X-Git-Url: http://git.samba.org/idra/samba.git/?p=idra%2Fsamba.git;a=blobdiff_plain;f=lib%2Fkrb5_wrap%2Fkrb5_samba.c;h=0a4302dd6949061c5068d6f98c6bf5579075d007;hp=4e555b285331086e515ac564fb906c09a338187e;hb=9a4446a8ca66f08ef834a1488fa0e6a17a33228a;hpb=08c733d75fd83fd5e32ced9712d41dd595e0f182;ds=sidebyside

diff --git a/lib/krb5_wrap/krb5_samba.c b/lib/krb5_wrap/krb5_samba.c
index 4e555b28533..0a4302dd694 100644
--- a/lib/krb5_wrap/krb5_samba.c
+++ b/lib/krb5_wrap/krb5_samba.c
@@ -39,6 +39,7 @@
 #define GSSAPI_BNDLENGTH     16                 /* Bind Length (rfc-1964 pg.3) */
 #define GSSAPI_CHECKSUM_SIZE (4+GSSAPI_BNDLENGTH+4) /* Length of bind length,
 							bind field, flags field. */
+#define GSS_C_DELEG_FLAG 1
 
 /* MIT krb5 1.7beta3 (in Ubuntu Karmic) is missing the prototype,
    but still has the symbol */
@@ -1551,6 +1552,522 @@ krb5_error_code smb_krb5_get_creds(const char *server_s,
 	return ret;
 }
 
+/*
+  simulate a kinit, putting the tgt in the given credentials cache.
+  Orignally by remus@snapserver.com
+
+  This version is built to use a keyblock, rather than needing the
+  original password.
+
+  The impersonate_principal is the principal if NULL, or the principal
+  to impersonate
+
+  The target_service defaults to the krbtgt if NULL, but could be
+   kpasswd/realm or the local service (if we are doing s4u2self)
+*/
+krb5_error_code kerberos_kinit_keyblock_cc(krb5_context ctx, krb5_ccache cc,
+					   krb5_principal principal,
+					   krb5_keyblock *keyblock,
+					   const char *target_service,
+					   krb5_get_init_creds_opt *krb_options,
+					   time_t *expire_time,
+					   time_t *kdc_time)
+{
+	krb5_error_code code = 0;
+	krb5_creds my_creds;
+
+#if defined(HAVE_KRB5_GET_INIT_CREDS_KEYBLOCK)
+	code = krb5_get_init_creds_keyblock(ctx, &my_creds, principal,
+					    keyblock, 0, target_service,
+					    krb_options);
+#elif defined(HAVE_KRB5_GET_INIT_CREDS_KEYTAB)
+{
+#define SMB_CREDS_KEYTAB "MEMORY:tmp_smb_creds_XXXXXX"
+	char *tmp_name[sizeof(SMB_CREDS_KEYTAB)];
+	krb5_keytab_entry entry;
+	krb5_keytab keytab;
+
+	memset(entry, 0, sizeof(entry));
+	entry.principal = principal;
+	entry.key = keyblock;
+
+	memcpy(tmp_name, SMB_CREDS_KEYTAB, sizeof(SMB_CREDS_KEYTAB))
+	mktemp(tmp_name);
+	if (tmp_name[0] == 0) {
+		return KRB5_KT_BADNAME;
+	}
+	code = krb5_kt_resolve(ctx, tmp_name, &keytab);
+	if (code) {
+		return code;
+	}
+
+	code = krb5_kt_add_entry(ctx, keytab, &entry);
+	if (code) {
+		(void)krb5_kt_close(ctx, keytab);
+		goto done;
+	}
+
+	code = krb5_get_init_creds_keytab(ctx, &my_creds, principal,
+					  keytab, 0, target_service,
+					  krb_options);
+	(void)krb5_kt_close(ctx, keytab);
+}
+#else
+#error krb5_get_init_creds_keyblock not available!
+#endif
+	if (code) {
+		return code;
+	}
+
+	code = krb5_cc_initialize(ctx, cc, principal);
+	if (code) {
+		goto done;
+	}
+
+	code = krb5_cc_store_cred(ctx, cc, &my_creds);
+	if (code) {
+		goto done;
+	}
+
+	if (expire_time) {
+		*expire_time = (time_t) my_creds.times.endtime;
+	}
+
+	if (kdc_time) {
+		*kdc_time = (time_t) my_creds.times.starttime;
+	}
+
+	code = 0;
+done:
+	krb5_free_cred_contents(ctx, &my_creds);
+	return code;
+}
+
+krb5_error_code kerberos_kinit_password_cc(krb5_context ctx, krb5_ccache cc,
+					   krb5_principal principal,
+					   const char *password,
+					   const char *target_service,
+					   krb5_get_init_creds_opt *krb_options,
+					   time_t *expire_time,
+					   time_t *kdc_time)
+{
+	krb5_error_code code = 0;
+	krb5_creds my_creds;
+
+	code = krb5_get_init_creds_password(ctx, &my_creds, principal,
+					    password, NULL, NULL, 0,
+					    target_service, krb_options);
+	if (code) {
+		return code;
+	}
+
+	code = krb5_cc_initialize(ctx, cc, principal);
+	if (code) {
+		goto done;
+	}
+
+	code = krb5_cc_store_cred(ctx, cc, &my_creds);
+	if (code) {
+		goto done;
+	}
+
+	if (expire_time) {
+		*expire_time = (time_t) my_creds.times.endtime;
+	}
+
+	if (kdc_time) {
+		*kdc_time = (time_t) my_creds.times.starttime;
+	}
+
+	code = 0;
+done:
+	krb5_free_cred_contents(ctx, &my_creds);
+	return code;
+}
+
+#ifdef SAMBA4_USES_HEIMDAL
+/*
+  simulate a kinit, putting the tgt in the given credentials cache.
+  Orignally by remus@snapserver.com
+
+  The impersonate_principal is the principal
+
+  The self_service, should be the local service (for S4U2Self if
+  impersonate_principal is given).
+
+  The target_service defaults to the krbtgt if NULL, but could be
+  kpasswd/realm or a remote service (for S4U2Proxy)
+
+*/
+krb5_error_code kerberos_kinit_s4u2_cc(krb5_context ctx,
+					krb5_ccache store_cc,
+					krb5_principal init_principal,
+					const char *init_password,
+					krb5_principal impersonate_principal,
+					const char *self_service,
+					const char *target_service,
+					krb5_get_init_creds_opt *krb_options,
+					time_t *expire_time,
+					time_t *kdc_time)
+{
+	krb5_error_code code = 0;
+	krb5_get_creds_opt options;
+	krb5_principal store_principal;
+	krb5_creds store_creds;
+	krb5_creds *s4u2self_creds;
+	Ticket s4u2self_ticket;
+	size_t s4u2self_ticketlen;
+	krb5_creds *s4u2proxy_creds;
+	krb5_principal self_princ;
+	bool s4u2proxy;
+	krb5_principal target_princ;
+	krb5_ccache tmp_cc;
+	const char *self_realm;
+	krb5_principal blacklist_principal = NULL;
+	krb5_principal whitelist_principal = NULL;
+
+	code = krb5_get_init_creds_password(ctx, &store_creds,
+					    init_principal,
+					    init_password,
+					    NULL, NULL,
+					    0,
+					    impersonate_principal,
+					    krb_options);
+	if (code != 0) {
+		return code;
+	}
+
+	store_principal = init_principal;
+
+	/*
+	 * We are trying S4U2Self now:
+	 *
+	 * As we do not want to expose our TGT in the
+	 * krb5_ccache, which is also holds the impersonated creds.
+	 *
+	 * Some low level krb5/gssapi function might use the TGT
+	 * identity and let the client act as our machine account.
+	 *
+	 * We need to avoid that and use a temporary krb5_ccache
+	 * in order to pass our TGT to the krb5_get_creds() function.
+	 */
+	code = krb5_cc_new_unique(ctx, NULL, NULL, &tmp_cc);
+	if (code != 0) {
+		krb5_free_cred_contents(ctx, &store_creds);
+		return code;
+	}
+
+	code = krb5_cc_initialize(ctx, tmp_cc, store_creds.client);
+	if (code != 0) {
+		krb5_cc_destroy(ctx, tmp_cc);
+		krb5_free_cred_contents(ctx, &store_creds);
+		return code;
+	}
+
+	code = krb5_cc_store_cred(ctx, tmp_cc, &store_creds);
+	if (code != 0) {
+		krb5_free_cred_contents(ctx, &store_creds);
+		krb5_cc_destroy(ctx, tmp_cc);
+		return code;
+	}
+
+	/*
+	 * we need to remember the client principal of our
+	 * TGT and make sure the KDC does not return this
+	 * in the impersonated tickets. This can happen
+	 * if the KDC does not support S4U2Self and S4U2Proxy.
+	 */
+	blacklist_principal = store_creds.client;
+	store_creds.client = NULL;
+	krb5_free_cred_contents(ctx, &store_creds);
+
+	/*
+	 * Check if we also need S4U2Proxy or if S4U2Self is
+	 * enough in order to get a ticket for the target.
+	 */
+	if (target_service == NULL) {
+		s4u2proxy = false;
+	} else if (strcmp(target_service, self_service) == 0) {
+		s4u2proxy = false;
+	} else {
+		s4u2proxy = true;
+	}
+
+	/*
+	 * For S4U2Self we need our own service principal,
+	 * which belongs to our own realm (available on
+	 * our client principal).
+	 */
+	self_realm = krb5_principal_get_realm(ctx, init_principal);
+
+	code = krb5_parse_name(ctx, self_service, &self_princ);
+	if (code != 0) {
+		krb5_free_principal(ctx, blacklist_principal);
+		krb5_cc_destroy(ctx, tmp_cc);
+		return code;
+	}
+
+	code = krb5_principal_set_realm(ctx, self_princ, self_realm);
+	if (code != 0) {
+		krb5_free_principal(ctx, blacklist_principal);
+		krb5_free_principal(ctx, self_princ);
+		krb5_cc_destroy(ctx, tmp_cc);
+		return code;
+	}
+
+	code = krb5_get_creds_opt_alloc(ctx, &options);
+	if (code != 0) {
+		krb5_free_principal(ctx, blacklist_principal);
+		krb5_free_principal(ctx, self_princ);
+		krb5_cc_destroy(ctx, tmp_cc);
+		return code;
+	}
+
+	if (s4u2proxy) {
+		/*
+		 * If we want S4U2Proxy, we need the forwardable flag
+		 * on the S4U2Self ticket.
+		 */
+		krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_FORWARDABLE);
+	}
+
+	code = krb5_get_creds_opt_set_impersonate(ctx, options,
+						  impersonate_principal);
+	if (code != 0) {
+		krb5_get_creds_opt_free(ctx, options);
+		krb5_free_principal(ctx, blacklist_principal);
+		krb5_free_principal(ctx, self_princ);
+		krb5_cc_destroy(ctx, tmp_cc);
+		return code;
+	}
+
+	code = krb5_get_creds(ctx, options, tmp_cc,
+			      self_princ, &s4u2self_creds);
+	krb5_get_creds_opt_free(ctx, options);
+	krb5_free_principal(ctx, self_princ);
+	if (code != 0) {
+		krb5_free_principal(ctx, blacklist_principal);
+		krb5_cc_destroy(ctx, tmp_cc);
+		return code;
+	}
+
+	if (!s4u2proxy) {
+		krb5_cc_destroy(ctx, tmp_cc);
+
+		/*
+		 * Now make sure we store the impersonated principal
+		 * and creds instead of the TGT related stuff
+		 * in the krb5_ccache of the caller.
+		 */
+		code = krb5_copy_creds_contents(ctx, s4u2self_creds,
+						&store_creds);
+		krb5_free_creds(ctx, s4u2self_creds);
+		if (code != 0) {
+			return code;
+		}
+
+		/*
+		 * It's important to store the principal the KDC
+		 * returned, as otherwise the caller would not find
+		 * the S4U2Self ticket in the krb5_ccache lookup.
+		 */
+		store_principal = store_creds.client;
+		goto store;
+	}
+
+	/*
+	 * We are trying S4U2Proxy:
+	 *
+	 * We need the ticket from the S4U2Self step
+	 * and our TGT in order to get the delegated ticket.
+	 */
+	code = decode_Ticket((const uint8_t *)s4u2self_creds->ticket.data,
+			     s4u2self_creds->ticket.length,
+			     &s4u2self_ticket,
+			     &s4u2self_ticketlen);
+	if (code != 0) {
+		krb5_free_creds(ctx, s4u2self_creds);
+		krb5_free_principal(ctx, blacklist_principal);
+		krb5_cc_destroy(ctx, tmp_cc);
+		return code;
+	}
+
+	/*
+	 * we need to remember the client principal of the
+	 * S4U2Self stage and as it needs to match the one we
+	 * will get for the S4U2Proxy stage. We need this
+	 * in order to detect KDCs which does not support S4U2Proxy.
+	 */
+	whitelist_principal = s4u2self_creds->client;
+	s4u2self_creds->client = NULL;
+	krb5_free_creds(ctx, s4u2self_creds);
+
+	/*
+	 * For S4U2Proxy we also got a target service principal,
+	 * which also belongs to our own realm (available on
+	 * our client principal).
+	 */
+	code = krb5_parse_name(ctx, target_service, &target_princ);
+	if (code != 0) {
+		free_Ticket(&s4u2self_ticket);
+		krb5_free_principal(ctx, whitelist_principal);
+		krb5_free_principal(ctx, blacklist_principal);
+		krb5_cc_destroy(ctx, tmp_cc);
+		return code;
+	}
+
+	code = krb5_principal_set_realm(ctx, target_princ, self_realm);
+	if (code != 0) {
+		free_Ticket(&s4u2self_ticket);
+		krb5_free_principal(ctx, target_princ);
+		krb5_free_principal(ctx, whitelist_principal);
+		krb5_free_principal(ctx, blacklist_principal);
+		krb5_cc_destroy(ctx, tmp_cc);
+		return code;
+	}
+
+	code = krb5_get_creds_opt_alloc(ctx, &options);
+	if (code != 0) {
+		free_Ticket(&s4u2self_ticket);
+		krb5_free_principal(ctx, target_princ);
+		krb5_free_principal(ctx, whitelist_principal);
+		krb5_free_principal(ctx, blacklist_principal);
+		krb5_cc_destroy(ctx, tmp_cc);
+		return code;
+	}
+
+	krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_FORWARDABLE);
+	krb5_get_creds_opt_set_options(ctx, options, KRB5_GC_CONSTRAINED_DELEGATION);
+
+	code = krb5_get_creds_opt_set_ticket(ctx, options, &s4u2self_ticket);
+	free_Ticket(&s4u2self_ticket);
+	if (code != 0) {
+		krb5_get_creds_opt_free(ctx, options);
+		krb5_free_principal(ctx, target_princ);
+		krb5_free_principal(ctx, whitelist_principal);
+		krb5_free_principal(ctx, blacklist_principal);
+		krb5_cc_destroy(ctx, tmp_cc);
+		return code;
+	}
+
+	code = krb5_get_creds(ctx, options, tmp_cc,
+			      target_princ, &s4u2proxy_creds);
+	krb5_get_creds_opt_free(ctx, options);
+	krb5_free_principal(ctx, target_princ);
+	krb5_cc_destroy(ctx, tmp_cc);
+	if (code != 0) {
+		krb5_free_principal(ctx, whitelist_principal);
+		krb5_free_principal(ctx, blacklist_principal);
+		return code;
+	}
+
+	/*
+	 * Now make sure we store the impersonated principal
+	 * and creds instead of the TGT related stuff
+	 * in the krb5_ccache of the caller.
+	 */
+	code = krb5_copy_creds_contents(ctx, s4u2proxy_creds,
+					&store_creds);
+	krb5_free_creds(ctx, s4u2proxy_creds);
+	if (code != 0) {
+		krb5_free_principal(ctx, whitelist_principal);
+		krb5_free_principal(ctx, blacklist_principal);
+		return code;
+	}
+
+	/*
+	 * It's important to store the principal the KDC
+	 * returned, as otherwise the caller would not find
+	 * the S4U2Self ticket in the krb5_ccache lookup.
+	 */
+	store_principal = store_creds.client;
+
+ store:
+	if (blacklist_principal &&
+	    krb5_principal_compare(ctx, store_creds.client, blacklist_principal)) {
+		char *sp = NULL;
+		char *ip = NULL;
+
+		code = krb5_unparse_name(ctx, blacklist_principal, &sp);
+		if (code != 0) {
+			sp = NULL;
+		}
+		code = krb5_unparse_name(ctx, impersonate_principal, &ip);
+		if (code != 0) {
+			ip = NULL;
+		}
+		DEBUG(1, ("kerberos_kinit_password_cc: "
+			  "KDC returned self principal[%s] while impersonating [%s]\n",
+			  sp?sp:"<no memory>",
+			  ip?ip:"<no memory>"));
+
+		SAFE_FREE(sp);
+		SAFE_FREE(ip);
+
+		krb5_free_principal(ctx, whitelist_principal);
+		krb5_free_principal(ctx, blacklist_principal);
+		krb5_free_cred_contents(ctx, &store_creds);
+		return KRB5_FWD_BAD_PRINCIPAL;
+	}
+	if (blacklist_principal) {
+		krb5_free_principal(ctx, blacklist_principal);
+	}
+
+	if (whitelist_principal &&
+	    !krb5_principal_compare(ctx, store_creds.client, whitelist_principal)) {
+		char *sp = NULL;
+		char *ep = NULL;
+
+		code = krb5_unparse_name(ctx, store_creds.client, &sp);
+		if (code != 0) {
+			sp = NULL;
+		}
+		code = krb5_unparse_name(ctx, whitelist_principal, &ep);
+		if (code != 0) {
+			ep = NULL;
+		}
+		DEBUG(1, ("kerberos_kinit_password_cc: "
+			  "KDC returned wrong principal[%s] we expected [%s]\n",
+			  sp?sp:"<no memory>",
+			  ep?ep:"<no memory>"));
+
+		SAFE_FREE(sp);
+		SAFE_FREE(ep);
+
+		krb5_free_principal(ctx, whitelist_principal);
+		krb5_free_cred_contents(ctx, &store_creds);
+		return KRB5_FWD_BAD_PRINCIPAL;
+	}
+	if (whitelist_principal) {
+		krb5_free_principal(ctx, whitelist_principal);
+	}
+
+	code = krb5_cc_initialize(ctx, store_cc, store_principal);
+	if (code != 0) {
+		krb5_free_cred_contents(ctx, &store_creds);
+		return code;
+	}
+
+	code = krb5_cc_store_cred(ctx, store_cc, &store_creds);
+	if (code != 0) {
+		krb5_free_cred_contents(ctx, &store_creds);
+		return code;
+	}
+
+	if (expire_time) {
+		*expire_time = (time_t) store_creds.times.endtime;
+	}
+
+	if (kdc_time) {
+		*kdc_time = (time_t) store_creds.times.starttime;
+	}
+
+	krb5_free_cred_contents(ctx, &store_creds);
+
+	return 0;
+}
+#endif
+
 /*
  * smb_krb5_principal_get_realm
  *