Add curve functions wrappers (#671)

* Add curve functions wrappers

* Add curve CI job and fix the libzmq build

.github/workflows/ci.yml

@@ -16,14 +16,15 @@ jobs:
         cc: ["gcc-10"]
         cxx: ["g++-10"]
         drafts: ["ON"]
+        curve: ["OFF"]
         libzmq: ["4.3.5"]
         libzmqbuild: ["cmake"]
         include:
           # older libzmq and without draft
           - os: "ubuntu-22.04"
             cppstd: "11"
-            cc: "gcc-9"
-            cxx: "g++-9"
+            cc: "gcc-11"
+            cxx: "g++-11"
             drafts: "OFF"
             libzmq: "4.2.0"
             libzmqbuild: "pkgconfig"
@@ -35,12 +36,21 @@ jobs:
             drafts: "OFF"
             libzmq: "4.3.5"
             libzmqbuild: "cmake"
+          # with curve
+          - os: "ubuntu-24.04"
+            cppstd: "23"
+            cc: "gcc-13"
+            cxx: "g++-13"
+            curve: "ON"
+            libzmq: "4.3.5"
+            libzmqbuild: "cmake"
           # coverage (gcc version should match gcov version)
           - os: "ubuntu-22.04"
             cppstd: "17"
-            cc: "gcc-9"
-            cxx: "g++-9"
+            cc: "gcc-11"
+            cxx: "g++-11"
             drafts: "ON"
+            curve: "ON"
             libzmq: "4.3.5"
             libzmqbuild: "cmake"
             coverage: "-DCOVERAGE=ON"
@@ -108,11 +118,17 @@ jobs:
     - name: build_libzmq_cmake
       if: ${{ matrix.libzmqbuild == 'cmake' }}
       run: |
+        if [ ! "${{ matrix.os }}" = 'windows-2022' ]; then
+          export CXXFLAGS="-Wno-error=stringop-truncation -Wno-stringop-overflow"
+          export CFLAGS="-Wno-error=stringop-truncation -Wno-stringop-overflow"
+        fi
         cmake -Hlibzmq-${{ matrix.libzmq }} -Blibzmq-build ${{ matrix.platform}} \
           -DWITH_PERF_TOOL=OFF \
           -DZMQ_BUILD_TESTS=OFF \
+          -DLIBZMQ_WERROR=OFF \
           -DCMAKE_BUILD_TYPE=Release \
-          -DENABLE_DRAFTS=${{ matrix.drafts }}
+          -DENABLE_DRAFTS=${{ matrix.drafts }} \
+          -DENABLE_CURVE=${{ matrix.curve }}
         cmake --build libzmq-build --config ${BUILDTYPE} -j ${THREADS}
         echo "LIBZMQ=${PWD}/libzmq-build" >> ${GITHUB_ENV}
 
@@ -126,6 +142,8 @@ jobs:
       if: ${{ matrix.libzmqbuild == 'pkgconfig' }}
       working-directory: libzmq-${{ matrix.libzmq }}
       run: |
+        export CXXFLAGS="-Wno-error=stringop-truncation -Wno-stringop-overflow"
+        export CFLAGS="-Wno-error=stringop-truncation -Wno-stringop-overflow"
         ./autogen.sh &&
         ./configure --prefix=${PWD}/libzmq-build &&
         make -j ${THREADS}

tests/CMakeLists.txt

@@ -31,6 +31,7 @@ add_executable(
     monitor.cpp
     utilities.cpp
     timers.cpp
+    curve.cpp
 )
 
 target_include_directories(unit_tests PUBLIC ${CATCH_MODULE_PATH})

tests/curve.cpp

@@ -0,0 +1,36 @@
+#include <catch2/catch_all.hpp>
+#include <zmq.hpp>
+
+#ifdef ZMQ_HAVE_CURVE
+
+TEST_CASE("curve_keypair", "[curve]")
+{
+    auto keys = zmq::curve_keypair();
+    auto public_key = keys.first;
+    auto secret_key = keys.second;
+    CHECK(!public_key.empty());
+    CHECK(!secret_key.empty());
+}
+
+TEST_CASE("curve_public", "[curve]")
+{
+    auto secret_key = "D:)Q[IlAW!ahhC2ac:9*A}h:p?([4%wOTJ%JR%cs";
+    auto public_key = zmq::curve_public(secret_key);
+    CHECK(public_key == "Yne@$w-vo<fVvi]a<NY6T1ed:M$fCG*[IaLV{hID");
+}
+
+#endif
+
+TEST_CASE("z85_encode", "[curve]")
+{
+    std::vector<uint8_t> data{1,2,3,4,5,6,7,8};
+    auto encoded = zmq::z85_encode(data);
+    CHECK(encoded.size() == std::string("0rJua1Qkhq").size());
+    CHECK(encoded == "0rJua1Qkhq");
+}
+
+TEST_CASE("z85_decode", "[curve]")
+{
+    auto decoded = zmq::z85_decode("0rJua1Qkhq");
+    CHECK(decoded == std::vector<uint8_t>{1,2,3,4,5,6,7,8});
+}

zmq.hpp

@@ -107,6 +107,7 @@
 
 #include <cassert>
 #include <cstring>
+#include <cstdint>
 
 #include <type_traits>
 #include <algorithm>
@@ -539,7 +540,7 @@ class message_t
             throw error_t();
         memcpy(data(), data_, size_);
     }
-    
+
     void rebuild(const std::string &str)
     {
         rebuild(str.data(), str.size());
@@ -2492,7 +2493,7 @@ class monitor_t
         (void) addr_;
     }
 
-  protected:    
+  protected:
     bool process_event(short events)
     {
         zmq::message_t eventMsg;
@@ -2874,6 +2875,53 @@ class timers
 
 #endif // defined(ZMQ_CPP11) && defined(ZMQ_HAVE_TIMERS)
 
+#ifdef ZMQ_HAVE_CURVE
+
+inline std::pair<std::string, std::string> curve_keypair()
+{
+    char public_key_buffer[41];
+    char secret_key_buffer[41];
+    int rc = zmq_curve_keypair(public_key_buffer, secret_key_buffer);
+    if (rc == -1)
+        throw zmq::error_t();
+    return {public_key_buffer, secret_key_buffer};
+}
+
+inline std::string curve_public(const std::string& secret)
+{
+    if (secret.size() != 40)
+        throw std::runtime_error("Invalid secret string size");
+    char public_key_buffer[41];
+    int rc = zmq_curve_public(public_key_buffer, secret.c_str());
+    if (rc == -1)
+        throw zmq::error_t();
+    return public_key_buffer;
+}
+
+#endif
+
+inline std::string z85_encode(const std::vector<uint8_t>& data)
+{
+    size_t buffer_size = data.size() * size_t{6} / size_t{5} + 1;
+    std::string buffer(buffer_size, '\0');
+    auto *result = zmq_z85_encode(&buffer[0], data.data(), data.size());
+    if (result == nullptr)
+        throw zmq::error_t();
+    while (buffer.back() == '\0')
+        buffer.pop_back();
+    return buffer;
+}
+
+inline std::vector<uint8_t> z85_decode(const std::string& encoded)
+{
+    size_t dest_size = encoded.size() * size_t{4} / size_t{5};
+    std::vector<uint8_t> dest(dest_size);
+    auto *result = zmq_z85_decode(dest.data(), encoded.c_str());
+    if (result == nullptr)
+        throw zmq::error_t();
+    return dest;
+}
+
 } // namespace zmq
 
 #endif // __ZMQ_HPP_INCLUDED__