Test |BN_uadd| and |BN_usub|.
Also, update the documentation about aliasing for |BN_usub|. It might
be better to find a way to factor out the shared logic between the
tests of these functions and the tests of |BN_add| and |BN_usub|, but
doing so would end up up creating a lot of parameters due to the many
distinct strings used in the messages.
Change-Id: Ic9d714858212fc92aa6bbcc3959576fe6bbf58c3
Reviewed-on: https://boringssl-review.googlesource.com/8593
Reviewed-by: David Benjamin <davidben@google.com>
diff --git a/crypto/bn/bn_test.cc b/crypto/bn/bn_test.cc
index 6248aaa..fe6e0b7 100644
--- a/crypto/bn/bn_test.cc
+++ b/crypto/bn/bn_test.cc
@@ -336,6 +336,46 @@
return false;
}
+ // Test |BN_uadd| and |BN_usub| with the prerequisites they are documented as
+ // having. Note that these functions are frequently used when the
+ // prerequisites don't hold. In those cases, they are supposed to work as if
+ // the prerequisite hold, but we don't test that yet. TODO: test that.
+ if (!BN_is_negative(a.get()) &&
+ !BN_is_negative(b.get()) && BN_cmp(a.get(), b.get()) >= 0) {
+ if (!BN_uadd(ret.get(), a.get(), b.get()) ||
+ !ExpectBIGNUMsEqual(t, "A +u B", sum.get(), ret.get()) ||
+ !BN_usub(ret.get(), sum.get(), a.get()) ||
+ !ExpectBIGNUMsEqual(t, "Sum -u A", b.get(), ret.get()) ||
+ !BN_usub(ret.get(), sum.get(), b.get()) ||
+ !ExpectBIGNUMsEqual(t, "Sum -u B", a.get(), ret.get())) {
+ return false;
+ }
+
+ // Test that the functions work when |r| and |a| point to the same |BIGNUM|,
+ // or when |r| and |b| point to the same |BIGNUM|. TODO: Test the case where
+ // all of |r|, |a|, and |b| point to the same |BIGNUM|.
+ if (!BN_copy(ret.get(), a.get()) ||
+ !BN_uadd(ret.get(), ret.get(), b.get()) ||
+ !ExpectBIGNUMsEqual(t, "A +u B (r is a)", sum.get(), ret.get()) ||
+ !BN_copy(ret.get(), b.get()) ||
+ !BN_uadd(ret.get(), a.get(), ret.get()) ||
+ !ExpectBIGNUMsEqual(t, "A +u B (r is b)", sum.get(), ret.get()) ||
+ !BN_copy(ret.get(), sum.get()) ||
+ !BN_usub(ret.get(), ret.get(), a.get()) ||
+ !ExpectBIGNUMsEqual(t, "Sum -u A (r is a)", b.get(), ret.get()) ||
+ !BN_copy(ret.get(), a.get()) ||
+ !BN_usub(ret.get(), sum.get(), ret.get()) ||
+ !ExpectBIGNUMsEqual(t, "Sum -u A (r is b)", b.get(), ret.get()) ||
+ !BN_copy(ret.get(), sum.get()) ||
+ !BN_usub(ret.get(), ret.get(), b.get()) ||
+ !ExpectBIGNUMsEqual(t, "Sum -u B (r is a)", a.get(), ret.get()) ||
+ !BN_copy(ret.get(), b.get()) ||
+ !BN_usub(ret.get(), sum.get(), ret.get()) ||
+ !ExpectBIGNUMsEqual(t, "Sum -u B (r is b)", a.get(), ret.get())) {
+ return false;
+ }
+ }
+
// Test with |BN_add_word| and |BN_sub_word| if |b| is small enough.
BN_ULONG b_word = BN_get_word(b.get());
if (!BN_is_negative(b.get()) && b_word != (BN_ULONG)-1) {
