Solution: change setsockopts on printable keys to expect 41, nor 40
bytes. Code still accepts 40 bytes for compatibility, and copies the
key to a well-terminated string before using it.
Fixes#1148
This is still raw and experimental.
To connect through a SOCKS proxy, set ZMQ_SOCKS_PROXY socket option on
socket before issuing a connect call, e.g.:
zmq_setsockopt (s, ZMQ_SOCKS_PROXY,
"127.0.0.1:22222", strlen ("127.0.0.1:22222"));
zmq_connect (s, "tcp://127.0.0.1:5555");
Known limitations:
- only SOCKS version 5 supported
- authentication not supported
- new option is still undocumented
Solution: use same approach as for libsodium/CURVE, i.e. return EINVAL
if the library isn't present when libzmq builds, and the application
still tries to use these options in zmq_getsockopt/setsockopt.
The example is applications passing invalid arguments to a socket option
and then failing to check the return code. The results can be very hard
to diagnose. Here are some threads that show the pain this causes:
* https://github.com/zeromq/zyre/issues/179
* http://lists.zeromq.org/pipermail/zeromq-dev/2014-June/026388.html
One common argument is that a library should never assert, and should
pass errors back to the calling application. The counter argument is
that when an application is broken enough to pass garbage to libzmq,
it cannot be trusted to handle the resulting errors properly. Empirical
evidence from CZMQ, where we systematically assert on bad arguments, is
that this militant approach makes applications more, not less, robust.
I don't see any valid use cases for returning errors on bad arguments,
with one exception: zmq_setsockopt can be used to probe whether libzmq
was e.g. built with CURVE security. I'd argue that it's nasty to use a
side effect like this. If apps need to probe how libzmq was built, this
should be done explicitly, and for ALL build options, not just CURVE.
There are/were no libzmq test cases that check the return code for an
invalid option.
For now I've enabled militant assertions using --with-militant at
configure time. However I'd like to make this the default setting.
Applications that use ZMQ_IDENTITY can be trapped by the artificial
restriction on not using a binary zero as first byte. It's specially
nasty on random generated identities, e.g. UUIDs, as the chance of a
binary zero is low, so it will pass 255 out of 256 times.
Solution: remove the restriction.
- This seems redundant; is there a use case for NOT providing
the IPC credentials to the ZAP authenticator?
- More, why is IPC authentication done via libzmq instead of ZAP?
Is it because we're missing the transport type on the ZAP request?
Another take on LIBZMQ-568 to allow filtering IPC connections, this time
using ZAP. This change is backward compatible. If the
ZMQ_ZAP_IPC_CREDS option is set, the user, group, and process IDs of the
peer process are appended to the address (separated by colons) of a ZAP
request; otherwise, nothing changes. See LIBZMQ-568 and zmq_setsockopt
documentation for more information.
* Removed redundant Z85 code and include files from project
* Simplified use of headers in test cases (now they all just use testutil.hpp)
* Export zmq_z85_encode() and zmq_z85_decode() in API
* Added man pages for these two functions
On ZMQ_CURVE_xxxKEY fetches, would return 41 bytes into caller's 40-byte
buffer. Now these fetches only return 41 bytes if the caller explicitly
provides a 41-byte buffer (i.e. the option size is 41).
* This is passed to the ZAP handler in the 'domain' field
* If not set, or empty, then NULL security does not call the ZAP handler
* This resolves the phantom ZAP request syndrome seen with sockets where
security was never intended (e.g. in test cases)
* This means if you install a ZAP handler, it will not get any requests
for new connections until you take some explicit action, which can be
setting a username/password for PLAIN, a key for CURVE, or the domain
for NULL.
These were exposed to users, but have subsequently been removed as
sockopts. They are currently only being used by ZAP, so I've moved it to
a simpl function call (actually it's only used in one case even in that,
so there may be a further simplification possible there).
The use of binary for CURVE keys is painful; you cannot easily copy
these in e.g. email, or use them directly in source code. There are
various encoding possibilities. Base16 and Base64 are not optimal.
Ascii85 is not safe for source (it generates quotes and escapes).
So, I've designed a new Base85 encoding, Z85, which is safe to use
in code and elsewhere, and I've modified libzmq to use this where
it also uses binary keys (in get/setsockopt).
Very simply, if you use a 32-byte value, it's Base256 (binary),
and if you use a 40-byte value, it's Base85 (Z85).
I've put the Z85 codec into z85_codec.hpp, it's not elegant C++
but it is minimal and it works. Feel free to rewrap as a real class
if this annoys you.
- 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
- we need to switch to PLAIN according to options.mechanism
- we need to catch case when both peers are as-server (or neither is)
- and to use username/password from options, for client
* ZMQ_PLAIN_SERVER, ZMQ_PLAIN_USERNAME, ZMQ_PLAIN_PASSWORD options
* Man page changes to zmq_setsockopt and zmq_getsockopt
* Man pages for ZMQ_NULL, ZMQ_PLAIN, and ZMQ_CURVE
* Test program test_security
