Solution: added relicense agreement

Problem: ZAP client code duplicated across mechanisms with behaviour deviations

Problem: missing flags break build of test_security_curve

Solution: replaced unreachable code by assertions and adapted uses

Solution: add testutil_security.hpp to Makefile.am

Solution: added ZAP tests for PLAIN

Solution: added ZAP tests for NULL

Solution: move relevant behavior to zap_client_t

Solution: Move ZAP tests to own file test_security_zap.cpp, move common code to testutil_security.hpp

Solution: as a first step, parametrize mechanism configuration in CURVE tests

Solution: unification, pulled up common behaviour to zap_client_t/zap_client_common_handshake_t

Problem: zap_msg_available duplicated between curve_server_t and plain_server_t (with deviating behaviour)

Solution: pull up into zap_client_common_handshake_t, along with handle_zap_status_code and error_detail/current_error_detail

Solution: extract into new intermediate base class zap_client_common_handshake_t

Solution: pull state enum up to zap_client_t and unify names of enum values

Solution: extract receive_and_process_zap_reply into zap_client_t and convert zap_client_t into base class of the server mechanism classes

Solution: Use zap_client_t::send_zap_request

Solution: Set more flag depending on presence of credentials

Problem: null_mechanism duplicates zap_client_t::send_zap_request\nSolution: use zap_client_t::send_zap_request

Solution: Use zap_client_t::send_zap_request

Solution: created a zap_client_t class, extracted first function send_zap_request from curve_server_t

Solution: add all the required compiler flags since the test includes
source code from the library directly

add missing uint32_t typedef on msvc

uint32_t is used in the draft APIs
and undefined on MSC 1500
preventing compilation

* Problem: no test case with CURVE encryption and large identity

Solution: added test case (currently crashing)

* Problem: possible buffer overflow in mechanism_t::add_property

Solution: add target buffer length parameter and check the buffer is sufficiently large

* Problem: test cases accidentally excluded from build

Solution: remove #if/#endif

* Problem: possible buffer overruns related to metadata at various locations

Solution: allocate buffer large enough for actual metadata, reduce code duplication

* Problem: syntax error related to pointer type conversion

Solution: change argument type of make_command_with_basic_properties to const char *

* Problem: large metadata may cause an assertion in produce_initiate

Solution: Allow metadata of arbitrary size in produce_initiate

* Extracted connect_vanilla_socket function

* Problem: no tests for ZMTP-CURVE protocol errors

Solution: added two test cases with erroneous HELLO commands

* Problem: insufficient tests for ZMTP-CURVE protocol errors

Solution: added two test cases with erroneous HELLO command version

* Problem: test HELLO message is invalid apart from deliberate errors

Solution: create cryptographically correct HELLO message
add tweetnacl.c to test_security_curve

* Problem: nonce is incorrect, build fails with GCC

Solution: use correct non prefix

* Problem: make builds are failing

Solution: transfer CMake changes to (auto)make files

* Problem: nonce is incorrect, build fails with GCC

Solution: use correct non prefix

* Problem: make builds are failing

Solution: transfer CMake changes to (auto)make files

* Problem: no test with INITIATE command with invalid length

Solution: added test case

* Problem: code duplication between test_security_curve.cpp and curve_client.cpp

Solution: extracted parts of zmq::curve_client_t::produce_hello into reusable function

* Problem: code duplication between test_security_curve.cpp and curve_client.cpp

Solution: extracted further parts of zmq::curve_client_t into reusable functions
added missing file

* Problem: mechanism_t::add_property can be declared static

Solution: declare mechanism_t::add_property static

* Problem: intermediate crypto data needs to be passed between static function calls to curve_client_tools_t

Solution: add non-static member functions

* Problem: msg_t instance may be closed twice

Solution: remove offending close

* Problem: prepare_hello uses static curve_client_tools_t::produce_hello

Solution: Use non-static curve_client_tools_t::produce_hello

* Problem: no test with invalid command name where INITIATE command is expected

Solution: added test case

* Problem: make builds are failing due to curve_client_tools.hpp not being found

Solution: add curve_client_tools.hpp to list of source files

* Problem: wrong initializer order in zmq::curve_client_t

Solution: reorder

* Problem: under non-Windows systems, test fails because random_open was not called

Solution: call random_open/random_close within test

* Problem: conflict between custom function htonll and macro definition on Darwin

Solution: define htonll function only if not defined as a macro

* Problem: nullptr not defined on all platforms

Solution: replace nullptr by NULL

* Problem: libsodium builds not working

Solution: adapt compile and link file sets for libsodium builds

* Problem: Makefile.am broken

Solution: Fix syntax

* Problem: no tests for garbage encrypted cookie or content in INITIATE

Solution: added test cases

* Problem: test cases accidentally excluded from build

Solution: remove #if/#endif

* Solution: some error cases are unreachable

Problem: for the time being, added some comments without changing the code

* Added comments on hard-to-test cases

Problem: unused variable causing warnings or breaks.

Problem: unused variables causing warnings or breaks.

Problem SIGBUS under 64-bit SunOS Sparc

Solution: force the compiler to make the atomic_counter_t alignment
friendly.
This will ensure that the pointers inside the buffers allocated by
shared_message_memory are aligned, at the cost of growing the memory
size of atomic_counter_t from 4 to 8 bytes on 64 bit (when not using
mutexes).
Note that although content_t contains an atomic_counter_t, the
compiler already padded the struct so there is no change in the
buffer sizes used by the engines, save for the extra 4 bytes for the
buffer's own single atomic counter.
Fixes #2588

Solution: remove requirement to manually define macro and just check
for the C++ supported version.
Note that compiler intrinsics still have priority if available, to
avoid changes unless necessary.

CURVE throughput performance testing

Solution: Use a double for messages per second and calculate
Megabits per second using it.  Truncate messages per second
only in the reported output.

Solution: Add extra argument to enable CURVE, use
fixed keys to make local_thr and remote_thr compatible
with CURVE enabled.

Problem: CMake build does not allow static linking libsodium

Solution: Pass along SODIUM_STATIC define if set in CMake config

Problem: log for bad ZAP status code is confusing

Solution: log that handler sent bad status code to clarify ZAP debugging