libpcsc-mock

C++ library for mocking responses to PC/SC smart card API function calls. Intended to be used in unit tests to emulate complex PC/SC scenarios like different smart card and reader states and replay of longer APDU request/response sequences.

Overview

Here is a visual overview of the library:

Given the system under test uses the PC/SC API, here is an example Google Test unit test that uses libpcsc-mock to mock the response of the SCardListReaders PC/SC call:

TEST(pcsc_cpp_test, listReadersNoReaders)
{
    PcscMock::addReturnValueForScardFunctionCall("SCardListReaders",
                                                 SCARD_E_NO_READERS_AVAILABLE);

    auto readers = systemUnderTest.listReaders();
    EXPECT_EQ(readers.size(), 0);
}

Here is an example test that uses the replay of longer APDU request/response sequences:

const PcscMock::ApduScript GET_CERTIFICATE {
    // Select master file.
    {{0x00, 0xa4, 0x00, 0x0c}, {0x90, 0x00}},
    // Select directory.
    {{0x00, 0xa4, 0x01, 0x0c, 0x02, 0xee, 0xee}, {0x90, 0x00}},
    // Select certificate file.
    {{0x00, 0xa4, 0x02, 0x0c, 0x02, 0xaa, 0xce}, {0x90, 0x00}},
    ...
};

TEST(electronic_id_test, selectCertificate)
{
    PcscMock::setApduScript(GET_CERTIFICATE);
    auto certificate = systemUnderTest.getCertificate();
    ...
}

You can find more test examples in the libelectronic-id project tests/mock directory.

Building

In Ubuntu:

apt install build-essential pkg-config cmake libgtest-dev valgrind libpcsclite-dev
sudo bash -c 'cd /usr/src/googletest && cmake . && cmake --build . --target install'

cd build
cmake .. # optionally with -DCMAKE_BUILD_TYPE=Debug
cmake --build . # optionally with VERBOSE=1

Testing

Build as described above, then inside build directory:

ctest # or 'valgrind --leak-check=full ctest'

Development guidelines

Format code with scripts/clang-format.sh before committing.