A user reported being confused about the fuid association of subsequent
FTP commands when a data transfer has completed. It seems reasonable to
unset fuid upon logging a FTP command which had a fuid.
The current behavior results in the PORT or PASV commands after a RETR or STOR
to have the fuid of the prior file transfer. Similarly, any CWD or DEL commands
following a file transfer will unnecessarily be logged with the fuid of the
prior file transfer.
This tickles the baselines for the private testing PCAP a lot, primarily
because there data connections in that pcap are never established properly.
E.g, the fuids FzDzid1Dxm9srVKHXf and FEfYX73q5C6GEQZXX9 have been re-used
for multiple commands.
This may look like we're losing information, but the fuids vanishing
in the normal btests belong to a LIST command that isn't logged by
default into ftp.log. If it was, the fuid would be attached to it.
OSS Fuzz generated a CWD request and reply followed by very many EPRT
requests. This caused Zeek to re-log the CWD request and invoke `build_url_ftp()`
over and over again resulting in long processing times.
Avoid this scenario by not logging commands that aren't pending anymore.
(cherry picked from commit b05dd31667ff634ec7d017f09d122f05878fdf65)
This commit switches UID hashing from md5 to a highway hash. It also
moves the salt value out of the file plugin - and makes it
installation-specific instead - it is moved to the global namespace.
There now are digest hash functions to make "static"
installation-specific hashes that are stable over workers available to
everyone; hashes can be 64, 128 or 256 bits in size.
Due to the fact that we switch the file hashing algorithm, all file
hashes change.
The underlyigng algorithm that is used for hashing is highwayhash-128,
which is significantly faster than md5.
The server-reported file size was being collected poorly and if
a file name had a number in it, that was reported as the file
size instead of the actual size.
A new test is included to avoid reintroducing the problem.
