From 3f8bbe23cf07f18c4427f571246e7e65c6e767c7 Mon Sep 17 00:00:00 2001
From: Samuel Chiang <sachiang@amazon.com>
Date: Thu, 16 Jan 2025 02:49:44 +0000
Subject: [PATCH] Align BN_bn2hex behavior with OpenSSL

---
 crypto/bn_extra/convert.c       | 2 +-
 crypto/fipsmodule/bn/bn_test.cc | 4 ++--
 crypto/fipsmodule/ec/ec_test.cc | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/crypto/bn_extra/convert.c b/crypto/bn_extra/convert.c
index 7a02e105f5..f863dd6ae6 100644
--- a/crypto/bn_extra/convert.c
+++ b/crypto/bn_extra/convert.c
@@ -74,7 +74,7 @@ int BN_bn2cbb_padded(CBB *out, size_t len, const BIGNUM *in) {
   return CBB_add_space(out, &ptr, len) && BN_bn2bin_padded(ptr, len, in);
 }
 
-static const char hextable[] = "0123456789abcdef";
+static const char hextable[] = "0123456789ABCDEF";
 
 char *BN_bn2hex(const BIGNUM *bn) {
   int width = bn_minimal_width(bn);
diff --git a/crypto/fipsmodule/bn/bn_test.cc b/crypto/fipsmodule/bn/bn_test.cc
index b14a86725b..8e747722e2 100644
--- a/crypto/fipsmodule/bn/bn_test.cc
+++ b/crypto/fipsmodule/bn/bn_test.cc
@@ -2682,7 +2682,7 @@ TEST_F(BNTest, NonMinimal) {
     EXPECT_FALSE(BN_is_pow2(ten.get()));
 
     bssl::UniquePtr<char> hex(BN_bn2hex(ten.get()));
-    EXPECT_STREQ("0a", hex.get());
+    EXPECT_STREQ("0A", hex.get());
     hex.reset(BN_bn2hex(zero.get()));
     EXPECT_STREQ("0", hex.get());
 
@@ -2695,7 +2695,7 @@ TEST_F(BNTest, NonMinimal) {
     // TODO(davidben): |BN_print| removes leading zeros within a byte, while
     // |BN_bn2hex| rounds up to a byte, except for zero which it prints as
     // "0". Fix this discrepancy?
-    EXPECT_EQ(Bytes("a"), Bytes(ptr, len));
+    EXPECT_EQ(Bytes("A"), Bytes(ptr, len));
 
     bio.reset(BIO_new(BIO_s_mem()));
     ASSERT_TRUE(bio);
diff --git a/crypto/fipsmodule/ec/ec_test.cc b/crypto/fipsmodule/ec/ec_test.cc
index b65d53215b..d5c5ad9b91 100644
--- a/crypto/fipsmodule/ec/ec_test.cc
+++ b/crypto/fipsmodule/ec/ec_test.cc
@@ -179,10 +179,10 @@ TEST(ECTest, Encoding) {
   ASSERT_TRUE(y_hex);
 
   EXPECT_STREQ(
-      "c81561ecf2e54edefe6617db1c7a34a70744ddb261f269b83dacfcd2ade5a681",
+      "C81561ECF2E54EDEFE6617DB1C7A34A70744DDB261F269B83DACFCD2ADE5A681",
       x_hex.get());
   EXPECT_STREQ(
-      "e0e2afa3f9b6abe4c698ef6495f1be49a3196c5056acb3763fe4507eec596e88",
+      "E0E2AFA3F9B6ABE4C698EF6495F1BE49A3196C5056ACB3763FE4507EEC596E88",
       y_hex.get());
 }