From b6e03cc59208305681745ad06f2056ffe6690597 Mon Sep 17 00:00:00 2001 From: Pieter Wuille Date: Sun, 12 Oct 2014 18:39:47 -0700 Subject: Add SCRIPT_VERIFY_CLEANSTACK (BIP62 rule 6) Based on an earlier patch by Peter Todd, though the rules here are different (P2SH scripts should not have a CLEANSTACK check before the P2SH evaluation). --- src/script/interpreter.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'src/script/interpreter.h') diff --git a/src/script/interpreter.h b/src/script/interpreter.h index 35b2f6c65a..9b35b176ae 100644 --- a/src/script/interpreter.h +++ b/src/script/interpreter.h @@ -67,8 +67,14 @@ enum // discouraged NOPs fails the script. This verification flag will never be // a mandatory flag applied to scripts in a block. NOPs that are not // executed, e.g. within an unexecuted IF ENDIF block, are *not* rejected. - SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS = (1U << 7) - + SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS = (1U << 7), + + // Require that only a single stack element remains after evaluation. This changes the success criterion from + // "At least one stack element must remain, and when interpreted as a boolean, it must be true" to + // "Exactly one stack element must remain, and when interpreted as a boolean, it must be true". + // (softfork safe, BIP62 rule 6) + // Note: CLEANSTACK should never be used without P2SH. + SCRIPT_VERIFY_CLEANSTACK = (1U << 8), }; uint256 SignatureHash(const CScript &scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType); -- cgit v1.2.3