libsodium calls abort() when /dev/urandom can't be found
even if one creates ZeroMQ context before calling chroot()[1].
This happens because crypto gets initialized on handshake,
and at that moment the process is already chroot'ed.
Solution: initialize cryptographic libraries in ctx
randombytes_close() is already there in the destructor.
[1] https://download.libsodium.org/doc/usage/index.html
- 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
It's unclear which we need and in the source code, conditional code
treats tweetnacl as a subclass of libsodium, which is inaccurate.
Solution: redesign the configure/cmake API for this:
* tweetnacl is present by default and cannot be enabled
* libsodium can be enabled using --with-libsodium, which replaces
the built-in tweetnacl
* CURVE encryption can be disabled entirely using --enable-curve=no
The macros we define in platform.hpp are:
ZMQ_HAVE_CURVE 1 // When CURVE is enabled
HAVE_LIBSODIUM 1 // When we are using libsodium
HAVE_TWEETNACL 1 // When we're using tweetnacl (default)
As of this patch, the default build of libzmq always has CURVE
security, and always uses tweetnacl.
Of course people still "can" distributed the sources under the
LGPLv3. However we provide COPYING.LESSER with additional grants.
Solution: specify these grants in the header of each source file.
There are two todo comments in curve_client.cpp and curve_server.cpp that suggest
checking the return code of sodium_init() call. sodium_init() returns -1 on error,
0 on success and 1 if it has been called before and is already initalized:
https://github.com/jedisct1/libsodium/blob/master/src/libsodium/sodium/core.c
* The INITIATE command vouch box is Box[C',S](C->S') instead of Box[C'](C->S),
as recommended by https://codesinchaos.wordpress.com/2012/09/09/curvecp-1/,
to reduce the risk of client impersonation.
* Mirrors the change in libcurve and CurveZMQ specifications.
* Command names changed from null terminated to length-specified
* Command frames use the correct flag (bit 2)
* test_stream acts as test case for command frames
* Some code cleanups
- ZMQ_CURVE_PUBLICKEY for clients and servers
- ZMQ_CURVE_SECRETKEY for clients
- ZMQ_CURVE_SERVERKEY for clients
- ZMQ_CURVE_SERVER for servers
- added tools/curve_keygen.c as example
- updated man pages
