c020cbaa5c8e9e61b2b8efd8dc09be743fcd4273 Squashed 'src/secp256k1/' changes from efad3506a8..be8d9c262f (Pieter Wuille)
Pull request description:
This updates our src/secp256k1 subtree to the lastest upstream master. Notable changes:
* New schnorrsig API (https://github.com/bitcoin-core/secp256k1/pull/844), which adds support for variable-length messages (not used in BIP341/342 transaction signing, so not relevant for us, but it changes the API, and makes some other simplifications). Some of our call sites had to be adapted.
* Don't use asm optimizations for `gen_context` (https://github.com/bitcoin-core/secp256k1/pull/965). This fixes#22441.
* Various testing/CI improvements
ACKs for top commit:
hebasto:
ACK e4ffb44716bb7a7b9f0a5d70ac07058632234370
jonatack:
Light ACK e4ffb44716bb7a7b9f0a5d70ac07058632234370 debug built (debian clang 13.0), ran bitcoind node/tests/git-subtree-check.sh, lightly reviewed the diff and API changes
fanquake:
ACK e4ffb44716bb7a7b9f0a5d70ac07058632234370
Tree-SHA512: 89a5c3019ec010d578e84bcef756d2c679420c5c768bcdece673405c4e10955179c5a1339aafc68b8b74b1e3912e147bf2f392f44f15af73791d93f6537960b3
5c7ee1b2da6bf783d27034fca9dfd3a64ed525cb libsecp256k1 no longer has --with-bignum= configure option (Pieter Wuille)
bdca9bcb6c9379707d09c63f02326884befbefb2 Squashed 'src/secp256k1/' changes from 3967d96bf1..efad3506a8 (Pieter Wuille)
cabb5661234f8d832dbc3b65bf80b0acc02db0a0 Disable certain false positive warnings for libsecp256k1 msvc build (Pieter Wuille)
Pull request description:
This updates our src/secp256k1 subtree to the latest upstream master. The changes include:
* The introduction of safegcd-based modular inverses, reducing ECDSA signing time by 25%-30% and ECDSA verification time by 15%-17%.
* [Original paper](https://gcd.cr.yp.to/papers.html) by Daniel J. Bernstein and Bo-Yin Yang
* [Implementation](https://github.com/bitcoin-core/secp256k1/pull/767) by Peter Dettman; [final](https://github.com/bitcoin-core/secp256k1/pull/831) version
* [Explanation](https://github.com/bitcoin-core/secp256k1/blob/master/doc/safegcd_implementation.md) of the algorithm using Python snippets
* [Analysis](https://github.com/sipa/safegcd-bounds) of the maximum number of iterations the algorithm needs
* [Formal proof in Coq](https://medium.com/blockstream/a-formal-proof-of-safegcd-bounds-695e1735a348) by Russell O'Connor, for a high-level equivalent algorithm
* Removal of libgmp as an (optional) dependency (which wasn't used in the Bitcoin Core build)
* CI changes (Travis -> Cirrus)
* Build system improvements
ACKs for top commit:
laanwj:
Tested ACK 5c7ee1b2da6bf783d27034fca9dfd3a64ed525cb
Tree-SHA512: ad8ac3746264d279556a4aa7efdde3733e114fdba8856dd53218588521f04d83950366f5c1ea8fd56329b4c7fe08eedf8e206f8f26dbe3f0f81852e138655431
6c0259fc2f8bd34ba83ad10a6a11d6d99e8d1fc7 Squashed 'src/secp256k1/' changes from c6b6b8f1bb..3967d96bf1 (Pieter Wuille)
Pull request description:
Nothing important changed, but this silences this (erroneous) warning in certain GCC 9 versions:
```
In file included from src/secp256k1.c:16:
src/ecmult_impl.h: In function ‘secp256k1_ecmult’:
src/ecmult_impl.h:496:48: warning: array subscript [1, 268435456] is outside array bounds of ‘struct secp256k1_strauss_point_state[1]’ [-Warray-bounds]
496 | secp256k1_gej tmp = a[state->ps[np].input_pos];
| ~~~~~~~~~~~~~^~~~~~~~~~
src/ecmult_impl.h:565:42: note: while referencing ‘ps’
565 | struct secp256k1_strauss_point_state ps[1];
| ^~
src/ecmult_impl.h:502:139: warning: array subscript [1, 268435456] is outside array bounds of ‘struct secp256k1_strauss_point_state[1]’ [-Warray-bounds]
502 | secp256k1_fe_mul(state->zr + np * ECMULT_TABLE_SIZE(WINDOW_A), state->zr + np * ECMULT_TABLE_SIZE(WINDOW_A), &(a[state->ps[np].input_pos].z));
| ~~~~~~~~~~~~~^~~~~~~~~~
src/ecmult_impl.h:565:42: note: while referencing ‘ps’
565 | struct secp256k1_strauss_point_state ps[1];
| ^~
```
(see https://github.com/bitcoin-core/secp256k1/issues/834)
ACKs for top commit:
fanquake:
ACK 5803f5f5f6030e69b46a46f0511b8173bf89de0d - performed the update myself and got the same change: [check_20257_subtree](https://github.com/fanquake/bitcoin/tree/check_20257_subtree).
hebasto:
ACK 5803f5f5f6030e69b46a46f0511b8173bf89de0d, tested on Linux Mint 20 (x86_64) with `gcc (Ubuntu 9.3.0-17ubuntu1~20.04) 9.3.0` -- no warnings are emitted.
Tree-SHA512: 386281d23aee93a3b1d1a09fec8319c3a477e46967430c935677eed54abddc62d5a7710f9eeab1ec476ace05adcb194b5b377712e44a6bb95a74ffa35faf77f3
52380bf304b1c02dda23f1e2fad0159e29b2f7a2 Squashed 'src/secp256k1/' changes from 8ab24e8dad..c6b6b8f1bb (Pieter Wuille)
Pull request description:
This updates the libsecp256k1 subtree to the latest master, which includes:
* Enabling the GLV endomorphism optimization by default (and removing support for the non-GLV EC multiplication)
* Added a proof for the correctness of the lambda split algorithm by roconnor-blockstream (other code was relying on the fact that it always outputs 128 bit results, which isn't at all obvious).
* Improved exhaustive tests, in particular for the Schnorr signature module
* Various other testing and CI improvements
ACKs for top commit:
fanquake:
ACK 9e5626d2a8ddbbd7640ff53f89f3a7021d747633 - performed a squash and checked that the changes were the same. The non-endomorphism code has now been ripped out.
benthecarman:
ACK 9e5626d
Tree-SHA512: 50fda5f3f934ee525f01cfc15e4f5efbc5261a97f2b77fe1b3453ee0edcf1281ad74ab4532a2fe1fe907652dd47023beff8cf3d73bf34f65ac914a694b9e7110
b9c1a7648131c5deec9704ee9acd00ec1820b9ce Squashed 'src/secp256k1/' changes from 2ed54da18a..8ab24e8dad (Pieter Wuille)
Pull request description:
This updates our src/secp256k1 subtree to the latest libsecp256k1 upstream version.
As it adds BIP340 support (see https://github.com/bitcoin-core/secp256k1/pull/558), this is a prerequisite for #17977. In particular, it contains:
* A few generic library improvements
* Support for x-only public keys as used by BIP340.
* Support for "key pair" objects, making signing more efficient by using a precomputed public key.
* Signing support for BIP340 Schnorr (single-party) signatures.
* Verification support for BIP340 Schnorr signatures.
* Support for verifying tweaked x-only keys, as used by BIP341's Taproot construction.
Things that are not included:
* MuSig, nor any kind of multisignatures, threshold signatures, ... on top.
* Batch verification.
* Support for variable-length messages in BIP340 (which are still being discussed, but won't affect BIP341, or Bitcoin Core).
* A few more generic improvements that are still in the pipeline, including faster modular inversions.
ACKs for top commit:
instagibbs:
ACK 894fb33f4c1b24667891f7d2aff9f486177b1173
fanquake:
ACK 894fb33f4c1b24667891f7d2aff9f486177b1173. Any Valgrind concerns will be addressed upstream, see discussion in https://github.com/bitcoin-core/secp256k1/pull/813, and if necessary, can be pulled into our tree prior to the 0.21.0 branch off. They are not a blocker for merging this PR in it's current state.
benthecarman:
ACK `894fb33`
Tree-SHA512: 6dc992f4477069b7fbd223316f1be955750923be1479c38adad2312649fdca1f316edb375c42ef9d97cea2407caaef49fb8c93abd6c037fe1a522910cbbc2479
54245985fb3c89d72e285c4db39d38ed2f5fb0de Squashed 'src/secp256k1/' changes from 0b70241850..b19c000063 (Pieter Wuille)
Pull request description:
It's been 1.5 years since our secp256k1 subtree was updated, while the upstream project has undergone a number of incremental improvements (performance, tests, build system fixes), plus gained the groundwork for batch verification.
As we're early in the 0.19 window, this seems like a good time to get these merged.
ACKs for commit 99df27:
fanquake:
utACK 99df276 the subtree merge, still need to test the actual changes.
laanwj:
utACK 99df276da
Tree-SHA512: 769a699366321635068ebfbd9d3f30f6e72401c4fcdc1fdc84e5b3fd888c3f01437748f6cd23a507ab47cf04c226cd504fd48aee654457c34bb106c9db7e5c09
fd86f998f Squashed 'src/secp256k1/' changes from 84973d393..0b7024185 (MarcoFalke)
Pull request description:
The subtree should now match upstream again. Check with:
```sh
./contrib/devtools/git-subtree-check.sh src/secp256k1
```
The changes are only documentation/refactoring related.
Tree-SHA512: 43e8a95bcbfefef9e19ec38a92d2d57fdd4a16ddf726e036d36a0d806eb6f35b45b40ee69f980430e107895ec8725b5de4e36456b026214675e0b19630bb6fe9
Note: This is added to our existing automake targets rather than as a
libtool-style lib. The switch to libtool-style targets can come later if it
proves to not add any complications.
