dash/src/script
Wladimir J. van der Laan 90154c6074
Merge #13666: Always create signatures with Low R values
e306be742932d4ea5aca0ea4768e54b2fc3dc6a0 Use 72 byte dummy signatures when watching only inputs may be used (Andrew Chow)
48b1473c898129a99212e2db36c61cf93625ea17 Use 71 byte signature for DUMMY_SIGNATURE_CREATOR (Andrew Chow)
18dfea0dd082af18dfb02981b7ee1cd44d514388 Always create 70 byte signatures with low R values (Andrew Chow)

Pull request description:

  When creating signatures for transactions, always make one which has a 32 byte or smaller R and 32 byte or smaller S value. This results in signatures that are always less than 71 bytes (32 byte R + 32 byte S + 6 bytes DER + 1 byte sighash) with low R values. In most cases, the signature will be 71 bytes.

  Because R is not mutable in the same way that S is, a low R value can only be found by trying different nonces. RFC 6979 for deterministic nonce generation has the option to specify additional entropy, so we simply use that and add a uin32_t counter which we increment in order to try different nonces. Nonces are sill deterministically generated as the nonce used will the be the first one where the counter results in a nonce that results in a low R value. Because different nonces need to be tried, time to produce a signature does increase. On average, it takes twice as long to make a signature as two signatures need to be created, on average, to find one with a low R.

  Having a fixed size signature makes size calculations easier and also saves half a byte of transaction size, on average.

  DUMMY_SIGNATURE_CREATOR has been modified to produce 71 byte dummy signatures instead of 72 byte signatures.

Tree-SHA512: 3cd791505126ce92da7c631856a97ba0b59e87d9c132feff6e0eef1dc47768e81fbb38bfbe970371bedf9714b7f61a13a5fe9f30f962c81734092a4d19a4ef33
2021-07-06 20:29:32 +03:00
..
dashconsensus.cpp Merge #13655: bitcoinconsensus: invalid flags error should be set to bitcoinconsensus_err 2021-07-02 12:59:27 +03:00
dashconsensus.h Merge #12757: Clarify include guard naming convention 2020-07-19 00:42:54 -05:00
interpreter.cpp Merge #12460: Assert CPubKey::ValidLength to the pubkey's header-relevant size 2021-06-28 18:03:15 -05:00
interpreter.h Merge #13309: Directly operate with CMutableTransaction in SignSignature 2021-06-28 02:00:51 +03:00
ismine.cpp Merge #13491: Improve handling of INVALID in IsMine 2021-06-28 02:31:51 +03:00
ismine.h Merge #13491: Improve handling of INVALID in IsMine 2021-06-28 02:31:51 +03:00
script_error.cpp Merge #11423: [Policy] Several transaction standardness rules 2021-06-05 22:13:01 +03:00
script_error.h Merge #11423: [Policy] Several transaction standardness rules 2021-06-05 22:13:01 +03:00
script.cpp Merge #13194: Remove template matching and pseudo opcodes 2021-06-28 02:00:49 +03:00
script.h Merge #13194: Remove template matching and pseudo opcodes 2021-06-28 02:00:49 +03:00
sigcache.cpp merge bitcoin#14555: Move util files to directory 2021-06-27 12:03:13 +05:30
sigcache.h
sign.cpp Merge #13666: Always create signatures with Low R values 2021-07-06 20:29:32 +03:00
sign.h Merge #13666: Always create signatures with Low R values 2021-07-06 20:29:32 +03:00
standard.cpp Merge #13194: Remove template matching and pseudo opcodes 2021-06-28 02:00:49 +03:00
standard.h Merge #13002: Do not treat bare multisig outputs as IsMine unless watched 2021-06-05 22:13:00 +03:00