[SCM] Samba Shared Repository - branch master updated

Alexander Bokovoy ab at samba.org
Wed Sep 12 13:19:02 MDT 2012


The branch, master has been updated
       via  893b213 Avoid overriding default ccache for ads operations.
      from  a11e45f selftest: let provision_plugin_s4_dc use SMB3

http://gitweb.samba.org/?p=samba.git;a=shortlog;h=master


- Log -----------------------------------------------------------------
commit 893b21387665a7b644355d60f6fbccaf48ffaedb
Author: Simo Sorce <idra at samba.org>
Date:   Fri Sep 7 14:14:08 2012 -0400

    Avoid overriding default ccache for ads operations.
    
    Avoid overriding default ccache for ads operations.
    
    Nowadays various samba components may need to use GSSAPI and a default cred
    cache to perform their tasks.
    This code was completely overriding the whole process default ccache name, thus
    altering the current credentials and sometimes hijacking them (or getting
    preemptively hijaked).
    
    By using gss_krb5_import_cred we can instead use a private ccache (necessary
    sometimes to use a different set of credentials fromt he default
    cifs/fqdn at realm one, for example when contacting foreign DCs using trust
    credentials) that does not affect the rest of the process.
    
    For the kerberos versions which don't have gss_krb5_import_cred
    we fallback to temp override of KRB5CCNAME and gss_acquire_cred.
    
    Signed-off-by: Alexander Bokovoy <ab at samba.org>
    Signed-off-by: Günther Deschner <gd at samba.org>
    
    Autobuild-User(master): Alexander Bokovoy <ab at samba.org>
    Autobuild-Date(master): Wed Sep 12 21:18:09 CEST 2012 on sn-devel-104

-----------------------------------------------------------------------

Summary of changes:
 source3/include/ads.h           |    1 +
 source3/include/proto.h         |    2 +-
 source3/libads/ads_struct.c     |    1 +
 source3/libads/kerberos_util.c  |    8 ++-
 source3/libads/sasl.c           |   92 +++++++++++++++++++++++++++++++++++++--
 source3/libsmb/cliconnect.c     |    2 +-
 source3/libsmb/clispnego.c      |    4 +-
 source3/winbindd/winbindd_ads.c |    6 +-
 8 files changed, 102 insertions(+), 14 deletions(-)


Changeset truncated at 500 lines:

diff --git a/source3/include/ads.h b/source3/include/ads.h
index 91a0f81..3de1d8b 100644
--- a/source3/include/ads.h
+++ b/source3/include/ads.h
@@ -45,6 +45,7 @@ typedef struct ads_struct {
 		char *kdc_server;
 		unsigned flags;
 		int time_offset;
+		char *ccache_name;
 		time_t tgt_expire;
 		time_t tgs_expire;
 		time_t renewable;
diff --git a/source3/include/proto.h b/source3/include/proto.h
index 6dbdf4e..b3fa55a 100644
--- a/source3/include/proto.h
+++ b/source3/include/proto.h
@@ -768,7 +768,7 @@ int spnego_gen_krb5_negTokenInit(TALLOC_CTX *ctx,
 			    const char *principal, int time_offset,
 			    DATA_BLOB *targ,
 			    DATA_BLOB *session_key_krb5, uint32 extra_ap_opts,
-			    time_t *expire_time);
+			    const char *ccname, time_t *expire_time);
 bool spnego_parse_challenge(TALLOC_CTX *ctx, const DATA_BLOB blob,
 			    DATA_BLOB *chal1, DATA_BLOB *chal2);
 DATA_BLOB spnego_gen_auth(TALLOC_CTX *ctx, DATA_BLOB blob);
diff --git a/source3/libads/ads_struct.c b/source3/libads/ads_struct.c
index 45d00a3..fd7e417 100644
--- a/source3/libads/ads_struct.c
+++ b/source3/libads/ads_struct.c
@@ -201,6 +201,7 @@ void ads_destroy(ADS_STRUCT **ads)
 		SAFE_FREE((*ads)->auth.password);
 		SAFE_FREE((*ads)->auth.user_name);
 		SAFE_FREE((*ads)->auth.kdc_server);
+		SAFE_FREE((*ads)->auth.ccache_name);
 
 		SAFE_FREE((*ads)->config.realm);
 		SAFE_FREE((*ads)->config.bind_path);
diff --git a/source3/libads/kerberos_util.c b/source3/libads/kerberos_util.c
index 7d49c02..645b058 100644
--- a/source3/libads/kerberos_util.c
+++ b/source3/libads/kerberos_util.c
@@ -63,9 +63,11 @@ int ads_kinit_password(ADS_STRUCT *ads)
 		return KRB5_LIBOS_CANTREADPWD;
 	}
 
-	ret = kerberos_kinit_password_ext(s, ads->auth.password, ads->auth.time_offset,
-			&ads->auth.tgt_expire, NULL, NULL, False, False, ads->auth.renewable,
-			NULL);
+	ret = kerberos_kinit_password_ext(s, ads->auth.password,
+					  ads->auth.time_offset,
+					  &ads->auth.tgt_expire, NULL,
+					  ads->auth.ccache_name, false, false,
+					  ads->auth.renewable, NULL);
 
 	if (ret) {
 		DEBUG(0,("kerberos_kinit_password %s failed: %s\n",
diff --git a/source3/libads/sasl.c b/source3/libads/sasl.c
index 438db05..33f4e24 100644
--- a/source3/libads/sasl.c
+++ b/source3/libads/sasl.c
@@ -271,6 +271,74 @@ static ADS_STATUS ads_sasl_spnego_ntlmssp_bind(ADS_STRUCT *ads)
 }
 
 #ifdef HAVE_KRB5
+static ADS_STATUS ads_init_gssapi_cred(ADS_STRUCT *ads, gss_cred_id_t *cred)
+{
+	ADS_STATUS status;
+	krb5_context kctx;
+	krb5_error_code kerr;
+	krb5_ccache kccache = NULL;
+	uint32_t maj, min;
+
+	*cred = GSS_C_NO_CREDENTIAL;
+
+	if (!ads->auth.ccache_name) {
+		return ADS_SUCCESS;
+	}
+
+	kerr = krb5_init_context(&kctx);
+	if (kerr) {
+		return ADS_ERROR_KRB5(kerr);
+	}
+
+#ifdef HAVE_GSS_KRB5_IMPORT_CRED
+	kerr = krb5_cc_resolve(kctx, ads->auth.ccache_name, &kccache);
+	if (kerr) {
+		status = ADS_ERROR_KRB5(kerr);
+		goto done;
+	}
+
+	maj = gss_krb5_import_cred(&min, kccache, NULL, NULL, cred);
+	if (maj != GSS_S_COMPLETE) {
+		status = ADS_ERROR_GSS(maj, min);
+		goto done;
+	}
+#else
+	/* We need to fallback to overriding the default creds.
+	 * This operation is not thread safe as it changes the process
+	 * environment variable, but we do not have any better option
+	 * with older kerberos libraries */
+	{
+		const char *oldccname = NULL;
+
+		oldccname = getenv("KRB5CCNAME");
+		setenv("KRB5CCNAME", ads->auth.ccache_name, 1);
+
+		maj = gss_acquire_cred(&min, GSS_C_NO_NAME, GSS_C_INDEFINITE,
+				       NULL, GSS_C_INITIATE, cred, NULL, NULL);
+
+		if (oldccname) {
+			setenv("KRB5CCNAME", oldccname, 1);
+		} else {
+			unsetenv("KRB5CCNAME");
+		}
+
+		if (maj != GSS_S_COMPLETE) {
+			status = ADS_ERROR_GSS(maj, min);
+			goto done;
+		}
+	}
+#endif
+
+	status = ADS_SUCCESS;
+
+done:
+	if (!ADS_ERR_OK(status) && kccache != NULL) {
+		krb5_cc_close(kctx, kccache);
+	}
+	krb5_free_context(kctx);
+	return status;
+}
+
 static ADS_STATUS ads_sasl_gssapi_wrap(ADS_STRUCT *ads, uint8 *buf, uint32 len)
 {
 	gss_ctx_id_t context_handle = (gss_ctx_id_t)ads->ldap.wrap_private_data;
@@ -377,6 +445,7 @@ static ADS_STATUS ads_sasl_spnego_gsskrb5_bind(ADS_STRUCT *ads, const gss_name_t
 	bool ok;
 	uint32 minor_status;
 	int gss_rc, rc;
+	gss_cred_id_t gss_cred = GSS_C_NO_CREDENTIAL;
 	gss_OID_desc krb5_mech_type =
 	{9, discard_const_p(char, "\x2a\x86\x48\x86\xf7\x12\x01\x02\x02") };
 	gss_OID mech_type = &krb5_mech_type;
@@ -390,6 +459,11 @@ static ADS_STATUS ads_sasl_spnego_gsskrb5_bind(ADS_STRUCT *ads, const gss_name_t
 	DATA_BLOB wrapped;
 	struct berval cred, *scred = NULL;
 
+	status = ads_init_gssapi_cred(ads, &gss_cred);
+	if (!ADS_ERR_OK(status)) {
+		goto failed;
+	}
+
 	input_token.value = NULL;
 	input_token.length = 0;
 
@@ -407,7 +481,7 @@ static ADS_STATUS ads_sasl_spnego_gsskrb5_bind(ADS_STRUCT *ads, const gss_name_t
 
 	/* Note: here we explicit ask for the krb5 mech_type */
 	gss_rc = gss_init_sec_context(&minor_status,
-				      GSS_C_NO_CREDENTIAL,
+				      gss_cred,
 				      &context_handle,
 				      serv_name,
 				      mech_type,
@@ -544,7 +618,7 @@ static ADS_STATUS ads_sasl_spnego_gsskrb5_bind(ADS_STRUCT *ads, const gss_name_t
 	 * to gssapi
 	 */
 	gss_rc = gss_init_sec_context(&minor_status,
-				      GSS_C_NO_CREDENTIAL,
+				      gss_cred,
 				      &context_handle,
 				      serv_name,
 				      mech_type,
@@ -606,6 +680,8 @@ static ADS_STATUS ads_sasl_spnego_gsskrb5_bind(ADS_STRUCT *ads, const gss_name_t
 	status = ADS_SUCCESS;
 
 failed:
+	if (gss_cred != GSS_C_NO_CREDENTIAL)
+		gss_release_cred(&minor_status, &gss_cred);
 	if (context_handle != GSS_C_NO_CONTEXT)
 		gss_delete_sec_context(&minor_status, &context_handle, GSS_C_NO_BUFFER);
 	return status;
@@ -791,6 +867,7 @@ static ADS_STATUS ads_sasl_spnego_rawkrb5_bind(ADS_STRUCT *ads, const char *prin
 
 	rc = spnego_gen_krb5_negTokenInit(talloc_tos(), principal,
 				     ads->auth.time_offset, &blob, &session_key, 0,
+				     ads->auth.ccache_name,
 				     &ads->auth.tgs_expire);
 
 	if (rc) {
@@ -952,6 +1029,7 @@ failed:
 static ADS_STATUS ads_sasl_gssapi_do_bind(ADS_STRUCT *ads, const gss_name_t serv_name)
 {
 	uint32 minor_status;
+	gss_cred_id_t gss_cred = GSS_C_NO_CREDENTIAL;
 	gss_ctx_id_t context_handle = GSS_C_NO_CONTEXT;
 	gss_OID mech_type = GSS_C_NULL_OID;
 	gss_buffer_desc output_token, input_token;
@@ -969,6 +1047,11 @@ static ADS_STATUS ads_sasl_gssapi_do_bind(ADS_STRUCT *ads, const gss_name_t serv
 	input_token.value = NULL;
 	input_token.length = 0;
 
+	status = ads_init_gssapi_cred(ads, &gss_cred);
+	if (!ADS_ERR_OK(status)) {
+		goto failed;
+	}
+
 	/*
 	 * Note: here we always ask the gssapi for sign and seal
 	 *       as this is negotiated later after the mutal
@@ -978,7 +1061,7 @@ static ADS_STATUS ads_sasl_gssapi_do_bind(ADS_STRUCT *ads, const gss_name_t serv
 
 	for (i=0; i < MAX_GSS_PASSES; i++) {
 		gss_rc = gss_init_sec_context(&minor_status,
-					  GSS_C_NO_CREDENTIAL,
+					  gss_cred,
 					  &context_handle,
 					  serv_name,
 					  mech_type,
@@ -1137,7 +1220,8 @@ static ADS_STATUS ads_sasl_gssapi_do_bind(ADS_STRUCT *ads, const gss_name_t serv
 	}
 
 failed:
-
+	if (gss_cred != GSS_C_NO_CREDENTIAL)
+		gss_release_cred(&minor_status, &gss_cred);
 	if (context_handle != GSS_C_NO_CONTEXT)
 		gss_delete_sec_context(&minor_status, &context_handle, GSS_C_NO_BUFFER);
 
diff --git a/source3/libsmb/cliconnect.c b/source3/libsmb/cliconnect.c
index b74faa6..9ce013e 100644
--- a/source3/libsmb/cliconnect.c
+++ b/source3/libsmb/cliconnect.c
@@ -1461,7 +1461,7 @@ static struct tevent_req *cli_session_setup_kerberos_send(
 	 * we have to acquire a ticket. To be fixed later :-)
 	 */
 	rc = spnego_gen_krb5_negTokenInit(state, principal, 0, &state->negTokenTarg,
-				     &state->session_key_krb5, 0, NULL);
+				     &state->session_key_krb5, 0, NULL, NULL);
 	if (rc) {
 		DEBUG(1, ("cli_session_setup_kerberos: "
 			  "spnego_gen_krb5_negTokenInit failed: %s\n",
diff --git a/source3/libsmb/clispnego.c b/source3/libsmb/clispnego.c
index 81f9dfb..a17efbf 100644
--- a/source3/libsmb/clispnego.c
+++ b/source3/libsmb/clispnego.c
@@ -255,7 +255,7 @@ int spnego_gen_krb5_negTokenInit(TALLOC_CTX *ctx,
 			    const char *principal, int time_offset,
 			    DATA_BLOB *targ,
 			    DATA_BLOB *session_key_krb5, uint32 extra_ap_opts,
-			    time_t *expire_time)
+			    const char *ccname, time_t *expire_time)
 {
 	int retval;
 	DATA_BLOB tkt, tkt_wrapped;
@@ -264,7 +264,7 @@ int spnego_gen_krb5_negTokenInit(TALLOC_CTX *ctx,
 	/* get a kerberos ticket for the service and extract the session key */
 	retval = cli_krb5_get_ticket(ctx, principal, time_offset,
 					  &tkt, session_key_krb5,
-					  extra_ap_opts, NULL,
+					  extra_ap_opts, ccname,
 					  expire_time, NULL);
 	if (retval) {
 		return retval;
diff --git a/source3/winbindd/winbindd_ads.c b/source3/winbindd/winbindd_ads.c
index 4efd829..628fd1c 100644
--- a/source3/winbindd/winbindd_ads.c
+++ b/source3/winbindd/winbindd_ads.c
@@ -78,15 +78,15 @@ static ADS_STRUCT *ads_cached_connection(struct winbindd_domain *domain)
 		}
 	}
 
-	/* we don't want this to affect the users ccache */
-	setenv("KRB5CCNAME", "MEMORY:winbind_ccache", 1);
-
 	ads = ads_init(domain->alt_name, domain->name, NULL);
 	if (!ads) {
 		DEBUG(1,("ads_init for domain %s failed\n", domain->name));
 		return NULL;
 	}
 
+	/* we don't want ads operations to affect the default ccache */
+	ads->auth.ccache_name = SMB_STRDUP("MEMORY:winbind_ccache");
+
 	/* the machine acct password might have change - fetch it every time */
 
 	SAFE_FREE(ads->auth.password);


-- 
Samba Shared Repository


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