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

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

If something was "present in all versions" of SSLeay, or if it was
added to a version of SSLeay (and therefore predates OpenSSL),
remove mention of it.  Documentation history now starts with OpenSSL.

Remove mention of all history before OpenSSL 0.9.8, inclusive.

Remove all AUTHOR sections.
Reviewed-by: NTim Hudson <tjh@openssl.org>

L<foo|foo> is sub-optimal  If the xref is the same as the title,
which is what we do, then you only need L<foo>.  This fixes all
1457 occurrences in 349 files.  Approximately.  (And pod used to
need both.)
Reviewed-by: NRichard Levitte <levitte@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>

Signed-off-by: NRich Salz <rsalz@akamai.com>
Reviewed-by: NTim Hudson <tjh@openssl.org>