situation where they've initialised the ENGINE, loaded keys (which are then
linked to that ENGINE), and performed other checks (such as verifying
certificate chains etc). At that point, if the application goes
multi-threaded or multi-process it creates problems for any ENGINE
implementations that are either not thread/process safe or that perform
optimally when they do not have to perform locking and other contention
management tasks at "run-time".
This defines a new ENGINE_ctrl() command that can be supported by engines
at their discretion. If ENGINE_ctrl(..., ENGINE_CTRL_HUP,...) returns an
error then the caller should check if the *_R_COMMAND_NOT_IMPLEMENTED error
reason was set - it may just be that the engine doesn't support or need the
HUP command, or it could be that the attempted reinitialisation failed. A
crude alternative is to ignore the return value from ENGINE_ctrl() (and
clear any errors with ERR_clear_error()) and perform a test operation
immediately after the "HUP". Very crude indeed.
ENGINEs can support this command to close and reopen connections, files,
handles, or whatever as an alternative to run-time locking when such things
would otherwise be needed. In such a case, it's advisable for the engine
implementations to support locking by default but disable it after the
arrival of a HUP command, or any other indication by the application that
locking is not required. NB: This command exists to allow an ENGINE to
reinitialise without the ENGINE's functional reference count having to sink
down to zero and back up - which is what is normally required for the
finish() and init() handlers to get invoked. It would also be a bad idea
for engine_lib to catch this command itself and interpret it by calling the
engine's init() and finish() handlers directly, because reinitialisation
may need special handling on a case-by-case basis that is distinct from a
finish/init pair - eg. calling a finish() handler may invalidate the state
stored inside individual keys that have already loaded for this engine.
two functions that did expansion on in parameters (BN_mul() and
BN_sqr()). The problem was solved by making bn_dup_expand() which is
a mix of bn_expand2() and BN_dup().
load the "external" built-in engines (those that require DSO). This
makes linking with libdl or other dso libraries non-mandatory.
Change 'openssl engine' accordingly.
Change the engine header files so some declarations (that differed at
that!) aren't duplicated, and make sure engine_int.h includes
engine.h. That way, there should be no way of missing the needed
info.
automatically, however some code was still referring to the original
pointer rather than the internal one (and thus to NULL instead of the
created pointer).
translate library names by only adding ".so" to them without
prepending them with "lib". Add the flag DSO_FLAG_NAME_TRANSLATION_EXT_ONLY
for that purpose.
appropriate filename translation on the host system. Apart from this point,
users should also note that there's a slight change in the API functions
too. The DSO now contains its own to-be-converted filename
("dso->filename"), and at the time the DSO loads the "dso->loaded_filename"
value is set to the translated form. As such, this also provides an impicit
way of determining if the DSO is currently loaded or not. Except, perhaps,
VMS .... :-)
The various DSO_METHODs have been updated for this mechanism except VMS
which is deliberately broken for now, Richard is going to look at how to
fit it in (the source comments in there explain "the issue").
Basically, the new callback scheme allows the filename conversion to
(a) be turned off altogether through the use of the
DSO_FLAG_NO_NAME_TRANSLATION flag,
(b) be handled in the default way using the default DSO_METHOD's converter
(c) overriden per-DSO by setting the override callback
(d) a mix of (b) and (c) - eg. implement an override callback that;
(i) checks if we're win32 "if(strstr(dso->meth->name, "win32"))..."
and if so, convert "blah" into "blah32.dll" (the default is
otherwise to make it "blah.dll").
(ii) default to the normal behaviour - eg. we're not on win32, so
finish with (return dso->meth->dso_name_converter(dso,NULL)).
(e) be retried a number of times by writing a new DSO_METHOD where the
"dso_load()" handler will call the converter repeatedly. Then the
custom converter could use state information in the DSO to suggest
different conversions or paths each time it is invoked.
