diff options
Diffstat (limited to 'src/script/interpreter.h')
| -rw-r--r-- | src/script/interpreter.h | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/src/script/interpreter.h b/src/script/interpreter.h index 2eae68179e..83a96739b1 100644 --- a/src/script/interpreter.h +++ b/src/script/interpreter.h @@ -27,37 +27,40 @@ enum SIGHASH_ANYONECANPAY = 0x80, }; -/** Script verification flags */ +/** Script verification flags. + * + * All flags are intended to be soft forks: the set of acceptable scripts under + * flags (A | B) is a subset of the acceptable scripts under flag (A). + */ enum { SCRIPT_VERIFY_NONE = 0, - // Evaluate P2SH subscripts (softfork safe, BIP16). + // Evaluate P2SH subscripts (BIP16). SCRIPT_VERIFY_P2SH = (1U << 0), // Passing a non-strict-DER signature or one with undefined hashtype to a checksig operation causes script failure. // Evaluating a pubkey that is not (0x04 + 64 bytes) or (0x02 or 0x03 + 32 bytes) by checksig causes script failure. - // (softfork safe, but not used or intended as a consensus rule). + // (not used or intended as a consensus rule). SCRIPT_VERIFY_STRICTENC = (1U << 1), - // Passing a non-strict-DER signature to a checksig operation causes script failure (softfork safe, BIP62 rule 1) + // Passing a non-strict-DER signature to a checksig operation causes script failure (BIP62 rule 1) SCRIPT_VERIFY_DERSIG = (1U << 2), // Passing a non-strict-DER signature or one with S > order/2 to a checksig operation causes script failure - // (softfork safe, BIP62 rule 5). + // (BIP62 rule 5). SCRIPT_VERIFY_LOW_S = (1U << 3), - // verify dummy stack item consumed by CHECKMULTISIG is of zero-length (softfork safe, BIP62 rule 7). + // verify dummy stack item consumed by CHECKMULTISIG is of zero-length (BIP62 rule 7). SCRIPT_VERIFY_NULLDUMMY = (1U << 4), - // Using a non-push operator in the scriptSig causes script failure (softfork safe, BIP62 rule 2). + // Using a non-push operator in the scriptSig causes script failure (BIP62 rule 2). SCRIPT_VERIFY_SIGPUSHONLY = (1U << 5), // Require minimal encodings for all push operations (OP_0... OP_16, OP_1NEGATE where possible, direct // pushes up to 75 bytes, OP_PUSHDATA up to 255 bytes, OP_PUSHDATA2 for anything larger). Evaluating // any other push causes the script to fail (BIP62 rule 3). // In addition, whenever a stack element is interpreted as a number, it must be of minimal length (BIP62 rule 4). - // (softfork safe) SCRIPT_VERIFY_MINIMALDATA = (1U << 6), // Discourage use of NOPs reserved for upgrades (NOP1-10) @@ -68,12 +71,14 @@ 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. + // NOPs that have associated forks to give them new meaning (CLTV, CSV) + // are not subject to this rule. 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) + // (BIP62 rule 6) // Note: CLEANSTACK should never be used without P2SH or WITNESS. SCRIPT_VERIFY_CLEANSTACK = (1U << 8), |