From c9065c32cae60fdc4cce4344f4bfc416ece1bef1 Mon Sep 17 00:00:00 2001
From: Marcus Burghardt <marcus.apb@gmail.com>
Date: Mon, 13 May 2019 17:00:00 +0000
Subject: [PATCH] Bug 1509432 - Removed duplicated code between mp_set_int and
 mp_set_ulong. Created a gtest for this functions. r=KevinJacobs

Differential Revision: https://phabricator.services.mozilla.com/D30870

--HG--
extra : moz-landing-system : lando
---
 gtests/freebl_gtest/mpi_unittest.cc | 35 +++++++++++++++++++++++++++++
 lib/freebl/mpi/mpi.c                | 26 +++++----------------
 2 files changed, 41 insertions(+), 20 deletions(-)

diff --git a/gtests/freebl_gtest/mpi_unittest.cc b/gtests/freebl_gtest/mpi_unittest.cc
index b0944975ef..57f5480db0 100644
--- a/gtests/freebl_gtest/mpi_unittest.cc
+++ b/gtests/freebl_gtest/mpi_unittest.cc
@@ -148,6 +148,41 @@ TEST_F(MPITest, MpiCmpUnalignedTest) {
 }
 #endif
 
+// The two follow tests ensure very similar mp_set_* functions are ok.
+TEST_F(MPITest, MpiSetUlong) {
+    mp_int a, b, c;
+    MP_DIGITS(&a) = 0;
+    MP_DIGITS(&b) = 0;
+    MP_DIGITS(&c) = 0;
+    ASSERT_EQ(MP_OKAY, mp_init(&a));
+    ASSERT_EQ(MP_OKAY, mp_init(&b));
+    ASSERT_EQ(MP_OKAY, mp_init(&c));
+    EXPECT_EQ(MP_OKAY, mp_set_ulong(&a, 1));
+    EXPECT_EQ(MP_OKAY, mp_set_ulong(&b, 0));
+    EXPECT_EQ(MP_OKAY, mp_set_ulong(&c, -1));
+
+    mp_clear(&a);
+    mp_clear(&b);
+    mp_clear(&c);
+}
+
+TEST_F(MPITest, MpiSetInt) {
+    mp_int a, b, c;
+    MP_DIGITS(&a) = 0;
+    MP_DIGITS(&b) = 0;
+    MP_DIGITS(&c) = 0;
+    ASSERT_EQ(MP_OKAY, mp_init(&a));
+    ASSERT_EQ(MP_OKAY, mp_init(&b));
+    ASSERT_EQ(MP_OKAY, mp_init(&c));
+    EXPECT_EQ(MP_OKAY, mp_set_int(&a, 1));
+    EXPECT_EQ(MP_OKAY, mp_set_int(&b, 0));
+    EXPECT_EQ(MP_OKAY, mp_set_int(&c, -1));
+
+    mp_clear(&a);
+    mp_clear(&b);
+    mp_clear(&c);
+}
+
 TEST_F(MPITest, MpiFixlenOctetsZero) {
   std::vector<uint8_t> zero = {0};
   TestToFixedOctets(zero, 1);
diff --git a/lib/freebl/mpi/mpi.c b/lib/freebl/mpi/mpi.c
index 401eac51db..9e72ac1bde 100644
--- a/lib/freebl/mpi/mpi.c
+++ b/lib/freebl/mpi/mpi.c
@@ -341,33 +341,19 @@ mp_set(mp_int *mp, mp_digit d)
 mp_err
 mp_set_int(mp_int *mp, long z)
 {
-    int ix;
     unsigned long v = labs(z);
     mp_err res;
 
-    ARGCHK(mp != NULL, MP_BADARG);
-
-    mp_zero(mp);
-    if (z == 0)
-        return MP_OKAY; /* shortcut for zero */
-
-    if (sizeof v <= sizeof(mp_digit)) {
-        DIGIT(mp, 0) = v;
-    } else {
-        for (ix = sizeof(long) - 1; ix >= 0; ix--) {
-            if ((res = s_mp_mul_d(mp, (UCHAR_MAX + 1))) != MP_OKAY)
-                return res;
-
-            res = s_mp_add_d(mp, (mp_digit)((v >> (ix * CHAR_BIT)) & UCHAR_MAX));
-            if (res != MP_OKAY)
-                return res;
-        }
+    /* https://bugzilla.mozilla.org/show_bug.cgi?id=1509432 */
+    if ((res = mp_set_ulong(mp, v)) != MP_OKAY) { /* avoids duplicated code */
+        return res;
     }
-    if (z < 0)
+
+    if (z < 0) {
         SIGN(mp) = NEG;
+    }
 
     return MP_OKAY;
-
 } /* end mp_set_int() */
 
 /* }}} */