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Match Heimdal behavior for channel bindings

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This commit is contained in:
Robbie Harwood 2020-06-15 16:57:30 -04:00
parent feaafc07b2
commit e326a52474
12 changed files with 1401 additions and 7 deletions
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419
Add-channel-bindings-tests.patch Normal file
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@ -0,0 +1,419 @@
From 3e92520c1417f22447751cd9172d5ab30c2e0ad8 Mon Sep 17 00:00:00 2001
From: Isaac Boukris <iboukris@gmail.com>
Date: Fri, 20 Mar 2020 00:17:28 +0100
Subject: [PATCH] Add channel bindings tests
[ghudson@mit.edu: adjusted test program to output channel-bound state
instead of optionally enforcing it; adjusted tests to check program
output; split out tests into separate Python script; made cosmetic
changes]
ticket: 8900
(cherry picked from commit b0b21b6d25b06f3e2b365dfe9dd4c99b3d43bf57)
[rharwood@redhat.com: .gitignore]
---
src/plugins/gssapi/negoextest/main.c | 18 +++++
src/tests/gssapi/Makefile.in | 49 ++++++------
src/tests/gssapi/common.c | 25 ++++--
src/tests/gssapi/common.h | 9 +++
src/tests/gssapi/deps | 4 +
src/tests/gssapi/t_bindings.c | 111 +++++++++++++++++++++++++++
src/tests/gssapi/t_bindings.py | 43 +++++++++++
src/tests/gssapi/t_negoex.py | 7 ++
8 files changed, 237 insertions(+), 29 deletions(-)
create mode 100644 src/tests/gssapi/t_bindings.c
create mode 100644 src/tests/gssapi/t_bindings.py
diff --git a/src/plugins/gssapi/negoextest/main.c b/src/plugins/gssapi/negoextest/main.c
index 6c340f41b..72fc5273a 100644
--- a/src/plugins/gssapi/negoextest/main.c
+++ b/src/plugins/gssapi/negoextest/main.c
@@ -57,6 +57,15 @@ gss_init_sec_context(OM_uint32 *minor_status,
const char *envstr;
uint8_t hops, mech_last_octet;
+ envstr = getenv("GSS_INIT_BINDING");
+ if (envstr != NULL) {
+ assert(strlen(envstr) > 0);
+ assert(input_chan_bindings != GSS_C_NO_CHANNEL_BINDINGS);
+ assert(strlen(envstr) == input_chan_bindings->application_data.length);
+ assert(strcmp((char *)input_chan_bindings->application_data.value,
+ envstr) == 0);
+ }
+
if (input_token == GSS_C_NO_BUFFER || input_token->length == 0) {
envstr = getenv("HOPS");
hops = (envstr != NULL) ? atoi(envstr) : 1;
@@ -112,6 +121,15 @@ gss_accept_sec_context(OM_uint32 *minor_status, gss_ctx_id_t *context_handle,
uint8_t hops, mech_last_octet;
const char *envstr;
+ envstr = getenv("GSS_ACCEPT_BINDING");
+ if (envstr != NULL) {
+ assert(strlen(envstr) > 0);
+ assert(input_chan_bindings != GSS_C_NO_CHANNEL_BINDINGS);
+ assert(strlen(envstr) == input_chan_bindings->application_data.length);
+ assert(strcmp((char *)input_chan_bindings->application_data.value,
+ envstr) == 0);
+ }
+
/*
* The unwrapped token sits at the end and is just one byte giving the
* remaining number of hops. The final octet of the mech encoding should
diff --git a/src/tests/gssapi/Makefile.in b/src/tests/gssapi/Makefile.in
index 5cc1e0f58..68c132b79 100644
--- a/src/tests/gssapi/Makefile.in
+++ b/src/tests/gssapi/Makefile.in
@@ -9,33 +9,33 @@ LOCALINCLUDES = -I$(srcdir)/../../lib/gssapi/mechglue \
-I../../lib/gssapi/generic
SRCS= $(srcdir)/ccinit.c $(srcdir)/ccrefresh.c $(srcdir)/common.c \
- $(srcdir)/t_accname.c $(srcdir)/t_add_cred.c $(srcdir)/t_ccselect.c \
- $(srcdir)/t_ciflags.c $(srcdir)/t_context.c $(srcdir)/t_credstore.c \
- $(srcdir)/t_enctypes.c $(srcdir)/t_err.c $(srcdir)/t_export_cred.c \
- $(srcdir)/t_export_name.c $(srcdir)/t_gssexts.c \
- $(srcdir)/t_imp_cred.c $(srcdir)/t_imp_name.c $(srcdir)/t_invalid.c \
- $(srcdir)/t_inq_cred.c $(srcdir)/t_inq_ctx.c \
+ $(srcdir)/t_accname.c $(srcdir)/t_add_cred.c $(srcdir)/t_bindings.c \
+ $(srcdir)/t_ccselect.c $(srcdir)/t_ciflags.c $(srcdir)/t_context.c \
+ $(srcdir)/t_credstore.c $(srcdir)/t_enctypes.c $(srcdir)/t_err.c \
+ $(srcdir)/t_export_cred.c $(srcdir)/t_export_name.c \
+ $(srcdir)/t_gssexts.c $(srcdir)/t_imp_cred.c $(srcdir)/t_imp_name.c \
+ $(srcdir)/t_invalid.c $(srcdir)/t_inq_cred.c $(srcdir)/t_inq_ctx.c \
$(srcdir)/t_inq_mechs_name.c $(srcdir)/t_iov.c \
$(srcdir)/t_lifetime.c $(srcdir)/t_namingexts.c $(srcdir)/t_oid.c \
$(srcdir)/t_pcontok.c $(srcdir)/t_prf.c $(srcdir)/t_s4u.c \
$(srcdir)/t_s4u2proxy_krb5.c $(srcdir)/t_saslname.c \
$(srcdir)/t_spnego.c $(srcdir)/t_srcattrs.c
-OBJS= ccinit.o ccrefresh.o common.o t_accname.o t_add_cred.o t_ccselect.o \
- t_ciflags.o t_context.o t_credstore.o t_enctypes.o t_err.o \
- t_export_cred.o t_export_name.o t_gssexts.o t_imp_cred.o t_imp_name.o \
- t_invalid.o t_inq_cred.o t_inq_ctx.o t_inq_mechs_name.o t_iov.o \
- t_lifetime.o t_namingexts.o t_oid.o t_pcontok.o t_prf.o t_s4u.o \
- t_s4u2proxy_krb5.o t_saslname.o t_spnego.o t_srcattrs.o
+OBJS= ccinit.o ccrefresh.o common.o t_accname.o t_add_cred.o t_bindings.o \
+ t_ccselect.o t_ciflags.o t_context.o t_credstore.o t_enctypes.o \
+ t_err.o t_export_cred.o t_export_name.o t_gssexts.o t_imp_cred.o \
+ t_imp_name.o t_invalid.o t_inq_cred.o t_inq_ctx.o t_inq_mechs_name.o \
+ t_iov.o t_lifetime.o t_namingexts.o t_oid.o t_pcontok.o t_prf.o \
+ t_s4u.o t_s4u2proxy_krb5.o t_saslname.o t_spnego.o t_srcattrs.o
COMMON_DEPS= common.o $(GSS_DEPLIBS) $(KRB5_BASE_DEPLIBS)
COMMON_LIBS= common.o $(GSS_LIBS) $(KRB5_BASE_LIBS)
-all: ccinit ccrefresh t_accname t_add_cred t_ccselect t_ciflags t_context \
- t_credstore t_enctypes t_err t_export_cred t_export_name t_gssexts \
- t_imp_cred t_imp_name t_invalid t_inq_cred t_inq_ctx t_inq_mechs_name \
- t_iov t_lifetime t_namingexts t_oid t_pcontok t_prf t_s4u \
- t_s4u2proxy_krb5 t_saslname t_spnego t_srcattrs
+all: ccinit ccrefresh t_accname t_add_cred t_bindings t_ccselect t_ciflags \
+ t_context t_credstore t_enctypes t_err t_export_cred t_export_name \
+ t_gssexts t_imp_cred t_imp_name t_invalid t_inq_cred t_inq_ctx \
+ t_inq_mechs_name t_iov t_lifetime t_namingexts t_oid t_pcontok t_prf \
+ t_s4u t_s4u2proxy_krb5 t_saslname t_spnego t_srcattrs
check-unix: t_oid
$(RUN_TEST) ./t_invalid
@@ -43,11 +43,12 @@ check-unix: t_oid
$(RUN_TEST) ./t_prf
$(RUN_TEST) ./t_imp_name
-check-pytests: ccinit ccrefresh t_accname t_add_cred t_ccselect t_ciflags \
- t_context t_credstore t_enctypes t_err t_export_cred t_export_name \
- t_imp_cred t_inq_cred t_inq_ctx t_inq_mechs_name t_iov t_lifetime \
- t_pcontok t_s4u t_s4u2proxy_krb5 t_spnego t_srcattrs
+check-pytests: ccinit ccrefresh t_accname t_add_cred t_bindings t_ccselect \
+ t_ciflags t_context t_credstore t_enctypes t_err t_export_cred \
+ t_export_name t_imp_cred t_inq_cred t_inq_ctx t_inq_mechs_name t_iov \
+ t_lifetime t_pcontok t_s4u t_s4u2proxy_krb5 t_spnego t_srcattrs
$(RUNPYTEST) $(srcdir)/t_gssapi.py $(PYTESTFLAGS)
+ $(RUNPYTEST) $(srcdir)/t_bindings.py $(PYTESTFLAGS)
$(RUNPYTEST) $(srcdir)/t_ccselect.py $(PYTESTFLAGS)
$(RUNPYTEST) $(srcdir)/t_client_keytab.py $(PYTESTFLAGS)
$(RUNPYTEST) $(srcdir)/t_enctypes.py $(PYTESTFLAGS)
@@ -64,6 +65,8 @@ t_accname: t_accname.o $(COMMON_DEPS)
$(CC_LINK) -o $@ t_accname.o $(COMMON_LIBS)
t_add_cred: t_add_cred.o $(COMMON_DEPS)
$(CC_LINK) -o $@ t_add_cred.o $(COMMON_LIBS)
+t_bindings: t_bindings.o $(COMMON_DEPS)
+ $(CC_LINK) -o $@ t_bindings.o $(COMMON_LIBS)
t_ccselect: t_ccselect.o $(COMMON_DEPS)
$(CC_LINK) -o $@ t_ccselect.o $(COMMON_LIBS)
t_ciflags: t_ciflags.o $(COMMON_DEPS)
@@ -118,8 +121,8 @@ t_srcattrs: t_srcattrs.o $(COMMON_DEPS)
$(CC_LINK) -o $@ t_srcattrs.o $(COMMON_LIBS)
clean:
- $(RM) ccinit ccrefresh t_accname t_add_cred t_ccselect t_ciflags
- $(RM) t_context t_credstore t_enctypes t_err t_export_cred
+ $(RM) ccinit ccrefresh t_accname t_add_cred t_bindings t_ccselect
+ $(RM) t_ciflags t_context t_credstore t_enctypes t_err t_export_cred
$(RM) t_export_name t_gssexts t_imp_cred t_imp_name t_invalid
$(RM) t_inq_cred t_inq_ctx t_inq_mechs_name t_iov t_lifetime
$(RM) t_namingexts t_oid t_pcontok t_prf t_s4u t_s4u2proxy_krb5
diff --git a/src/tests/gssapi/common.c b/src/tests/gssapi/common.c
index 83e9d9bb8..7ba72f7b2 100644
--- a/src/tests/gssapi/common.c
+++ b/src/tests/gssapi/common.c
@@ -115,6 +115,20 @@ establish_contexts(gss_OID imech, gss_cred_id_t icred, gss_cred_id_t acred,
gss_name_t tname, OM_uint32 flags, gss_ctx_id_t *ictx,
gss_ctx_id_t *actx, gss_name_t *src_name, gss_OID *amech,
gss_cred_id_t *deleg_cred)
+{
+ return establish_contexts_ex(imech, icred, acred, tname, flags, ictx, actx,
+ GSS_C_NO_CHANNEL_BINDINGS,
+ GSS_C_NO_CHANNEL_BINDINGS, NULL, src_name,
+ amech, deleg_cred);
+}
+
+void
+establish_contexts_ex(gss_OID imech, gss_cred_id_t icred, gss_cred_id_t acred,
+ gss_name_t tname, OM_uint32 flags, gss_ctx_id_t *ictx,
+ gss_ctx_id_t *actx, gss_channel_bindings_t icb,
+ gss_channel_bindings_t acb, OM_uint32 *aret_flags,
+ gss_name_t *src_name, gss_OID *amech,
+ gss_cred_id_t *deleg_cred)
{
OM_uint32 minor, imaj, amaj;
gss_buffer_desc itok, atok;
@@ -126,17 +140,16 @@ establish_contexts(gss_OID imech, gss_cred_id_t icred, gss_cred_id_t acred,
for (;;) {
(void)gss_release_buffer(&minor, &itok);
imaj = gss_init_sec_context(&minor, icred, ictx, tname, imech, flags,
- GSS_C_INDEFINITE,
- GSS_C_NO_CHANNEL_BINDINGS, &atok, NULL,
- &itok, NULL, NULL);
+ GSS_C_INDEFINITE, icb, &atok, NULL, &itok,
+ NULL, NULL);
check_gsserr("gss_init_sec_context", imaj, minor);
if (amaj == GSS_S_COMPLETE)
break;
(void)gss_release_buffer(&minor, &atok);
- amaj = gss_accept_sec_context(&minor, actx, acred, &itok,
- GSS_C_NO_CHANNEL_BINDINGS, src_name,
- amech, &atok, NULL, NULL, deleg_cred);
+ amaj = gss_accept_sec_context(&minor, actx, acred, &itok, acb,
+ src_name, amech, &atok, aret_flags, NULL,
+ deleg_cred);
check_gsserr("gss_accept_sec_context", amaj, minor);
(void)gss_release_buffer(&minor, &itok);
if (imaj == GSS_S_COMPLETE)
diff --git a/src/tests/gssapi/common.h b/src/tests/gssapi/common.h
index ae11b51d4..a5c8f87e6 100644
--- a/src/tests/gssapi/common.h
+++ b/src/tests/gssapi/common.h
@@ -62,6 +62,15 @@ void establish_contexts(gss_OID imech, gss_cred_id_t icred,
gss_name_t *src_name, gss_OID *amech,
gss_cred_id_t *deleg_cred);
+/* Establish contexts with channel bindings. */
+void establish_contexts_ex(gss_OID imech, gss_cred_id_t icred,
+ gss_cred_id_t acred, gss_name_t tname,
+ OM_uint32 flags, gss_ctx_id_t *ictx,
+ gss_ctx_id_t *actx, gss_channel_bindings_t icb,
+ gss_channel_bindings_t acb, OM_uint32 *aret_flags,
+ gss_name_t *src_name, gss_OID *amech,
+ gss_cred_id_t *deleg_cred);
+
/* Export *cred to a token, then release *cred and replace it by re-importing
* the token. */
void export_import_cred(gss_cred_id_t *cred);
diff --git a/src/tests/gssapi/deps b/src/tests/gssapi/deps
index acd0e96f8..73e4d9a74 100644
--- a/src/tests/gssapi/deps
+++ b/src/tests/gssapi/deps
@@ -33,6 +33,10 @@ $(OUTPRE)t_add_cred.$(OBJEXT): $(BUILDTOP)/include/gssapi/gssapi.h \
$(BUILDTOP)/include/gssapi/gssapi_ext.h $(BUILDTOP)/include/gssapi/gssapi_krb5.h \
$(BUILDTOP)/include/krb5/krb5.h $(COM_ERR_DEPS) $(top_srcdir)/include/krb5.h \
common.h t_add_cred.c
+$(OUTPRE)t_bindings.$(OBJEXT): $(BUILDTOP)/include/gssapi/gssapi.h \
+ $(BUILDTOP)/include/gssapi/gssapi_ext.h $(BUILDTOP)/include/gssapi/gssapi_krb5.h \
+ $(BUILDTOP)/include/krb5/krb5.h $(COM_ERR_DEPS) $(top_srcdir)/include/krb5.h \
+ common.h t_bindings.c
$(OUTPRE)t_ccselect.$(OBJEXT): $(BUILDTOP)/include/gssapi/gssapi.h \
$(BUILDTOP)/include/gssapi/gssapi_ext.h $(BUILDTOP)/include/gssapi/gssapi_krb5.h \
$(BUILDTOP)/include/krb5/krb5.h $(COM_ERR_DEPS) $(top_srcdir)/include/krb5.h \
diff --git a/src/tests/gssapi/t_bindings.c b/src/tests/gssapi/t_bindings.c
new file mode 100644
index 000000000..e8906715b
--- /dev/null
+++ b/src/tests/gssapi/t_bindings.c
@@ -0,0 +1,111 @@
+/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
+/*
+ * Copyright (C) 2020 by Red Hat, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * * 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 COPYRIGHT HOLDERS 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
+ * COPYRIGHT HOLDER 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.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+#include "common.h"
+
+/*
+ * Establish contexts (without and with GSS_C_DCE_STYLE) with the default
+ * initiator name, a specified principal name as target name, initiator
+ * bindings, and acceptor bindings. If any call is unsuccessful, display an
+ * error message. Output "yes" or "no" to indicate whether the contexts were
+ * reported as channel-bound on the acceptor. Exit with status 0 if all
+ * operations are successful, or 1 if not.
+ *
+ * Usage: ./t_bindings [-s] targetname icb acb
+ *
+ * An icb or abc value of "-" will not specify channel bindings.
+ */
+
+int
+main(int argc, char *argv[])
+{
+ OM_uint32 minor, flags1, flags2;
+ gss_name_t target_name;
+ gss_ctx_id_t ictx, actx;
+ struct gss_channel_bindings_struct icb_data = {0}, acb_data = {0};
+ gss_channel_bindings_t icb = GSS_C_NO_CHANNEL_BINDINGS;
+ gss_channel_bindings_t acb = GSS_C_NO_CHANNEL_BINDINGS;
+ gss_OID_desc *mech;
+
+ argv++;
+ argc--;
+ if (*argv != NULL && strcmp(*argv, "-s") == 0) {
+ mech = &mech_spnego;
+ argv++;
+ argc--;
+ } else {
+ mech = &mech_krb5;
+ }
+
+ if (argc != 3) {
+ fprintf(stderr, "Usage: t_bindings [-s] targetname icb acb\n");
+ return 1;
+ }
+
+ target_name = import_name(argv[0]);
+
+ if (strcmp(argv[1], "-") != 0) {
+ icb_data.application_data.length = strlen(argv[1]);
+ icb_data.application_data.value = argv[1];
+ icb = &icb_data;
+ }
+
+ if (strcmp(argv[2], "-") != 0) {
+ acb_data.application_data.length = strlen(argv[2]);
+ acb_data.application_data.value = argv[2];
+ acb = &acb_data;
+ }
+
+ establish_contexts_ex(mech, GSS_C_NO_CREDENTIAL, GSS_C_NO_CREDENTIAL,
+ target_name, 0, &ictx, &actx, icb, acb, &flags1,
+ NULL, NULL, NULL);
+
+ /* Try again with GSS_C_DCE_STYLE */
+ (void)gss_delete_sec_context(&minor, &ictx, NULL);
+ (void)gss_delete_sec_context(&minor, &actx, NULL);
+
+ establish_contexts_ex(mech, GSS_C_NO_CREDENTIAL, GSS_C_NO_CREDENTIAL,
+ target_name, GSS_C_DCE_STYLE, &ictx, &actx, icb, acb,
+ &flags2, NULL, NULL, NULL);
+ assert((flags1 & GSS_C_CHANNEL_BOUND_FLAG) ==
+ (flags2 & GSS_C_CHANNEL_BOUND_FLAG));
+ printf("%s\n", (flags1 & GSS_C_CHANNEL_BOUND_FLAG) ? "yes" : "no");
+
+ (void)gss_delete_sec_context(&minor, &ictx, NULL);
+ (void)gss_delete_sec_context(&minor, &actx, NULL);
+ (void)gss_release_name(&minor, &target_name);
+
+ return 0;
+}
diff --git a/src/tests/gssapi/t_bindings.py b/src/tests/gssapi/t_bindings.py
new file mode 100644
index 000000000..f377977b6
--- /dev/null
+++ b/src/tests/gssapi/t_bindings.py
@@ -0,0 +1,43 @@
+from k5test import *
+
+realm = K5Realm()
+server = 'p:' + realm.host_princ
+
+mark('krb5 channel bindings')
+realm.run(['./t_bindings', server, '-', '-'], expected_msg='no')
+realm.run(['./t_bindings', server, 'a', '-'], expected_msg='no')
+realm.run(['./t_bindings', server, 'a', 'a'], expected_msg='yes')
+realm.run(['./t_bindings', server, '-', 'a'], expected_msg='no')
+realm.run(['./t_bindings', server, 'a', 'x'],
+ expected_code=1, expected_msg='Incorrect channel bindings')
+
+mark('SPNEGO channel bindings')
+realm.run(['./t_bindings', '-s', server, '-', '-'], expected_msg='no')
+realm.run(['./t_bindings', '-s', server, 'a', '-'], expected_msg='no')
+realm.run(['./t_bindings', '-s', server, 'a', 'a'], expected_msg='yes')
+realm.run(['./t_bindings', '-s', server, '-', 'a'], expected_msg='no')
+realm.run(['./t_bindings', '-s', server, 'a', 'x'],
+ expected_code=1, expected_msg='Incorrect channel bindings')
+
+client_aware_conf = {'libdefaults': {'client_aware_channel_bindings': 'true'}}
+e = realm.special_env('cb_aware', False, krb5_conf=client_aware_conf)
+
+mark('krb5 client_aware_channel_bindings')
+realm.run(['./t_bindings', server, '-', '-'], env=e, expected_msg='no')
+realm.run(['./t_bindings', server, 'a', '-'], env=e, expected_msg='no')
+realm.run(['./t_bindings', server, 'a', 'a'], env=e, expected_msg='yes')
+realm.run(['./t_bindings', server, '-', 'a'], env=e,
+ expected_code=1, expected_msg='Incorrect channel bindings')
+realm.run(['./t_bindings', server, 'a', 'x'], env=e,
+ expected_code=1, expected_msg='Incorrect channel bindings')
+
+mark('SPNEGO client_aware_channel_bindings')
+realm.run(['./t_bindings', '-s', server, '-', '-'], env=e, expected_msg='no')
+realm.run(['./t_bindings', '-s', server, 'a', '-'], env=e, expected_msg='no')
+realm.run(['./t_bindings', '-s', server, 'a', 'a'], env=e, expected_msg='yes')
+realm.run(['./t_bindings', '-s', server, '-', 'a'], env=e,
+ expected_code=1, expected_msg='Incorrect channel bindings')
+realm.run(['./t_bindings', '-s', server, 'a', 'x'], env=e,
+ expected_code=1, expected_msg='Incorrect channel bindings')
+
+success('channel bindings tests')
diff --git a/src/tests/gssapi/t_negoex.py b/src/tests/gssapi/t_negoex.py
index 88470d2fa..a218899c4 100644
--- a/src/tests/gssapi/t_negoex.py
+++ b/src/tests/gssapi/t_negoex.py
@@ -139,4 +139,11 @@ msgs = ('sending [3]AP_REQUEST', 'sending [7]CHALLENGE', 'sending [8]VERIFY',
'sending [11]CHALLENGE', 'sending [12]VERIFY', 'sending [13]VERIFY')
test({'HOPS': '4', 'KEY': 'accept-always'}, expected_trace=())
+mark('channel bindings')
+e = realm.env.copy()
+e.update({'HOPS': '1', 'GSS_INIT_BINDING': 'a', 'GSS_ACCEPT_BINDING': 'b'})
+# The test mech will verify that the bindings are communicated to the
+# mech, but does not set the channel-bound flag.
+realm.run(['./t_bindings', '-s', 'h:host', 'a', 'b'], env=e, expected_msg='no')
+
success('NegoEx tests')

264
Add-client_aware_channel_bindings-option.patch Normal file
View File

@ -0,0 +1,264 @@
From 2a08fe3d2d1972df4ffe37d4bb64b161889ff988 Mon Sep 17 00:00:00 2001
From: Isaac Boukris <iboukris@gmail.com>
Date: Tue, 10 Mar 2020 13:13:17 +0100
Subject: [PATCH] Add client_aware_channel_bindings option
Add client support for KERB_AP_OPTIONS_CBT in the form of a profile
option "client_aware_gss_bindings". Adjust the make_etype_list()
helper so that enctype negotiation and AP_OPTIONS can be included in
the same IF-RELEVANT wrapper.
[ghudson@mit.edu: refactored; edited documentation; wrote commit
message]
ticket: 8900
(cherry picked from commit 225e6ef7f021cd1a8ef2a054af0ca58b7288fd81)
---
doc/admin/conf_files/krb5_conf.rst | 6 +
src/include/k5-int.h | 1 +
src/lib/krb5/krb/mk_req_ext.c | 177 +++++++++++++++--------------
3 files changed, 98 insertions(+), 86 deletions(-)
diff --git a/doc/admin/conf_files/krb5_conf.rst b/doc/admin/conf_files/krb5_conf.rst
index a7e7a29d1..7f2879640 100644
--- a/doc/admin/conf_files/krb5_conf.rst
+++ b/doc/admin/conf_files/krb5_conf.rst
@@ -382,6 +382,12 @@ The libdefaults section may contain any of the following relations:
credentials will fail if the client machine does not have a
keytab. The default value is false.
+**client_aware_channel_bindings**
+ If this flag is true, then all application protocol authentication
+ requests will be flagged to indicate that the application supports
+ channel bindings when operating over a secure channel. The
+ default value is false.
+
.. _realms:
[realms]
diff --git a/src/include/k5-int.h b/src/include/k5-int.h
index 0d9af3d95..eb18a4cd6 100644
--- a/src/include/k5-int.h
+++ b/src/include/k5-int.h
@@ -299,6 +299,7 @@ typedef unsigned char u_char;
#define KRB5_CONF_V4_INSTANCE_CONVERT "v4_instance_convert"
#define KRB5_CONF_V4_REALM "v4_realm"
#define KRB5_CONF_VERIFY_AP_REQ_NOFAIL "verify_ap_req_nofail"
+#define KRB5_CONF_CLIENT_AWARE_GSS_BINDINGS "client_aware_channel_bindings"
/* Cache configuration variables */
#define KRB5_CC_CONF_FAST_AVAIL "fast_avail"
diff --git a/src/lib/krb5/krb/mk_req_ext.c b/src/lib/krb5/krb/mk_req_ext.c
index 9fc6a0e52..08504860c 100644
--- a/src/lib/krb5/krb/mk_req_ext.c
+++ b/src/lib/krb5/krb/mk_req_ext.c
@@ -68,10 +68,9 @@
*/
static krb5_error_code
-make_etype_list(krb5_context context,
- krb5_enctype *desired_etypes,
- krb5_enctype tkt_enctype,
- krb5_authdata ***authdata);
+make_ap_authdata(krb5_context context, krb5_enctype *desired_enctypes,
+ krb5_enctype tkt_enctype, krb5_boolean client_aware_cb,
+ krb5_authdata ***authdata_out);
static krb5_error_code
generate_authenticator(krb5_context,
@@ -263,7 +262,8 @@ generate_authenticator(krb5_context context, krb5_authenticator *authent,
krb5_enctype tkt_enctype)
{
krb5_error_code retval;
- krb5_authdata **ext_authdata = NULL;
+ krb5_authdata **ext_authdata = NULL, **ap_authdata, **combined;
+ int client_aware_cb;
authent->client = client;
authent->checksum = cksum;
@@ -297,99 +297,104 @@ generate_authenticator(krb5_context context, krb5_authenticator *authent,
krb5_free_authdata(context, ext_authdata);
}
- /* Only send EtypeList if we prefer another enctype to tkt_enctype */
- if (desired_etypes != NULL && desired_etypes[0] != tkt_enctype) {
- TRACE_MK_REQ_ETYPES(context, desired_etypes);
- retval = make_etype_list(context, desired_etypes, tkt_enctype,
- &authent->authorization_data);
+ retval = profile_get_boolean(context->profile, KRB5_CONF_LIBDEFAULTS,
+ KRB5_CONF_CLIENT_AWARE_GSS_BINDINGS, NULL,
+ FALSE, &client_aware_cb);
+ if (retval)
+ return retval;
+
+ /* Add etype negotiation or channel-binding awareness authdata to the
+ * front, if appropriate. */
+ retval = make_ap_authdata(context, desired_etypes, tkt_enctype,
+ client_aware_cb, &ap_authdata);
+ if (retval)
+ return retval;
+ if (ap_authdata != NULL) {
+ retval = krb5_merge_authdata(context, ap_authdata,
+ authent->authorization_data, &combined);
+ krb5_free_authdata(context, ap_authdata);
if (retval)
return retval;
+ krb5_free_authdata(context, authent->authorization_data);
+ authent->authorization_data = combined;
}
return(krb5_us_timeofday(context, &authent->ctime, &authent->cusec));
}
-/* RFC 4537 */
+/* Set *out to a DER-encoded RFC 4537 etype list, or to NULL if no etype list
+ * should be sent. */
static krb5_error_code
-make_etype_list(krb5_context context,
- krb5_enctype *desired_etypes,
- krb5_enctype tkt_enctype,
- krb5_authdata ***authdata)
+make_etype_list(krb5_context context, krb5_enctype *desired_enctypes,
+ krb5_enctype tkt_enctype, krb5_data **out)
{
- krb5_error_code code;
- krb5_etype_list etypes;
- krb5_data *enc_etype_list;
- krb5_data *ad_if_relevant;
- krb5_authdata *etype_adata[2], etype_adatum, **adata;
- int i;
+ krb5_etype_list etlist;
+ int count;
- etypes.etypes = desired_etypes;
+ *out = NULL;
- for (etypes.length = 0;
- etypes.etypes[etypes.length] != ENCTYPE_NULL;
- etypes.length++)
- {
- /*
- * RFC 4537:
- *
- * If the enctype of the ticket session key is included in the enctype
- * list sent by the client, it SHOULD be the last on the list;
- */
- if (etypes.length && etypes.etypes[etypes.length - 1] == tkt_enctype)
+ /* Only send a list if we prefer another enctype to tkt_enctype. */
+ if (desired_enctypes == NULL || desired_enctypes[0] == tkt_enctype)
+ return 0;
+
+ /* Count elements of desired_etypes, stopping at tkt_enctypes if present.
+ * (Per RFC 4537, it must be the last option if it is included.) */
+ for (count = 0; desired_enctypes[count] != ENCTYPE_NULL; count++) {
+ if (count > 0 && desired_enctypes[count - 1] == tkt_enctype)
break;
}
- code = encode_krb5_etype_list(&etypes, &enc_etype_list);
- if (code) {
- return code;
- }
-
- etype_adatum.magic = KV5M_AUTHDATA;
- etype_adatum.ad_type = KRB5_AUTHDATA_ETYPE_NEGOTIATION;
- etype_adatum.length = enc_etype_list->length;
- etype_adatum.contents = (krb5_octet *)enc_etype_list->data;
-
- etype_adata[0] = &etype_adatum;
- etype_adata[1] = NULL;
-
- /* Wrap in AD-IF-RELEVANT container */
- code = encode_krb5_authdata(etype_adata, &ad_if_relevant);
- if (code) {
- krb5_free_data(context, enc_etype_list);
- return code;
- }
-
- krb5_free_data(context, enc_etype_list);
-
- adata = *authdata;
- if (adata == NULL) {
- adata = (krb5_authdata **)calloc(2, sizeof(krb5_authdata *));
- i = 0;
- } else {
- for (i = 0; adata[i] != NULL; i++)
- ;
-
- adata = (krb5_authdata **)realloc(*authdata,
- (i + 2) * sizeof(krb5_authdata *));
- }
- if (adata == NULL) {
- krb5_free_data(context, ad_if_relevant);
- return ENOMEM;
- }
- *authdata = adata;
-
- adata[i] = (krb5_authdata *)malloc(sizeof(krb5_authdata));
- if (adata[i] == NULL) {
- krb5_free_data(context, ad_if_relevant);
- return ENOMEM;
- }
- adata[i]->magic = KV5M_AUTHDATA;
- adata[i]->ad_type = KRB5_AUTHDATA_IF_RELEVANT;
- adata[i]->length = ad_if_relevant->length;
- adata[i]->contents = (krb5_octet *)ad_if_relevant->data;
- free(ad_if_relevant); /* contents owned by adata[i] */
-
- adata[i + 1] = NULL;
-
- return 0;
+ etlist.etypes = desired_enctypes;
+ etlist.length = count;
+ return encode_krb5_etype_list(&etlist, out);
+}
+
+/* Set *authdata_out to appropriate authenticator authdata for the request,
+ * encoded in a single AD_IF_RELEVANT element. */
+static krb5_error_code
+make_ap_authdata(krb5_context context, krb5_enctype *desired_enctypes,
+ krb5_enctype tkt_enctype, krb5_boolean client_aware_cb,
+ krb5_authdata ***authdata_out)
+{
+ krb5_error_code ret;
+ krb5_authdata etypes_ad, flags_ad, *list[3];
+ krb5_data *der_etypes = NULL;
+ size_t count = 0;
+ uint8_t flagbuf[4];
+ const uint32_t KERB_AP_OPTIONS_CBT = 0x4000;
+
+ *authdata_out = NULL;
+
+ /* Include an ETYPE_NEGOTIATION element if appropriate. */
+ ret = make_etype_list(context, desired_enctypes, tkt_enctype, &der_etypes);
+ if (ret)
+ goto cleanup;
+ if (der_etypes != NULL) {
+ etypes_ad.magic = KV5M_AUTHDATA;
+ etypes_ad.ad_type = KRB5_AUTHDATA_ETYPE_NEGOTIATION;
+ etypes_ad.length = der_etypes->length;
+ etypes_ad.contents = (uint8_t *)der_etypes->data;
+ list[count++] = &etypes_ad;
+ }
+
+ /* Include an AP_OPTIONS element if the CBT flag is configured. */
+ if (client_aware_cb != 0) {
+ store_32_le(KERB_AP_OPTIONS_CBT, flagbuf);
+ flags_ad.magic = KV5M_AUTHDATA;
+ flags_ad.ad_type = KRB5_AUTHDATA_AP_OPTIONS;
+ flags_ad.length = 4;
+ flags_ad.contents = flagbuf;
+ list[count++] = &flags_ad;
+ }
+
+ if (count > 0) {
+ list[count] = NULL;
+ ret = krb5_encode_authdata_container(context,
+ KRB5_AUTHDATA_IF_RELEVANT,
+ list, authdata_out);
+ }
+
+cleanup:
+ krb5_free_data(context, der_etypes);
+ return ret;
}

2
Default-dns_canonicalize_hostname-to-fallback.patch
View File

@ -1,4 +1,4 @@
From d003b4aa8dce14967725d6607c54ceb884b3647c Mon Sep 17 00:00:00 2001
From 07179e38e5ee72e82ebc77a1c8d73e34905268b7 Mon Sep 17 00:00:00 2001
From: Greg Hudson <ghudson@mit.edu>
Date: Wed, 27 May 2020 18:48:35 -0400
Subject: [PATCH] Default dns_canonicalize_hostname to "fallback"

91
Implement-GSS_C_CHANNEL_BOUND_FLAG.patch Normal file
View File

@ -0,0 +1,91 @@
From 3ea1d6296ced3a998e79356f9be212e4c5e6a5d5 Mon Sep 17 00:00:00 2001
From: Alexander Scheel <ascheel@redhat.com>
Date: Wed, 5 Jul 2017 11:38:30 -0400
Subject: [PATCH] Implement GSS_C_CHANNEL_BOUND_FLAG
Define a new channel-bound GSS return flag, and set it in the krb5
mech if the initiator sent channel bindings matching the acceptor's.
Do not error out if the acceptor specifies channel bindings and the
initiator does not send them.
[ghudson@mit.edu: simplified code changes; fleshed out commit message]
[iboukris: cherry-picked from another PR and reduced in scope]
ticket: 8899 (new)
(cherry picked from commit 429a31146083fac21958631c2af572b08ec91022)
---
src/lib/gssapi/generic/gssapi_ext.h | 2 ++
src/lib/gssapi/krb5/accept_sec_context.c | 18 +++++++++++++-----
2 files changed, 15 insertions(+), 5 deletions(-)
diff --git a/src/lib/gssapi/generic/gssapi_ext.h b/src/lib/gssapi/generic/gssapi_ext.h
index 218456e44..c675e8ebb 100644
--- a/src/lib/gssapi/generic/gssapi_ext.h
+++ b/src/lib/gssapi/generic/gssapi_ext.h
@@ -595,6 +595,8 @@ gss_store_cred_into(
* attribute (along with any applicable RFC 5587 attributes).
*/
+#define GSS_C_CHANNEL_BOUND_FLAG 2048 /* 0x00000800 */
+
OM_uint32 KRB5_CALLCONV
gssspi_query_meta_data(
OM_uint32 *minor_status,
diff --git a/src/lib/gssapi/krb5/accept_sec_context.c b/src/lib/gssapi/krb5/accept_sec_context.c
index 70dd7fc0c..9d3e2f4fe 100644
--- a/src/lib/gssapi/krb5/accept_sec_context.c
+++ b/src/lib/gssapi/krb5/accept_sec_context.c
@@ -427,6 +427,9 @@ kg_process_extension(krb5_context context,
GSS_C_SEQUENCE_FLAG | GSS_C_DCE_STYLE | \
GSS_C_IDENTIFY_FLAG | GSS_C_EXTENDED_ERROR_FLAG)
+/* A zero-value channel binding, for comparison */
+static const uint8_t null_cb[CB_MD5_LEN];
+
/*
* The krb5 GSS mech appropriates the authenticator checksum field from RFC
* 4120 to store structured data instead of a checksum, indicated with checksum
@@ -435,9 +438,10 @@ kg_process_extension(krb5_context context,
*
* Interpret the checksum. Read delegated creds into *deleg_out if it is not
* NULL. Set *flags_out to the allowed subset of token flags, plus
- * GSS_C_DELEG_FLAG if a delegated credential was present. Process any
- * extensions found using exts. On error, set *code_out to a krb5_error code
- * for use as a minor status value.
+ * GSS_C_DELEG_FLAG if a delegated credential was present and
+ * GSS_C_CHANNEL_BOUND_FLAG if matching channel bindings are present. Process
+ * any extensions found using exts. On error, set *code_out to a krb5_error
+ * code for use as a minor status value.
*/
static OM_uint32
process_checksum(OM_uint32 *minor_status, krb5_context context,
@@ -450,7 +454,7 @@ process_checksum(OM_uint32 *minor_status, krb5_context context,
krb5_error_code code = 0;
OM_uint32 status, option_id, token_flags;
size_t cb_len, option_len;
- krb5_boolean valid;
+ krb5_boolean valid, token_cb_present = FALSE, cb_match = FALSE;
krb5_key subkey;
krb5_data option, empty = empty_data();
krb5_checksum cb_cksum;
@@ -516,7 +520,9 @@ process_checksum(OM_uint32 *minor_status, krb5_context context,
goto fail;
}
assert(cb_cksum.length == cb_len);
- if (k5_bcmp(token_cb, cb_cksum.contents, cb_len) != 0) {
+ token_cb_present = (k5_bcmp(token_cb, null_cb, cb_len) != 0);
+ cb_match = (k5_bcmp(token_cb, cb_cksum.contents, cb_len) == 0);
+ if (token_cb_present && !cb_match) {
status = GSS_S_BAD_BINDINGS;
goto fail;
}
@@ -525,6 +531,8 @@ process_checksum(OM_uint32 *minor_status, krb5_context context,
/* Read the token flags and accept some of them as context flags. */
token_flags = k5_input_get_uint32_le(&in);
*flags_out = token_flags & INITIATOR_FLAGS;
+ if (cb_match)
+ *flags_out |= GSS_C_CHANNEL_BOUND_FLAG;
/* Read the delegated credential if present. */
if (in.len >= 4 && (token_flags & GSS_C_DELEG_FLAG)) {

102
Implement-KERB_AP_OPTIONS_CBT-server-side.patch Normal file
View File

@ -0,0 +1,102 @@
From 6407bf087fe53088d91efd09df736e979cd4e8db Mon Sep 17 00:00:00 2001
From: Isaac Boukris <iboukris@gmail.com>
Date: Mon, 9 Mar 2020 16:04:21 +0100
Subject: [PATCH] Implement KERB_AP_OPTIONS_CBT (server side)
Add server support for Microsoft's KERB_AP_OPTIONS_CBT as described in
MS-KILE. If the client includes the AP option in the authenticator
authdata and the server passed channel bindings, require the bindings
to match.
[ghudson@mit.edu: refactored to put more logic in the helper function;
added a comment; clarified commit message]
ticket: 8900 (new)
(cherry picked from commit 4f7c77b64a048ca5e3199b26b31493698c777a9c)
---
src/include/krb5/krb5.hin | 1 +
src/lib/gssapi/krb5/accept_sec_context.c | 45 +++++++++++++++++++++++-
2 files changed, 45 insertions(+), 1 deletion(-)
diff --git a/src/include/krb5/krb5.hin b/src/include/krb5/krb5.hin
index f8269fb17..9264bede1 100644
--- a/src/include/krb5/krb5.hin
+++ b/src/include/krb5/krb5.hin
@@ -1915,6 +1915,7 @@ krb5_verify_checksum(krb5_context context, krb5_cksumtype ctype,
#define KRB5_AUTHDATA_SIGNTICKET 512 /**< formerly 142 in krb5 1.8 */
#define KRB5_AUTHDATA_FX_ARMOR 71
#define KRB5_AUTHDATA_AUTH_INDICATOR 97
+#define KRB5_AUTHDATA_AP_OPTIONS 143
/** @} */ /* end of KRB5_AUTHDATA group */
/* password change constants */
diff --git a/src/lib/gssapi/krb5/accept_sec_context.c b/src/lib/gssapi/krb5/accept_sec_context.c
index 9d3e2f4fe..175a24c4e 100644
--- a/src/lib/gssapi/krb5/accept_sec_context.c
+++ b/src/lib/gssapi/krb5/accept_sec_context.c
@@ -430,6 +430,32 @@ kg_process_extension(krb5_context context,
/* A zero-value channel binding, for comparison */
static const uint8_t null_cb[CB_MD5_LEN];
+/* Look for AP_OPTIONS in authdata. If present and the options include
+ * KERB_AP_OPTIONS_CBT, set *cbt_out to true. */
+static krb5_error_code
+check_cbt(krb5_context context, krb5_authdata **authdata,
+ krb5_boolean *cbt_out)
+{
+ krb5_error_code code;
+ uint32_t ad_ap_options;
+ const uint32_t KERB_AP_OPTIONS_CBT = 0x4000;
+
+ *cbt_out = FALSE;
+
+ code = krb5_find_authdata(context, NULL, authdata,
+ KRB5_AUTHDATA_AP_OPTIONS, &authdata);
+ if (code || authdata == NULL)
+ return code;
+ if (authdata[1] != NULL || authdata[0]->length != 4)
+ return KRB5KRB_AP_ERR_MSG_TYPE;
+
+ ad_ap_options = load_32_le(authdata[0]->contents);
+ if (ad_ap_options & KERB_AP_OPTIONS_CBT)
+ *cbt_out = TRUE;
+
+ return 0;
+}
+
/*
* The krb5 GSS mech appropriates the authenticator checksum field from RFC
* 4120 to store structured data instead of a checksum, indicated with checksum
@@ -454,7 +480,7 @@ process_checksum(OM_uint32 *minor_status, krb5_context context,
krb5_error_code code = 0;
OM_uint32 status, option_id, token_flags;
size_t cb_len, option_len;
- krb5_boolean valid, token_cb_present = FALSE, cb_match = FALSE;
+ krb5_boolean valid, client_cbt, token_cb_present = FALSE, cb_match = FALSE;
krb5_key subkey;
krb5_data option, empty = empty_data();
krb5_checksum cb_cksum;
@@ -582,6 +608,23 @@ process_checksum(OM_uint32 *minor_status, krb5_context context,
}
}
+ /*
+ * If the client asserts the KERB_AP_OPTIONS_CBT flag (from MS-KILE) in the
+ * authenticator authdata, and the acceptor passed channel bindings,
+ * require matching channel bindings from the client. The intent is to
+ * prevent an authenticator generated for use outside of a TLS channel from
+ * being used inside of one.
+ */
+ code = check_cbt(context, authenticator->authorization_data, &client_cbt);
+ if (code) {
+ status = GSS_S_FAILURE;
+ goto fail;
+ }
+ if (client_cbt && acceptor_cb != GSS_C_NO_CHANNEL_BINDINGS && !cb_match) {
+ status = GSS_S_BAD_BINDINGS;
+ goto fail;
+ }
+
status = GSS_S_COMPLETE;
fail:

30
Improve-negoex_parse_token-code-hygiene.patch Normal file
View File

@ -0,0 +1,30 @@
From c726a72c68244129eb08b840b92144acfa776573 Mon Sep 17 00:00:00 2001
From: Robbie Harwood <rharwood@redhat.com>
Date: Tue, 9 Jun 2020 16:23:37 -0400
Subject: [PATCH] Improve negoex_parse_token() code hygiene
If the while loop in negoex_parse_token() runs for zero iterations,
major will be used initialized. Currently this cannot happen, but
only because both of the call sites check for zero-length tokens.
Initialize major for safety.
[ghudson@mit.edu: rewrote commit message]
(cherry picked from commit 4f91b6f8fa6fe1de662b3fdac0d59b7758ec642a)
---
src/lib/gssapi/spnego/negoex_util.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/lib/gssapi/spnego/negoex_util.c b/src/lib/gssapi/spnego/negoex_util.c
index 700368456..99580fd79 100644
--- a/src/lib/gssapi/spnego/negoex_util.c
+++ b/src/lib/gssapi/spnego/negoex_util.c
@@ -454,7 +454,7 @@ negoex_parse_token(OM_uint32 *minor, spnego_gss_ctx_id_t ctx,
gss_const_buffer_t token,
struct negoex_message **messages_out, size_t *count_out)
{
- OM_uint32 major;
+ OM_uint32 major = GSS_S_COMPLETE;
size_t count = 0;
struct k5input in;
struct negoex_message *messages = NULL, *newptr;

2
Omit-PA_FOR_USER-if-we-can-t-compute-its-checksum.patch
View File

@ -1,4 +1,4 @@
From 086de78292b8ae89aba8a72926831124da44205d Mon Sep 17 00:00:00 2001
From c36e826c70cb5b3bff8bd4371d47884cea30b3f4 Mon Sep 17 00:00:00 2001
From: Isaac Boukris <iboukris@gmail.com>
Date: Sat, 6 Jun 2020 11:03:37 +0200
Subject: [PATCH] Omit PA_FOR_USER if we can't compute its checksum

2
Pass-channel-bindings-through-SPNEGO.patch
View File

@ -1,4 +1,4 @@
From dd82ae2d390c4de1b8a7737a918d80d6829366dd Mon Sep 17 00:00:00 2001
From ee79bd43005245d3e5a2d3ec6d61146945e77717 Mon Sep 17 00:00:00 2001
From: Isaac Boukris <iboukris@gmail.com>
Date: Tue, 28 Apr 2020 18:15:55 +0200
Subject: [PATCH] Pass channel bindings through SPNEGO

479
Refactor-krb5-GSS-checksum-handling.patch Normal file
View File

@ -0,0 +1,479 @@
From a34b7c50e62c19f80d39ece6a72017dac781df64 Mon Sep 17 00:00:00 2001
From: Alexander Scheel <ascheel@redhat.com>
Date: Fri, 30 Jun 2017 16:03:01 -0400
Subject: [PATCH] Refactor krb5 GSS checksum handling
Separate out checksum handling from kg_accept_krb5() into a new helper
process_checksum().
[ghudson@mit.edu: simplified checksum processing and made it use
k5-input.h instead of TREAD_ macros; moved more flag handling into
helper]
[iboukris: adjusted helper function arguments, allowing access to the
full authenticator for subsequent changes]
(cherry picked from commit 64d56233f9816a2a93f6e8d3030c8ed6ce397735)
[rharwood@redhat.com: problem with typo fix commit, I think]
---
src/lib/gssapi/krb5/accept_sec_context.c | 383 +++++++++++------------
1 file changed, 179 insertions(+), 204 deletions(-)
diff --git a/src/lib/gssapi/krb5/accept_sec_context.c b/src/lib/gssapi/krb5/accept_sec_context.c
index c5bddb1e8..70dd7fc0c 100644
--- a/src/lib/gssapi/krb5/accept_sec_context.c
+++ b/src/lib/gssapi/krb5/accept_sec_context.c
@@ -98,6 +98,7 @@
*/
#include "k5-int.h"
+#include "k5-input.h"
#include "gssapiP_krb5.h"
#ifdef HAVE_MEMORY_H
#include <memory.h>
@@ -413,6 +414,174 @@ kg_process_extension(krb5_context context,
return code;
}
+/* The length of the MD5 channel bindings in an 0x8003 checksum */
+#define CB_MD5_LEN 16
+
+/* The minimum length of an 0x8003 checksum value (4-byte channel bindings
+ * length, 16-byte channel bindings, 4-byte flags) */
+#define MIN_8003_LEN (4 + CB_MD5_LEN + 4)
+
+/* The flags we accept from the initiator's authenticator checksum. */
+#define INITIATOR_FLAGS (GSS_C_INTEG_FLAG | GSS_C_CONF_FLAG | \
+ GSS_C_MUTUAL_FLAG | GSS_C_REPLAY_FLAG | \
+ GSS_C_SEQUENCE_FLAG | GSS_C_DCE_STYLE | \
+ GSS_C_IDENTIFY_FLAG | GSS_C_EXTENDED_ERROR_FLAG)
+
+/*
+ * The krb5 GSS mech appropriates the authenticator checksum field from RFC
+ * 4120 to store structured data instead of a checksum, indicated with checksum
+ * type 0x8003 (see RFC 4121 section 4.1.1). Some implementations instead send
+ * no checksum, or a regular checksum over empty data.
+ *
+ * Interpret the checksum. Read delegated creds into *deleg_out if it is not
+ * NULL. Set *flags_out to the allowed subset of token flags, plus
+ * GSS_C_DELEG_FLAG if a delegated credential was present. Process any
+ * extensions found using exts. On error, set *code_out to a krb5_error code
+ * for use as a minor status value.
+ */
+static OM_uint32
+process_checksum(OM_uint32 *minor_status, krb5_context context,
+ gss_channel_bindings_t acceptor_cb,
+ krb5_auth_context auth_context, krb5_flags ap_req_options,
+ krb5_authenticator *authenticator, krb5_gss_ctx_ext_t exts,
+ krb5_gss_cred_id_t *deleg_out, krb5_ui_4 *flags_out,
+ krb5_error_code *code_out)
+{
+ krb5_error_code code = 0;
+ OM_uint32 status, option_id, token_flags;
+ size_t cb_len, option_len;
+ krb5_boolean valid;
+ krb5_key subkey;
+ krb5_data option, empty = empty_data();
+ krb5_checksum cb_cksum;
+ const uint8_t *token_cb, *option_bytes;
+ struct k5input in;
+ const krb5_checksum *cksum = authenticator->checksum;
+
+ cb_cksum.contents = NULL;
+
+ if (cksum == NULL) {
+ /*
+ * Some SMB client implementations use handcrafted GSSAPI code that
+ * does not provide a checksum. MS-KILE documents that the Microsoft
+ * implementation considers a missing checksum acceptable; the server
+ * assumes all flags are unset in this case, and does not check channel
+ * bindings.
+ */
+ *flags_out = 0;
+ } else if (cksum->checksum_type != CKSUMTYPE_KG_CB) {
+ /* Samba sends a regular checksum. */
+ code = krb5_auth_con_getkey_k(context, auth_context, &subkey);
+ if (code) {
+ status = GSS_S_FAILURE;
+ goto fail;
+ }
+
+ /* Verifying the checksum ensures that this authenticator wasn't
+ * replayed from one with a checksum over actual data. */
+ code = krb5_k_verify_checksum(context, subkey,
+ KRB5_KEYUSAGE_AP_REQ_AUTH_CKSUM, &empty,
+ cksum, &valid);
+ krb5_k_free_key(context, subkey);
+ if (code || !valid) {
+ status = GSS_S_BAD_SIG;
+ goto fail;
+ }
+
+ /* Use ap_options from the request to guess the mutual flag. */
+ *flags_out = GSS_C_REPLAY_FLAG | GSS_C_SEQUENCE_FLAG;
+ if (ap_req_options & AP_OPTS_MUTUAL_REQUIRED)
+ *flags_out |= GSS_C_MUTUAL_FLAG;
+ } else {
+ /* The checksum must contain at least a fixed 24-byte part. */
+ if (cksum->length < MIN_8003_LEN) {
+ status = GSS_S_BAD_BINDINGS;
+ goto fail;
+ }
+
+ k5_input_init(&in, cksum->contents, cksum->length);
+ cb_len = k5_input_get_uint32_le(&in);
+ if (cb_len != CB_MD5_LEN) {
+ code = KG_BAD_LENGTH;
+ status = GSS_S_FAILURE;
+ goto fail;
+ }
+
+ token_cb = k5_input_get_bytes(&in, cb_len);
+ if (acceptor_cb != GSS_C_NO_CHANNEL_BINDINGS) {
+ code = kg_checksum_channel_bindings(context, acceptor_cb,
+ &cb_cksum);
+ if (code) {
+ status = GSS_S_BAD_BINDINGS;
+ goto fail;
+ }
+ assert(cb_cksum.length == cb_len);
+ if (k5_bcmp(token_cb, cb_cksum.contents, cb_len) != 0) {
+ status = GSS_S_BAD_BINDINGS;
+ goto fail;
+ }
+ }
+
+ /* Read the token flags and accept some of them as context flags. */
+ token_flags = k5_input_get_uint32_le(&in);
+ *flags_out = token_flags & INITIATOR_FLAGS;
+
+ /* Read the delegated credential if present. */
+ if (in.len >= 4 && (token_flags & GSS_C_DELEG_FLAG)) {
+ option_id = k5_input_get_uint16_le(&in);
+ option_len = k5_input_get_uint16_le(&in);
+ option_bytes = k5_input_get_bytes(&in, option_len);
+ option = make_data((uint8_t *)option_bytes, option_len);
+ if (in.status) {
+ code = KG_BAD_LENGTH;
+ status = GSS_S_FAILURE;
+ goto fail;
+ }
+ if (option_id != KRB5_GSS_FOR_CREDS_OPTION) {
+ status = GSS_S_FAILURE;
+ goto fail;
+ }
+
+ /* Store the delegated credential. */
+ code = rd_and_store_for_creds(context, auth_context, &option,
+ deleg_out);
+ if (code) {
+ status = GSS_S_FAILURE;
+ goto fail;
+ }
+ *flags_out |= GSS_C_DELEG_FLAG;
+ }
+
+ /* Process any extensions at the end of the checksum. Extensions use
+ * 4-byte big-endian tag and length instead of 2-byte little-endian. */
+ while (in.len > 0) {
+ option_id = k5_input_get_uint32_be(&in);
+ option_len = k5_input_get_uint32_be(&in);
+ option_bytes = k5_input_get_bytes(&in, option_len);
+ option = make_data((uint8_t *)option_bytes, option_len);
+ if (in.status) {
+ code = KG_BAD_LENGTH;
+ status = GSS_S_FAILURE;
+ goto fail;
+ }
+
+ code = kg_process_extension(context, auth_context, option_id,
+ &option, exts);
+ if (code) {
+ status = GSS_S_FAILURE;
+ goto fail;
+ }
+ }
+ }
+
+ status = GSS_S_COMPLETE;
+
+fail:
+ free(cb_cksum.contents);
+ *code_out = code;
+ return status;
+}
+
static OM_uint32
kg_accept_krb5(minor_status, context_handle,
verifier_cred_handle, input_token,
@@ -433,17 +602,13 @@ kg_accept_krb5(minor_status, context_handle,
krb5_gss_ctx_ext_t exts;
{
krb5_context context;
- unsigned char *ptr, *ptr2;
+ unsigned char *ptr;
char *sptr;
- OM_uint32 tmp;
- size_t md5len;
krb5_gss_cred_id_t cred = 0;
krb5_data ap_rep, ap_req;
- unsigned int i;
krb5_error_code code;
krb5_address addr, *paddr;
krb5_authenticator *authdat = 0;
- krb5_checksum reqcksum;
krb5_gss_name_t name = NULL;
krb5_ui_4 gss_flags = 0;
krb5_gss_ctx_id_rec *ctx = NULL;
@@ -451,8 +616,6 @@ kg_accept_krb5(minor_status, context_handle,
gss_buffer_desc token;
krb5_auth_context auth_context = NULL;
krb5_ticket * ticket = NULL;
- int option_id;
- krb5_data option;
const gss_OID_desc *mech_used = NULL;
OM_uint32 major_status = GSS_S_FAILURE;
OM_uint32 tmp_minor_status;
@@ -463,7 +626,6 @@ kg_accept_krb5(minor_status, context_handle,
krb5int_access kaccess;
int cred_rcache = 0;
int no_encap = 0;
- int token_deleg_flag = 0;
krb5_flags ap_req_options = 0;
krb5_enctype negotiated_etype;
krb5_authdata_context ad_context = NULL;
@@ -489,7 +651,6 @@ kg_accept_krb5(minor_status, context_handle,
output_token->length = 0;
output_token->value = NULL;
token.value = 0;
- reqcksum.contents = 0;
ap_req.data = 0;
ap_rep.data = 0;
@@ -654,195 +815,16 @@ kg_accept_krb5(minor_status, context_handle,
krb5_auth_con_getauthenticator(context, auth_context, &authdat);
- if (authdat->checksum == NULL) {
- /*
- * Some SMB client implementations use handcrafted GSSAPI code that
- * does not provide a checksum. MS-KILE documents that the Microsoft
- * implementation considers a missing checksum acceptable; the server
- * assumes all flags are unset in this case, and does not check channel
- * bindings.
- */
- gss_flags = 0;
- } else if (authdat->checksum->checksum_type != CKSUMTYPE_KG_CB) {
- /* Samba does not send 0x8003 GSS-API checksums */
- krb5_boolean valid;
- krb5_key subkey;
- krb5_data zero;
+ major_status = process_checksum(minor_status, context, input_chan_bindings,
+ auth_context, ap_req_options,
+ authdat, exts,
+ delegated_cred_handle ? &deleg_cred : NULL,
+ &gss_flags, &code);
- code = krb5_auth_con_getkey_k(context, auth_context, &subkey);
- if (code) {
- major_status = GSS_S_FAILURE;
- goto fail;
- }
+ if (major_status != GSS_S_COMPLETE)
+ goto fail;
- zero.length = 0;
- zero.data = "";
-
- code = krb5_k_verify_checksum(context,
- subkey,
- KRB5_KEYUSAGE_AP_REQ_AUTH_CKSUM,
- &zero,
- authdat->checksum,
- &valid);
- krb5_k_free_key(context, subkey);
- if (code || !valid) {
- major_status = GSS_S_BAD_SIG;
- goto fail;
- }
-
- /* Use ap_options from the request to guess the mutual flag. */
- gss_flags = GSS_C_REPLAY_FLAG | GSS_C_SEQUENCE_FLAG;
- if (ap_req_options & AP_OPTS_MUTUAL_REQUIRED)
- gss_flags |= GSS_C_MUTUAL_FLAG;
- } else {
- /* gss krb5 v1 */
-
- /* stash this now, for later. */
- code = krb5_c_checksum_length(context, CKSUMTYPE_RSA_MD5, &md5len);
- if (code) {
- major_status = GSS_S_FAILURE;
- goto fail;
- }
-
- /* verify that the checksum is correct */
-
- /*
- The checksum may be either exactly 24 bytes, in which case
- no options are specified, or greater than 24 bytes, in which case
- one or more options are specified. Currently, the only valid
- option is KRB5_GSS_FOR_CREDS_OPTION ( = 1 ).
- */
-
- if ((authdat->checksum->checksum_type != CKSUMTYPE_KG_CB) ||
- (authdat->checksum->length < 24)) {
- code = 0;
- major_status = GSS_S_BAD_BINDINGS;
- goto fail;
- }
-
- ptr = (unsigned char *) authdat->checksum->contents;
-
- TREAD_INT(ptr, tmp, 0);
-
- if (tmp != md5len) {
- code = KG_BAD_LENGTH;
- major_status = GSS_S_FAILURE;
- goto fail;
- }
-
- /*
- The following section of code attempts to implement the
- optional channel binding facility as described in RFC2743.
-
- Since this facility is optional channel binding may or may
- not have been provided by either the client or the server.
-
- If the server has specified input_chan_bindings equal to
- GSS_C_NO_CHANNEL_BINDINGS then we skip the check. If
- the server does provide channel bindings then we compute
- a checksum and compare against those provided by the
- client. */
-
- if ((code = kg_checksum_channel_bindings(context,
- input_chan_bindings,
- &reqcksum))) {
- major_status = GSS_S_BAD_BINDINGS;
- goto fail;
- }
-
- /* Always read the clients bindings - eventhough we might ignore them */
- TREAD_STR(ptr, ptr2, reqcksum.length);
-
- if (input_chan_bindings != GSS_C_NO_CHANNEL_BINDINGS ) {
- if (memcmp(ptr2, reqcksum.contents, reqcksum.length) != 0) {
- xfree(reqcksum.contents);
- reqcksum.contents = 0;
- code = 0;
- major_status = GSS_S_BAD_BINDINGS;
- goto fail;
- }
-
- }
-
- xfree(reqcksum.contents);
- reqcksum.contents = 0;
-
- /* Read the token flags. Remember if GSS_C_DELEG_FLAG was set, but
- * mask it out until we actually read a delegated credential. */
- TREAD_INT(ptr, gss_flags, 0);
- token_deleg_flag = (gss_flags & GSS_C_DELEG_FLAG);
- gss_flags &= ~GSS_C_DELEG_FLAG;
-
- /* if the checksum length > 24, there are options to process */
-
- i = authdat->checksum->length - 24;
- if (i && token_deleg_flag) {
- if (i >= 4) {
- TREAD_INT16(ptr, option_id, 0);
- TREAD_INT16(ptr, option.length, 0);
- i -= 4;
-
- if (i < option.length) {
- code = KG_BAD_LENGTH;
- major_status = GSS_S_FAILURE;
- goto fail;
- }
-
- /* have to use ptr2, since option.data is wrong type and
- macro uses ptr as both lvalue and rvalue */
-
- TREAD_STR(ptr, ptr2, option.length);
- option.data = (char *) ptr2;
-
- i -= option.length;
-
- if (option_id != KRB5_GSS_FOR_CREDS_OPTION) {
- major_status = GSS_S_FAILURE;
- goto fail;
- }
-
- /* store the delegated credential */
-
- code = rd_and_store_for_creds(context, auth_context, &option,
- (delegated_cred_handle) ?
- &deleg_cred : NULL);
- if (code) {
- major_status = GSS_S_FAILURE;
- goto fail;
- }
-
- gss_flags |= GSS_C_DELEG_FLAG;
- } /* if i >= 4 */
- /* ignore any additional trailing data, for now */
- }
- while (i > 0) {
- /* Process Type-Length-Data options */
- if (i < 8) {
- code = KG_BAD_LENGTH;
- major_status = GSS_S_FAILURE;
- goto fail;
- }
- TREAD_INT(ptr, option_id, 1);
- TREAD_INT(ptr, option.length, 1);
- i -= 8;
- if (i < option.length) {
- code = KG_BAD_LENGTH;
- major_status = GSS_S_FAILURE;
- goto fail;
- }
- TREAD_STR(ptr, ptr2, option.length);
- option.data = (char *)ptr2;
-
- i -= option.length;
-
- code = kg_process_extension(context, auth_context,
- option_id, &option, exts);
- if (code != 0) {
- major_status = GSS_S_FAILURE;
- goto fail;
- }
- }
- }
+ major_status = GSS_S_FAILURE;
if (exts->iakerb.conv && !exts->iakerb.verified) {
major_status = GSS_S_BAD_SIG;
@@ -869,12 +851,7 @@ kg_accept_krb5(minor_status, context_handle,
ctx->mech_used = (gss_OID) mech_used;
ctx->auth_context = auth_context;
ctx->initiate = 0;
- ctx->gss_flags = (GSS_C_TRANS_FLAG |
- ((gss_flags) & (GSS_C_INTEG_FLAG | GSS_C_CONF_FLAG |
- GSS_C_MUTUAL_FLAG | GSS_C_REPLAY_FLAG |
- GSS_C_SEQUENCE_FLAG | GSS_C_DELEG_FLAG |
- GSS_C_DCE_STYLE | GSS_C_IDENTIFY_FLAG |
- GSS_C_EXTENDED_ERROR_FLAG)));
+ ctx->gss_flags = gss_flags | GSS_C_TRANS_FLAG;
ctx->seed_init = 0;
ctx->cred_rcache = cred_rcache;
@@ -1161,8 +1138,6 @@ fail:
krb5_auth_con_free(context, auth_context);
}
- if (reqcksum.contents)
- xfree(reqcksum.contents);
if (ap_rep.data)
krb5_free_data_contents(context, &ap_rep);
if (major_status == GSS_S_COMPLETE ||

2
Remove-resolver-test-utility.patch
View File

@ -1,4 +1,4 @@
From c21bb26abc4799298726124d73f0c968430a87bd Mon Sep 17 00:00:00 2001
From 85bb5fe5a11708b78e9f0bd3a3b34999b6c888a7 Mon Sep 17 00:00:00 2001
From: Greg Hudson <ghudson@mit.edu>
Date: Thu, 28 May 2020 18:41:02 -0400
Subject: [PATCH] Remove resolver test utility

2
Replace-gssrpc-tests-with-a-Python-script.patch
View File

@ -1,4 +1,4 @@
From 5af211200d6c2ac82872435556f5b39edcaba541 Mon Sep 17 00:00:00 2001
From a12fc355a034e5b1d23bdb23db9735d4eaa396d8 Mon Sep 17 00:00:00 2001
From: Greg Hudson <ghudson@mit.edu>
Date: Sat, 15 Feb 2020 20:34:23 -0500
Subject: [PATCH] Replace gssrpc tests with a Python script

13
krb5.spec
View File

@ -18,7 +18,7 @@ Summary: The Kerberos network authentication system
Name: krb5
Version: 1.18.2
# for prerelease, should be e.g., 0.% {prerelease}.1% { ?dist } (without spaces)
Release: 7%{?dist}
Release: 8%{?dist}
# rharwood has trust path to signing key and verifies on check-in
Source0: https://web.mit.edu/kerberos/dist/krb5/1.18/krb5-%{version}%{prerelease}.tar.gz
@ -56,11 +56,17 @@ Patch16: Do-expiration-warnings-for-all-init_creds-APIs.patch
Patch17: Pass-gss_localname-through-SPNEGO.patch
Patch18: Omit-KDC-indicator-check-for-S4U2Self-requests.patch
Patch19: Fix-typo-in-in-in-the-ksu-man-page.patch
Patch20: Pass-channel-bindings-through-SPNEGO.patch
Patch21: Replace-gssrpc-tests-with-a-Python-script.patch
Patch22: Default-dns_canonicalize_hostname-to-fallback.patch
Patch23: Remove-resolver-test-utility.patch
Patch24: Omit-PA_FOR_USER-if-we-can-t-compute-its-checksum.patch
Patch25: Improve-negoex_parse_token-code-hygiene.patch
Patch26: Refactor-krb5-GSS-checksum-handling.patch
Patch27: Implement-GSS_C_CHANNEL_BOUND_FLAG.patch
Patch28: Implement-KERB_AP_OPTIONS_CBT-server-side.patch
Patch29: Add-client_aware_channel_bindings-option.patch
Patch30: Pass-channel-bindings-through-SPNEGO.patch
Patch31: Add-channel-bindings-tests.patch
License: MIT
URL: https://web.mit.edu/kerberos/www/
@ -615,6 +621,9 @@ exit 0
%{_libdir}/libkadm5srv_mit.so.*
%changelog
* Mon Jun 15 2020 Robbie Harwood <rharwood@redhat.com> - 1.18.2-8
- Match Heimdal behavior for channel bindings
* Mon Jun 08 2020 Robbie Harwood <rharwood@redhat.com> - 1.18.2-7
- Fix test suite by removing wrapper workarounds