 * mpi8s($_[0]);
}
# How many 4-byte MPIs needed to store the specified number
sub mpi4s {
my ($n) = @_;
my $h = $n->to_hex();
return int((length($h) + 7) / 8);
}
# How many 8-byte MPIs needed to store the specified number
sub mpi8s {
my ($n) = @_;
my $h = $n->to_hex();
return int((length($h) + 15) / 16);
}
sub output {
return join(":", @_);
}
sub str {
return '"' . $_[0] . '"';
}
Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
The test cases use the following MPI values.
The .data file only includes those (a, b) values where a <= b, and gives the
sum unconditionally; the test code exercises a >= b and cond == 0 using these
values. The .data file gives two values for the carry out, which are for when
sizeof(mbedtls_mpi_uint) == 4 or 8.
0 1 3 f fe ff 100 ff00 fffe ffff 10000
fffffffe ffffffff 100000000 1f7f7f7f7f7f7f
8000000000000000 fefefefefefefefe fffffffffffffffe ffffffffffffffff
10000000000000000 1234567890abcdef0
fffffffffffffffffefefefefefefefe fffffffffffffffffffffffffffffffe
ffffffffffffffffffffffffffffffff 100000000000000000000000000000000
1234567890abcdef01234567890abcdef0
fffffffffffffffffffffffffffffffffffffffffffffffffefefefefefefefe
fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
10000000000000000000000000000000000000000000000000000000000000000
1234567890abcdef01234567890abcdef01234567890abcdef01234567890abcdef0
4df72d07b4b71c8dacb6cffa954f8d88254b6277099308baf003fab73227f34029643b5a263f66e0d3c3fa297ef71755efd53b8fb6cb812c6bbf7bcf179298bd9947c4c8b14324140a2c0f5fad7958a69050a987a6096e9f055fb38edf0c5889eca4a0cfa99b45fbdeee4c696b328ddceae4723945901ec025076b12b
The lines in the .data file were generated by the following script
```
#!/usr/bin/env perl
#
# mpi-test-core-add-if.pl - generate MPI tests in Perl for mbedtls_mpi_core_add_if()
#
use strict;
use warnings;
use Math::BigInt;
use sort 'stable';
my @add_mpis = qw(
0 1 3 f fe ff 100 ff00 fffe ffff 10000
fffffffe ffffffff 100000000 1f7f7f7f7f7f7f
8000000000000000 fefefefefefefefe fffffffffffffffe ffffffffffffffff
10000000000000000 1234567890abcdef0
fffffffffffffffffefefefefefefefe fffffffffffffffffffffffffffffffe ffffffffffffffffffffffffffffffff
100000000000000000000000000000000 1234567890abcdef01234567890abcdef0
fffffffffffffffffffffffffffffffffffffffffffffffffefefefefefefefe
fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
10000000000000000000000000000000000000000000000000000000000000000
1234567890abcdef01234567890abcdef01234567890abcdef01234567890abcdef0
4df72d07b4b71c8dacb6cffa954f8d88254b6277099308baf003fab73227f34029643b5a263f66e0d3c3fa297ef71755efd53b8fb6cb812c6bbf7bcf179298bd9947c4c8b14324140a2c0f5fad7958a69050a987a6096e9f055fb38edf0c5889eca4a0cfa99b45fbdeee4c696b328ddceae4723945901ec025076b12b
);
generate_tests();
sub generate_tests {
generate_mbedtls_mpi_core_add_if();
}
sub generate_mbedtls_mpi_core_add_if {
my $sub_name = (caller(0))[3]; # e.g. main::generate_mbedtls_mpi_add_mpi
my ($ignore, $test_name) = split("main::generate_", $sub_name);
my @cases = ();
for my $ah (@add_mpis) {
for my $bh (@add_mpis) {
my $a = Math::BigInt->from_hex($ah);
my $b = Math::BigInt->from_hex($bh);
next if $a > $b; # don't need to repeat test cases
# $b is the larger (or equal) of the two numbers. That's the number of limbs
# we'll be using.
my $bound4 = bound_mpi4($b);
my $bound8 = bound_mpi8($b);
my $r = $a + $b;
my ($r4, $carry4) = ($r->copy(), 0);
my ($r8, $carry8) = ($r->copy(), 0);
($carry4, $r4) = $r4->bdiv($bound4);
($carry8, $r8) = $r8->bdiv($bound8);
my $rh4 = $r4->to_hex();
my $rh8 = $r8->to_hex();
my $desc = "$test_name #NUMBER: 0x$ah + 0x$bh = (0x$rh4, carry $carry4)/(0x$rh8, carry $carry8)EXPLAIN";
my $case = output($test_name, str($ah), str($bh), str($rh4), $carry4, str($rh8), $carry8);
push(@cases, [$case, $desc]);
}
}
output_cases(" (for when sizeof(mbedtls_mpi_uint) == 4/8)", @cases);
}
sub output_cases {
my ($explain, @cases) = @_;
my $count = 1;
for my $c (@cases) {
my ($case, $desc, $dep) = @$c;
$desc =~ s/NUMBER/$count/; $count++;
if (defined($explain) && $desc =~ /EXPLAIN/) {
$desc =~ s/EXPLAIN/$explain/;
$explain = "";
}
my $depends = "";
$depends = "depends_on:$dep\n" if defined($dep) && length($dep);
print <<EOF;
$desc
$depends$case
EOF
}
}
# The first number (a power of 2) that won't fit in the number of MPIs
# needed for the given number
sub bound_mpi4 {
my $one = Math::BigInt->new(1); # blsft modifies caller
return $one->blsft(bits_mpi4($_[0]));
}
sub bound_mpi8 {
my $one = Math::BigInt->new(1); # blsft modifies caller
return $one->blsft(bits_mpi8($_[0]));
}
# How many bits (a multiple of 32) needed to store the specified number
# when using 4-byte MPIs
sub bits_mpi4 {
return 32 * mpi4s($_[0]);
}
# How many bits (a multiple of 64) needed to store the specified number
# when using 8-byte MPIs
sub bits_mpi8 {
return 64 * mpi8s($_[0]);
}
# How many 4-byte MPIs needed to store the specified number
sub mpi4s {
my ($n) = @_;
my $h = $n->to_hex();
return int((length($h) + 7) / 8);
}
# How many 8-byte MPIs needed to store the specified number
sub mpi8s {
my ($n) = @_;
my $h = $n->to_hex();
return int((length($h) + 15) / 16);
}
sub output {
return join(":", @_);
}
sub str {
return '"' . $_[0] . '"';
}
```
Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
TEST_EQUAL(), has the benefit of outputting the values that don't match,
which can make debugging simpler.
Scope:
- Recently added new test functions
- Checks making sure the test case/data is consistent is out of scope
- Only checks where printing the values is likely to be helpful
Signed-off-by: Janos Follath <janos.follath@arm.com>
- Improve test descriptions
- Add more test cases with return value of 1
- Remove the mbedtls prefix from the test function
Signed-off-by: Janos Follath <janos.follath@arm.com>
- Instead of macros, use direct calculations for array sizes
- Move variable declarations closer to first use
Signed-off-by: Janos Follath <janos.follath@arm.com>
Unfortunately reusing the new function from the signed constant time
comparison is not trivial.
One option would be to do temporary conditional swaps which would prevent
qualifying input to const. Another way would be to add an additional
flag for the sign and make it an integral part of the computation, which
would defeat the purpose of having an unsigned core comparison.
Going with two separate function for now and the signed version can be
retired/compiled out with the legacy API eventually.
The new function in theory could be placed into either
`library/constant_time.c` or `library/bignum_new.c`. Going with the
first as the other functions in the second are not constant time yet and
this distinction seems more valuable for new (as opposed to belonging to
the `_core` functions.
Signed-off-by: Janos Follath <janos.follath@arm.com>
- We don't check for NULL pointers this deep in the library
- Accessing a NULL pointer when the limb number is 0 as a mistake is the
very similar to any other out of bounds access
- We could potentially mandate at least 1 limb representation for 0 but
we either would need to enforce it or the implementation would be less
robust.
- Allowing zero limb representation - (NULL, 0) in particular - for zero
is present in the legacy interface, if we disallow it, the
compatibility code will need to deal with this (more code size and
opportunities for mistakes)
In summary, interpreting (NULL, 0) as the number zero in the core
interface is the least of the two evils.
Signed-off-by: Janos Follath <janos.follath@arm.com>
The test case where there were extra limbs in the MPI failed and this
commit contains the corresponding fix as well. (We used to use the
minimum required limbs instead of the actual limbs present.)
Signed-off-by: Janos Follath <janos.follath@arm.com>
Test data which is compared as a hex string now uses upper case to
match output of mbedtls_mpi_write_string() output. This removes usage
of strcasecmp().
Signed-off-by: Werner Lewis <werner.lewis@arm.com>
Cases where radix was explictly declared are removed in most cases,
replaced using script. bignum arguments are represented as hexadecimal
strings. This reduces clutter in test data and makes bit patterns
clearer.
Signed-off-by: Werner Lewis <werner.lewis@arm.com>
No need to bypass the API to fill limbs. It's a better test to just
set the top bit that we want to have set, and it's one less bypass of
the API.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Test both 0 represented with 0 limbs ("0 (null)") and 0 represented
with 1 limb ("0 (1 limb)"), because occasionally there are bugs with
0-limb bignums and occasionally there are bugs with removing leading
zero limbs.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
mbedtls_mpi_exp_mod can be called in three ways regarding the speed-up
parameter _RR: null (unused), zero (will be updated), nonzero (will be
used). Systematically test all three.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
