5d8f53e312 Remove redudent checks. (Russell O'Connor)
Pull request description:
These abs checks are implied by the subsequent line, and with the subsequent line written as it is, no underflow is possible with signed integers.
Follows up on https://github.com/bitcoin-core/secp256k1/pull/1218.
ACKs for top commit:
sipa:
utACK 5d8f53e312
real-or-random:
ACK 5d8f53e312
Tree-SHA512: ddd6758638fe634866fdaf900224372e2e51cb81ef4d024f169fbc39fff38ef1b29e90e0732877e8910158b82bc428ee9c3a4031882c2850b22ad87cc63ee305
b43dd83b43 musig: add missing static keyword to function (Jonas Nick)
068e6a036a musig: add test vectors from BIP MuSig (Jonas Nick)
36621d13be musig: update to BIP v1.0.0-rc.2 "Add ''pk'' arg to ''NonceGen''" (Jonas Nick)
d717a4980b musig: update to BIP v0.8 "Switch from X-only to plain pk inputs." (Jonas Nick)
304f1bc96d extrakeys: add pubkey_sort test vectors from BIP MuSig2 (Jonas Nick)
ae89051547 extrakeys: replace xonly_sort with pubkey_sort (Jonas Nick)
98242fcdd9 extrakeys: add secp256k1_pubkey_cmp (Jonas Nick)
73d5b6654d musig: update to BIP v0.7.0 (NonceGen) (Jonas Nick)
060887e9d7 musig: update to BIP v0.5.1 "Rename ordinary tweaking to plain" (Jonas Nick)
cbe2815633 musig: update to BIP v0.4 "Allow the output of NonceAgg to be inf" (Jonas Nick)
206017d67d musig: update to BIP v0.3 (NonceGen) (Jonas Nick)
d800dd55db musig: remove test vectors (Jonas Nick)
Pull request description:
Version 1.0.0-rc.3 of BIP MuSig2 can be found [here](https://github.com/jonasnick/bips/pull/75). This PR does _not_ implement the following optional features that have been added to BIP MuSig2:
- variable length messages
- deterministic signing
- identifiable aborts
The PR also does _not_ yet change the `secnonce` structure to also contain the signer's public key (which would also imply changing the seckey argument in `sign` to a keypair). Additionally, we may want to rename some things in the future to be more consistent with the BIP (e.g. keyagg_cache vs. keyagg_ctx, applytweak vs. tweak_add).
ACKs for top commit:
ariard:
Light Code Review ACK b43dd83b, mostly looks on how the user API will make sense for Lightning, thanks for the answers!
real-or-random:
ACK b43dd83b43
Tree-SHA512: 9b1410951b55a1b0e6590b8c302052996d1fb6d9771765498b4282ff68b44ab0d6add8144c9330217b682ec5a93508b5546099db9a1f2c865f99253010dd76f4
The implementation calls the secp256k1_modinvNN_jacobi_var code, falling back
to computing a square root in the (extremely rare) case it failed converge.
This introduces variants of the divsteps-based GCD algorithm used for
modular inverses to compute Jacobi symbols. Changes compared to
the normal vartime divsteps:
* Only positive matrices are used, guaranteeing that f and g remain
positive.
* An additional jac variable is updated to track sign changes during
matrix computation.
* There is (so far) no proof that this algorithm terminates within
reasonable amount of time for every input, but experimentally it
appears to almost always need less than 900 iterations. To account
for that, only a bounded number of iterations is performed (1500),
after which failure is returned. In VERIFY mode a lower iteration
count is used to make sure that callers exercise their fallback.
* The algorithm converges to f=g=gcd(f0,g0) rather than g=0. To keep
this test simple, the end condition is f=1, which won't be reached
if started with non-coprime or g=0 inputs. Because of that we only
support coprime non-zero inputs.
e089eecc1e group: Further simply gej_add_ge (Tim Ruffing)
ac71020ebe group: Save a normalize_to_zero in gej_add_ge (Tim Ruffing)
Pull request description:
As discovered by sipa in #1033.
See commit message for reasoning but note that the infinity handling will be replaced in the second commit again.
ACKs for top commit:
sipa:
ACK e089eecc1e
apoelstra:
ACK e089eecc1e
Tree-SHA512: fb1b5742e73dd8b2172b4d3e2852490cfd626e8673b72274d281fa34b04e9368a186895fb9cd232429c22b14011df136f4c09bdc7332beef2b3657f7f2798d66
- 0.7.0: Change ''NonceGen'' such that output when message is not present is different from when message is present but has length 0.
- 0.6.0: Change order of arguments and serialization of the message in the ''NonceGen'' hash function
Silence a compiler warning about an unitialized use of a scalar in case
the user tries to provide a 0-length list of commitments.
Also ensures that commitments have normalized field elements when they
are loaded into ges.
