introduced and used bigint datatype

.github/workflows/cmake.yaml

@@ -15,17 +15,35 @@ jobs:
     # The CMake configure and build commands are platform agnostic and should work equally well on Windows or Mac.
     # You can convert this to a matrix build if you need cross-platform coverage.
     # See: https://docs.github.com/en/free-pro-team@latest/actions/learn-github-actions/managing-complex-workflows#using-a-build-matrix
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
 
     steps:
     - uses: actions/checkout@v3
     - name: Prepare dependencies
-      run: sudo apt-get update && sudo apt-get install -yq libboost-system-dev libboost-date-time-dev cmake graphviz doxygen
+      run:   |
+         if [ "$RUNNER_OS" == "Linux" ]; then
+              sudo apt-get update && \
+              sudo apt-get install -yq \
+                libboost-system-dev \
+                libboost-date-time-dev \
+                cmake \
+                graphviz doxygen
+         elif [ "$RUNNER_OS" == "Windows" ]; then
+              choco install boost-msvc-14.3 graphviz doxygen.install
+         elif [ "$RUNNER_OS" == "macOS" ]; then
+              brew install boost graphviz doxygen
+         else
+              echo "$RUNNER_OS not supported"
+              exit 1
+         fi
+      shell: bash      
     - name: Configure CMake
-      # Configure CMake in a 'build' subdirectory. `CMAKE_BUILD_TYPE` is only required if you are using a single-configuration generator such as make.
+      run: cmake -B ${{github.workspace}}/build \
-      # See https://cmake.org/cmake/help/latest/variable/CMAKE_BUILD_TYPE.html?highlight=cmake_build_type
+                 -D CMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} 
-      run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}}
-
     - name: Build
       # Build your program with the given configuration
       run: cmake --build ${{github.workspace}}/build --config ${{env.BUILD_TYPE}}
@@ -35,4 +53,3 @@ jobs:
       # Execute tests defined by the CMake configuration.
       # See https://cmake.org/cmake/help/latest/manual/ctest.1.html for more detail
       run: ctest -C ${{env.BUILD_TYPE}}
-

.github/workflows/doxygen-gh-pages.yml

@@ -0,0 +1,29 @@
+name: Doxygen Github Pages Deploy action
+
+on:
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: write
+jobs:
+  build-and-deploy:
+    concurrency: ci-${{ github.ref }} # Recommended if you intend to make multiple deployments in quick succession.
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout 🛎️
+        uses: actions/checkout@v3
+      - name: Prepare dependencies
+        run: sudo apt-get update && sudo apt-get install -yq libboost-system-dev libboost-date-time-dev cmake graphviz doxygen
+      - name: configure
+        run: cmake -B build -S . -DEXPATPP_BUILD_DOCS=ON
+      - name: clean generated docs dir
+        run: rm -rf build/html
+      - name: build
+        run: cmake --build build --target doc
+
+      - name: Deploy 🚀
+        uses: JamesIves/github-pages-deploy-action@v4
+        with:
+          folder: build/html # The folder the action should deploy.

CMakeLists.txt

@@ -71,7 +71,7 @@ doxygen_add_docs(
 )
 
 # build common library
-set(LIB_SOURCES src/model.cpp src/model.hpp)
+set(LIB_SOURCES src/model.cpp src/model.hpp src/big_int.hpp src/big_int.cpp)
 add_library(oc-mint-lib ${LIB_SOURCES})
 target_link_libraries(oc-mint-lib PUBLIC Crow::Crow)
 target_include_directories(oc-mint-lib PUBLIC ${expected_SOURCE_DIR}/include src) 
@@ -80,7 +80,7 @@ add_executable(oc-mint src/main.cpp)
 target_link_libraries(oc-mint PRIVATE oc-mint-lib INTERFACE tl::expected::expected)
 
 ## these are unittests that can be run on any platform
-add_executable(tests test/test.cpp)
+add_executable(tests  test/test_big_int.cpp test/test.cpp)
 target_link_libraries(tests
                       oc-mint-lib
 		      Catch2::Catch2WithMain)

src/big_int.cpp

@@ -0,0 +1,27 @@
+#include "big_int.hpp"
+#include <iostream>
+
+tl::expected<BigInt,BigInt::eError>
+BigInt::from_string(const std::string& str) {
+  BigInt b;
+  std::cout << str << std::endl;
+  b.data = str;
+  return b;
+}
+
+BigInt BigInt::from_int(uint64_t value)
+{
+  BigInt b;
+  b.data = std::to_string(value);
+  return b;
+}
+
+std::string BigInt::to_string() const
+{
+  return data;
+}
+
+bool operator == (const BigInt& rhs, const BigInt& lhs)
+{ return rhs.data == lhs.data; }
+
+

src/big_int.hpp

@@ -0,0 +1,26 @@
+#ifndef BIG_INT_HPP
+#define BIG_INT_HPP
+
+#include <string>
+#include "tl/expected.hpp"
+
+struct BigInt {
+  BigInt() : data() {}
+  virtual ~BigInt() {}
+  enum class eError {
+    PARSE_ERROR
+  };
+
+  
+  std::string data;
+
+  static tl::expected<BigInt,eError> from_string(const std::string& str);
+  static BigInt from_int(uint64_t value);
+  std::string to_string() const;
+};
+
+bool operator == (const BigInt& rhs, const BigInt& lhs); 
+
+#endif // #ifndef #ifndef BIG_INT_HPP
+
+

src/main.cpp

@@ -70,7 +70,8 @@ int main() {
           ResponseMint res;
           res.message_reference = req->message_reference;
 
-          auto minted = model->mint(req->transaction_reference, req->blinds);
+	  /// \todo change argument transaction_reference to bigint
+          auto minted = model->mint(req->transaction_reference.to_string(), req->blinds);
 
           res.blind_signatures = minted;
           res.status_code = crow::status::OK;

src/model.cpp

@@ -1,7 +1,9 @@
 #include "model.hpp"
 #include "crow/json.h"
+#include "tl/expected.hpp"
 
 #define TO_JSON(name) r[#name]=name
+#define BIGINT_TO_JSON(name) r[#name]=name.to_string()
 #define TO_JSON_JSON(name) r[#name]=name.to_json()
 #define TO_JSON_ARRAY(name) r[#name]=list_to_json(name)
 
@@ -22,8 +24,8 @@ crow::json::wvalue list_to_json(const std::vector<unsigned int> &array) {
 
 crow::json::wvalue PublicKey::to_json() const {
   crow::json::wvalue r;
-  TO_JSON(modulus);
+  BIGINT_TO_JSON(modulus);
-  TO_JSON(public_exponent);
+  BIGINT_TO_JSON(public_exponent);
   r["type"]="rsa public key";
   return r;
 }
@@ -48,7 +50,7 @@ crow::json::wvalue CDD::to_json() const {
   TO_JSON(currency_divisor);
   TO_JSON(currency_name);
   TO_JSON_ARRAY(denominations);
-  TO_JSON(id);
+  BIGINT_TO_JSON(id);
   TO_JSON_ARRAY(info_service);
   TO_JSON(issuer_cipher_suite);
   TO_JSON_JSON(issuer_public_master_key);
@@ -75,8 +77,8 @@ crow::json::wvalue MintKey::to_json() const {
   TO_JSON(cdd_serial);
   TO_JSON(coins_expiry_date);
   TO_JSON(denomination);
-  TO_JSON(id);
+  BIGINT_TO_JSON(id);
-  TO_JSON(issuer_id);
+  BIGINT_TO_JSON(issuer_id);
   TO_JSON_JSON(public_mint_key);
 
   TO_JSON(sign_coins_not_after);
@@ -178,7 +180,12 @@ RequestMKCs::from_string(const std::string &str) {
       return tl::make_unexpected(eError::JSON_WRONG_REQUEST_TYPE);
     } else {
       for (auto k: mint_key_ids.lo()) {
-        r.mint_key_ids.push_back(k.u());
+	auto kv = BigInt::from_string(k.s());
+	if (!kv.has_value()) {
+	  return tl::make_unexpected(eError::JSON_PARSE_ERROR);
+	} else {
+	  r.mint_key_ids.push_back(*kv);
+	}
       }
     }
     return r;
@@ -194,23 +201,38 @@ crow::json::wvalue ResponseMKCs::to_json() const {
 
 crow::json::wvalue Blind::to_json() const {
   crow::json::wvalue r;
-  TO_JSON(blinded_payload_hash);
+  BIGINT_TO_JSON(blinded_payload_hash);
-  TO_JSON(mint_key_id);
+  BIGINT_TO_JSON(mint_key_id);
   TO_JSON(reference);
   r["type"] = "blinded payload hash";
   return r;
 }
 
 tl::expected<Blind, eError> Blind::from_json(const crow::json::rvalue &json) {
-  if (!(json.has("type") && json.has("blinded_payload_hash") &&
+  if (!(json.has("type")
-        json.has("mint_key_id") && json.has("reference"))) {
+	&& json.has("blinded_payload_hash")
+	&& json.has("mint_key_id")
+	&& json.has("reference"))) {
     return tl::make_unexpected(eError::JSON_ERROR);
   } else if (json["type"] != "blinded payload hash") {
     return tl::make_unexpected(eError::JSON_ERROR);
   } else {
     Blind r;
-    r.blinded_payload_hash = json["blinded_payload_hash"].s();
+
-    r.mint_key_id = json["mint_key_id"].s();
+    auto hash = BigInt::from_string(json["blinded_payload_hash"].s());
+    if (!hash) {
+      std::cout << "invalid hash : " <<  json["blinded_payload_hash"].s()
+		<< std::endl;
+      return tl::make_unexpected(eError::JSON_PARSE_ERROR);
+    }
+    r.blinded_payload_hash = hash.value();
+
+    auto key_id = BigInt::from_string(json["mint_key_id"].s());
+    if (!key_id) {
+      printf("invalid key_id");
+      return tl::make_unexpected(eError::JSON_PARSE_ERROR);
+    }
+    r.mint_key_id = key_id.value();
     r.reference = json["reference"].s();
     return r;
   }
@@ -218,7 +240,7 @@ tl::expected<Blind, eError> Blind::from_json(const crow::json::rvalue &json) {
 
 crow::json::wvalue BlindSignature::to_json() const {
   crow::json::wvalue r;
-  TO_JSON(blind_signature);
+  BIGINT_TO_JSON(blind_signature);
   TO_JSON(reference);
   r["type"] = "blind signature";
   return r;
@@ -239,7 +261,11 @@ RequestMint::from_string(const std::string &str) {
   } else {
     RequestMint r;
     r.message_reference= json["message_reference"].u();
-    r.transaction_reference = json["transaction_reference"].s();
+    auto tr = BigInt::from_string(json["transaction_reference"].s());
+    if (!tr)
+      return tl::make_unexpected(eError::JSON_PARSE_ERROR);
+      
+    r.transaction_reference = *tr;
     if (json["blinds"].t()!=crow::json::type::List) {
       return tl::make_unexpected(eError::JSON_WRONG_VALUE_TYPE);
     }
@@ -267,10 +293,10 @@ crow::json::wvalue Coin::Payload::to_json() const {
   crow::json::wvalue r;
   TO_JSON(cdd_location);
   TO_JSON(denomination);
-  TO_JSON(issuer_id);
+  BIGINT_TO_JSON(issuer_id);
-  TO_JSON(mint_key_id);
+  BIGINT_TO_JSON(mint_key_id);
   TO_JSON(protocol_version);
-  TO_JSON(serial);
+  BIGINT_TO_JSON(serial);
 
   r["type"] = "payload";
   return r;
@@ -297,10 +323,20 @@ Coin::Payload::from_json(const crow::json::rvalue &json) {
     Coin::Payload payload;
     payload.cdd_location = json["cdd_location"].s();
     payload.denomination = json["denomination"].u();
-    payload.issuer_id = json["issuer_id"].s();
+    auto id = BigInt::from_string(json["issuer_id"].s());
-    payload.mint_key_id = json["mint_key_id"].s();
+    if (!id)
+      tl::make_unexpected(eError::JSON_PARSE_ERROR);
+    payload.issuer_id    = *id;
+
+    id = BigInt::from_string(json["mint_key_id"].s());
+    if (!id)
+      tl::make_unexpected(eError::JSON_PARSE_ERROR);
+    payload.mint_key_id  = *id;
     payload.protocol_version = json["protocol_version"].s();
-    payload.serial = json["serial"].s();
+    id = BigInt::from_string(json["serial"].s());
+    if (!id)
+      tl::make_unexpected(eError::JSON_PARSE_ERROR);
+    payload.serial      = *id;
     return payload;
   }
 }
@@ -392,7 +428,10 @@ RequestResume::from_string(const std::string &str) {
   } else {
     RequestResume r;
     r.message_reference = json["message_reference"].u();
-    r.transaction_reference = json["transaction_reference"].s();
+    auto tr = BigInt::from_string(json["transaction_reference"].s());
+    if (!tr)
+      return tl::make_unexpected(eError::JSON_PARSE_ERROR);
+    r.transaction_reference = *tr;
     return r;
   }
 }
@@ -462,7 +501,7 @@ public:
 
   const std::vector<MintKeyCert>
   getMKCs(const std::vector<unsigned int> &denominations,
-          const std::vector<unsigned int> &mint_key_ids) override {
+          const std::vector<BigInt> &mint_key_ids) override {
     std::vector<MintKeyCert> res;
     cout << __FUNCTION__ << endl;
     return res;

src/model.hpp

@@ -9,10 +9,11 @@
 #include "crow/json.h"
 
 #include "tl/expected.hpp"
+#include "big_int.hpp"
 
 struct PublicKey {
-  std::string modulus; //: "daaa63ddda38c189b8c49020c8276adbe0a695685a...",
+  BigInt modulus; //: "daaa63ddda38c189b8c49020c8276adbe0a695685a...",
-  std::string public_exponent; //: 65537,
+  BigInt public_exponent;//: 65537,
 
   crow::json::wvalue to_json() const;
 };
@@ -35,7 +36,8 @@ struct CDD {
   size_t  currency_divisor;//: 100,
   std::string  currency_name;//: OpenCent,
   std::vector<unsigned>  denominations;//: [1, 2, 5],
-  std::string id; //: 23ed956e629ba35f0002eaf833ea436aea7db5c2,
+  BigInt id;//: 23ed956e629ba35f0002eaf833ea436aea7db5c2,
+
 std::vector<WeightedUrl> info_service;
   /* eCipherSuite*/ std::string issuer_cipher_suite; //: RSA-SHA256-PSS-CHAUM82,
   PublicKey
@@ -64,8 +66,8 @@ struct MintKey {
   unsigned int cdd_serial;
   std::string coins_expiry_date; //": "2023-10-30T15:45:53.164685",
   unsigned int denomination; //": 1,
-  std::string id;                // "1ceb977bb531c65f133ab8b0d60862b17369d96",
+  BigInt id;   // "1ceb977bb531c65f133ab8b0d60862b17369d96",
-  std::string issuer_id; //": "23ed956e629ba35f0002eaf833ea436aea7db5c2",
+  BigInt issuer_id; //": "23ed956e629ba35f0002eaf833ea436aea7db5c2",
   PublicKey public_mint_key;
 
   std::string sign_coins_not_after;
@@ -128,7 +130,7 @@ struct RequestMKCs {
   std::vector<unsigned int> denominations;
   unsigned int message_reference; /// Client internal message reference.
                                   /// (Integer)
-  std::vector<unsigned int> mint_key_ids;
+  std::vector<BigInt> mint_key_ids;
   //  "type": "request mint key certificates"
   static tl::expected<RequestMKCs, eError> from_string(const std::string &str);
 };
@@ -140,15 +142,15 @@ struct ResponseMKCs : Response {
 };
 
 struct Blind {
-  std::string blinded_payload_hash; // bigint
+  BigInt blinded_payload_hash; //bigint
-  std::string mint_key_id;          // bigint
+  BigInt mint_key_id; //bigint
   std::string reference;
   crow::json::wvalue to_json() const;
   static tl::expected<Blind, eError> from_json(const crow::json::rvalue &json);
 };
 
 struct BlindSignature {
-  std::string blind_signature;
+  BigInt blind_signature;
   std::string reference;
   crow::json::wvalue to_json() const;
 };
@@ -156,7 +158,7 @@ struct BlindSignature {
 struct RequestMint {
   unsigned int message_reference; /// Client internal message reference.
                                   /// (Integer)
-  std::string transaction_reference;
+  BigInt transaction_reference; 
   std::vector<Blind> blinds;
   //  "type": "request mint"
   static tl::expected<RequestMint, eError> from_string(const std::string &str);
@@ -172,14 +174,13 @@ struct Coin {
   struct Payload {
     std::string cdd_location;
     unsigned int denomination;
-    std::string issuer_id;
+    BigInt issuer_id;
-    std::string mint_key_id;
+    BigInt mint_key_id;
     std::string protocol_version;
-    std::string serial;
+    BigInt serial;
     
     crow::json::wvalue to_json() const;  
-    static tl::expected<Payload, eError>
+    static tl::expected<Payload,eError> from_json(const crow::json::rvalue& json);
-    from_json(const crow::json::rvalue &json);
   };
 
   Payload payload;
@@ -213,7 +214,7 @@ struct ResponseDelay : Response {
 struct RequestResume {
   unsigned int message_reference; /// Client internal message reference.
                                   /// (Integer)
-  std::string transaction_reference;
+  BigInt transaction_reference; 
   //  "type": "request resume"
   static tl::expected<RequestResume, eError>
   from_string(const std::string &str);
@@ -241,10 +242,10 @@ public:
 
   virtual const std::vector<MintKeyCert>
   getMKCs(const std::vector<unsigned int> &denominations,
-          const std::vector<unsigned int> &mint_key_ids) = 0;
+          const std::vector<BigInt> &mint_key_ids) = 0;
 
   virtual std::vector<BlindSignature>
-  mint(const std::string &transaction_reference,
+  mint(std::string const& transaction_reference,
        const std::vector<Blind> &blinds) = 0;
   virtual bool redeem(const std::vector<Coin> &coins) = 0;
 

test/test.cpp

@@ -3,12 +3,14 @@
 #include <catch2/catch_test_macros.hpp>
 
 TEST_CASE( "PublicKey::to_json", "[to_json]" ) {
-  PublicKey k{"daaa63ddda38c189b8c49020c8276adbe0a695685a...", "65537"};
   
+  PublicKey k //{ BigInt::from_string("daaa63ddda38c189b8c49020c8276adbe0a695685a...").value(),
+    //    BigInt::from_int(65537UL) };
+    ;
   auto json = k.to_json();
 
-  REQUIRE(json["modulus"].dump() == "\"" + k.modulus + "\"");
+  REQUIRE( json["modulus"].dump() == "\"" + k.modulus.to_string() + "\""  );
-  REQUIRE(json["public_exponent"].dump() == "\"" + k.public_exponent + "\"");
+  REQUIRE( json["public_exponent"].dump() == "\"" + k.public_exponent.to_string()+"\"" );
   REQUIRE( json["type"].dump() == "\"rsa public key\"" );
   REQUIRE( json.keys().size() == 3 );
 }
@@ -76,15 +78,14 @@ TEST_CASE("RequestCDDC::from_string", "[from_string]") {
 
 TEST_CASE("RequestMKCs::from_string", "[from_string]") {
   // good case
-  auto res =
+  auto res = RequestMKCs::from_string( "{"
-      RequestMKCs::from_string("{"
 				       "\"denominations\": [1, 2, 5],"
 				       "\"message_reference\": 100002,"
 				       "\"mint_key_ids\": [],"
 				       "\"type\": \"request mint key certificates\""
 				       "}");
   const std::vector<uint32_t> EXPECTED_DENOMINATIONS = {1,2,5};
-  const std::vector<uint32_t> EXPECTED_MINT_KEY_IDS = {};
+  const std::vector<BigInt> EXPECTED_MINT_KEY_IDS = {};
 
   REQUIRE(res.has_value() == true);
   REQUIRE(res->denominations == EXPECTED_DENOMINATIONS);
@@ -137,14 +138,14 @@ TEST_CASE("Blind::from_json", "[from_string]") {
 
   auto res = Blind::from_json(good);
   REQUIRE(res.has_value()==true);
-  REQUIRE(res->blinded_payload_hash ==
+  REQUIRE(res->blinded_payload_hash.to_string()==
 	  "924edb672c3345492f38341ff86b57181da4c673ef...");
-  REQUIRE(res->mint_key_id == "1ceb977bb531c65f133ab8b0d60862b17369d96");
+  REQUIRE(res->mint_key_id.to_string()=="1ceb977bb531c65f133ab8b0d60862b17369d96");
   REQUIRE(res->reference=="a0");
   // bad cases 
-  // wrong_type["blinded_payload_hash"]=
+  // wrong_type["blinded_payload_hash"]= "924edb672c3345492f38341ff86b57181da4c673ef...";
-  // "924edb672c3345492f38341ff86b57181da4c673ef..."; wrong_type["mint_key_id"]=
+  // wrong_type["mint_key_id"]= "1ceb977bb531c65f133ab8b0d60862b17369d96";
-  // "1ceb977bb531c65f133ab8b0d60862b17369d96"; wrong_type["reference"] = "a0";
+  // wrong_type["reference"] = "a0";
   // wrong_type["type"]= "wrong type";
 
   // res = Blind::from_json(wrong_type);
@@ -152,26 +153,22 @@ TEST_CASE("Blind::from_json", "[from_string]") {
 
 TEST_CASE("RequestMint::from_string", "[from_string]") {
   // good case
-  auto res = RequestMint::from_string(
+  auto res = RequestMint::from_string( "{"
-      "{"
 				       "\"blinds\": ["
 				       "{"
-      "\"blinded_payload_hash\": "
+				       "\"blinded_payload_hash\": \"924edb672c3345492f38341ff86b57181da4c673ef...\","
-      "\"924edb672c3345492f38341ff86b57181da4c673ef...\","
 				       "\"mint_key_id\": \"1ceb977bb531c65f133ab8b0d60862b17369d96\","
 				       "\"reference\": \"a0\","
 				       "\"type\": \"blinded payload hash\""
 				       "},"
 				       "{"
-      "\"blinded_payload_hash\": "
+				       "\"blinded_payload_hash\": \"95db92e1c46ebea5edec5e508a831263de6fb78b4c...\","
-      "\"95db92e1c46ebea5edec5e508a831263de6fb78b4c...\","
 				       "\"mint_key_id\": \"f2864e5cd937dbaa4825e73a81062de162143682\","
 				       "\"reference\": \"a1\","
 				       "\"type\": \"blinded payload hash\""
 				       "},"
 				       "{"
-      "\"blinded_payload_hash\": "
+				       "\"blinded_payload_hash\": \"10afac98ac43eb40e996c621d5db4d2238348e3f74...\","
-      "\"10afac98ac43eb40e996c621d5db4d2238348e3f74...\","
 				       "\"mint_key_id\": \"897a16bf12bd9ba474ef7be0e3a53553a7b4ece8\","
 				       "\"reference\": \"a2\","
 				       "\"type\": \"blinded payload hash\""
@@ -184,7 +181,7 @@ TEST_CASE("RequestMint::from_string", "[from_string]") {
 
   REQUIRE(res.has_value()==true);
   REQUIRE(res->message_reference==100003);
-  REQUIRE(res->transaction_reference == "b2221a58008a05a6c4647159c324c985");
+  REQUIRE(res->transaction_reference.to_string() == "b2221a58008a05a6c4647159c324c985");
   /// \todo check blinds
 
   // bad cases
@@ -280,8 +277,7 @@ TEST_CASE("RequestRenew::from_string", "[from_string]") {
 
 TEST_CASE("RequestResume::from_string", "[from_string]") {
   // good case
-  auto res = RequestResume::from_string(
+  auto res = RequestResume::from_string( "{"
-      "{"
 				       "\"message_reference\": 100005,"
 				       "\"transaction_reference\": \"ad45f23d3b1a11df587fd2803bab6c39\","
 				       "\"type\": \"request resume\""
@@ -289,7 +285,7 @@ TEST_CASE("RequestResume::from_string", "[from_string]") {
 
   REQUIRE(res.has_value()==true);
   REQUIRE(res->message_reference==100005);
-  REQUIRE(res->transaction_reference == "ad45f23d3b1a11df587fd2803bab6c39");
+  REQUIRE(res->transaction_reference.to_string()=="ad45f23d3b1a11df587fd2803bab6c39");
   
   // bad cases
   res = RequestResume::from_string("");

test/test_big_int.cpp

@@ -0,0 +1,17 @@
+#include "big_int.hpp"
+#include <catch2/catch_test_macros.hpp>
+
+TEST_CASE("BigInt::from_string", "[big_int]") {
+  auto valid_hex = "aabbcc";
+  {
+    auto b = BigInt::from_string(valid_hex);
+    REQUIRE(b.has_value());
+
+    REQUIRE(b->data == valid_hex);
+  }
+}
+
+TEST_CASE("BigInt::from_int", "[big_int]") {
+  auto b = BigInt::from_int(0xaabbcc);
+  REQUIRE(b.data=="aabbcc");
+}