Fix msvc warning

src/lib/pubkey/classic_mceliece/cmce_field_ordering.cpp

@@ -283,7 +283,7 @@ Classic_McEliece_Field_Ordering Classic_McEliece_Field_Ordering::create_from_con
    std::iota(pi.begin(), pi.end(), 0);
    for(size_t i = 0; i < 2 * params.m() - 1; ++i) {
       size_t gap = size_t(1) << std::min(i, 2 * params.m() - 2 - i);
-      for(size_t j = 0; j < n / 2; ++j) {
+      for(size_t j = 0; j < size_t(n / 2); ++j) {
          size_t pos = (j % gap) + 2 * gap * (j / gap);
          auto mask = CT::Mask<uint16_t>::expand(control_bits[i * n / 2 + j]);
          mask.conditional_swap(pi[pos], pi[pos + gap]);
@@ -297,12 +297,12 @@ void Classic_McEliece_Field_Ordering::permute_with_pivots(const Classic_McEliece
                                                           const secure_bitvector& pivots) {
    auto col_offset = params.pk_no_rows() - Classic_McEliece_Parameters::mu();
 
-   for(uint64_t p_idx = 1; p_idx <= Classic_McEliece_Parameters::mu(); ++p_idx) {
-      uint64_t p_counter = 0;
-      for(uint64_t col = 0; col < Classic_McEliece_Parameters::nu(); ++col) {
-         auto mask_is_pivot_set = CT::Mask<uint64_t>::expand(pivots.at(col));
-         p_counter += CT::Mask<uint64_t>::expand(pivots.at(col)).if_set_return(1);
-         auto mask_is_current_pivot = CT::Mask<uint64_t>::is_equal(p_idx, p_counter);
+   for(size_t p_idx = 1; p_idx <= Classic_McEliece_Parameters::mu(); ++p_idx) {
+      size_t p_counter = 0;
+      for(size_t col = 0; col < Classic_McEliece_Parameters::nu(); ++col) {
+         auto mask_is_pivot_set = CT::Mask<size_t>::expand(pivots.at(col));
+         p_counter += CT::Mask<size_t>::expand(pivots.at(col)).if_set_return(1);
+         auto mask_is_current_pivot = CT::Mask<size_t>::is_equal(p_idx, p_counter);
          (mask_is_pivot_set & mask_is_current_pivot)
             .conditional_swap(m_pi.at(col_offset + col), m_pi.at(col_offset + p_idx - 1));
       }