Mark some local symbols as static

This isn't sufficient to fix symbol prefixing with the libcrypto C++
move, but fixes the more egregious instances. And, C or C++, those
should have been file-local.

Change-Id: I333b87488499a15d0a9002f240aa985593be6139
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/73767
Auto-Submit: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>

crypto/md4/md4.cc

diff --git a/crypto/md4/md4.cc b/crypto/md4/md4.cc
index 8090021..96697b8 100644
--- a/crypto/md4/md4.cc
+++ b/crypto/md4/md4.cc
@@ -83,7 +83,8 @@
   return 1;
 }
 
-void md4_block_data_order(uint32_t *state, const uint8_t *data, size_t num);
+static void md4_block_data_order(uint32_t *state, const uint8_t *data,
+                                 size_t num);
 
 void MD4_Transform(MD4_CTX *c, const uint8_t data[MD4_CBLOCK]) {
   md4_block_data_order(c->h, data, 1);
@@ -132,7 +133,8 @@
     (a) = CRYPTO_rotl_u32(a, s);           \
   } while (0)
 
-void md4_block_data_order(uint32_t *state, const uint8_t *data, size_t num) {
+static void md4_block_data_order(uint32_t *state, const uint8_t *data,
+                                 size_t num) {
   uint32_t A, B, C, D;
   uint32_t X0, X1, X2, X3, X4, X5, X6, X7, X8, X9, X10, X11, X12, X13, X14, X15;
 

crypto/mlkem/mlkem.cc

diff --git a/crypto/mlkem/mlkem.cc b/crypto/mlkem/mlkem.cc
index a79ccf7..18ebb43 100644
--- a/crypto/mlkem/mlkem.cc
+++ b/crypto/mlkem/mlkem.cc
@@ -75,11 +75,11 @@
 static const int kDU1024 = 11;
 static const int kDV1024 = 5;
 
-constexpr size_t encoded_vector_size(int rank) {
+static constexpr size_t encoded_vector_size(int rank) {
   return (kLog2Prime * DEGREE / 8) * static_cast<size_t>(rank);
 }
 
-constexpr size_t encoded_public_key_size(int rank) {
+static constexpr size_t encoded_public_key_size(int rank) {
   return encoded_vector_size(rank) + /*sizeof(rho)=*/32;
 }
 
@@ -88,13 +88,13 @@
 static_assert(encoded_public_key_size(RANK1024) == MLKEM1024_PUBLIC_KEY_BYTES,
               "");
 
-constexpr size_t compressed_vector_size(int rank) {
+static constexpr size_t compressed_vector_size(int rank) {
   // `if constexpr` isn't available in C++17.
   return (rank == RANK768 ? kDU768 : kDU1024) * static_cast<size_t>(rank) *
          DEGREE / 8;
 }
 
-constexpr size_t ciphertext_size(int rank) {
+static constexpr size_t ciphertext_size(int rank) {
   return compressed_vector_size(rank) +
          (rank == RANK768 ? kDV768 : kDV1024) * DEGREE / 8;
 }
@@ -743,9 +743,9 @@
 }
 
 template <int RANK>
-void mlkem_generate_key_external_seed(uint8_t *out_encoded_public_key,
-                                      private_key<RANK> *priv,
-                                      const uint8_t seed[MLKEM_SEED_BYTES]) {
+static void mlkem_generate_key_external_seed(
+    uint8_t *out_encoded_public_key, private_key<RANK> *priv,
+    const uint8_t seed[MLKEM_SEED_BYTES]) {
   uint8_t augmented_seed[33];
   OPENSSL_memcpy(augmented_seed, seed, 32);
   augmented_seed[32] = RANK;