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
