Merge #8976: libconsensus: Add input validation of flags

5ca8ef2 libconsensus: Add input validation of flags (Wladimir J. van der Laan)

1 files changed, 9 insertions, 0 deletions

diff --git a/src/script/bitcoinconsensus.cpp b/src/script/bitcoinconsensus.cpp
index b629f4278b..1d0ca0c5ac 100644
--- a/src/script/bitcoinconsensus.cpp
+++ b/src/script/bitcoinconsensus.cpp
@@ -69,10 +69,19 @@ struct ECCryptoClosure
 ECCryptoClosure instance_of_eccryptoclosure;
 }
 
+/** Check that all specified flags are part of the libconsensus interface. */
+static bool verify_flags(unsigned int flags)
+{
+    return (flags & ~(bitcoinconsensus_SCRIPT_FLAGS_VERIFY_ALL)) == 0;
+}
+
 static int verify_script(const unsigned char *scriptPubKey, unsigned int scriptPubKeyLen, CAmount amount,
                                     const unsigned char *txTo        , unsigned int txToLen,
                                     unsigned int nIn, unsigned int flags, bitcoinconsensus_error* err)
 {
+    if (!verify_flags(flags)) {
+        return bitcoinconsensus_ERR_INVALID_FLAGS;
+    }
     try {
         TxInputStream stream(SER_NETWORK, PROTOCOL_VERSION, txTo, txToLen);
         CTransaction tx;