Don't dump core in ssltest.

First tentative impementation of Kerberos 5 cryptos and keys for SSL/TLS.  Implemented by Vern Staats <staatsvr@asc.hpc.mil>, further hacked and distributed by Jeffrey Altman <jaltnab@columbia.edu>

violation in test_kron on a 32 bit system.

But even if this is avoided, there are still segmentation violations
(during one of the BN_free()s at the end of test_kron
in some cases, in other cases during BN_kronecker, or
later in BN_sqrt; choosing a different exponentiation
algorithm in bntest.c appears to influence when the SIGSEGV
takes place).

Submitted by: Lenka Fibikova

types of questions.  Hopefully, that'll make them easier to spot, and
specially, easier to refer to.

generated errors.  Therefore, print whatever error there may be...

free that, since it's shared by all SSL_CTX's, present and future.

systems where such an operation is supported.

Windows.  Really, this should probably be done on Unix as well, but
that will be a later story...

Fix BN_mod_exp_simple for a==0 (mod m).
Skip useless round in BN_mod_sqrt (1 is always a square, no need
to test BN_kronecker for it).

  tunnel to not pro-actively close down when failing an SSL handshake.

* Change the cert-chain callback - originally this was the same one used in
  s_client and s_server but the output's as ugly as sin, so I've prettied
  tunala's copy output up a bit (and made the output level configurable).

* Remove the superfluous "errors" from the SSL state callback - these are just
  non-blocking side-effects.

exists in bn_sqrt.c now

test_bn still fails in the BN_sqrt test because
small primes appear to turn into zero for no
obvious reason, leading to "div by zero" errors.

are not reduced modulo m, the outputs won't be either).

similarly modified now on DH and DSA.

the initialisation and cleanup of "ex_data" elements to before an init()
handler and after a finish() handler respectively.

(we need the two's complement of BN_lsw then).

* A little bit of code-cleanup
* Reformat the usage string (not so wide)
* Allow adding an alternative (usually DSA) cert/key pair (a la s_server)
* Allow control over cert-chain verify depth

so we have to reduce the random numbers used in test_mont.

Before this change, test_mont failed in [debug-]solaris-sparcv9-gcc
configurations ("Montgomery multiplication test failed!" because
the multiplication result obtained with Montgomery multiplication
differed from the result obtained by BN_mod_mul).
Substituing the old version of bn_gcd.c (BN_mod_inverse) did not avoid
the problem.

The strange thing is that it I did not observe any problems
when using debug-solaris-sparcv8-gcc and solaris-sparcv9-cc,
as well as when compiling OpenSSL 0.9.6 in the solaric-sparcv9-gcc
configuration on the same system.

For the server side this was already done one year ago :-(

Improve readability of bn_shift.c.

Add comment in bn_lib.c (why zero data between top and max?)

Change bntest.c output for BN_kronecker test