Add support for loading verify and chain stores in SSL_CONF.

Commands to set verify mode and client CA names.

Add documentation.
Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

Reviewed-by: NRich Salz <rsalz@openssl.org>

Given the pervasive nature of TLS extensions it is inadvisable to run
OpenSSL without support for them. It also means that maintaining
the OPENSSL_NO_TLSEXT option within the code is very invasive (and probably
not well tested). Therefore it is being removed.
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Add SSL_use_certiicate_chain file functions: this is works the same
way as SSL_CTX_use_certificate_chain_file but for an SSL structure.

Update SSL_CONF code to use the new function.
Update docs.
Update ordinals.
Reviewed-by: NRich Salz <rsalz@openssl.org>

For the various string-compare routines (strcmp, strcasecmp, str.*cmp)
use "strcmp()==0" instead of "!strcmp()"
Reviewed-by: NTim Hudson <tjh@openssl.org>

Add command line switch entries to table and return SSL_CONF_TYPE_NONE for
them in SSL_CONF_cmd_value_type.

Update docs.
Reviewed-by: NRich Salz <rsalz@openssl.org>

For a local variable:
        TYPE *p;
Allocations like this are "risky":
        p = OPENSSL_malloc(sizeof(TYPE));
if the type of p changes, and the malloc call isn't updated, you
could get memory corruption.  Instead do this:
        p = OPENSSL_malloc(sizeof(*p));
Also fixed a few memset() calls that I noticed while doing this.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Add OSSL_NELEM macro to e_os.h to determine the number of elements in an
array.
Reviewed-by: NTim Hudson <tjh@openssl.org>

Don't check for NULL before calling OPENSSL_free
Reviewed-by: NRichard Levitte <levitte@openssl.org>

This is merges the old "rsalz-monolith" branch over to master.  The biggest
change is that option parsing switch from cascasding 'else if strcmp("-foo")'
to a utility routine and somethin akin to getopt.  Also, an error in the
command line no longer prints the full summary; use -help (or --help :)
for that.  There have been many other changes and code-cleanup, see
bullet list below.

Special thanks to Matt for the long and detailed code review.

TEMPORARY:
        For now, comment out CRYPTO_mem_leaks() at end of main

Tickets closed:
        RT3515: Use 3DES in pkcs12 if built with no-rc2
        RT1766: s_client -reconnect and -starttls broke
        RT2932: Catch write errors
        RT2604: port should be 'unsigned short'
        RT2983: total_bytes undeclared #ifdef RENEG
        RT1523: Add -nocert to fix output in x509 app
        RT3508: Remove unused variable introduced by b09eb246
        RT3511: doc fix; req default serial is random
        RT1325,2973: Add more extensions to c_rehash
        RT2119,3407: Updated to dgst.pod
        RT2379: Additional typo fix
        RT2693: Extra include of string.h
        RT2880: HFS is case-insensitive filenames
        RT3246: req command prints version number wrong

Other changes; incompatibilities marked with *:
        Add SCSV support
        Add -misalign to speed command
        Make dhparam, dsaparam, ecparam, x509 output C in proper style
        Make some internal ocsp.c functions void
        Only display cert usages with -help in verify
        Use global bio_err, remove "BIO*err" parameter from functions
        For filenames, - always means stdin (or stdout as appropriate)
        Add aliases for -des/aes "wrap" ciphers.
        *Remove support for IISSGC (server gated crypto)
        *The undocumented OCSP -header flag is now "-header name=value"
        *Documented the OCSP -header flag
Reviewed-by: NMatt Caswell <matt@openssl.org>

This commit handles BIO_ACCEPT_free BIO_CB_FREE BIO_CONNECT_free
BIO_free BIO_free_all BIO_vfree
Reviewed-by: NMatt Caswell <matt@openssl.org>

Support loading of key and certificate from the same file if
SSL_CONF_FLAG_REQUIRE_PRIVATE is set. This is done by remembering the
filename used for each certificate type and attempting to load a private
key from the file when SSL_CONF_CTX_finish is called.

Update docs.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Start ensuring all OpenSSL "free" routines allow NULL, and remove
any if check before calling them.
This gets DH_free, DSA_free, RSA_free
Reviewed-by: NMatt Caswell <matt@openssl.org>

Suggested by John Foley <foleyj@cisco.com>.
Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NTim Hudson <tjh@openssl.org>

Reviewed-by: NTim Hudson <tjh@openssl.org>

RT#3625
Reviewed-by: NEmilia Käsper <emilia@openssl.org>

The only support for SSLv2 left is receiving a SSLv2 compatible client hello.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

(cherry picked from commit 1f44dac24d1cb752b1a06be9091bb03a88a8598e)

PR#3172

Add -ecdh_single option to set SSL_OP_SINGLE_ECDH_USE on the command line.
(cherry picked from commit f14a4a861d2d221ed565a75441a218f85b8db530)

Extend SSL_CONF to return command value types.

Add certificate and key options.

Update documentation.