crypto/secp256k1: update libsecp256k1 (ethereum#31242)

Updates the libsecp256k1 dependency to commit:
c0d9480fbbf8eccbd4be23ed27f6f2af6f3b211e

PR:
```
BenchmarkSign-24    	   57756	     21214 ns/op	     164 B/op	       3 allocs/op
BenchmarkRecover-24    	   37156	     33044 ns/op	      80 B/op	       1 allocs/op
BenchmarkEcrecoverSignature-24    	   36889	     32935 ns/op	      80 B/op	       1 allocs/op
BenchmarkVerifySignature-24    	   41163	     29207 ns/op	       0 B/op	       0 allocs/op
BenchmarkDecompressPubkey-24    	  318624	      4062 ns/op	     304 B/op	       6 allocs/op
```

Master:
```
BenchmarkSign-24    	   34509	     35330 ns/op	     164 B/op	       3 allocs/op
BenchmarkRecover-24    	   25418	     47725 ns/op	      80 B/op	       1 allocs/op
BenchmarkEcrecoverSignature-24    	   25735	     47591 ns/op	      80 B/op	       1 allocs/op
BenchmarkVerifySignature-24    	   29108	     41097 ns/op	       0 B/op	       0 allocs/op
BenchmarkDecompressPubkey-24    	  294747	      4143 ns/op	     304 B/op	       6 allocs/op
```

Performance seems to be improved significantly:
```
Sign-24      34.86µ ± 3%   21.66µ ± 2%  -37.86% (p=0.000 n=10)
Recover-24   46.14µ ± 3%   33.24µ ± 2%  -27.95% (p=0.000 n=10)
```

Author: MariusVanDerWijden

crypto/secp256k1/ext.h

@@ -109,8 +109,8 @@ int secp256k1_ext_scalar_mul(const secp256k1_context* ctx, unsigned char *point,
 	ARG_CHECK(scalar != NULL);
 	(void)ctx;
 
-	secp256k1_fe_set_b32(&feX, point);
-	secp256k1_fe_set_b32(&feY, point+32);
+	secp256k1_fe_set_b32_limit(&feX, point);
+	secp256k1_fe_set_b32_limit(&feY, point+32);
 	secp256k1_ge_set_xy(&ge, &feX, &feY);
 	secp256k1_scalar_set_b32(&s, scalar, &overflow);
 	if (overflow || secp256k1_scalar_is_zero(&s)) {

crypto/secp256k1/libsecp256k1/.cirrus.yml

@@ -0,0 +1,101 @@
+env:
+  ### cirrus config
+  CIRRUS_CLONE_DEPTH: 1
+  ### compiler options
+  HOST:
+  WRAPPER_CMD:
+  # Specific warnings can be disabled with -Wno-error=foo.
+  # -pedantic-errors is not equivalent to -Werror=pedantic and thus not implied by -Werror according to the GCC manual.
+  WERROR_CFLAGS: -Werror -pedantic-errors
+  MAKEFLAGS: -j4
+  BUILD: check
+  ### secp256k1 config
+  ECMULTWINDOW: 15
+  ECMULTGENKB: 22
+  ASM: no
+  WIDEMUL: auto
+  WITH_VALGRIND: yes
+  EXTRAFLAGS:
+  ### secp256k1 modules
+  EXPERIMENTAL: no
+  ECDH: no
+  RECOVERY: no
+  EXTRAKEYS: no
+  SCHNORRSIG: no
+  MUSIG: no
+  ELLSWIFT: no
+  ### test options
+  SECP256K1_TEST_ITERS: 64
+  BENCH: yes
+  SECP256K1_BENCH_ITERS: 2
+  CTIMETESTS: yes
+  # Compile and run the tests
+  EXAMPLES: yes
+
+cat_logs_snippet: &CAT_LOGS
+  always:
+    cat_tests_log_script:
+      - cat tests.log || true
+    cat_noverify_tests_log_script:
+      - cat noverify_tests.log || true
+    cat_exhaustive_tests_log_script:
+      - cat exhaustive_tests.log || true
+    cat_ctime_tests_log_script:
+      - cat ctime_tests.log || true
+    cat_bench_log_script:
+      - cat bench.log || true
+    cat_config_log_script:
+      - cat config.log || true
+    cat_test_env_script:
+      - cat test_env.log || true
+    cat_ci_env_script:
+      - env
+
+linux_arm64_container_snippet: &LINUX_ARM64_CONTAINER
+  env_script:
+    - env | tee /tmp/env
+  build_script:
+    - DOCKER_BUILDKIT=1 docker build --file "ci/linux-debian.Dockerfile" --tag="ci_secp256k1_arm"
+    - docker image prune --force  # Cleanup stale layers
+  test_script:
+    - docker run --rm --mount "type=bind,src=./,dst=/ci_secp256k1" --env-file /tmp/env --replace --name "ci_secp256k1_arm" "ci_secp256k1_arm" bash -c "cd /ci_secp256k1/ && ./ci/ci.sh"
+
+task:
+  name: "ARM64: Linux (Debian stable)"
+  persistent_worker:
+    labels:
+      type: arm64
+  env:
+    ECDH: yes
+    RECOVERY: yes
+    EXTRAKEYS: yes
+    SCHNORRSIG: yes
+    MUSIG: yes
+    ELLSWIFT: yes
+  matrix:
+     # Currently only gcc-snapshot, the other compilers are tested on GHA with QEMU
+     - env: { CC: 'gcc-snapshot' }
+  << : *LINUX_ARM64_CONTAINER
+  << : *CAT_LOGS
+
+task:
+  name: "ARM64: Linux (Debian stable), Valgrind"
+  persistent_worker:
+    labels:
+      type: arm64
+  env:
+    ECDH: yes
+    RECOVERY: yes
+    EXTRAKEYS: yes
+    SCHNORRSIG: yes
+    MUSIG: yes
+    ELLSWIFT: yes
+    WRAPPER_CMD: 'valgrind --error-exitcode=42'
+    SECP256K1_TEST_ITERS: 2
+  matrix:
+     - env: { CC: 'gcc' }
+     - env: { CC: 'clang' }
+     - env: { CC: 'gcc-snapshot' }
+     - env: { CC: 'clang-snapshot' }
+  << : *LINUX_ARM64_CONTAINER
+  << : *CAT_LOGS

crypto/secp256k1/libsecp256k1/.gitattributes

@@ -0,0 +1,2 @@
+src/precomputed_ecmult.c linguist-generated
+src/precomputed_ecmult_gen.c linguist-generated

crypto/secp256k1/libsecp256k1/.github/actions/install-homebrew-valgrind/action.yml

@@ -0,0 +1,33 @@
+name: "Install Valgrind"
+description: "Install Homebrew's Valgrind package and cache it."
+runs:
+  using: "composite"
+  steps:
+    - run: |
+        brew tap LouisBrunner/valgrind
+        brew fetch --HEAD LouisBrunner/valgrind/valgrind
+        echo "CI_HOMEBREW_CELLAR_VALGRIND=$(brew --cellar valgrind)" >> "$GITHUB_ENV"
+      shell: bash
+
+    - run: |
+        sw_vers > valgrind_fingerprint
+        brew --version >> valgrind_fingerprint
+        git -C "$(brew --cache)/valgrind--git" rev-parse HEAD >> valgrind_fingerprint
+        cat valgrind_fingerprint
+      shell: bash
+
+    - uses: actions/cache@v4
+      id: cache
+      with:
+        path: ${{ env.CI_HOMEBREW_CELLAR_VALGRIND }}
+        key: ${{ github.job }}-valgrind-${{ hashFiles('valgrind_fingerprint') }}
+
+    - if: steps.cache.outputs.cache-hit != 'true'
+      run: |
+        brew install --HEAD LouisBrunner/valgrind/valgrind
+      shell: bash
+
+    - if: steps.cache.outputs.cache-hit == 'true'
+      run: |
+        brew link valgrind
+      shell: bash

crypto/secp256k1/libsecp256k1/.github/actions/run-in-docker-action/action.yml

@@ -0,0 +1,54 @@
+name: 'Run in Docker with environment'
+description: 'Run a command in a Docker container, while passing explicitly set environment variables into the container.'
+inputs:
+  dockerfile:
+    description: 'A Dockerfile that defines an image'
+    required: true
+  tag:
+    description: 'A tag of an image'
+    required: true
+  command:
+    description: 'A command to run in a container'
+    required: false
+    default: ./ci/ci.sh
+runs:
+  using: "composite"
+  steps:
+    - uses: docker/setup-buildx-action@v3
+
+    - uses: docker/build-push-action@v5
+      id: main_builder
+      continue-on-error: true
+      with:
+        context: .
+        file: ${{ inputs.dockerfile }}
+        tags: ${{ inputs.tag }}
+        load: true
+        cache-from: type=gha
+
+    - uses: docker/build-push-action@v5
+      id: retry_builder
+      if: steps.main_builder.outcome == 'failure'
+      with:
+        context: .
+        file: ${{ inputs.dockerfile }}
+        tags: ${{ inputs.tag }}
+        load: true
+        cache-from: type=gha
+
+    - # Workaround for https://github.com/google/sanitizers/issues/1614 .
+      # The underlying issue has been fixed in clang 18.1.3.
+      run: sudo sysctl -w vm.mmap_rnd_bits=28
+      shell: bash
+
+    - # Tell Docker to pass environment variables in `env` into the container.
+      run: >
+        docker run \
+          $(echo '${{ toJSON(env) }}' | jq -r 'keys[] | "--env \(.) "') \
+          --volume ${{ github.workspace }}:${{ github.workspace }} \
+          --workdir ${{ github.workspace }} \
+          ${{ inputs.tag }} bash -c "
+            git config --global --add safe.directory ${{ github.workspace }}
+            ${{ inputs.command }}
+          "
+      shell: bash