Make all script verification flags softforks

This commit is contained in:
Pieter Wuille 2017-06-28 15:49:13 -07:00
parent 2935b469ae
commit 2851b77312
3 changed files with 14 additions and 17 deletions

View File

@ -349,9 +349,6 @@ bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript&
{ {
if (!(flags & SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY)) { if (!(flags & SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY)) {
// not enabled; treat as a NOP2 // not enabled; treat as a NOP2
if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS) {
return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS);
}
break; break;
} }
@ -391,9 +388,6 @@ bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript&
{ {
if (!(flags & SCRIPT_VERIFY_CHECKSEQUENCEVERIFY)) { if (!(flags & SCRIPT_VERIFY_CHECKSEQUENCEVERIFY)) {
// not enabled; treat as a NOP3 // not enabled; treat as a NOP3
if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS) {
return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS);
}
break; break;
} }

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@ -27,37 +27,40 @@ enum
SIGHASH_ANYONECANPAY = 0x80, 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 enum
{ {
SCRIPT_VERIFY_NONE = 0, SCRIPT_VERIFY_NONE = 0,
// Evaluate P2SH subscripts (softfork safe, BIP16). // Evaluate P2SH subscripts (BIP16).
SCRIPT_VERIFY_P2SH = (1U << 0), SCRIPT_VERIFY_P2SH = (1U << 0),
// Passing a non-strict-DER signature or one with undefined hashtype to a checksig operation causes script failure. // 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. // 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), 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), SCRIPT_VERIFY_DERSIG = (1U << 2),
// Passing a non-strict-DER signature or one with S > order/2 to a checksig operation causes script failure // 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), 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), 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), SCRIPT_VERIFY_SIGPUSHONLY = (1U << 5),
// Require minimal encodings for all push operations (OP_0... OP_16, OP_1NEGATE where possible, direct // 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 // 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). // 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). // 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), SCRIPT_VERIFY_MINIMALDATA = (1U << 6),
// Discourage use of NOPs reserved for upgrades (NOP1-10) // 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 // discouraged NOPs fails the script. This verification flag will never be
// a mandatory flag applied to scripts in a block. NOPs that are not // 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. // 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), SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS = (1U << 7),
// Require that only a single stack element remains after evaluation. This changes the success criterion from // 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 // "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". // "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. // Note: CLEANSTACK should never be used without P2SH or WITNESS.
SCRIPT_VERIFY_CLEANSTACK = (1U << 8), SCRIPT_VERIFY_CLEANSTACK = (1U << 8),

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@ -862,8 +862,6 @@
["Ensure 100% coverage of discouraged NOPS"], ["Ensure 100% coverage of discouraged NOPS"],
["1", "NOP1", "P2SH,DISCOURAGE_UPGRADABLE_NOPS", "DISCOURAGE_UPGRADABLE_NOPS"], ["1", "NOP1", "P2SH,DISCOURAGE_UPGRADABLE_NOPS", "DISCOURAGE_UPGRADABLE_NOPS"],
["1", "CHECKLOCKTIMEVERIFY", "P2SH,DISCOURAGE_UPGRADABLE_NOPS", "DISCOURAGE_UPGRADABLE_NOPS"],
["1", "CHECKSEQUENCEVERIFY", "P2SH,DISCOURAGE_UPGRADABLE_NOPS", "DISCOURAGE_UPGRADABLE_NOPS"],
["1", "NOP4", "P2SH,DISCOURAGE_UPGRADABLE_NOPS", "DISCOURAGE_UPGRADABLE_NOPS"], ["1", "NOP4", "P2SH,DISCOURAGE_UPGRADABLE_NOPS", "DISCOURAGE_UPGRADABLE_NOPS"],
["1", "NOP5", "P2SH,DISCOURAGE_UPGRADABLE_NOPS", "DISCOURAGE_UPGRADABLE_NOPS"], ["1", "NOP5", "P2SH,DISCOURAGE_UPGRADABLE_NOPS", "DISCOURAGE_UPGRADABLE_NOPS"],
["1", "NOP6", "P2SH,DISCOURAGE_UPGRADABLE_NOPS", "DISCOURAGE_UPGRADABLE_NOPS"], ["1", "NOP6", "P2SH,DISCOURAGE_UPGRADABLE_NOPS", "DISCOURAGE_UPGRADABLE_NOPS"],