OP_CHECKBLOCKATHEIGHT anti-replay (BIP 115; logic only) #10391

pull luke-jr wants to merge 5 commits into bitcoin:master from luke-jr:cbah changing 21 files +210 −77

luke-jr commented at 4:15 AM on May 12, 2017: member

No description provided.
script: Allow interpreter to fail with SCRIPT_ERR_NOT_FINAL to indicate a context-dependent/non-final status b779f5a12a
policy: Split STANDARD_SCRIPT_VERIFY_FLAGS between contextual and non-contextual 7aabfd8111
Pass CChain through to signature checker in contextual verifications 04b0a00c72
script: Implement OP_CHECKBLOCKATHEIGHT c1bf3d75ed
CHistoricalChain to fix context in CVerifyDB 316d727dda
dcousens commented at 4:22 AM on May 12, 2017: contributor

https://github.com/luke-jr/bips/blob/bip-0115/bip-0115.mediawiki - for others reference
in src/script/interpreter.cpp:443 in 316d727dda
```
 439 | +                    if (stack.size() < 2) {
 440 | +                        return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
 441 | +                    }
 442 | +
 443 | +                    // nHeight is a 32-bit signed integer field.
 444 | +                    const int32_t nHeight = CScriptNum(stacktop(-1), true, 4).getint();
```
WaveringAna commented at 2:39 AM on July 10, 2017:

Can this cause a buffer overflow if a block height over 2147483647 occurs?

luke-jr commented at 3:29 AM on July 10, 2017:

No? Why would it?

WaveringAna commented at 3:41 AM on July 10, 2017:

nHeight is a int32_t, if someone makes a transaction with 2147483648 as the referenced block, it would cause an overflow

luke-jr commented at 4:25 AM on July 10, 2017:

Not all overflows are buffer overflows. In this case, CScriptNum explicitly limits the size.
luke-jr commented at 7:05 PM on November 16, 2017: member

The BIP needs revising for static analysis compat.
luke-jr closed this on Nov 16, 2017
DrahtBot locked this on Sep 8, 2021

Contributors

luke-jr

dcousens

WaveringAna