diff --git a/crypto/pkcs7/bio/bio_md_test.cc b/crypto/pkcs7/bio/bio_md_test.cc
index e7572c9935..eb1f93cdc8 100644
--- a/crypto/pkcs7/bio/bio_md_test.cc
+++ b/crypto/pkcs7/bio/bio_md_test.cc
@@ -104,7 +104,8 @@ TEST_P(BIOMessageDigestTest, Basic) {
   bio.reset(BIO_push(bio_md.get(), bio_mem.get()));
   ASSERT_TRUE(bio);
   EXPECT_TRUE(BIO_write(bio.get(), message, sizeof(message)));
-  unsigned digest_len = BIO_gets(bio_md.get(), (char *)buf, sizeof(buf));
+  int digest_len = BIO_gets(bio_md.get(), (char *)buf, sizeof(buf));
+  ASSERT_GE(digest_len, 0);
   buf_vec.clear();
   buf_vec.insert(buf_vec.begin(), buf, buf + digest_len);
   OPENSSL_memset(buf, '\0', sizeof(buf));
@@ -117,7 +118,7 @@ TEST_P(BIOMessageDigestTest, Basic) {
   ASSERT_TRUE(EVP_DigestInit_ex(ctx.get(), md, NULL));
   ASSERT_TRUE(
       EVP_DigestUpdate(ctx.get(), message_vec.data(), message_vec.size()));
-  ASSERT_TRUE(EVP_DigestFinal_ex(ctx.get(), buf, &digest_len));
+  ASSERT_TRUE(EVP_DigestFinal_ex(ctx.get(), buf, reinterpret_cast<unsigned int*>(&digest_len)));
   EXPECT_EQ(Bytes(buf_vec.data(), buf_vec.size()), Bytes(buf, digest_len));
   bio_md.release();   // |bio| took ownership
   bio_mem.release();  // |bio| took ownership
@@ -138,13 +139,14 @@ TEST_P(BIOMessageDigestTest, Basic) {
   EXPECT_EQ(Bytes(message_vec.data(), message_vec.size()),
             Bytes(message, sizeof(message)));
   digest_len = BIO_gets(bio_md.get(), (char *)buf, sizeof(buf));
+  ASSERT_GE(digest_len, 0);
   buf_vec.clear();
   buf_vec.insert(buf_vec.begin(), buf, buf + digest_len);
   ctx.reset(EVP_MD_CTX_new());
   ASSERT_TRUE(EVP_DigestInit_ex(ctx.get(), md, NULL));
   ASSERT_TRUE(
       EVP_DigestUpdate(ctx.get(), message_vec.data(), message_vec.size()));
-  ASSERT_TRUE(EVP_DigestFinal_ex(ctx.get(), buf, &digest_len));
+  ASSERT_TRUE(EVP_DigestFinal_ex(ctx.get(), buf, reinterpret_cast<unsigned int*>(&digest_len)));
   EXPECT_EQ(Bytes(buf, digest_len), Bytes(buf_vec.data(), buf_vec.size()));
   EXPECT_EQ(Bytes(buf_vec.data(), buf_vec.size()), Bytes(buf, digest_len));
   // Resetting |bio_md| should reset digest state, elicit different digest
@@ -196,9 +198,9 @@ TEST_P(BIOMessageDigestTest, Randomized) {
       message.insert(message.end(), &message_buf[0], &message_buf[io_size]);
     }
     EVP_DigestUpdate(ctx.get(), message.data(), message.size());
-    unsigned digest_size;
-    EVP_DigestFinal_ex(ctx.get(), digest_buf, &digest_size);
-    ASSERT_EQ(EVP_MD_CTX_size(ctx.get()), digest_size);
+    int digest_size;
+    EVP_DigestFinal_ex(ctx.get(), digest_buf, reinterpret_cast<unsigned int*>(&digest_size));
+    ASSERT_EQ(EVP_MD_CTX_size(ctx.get()), (unsigned int)digest_size);
     expected_digest.insert(expected_digest.begin(), &digest_buf[0],
                            &digest_buf[digest_size]);
     OPENSSL_cleanse(digest_buf, sizeof(digest_buf));
@@ -219,7 +221,8 @@ TEST_P(BIOMessageDigestTest, Randomized) {
     }
     digest_size =
         BIO_gets(bio_md.get(), (char *)digest_buf, sizeof(digest_buf));
-    ASSERT_EQ(EVP_MD_CTX_size(ctx.get()), digest_size);
+    ASSERT_GE(digest_size, 0);
+    ASSERT_EQ(EVP_MD_CTX_size(ctx.get()), (unsigned int)digest_size);
     EXPECT_EQ(Bytes(expected_digest.data(), expected_digest.size()),
               Bytes(digest_buf, digest_size));
     OPENSSL_cleanse(digest_buf, sizeof(digest_buf));
@@ -241,7 +244,8 @@ TEST_P(BIOMessageDigestTest, Randomized) {
     EXPECT_TRUE(BIO_eof(bio.get()));
     digest_size =
         BIO_gets(bio_md.get(), (char *)digest_buf, sizeof(digest_buf));
-    ASSERT_EQ(EVP_MD_CTX_size(ctx.get()), digest_size);
+    ASSERT_GE(digest_size, 0);
+    ASSERT_EQ(EVP_MD_CTX_size(ctx.get()), (unsigned int)digest_size);
     EXPECT_EQ(Bytes(expected_digest.data(), expected_digest.size()),
               Bytes(digest_buf, digest_size));
     OPENSSL_cleanse(digest_buf, sizeof(digest_buf));
diff --git a/crypto/x509/v3_lib.c b/crypto/x509/v3_lib.c
index 6b12975761..322a210af5 100644
--- a/crypto/x509/v3_lib.c
+++ b/crypto/x509/v3_lib.c
@@ -150,7 +150,7 @@ const X509V3_EXT_METHOD *X509V3_EXT_get_nid(int nid) {
 
 const X509V3_EXT_METHOD *X509V3_EXT_get(const X509_EXTENSION *ext) {
   int nid;
-  if ((nid = OBJ_obj2nid(ext->object)) == NID_undef) {
+  if (ext == NULL || (nid = OBJ_obj2nid(ext->object)) == NID_undef) {
     return NULL;
   }
   return X509V3_EXT_get_nid(nid);