Heimdal's ASN.1 compiler generates code that allows specially
crafted DER encodings of CHOICEs to invoke the wrong free function
on the decoded structure upon decode error. This is known to impact
the Heimdal KDC, leading to an invalid free() of an address partly
or wholly under the control of the attacker, in turn leading to a
potential remote code execution (RCE) vulnerability.
This error affects the DER codec for all CHOICE types used in
Heimdal, though not all cases will be exploitable. We have not
completed a thorough analysis of all the Heimdal components
affected, thus the Kerberos client, the X.509 library, and other
parts, may be affected as well.
This bug has been in Heimdal since 2005. It was first reported by
Douglas Bagnall, though it had been found independently by the
Heimdal maintainers via fuzzing a few weeks earlier.
Apple clang version 14.0.0 (clang-1400.0.17.3.1) fails the build
because stds.h defines `fallthrough` as a macro which is then
expanded when base.h evaluates
# if __has_attribute(fallthrough) && __clang_major__ >= 5
The macOS SDK defines `DISPATCH_FALLTHROUGH` as the macro instead
of `fallthrough`.
This change replaces the use of `fallthrough` in the tree with
`HEIM_FALLTHROUGH` and updates the declaration in configure logic
to define `HEIM_FALLTHROUGH` based upon existing definitions
(if any) of `fallthrough` or `DISPATCH_FALLTHROUGH`.
Do not leak the object when the intent is to free it.
Introduced by 40d1271094
("asn1: Expand decoration w/ C types")
Change-Id: If8cd502f61d6f9b72118630839525933911c6697
The pseudo keyword 'fallthrough' is defined such that case statement
blocks must end with any of these keywords:
* break;
* fallthrough;
* continue;
* goto <label>;
* return [expression];
*
* gcc: https://gcc.gnu.org/onlinedocs/gcc/Statement-Attributes.html#Statement-Attributes
The macro is defined either as
__attribute__((__fallthrough__))
or as
do {} while (0) /* fallthrough */
not including the semicolon.
This change implements the Linux kernel style and updates several locations
where "/*fallthrough*/ and /* FALLTHROUGH */ were not previously replaced.
Externally imported code such as libedit, libtommath and sqlite are
restored to their unaltered state.
Change-Id: I69db8167b0d5884f55d96d72de3059a0235a1ba3
This commits allows `heim_object_t` as a type and causes the generated
code to use the `heim_retain()` and `heim_release()` functions for
copying and releasing values of such types.
Also, now one can have more than one decoration per-type.
This adds support for asn1_compile --decorate=... variation that causes
decoration of an ASN.1 SET/SEQUENCE type with a field of a non-ASN.1
type.
This means we can now have an ASN.1 type to represent a request that can
then have a "hidden" field -- hidden in that it is neither encoded nor
decoded. This field will be copied and freed when the decoration is of
an ASN.1 type or of a external, C type that comes with copy constructor
and destructor functions. Decoration with a `void *` field which is
neither copied nor freed is also supported.
We may end up using this to, for example, replace the `hdb_entry_ex`
type by decorating `HDB_entry` with a C type that points to the `HDB` in
which the entry was found or to which it should be written.
This option, `--decorate=TYPE-NAME:FIELD-TYPE:field-name[?]` allows one to add
a field to any struct generated by the ASN.1 compiler for any SET or SEQUENCE
type such that:
- the field will be freed by the `free_TYPE_NAME()` function
- the field will be copied by the `copy_TYPE_NAME()` function
- the field will not be printed by the `print_TYPE_NAME()` function
- the field will NOT be encoded or decoded
This is useful for internal bookkeeping.
The first use of this may well be for adding an optional field to
`Principal` where information about name attributes will be stored,
which will then allow us to have GSS name attributes for the krb5
mechanism w/o having to refactor the mechanism to use a different
structure for representing `gss_name_t` mechnames than the one currently
used (`Principal`; `krb5_principal` happens to be a typedef alias of
`Principal *`).
So w/o massive rototilling of the GSS krb5 mechanism we can have name
attributes, _and_ we'll also be able to have those in the krb5 API as
well w/o any massive rototilling there either.
Highlighs for the compiler is support for CHOICE and in general better
support for tags. This compiler support most of what is needed for
PK-INIT, LDAP, X.509, PKCS-12 and many other protocols.
git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@15617 ec53bebd-3082-4978-b11e-865c3cabbd6b
