Solution: add a crypto [de-]initialiser, refcounted and serialised
through critical sections.
This is necessary as utility APIs such as zmq_curve_keypair also
call into the sodium/tweetnacl libraries and need the initialisation
outside of the zmq context.
Also the libsodium documentation explicitly says that sodium_init
must not be called concurrently from multiple threads, which could
have happened until now. Also the randombytes_close function does
not appear to be thread safe either.
This change guarantees that the library is initialised only once at
any given time across the whole program.
Fixes#2632
libzmq used to switch off pedantic checks when using tweetnacl. As
this is now the default, that means pedantic checks are always off.
This is not good.
Solution: in tweetnacl.c alone, use a GCC pragma to disable sign
comparison warnings. We could also clean the code up yet this is
simpler. In other code, we still want those warnings, hence I've
used a pragma rather than global compile option.
Second, use -Wno-long-long all the time, as this warning does not
work with a pragma.
I removed code that set -wno-long-long, for MinGW and Solaris.
Related problem 2: --with-relaxed is badly named
This option switches off pedantic checks, so should be called
--disable-pedantic. 'with' is for optional packages.
- they have no copyright / license statement
- they are in some randomish directory structure
- they are a mix of postable and non-portable files
- they do not conform to conditional compile environment
Overall, it makes it rather more work than needed, in build scripts.
Solution: clean up tweetnacl sauce.
- merged code into single tweetnacl.c and .h
- standard copyright header, DJB to AUTHORS
- moved into src/ along with all other source files
- all system and conditional compilation hidden in these files
- thus, they can be compiled and packaged in all cases
- ZMQ_USE_TWEETNACL is set when we're using built-in tweetnacl
- HAVE_LIBSODIUM is set when we're using external libsodium
