Although not required to address bad code generation in
some versions of gcc 9 and 10, a coding style that requires
explicit comparison of the result to zero before use is
both clearer and would have avoided the generation of bad
code.
This change converts all use of cmp function usage from
```
if (strcmp(a, b) || !strcmp(c, d)) ...
```
to
```
if (strcmp(a, b) != 0 || strcmp(c, d)) == 0
```
for all C library cmp functions and related:
- strcmp(), strncmp()
- strcasecmp(), strncasecmp()
- stricmp(), strnicmp()
- memcmp()
Change-Id: Ic60c15e1e3a07e4faaf10648eefe3adae2543188
Anonymous names should always compare FALSE in GSS_Compare_name(). If the names
are being compared at the mechglue layer then we should check for
GSS_C_NT_ANONYMOUS.
The GSS mechglue uses singly linked lists for mechanisms and mechanism objects,
to which new entries are inserted at the head. This breaks ordering of
mechanisms specified in OID sets and in /etc/gss/mech, as they will be back to
front. Use a tail queue instead so that new entries are inserted at the end.
* check `ctx->gc_ctx` in `gss_inquire_context()`
* check `gm_inquire_cred != NULL` in `gss_inquire_context()`
* check `min_lifetime` in `gss_inquire_cred()`
* check `gm_inquire_cred_by_mech != NULL` in `gss_inquire_cred_by_mech()`
* set mech error in `gss_inquire_cred_by_oid()`
* don't clobber error in `gss_inquire_cred_by_oid()`
* don't pass NULL minor_status to `gss_krb5_free_lucid_sec_context()`
* allow NULL ccache in `gss_krb5_ccache_name()`
* NULL names OK in `_gss_find_mn()`
* allow empty names in `gss_import_name()` (removes `input_name_buffer` length
check). to support ANONYMOUS. in `gss_import_name()`, ignore mech name
import failure as long as it's possible to import the name in some other
mechanism
* better argument validation in `gss_export_sec_context()`
* in `gss_compare_name()`, check `mn2 != NULL`
* check `gss_add_oid_set_member()` return code in `gss_indicate_mechs()`
* in `gss_destroy_cred()`, set output cred handle to `GSS_C_NO_CREDENTIAL`
* cast size_t to OM_uint32 where required
In the case that one name has no MNs and the second name only has an MN, then
the order in which the two names are passed in matters, but it shouldn't. Run
the comparison both ways.
Make memcmp() compare the name1 and name2 value instead of comparing
name1 with itself.
The memcmp() is only executed if the left-hand side of the || is false
i.e. when both length are equal so the length argument is correct (no out-of-bounds reads).
