freebsd-skq/kerberos5/lib/libgssapi_krb5/pname_to_uid.c
rmacklem c33ddc827e Fix the getpwnam_r() call in the pname_to_uid() kerberos library function so
that it handles the ERANGE error return case. Without this fix, authentication
of users for certain system setups could fail unexpectedly.

Reported by:	Elias Martenson (lokedhs@gmail.com)
Tested by:	Elias Martenson (earlier version)
MFC after:	2 weeks
2013-05-02 12:52:49 +00:00

84 lines
2.6 KiB
C

/*-
* Copyright (c) 2008 Isilon Inc http://www.isilon.com/
* Authors: Doug Rabson <dfr@rabson.org>
* Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/* $FreeBSD$ */
#include <errno.h>
#include <pwd.h>
#include "krb5/gsskrb5_locl.h"
OM_uint32
_gsskrb5_pname_to_uid(OM_uint32 *minor_status, const gss_name_t pname,
const gss_OID mech, uid_t *uidp)
{
krb5_context context;
krb5_const_principal name = (krb5_const_principal) pname;
krb5_error_code kret;
char lname[MAXLOGNAME + 1], buf[1024], *bufp;
struct passwd pwd, *pw;
size_t buflen;
int error;
OM_uint32 ret;
static size_t buflen_hint = 1024;
GSSAPI_KRB5_INIT (&context);
kret = krb5_aname_to_localname(context, name, sizeof(lname), lname);
if (kret) {
*minor_status = kret;
return (GSS_S_FAILURE);
}
*minor_status = 0;
buflen = buflen_hint;
for (;;) {
pw = NULL;
bufp = buf;
if (buflen > sizeof(buf))
bufp = malloc(buflen);
if (bufp == NULL)
break;
error = getpwnam_r(lname, &pwd, bufp, buflen, &pw);
if (error != ERANGE)
break;
if (buflen > sizeof(buf))
free(bufp);
buflen += 1024;
if (buflen > buflen_hint)
buflen_hint = buflen;
}
if (pw) {
*uidp = pw->pw_uid;
ret = GSS_S_COMPLETE;
} else {
ret = GSS_S_FAILURE;
}
if (bufp != NULL && buflen > sizeof(buf))
free(bufp);
return (ret);
}