crypto: replace rand<T>()%N idiom with unbiased rand_idx(N)

1 files changed, 4 insertions, 4 deletions

diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index 0e82f1a91..a4b063541 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -5719,7 +5719,7 @@ namespace
   {
     CHECK_AND_ASSERT_MES(!vec.empty(), T(), "Vector must be non-empty");
 
-    size_t idx = crypto::rand<size_t>() % vec.size();
+    size_t idx = crypto::rand_idx(vec.size());
     return pop_index (vec, idx);
   }
 
@@ -5822,7 +5822,7 @@ size_t wallet2::pop_best_value_from(const transfer_container &transfers, std::ve
   }
   else
   {
-    idx = crypto::rand<size_t>() % candidates.size();
+    idx = crypto::rand_idx(candidates.size());
   }
   return pop_index (unused_indices, candidates[idx]);
 }
@@ -7474,7 +7474,7 @@ void wallet2::get_outs(std::vector<std::vector<tools::wallet2::get_outs_entry>>
       if (n_rct == 0)
         return rct_offsets[block_offset] ? rct_offsets[block_offset] - 1 : 0;
       MDEBUG("Picking 1/" << n_rct << " in " << (last_block_offset - first_block_offset + 1) << " blocks centered around " << block_offset + rct_start_height);
-      return first_rct + crypto::rand<uint64_t>() % n_rct;
+      return first_rct + crypto::rand_idx(n_rct);
     };
 
     size_t num_selected_transfers = 0;
@@ -9603,7 +9603,7 @@ std::vector<wallet2::pending_tx> wallet2::create_transactions_all(uint64_t below
     if (unused_transfer_dust_indices_per_subaddr.count(0) == 1 && unused_transfer_dust_indices_per_subaddr.size() > 1)
       unused_transfer_dust_indices_per_subaddr.erase(0);
     auto i = unused_transfer_dust_indices_per_subaddr.begin();
-    std::advance(i, crypto::rand<size_t>() % unused_transfer_dust_indices_per_subaddr.size());
+    std::advance(i, crypto::rand_idx(unused_transfer_dust_indices_per_subaddr.size()));
     unused_transfers_indices = i->second.first;
     unused_dust_indices = i->second.second;
     LOG_PRINT_L2("Spending from subaddress index " << i->first);