fix: improve smsg message size validation

src/chainparamsbase.h

@@ -9,6 +9,7 @@
 
 #include <memory>
 #include <string>
+#include <cstdint>
 
 class ArgsManager;
 

src/node/interface_ui.h

@@ -9,6 +9,7 @@
 #include <functional>
 #include <memory>
 #include <string>
+#include <cstdint>
 
 class CBlockIndex;
 enum class SynchronizationState;

src/rpc/mnemonic.cpp

@@ -50,7 +50,7 @@ static RPCHelpMan mnemonicrpc()
     RPCResult{RPCResult::Type::ANY, "", ""},
     RPCExamples{
         HelpExampleCli("mnemonic", "\"new\" \"my pass phrase\" french 64 true") +
-        HelpExampleRpc("smsgpurge", "\"new\", \"my pass phrase\", french, 64, true")
+        HelpExampleRpc("mnemonic", "\"new\", \"my pass phrase\", french, 64, true")
         },
     [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
 {

src/smsg/crypter.cpp

@@ -11,7 +11,7 @@
 #include <stdint.h>
 
 
-bool SecMsgCrypter::SetKey(const std::vector<uint8_t> &vchNewKey, const uint8_t *chNewIV)
+bool SecMsgCrypter::SetKey(const std::vector<uint8_t, secure_allocator<unsigned char>> &vchNewKey, const uint8_t *chNewIV)
 {
     if (vchNewKey.size() != SMSG_CRYPTO_KEY_SIZE) {
         return false;

src/smsg/crypter.h

@@ -39,7 +39,7 @@ class SecMsgCrypter
         fKeySet = false;
     }
 
-    bool SetKey(const std::vector<uint8_t> &vchNewKey, const uint8_t *chNewIV);
+    bool SetKey(const std::vector<uint8_t, secure_allocator<unsigned char>> &vchNewKey, const uint8_t *chNewIV);
     bool SetKey(const uint8_t *chNewKey, const uint8_t *chNewIV);
     bool Encrypt(const uint8_t *chPlaintext,  uint32_t nPlain,  std::vector<uint8_t> &vchCiphertext);
     bool Decrypt(const uint8_t *chCiphertext, uint32_t nCipher, std::vector<uint8_t> &vchPlaintext);

src/smsg/rpcsmessage.cpp

@@ -2596,8 +2596,21 @@ static RPCHelpMan smsgimport()
     }
 
     std::vector<uint8_t> vsmsg = ParseHex(str_msg.c_str());
+    if (vsmsg.size() < smsg::SMSG_HDR_LEN) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "msg too short");
+    }
+
     smsg::SecureMessage smsg(vsmsg.data());
     smsg.pPayload = vsmsg.data() + smsg::SMSG_HDR_LEN;
+    if (smsg.nPayload < smsg::SMSG_MIN_CIPERTEXT_SIZE) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Smsg payload size too low");
+    }
+    if (smsg.nPayload > smsg::SMSG_MAX_MSG_WORST_PAID) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Smsg payload size too high");
+    }
+    if (smsg.nPayload != vsmsg.size() - smsg::SMSG_HDR_LEN) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Mismatched smsg payload size");
+    }
 
     UniValue result(UniValue::VOBJ);
     std::string str_error;

src/smsg/securemessage.h

@@ -44,6 +44,11 @@ class SecureMessage
         return version[0] == 3;
     }
 
+    bool IsPurged() const
+    {
+        return version[0] == 0 && version[1] == 0;
+    }
+
     void set(const uint8_t *data)
     {
         size_t ofs = 0;