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98c14205a0
Best reviewed with: `git show --word-diff` Signed-off-by: Andreas Schneider <asn@samba.org> Reviewed-by: Rowland Penny <rpenny@samba.org>
349 lines
10 KiB
C
349 lines
10 KiB
C
/*
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Unix SMB/CIFS implementation.
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kerberos authorization data (PAC) utility library
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Copyright (C) Andrew Bartlett <abartlet@samba.org> 2011
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Copyright (C) Simo Sorce 2010.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "includes.h"
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#undef DBGC_CLASS
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#define DBGC_CLASS DBGC_AUTH
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#ifdef HAVE_KRB5
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#include "auth/kerberos/pac_utils.h"
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#if 0
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/* FIXME - need proper configure/waf test
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* to determine if gss_mech_krb5 and friends
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* exist. JRA.
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*/
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/*
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* These are not exported by Solaris -lkrb5
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* Maybe move to libreplace somewhere?
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*/
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static const gss_OID_desc krb5_gss_oid_array[] = {
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/* this is the official, rfc-specified OID */
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{ 9, "\052\206\110\206\367\022\001\002\002" },
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/* this is the pre-RFC mech OID */
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{ 5, "\053\005\001\005\002" },
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/* this is the unofficial, incorrect mech OID emitted by MS */
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{ 9, "\052\206\110\202\367\022\001\002\002" },
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{ 0, 0 }
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};
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const gss_OID_desc * const gss_mech_krb5 = krb5_gss_oid_array+0;
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const gss_OID_desc * const gss_mech_krb5_old = krb5_gss_oid_array+1;
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const gss_OID_desc * const gss_mech_krb5_wrong = krb5_gss_oid_array+2;
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#endif
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#ifndef GSS_KRB5_INQ_SSPI_SESSION_KEY_OID
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#define GSS_KRB5_INQ_SSPI_SESSION_KEY_OID_LENGTH 11
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#define GSS_KRB5_INQ_SSPI_SESSION_KEY_OID "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02\x05\x05"
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#endif
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gss_OID_desc gse_sesskey_inq_oid = {
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GSS_KRB5_INQ_SSPI_SESSION_KEY_OID_LENGTH,
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discard_const(GSS_KRB5_INQ_SSPI_SESSION_KEY_OID)
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};
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#ifndef GSS_KRB5_SESSION_KEY_ENCTYPE_OID
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#define GSS_KRB5_SESSION_KEY_ENCTYPE_OID_LENGTH 10
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#define GSS_KRB5_SESSION_KEY_ENCTYPE_OID "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02\x04"
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#endif
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gss_OID_desc gse_sesskeytype_oid = {
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GSS_KRB5_SESSION_KEY_ENCTYPE_OID_LENGTH,
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discard_const(GSS_KRB5_SESSION_KEY_ENCTYPE_OID)
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};
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/* The Heimdal OID for getting the PAC */
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#define EXTRACT_PAC_AUTHZ_DATA_FROM_SEC_CONTEXT_OID_LENGTH 8
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/* EXTRACTION OID AUTHZ ID */
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#define EXTRACT_PAC_AUTHZ_DATA_FROM_SEC_CONTEXT_OID "\x2a\x85\x70\x2b\x0d\x03" "\x81\x00"
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NTSTATUS gssapi_obtain_pac_blob(TALLOC_CTX *mem_ctx,
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gss_ctx_id_t gssapi_context,
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gss_name_t gss_client_name,
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DATA_BLOB *pac_blob)
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{
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NTSTATUS status;
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OM_uint32 gss_maj, gss_min;
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#ifdef HAVE_GSS_GET_NAME_ATTRIBUTE
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/*
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* gss_get_name_attribute() in MIT krb5 1.10.0 can return uninitialized pac_display_buffer
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* and later gss_release_buffer() will crash on attempting to release it.
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*
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* So always initialize the buffer descriptors.
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*
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* See following links for more details:
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* http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=658514
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* http://krbdev.mit.edu/rt/Ticket/Display.html?user=guest&pass=guest&id=7087
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*/
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gss_buffer_desc pac_buffer = {
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.value = NULL,
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.length = 0
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};
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gss_buffer_desc pac_display_buffer = {
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.value = NULL,
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.length = 0
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};
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gss_buffer_desc pac_name = {
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.value = discard_const("urn:mspac:"),
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.length = sizeof("urn:mspac:")-1
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};
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int more = -1;
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int authenticated = false;
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int complete = false;
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gss_maj = gss_get_name_attribute(
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&gss_min, gss_client_name, &pac_name,
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&authenticated, &complete,
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&pac_buffer, &pac_display_buffer, &more);
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if (gss_maj != 0) {
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gss_OID oid = discard_const(gss_mech_krb5);
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DBG_NOTICE("obtaining PAC via GSSAPI gss_get_name_attribute "
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"failed: %s\n", gssapi_error_string(mem_ctx,
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gss_maj, gss_min,
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oid));
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return NT_STATUS_ACCESS_DENIED;
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} else if (authenticated && complete) {
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/* The PAC blob is returned directly */
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*pac_blob = data_blob_talloc(mem_ctx, pac_buffer.value,
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pac_buffer.length);
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if (!pac_blob->data) {
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status = NT_STATUS_NO_MEMORY;
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} else {
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status = NT_STATUS_OK;
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}
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gss_release_buffer(&gss_min, &pac_buffer);
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gss_release_buffer(&gss_min, &pac_display_buffer);
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return status;
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} else {
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DEBUG(0, ("obtaining PAC via GSSAPI failed: authenticated: %s, complete: %s, more: %s\n",
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authenticated ? "true" : "false",
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complete ? "true" : "false",
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more ? "true" : "false"));
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return NT_STATUS_ACCESS_DENIED;
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}
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#elif defined(HAVE_GSS_INQUIRE_SEC_CONTEXT_BY_OID)
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gss_OID_desc pac_data_oid = {
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.elements = discard_const(EXTRACT_PAC_AUTHZ_DATA_FROM_SEC_CONTEXT_OID),
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.length = EXTRACT_PAC_AUTHZ_DATA_FROM_SEC_CONTEXT_OID_LENGTH
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};
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gss_buffer_set_t set = GSS_C_NO_BUFFER_SET;
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/* If we didn't have the routine to get a verified, validated
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* PAC (supplied only by MIT at the time of writing), then try
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* with the Heimdal OID (fetches the PAC directly and always
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* validates) */
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gss_maj = gss_inquire_sec_context_by_oid(
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&gss_min, gssapi_context,
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&pac_data_oid, &set);
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/* First check for the error MIT gives for an unknown OID */
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if (gss_maj == GSS_S_UNAVAILABLE) {
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DEBUG(1, ("unable to obtain a PAC against this GSSAPI library. "
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"GSSAPI secured connections are available only with Heimdal or MIT Kerberos >= 1.8\n"));
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} else if (gss_maj != 0) {
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DEBUG(2, ("obtaining PAC via GSSAPI gss_inquire_sec_context_by_oid (Heimdal OID) failed: %s\n",
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gssapi_error_string(mem_ctx, gss_maj, gss_min, gss_mech_krb5)));
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} else {
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if (set == GSS_C_NO_BUFFER_SET) {
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DEBUG(0, ("gss_inquire_sec_context_by_oid returned unknown "
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"data in results.\n"));
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return NT_STATUS_INTERNAL_ERROR;
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}
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/* The PAC blob is returned directly */
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*pac_blob = data_blob_talloc(mem_ctx, set->elements[0].value,
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set->elements[0].length);
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if (!pac_blob->data) {
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status = NT_STATUS_NO_MEMORY;
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} else {
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status = NT_STATUS_OK;
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}
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gss_maj = gss_release_buffer_set(&gss_min, &set);
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return status;
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}
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#else
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DEBUG(1, ("unable to obtain a PAC against this GSSAPI library. "
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"GSSAPI secured connections are available only with Heimdal or MIT Kerberos >= 1.8\n"));
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#endif
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return NT_STATUS_ACCESS_DENIED;
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}
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NTSTATUS gssapi_get_session_key(TALLOC_CTX *mem_ctx,
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gss_ctx_id_t gssapi_context,
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DATA_BLOB *session_key,
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uint32_t *keytype)
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{
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OM_uint32 gss_min, gss_maj;
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gss_buffer_set_t set = GSS_C_NO_BUFFER_SET;
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gss_maj = gss_inquire_sec_context_by_oid(
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&gss_min, gssapi_context,
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&gse_sesskey_inq_oid, &set);
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if (gss_maj) {
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DEBUG(0, ("gss_inquire_sec_context_by_oid failed [%s]\n",
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gssapi_error_string(mem_ctx,
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gss_maj,
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gss_min,
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discard_const_p(struct gss_OID_desc_struct,
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gss_mech_krb5))));
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return NT_STATUS_NO_USER_SESSION_KEY;
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}
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if ((set == GSS_C_NO_BUFFER_SET) ||
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(set->count == 0)) {
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#ifdef HAVE_GSSKRB5_GET_SUBKEY
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krb5_keyblock *subkey;
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gss_maj = gsskrb5_get_subkey(&gss_min,
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gssapi_context,
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&subkey);
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if (gss_maj != 0) {
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DEBUG(1, ("NO session key for this mech\n"));
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return NT_STATUS_NO_USER_SESSION_KEY;
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}
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if (session_key) {
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*session_key = data_blob_talloc(mem_ctx,
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KRB5_KEY_DATA(subkey), KRB5_KEY_LENGTH(subkey));
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}
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if (keytype) {
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*keytype = KRB5_KEY_TYPE(subkey);
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}
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krb5_free_keyblock(NULL /* should be krb5_context */, subkey);
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return NT_STATUS_OK;
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#else
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DEBUG(0, ("gss_inquire_sec_context_by_oid didn't return any session key (and no alternative method available)\n"));
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return NT_STATUS_NO_USER_SESSION_KEY;
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#endif
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}
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if (session_key) {
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*session_key = data_blob_talloc(mem_ctx, set->elements[0].value,
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set->elements[0].length);
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}
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if (keytype) {
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int diflen, i;
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const uint8_t *p;
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*keytype = 0;
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if (set->count < 2) {
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#ifdef HAVE_GSSKRB5_GET_SUBKEY
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krb5_keyblock *subkey;
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gss_maj = gsskrb5_get_subkey(&gss_min,
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gssapi_context,
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&subkey);
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if (gss_maj == 0) {
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*keytype = KRB5_KEY_TYPE(subkey);
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krb5_free_keyblock(NULL /* should be krb5_context */, subkey);
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}
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#endif
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gss_release_buffer_set(&gss_min, &set);
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return NT_STATUS_OK;
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} else if (memcmp(set->elements[1].value,
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gse_sesskeytype_oid.elements,
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gse_sesskeytype_oid.length) != 0) {
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/* Perhaps a non-krb5 session key */
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gss_release_buffer_set(&gss_min, &set);
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return NT_STATUS_OK;
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}
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p = (const uint8_t *)set->elements[1].value + gse_sesskeytype_oid.length;
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diflen = set->elements[1].length - gse_sesskeytype_oid.length;
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if (diflen <= 0) {
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gss_release_buffer_set(&gss_min, &set);
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return NT_STATUS_INVALID_PARAMETER;
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}
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for (i = 0; i < diflen; i++) {
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*keytype = (*keytype << 7) | (p[i] & 0x7f);
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if (i + 1 != diflen && (p[i] & 0x80) == 0) {
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gss_release_buffer_set(&gss_min, &set);
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return NT_STATUS_INVALID_PARAMETER;
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}
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}
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}
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gss_release_buffer_set(&gss_min, &set);
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return NT_STATUS_OK;
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}
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char *gssapi_error_string(TALLOC_CTX *mem_ctx,
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OM_uint32 maj_stat, OM_uint32 min_stat,
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const gss_OID mech)
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{
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OM_uint32 disp_min_stat, disp_maj_stat;
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gss_buffer_desc maj_error_message;
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gss_buffer_desc min_error_message;
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char *maj_error_string, *min_error_string;
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OM_uint32 msg_ctx = 0;
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char *ret;
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maj_error_message.value = NULL;
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min_error_message.value = NULL;
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maj_error_message.length = 0;
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min_error_message.length = 0;
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disp_maj_stat = gss_display_status(&disp_min_stat, maj_stat,
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GSS_C_GSS_CODE, mech,
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&msg_ctx, &maj_error_message);
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if (disp_maj_stat != 0) {
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maj_error_message.value = NULL;
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maj_error_message.length = 0;
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}
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disp_maj_stat = gss_display_status(&disp_min_stat, min_stat,
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GSS_C_MECH_CODE, mech,
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&msg_ctx, &min_error_message);
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if (disp_maj_stat != 0) {
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min_error_message.value = NULL;
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min_error_message.length = 0;
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}
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maj_error_string = talloc_strndup(mem_ctx,
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(char *)maj_error_message.value,
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maj_error_message.length);
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min_error_string = talloc_strndup(mem_ctx,
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(char *)min_error_message.value,
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min_error_message.length);
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ret = talloc_asprintf(mem_ctx, "%s: %s",
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maj_error_string, min_error_string);
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talloc_free(maj_error_string);
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talloc_free(min_error_string);
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gss_release_buffer(&disp_min_stat, &maj_error_message);
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gss_release_buffer(&disp_min_stat, &min_error_message);
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return ret;
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}
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#endif /* HAVE_KRB5 */
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