ade5b36701 tests: add checks for scalar constants `secp256k1_scalar_{zero,one}` (Sebastian Falbesoner)
654246c635 refactor: take use of `secp256k1_scalar_{zero,one}` constants (Sebastian Falbesoner)
Pull request description:
Rather than allocating a (non-constant) scalar variable on the stack with the sole purpose of setting it to a constant value, the global constants `secp256k1_scalar_{zero,one}` (apparently introduced in 34a67c773b, PR #710) can be directly used instead for the values 0 or 1. There is very likely not even a difference in run-time, but it leads to simpler and less code which might be nice.
ACKs for top commit:
sipa:
utACK ade5b36701
real-or-random:
utACK ade5b36701
Tree-SHA512: 0ff05a449c153f7117a4a56efef04b2087c2330f4692f3390a0b1d95573785ac7ae3fe689ed0ec2ecc64b575d2489d6e341d32567e75a1a4b4d458c3ecd406a1
a575339c02 Remove bits argument from secp256k1_wnaf_const (always 256) (Pieter Wuille)
Pull request description:
There is little reason for having the number of bits in the scalar as a parameter, as I don't think there are any (current) use cases for non-256-bit scalars.
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jonasnick:
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real-or-random:
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Tree-SHA512: 994b1f19b4c513f6d070ed259a5d6f221a0c2450271ec824c5eba1cd0ecace276de391c170285bfeae96aaf8f1e0f7fe6260966ded0336c75c522ab6c56d182c
e5de454609 tests: Add Wycheproof ECDSA vectors (RandomLattice)
Pull request description:
This PR adds a test using the Wycheproof vectors as outlined in #1106. We add all 463 ECDSA test vectors. These vectors cover:
- edge cases in arithmetic operations
- signatures with special values for (r,s) that should be rejected
- special cases of public keys
The vectors are pulled from the Wycheproof project using a python script to emit C code.
All the new ECDSA Wycheproof vectors pass.
ACKs for top commit:
sipa:
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real-or-random:
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Tree-SHA512: e9684f14ff3f5225a4a4949b490e07527d559c28aa61ed03c03bc52ea64785f0b80b9e1b1628665eacf24006526271ea0fb108629c9c3c1d758e52d214a056f1
Adds a test using the Wycheproof vectors as outlined in #1106. The
vectors are taken from the Wycheproof repo. We use a python script
to convert the JSON-formatted vectors into C code.
Co-authored-by: Sean Andersen <6730974+andozw@users.noreply.github.com>
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.
d216475205 test secp256k1_i128_to_i64 (Russell O'Connor)
4bc429019d Add a secp256k1_i128_to_u64 function. (Russell O'Connor)
Pull request description:
I wanted to experiment with what would be required to split up `secp256k1_i128_to_i64` between those cases when a signed 64 bit value is being demoted, versus an unsigned 64 bit value is being extracted from the lower bits, and this is the result.
I'm not sure this is a useful PR, so feel free to close it. However, since it is already written, I figured it is worth at least discussing.
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sipa:
utACK d216475205
real-or-random:
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Tree-SHA512: 41dbb1d33b3078bee8e71a838cfad6f1859c0bba602ae061259add8e9e8ea5aa482daa41de79dbd7433ddbef4a0bc52757f3c45d63acc9c0eb05aa3ca891b922
This change eases the use of alternate build systems by moving
the variables in `src/libsecp256k1-config.h` to compiler macros
for each invocation, preventing duplication of these variables
for each build system.
Co-authored-by: Ali Sherief <ali@notatether.com>
