[back-port from HEAD branch]

'OpenSSL_0_9_7-stable'.

listed on the web site for easy finding and downloading

check_ca(), to resolve constness issue.  check_ca() is called from the
purpose checkers instead of X509_check_ca(), since the stuff done by
the latter (except for calling check_ca()) is also done by
X509_check_purpose().

check_ca(), to resolve constness issue.  check_ca() is called from the
purpose checkers instead of X509_check_ca(), since the stuff done by
the latter (except for calling check_ca()) is also done by
X509_check_purpose().

CA setting in each certificate on the chain is correct.  As a side-
effect always do the following basic checks on extensions, not just
when there's an associated purpose to the check:
- if there is an unhandled critical extension (unless the user has
  chosen to ignore this fault)
- if the path length has been exceeded (if one is set at all)
- that certain extensions fit the associated purpose (if one has been
  given)

CA setting in each certificate on the chain is correct.  As a side-
effect always do the following basic checks on extensions, not just
when there's an associated purpose to the check:
- if there is an unhandled critical extension (unless the user has
  chosen to ignore this fault)
- if the path length has been exceeded (if one is set at all)
- that certain extensions fit the associated purpose (if one has been
  given)

leak on VMS.

'OpenSSL_0_9_7-stable'.