Merge branch '1.0' into 'main'

.clang-format

@@ -0,0 +1,5 @@
+---
+Language:        Cpp
+BasedOnStyle:  LLVM
+...
+

.github/workflows/build.yml

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+name: CMake build & run workflow
+on: push
+jobs:
+  check_codestyle:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Check codestyle
+      run: git ls-files '*.c' '*.h' '*.cpp' '*.hpp' | xargs clang-format -i --verbose && git diff --exit-code
+  preset_release:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Configure CMake
+      run: cmake --preset release
+    - name: Build
+      run: cmake --build --preset release
+    - name: Run
+      run: build/bin/blkchn

.gitignore

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+.vscode
+build
+bin
+obj

CMakeLists.txt

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+cmake_minimum_required(VERSION 3.22)
+
+project(blkchn)
+
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR}/cmake)
+include(CompileOptions)
+
+find_package(OpenSSL REQUIRED)
+
+find_program(CLANG_TIDY_EXE NAMES clang-tidy-14 clang-tidy)
+if(NOT CLANG_TIDY_EXE)
+    message(WARNING "clang-tidy not found")
+else()
+    execute_process(
+        COMMAND ${CLANG_TIDY_EXE} --version
+        OUTPUT_VARIABLE CLANG_TIDY_VERSION
+    )
+    message("clang-tidy found:\n" ${CLANG_TIDY_VERSION})
+endif()
+
+add_subdirectory(src)

CMakePresets.json

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+{
+    "version": 3,
+    "cmakeMinimumRequired": {
+        "major": 3,
+        "minor": 22,
+        "patch": 0
+    },
+    "configurePresets": [
+        {
+            "name": "base",
+            "generator": "Unix Makefiles",
+            "hidden": true
+        },
+        {
+            "name": "release",
+            "inherits": "base",
+            "binaryDir": "${sourceDir}/build"
+        }
+    ],
+    "buildPresets": [
+        {
+            "name": "release",
+            "configurePreset": "release",
+            "jobs": 4
+        }
+    ]
+}

README.md

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+# blkchn
+![GitHub last commit](https://img.shields.io/github/last-commit/allenvox/blkchn)<br>
+C++ blockchain examples
+
+**Requirements:** OpenSSL<br>
+**Build:** `cmake --preset release && cmake --build --preset release`<br>
+**Run:** `build/bin/blkchn`<br>

cmake/CompileOptions.cmake

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+function(set_compile_options target_name)
+    target_compile_options(${target_name} PRIVATE -Wall -Wextra -Werror -pedantic)
+    set_target_properties(
+        ${target_name}
+        PROPERTIES
+        CXX_STANDARD 17
+        CXX_STANDARD_REQUIRED ON
+        CXX_EXTENSIONS OFF
+    )
+    if(CLANG_TIDY_EXE)
+        set_target_properties(
+            ${target_name}
+            PROPERTIES
+            CXX_CLANG_TIDY ${CLANG_TIDY_EXE}
+        )
+    endif()
+endfunction()

src/CMakeLists.txt

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+add_subdirectory(blkchn)

src/blkchn/CMakeLists.txt

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+set(target_name blkchn)
+
+add_executable(${target_name})
+set_compile_options(${target_name})
+
+target_sources(
+    ${target_name}
+    PRIVATE
+    main.cpp
+)
+
+target_link_libraries(
+    ${target_name}
+    OpenSSL::SSL
+    OpenSSL::Crypto
+)

src/blkchn/main.cpp

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+#include <openssl/sha.h>
+
+#include <ctime>
+#include <iostream>
+#include <sstream>
+#include <string>
+#include <vector>
+
+std::string calculateHash(const std::string &data) {
+  unsigned char hash[SHA256_DIGEST_LENGTH];
+  SHA256(reinterpret_cast<const unsigned char *>(data.c_str()), data.size(),
+         hash);
+
+  std::stringstream ss;
+  for (size_t i = 0; i < SHA256_DIGEST_LENGTH; ++i) {
+    ss << std::hex << (int)hash[i];
+  }
+
+  return ss.str();
+}
+
+struct Block {
+  int index;
+  std::string data;
+  std::string prevHash;
+  std::string hash;
+  time_t timestamp;
+
+  std::string getSignature() {
+    return std::to_string(index) + std::to_string(timestamp) + data + prevHash;
+  }
+
+  Block(int idx, const std::string &info, const std::string &previousHash)
+      : index(idx), data(info), prevHash(previousHash),
+        timestamp(time(nullptr)) {
+    hash = calculateHash(getSignature());
+  }
+};
+
+class Blockchain {
+public:
+  Blockchain() { chain.push_back(createGenesisBlock()); }
+
+  void addBlock(const std::string &data) {
+    Block newBlock(chain.size(), data, chain.back().hash);
+    chain.push_back(newBlock);
+  }
+
+  bool isChainValid() {
+    for (size_t i = 1; i < chain.size(); ++i) {
+      auto result = calculateHash(chain[i].getSignature());
+      auto expected = chain[i].hash;
+      if (expected != result) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  void printChain() const {
+    for (const auto &block : chain) {
+      std::cout << "Index: " << block.index
+                << ", Timestamp: " << block.timestamp
+                << "\nData: " << block.data << "\nHash: " << block.hash
+                << "\nPrevious Hash: " << block.prevHash
+                << "\n----------------\n";
+    }
+  }
+
+private:
+  std::vector<Block> chain;
+
+  Block createGenesisBlock() { return Block(0, "Genesis Block", "0"); }
+};
+
+int main() {
+  Blockchain myBlockchain;
+
+  myBlockchain.addBlock("Alexei paid Yuriy $50");
+  myBlockchain.addBlock("Yuriy paid Mikhail $30");
+
+  std::cout << "Blockchain is " << (myBlockchain.isChainValid() ? "" : " not ")
+            << "valid\n";
+
+  std::cout << "\nThe blockchain is:\n----------------\n";
+  myBlockchain.printChain();
+
+  return 0;
+}