diff --git a/src/simplewallet/simplewallet.cpp b/src/simplewallet/simplewallet.cpp
index 41665e4d..b466251a 100644
--- a/src/simplewallet/simplewallet.cpp
+++ b/src/simplewallet/simplewallet.cpp
@@ -997,7 +997,7 @@ bool simple_wallet::init(const boost::program_options::variables_map& vm)
         return false;
       }
       cryptonote::blobdata viewkey_data;
-      if(!epee::string_tools::parse_hexstr_to_binbuff(viewkey_string, viewkey_data))
+      if(!epee::string_tools::parse_hexstr_to_binbuff(viewkey_string, viewkey_data) || viewkey_data.size() != sizeof(crypto::secret_key))
       {
         fail_msg_writer() << tr("failed to parse view key secret key");
         return false;
@@ -1049,7 +1049,7 @@ bool simple_wallet::init(const boost::program_options::variables_map& vm)
         return false;
       }
       cryptonote::blobdata spendkey_data;
-      if(!epee::string_tools::parse_hexstr_to_binbuff(spendkey_string, spendkey_data))
+      if(!epee::string_tools::parse_hexstr_to_binbuff(spendkey_string, spendkey_data) || spendkey_data.size() != sizeof(crypto::secret_key))
       {
         fail_msg_writer() << tr("failed to parse spend key secret key");
         return false;
@@ -1065,7 +1065,7 @@ bool simple_wallet::init(const boost::program_options::variables_map& vm)
         return false;
       }
       cryptonote::blobdata viewkey_data;
-      if(!epee::string_tools::parse_hexstr_to_binbuff(viewkey_string, viewkey_data))
+      if(!epee::string_tools::parse_hexstr_to_binbuff(viewkey_string, viewkey_data) || viewkey_data.size() != sizeof(crypto::secret_key))
       {
         fail_msg_writer() << tr("failed to parse view key secret key");
         return false;
@@ -3166,7 +3166,7 @@ bool simple_wallet::get_tx_key(const std::vector<std::string> &args_)
   if (m_wallet->ask_password() && !get_and_verify_password()) { return true; }
 
   cryptonote::blobdata txid_data;
-  if(!epee::string_tools::parse_hexstr_to_binbuff(local_args.front(), txid_data))
+  if(!epee::string_tools::parse_hexstr_to_binbuff(local_args.front(), txid_data) || txid_data.size() != sizeof(crypto::hash))
   {
     fail_msg_writer() << tr("failed to parse txid");
     return false;
@@ -3203,7 +3203,7 @@ bool simple_wallet::check_tx_key(const std::vector<std::string> &args_)
 
   assert(m_wallet);
   cryptonote::blobdata txid_data;
-  if(!epee::string_tools::parse_hexstr_to_binbuff(local_args[0], txid_data))
+  if(!epee::string_tools::parse_hexstr_to_binbuff(local_args[0], txid_data) || txid_data.size() != sizeof(crypto::hash))
   {
     fail_msg_writer() << tr("failed to parse txid");
     return true;
@@ -3219,7 +3219,7 @@ bool simple_wallet::check_tx_key(const std::vector<std::string> &args_)
   }
   crypto::secret_key tx_key;
   cryptonote::blobdata tx_key_data;
-  if(!epee::string_tools::parse_hexstr_to_binbuff(local_args[1], tx_key_data))
+  if(!epee::string_tools::parse_hexstr_to_binbuff(local_args[1], tx_key_data) || tx_key_data.size() != sizeof(crypto::secret_key))
   {
     fail_msg_writer() << tr("failed to parse tx key");
     return true;
@@ -3851,7 +3851,7 @@ bool simple_wallet::set_tx_note(const std::vector<std::string> &args)
   }
 
   cryptonote::blobdata txid_data;
-  if(!epee::string_tools::parse_hexstr_to_binbuff(args.front(), txid_data))
+  if(!epee::string_tools::parse_hexstr_to_binbuff(args.front(), txid_data) || txid_data.size() != sizeof(crypto::hash))
   {
     fail_msg_writer() << tr("failed to parse txid");
     return false;
@@ -3879,7 +3879,7 @@ bool simple_wallet::get_tx_note(const std::vector<std::string> &args)
   }
 
   cryptonote::blobdata txid_data;
-  if(!epee::string_tools::parse_hexstr_to_binbuff(args.front(), txid_data))
+  if(!epee::string_tools::parse_hexstr_to_binbuff(args.front(), txid_data) || txid_data.size() != sizeof(crypto::hash))
   {
     fail_msg_writer() << tr("failed to parse txid");
     return false;
@@ -4179,7 +4179,7 @@ bool simple_wallet::show_transfer(const std::vector<std::string> &args)
   }
 
   cryptonote::blobdata txid_data;
-  if(!epee::string_tools::parse_hexstr_to_binbuff(args.front(), txid_data))
+  if(!epee::string_tools::parse_hexstr_to_binbuff(args.front(), txid_data) || txid_data.size() != sizeof(crypto::hash))
   {
     fail_msg_writer() << tr("failed to parse txid");
     return false;
diff --git a/src/wallet/api/wallet.cpp b/src/wallet/api/wallet.cpp
index c46de6b0..326ca26a 100644
--- a/src/wallet/api/wallet.cpp
+++ b/src/wallet/api/wallet.cpp
@@ -1157,7 +1157,7 @@ void WalletImpl::setDefaultMixin(uint32_t arg)
 bool WalletImpl::setUserNote(const std::string &txid, const std::string &note)
 {
     cryptonote::blobdata txid_data;
-    if(!epee::string_tools::parse_hexstr_to_binbuff(txid, txid_data))
+    if(!epee::string_tools::parse_hexstr_to_binbuff(txid, txid_data) || txid_data.size() != sizeof(crypto::hash))
       return false;
     const crypto::hash htxid = *reinterpret_cast<const crypto::hash*>(txid_data.data());
 
@@ -1168,7 +1168,7 @@ bool WalletImpl::setUserNote(const std::string &txid, const std::string &note)
 std::string WalletImpl::getUserNote(const std::string &txid) const
 {
     cryptonote::blobdata txid_data;
-    if(!epee::string_tools::parse_hexstr_to_binbuff(txid, txid_data))
+    if(!epee::string_tools::parse_hexstr_to_binbuff(txid, txid_data) || txid_data.size() != sizeof(crypto::hash))
       return "";
     const crypto::hash htxid = *reinterpret_cast<const crypto::hash*>(txid_data.data());
 
@@ -1178,7 +1178,7 @@ std::string WalletImpl::getUserNote(const std::string &txid) const
 std::string WalletImpl::getTxKey(const std::string &txid) const
 {
     cryptonote::blobdata txid_data;
-    if(!epee::string_tools::parse_hexstr_to_binbuff(txid, txid_data))
+    if(!epee::string_tools::parse_hexstr_to_binbuff(txid, txid_data) || txid_data.size() != sizeof(crypto::hash))
     {
       return "";
     }
diff --git a/src/wallet/api/wallet_manager.cpp b/src/wallet/api/wallet_manager.cpp
index 4104e788..6feec75b 100644
--- a/src/wallet/api/wallet_manager.cpp
+++ b/src/wallet/api/wallet_manager.cpp
@@ -182,7 +182,7 @@ bool WalletManagerImpl::checkPayment(const std::string &address_text, const std:
 {
   error = "";
   cryptonote::blobdata txid_data;
-  if(!epee::string_tools::parse_hexstr_to_binbuff(txid_text, txid_data))
+  if(!epee::string_tools::parse_hexstr_to_binbuff(txid_text, txid_data) || txid_data.size() != sizeof(crypto::hash))
   {
     error = tr("failed to parse txid");
     return false;
@@ -196,7 +196,7 @@ bool WalletManagerImpl::checkPayment(const std::string &address_text, const std:
   }
   crypto::secret_key tx_key;
   cryptonote::blobdata tx_key_data;
-  if(!epee::string_tools::parse_hexstr_to_binbuff(txkey_text, tx_key_data))
+  if(!epee::string_tools::parse_hexstr_to_binbuff(txkey_text, tx_key_data) || tx_key_data.size() != sizeof(crypto::hash))
   {
     error = tr("failed to parse tx key");
     return false;
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index e7a175dc..250210cb 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -251,7 +251,7 @@ std::unique_ptr<tools::wallet2> generate_from_json(const std::string& json_file,
     if (field_viewkey_found)
     {
       cryptonote::blobdata viewkey_data;
-      if(!epee::string_tools::parse_hexstr_to_binbuff(field_viewkey, viewkey_data))
+      if(!epee::string_tools::parse_hexstr_to_binbuff(field_viewkey, viewkey_data) || viewkey_data.size() != sizeof(crypto::secret_key))
       {
         tools::fail_msg_writer() << tools::wallet2::tr("failed to parse view key secret key");
         return false;
@@ -269,7 +269,7 @@ std::unique_ptr<tools::wallet2> generate_from_json(const std::string& json_file,
     if (field_spendkey_found)
     {
       cryptonote::blobdata spendkey_data;
-      if(!epee::string_tools::parse_hexstr_to_binbuff(field_spendkey, spendkey_data))
+      if(!epee::string_tools::parse_hexstr_to_binbuff(field_spendkey, spendkey_data) || spendkey_data.size() != sizeof(crypto::secret_key))
       {
         tools::fail_msg_writer() << tools::wallet2::tr("failed to parse spend key secret key");
         return false;
@@ -1456,7 +1456,7 @@ void wallet2::update_pool_state()
   for (auto it: res.transactions)
   {
     cryptonote::blobdata txid_data;
-    if(epee::string_tools::parse_hexstr_to_binbuff(it.id_hash, txid_data))
+    if(epee::string_tools::parse_hexstr_to_binbuff(it.id_hash, txid_data) && txid_data.size() == sizeof(crypto::hash))
     {
       const crypto::hash txid = *reinterpret_cast<const crypto::hash*>(txid_data.data());
       if (m_unconfirmed_payments.find(txid) == m_unconfirmed_payments.end())
diff --git a/src/wallet/wallet_rpc_server.cpp b/src/wallet/wallet_rpc_server.cpp
index 881279e4..ee50c3cd 100644
--- a/src/wallet/wallet_rpc_server.cpp
+++ b/src/wallet/wallet_rpc_server.cpp
@@ -983,7 +983,7 @@ namespace tools
     while (i != req.txids.end())
     {
       cryptonote::blobdata txid_blob;
-      if(!epee::string_tools::parse_hexstr_to_binbuff(*i++, txid_blob))
+      if(!epee::string_tools::parse_hexstr_to_binbuff(*i++, txid_blob) || txid_blob.size() != sizeof(crypto::hash))
       {
         er.code = WALLET_RPC_ERROR_CODE_WRONG_TXID;
         er.message = "TX ID has invalid format";
@@ -1013,7 +1013,7 @@ namespace tools
     while (i != req.txids.end())
     {
       cryptonote::blobdata txid_blob;
-      if(!epee::string_tools::parse_hexstr_to_binbuff(*i++, txid_blob))
+      if(!epee::string_tools::parse_hexstr_to_binbuff(*i++, txid_blob) || txid_blob.size() != sizeof(crypto::hash))
       {
         er.code = WALLET_RPC_ERROR_CODE_WRONG_TXID;
         er.message = "TX ID has invalid format";
@@ -1206,7 +1206,7 @@ namespace tools
       {
         cryptonote::blobdata bd;
 
-        if(!epee::string_tools::parse_hexstr_to_binbuff(req.signed_key_images[n].key_image, bd))
+        if(!epee::string_tools::parse_hexstr_to_binbuff(req.signed_key_images[n].key_image, bd) || bd.size() != sizeof(crypto::key_image))
         {
           er.code = WALLET_RPC_ERROR_CODE_WRONG_KEY_IMAGE;
           er.message = "failed to parse key image";
@@ -1214,7 +1214,7 @@ namespace tools
         }
         ski[n].first = *reinterpret_cast<const crypto::key_image*>(bd.data());
 
-        if(!epee::string_tools::parse_hexstr_to_binbuff(req.signed_key_images[n].signature, bd))
+        if(!epee::string_tools::parse_hexstr_to_binbuff(req.signed_key_images[n].signature, bd) || bd.size() != sizeof(crypto::signature))
         {
           er.code = WALLET_RPC_ERROR_CODE_WRONG_SIGNATURE;
           er.message = "failed to parse signature";