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samba-mirror/source3/libads/sasl.c

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/*
Unix SMB/CIFS implementation.
ads sasl code
Copyright (C) Andrew Tridgell 2001
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
#ifdef HAVE_LDAP
/*
perform a LDAP/SASL/SPNEGO/NTLMSSP bind (just how many layers can
we fit on one socket??)
*/
static ADS_STATUS ads_sasl_spnego_ntlmssp_bind(ADS_STRUCT *ads)
{
DATA_BLOB msg1 = data_blob(NULL, 0);
DATA_BLOB blob = data_blob(NULL, 0);
DATA_BLOB blob_in = data_blob(NULL, 0);
DATA_BLOB blob_out = data_blob(NULL, 0);
struct berval cred, *scred = NULL;
int rc;
NTSTATUS nt_status;
int turn = 1;
struct ntlmssp_state *ntlmssp_state;
if (!NT_STATUS_IS_OK(nt_status = ntlmssp_client_start(&ntlmssp_state))) {
return ADS_ERROR_NT(nt_status);
}
if (!NT_STATUS_IS_OK(nt_status = ntlmssp_set_username(ntlmssp_state, ads->auth.user_name))) {
return ADS_ERROR_NT(nt_status);
}
if (!NT_STATUS_IS_OK(nt_status = ntlmssp_set_domain(ntlmssp_state, ads->auth.realm))) {
return ADS_ERROR_NT(nt_status);
}
if (!NT_STATUS_IS_OK(nt_status = ntlmssp_set_password(ntlmssp_state, ads->auth.password))) {
return ADS_ERROR_NT(nt_status);
}
blob_in = data_blob(NULL, 0);
do {
nt_status = ntlmssp_update(ntlmssp_state,
blob_in, &blob_out);
data_blob_free(&blob_in);
if ((NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)
|| NT_STATUS_IS_OK(nt_status))
&& blob_out.length) {
if (turn == 1) {
/* and wrap it in a SPNEGO wrapper */
msg1 = gen_negTokenInit(OID_NTLMSSP, blob_out);
} else {
/* wrap it in SPNEGO */
msg1 = spnego_gen_auth(blob_out);
}
data_blob_free(&blob_out);
cred.bv_val = (char *)msg1.data;
cred.bv_len = msg1.length;
scred = NULL;
rc = ldap_sasl_bind_s(ads->ld, NULL, "GSS-SPNEGO", &cred, NULL, NULL, &scred);
data_blob_free(&msg1);
if ((rc != LDAP_SASL_BIND_IN_PROGRESS) && (rc != 0)) {
if (scred) {
ber_bvfree(scred);
}
ntlmssp_end(&ntlmssp_state);
return ADS_ERROR(rc);
}
if (scred) {
blob = data_blob(scred->bv_val, scred->bv_len);
ber_bvfree(scred);
} else {
blob = data_blob(NULL, 0);
}
} else {
ntlmssp_end(&ntlmssp_state);
data_blob_free(&blob_out);
return ADS_ERROR_NT(nt_status);
}
if ((turn == 1) &&
(rc == LDAP_SASL_BIND_IN_PROGRESS)) {
DATA_BLOB tmp_blob = data_blob(NULL, 0);
/* the server might give us back two challenges */
if (!spnego_parse_challenge(blob, &blob_in,
&tmp_blob)) {
ntlmssp_end(&ntlmssp_state);
data_blob_free(&blob);
DEBUG(3,("Failed to parse challenges\n"));
return ADS_ERROR_NT(NT_STATUS_INVALID_PARAMETER);
}
data_blob_free(&tmp_blob);
} else if (rc == LDAP_SASL_BIND_IN_PROGRESS) {
if (!spnego_parse_auth_response(blob, nt_status,
&blob_in)) {
ntlmssp_end(&ntlmssp_state);
data_blob_free(&blob);
DEBUG(3,("Failed to parse auth response\n"));
return ADS_ERROR_NT(NT_STATUS_INVALID_PARAMETER);
}
}
data_blob_free(&blob);
data_blob_free(&blob_out);
turn++;
} while (rc == LDAP_SASL_BIND_IN_PROGRESS && !NT_STATUS_IS_OK(nt_status));
/* we have a reference conter on ntlmssp_state, if we are signing
then the state will be kept by the signing engine */
ntlmssp_end(&ntlmssp_state);
return ADS_ERROR(rc);
}
#ifdef HAVE_KRB5
/*
perform a LDAP/SASL/SPNEGO/KRB5 bind
*/
static ADS_STATUS ads_sasl_spnego_krb5_bind(ADS_STRUCT *ads, const char *principal)
{
DATA_BLOB blob = data_blob(NULL, 0);
struct berval cred, *scred = NULL;
DATA_BLOB session_key = data_blob(NULL, 0);
int rc;
rc = spnego_gen_negTokenTarg(principal, ads->auth.time_offset, &blob, &session_key, 0);
if (rc) {
return ADS_ERROR_KRB5(rc);
}
/* now send the auth packet and we should be done */
cred.bv_val = (char *)blob.data;
cred.bv_len = blob.length;
rc = ldap_sasl_bind_s(ads->ld, NULL, "GSS-SPNEGO", &cred, NULL, NULL, &scred);
data_blob_free(&blob);
data_blob_free(&session_key);
if(scred)
ber_bvfree(scred);
return ADS_ERROR(rc);
}
#endif
/*
this performs a SASL/SPNEGO bind
*/
static ADS_STATUS ads_sasl_spnego_bind(ADS_STRUCT *ads)
{
struct berval *scred=NULL;
int rc, i;
ADS_STATUS status;
DATA_BLOB blob;
char *principal = NULL;
char *OIDs[ASN1_MAX_OIDS];
#ifdef HAVE_KRB5
BOOL got_kerberos_mechanism = False;
#endif
rc = ldap_sasl_bind_s(ads->ld, NULL, "GSS-SPNEGO", NULL, NULL, NULL, &scred);
if (rc != LDAP_SASL_BIND_IN_PROGRESS) {
status = ADS_ERROR(rc);
goto failed;
}
blob = data_blob(scred->bv_val, scred->bv_len);
ber_bvfree(scred);
#if 0
file_save("sasl_spnego.dat", blob.data, blob.length);
#endif
/* the server sent us the first part of the SPNEGO exchange in the negprot
reply */
if (!spnego_parse_negTokenInit(blob, OIDs, &principal)) {
data_blob_free(&blob);
status = ADS_ERROR(LDAP_OPERATIONS_ERROR);
goto failed;
}
data_blob_free(&blob);
/* make sure the server understands kerberos */
for (i=0;OIDs[i];i++) {
DEBUG(3,("ads_sasl_spnego_bind: got OID=%s\n", OIDs[i]));
#ifdef HAVE_KRB5
if (strcmp(OIDs[i], OID_KERBEROS5_OLD) == 0 ||
strcmp(OIDs[i], OID_KERBEROS5) == 0) {
got_kerberos_mechanism = True;
}
#endif
free(OIDs[i]);
}
DEBUG(3,("ads_sasl_spnego_bind: got server principal name =%s\n", principal));
#ifdef HAVE_KRB5
if (!(ads->auth.flags & ADS_AUTH_DISABLE_KERBEROS) &&
got_kerberos_mechanism) {
status = ads_sasl_spnego_krb5_bind(ads, principal);
if (ADS_ERR_OK(status)) {
SAFE_FREE(principal);
return status;
}
status = ADS_ERROR_KRB5(ads_kinit_password(ads));
if (ADS_ERR_OK(status)) {
status = ads_sasl_spnego_krb5_bind(ads, principal);
}
/* only fallback to NTLMSSP if allowed */
if (ADS_ERR_OK(status) ||
!(ads->auth.flags & ADS_AUTH_ALLOW_NTLMSSP)) {
SAFE_FREE(principal);
return status;
}
}
#endif
SAFE_FREE(principal);
/* lets do NTLMSSP ... this has the big advantage that we don't need
to sync clocks, and we don't rely on special versions of the krb5
library for HMAC_MD4 encryption */
return ads_sasl_spnego_ntlmssp_bind(ads);
failed:
return status;
}
#ifdef HAVE_GSSAPI
#define MAX_GSS_PASSES 3
/* this performs a SASL/gssapi bind
we avoid using cyrus-sasl to make Samba more robust. cyrus-sasl
is very dependent on correctly configured DNS whereas
this routine is much less fragile
see RFC2078 and RFC2222 for details
*/
static ADS_STATUS ads_sasl_gssapi_bind(ADS_STRUCT *ads)
{
uint32 minor_status;
gss_name_t serv_name;
gss_buffer_desc input_name;
gss_ctx_id_t context_handle;
gss_OID mech_type = GSS_C_NULL_OID;
gss_buffer_desc output_token, input_token;
uint32 ret_flags, conf_state;
struct berval cred;
struct berval *scred = NULL;
int i=0;
int gss_rc, rc;
uint8 *p;
uint32 max_msg_size = 0;
char *sname;
ADS_STATUS status;
krb5_principal principal;
krb5_context ctx = NULL;
gss_OID_desc nt_principal =
{10, CONST_DISCARD(char *, "\052\206\110\206\367\022\001\002\002\002")};
/* we need to fetch a service ticket as the ldap user in the
servers realm, regardless of our realm */
asprintf(&sname, "ldap/%s@%s", ads->config.ldap_server_name, ads->config.realm);
initialize_krb5_error_table();
status = ADS_ERROR_KRB5(krb5_init_context(&ctx));
if (!ADS_ERR_OK(status)) {
return status;
}
status = ADS_ERROR_KRB5(smb_krb5_parse_name(ctx, sname, &principal));
if (!ADS_ERR_OK(status)) {
return status;
}
free(sname);
krb5_free_context(ctx);
input_name.value = &principal;
input_name.length = sizeof(principal);
gss_rc = gss_import_name(&minor_status, &input_name, &nt_principal, &serv_name);
if (gss_rc) {
return ADS_ERROR_GSS(gss_rc, minor_status);
}
context_handle = GSS_C_NO_CONTEXT;
input_token.value = NULL;
input_token.length = 0;
for (i=0; i < MAX_GSS_PASSES; i++) {
gss_rc = gss_init_sec_context(&minor_status,
GSS_C_NO_CREDENTIAL,
&context_handle,
serv_name,
mech_type,
GSS_C_MUTUAL_FLAG | GSS_C_REPLAY_FLAG,
0,
NULL,
&input_token,
NULL,
&output_token,
&ret_flags,
NULL);
if (input_token.value) {
gss_release_buffer(&minor_status, &input_token);
}
if (gss_rc && gss_rc != GSS_S_CONTINUE_NEEDED) {
status = ADS_ERROR_GSS(gss_rc, minor_status);
goto failed;
}
cred.bv_val = (char *)output_token.value;
cred.bv_len = output_token.length;
rc = ldap_sasl_bind_s(ads->ld, NULL, "GSSAPI", &cred, NULL, NULL,
&scred);
if (rc != LDAP_SASL_BIND_IN_PROGRESS) {
status = ADS_ERROR(rc);
goto failed;
}
if (output_token.value) {
gss_release_buffer(&minor_status, &output_token);
}
if (scred) {
input_token.value = scred->bv_val;
input_token.length = scred->bv_len;
} else {
input_token.value = NULL;
input_token.length = 0;
}
if (gss_rc == 0) break;
}
gss_release_name(&minor_status, &serv_name);
gss_rc = gss_unwrap(&minor_status,context_handle,&input_token,&output_token,
(int *)&conf_state,NULL);
if (gss_rc) {
status = ADS_ERROR_GSS(gss_rc, minor_status);
goto failed;
}
gss_release_buffer(&minor_status, &input_token);
p = (uint8 *)output_token.value;
#if 0
file_save("sasl_gssapi.dat", output_token.value, output_token.length);
#endif
if (p) {
max_msg_size = (p[1]<<16) | (p[2]<<8) | p[3];
}
gss_release_buffer(&minor_status, &output_token);
output_token.value = SMB_MALLOC(strlen(ads->config.bind_path) + 8);
p = (uint8 *)output_token.value;
*p++ = 1; /* no sign & seal selection */
/* choose the same size as the server gave us */
*p++ = max_msg_size>>16;
*p++ = max_msg_size>>8;
*p++ = max_msg_size;
snprintf((char *)p, strlen(ads->config.bind_path)+4, "dn:%s", ads->config.bind_path);
p += strlen((const char *)p);
output_token.length = PTR_DIFF(p, output_token.value);
gss_rc = gss_wrap(&minor_status, context_handle,0,GSS_C_QOP_DEFAULT,
&output_token, (int *)&conf_state,
&input_token);
if (gss_rc) {
status = ADS_ERROR_GSS(gss_rc, minor_status);
goto failed;
}
free(output_token.value);
cred.bv_val = (char *)input_token.value;
cred.bv_len = input_token.length;
rc = ldap_sasl_bind_s(ads->ld, NULL, "GSSAPI", &cred, NULL, NULL,
&scred);
status = ADS_ERROR(rc);
gss_release_buffer(&minor_status, &input_token);
failed:
if(scred)
ber_bvfree(scred);
return status;
}
#endif /* HAVE_GGSAPI */
/* mapping between SASL mechanisms and functions */
static struct {
const char *name;
ADS_STATUS (*fn)(ADS_STRUCT *);
} sasl_mechanisms[] = {
{"GSS-SPNEGO", ads_sasl_spnego_bind},
#ifdef HAVE_GSSAPI
{"GSSAPI", ads_sasl_gssapi_bind}, /* doesn't work with .NET RC1. No idea why */
#endif
{NULL, NULL}
};
ADS_STATUS ads_sasl_bind(ADS_STRUCT *ads)
{
const char *attrs[] = {"supportedSASLMechanisms", NULL};
char **values;
ADS_STATUS status;
int i, j;
LDAPMessage *res;
/* get a list of supported SASL mechanisms */
status = ads_do_search(ads, "", LDAP_SCOPE_BASE, "(objectclass=*)", attrs, &res);
if (!ADS_ERR_OK(status)) return status;
values = ldap_get_values(ads->ld, res, "supportedSASLMechanisms");
/* try our supported mechanisms in order */
for (i=0;sasl_mechanisms[i].name;i++) {
/* see if the server supports it */
for (j=0;values && values[j];j++) {
if (strcmp(values[j], sasl_mechanisms[i].name) == 0) {
DEBUG(4,("Found SASL mechanism %s\n", values[j]));
status = sasl_mechanisms[i].fn(ads);
ldap_value_free(values);
ldap_msgfree(res);
return status;
}
}
}
ldap_value_free(values);
ldap_msgfree(res);
return ADS_ERROR(LDAP_AUTH_METHOD_NOT_SUPPORTED);
}
#endif /* HAVE_LDAP */