This flag was not set anywhere within the codebase (only read). It could
only be set by an app reaching directly into s->s3->flags and setting it
directly. However that method became impossible when libssl was opaquified.

Even in 1.0.2/1.0.1 if an app set the flag directly it is only relevant to
ssl3_connect(), which calls SSL_clear() during initialisation that clears
any flag settings. Therefore it could take effect if the app set the flag
after the handshake has started but before it completed. It seems quite
unlikely that any apps really do this (especially as it is completely
undocumented).

The purpose of the flag is suppress flushing of the write bio on the client
side at the end of the handshake after the client has written the Finished
message whilst resuming a session. This enables the client to send
application data as part of the same flight as the Finished message.

This flag also controls the setting of a second flag SSL3_FLAGS_POP_BUFFER.
There is an interesting comment in the code about this second flag in the
implementation of ssl3_write:

	/* This is an experimental flag that sends the
	 * last handshake message in the same packet as the first
	 * use data - used to see if it helps the TCP protocol during
	 * session-id reuse */

It seems the experiment did not work because as far as I can tell nothing
is using this code. The above comment has been in the code since SSLeay.

This commit removes support for SSL3_FLAGS_DELAY_CLIENT_FINISHED, as well
as the associated SSL3_FLAGS_POP_BUFFER.
Reviewed-by: NRich Salz <rsalz@openssl.org>

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

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

Create bn_free_d utility routine and use it.
Fix RT3950
Also a missing cleanse, from Loganaden Velvindron (loganaden@gmail.com),
who noticed it in a Cloudflare patch.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NKurt Roeckx <kurt@openssl.org>

Reviewed-by: NKurt Roeckx <kurt@openssl.org>

Use new SSL_CONF options in demo. Add intermediate and root CAs and
update all to use SHA256.
Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

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>

Removed ability to set ex_data impl at runtime.  This removed these
three functions:
    const CRYPTO_EX_DATA_IMPL *CRYPTO_get_ex_data_implementation(void);
    int CRYPTO_set_ex_data_implementation(const CRYPTO_EX_DATA_IMPL *i);
    int CRYPTO_ex_data_new_class(void);
It is no longer possible to change the ex_data implementation at
runtime.  (Luckily those functions were never documented :)

Also removed the ability to add new exdata "classes."  We don't believe
this received much (if any) use, since you can't add it to OpenSSL objects,
and there are probably better (native) methods for developers to add
their own extensible data, if they really need that.

Replaced the internal hash table (of per-"class" stacks) with a simple
indexed array.  Reserved an index for "app" application.

Each API used to take the lock twice; now it only locks once.

Use local stack storage for function pointers, rather than malloc,
if possible (i.e., number of ex_data items is under a dozen).

Make CRYPTO_EX_DATA_FUNCS opaque/internal.

Also fixes RT3710; index zero is reserved.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

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

Remove support for RSA_NET and Netscape key format (-keyform n).

Also removed documentation of SGC.
Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

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

This reverts commit e5c0bc6c.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

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

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

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

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

This leaves behind files with names ending with '.iso-8859-1'.  These
should be safe to remove.  If something went wrong when re-encoding,
there will be some files with names ending with '.utf8' left behind.
Reviewed-by: NRich Salz <rsalz@openssl.org>

This requires 'iconv' and that 'file' can take the options '-b' and '-i'.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Fixes GH#330
Reviewed-by: NRich Salz <rsalz@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>

Instead of piping through tardy, and possibly suffering from bugs in certain
versions, use --transform, --owner and --group directly with GNU tar (we
already expect that tar variant).
Reviewed-by: NRich Salz <rsalz@openssl.org>

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

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

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

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

Reviewed-by: NStephen Henson <steve@openssl.org>

Reviewed-by: NStephen Henson <steve@openssl.org>

The -show_chain flag to the verify command line app shows information about
the chain that has been built. This commit adds the text "untrusted" against
those certificates that have been used from the untrusted list.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Fills in the help text for a number of options to verify that were blank.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Fills in a couple of verify options that were lacking documentation.
Reviewed-by: NRich Salz <rsalz@openssl.org>

The function X509_verify_cert checks the value of |ctx->chain| at the
beginning, and if it is NULL then it initialises it, along with the value
of ctx->untrusted. The normal way to use X509_verify_cert() is to first
call X509_STORE_CTX_init(); then set up various parameters etc; then call
X509_verify_cert(); then check the results; and finally call
X509_STORE_CTX_cleanup(). The initial call to X509_STORE_CTX_init() sets
|ctx->chain| to NULL. The only place in the OpenSSL codebase  where
|ctx->chain| is set to anything other than a non NULL value is in
X509_verify_cert itself. Therefore the only ways that |ctx->chain| could be
non NULL on entry to X509_verify_cert is if one of the following occurs:
1) An application calls X509_verify_cert() twice without re-initialising
in between.
2) An application reaches inside the X509_STORE_CTX structure and changes
the value of |ctx->chain| directly.

With regards to the second of these, we should discount this - it should
not be supported to allow this.

With regards to the first of these, the documentation is not exactly
crystal clear, but the implication is that you must call
X509_STORE_CTX_init() before each call to X509_verify_cert(). If you fail
to do this then, at best, the results would be undefined.

Calling X509_verify_cert() with |ctx->chain| set to a non NULL value is
likely to have unexpected results, and could be dangerous. This commit
changes the behaviour of X509_verify_cert() so that it causes an error if
|ctx->chain| is anything other than NULL (because this indicates that we
have not been initialised properly). It also clarifies the associated
documentation. This is a follow up commit to CVE-2015-1793.
Reviewed-by: NStephen Henson <steve@openssl.org>

This adds a test for CVE-2015-1793. This adds a new test file
verify_extra_test.c, which could form the basis for additional
verification tests.
Reviewed-by: NStephen Henson <steve@openssl.org>

During certificate verfification, OpenSSL will attempt to find an
alternative certificate chain if the first attempt to build such a chain
fails. An error in the implementation of this logic can mean that an
attacker could cause certain checks on untrusted certificates to be
bypassed, such as the CA flag, enabling them to use a valid leaf
certificate to act as a CA and "issue" an invalid certificate.

This occurs where at least one cert is added to the first chain from the
trust store, but that chain still ends up being untrusted. In that case
ctx->last_untrusted is decremented in error.

Patch provided by the BoringSSL project.

CVE-2015-1793
Reviewed-by: NStephen Henson <steve@openssl.org>

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

There's no reason why we should default to a output format that is
old, and confusing in some cases.

This affects the commands "ca", "crl", "req" and "x509".
Reviewed-by: NRich Salz <rsalz@openssl.org>

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

In CCM mode don't require a tag before initialising decrypt: this allows
the tag length to be set without requiring the tag.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>