From 921dd8dde5d381052d0aa2936304a3541a230c55 Mon Sep 17 00:00:00 2001 From: Sarang Noether <32460187+SarangNoether@users.noreply.github.com> Date: Sun, 9 Aug 2020 19:11:54 -0400 Subject: Use domain-separated ChaCha20 for in-memory key encryption --- src/cryptonote_basic/account.cpp | 102 +++++++++++++++++++++++---------------- src/cryptonote_basic/account.h | 19 ++++---- 2 files changed, 71 insertions(+), 50 deletions(-) (limited to 'src/cryptonote_basic') diff --git a/src/cryptonote_basic/account.cpp b/src/cryptonote_basic/account.cpp index 36ff41684..b366985ab 100644 --- a/src/cryptonote_basic/account.cpp +++ b/src/cryptonote_basic/account.cpp @@ -61,7 +61,8 @@ DISABLE_VS_WARNINGS(4244 4345) m_device = &hwdev; MCDEBUG("device", "account_keys::set_device device type: "<(); - // chacha - epee::wipeable_string buffer0(std::string(bytes, '\0')); - epee::wipeable_string buffer1 = buffer0; - crypto::chacha20(buffer0.data(), buffer0.size(), key, iv, buffer1.data()); - return buffer1; + // Now do the chacha + chacha_wrapper(key, all_keys); } - //----------------------------------------------------------------- - void account_keys::xor_with_key_stream(const crypto::chacha_key &key) + + // Start chacha for decryption + void account_keys::decrypt_wrapper(const crypto::chacha_key &key, const bool all_keys) + { + chacha_wrapper(key, all_keys); + } + + // Decrypt keys using the legacy method + void account_keys::decrypt_legacy(const crypto::chacha_key &key) { - // encrypt a large enough byte stream with chacha20 - epee::wipeable_string key_stream = get_key_stream(key, m_encryption_iv, sizeof(crypto::secret_key) * (2 + m_multisig_keys.size())); - const char *ptr = key_stream.data(); + // Derive domain-separated chacha key + crypto::chacha_key derived_key; + derive_key(key, derived_key); + + // Build key stream + epee::wipeable_string temp(std::string(sizeof(crypto::secret_key)*(2 + m_multisig_keys.size()), '\0')); + epee::wipeable_string stream = temp; + crypto::chacha20(temp.data(), temp.size(), derived_key, m_encryption_iv, stream.data()); + + // Decrypt all keys + const char *ptr = stream.data(); for (size_t i = 0; i < sizeof(crypto::secret_key); ++i) m_spend_secret_key.data[i] ^= *ptr++; for (size_t i = 0; i < sizeof(crypto::secret_key); ++i) @@ -99,33 +113,39 @@ DISABLE_VS_WARNINGS(4244 4345) k.data[i] ^= *ptr++; } } - //----------------------------------------------------------------- - void account_keys::encrypt(const crypto::chacha_key &key) + + // Perform chacha on either the view key or all keys + void account_keys::chacha_wrapper(const crypto::chacha_key &key, const bool all_keys) { - m_encryption_iv = crypto::rand(); - xor_with_key_stream(key); - } - //----------------------------------------------------------------- - void account_keys::decrypt(const crypto::chacha_key &key) - { - xor_with_key_stream(key); - } - //----------------------------------------------------------------- - void account_keys::encrypt_viewkey(const crypto::chacha_key &key) - { - // encrypt a large enough byte stream with chacha20 - epee::wipeable_string key_stream = get_key_stream(key, m_encryption_iv, sizeof(crypto::secret_key) * 2); - const char *ptr = key_stream.data(); - ptr += sizeof(crypto::secret_key); - for (size_t i = 0; i < sizeof(crypto::secret_key); ++i) - m_view_secret_key.data[i] ^= *ptr++; - } - //----------------------------------------------------------------- - void account_keys::decrypt_viewkey(const crypto::chacha_key &key) - { - encrypt_viewkey(key); + // Derive domain-seprated chacha key + crypto::chacha_key derived_key; + derive_key(key, derived_key); + + // Chacha the specified keys using the appropriate IVs + if (all_keys) + { + // Spend key + crypto::secret_key temp_key; + chacha20((char *) &m_spend_secret_key, sizeof(crypto::secret_key), derived_key, m_encryption_iv, (char *) &temp_key); + memcpy(&m_spend_secret_key, &temp_key, sizeof(crypto::secret_key)); + memwipe(&temp_key, sizeof(crypto::secret_key)); + + // Multisig keys + std::vector temp_keys; + temp_keys.reserve(m_multisig_keys.size()); + temp_keys.resize(m_multisig_keys.size()); + chacha20((char *) &m_multisig_keys[0], sizeof(crypto::secret_key)*m_multisig_keys.size(), derived_key, m_encryption_iv, (char *) &temp_keys[0]); + memcpy(&m_multisig_keys[0], &temp_keys[0], sizeof(crypto::secret_key)*temp_keys.size()); + memwipe(&temp_keys[0], sizeof(crypto::secret_key)*temp_keys.size()); + } + + // View key + crypto::secret_key temp_key; + chacha20((char *) &m_view_secret_key, sizeof(crypto::secret_key), derived_key, m_encryption_iv, (char *) &temp_key); + memcpy(&m_view_secret_key, &temp_key, sizeof(crypto::secret_key)); + memwipe(&temp_key, sizeof(crypto::secret_key)); } - //----------------------------------------------------------------- + account_base::account_base() { set_null(); diff --git a/src/cryptonote_basic/account.h b/src/cryptonote_basic/account.h index 5288b9b04..c71c06edd 100644 --- a/src/cryptonote_basic/account.h +++ b/src/cryptonote_basic/account.h @@ -57,16 +57,15 @@ namespace cryptonote account_keys& operator=(account_keys const&) = default; - void encrypt(const crypto::chacha_key &key); - void decrypt(const crypto::chacha_key &key); - void encrypt_viewkey(const crypto::chacha_key &key); - void decrypt_viewkey(const crypto::chacha_key &key); + void encrypt_wrapper(const crypto::chacha_key &key, const bool all_keys); + void decrypt_wrapper(const crypto::chacha_key &key, const bool all_keys); + void decrypt_legacy(const crypto::chacha_key &key); hw::device& get_device() const ; void set_device( hw::device &hwdev) ; private: - void xor_with_key_stream(const crypto::chacha_key &key); + void chacha_wrapper(const crypto::chacha_key &key, const bool all_keys); }; /************************************************************************/ @@ -100,10 +99,12 @@ namespace cryptonote void forget_spend_key(); const std::vector &get_multisig_keys() const { return m_keys.m_multisig_keys; } - void encrypt_keys(const crypto::chacha_key &key) { m_keys.encrypt(key); } - void decrypt_keys(const crypto::chacha_key &key) { m_keys.decrypt(key); } - void encrypt_viewkey(const crypto::chacha_key &key) { m_keys.encrypt_viewkey(key); } - void decrypt_viewkey(const crypto::chacha_key &key) { m_keys.decrypt_viewkey(key); } + void encrypt_keys(const crypto::chacha_key &key) { m_keys.encrypt_wrapper(key, true); } + void encrypt_keys_same_iv(const crypto::chacha_key &key) { m_keys.decrypt_wrapper(key, true); } // encryption with the same IV is the same as decryption due to symmetry + void decrypt_keys(const crypto::chacha_key &key) { m_keys.decrypt_wrapper(key, true); } + void encrypt_viewkey(const crypto::chacha_key &key) { m_keys.encrypt_wrapper(key, false); } + void decrypt_viewkey(const crypto::chacha_key &key) { m_keys.decrypt_wrapper(key, false); } + void decrypt_legacy(const crypto::chacha_key &key) { m_keys.decrypt_legacy(key); } template inline void serialize(t_archive &a, const unsigned int /*ver*/) -- cgit v1.2.3