From e36f5b6021eb541d72fee4b2d5643ba42fd4d9dd Mon Sep 17 00:00:00 2001
From: moneromooo-monero <moneromooo-monero@users.noreply.github.com>
Date: Sat, 4 Nov 2017 10:39:17 +0000
Subject: Match surae's recommendation to derive multisig keys

---
 src/wallet/wallet2.cpp | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

(limited to 'src/wallet/wallet2.cpp')

diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index 013ad6a75..29ca3dd2f 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -2830,8 +2830,6 @@ std::string wallet2::make_multisig(const epee::wipeable_string &password,
     // We need an extra step, so we package all the composite public keys
     // we know about, and make a signed string out of them
     std::string data;
-    const crypto::public_key &pkey = get_account().get_keys().m_account_address.m_spend_public_key;
-    data += std::string((const char *)&pkey, sizeof(crypto::public_key));
     const crypto::public_key signer = get_multisig_signer_public_key(rct::rct2sk(spend_skey));
     data += std::string((const char *)&signer, sizeof(crypto::public_key));
 
@@ -2844,7 +2842,7 @@ std::string wallet2::make_multisig(const epee::wipeable_string &password,
     data.resize(data.size() + sizeof(crypto::signature));
     crypto::cn_fast_hash(data.data(), data.size() - sizeof(signature), hash);
     crypto::signature &signature = *(crypto::signature*)&data[data.size() - sizeof(crypto::signature)];
-    crypto::generate_signature(hash, pkey, get_account().get_keys().m_spend_secret_key, signature);
+    crypto::generate_signature(hash, signer, get_multisig_blinded_secret_key(rct::rct2sk(spend_skey)), signature);
 
     extra_multisig_info = std::string("MultisigxV1") + tools::base58::encode(data);
   }
@@ -2958,19 +2956,18 @@ bool wallet2::finalize_multisig(const epee::wipeable_string &password, const std
 std::string wallet2::get_multisig_info() const
 {
   // It's a signed package of private view key and public spend key
-  const crypto::secret_key &skey = get_account().get_keys().m_view_secret_key;
-  const crypto::public_key &pkey = get_account().get_keys().m_account_address.m_spend_public_key;
+  const crypto::secret_key skey = cryptonote::get_multisig_blinded_secret_key(get_account().get_keys().m_view_secret_key);
+  const crypto::public_key pkey = get_multisig_signer_public_key(get_account().get_keys().m_spend_secret_key);
   crypto::hash hash;
 
   std::string data;
-  crypto::cn_fast_hash(&skey, sizeof(crypto::secret_key), hash);
-  data += std::string((const char *)&hash, sizeof(crypto::hash));
+  data += std::string((const char *)&skey, sizeof(crypto::secret_key));
   data += std::string((const char *)&pkey, sizeof(crypto::public_key));
 
   data.resize(data.size() + sizeof(crypto::signature));
   crypto::cn_fast_hash(data.data(), data.size() - sizeof(signature), hash);
   crypto::signature &signature = *(crypto::signature*)&data[data.size() - sizeof(crypto::signature)];
-  crypto::generate_signature(hash, pkey, get_account().get_keys().m_spend_secret_key, signature);
+  crypto::generate_signature(hash, pkey, get_multisig_blinded_secret_key(get_account().get_keys().m_spend_secret_key), signature);
 
   return std::string("MultisigV1") + tools::base58::encode(data);
 }
@@ -3027,28 +3024,26 @@ bool wallet2::verify_extra_multisig_info(const std::string &data, std::unordered
     MERROR("Multisig info decoding error");
     return false;
   }
-  if (decoded.size() < sizeof(crypto::public_key) + sizeof(crypto::public_key) + sizeof(crypto::signature))
+  if (decoded.size() < sizeof(crypto::public_key) + sizeof(crypto::signature))
   {
     MERROR("Multisig info is corrupt");
     return false;
   }
-  if ((decoded.size() - (sizeof(crypto::public_key) + sizeof(crypto::public_key) + sizeof(crypto::signature))) % sizeof(crypto::public_key))
+  if ((decoded.size() - (sizeof(crypto::public_key) + sizeof(crypto::signature))) % sizeof(crypto::public_key))
   {
     MERROR("Multisig info is corrupt");
     return false;
   }
 
-  const size_t n_keys = (decoded.size() - (sizeof(crypto::public_key) + sizeof(crypto::public_key) + sizeof(crypto::signature))) / sizeof(crypto::public_key);
+  const size_t n_keys = (decoded.size() - (sizeof(crypto::public_key) + sizeof(crypto::signature))) / sizeof(crypto::public_key);
   size_t offset = 0;
-  const crypto::public_key &pkey = *(const crypto::public_key*)(decoded.data() + offset);
-  offset += sizeof(pkey);
   signer = *(const crypto::public_key*)(decoded.data() + offset);
   offset += sizeof(signer);
   const crypto::signature &signature = *(const crypto::signature*)(decoded.data() + offset + n_keys * sizeof(crypto::public_key));
 
   crypto::hash hash;
   crypto::cn_fast_hash(decoded.data(), decoded.size() - sizeof(signature), hash);
-  if (!crypto::check_signature(hash, pkey, signature))
+  if (!crypto::check_signature(hash, signer, signature))
   {
     MERROR("Multisig info signature is invalid");
     return false;
@@ -8313,13 +8308,19 @@ size_t wallet2::import_outputs(const std::vector<tools::wallet2::transfer_detail
 crypto::public_key wallet2::get_multisig_signer_public_key(const crypto::secret_key &spend_skey) const
 {
   crypto::public_key pkey;
-  crypto::secret_key_to_public_key(spend_skey, pkey);
+  crypto::secret_key_to_public_key(get_multisig_blinded_secret_key(spend_skey), pkey);
   return pkey;
 }
 //----------------------------------------------------------------------------------------------------
 crypto::public_key wallet2::get_multisig_signer_public_key() const
 {
   CHECK_AND_ASSERT_THROW_MES(m_multisig, "Wallet is not multisig");
+  if (m_multisig_threshold == m_multisig_signers.size())
+  {
+    crypto::public_key signer;
+    CHECK_AND_ASSERT_THROW_MES(crypto::secret_key_to_public_key(get_account().get_keys().m_spend_secret_key, signer), "Failed to generate signer public key");
+    return signer;
+  }
   return get_multisig_signer_public_key(get_account().get_keys().m_spend_secret_key);
 }
 //----------------------------------------------------------------------------------------------------
-- 
cgit v1.2.3