init

.github/workflows/codeql.yml

@@ -0,0 +1,39 @@
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+  schedule:
+    - cron: '0 19 * * 0'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ 'go' ]
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      # Initializes the CodeQL tools for scanning.
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v2
+        with:
+          languages: ${{ matrix.language }}
+
+      - name: Autobuild
+        uses: github/codeql-action/autobuild@v2
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v2

.github/workflows/lint.yml

@@ -0,0 +1,42 @@
+name: Lint
+
+on:
+  push:
+
+jobs:
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go: [1.16, 1.17, 1.18]
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 2
+
+      - name: Setup go
+        id: go
+        uses: actions/setup-go@v2
+        with:
+          go-version: ${{ matrix.go }}
+
+      - name: Cache go
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.cache/go-build
+            ~/go/pkg/mod
+          key: ${{ runner.os }}-go-v${{ matrix.go }}-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-go-
+
+      - name: Golangci lint
+        uses: golangci/golangci-lint-action@v3
+        with:
+          version: v1.45.2
+          skip-pkg-cache: true
+          skip-build-cache: true
+          only-new-issues: true
+          args: -v ./...

.github/workflows/tests.yml

@@ -0,0 +1,51 @@
+name: Tests
+
+on:
+  push:
+  schedule:
+    - cron: '0 19 * * 0'
+
+jobs:
+  test:
+    name: Tests
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go: [1.16, 1.17, 1.18]
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 2
+
+      - name: Setup go
+        id: go
+        uses: actions/setup-go@v2
+        with:
+          go-version: ${{ matrix.go }}
+
+      - name: Cache go
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.cache/go-build
+            ~/go/pkg/mod
+          key: ${{ runner.os }}-go-v${{ matrix.go }}-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-go-
+
+      - name: Run tests
+        id: test
+        run: |
+          make test
+          echo "::set-output name=coverage::$(make coverage)"
+
+      - name: Create Coverage Badge
+        uses: schneegans/[email protected]
+        with:
+          auth: ${{ secrets.GIST_SECRET }}
+          gistID: cce912d48b587ba656b45a0cba34510b
+          filename: pow-hc-test-coverage.json
+          label: Coverage
+          message: ${{ steps.test.outputs.coverage }}
+          color: green

.gitignore

@@ -0,0 +1,4 @@
+.idea
+.DS_Store
+
+coverage.txt

.golangci.yml

@@ -0,0 +1,46 @@
+# This file contains all available configuration options
+# with their default values.
+
+# options for analysis running
+run:
+  # timeout for analysis, e.g. 30s, 5m, default is 1m
+  timeout: 5m
+
+  # include test files or not, default is true
+  tests: false
+
+linters:
+  disable:
+    - scopelint
+  enable:
+    - errcheck
+    - goimports
+    - gofmt
+    - revive
+    - exportloopref
+    - prealloc
+    - lll
+    - whitespace
+    - unconvert
+    - goconst
+    - staticcheck
+    - govet
+    - gocritic
+  presets:
+    - bugs
+    - unused
+
+linters-settings:
+  lll:
+    line-length: 180
+  revive:
+    ignore-generated-header: true
+    rules:
+      - name: unexported-return
+        disabled: true
+
+issues:
+  exclude-rules:
+    - linters:
+        - lll
+      source: "^//go:generate "

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2022 Kirill Rodin
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

Makefile

@@ -0,0 +1,22 @@
+.PHONY: install
+install:
+	@go mod tidy
+	@go install \
+	  github.com/abice/go-enum \
+	  github.com/golang/mock/mockgen
+
+.PHONY: gen
+gen: install
+	@go generate ./...
+
+.PHONY: test
+test: gen
+	@go test $$(go list ./... | grep -v /mock) -coverprofile=coverage.txt -covermode=atomic -timeout 60s
+
+.PHONY: coverage
+coverage:
+	@make test | tr -d '\n' | sed -e 's/.*coverage:\(.*\)of statements.*/\1/' | tr -d '\n '
+
+.PHONY: lint
+lint:
+	@golangci-lint --timeout 10m0s run

README.md

@@ -0,0 +1,82 @@
+# Hashcash
+
+[![GoDoc](https://img.shields.io/badge/reference-007d9c.svg?logo=go&logoColor=white&label=doc)](https://pkg.go.dev/github.com/PoW-HC/hashcash)
+[![Go Report Card](https://goreportcard.com/badge/github.com/PoW-HC/hashcash)](https://goreportcard.com/report/github.com/PoW-HC/hashcash)
+[![Lint](https://github.com/PoW-HC/hashcash/actions/workflows/lint.yml/badge.svg)](https://github.com/PoW-HC/hashcash/actions/workflows/lint.yml)
+[![Tests](https://github.com/PoW-HC/hashcash/actions/workflows/tests.yml/badge.svg)](https://github.com/PoW-HC/hashcash/actions/workflows/tests.yml)
+![Coverage](https://img.shields.io/endpoint?url=https://gist.githubusercontent.com/halfi/cce912d48b587ba656b45a0cba34510b/raw/pow-hc-test-coverage.json)
+[![Code quality](https://github.com/PoW-HC/hashcash/actions/workflows/codeql.yml/badge.svg)](https://github.com/PoW-HC/hashcash/actions/workflows/codeql.yml)
+[![license](https://img.shields.io/github/license/PoW-HC/hashcash)](https://github.com/PoW-HC/hashcash/blob/main/LICENSE)
+
+---
+
+Hashcash is a Go library which implements the hashcash [proof-of-work](https://en.wikipedia.org/wiki/Proof_of_work)
+algorithm. Hashcash has been used as a denial-of-service counter measure technique in a number of systems. To learn more
+about hashcash visit [official page](http://hashcash.org/).
+
+## Usage
+
+Computing a valid hashcash:
+
+```go
+package main
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/PoW-HC/hashcash/pkg/hash"
+	"github.com/PoW-HC/hashcash/pkg/pow"
+)
+
+const maxIterations = 1 << 30
+
+func main() {
+	hasher, err := hash.NewHasher("sha256")
+	if err != nil {
+		// handle error
+	}
+
+	p := pow.New(hasher)
+
+	hashcash, err := pow.InitHashcash(5, "127.0.0.1", pow.SignExt("secret", hasher))
+	if err != nil {
+		// handle error
+	}
+
+	solution, err := p.Compute(context.Background(), hashcash, maxIterations)
+	if err != nil {
+		// handle error
+	}
+	fmt.Println(solution)
+}
+
+```
+
+Outputs:
+
+```
+1:5:1649257375:127.0.0.1:41965c8500f67f79b35672d7fb7e19fe5af0d51da582cbfcdbedb0f5944198bb:MgjmhCBiRV4=:MTk3YzA0
+```
+
+```shell
+echo -n "1:5:1649257375:127.0.0.1:41965c8500f67f79b35672d7fb7e19fe5af0d51da582cbfcdbedb0f5944198bb:MgjmhCBiRV4=:MTk3YzA0" | shasum -a 256
+0000067c716fa612cee5eb31eab6163e804c002841cfe96cc81f4f8034fd6006  -
+```
+
+Verification token:
+
+```go
+	err := p.Verify(solution, "127.0.0.1")
+	if err != nil {
+		// hashcash token failed verification.
+	}
+```
+
+## Documentation
+
+https://pkg.go.dev/github.com/PoW-HC/hashcash
+
+## License
+
+See the [LICENSE](LICENSE.md) file for license rights and limitations (MIT).

go.mod

@@ -0,0 +1,21 @@
+module github.com/PoW-HC/hashcash
+
+go 1.16
+
+require (
+	github.com/abice/go-enum v0.4.0
+	github.com/golang/mock v1.6.0
+	github.com/minio/sha256-simd v1.0.0
+	github.com/stretchr/testify v1.7.1
+)
+
+require (
+	github.com/google/uuid v1.3.0 // indirect
+	github.com/klauspost/cpuid/v2 v2.0.12 // indirect
+	github.com/kr/pretty v0.3.0 // indirect
+	github.com/mattn/go-colorable v0.1.12 // indirect
+	github.com/mitchellh/copystructure v1.2.0 // indirect
+	golang.org/x/crypto v0.0.0-20220331220935-ae2d96664a29 // indirect
+	golang.org/x/mod v0.6.0-dev.0.20220330205332-605edab4323b // indirect
+	golang.org/x/sys v0.0.0-20220405210540-1e041c57c461 // indirect
+)