Merge pull request #4268

1f2409e Do memwipe for critical secret keys copied to rct::key (stoffu)

4 files changed, 15 insertions, 3 deletions

diff --git a/src/cryptonote_core/cryptonote_tx_utils.cpp b/src/cryptonote_core/cryptonote_tx_utils.cpp
index 071ce591e..1581f3088 100644
--- a/src/cryptonote_core/cryptonote_tx_utils.cpp
+++ b/src/cryptonote_core/cryptonote_tx_utils.cpp
@@ -516,6 +516,7 @@ namespace cryptonote
 
       uint64_t amount_in = 0, amount_out = 0;
       rct::ctkeyV inSk;
+      inSk.reserve(sources.size());
       // mixRing indexing is done the other way round for simple
       rct::ctkeyM mixRing(use_simple_rct ? sources.size() : n_total_outs);
       rct::keyV destinations;
@@ -532,6 +533,7 @@ namespace cryptonote
         ctkey.dest = rct::sk2rct(in_contexts[i].in_ephemeral.sec);
         ctkey.mask = sources[i].mask;
         inSk.push_back(ctkey);
+        memwipe(&ctkey, sizeof(rct::ctkey));
         // inPk: (public key, commitment)
         // will be done when filling in mixRing
         if (msout)
@@ -590,6 +592,7 @@ namespace cryptonote
         tx.rct_signatures = rct::genRctSimple(rct::hash2rct(tx_prefix_hash), inSk, destinations, inamounts, outamounts, amount_in - amount_out, mixRing, amount_keys, msout ? &kLRki : NULL, msout, index, outSk, bulletproof, hwdev);
       else
         tx.rct_signatures = rct::genRct(rct::hash2rct(tx_prefix_hash), inSk, destinations, outamounts, mixRing, amount_keys, msout ? &kLRki[0] : NULL, msout, sources[0].real_output, outSk, bulletproof, hwdev); // same index assumption
+      memwipe(inSk.data(), inSk.size() * sizeof(rct::ctkey));
 
       CHECK_AND_ASSERT_MES(tx.vout.size() == outSk.size(), false, "outSk size does not match vout");
 
diff --git a/src/multisig/multisig.cpp b/src/multisig/multisig.cpp
index d85c47772..a0a788b7d 100644
--- a/src/multisig/multisig.cpp
+++ b/src/multisig/multisig.cpp
@@ -47,9 +47,12 @@ namespace cryptonote
   crypto::secret_key get_multisig_blinded_secret_key(const crypto::secret_key &key)
   {
     rct::keyV data;
+    data.reserve(2);
     data.push_back(rct::sk2rct(key));
     data.push_back(multisig_salt);
-    return rct::rct2sk(rct::hash_to_scalar(data));
+    crypto::secret_key result = rct::rct2sk(rct::hash_to_scalar(data));
+    memwipe(&data[0], sizeof(rct::key));
+    return result;
   }
   //-----------------------------------------------------------------
   void generate_multisig_N_N(const account_keys &keys, const std::vector<crypto::public_key> &spend_keys, std::vector<crypto::secret_key> &multisig_keys, rct::key &spend_skey, rct::key &spend_pkey)
diff --git a/src/ringct/rctSigs.cpp b/src/ringct/rctSigs.cpp
index f74216ed4..cc966c44b 100644
--- a/src/ringct/rctSigs.cpp
+++ b/src/ringct/rctSigs.cpp
@@ -492,7 +492,9 @@ namespace rct {
         for (size_t j = 0; j < outPk.size(); j++) {
             sc_sub(sk[rows].bytes, sk[rows].bytes, outSk[j].mask.bytes); //subtract output masks in last row..
         }
-        return MLSAG_Gen(message, M, sk, kLRki, mscout, index, rows, hwdev);
+        mgSig result = MLSAG_Gen(message, M, sk, kLRki, mscout, index, rows, hwdev);
+        memwipe(sk.data(), sk.size() * sizeof(key));
+        return result;
     }
 
 
@@ -521,7 +523,9 @@ namespace rct {
             M[i][0] = pubs[i].dest;
             subKeys(M[i][1], pubs[i].mask, Cout);
         }
-        return MLSAG_Gen(message, M, sk, kLRki, mscout, index, rows, hwdev);
+        mgSig result = MLSAG_Gen(message, M, sk, kLRki, mscout, index, rows, hwdev);
+        memwipe(&sk[0], sizeof(key));
+        return result;
     }
 
 
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index e14c1f501..bd86ae075 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -3388,6 +3388,7 @@ void wallet2::generate(const std::string& wallet_, const epee::wipeable_string&
   for (const auto &msk: multisig_keys)
     sc_add(skey.bytes, skey.bytes, rct::sk2rct(msk).bytes);
   THROW_WALLET_EXCEPTION_IF(!(rct::rct2sk(skey) == spend_secret_key), error::invalid_multisig_seed);
+  memwipe(&skey, sizeof(rct::key));
 
   m_account.make_multisig(view_secret_key, spend_secret_key, spend_public_key, multisig_keys);
   m_account.finalize_multisig(spend_public_key);
@@ -3750,6 +3751,7 @@ std::string wallet2::make_multisig(const epee::wipeable_string &password,
   MINFO("Creating multisig address...");
   CHECK_AND_ASSERT_THROW_MES(m_account.make_multisig(view_skey, rct::rct2sk(spend_skey), rct::rct2pk(spend_pkey), multisig_keys),
       "Failed to create multisig wallet due to bad keys");
+  memwipe(&spend_skey, sizeof(rct::key));
 
   m_account_public_address = m_account.get_keys().m_account_address;
   m_watch_only = false;