Exemple #1
0
 krb5_error_code kinit_to_ccache(TALLOC_CTX *parent_ctx,
				 struct cli_credentials *credentials,
				 struct smb_krb5_context *smb_krb5_context,
				 struct tevent_context *event_ctx,
				 krb5_ccache ccache,
				 enum credentials_obtained *obtained,
				 const char **error_string)
{
	krb5_error_code ret;
	const char *password;
#ifdef SAMBA4_USES_HEIMDAL
	const char *self_service;
#endif
	const char *target_service;
	time_t kdc_time = 0;
	krb5_principal princ;
	krb5_principal impersonate_principal;
	int tries;
	TALLOC_CTX *mem_ctx = talloc_new(parent_ctx);
	krb5_get_init_creds_opt *krb_options;

	if (!mem_ctx) {
		(*error_string) = strerror(ENOMEM);
		return ENOMEM;
	}

	ret = principal_from_credentials(mem_ctx, credentials, smb_krb5_context, &princ, obtained, error_string);
	if (ret) {
		talloc_free(mem_ctx);
		return ret;
	}

	if (princ == NULL) {
		(*error_string) = talloc_asprintf(credentials, "principal, username or realm was not specified in the credentials");
		talloc_free(mem_ctx);
		return KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
	}

	ret = impersonate_principal_from_credentials(mem_ctx, credentials, smb_krb5_context, &impersonate_principal, error_string);
	if (ret) {
		talloc_free(mem_ctx);
		return ret;
	}

#ifdef SAMBA4_USES_HEIMDAL
	self_service = cli_credentials_get_self_service(credentials);
#endif
	target_service = cli_credentials_get_target_service(credentials);

	password = cli_credentials_get_password(credentials);

	/* setup the krb5 options we want */
	if ((ret = krb5_get_init_creds_opt_alloc(smb_krb5_context->krb5_context, &krb_options))) {
		(*error_string) = talloc_asprintf(credentials, "krb5_get_init_creds_opt_alloc failed (%s)\n",
						  smb_get_krb5_error_message(smb_krb5_context->krb5_context,
									     ret, mem_ctx));
		talloc_free(mem_ctx);
		return ret;
	}

#ifdef SAMBA4_USES_HEIMDAL /* Disable for now MIT reads defaults when needed */
	/* get the defaults */
	krb5_get_init_creds_opt_set_default_flags(smb_krb5_context->krb5_context, NULL, NULL, krb_options);
#endif
	/* set if we want a forwardable ticket */
	switch (cli_credentials_get_krb_forwardable(credentials)) {
	case CRED_AUTO_KRB_FORWARDABLE:
		break;
	case CRED_NO_KRB_FORWARDABLE:
		krb5_get_init_creds_opt_set_forwardable(krb_options, FALSE);
		break;
	case CRED_FORCE_KRB_FORWARDABLE:
		krb5_get_init_creds_opt_set_forwardable(krb_options, TRUE);
		break;
	}

#ifdef SAMBA4_USES_HEIMDAL /* FIXME: MIT does not have this yet */
	/*
	 * In order to work against windows KDCs even if we use
	 * the netbios domain name as realm, we need to add the following
	 * flags:
	 * KRB5_INIT_CREDS_NO_C_CANON_CHECK;
	 * KRB5_INIT_CREDS_NO_C_NO_EKU_CHECK;
	 *
	 * On MIT: Set pkinit_eku_checking to none
	 */
	krb5_get_init_creds_opt_set_win2k(smb_krb5_context->krb5_context,
					  krb_options, true);
#else /* MIT */
	krb5_get_init_creds_opt_set_canonicalize(krb_options, true);
#endif

	tries = 2;
	while (tries--) {
#ifdef SAMBA4_USES_HEIMDAL
		struct tevent_context *previous_ev;
		/* Do this every time, in case we have weird recursive issues here */
		ret = smb_krb5_context_set_event_ctx(smb_krb5_context, event_ctx, &previous_ev);
		if (ret) {
			talloc_free(mem_ctx);
			return ret;
		}
#endif
		if (password) {
			if (impersonate_principal) {
#ifdef SAMBA4_USES_HEIMDAL
				ret = kerberos_kinit_s4u2_cc(
						smb_krb5_context->krb5_context,
						ccache, princ, password,
						impersonate_principal,
						self_service, target_service,
						krb_options, NULL, &kdc_time);
#else
				talloc_free(mem_ctx);
				(*error_string) = "INTERNAL error: s4u2 ops "
					"are not supported with MIT build yet";
				return EINVAL;
#endif
			} else {
				ret = kerberos_kinit_password_cc(
						smb_krb5_context->krb5_context,
						ccache, princ, password,
						target_service,
						krb_options, NULL, &kdc_time);
			}
		} else if (impersonate_principal) {
			talloc_free(mem_ctx);
			(*error_string) = "INTERNAL error: Cannot impersonate principal with just a keyblock.  A password must be specified in the credentials";
			return EINVAL;
		} else {
			/* No password available, try to use a keyblock instead */
			
			krb5_keyblock keyblock;
			const struct samr_Password *mach_pwd;
			mach_pwd = cli_credentials_get_nt_hash(credentials, mem_ctx);
			if (!mach_pwd) {
				talloc_free(mem_ctx);
				(*error_string) = "kinit_to_ccache: No password available for kinit\n";
				krb5_get_init_creds_opt_free(smb_krb5_context->krb5_context, krb_options);
#ifdef SAMBA4_USES_HEIMDAL
				smb_krb5_context_remove_event_ctx(smb_krb5_context, previous_ev, event_ctx);
#endif
				return EINVAL;
			}
			ret = smb_krb5_keyblock_init_contents(smb_krb5_context->krb5_context,
						 ENCTYPE_ARCFOUR_HMAC,
						 mach_pwd->hash, sizeof(mach_pwd->hash), 
						 &keyblock);
			
			if (ret == 0) {
				ret = kerberos_kinit_keyblock_cc(smb_krb5_context->krb5_context, ccache, 
								 princ, &keyblock,
								 target_service, krb_options,
								 NULL, &kdc_time);
				krb5_free_keyblock_contents(smb_krb5_context->krb5_context, &keyblock);
			}
		}

#ifdef SAMBA4_USES_HEIMDAL
		smb_krb5_context_remove_event_ctx(smb_krb5_context, previous_ev, event_ctx);
#endif

		if (ret == KRB5KRB_AP_ERR_SKEW || ret == KRB5_KDCREP_SKEW) {
			/* Perhaps we have been given an invalid skew, so try again without it */
			time_t t = time(NULL);
			krb5_set_real_time(smb_krb5_context->krb5_context, t, 0);
		} else {
			/* not a skew problem */
			break;
		}
	}

	krb5_get_init_creds_opt_free(smb_krb5_context->krb5_context, krb_options);

	if (ret == KRB5KRB_AP_ERR_SKEW || ret == KRB5_KDCREP_SKEW) {
		(*error_string) = talloc_asprintf(credentials, "kinit for %s failed (%s)\n",
						  cli_credentials_get_principal(credentials, mem_ctx),
						  smb_get_krb5_error_message(smb_krb5_context->krb5_context,
									     ret, mem_ctx));
		talloc_free(mem_ctx);
		return ret;
	}

	/* cope with ticket being in the future due to clock skew */
	if ((unsigned)kdc_time > time(NULL)) {
		time_t t = time(NULL);
		int time_offset =(unsigned)kdc_time-t;
		DEBUG(4,("Advancing clock by %d seconds to cope with clock skew\n", time_offset));
		krb5_set_real_time(smb_krb5_context->krb5_context, t + time_offset + 1, 0);
	}
	
	if (ret == KRB5KDC_ERR_PREAUTH_FAILED && cli_credentials_wrong_password(credentials)) {
		ret = kinit_to_ccache(parent_ctx,
				      credentials,
				      smb_krb5_context,
				      event_ctx,
				      ccache, obtained,
				      error_string);
	}

	if (ret) {
		(*error_string) = talloc_asprintf(credentials, "kinit for %s failed (%s)\n",
						  cli_credentials_get_principal(credentials, mem_ctx),
						  smb_get_krb5_error_message(smb_krb5_context->krb5_context,
									     ret, mem_ctx));
		talloc_free(mem_ctx);
		return ret;
	}

	DEBUG(10,("kinit for %s succeeded\n",
		cli_credentials_get_principal(credentials, mem_ctx)));


	talloc_free(mem_ctx);
	return 0;
}
Exemple #2
0
_PUBLIC_ int cli_credentials_get_server_gss_creds(struct cli_credentials *cred, 
						  struct loadparm_context *lp_ctx,
						  struct gssapi_creds_container **_gcc)
{
	int ret = 0;
	OM_uint32 maj_stat, min_stat;
	struct gssapi_creds_container *gcc;
	struct keytab_container *ktc;
	struct smb_krb5_context *smb_krb5_context;
	TALLOC_CTX *mem_ctx;
	krb5_principal princ;
	const char *error_string;
	enum credentials_obtained obtained;

	mem_ctx = talloc_new(cred);
	if (!mem_ctx) {
		return ENOMEM;
	}

	ret = cli_credentials_get_krb5_context(cred, lp_ctx, &smb_krb5_context);
	if (ret) {
		return ret;
	}

	ret = principal_from_credentials(mem_ctx, cred, smb_krb5_context, &princ, &obtained, &error_string);
	if (ret) {
		DEBUG(1,("cli_credentials_get_server_gss_creds: making krb5 principal failed (%s)\n",
			 error_string));
		talloc_free(mem_ctx);
		return ret;
	}

	if (cred->server_gss_creds_obtained >= (MAX(cred->keytab_obtained, obtained))) {
		talloc_free(mem_ctx);
		*_gcc = cred->server_gss_creds;
		return 0;
	}

	ret = cli_credentials_get_keytab(cred, lp_ctx, &ktc);
	if (ret) {
		DEBUG(1, ("Failed to get keytab for GSSAPI server: %s\n", error_message(ret)));
		return ret;
	}

	gcc = talloc(cred, struct gssapi_creds_container);
	if (!gcc) {
		talloc_free(mem_ctx);
		return ENOMEM;
	}

	if (ktc->password_based || obtained < CRED_SPECIFIED) {
		/* This creates a GSSAPI cred_id_t for match-by-key with only the keytab set */
		maj_stat = gss_krb5_import_cred(&min_stat, NULL, NULL, ktc->keytab,
						&gcc->creds);
	} else {
		/* This creates a GSSAPI cred_id_t with the principal and keytab set, matching by name */
		maj_stat = gss_krb5_import_cred(&min_stat, NULL, princ, ktc->keytab,
						&gcc->creds);
	}
	if (maj_stat) {
		if (min_stat) {
			ret = min_stat;
		} else {
			ret = EINVAL;
		}
	}
	if (ret == 0) {
		cred->server_gss_creds_obtained = cred->keytab_obtained;
		talloc_set_destructor(gcc, free_gssapi_creds);
		cred->server_gss_creds = gcc;
		*_gcc = gcc;
	}
	talloc_free(mem_ctx);
	return ret;
}
Exemple #3
0
static bool torture_krb5_as_req_creds(struct torture_context *tctx,
				      struct cli_credentials *credentials,
				      enum torture_krb5_test test)
{
	krb5_error_code k5ret;
	bool ok;
	krb5_creds my_creds;
	krb5_principal principal;
	struct smb_krb5_context *smb_krb5_context;
	enum credentials_obtained obtained;
	const char *error_string;
	const char *password = cli_credentials_get_password(credentials);
	krb5_get_init_creds_opt *krb_options = NULL;
	
	ok = torture_krb5_init_context(tctx, test, &smb_krb5_context);
	torture_assert(tctx, ok, "torture_krb5_init_context failed");
	
	k5ret = principal_from_credentials(tctx, credentials, smb_krb5_context,
					   &principal, &obtained,  &error_string);
	torture_assert_int_equal(tctx, k5ret, 0, error_string);

	switch (test)
	{
	case TORTURE_KRB5_TEST_PLAIN:
		break;

	case TORTURE_KRB5_TEST_PAC_REQUEST:
		torture_assert_int_equal(tctx,
					 krb5_get_init_creds_opt_alloc(smb_krb5_context->krb5_context, &krb_options),
					 0, "krb5_get_init_creds_opt_alloc failed");
		
		torture_assert_int_equal(tctx,
					 krb5_get_init_creds_opt_set_pac_request(smb_krb5_context->krb5_context, krb_options, true),
					 0, "krb5_get_init_creds_opt_set_pac_request failed");
		break;
		
	case TORTURE_KRB5_TEST_BREAK_PW:
		password = "******";
		break;

	case TORTURE_KRB5_TEST_CLOCK_SKEW:
		torture_assert_int_equal(tctx,
					 krb5_set_real_time(smb_krb5_context->krb5_context, time(NULL) + 3600, 0),
					 0, "krb5_set_real_time failed");
		break;

	break;
	}
	k5ret = krb5_get_init_creds_password(smb_krb5_context->krb5_context, &my_creds, principal,
					     password, NULL, NULL, 0,
					     NULL, krb_options);
	krb5_get_init_creds_opt_free(smb_krb5_context->krb5_context, krb_options);
	
	switch (test)
	{
	case TORTURE_KRB5_TEST_PLAIN:
	case TORTURE_KRB5_TEST_PAC_REQUEST:
		torture_assert_int_equal(tctx, k5ret, 0, "krb5_get_init_creds_password failed");
		break;

	case TORTURE_KRB5_TEST_BREAK_PW:
		torture_assert_int_equal(tctx, k5ret, KRB5KDC_ERR_PREAUTH_FAILED, "krb5_get_init_creds_password should have failed");
		return true;

	case TORTURE_KRB5_TEST_CLOCK_SKEW:
		torture_assert_int_equal(tctx, k5ret, KRB5KRB_AP_ERR_SKEW, "krb5_get_init_creds_password should have failed");
		return true;

	}

	k5ret = krb5_free_cred_contents(smb_krb5_context->krb5_context, &my_creds);
	torture_assert_int_equal(tctx, k5ret, 0, "krb5_free_creds failed");

	return true;
}
int cli_credentials_get_server_gss_creds(struct cli_credentials *cred, 
					 struct gssapi_creds_container **_gcc) 
{
	int ret = 0;
	OM_uint32 maj_stat, min_stat;
	struct gssapi_creds_container *gcc;
	struct keytab_container *ktc;
	struct smb_krb5_context *smb_krb5_context;
	TALLOC_CTX *mem_ctx;
	krb5_principal princ;

	if (cred->server_gss_creds_obtained >= (MAX(cred->keytab_obtained, 
						    MAX(cred->principal_obtained, 
							cred->username_obtained)))) {
		*_gcc = cred->server_gss_creds;
		return 0;
	}

	ret = cli_credentials_get_krb5_context(cred, &smb_krb5_context);
	if (ret) {
		return ret;
	}

	ret = cli_credentials_get_keytab(cred, 
					 &ktc);
	if (ret) {
		DEBUG(1, ("Failed to get keytab for GSSAPI server: %s\n", error_message(ret)));
		return ret;
	}

	mem_ctx = talloc_new(cred);
	if (!mem_ctx) {
		return ENOMEM;
	}

	ret = principal_from_credentials(mem_ctx, cred, smb_krb5_context, &princ);
	if (ret) {
		DEBUG(1,("cli_credentials_get_server_gss_creds: makeing krb5 principal failed (%s)\n",
			 smb_get_krb5_error_message(smb_krb5_context->krb5_context, 
						    ret, mem_ctx)));
		talloc_free(mem_ctx);
		return ret;
	}

	gcc = talloc(cred, struct gssapi_creds_container);
	if (!gcc) {
		talloc_free(mem_ctx);
		return ENOMEM;
	}

	/* This creates a GSSAPI cred_id_t with the principal and keytab set */
	maj_stat = gss_krb5_import_cred(&min_stat, NULL, princ, ktc->keytab, 
					&gcc->creds);
	if (maj_stat) {
		if (min_stat) {
			ret = min_stat;
		} else {
			ret = EINVAL;
		}
	}
	if (ret == 0) {
		cred->server_gss_creds_obtained = cred->keytab_obtained;
		talloc_set_destructor(gcc, free_gssapi_creds);
		cred->server_gss_creds = gcc;
		*_gcc = gcc;
	}
	talloc_free(mem_ctx);
	return ret;
}
 krb5_error_code kinit_to_ccache(TALLOC_CTX *parent_ctx,
				 struct cli_credentials *credentials,
				 struct smb_krb5_context *smb_krb5_context,
				 krb5_ccache ccache) 
{
	krb5_error_code ret;
	const char *password;
	time_t kdc_time = 0;
	krb5_principal princ;
	int tries;
	TALLOC_CTX *mem_ctx = talloc_new(parent_ctx);

	if (!mem_ctx) {
		return ENOMEM;
	}

	ret = principal_from_credentials(mem_ctx, credentials, smb_krb5_context, &princ);
	if (ret) {
		talloc_free(mem_ctx);
		return ret;
	}

	password = cli_credentials_get_password(credentials);

	tries = 2;
	while (tries--) {
		if (password) {
			ret = kerberos_kinit_password_cc(smb_krb5_context->krb5_context, ccache, 
							 princ, 
							 password, NULL, &kdc_time);
		} else {
			/* No password available, try to use a keyblock instead */
			
			krb5_keyblock keyblock;
			const struct samr_Password *mach_pwd;
			mach_pwd = cli_credentials_get_nt_hash(credentials, mem_ctx);
			if (!mach_pwd) {
				talloc_free(mem_ctx);
				DEBUG(1, ("kinit_to_ccache: No password available for kinit\n"));
				return EINVAL;
			}
			ret = krb5_keyblock_init(smb_krb5_context->krb5_context,
						 ENCTYPE_ARCFOUR_HMAC,
						 mach_pwd->hash, sizeof(mach_pwd->hash), 
						 &keyblock);
			
			if (ret == 0) {
				ret = kerberos_kinit_keyblock_cc(smb_krb5_context->krb5_context, ccache, 
								 princ,
								 &keyblock, NULL, &kdc_time);
				krb5_free_keyblock_contents(smb_krb5_context->krb5_context, &keyblock);
			}
		}

		if (ret == KRB5KRB_AP_ERR_SKEW || ret == KRB5_KDCREP_SKEW) {
			/* Perhaps we have been given an invalid skew, so try again without it */
			time_t t = time(NULL);
			krb5_set_real_time(smb_krb5_context->krb5_context, t, 0);
		} else {
			/* not a skew problem */
			break;
		}
	}

	if (ret == KRB5KRB_AP_ERR_SKEW || ret == KRB5_KDCREP_SKEW) {
		DEBUG(1,("kinit for %s failed (%s)\n", 
			 cli_credentials_get_principal(credentials, mem_ctx), 
			 smb_get_krb5_error_message(smb_krb5_context->krb5_context, 
						    ret, mem_ctx)));
		talloc_free(mem_ctx);
		return ret;
	}

	/* cope with ticket being in the future due to clock skew */
	if ((unsigned)kdc_time > time(NULL)) {
		time_t t = time(NULL);
		int time_offset =(unsigned)kdc_time-t;
		DEBUG(4,("Advancing clock by %d seconds to cope with clock skew\n", time_offset));
		krb5_set_real_time(smb_krb5_context->krb5_context, t + time_offset + 1, 0);
	}
	
	if (ret == KRB5KDC_ERR_PREAUTH_FAILED && cli_credentials_wrong_password(credentials)) {
		ret = kinit_to_ccache(parent_ctx,
				      credentials,
				      smb_krb5_context,
				      ccache); 
	}
	if (ret) {
		DEBUG(1,("kinit for %s failed (%s)\n", 
			 cli_credentials_get_principal(credentials, mem_ctx), 
			 smb_get_krb5_error_message(smb_krb5_context->krb5_context, 
						    ret, mem_ctx)));
		talloc_free(mem_ctx);
		return ret;
	} 
	talloc_free(mem_ctx);
	return 0;
}
Exemple #6
0
static NTSTATUS gensec_krb5_update(struct gensec_security *gensec_security, 
				   TALLOC_CTX *out_mem_ctx, 
				   struct tevent_context *ev,
				   const DATA_BLOB in, DATA_BLOB *out) 
{
	struct gensec_krb5_state *gensec_krb5_state = (struct gensec_krb5_state *)gensec_security->private_data;
	krb5_error_code ret = 0;
	NTSTATUS nt_status;

	switch (gensec_krb5_state->state_position) {
	case GENSEC_KRB5_CLIENT_START:
	{
		DATA_BLOB unwrapped_out;
		
		nt_status = gensec_krb5_common_client_creds(gensec_security, ev, gensec_krb5_state->gssapi);
		if (!NT_STATUS_IS_OK(nt_status)) {
			return nt_status;
		}

		if (gensec_krb5_state->gssapi) {
			unwrapped_out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
			
			/* wrap that up in a nice GSS-API wrapping */
			*out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REQ);
		} else {
			*out = data_blob_talloc(out_mem_ctx, gensec_krb5_state->enc_ticket.data, gensec_krb5_state->enc_ticket.length);
		}
		if (gensec_krb5_state->ap_req_options & AP_OPTS_MUTUAL_REQUIRED) {
			gensec_krb5_state->state_position = GENSEC_KRB5_CLIENT_MUTUAL_AUTH;
			nt_status = NT_STATUS_MORE_PROCESSING_REQUIRED;
		} else {
			gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
			nt_status = NT_STATUS_OK;
		}
		return nt_status;
	}
		
	case GENSEC_KRB5_CLIENT_MUTUAL_AUTH:
	{
		DATA_BLOB unwrapped_in;
		krb5_data inbuf;
		krb5_ap_rep_enc_part *repl = NULL;
		uint8_t tok_id[2];

		if (gensec_krb5_state->gssapi) {
			if (!gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
				DEBUG(1,("gensec_gssapi_parse_krb5_wrap(mutual authentication) failed to parse\n"));
				dump_data_pw("Mutual authentication message:\n", in.data, in.length);
				return NT_STATUS_INVALID_PARAMETER;
			}
		} else {
			unwrapped_in = in;
		}
		/* TODO: check the tok_id */

		inbuf.data = unwrapped_in.data;
		inbuf.length = unwrapped_in.length;
		ret = krb5_rd_rep(gensec_krb5_state->smb_krb5_context->krb5_context, 
				  gensec_krb5_state->auth_context,
				  &inbuf, &repl);
		if (ret) {
			DEBUG(1,("krb5_rd_rep (mutual authentication) failed (%s)\n",
				 smb_get_krb5_error_message(gensec_krb5_state->smb_krb5_context->krb5_context, ret, out_mem_ctx)));
			dump_data_pw("Mutual authentication message:\n", (uint8_t *)inbuf.data, inbuf.length);
			nt_status = NT_STATUS_ACCESS_DENIED;
		} else {
			*out = data_blob(NULL, 0);
			nt_status = NT_STATUS_OK;
			gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
		}
		if (repl) {
			krb5_free_ap_rep_enc_part(gensec_krb5_state->smb_krb5_context->krb5_context, repl);
		}
		return nt_status;
	}

	case GENSEC_KRB5_SERVER_START:
	{
		DATA_BLOB unwrapped_in;
		DATA_BLOB unwrapped_out = data_blob(NULL, 0);
		krb5_data inbuf, outbuf;
		uint8_t tok_id[2];
		struct keytab_container *keytab;
		krb5_principal server_in_keytab;
		const char *error_string;
		enum credentials_obtained obtained;

		if (!in.data) {
			return NT_STATUS_INVALID_PARAMETER;
		}	

		/* Grab the keytab, however generated */
		ret = cli_credentials_get_keytab(gensec_get_credentials(gensec_security), 
						 gensec_security->settings->lp_ctx, &keytab);
		if (ret) {
			return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
		}
		
		/* This ensures we lookup the correct entry in that keytab */
		ret = principal_from_credentials(out_mem_ctx, gensec_get_credentials(gensec_security), 
						 gensec_krb5_state->smb_krb5_context, 
						 &server_in_keytab, &obtained, &error_string);

		if (ret) {
			DEBUG(2,("Failed to make credentials from principal: %s\n", error_string));
			return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
		}

		/* Parse the GSSAPI wrapping, if it's there... (win2k3 allows it to be omited) */
		if (gensec_krb5_state->gssapi
		    && gensec_gssapi_parse_krb5_wrap(out_mem_ctx, &in, &unwrapped_in, tok_id)) {
			inbuf.data = unwrapped_in.data;
			inbuf.length = unwrapped_in.length;
		} else {
			inbuf.data = in.data;
			inbuf.length = in.length;
		}

		ret = smb_rd_req_return_stuff(gensec_krb5_state->smb_krb5_context->krb5_context,
					      &gensec_krb5_state->auth_context, 
					      &inbuf, keytab->keytab, server_in_keytab,  
					      &outbuf, 
					      &gensec_krb5_state->ticket, 
					      &gensec_krb5_state->keyblock);

		if (ret) {
			return NT_STATUS_LOGON_FAILURE;
		}
		unwrapped_out.data = (uint8_t *)outbuf.data;
		unwrapped_out.length = outbuf.length;
		gensec_krb5_state->state_position = GENSEC_KRB5_DONE;
		/* wrap that up in a nice GSS-API wrapping */
		if (gensec_krb5_state->gssapi) {
			*out = gensec_gssapi_gen_krb5_wrap(out_mem_ctx, &unwrapped_out, TOK_ID_KRB_AP_REP);
		} else {
			*out = data_blob_talloc(out_mem_ctx, outbuf.data, outbuf.length);
		}
		krb5_data_free(&outbuf);
		return NT_STATUS_OK;
	}

	case GENSEC_KRB5_DONE:
	default:
		/* Asking too many times... */
		return NT_STATUS_INVALID_PARAMETER;
	}
}
static krb5_error_code remove_old_entries(TALLOC_CTX *parent_ctx,
					  struct cli_credentials *machine_account,
					  struct smb_krb5_context *smb_krb5_context,
					  krb5_keytab keytab, BOOL *found_previous)
{
	krb5_error_code ret, ret2;
	krb5_kt_cursor cursor;
	krb5_principal princ;
	int kvno;
	TALLOC_CTX *mem_ctx = talloc_new(parent_ctx);
	const char *princ_string;
	if (!mem_ctx) {
		return ENOMEM;
	}

	*found_previous = False;
	princ_string = cli_credentials_get_principal(machine_account, mem_ctx);

	/* Get the principal we will store the new keytab entries under */
	ret = principal_from_credentials(mem_ctx, machine_account, smb_krb5_context, &princ);
	if (ret) {
		DEBUG(1,("update_keytab: makeing krb5 principal failed (%s)\n",
			 smb_get_krb5_error_message(smb_krb5_context->krb5_context, 
						    ret, mem_ctx)));
		talloc_free(mem_ctx);
		return ret;
	}

	kvno = cli_credentials_get_kvno(machine_account);

	/* for each entry in the keytab */
	ret = krb5_kt_start_seq_get(smb_krb5_context->krb5_context, keytab, &cursor);
	switch (ret) {
	case 0:
		break;
	case HEIM_ERR_OPNOTSUPP:
	case ENOENT:
	case KRB5_KT_END:
		/* no point enumerating if there isn't anything here */
		talloc_free(mem_ctx);
		return 0;
	default:
		DEBUG(1,("failed to open keytab for read of old entries: %s\n",
			 smb_get_krb5_error_message(smb_krb5_context->krb5_context, 
						    ret, mem_ctx)));
		talloc_free(mem_ctx);
		return ret;
	}

	while (!ret) {
		krb5_keytab_entry entry;
		ret = krb5_kt_next_entry(smb_krb5_context->krb5_context, keytab, &entry, &cursor);
		if (ret) {
			break;
		}
		/* if it matches our principal */
		if (!krb5_kt_compare(smb_krb5_context->krb5_context, &entry, princ, 0, 0)) {
			/* Free the entry, it wasn't the one we were looking for anyway */
			krb5_kt_free_entry(smb_krb5_context->krb5_context, &entry);
			continue;
		}

		/* delete it, if it is not kvno -1 */
		if (entry.vno != (kvno - 1 )) {
			/* Release the enumeration.  We are going to
			 * have to start this from the top again,
			 * because deletes during enumeration may not
			 * always be consistant.
			 *
			 * Also, the enumeration locks a FILE: keytab
			 */
		
			krb5_kt_end_seq_get(smb_krb5_context->krb5_context, keytab, &cursor);

			ret = krb5_kt_remove_entry(smb_krb5_context->krb5_context, keytab, &entry);
			krb5_kt_free_entry(smb_krb5_context->krb5_context, &entry);

			/* Deleted: Restart from the top */
			ret2 = krb5_kt_start_seq_get(smb_krb5_context->krb5_context, keytab, &cursor);
			if (ret2) {
				krb5_kt_free_entry(smb_krb5_context->krb5_context, &entry);
				DEBUG(1,("failed to restart enumeration of keytab: %s\n",
					 smb_get_krb5_error_message(smb_krb5_context->krb5_context, 
								    ret, mem_ctx)));
				
				talloc_free(mem_ctx);
				return ret2;
			}

			if (ret) {
				break;
			}
			
		} else {
			*found_previous = True;
		}
		
		/* Free the entry, we don't need it any more */
		krb5_kt_free_entry(smb_krb5_context->krb5_context, &entry);
		
		
	}
	krb5_kt_end_seq_get(smb_krb5_context->krb5_context, keytab, &cursor);

	switch (ret) {
	case 0:
		break;
	case ENOENT:
	case KRB5_KT_END:
		ret = 0;
		break;
	default:
		DEBUG(1,("failed in deleting old entries for principal: %s: %s\n",
			 princ_string, 
			 smb_get_krb5_error_message(smb_krb5_context->krb5_context, 
						    ret, mem_ctx)));
	}
	talloc_free(mem_ctx);
	return ret;
}
static int create_keytab(TALLOC_CTX *parent_ctx,
			 struct cli_credentials *machine_account,
			 struct smb_krb5_context *smb_krb5_context,
			 const char **enctype_strings,
			 krb5_keytab keytab,
			 BOOL add_old) 
{
	krb5_error_code ret;
	const char *password_s;
	const char *old_secret;
	int kvno;
	krb5_principal salt_princ;
	krb5_principal princ;
	const char *princ_string;

	TALLOC_CTX *mem_ctx = talloc_new(parent_ctx);
	if (!mem_ctx) {
		return ENOMEM;
	}

	princ_string = cli_credentials_get_principal(machine_account, mem_ctx);
	/* Get the principal we will store the new keytab entries under */
	ret = principal_from_credentials(mem_ctx, machine_account, smb_krb5_context, &princ);
	if (ret) {
		DEBUG(1,("create_keytab: makeing krb5 principal failed (%s)\n",
			 smb_get_krb5_error_message(smb_krb5_context->krb5_context, 
						    ret, mem_ctx)));
		talloc_free(mem_ctx);
		return ret;
	}

	/* The salt used to generate these entries may be different however, fetch that */
	ret = salt_principal_from_credentials(mem_ctx, machine_account, 
					      smb_krb5_context, 
					      &salt_princ);
	if (ret) {
		DEBUG(1,("create_keytab: makeing salt principal failed (%s)\n",
			 smb_get_krb5_error_message(smb_krb5_context->krb5_context, 
						    ret, mem_ctx)));
		talloc_free(mem_ctx);
		return ret;
	}

	/* Finally, do the dance to get the password to put in the entry */
	password_s = cli_credentials_get_password(machine_account);
	if (!password_s) {
		krb5_keytab_entry entry;
		const struct samr_Password *mach_pwd;

		if (!str_list_check(enctype_strings, "arcfour-hmac-md5")) {
			DEBUG(1, ("Asked to create keytab, but with only an NT hash supplied, "
				  "but not listing arcfour-hmac-md5 as an enc type to include in the keytab!\n"));
			talloc_free(mem_ctx);
			return EINVAL;
		}

		/* If we don't have the plaintext password, try for
		 * the MD4 password hash */
		mach_pwd = cli_credentials_get_nt_hash(machine_account, mem_ctx);
		if (!mach_pwd) {
			/* OK, nothing to do here */
			talloc_free(mem_ctx);
			return 0;
		}
		ret = krb5_keyblock_init(smb_krb5_context->krb5_context,
					 ETYPE_ARCFOUR_HMAC_MD5,
					 mach_pwd->hash, sizeof(mach_pwd->hash), 
					 &entry.keyblock);
		if (ret) {
			DEBUG(1, ("create_keytab: krb5_keyblock_init failed: %s\n",
				  smb_get_krb5_error_message(smb_krb5_context->krb5_context, 
							     ret, mem_ctx)));
			talloc_free(mem_ctx);
			return ret;
		}

		entry.principal = princ;
		entry.vno       = cli_credentials_get_kvno(machine_account);
		ret = krb5_kt_add_entry(smb_krb5_context->krb5_context, keytab, &entry);
		if (ret) {
			DEBUG(1, ("Failed to add ARCFOUR_HMAC (only) entry for %s to keytab: %s",
				  cli_credentials_get_principal(machine_account, mem_ctx), 
				  smb_get_krb5_error_message(smb_krb5_context->krb5_context, 
							     ret, mem_ctx)));
			talloc_free(mem_ctx);
			krb5_free_keyblock_contents(smb_krb5_context->krb5_context, &entry.keyblock);
			return ret;
		}
		
		DEBUG(5, ("Added %s(kvno %d) to keytab (arcfour-hmac-md5)\n", 
			  cli_credentials_get_principal(machine_account, mem_ctx),
			  cli_credentials_get_kvno(machine_account)));

		krb5_free_keyblock_contents(smb_krb5_context->krb5_context, &entry.keyblock);

		/* Can't go any further, we only have this one key */
		talloc_free(mem_ctx);
		return 0;
	}
	
	kvno = cli_credentials_get_kvno(machine_account);
	/* good, we actually have the real plaintext */
	ret = keytab_add_keys(mem_ctx, princ_string, princ, salt_princ, 
			      kvno, password_s, smb_krb5_context, 
			      enctype_strings, keytab);
	if (!ret) {
		talloc_free(mem_ctx);
		return ret;
	}

	if (!add_old || kvno == 0) {
		talloc_free(mem_ctx);
		return 0;
	}

	old_secret = cli_credentials_get_old_password(machine_account);
	if (!old_secret) {
		talloc_free(mem_ctx);
		return 0;
	}
	
	ret = keytab_add_keys(mem_ctx, princ_string, princ, salt_princ, 
			      kvno - 1, old_secret, smb_krb5_context, 
			      enctype_strings, keytab);
	if (!ret) {
		talloc_free(mem_ctx);
		return ret;
	}

	talloc_free(mem_ctx);
	return 0;
}