multisig: better errors for small malformed kex msgs

Resolves https://github.com/monero-project/monero/issues/8493
This commit is contained in:
jeffro256 2023-08-08 12:01:37 -05:00
parent 00fd416a99
commit f71e2dcdc8
No known key found for this signature in database
GPG key ID: 6F79797A6E392442

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@ -206,8 +206,13 @@ namespace multisig
//----------------------------------------------------------------------------------------------------------------------
void multisig_kex_msg::parse_and_validate_msg()
{
CHECK_AND_ASSERT_THROW_MES(MULTISIG_KEX_MSG_V2_MAGIC_1.size() == MULTISIG_KEX_MSG_V2_MAGIC_N.size(),
"Multisig kex msg magic inconsistency.");
CHECK_AND_ASSERT_THROW_MES(MULTISIG_KEX_MSG_V2_MAGIC_1.size() >= MULTISIG_KEX_V1_MAGIC.size(),
"Multisig kex msg magic inconsistency.");
// check message type
CHECK_AND_ASSERT_THROW_MES(m_msg.size() > 0, "Kex message unexpectedly empty.");
CHECK_AND_ASSERT_THROW_MES(m_msg.size() >= MULTISIG_KEX_MSG_V2_MAGIC_1.size(), "Kex message unexpectedly small.");
CHECK_AND_ASSERT_THROW_MES(m_msg.substr(0, MULTISIG_KEX_V1_MAGIC.size()) != MULTISIG_KEX_V1_MAGIC,
"V1 multisig kex messages are deprecated (unsafe).");
CHECK_AND_ASSERT_THROW_MES(m_msg.substr(0, MULTISIG_KEX_MSG_V1_MAGIC.size()) != MULTISIG_KEX_MSG_V1_MAGIC,
@ -215,8 +220,6 @@ namespace multisig
// deserialize the message
std::string msg_no_magic;
CHECK_AND_ASSERT_THROW_MES(MULTISIG_KEX_MSG_V2_MAGIC_1.size() == MULTISIG_KEX_MSG_V2_MAGIC_N.size(),
"Multisig kex msg magic inconsistency.");
CHECK_AND_ASSERT_THROW_MES(tools::base58::decode(m_msg.substr(MULTISIG_KEX_MSG_V2_MAGIC_1.size()), msg_no_magic),
"Multisig kex msg decoding error.");
binary_archive<false> b_archive{epee::strspan<std::uint8_t>(msg_no_magic)};