Oracle provices advanced functionality for Oracle Label Security, such as the ability to analyze relationships between labels and querying for audited Oracle Label Security session labels. It also provides an Oracle Call Interface (OCI) for setting session labels.
Topics:
The relationship between two labels can be described in terms of dominance.
A user's ability to access an object depends on whether the user's label dominates the label of the object. If a user's label does not dominate the object's label, then the user is not allowed to access the object.
Label dominance is analyzed in terms of all its components: levels, compartments, and groups.
Table B-1 Dominance in the Comparison of Labels
| Factor | Criteria for Dominance |
|---|---|
|
Level |
For |
|
Compartment |
For |
|
Group |
For |
One label dominates another label if all of its components dominate the components of the other label. For example, the label HIGHLY_SENSITIVE:FINANCE,OPERATIONS dominates the label HIGHLY_SENSITIVE:FINANCE. Similarly, the label HIGHLY_SENSITIVE::WR_AP dominates the label HIGHLY_SENSITIVE::WR_AP, WR_AR.
See Also:
It is important to understand how labels can be compared with regard to dominance.
The relationship between two labels cannot always be defined by dominance. Two labels are non-comparable if neither label dominates the other.
If any compartments differ between the two labels (as with HS:A and HS:B), then they are non-comparable. Similarly, the labels HS:A and S:B are non-comparable.
You can find existing labels by querying the DBA_SA_LABELS data dictionary view.
Oracle Label Security provides a set of functions that you can use to control dominance.
Topics:
See Also:
You can use dominance functions to specify ranges in queries.
The following functions enable you to indicate dominance relationships between specified labels.
Table B-2 Functions to Determine Dominance
| Function | Description |
|---|---|
|
|
The value of |
|
|
The value of the session label for the corresponding |
|
|
The value of |
|
|
The value of |
|
|
The value of |
Note that there are two types of dominance function. While the SA_UTL dominance functions return BOOLEAN values, the standalone dominance functions return integers.
The OLS_DOMINATES (OLS_DOM) function returns 1 (TRUE) if label1 dominates label2, or 0 (FALSE) if it does not.
Syntax
OLS_DOMINATES ( label1 IN NUMBER, label2 IN NUMBER) RETURN INTEGER;
Parameters
Table B-3 OLS_DOMINATES Parameters
| Parameter | Description |
|---|---|
|
|
The first label to check. To find existing label values, query the |
|
|
The second label to check |
Example
The following example compares existing label tags 1111 and 1112.
SELECT OLS_DOMINATES ('1111', '1112') FROM DUAL;
OLS_DOMINATES('1111','1112')
----------------------------
0
Note:
The old OLS functions, DOMINATES and DOM, have been deprecated in Oracle Database 12c Release 1 (12.1).
You can still use the old functions in this release, but Oracle recommends that you use the OLS_LABEL_DOMINATES and OLS_DOM functions instead. Using the new function names avoids potential name conflicts with other database components.
The standalone OLS_LABEL_DOMINATES function returns 1 (TRUE) if the session label of the specified policy_name value dominates or is equal to the label that is specified by the label parameter; otherwise, it returns 0 (FALSE). This function is publicly available.
Note:
This feature is available starting with Oracle Database 12c Release 1 (12.1.0.2).
In addition to Oracle Label Security policies, you can use this function with both Oracle Data Redaction and Oracle Database Vault policies.
Syntax
OLS_LABEL_DOMINATES ( policy_name IN VARCHAR2, label IN VARCHAR2) RETURN INTEGER;
Parameters
Table B-4 OLS_LABEL_DOMINATES Parameters
| Parameter | Description |
|---|---|
|
|
The name of the Oracle Label Security policy whose session label must be checked for dominance. To find existing label values for policies, query the |
|
|
The base label against whom the dominance has to be checked |
Examples
The following example checks if the session label for the hr_ols_pol policy dominates or is equal to the hs label.
SELECT OLS_LABEL_DOMINATES ('hr_ols_pol', 'hs') FROM DUAL;
OLS_LABEL_DOMINATES('HR_OLS_POL','HS')
--------------------------------------
0
This example shows how you can use the OLS_LABEL_DOMINATES function in an Oracle Data Redaction policy:
BEGIN
DBMS_REDACT.ADD_POLICY(
object_schema => 'oe',
object_name => 'customers',
column_name => 'customer_id',
policy_name => 'redact_cust_user_ids',
function_type => DBMS_REDACT.FULL,
expression => 'OLS_LABEL_DOMINATES(''hr_ols_pol'', ''hs'') = 0');
END;
/
The following example shows how you can use the OLS_LABEL_DOMINATES function in an Oracle Database Vault rule definition:
EXEC DBMS_MACADM.CREATE_RULE('Check OLS Factor', 'OLS_LABEL_DOMINATES(''hr_ols_pol'', ''hs'') = 1');
See Also:
Oracle Database Advanced Security Guide for more information about Data Redaction
Oracle Database Vault Administrator's Guide for more information about Database Vault realms
The OLS_STRICTLY_DOMINATES (OLS_S_DOM) function returns 1 (TRUE) if label1 dominates label2 and is not equal to it.
Syntax
OLS_STRICTLY_DOMINATES ( label1 IN NUMBER, label2 IN NUMBER) RETURN INTEGER;
Parameters
Table B-5 OLS_STRICTLY_DOMINATES Parameters
| Parameter | Description |
|---|---|
|
|
The first label to check. To find existing label values, query the |
|
|
The second label to check |
Examples
The following example compares existing label tags 1111 and 1112.
SELECT OLS_STRICTLY_DOMINATES ('1111', '1112') FROM DUAL;
OLS_STRICTLY_DOMINATES('1111','1112')
-------------------------------------
0
Note:
The old OLS functions, STRICTLY_DOMINATES and S_DOM have been deprecated in Oracle Database 12c Release 1 (12.1).
You can still use the old functions in this release, but Oracle recommends that you use the OLS_STRICTLY_DOMINATES and OLS_S_DOM functions instead. Using the new function names avoids potential name conflicts with other database components.
Syntax
OLS_DOMINATED_BY ( label1 IN NUMBER, label2 IN NUMBER) RETURN INTEGER;
Parameters
Table B-6 OLS_STRICTLY_DOMINATES Parameters
| Parameter | Description |
|---|---|
|
|
The first label to check. To find existing label values, query the |
|
|
The second label to check |
Example
The following example compares existing label tags 1111 and 1112.
SELECT OLS_DOMINATED_BY ('1111', '1112') FROM DUAL;
OLS_DOMINATED_BY('1111','1112')
-------------------------------
1
Note:
The old OLS functions, DOMINATED_BY and DOM_BY have been deprecated in Oracle Database 12c Release 1 (12.1).
You can still use the old functions in this release, but Oracle recommends that you use the OLS_DOMINATED_BY and OLS_DOM_BY functions instead. Using the new function names avoids potential name conflicts with other database components.
The OLS_STRICTLY_DOMINATED_BY (OLS_S_DOM_BY) function returns 1 (TRUE) if label1 is dominated by label2 and is not equal to it.
Syntax
OLS_STRICTLY_DOMINATED_BY ( label1 IN NUMBER, label2 IN NUMBER) RETURN INTEGER;
Parameters
Table B-7 OLS_DOMINATES Parameters
| Parameter | Description |
|---|---|
|
|
The first label to check. To find existing label values, query the |
|
|
The second label to check |
Example
The following example compares existing label tags 1111 and 1112.
SELECT OLS_STRICTLY_DOMINATES ('1111', '1112') FROM DUAL;
OLS_STRICTLY_DOMINATES('1111','1112')
-------------------------------------
0
Note:
The old OLS functions, STRICTLY_DOMINATED_BY and S_DOM_BY have been deprecated in Oracle Database 12c Release 1 (12.1).
You can still use the old functions in this release, but Oracle recommends that you use the OLS_STRICTLY_DOMINATED_BY and OLS_S_DOM_BY functions instead. Using the new function names avoids potential name conflicts with other database components.
The SA_UTL.DOMINATES function returns TRUE if label1 dominates label2 or if the session label for the given OLS policy dominates label.
Syntax
SA_UTL.DOMINATES ( label1 IN NUMBER, label2 IN NUMBER) RETURN BOOLEAN;
Syntax
SA_UTL.DOMINATES ( ols_policy_name IN VARCHAR2, label IN VARCHAR2) RETURN BOOLEAN;
Parameters
Table B-8 SA_UTL.DOMINATES Parameters
| Parameter | Description |
|---|---|
|
|
The first label to check. To find existing label values, query the |
|
|
The second label to check |
Example
The following example compares existing label tags 1111 and 1112.
SET SERVEROUTPUT ON
BEGIN
IF SA_UTL.DOMINATES(1111, 1112)
THEN DBMS_OUTPUT.PUT_LINE('Label 1111 dominates label 1112.');
ELSE
DBMS_OUTPUT.PUT_LINE('Label 1112 dominates label 1111.');
END IF;
END;
/
Label 1112 dominates label 1111.
Note:
The second SA_UTL.DOMINATES function, which takes the Oracle Label Security policy name and label as inputs, has been deprecated in Oracle Database 12c Release 1 (12.1).
You can still use this function, but not with Oracle Data Redaction and Oracle Database Vault conditions. Oracle recommends that you use the OLS_LABEL_DOMINATES function instead.
The first SA_UTL.DOMINATES function, which uses the NUMBER datatype, is not deprecated.
The SA_UTL.STRICTLY_DOMINATES function returns TRUE if label1 dominates label2 and is not equal to it.
Syntax
SA_UTL.STRICTLY_DOMINATES ( label1 IN NUMBER, label2 IN NUMBER) RETURN BOOLEAN;
Parameters
Table B-9 SA_UTL.STRICTLY_DOMINATES Parameters
| Parameter | Description |
|---|---|
|
|
The first label to check. To find existing label values, query the |
|
|
The second label to check |
Example
The following example compares existing label tags 1111 and 1112.
SET SERVEROUTPUT ON
BEGIN
IF SA_UTL.STRICTLY_DOMINATES(1111, 1112)
THEN DBMS_OUTPUT.PUT_LINE('Label 1111 strictly dominates label 1112.');
ELSE
DBMS_OUTPUT.PUT_LINE('Label 1112 strictly dominates label 1111.');
END IF;
END;
/
Label 1112 strictly dominates label 1111.
Syntax
SA_UTL.DOMINATED_BY ( label1 IN NUMBER, label2 IN NUMBER) RETURN BOOLEAN;
Parameters
Table B-10 SA_UTL.DOMINATED_BY Parameters
| Parameter | Description |
|---|---|
|
|
The first label to check. To find existing label values, query the |
|
|
The second label to check |
Example
The following example compares existing label tags 1111 and 1112.
SET SERVEROUTPUT ON
BEGIN
IF SA_UTL.DOMINATED_BY(1111, 1112)
THEN DBMS_OUTPUT.PUT_LINE('Label 1111 is dominated by label 1112.');
ELSE
DBMS_OUTPUT.PUT_LINE('Label 1112 is dominated by label 1111.');
END IF;
END;
/
Label 1111 is dominated by label 1112.
The SA_UTL.STRICTLY_DOMINATED_BY function returns TRUE if label1 is dominated by label2 and is not equal to it.
Syntax
SA_UTL.STRICTLY_DOMINATED_BY ( label1 IN NUMBER, label2 IN NUMBER) RETURN BOOLEAN;
Parameters
Table B-11 SA_UTL.STRICTLY_DOMINATED_BY Parameters
| Parameter | Description |
|---|---|
|
|
The first label to check. To find existing label values, query the |
|
|
The second label to check |
Example
The following example compares existing label tags 1111 and 1112.
SET SERVEROUTPUT ON
BEGIN
IF SA_UTL.STRICTLY_DOMINATED_BY(1111, 1112)
THEN DBMS_OUTPUT.PUT_LINE('Label 1111 is strictly dominated by label 1112.');
ELSE
DBMS_OUTPUT.PUT_LINE('Label 1112 is strictly dominated by label 1111.');
END IF;
END;
/
Label 1111 is strictly dominated by label 1112.
See Also::
Oracle Database 12c uses a unified audit trail to capture information from various audit sources, including Oracle Label Security.
Topics:
You must configure OLS auditing by creating unified audit policies. OLS auditing in Oracle Database 12c enables you to audit additional events like enabling and disabling of OLS policies.
The session labels that the audit trail captures are stored in the APPLICATION_CONTEXTS column of the UNIFIED_AUDIT_TRAIL view. You can use the LBACSYS.ORA_GET_AUDITED_LABEL function to retrieve session labels that are stored in the APPLICATION_CONTEXTS column. This function accepts the UNIFIED_AUDIT_TRAIL.APPLICATION_CONTEXTS column value, and the Oracle Label Security policy name as arguments, and then returns the session label that is stored in the column for the specified policy.
See Oracle Database Security Guide for detailed information on configuring and using OLS auditing in Oracle Database 12c. The following section describes the ORA_GET_AUDITED_LABEL function.
The ORA_GET_AUDITED_LABEL function returns the audited session label for the specified OLS policy and APPLICATION_CONTEXTS column value. The AUDIT_VIEWER role has EXECUTE privilege on the ORA_GET_AUDITED_LABEL function.
Syntax
ORA_GET_AUDITED_LABEL ( appctx_col_value IN VARCHAR2, ols_policy_name IN VARCHAR2) RETURN VARCHAR2;
Parameters
Table B-12 ORA_GET_AUDITED_LABEL Parameters
| Parameter | Description |
|---|---|
|
|
Value in the |
|
|
The label security policy name |
Example
The following example returns the audited session label for the hr_ols_pol policy.
SELECT ORA_GET_AUDITED_LABEL ('cust_ctx', 'hr_ols_pol') FROM DUAL;
ORA_GET_AUDITED_LABEL('X','HR_OLS_POL')
---------------------------------------
HS
You can use an Oracle Call Interface (OCI) to set session labels.
Topics:
When you connect using Oracle Call Interface (OCI), you can use the system SYS_CONTEXT variables to initialize the session label and the row label.
You can set the variables using the OCIAttrSet function to initialize externally initialized SYS_CONTEXT variables. These are available when Oracle Label Security is enabled.
Each policy has a SYS_CONTEXT named SA$policy_name_X. You can set these two variables, INITIAL_LABEL and INITIAL_ROW_LABEL.
When the new values are set to valid labels within the user's authorizations, they will be used instead of the default values stored for the user. This is the same mechanism used for remote connections.
You can use the Oracle Call Interface to set the session labels.
Example B-1 shows how to use externalized SYS_CONTEXT with Oracle Label Security.
Example B-1 Using OCI to Externalize SYS_CONTEXT with OLS
#ifdef RCSID
static char *RCSid =
"$Header: ext_mls.c 09-may-00.10:07:08 jdoe Exp $ ";
#endif /* RCSID */
/* Copyright (c) Oracle Corporation 1999, 2000. All Rights Reserved. */
/*
NAME
ext_mls.c - externalized SYS_CONTEXT with Label Security
DESCRIPTION
Run olsdemo.sql script before executing this example.
Usage: <executable obtained with .c file> <user_name> <password> <session-initial-label
Example: avg_sal sa_demo sa_demo L3:M,E:D10
PUBLIC FUNCTION(S)
<list of external functions declared/defined - with one-line descriptions>
PRIVATE FUNCTION(S)
<list of static functions defined in .c file - with one-line descriptions>
RETURNS
The average salary in the EMP table of the SA_DEMO schema querying as the specified user with the specified session label.
NOTES
<other useful comments, qualifications, and so on>
MODIFIED (MM/DD/YY)
jlev 09/18/03 - cleanup
jdoe 05/09/00 - cleanup
jdoe 10/13/99 - standalone OCI program to test MLS SYS_CONTEXT
jdoe 10/13/99 - Creation
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <oci.h>
static OCIEnv *envhp;
static OCIError *errhp;
int main(/*_ int argc, char *argv[] _*/);
/* get and print error */
static void checkerr(/*_OCIError *errhp, sword status _*/);
/* print error */
static void printerr(char *call);
static sword status;
/* return the average of employees' salary */
static CONST text *const selectstmt = (text *)
"select avg(sal) from sa_demo.emp";
int main(argc, argv)
int argc;
char *argv[];
{
OCISession *authp = (OCISession *) 0;
OCIServer *srvhp;
OCISvcCtx *svchp;
OCIDefine *defnp = (OCIDefine *) 0;
dvoid *parmdp;
ub4 ctxsize;
OCIParam *ctxldesc;
OCIParam *ctxedesc;
OCIStmt *stmtp = (OCIStmt *) 0;
ub4 avg_sal = 0;
sword status;
if (OCIInitialize((ub4) OCI_DEFAULT, (dvoid *) 0,
(dvoid * (*)(dvoid *, size_t)) 0,
(dvoid * (*)(dvoid *, dvoid *, size_t)) 0,
(void (*)(dvoid *, dvoid *)) 0))
printerr("OCIInitialize");
if (OCIEnvInit((OCIEnv **) &envhp, OCI_DEFAULT, (size_t) 0, (dvoid **) 0))
printerr("OCIEnvInit");
if (OCIHandleAlloc((dvoid *) envhp, (dvoid **) &errhp, OCI_HTYPE_ERROR,
(size_t) 0, (dvoid **) 0))
printerr("OCIHandleAlloc:OCI_HTYPE_ERROR");
if (OCIHandleAlloc((dvoid *) envhp, (dvoid **) &srvhp, OCI_HTYPE_SERVER,
(size_t) 0, (dvoid **) 0))
printerr("OCIHandleAlloc:OCI_HTYPE_SERVER");
if (OCIHandleAlloc((dvoid *) envhp, (dvoid **) &svchp, OCI_HTYPE_SVCCTX,
(size_t) 0, (dvoid **) 0))
printerr("OCIHandleAlloc:OCI_HTYPE_SVCCTX");
if (OCIServerAttach(srvhp, errhp, (text *) "", strlen(""), 0))
printerr("OCIServerAttach");
/* set attribute server context in the service context */
if (OCIAttrSet((dvoid *) svchp, OCI_HTYPE_SVCCTX, (dvoid *) srvhp,
(ub4) 0, OCI_ATTR_SERVER, (OCIError *) errhp))
printerr("OCIAttrSet:OCI_HTYPE_SVCCTX");
if (OCIHandleAlloc((dvoid *) envhp, (dvoid **) &authp,
(ub4) OCI_HTYPE_SESSION, (size_t) 0, (dvoid **) 0))
printerr("OCIHandleAlloc:OCI_HTYPE_SESSION");
/* set application context to 1 */
ctxsize = 1;
/* set up app ctx buffer */
if (OCIAttrSet((dvoid *) authp, (ub4) OCI_HTYPE_SESSION, (dvoid *) &ctxsize,
(ub4) 0, (ub4) OCI_ATTR_APPCTX_SIZE, errhp))
printerr("OCIAttrSet:OCI_ATTR_APPCTX_SIZE");
/* retrieve the list descriptor */
if (OCIAttrGet((dvoid *) authp, (ub4) OCI_HTYPE_SESSION,
(dvoid *) &ctxldesc, 0, OCI_ATTR_APPCTX_LIST, errhp))
printerr("OCIAttrGet:OCI_ATTR_APPCTX_LIST");
if (status = OCIParamGet(ctxldesc, OCI_DTYPE_PARAM, errhp,
(dvoid **) &ctxedesc, 1))
{
if (status == OCI_NO_DATA)
{
printf("No Data found!\n");
exit(1);
}
}
/* set context namespace to SA$<pol_name>_X */
if (OCIAttrSet((dvoid *) ctxedesc, (ub4) OCI_DTYPE_PARAM,
(dvoid *) "SA$HUMAN_RESOURCES_X",
(ub4) strlen((char *) "SA$HUMAN_RESOURCES_X"),
(ub4) OCI_ATTR_APPCTX_NAME, errhp))
printerr("OCIAttrSet:OCI_ATTR_APPCTX_NAME:SA$HUMAN_RESOURCES_X");
/* set context attribute to INITIAL_LABEL */
if (OCIAttrSet((dvoid *) ctxedesc, (ub4) OCI_DTYPE_PARAM,
(dvoid *) "INITIAL_LABEL",
(ub4) strlen((char *) "INITIAL_LABEL"),
(ub4) OCI_ATTR_APPCTX_ATTR, errhp))
printerr("OCIAttrSet:OCI_DTYPE_PARAM:INITIAL_LABEL");
/* set context value to argv[3] - initial label */
if (OCIAttrSet((dvoid *) ctxedesc, (ub4) OCI_DTYPE_PARAM,
(dvoid *) argv[3],
(ub4) strlen((char *) argv[3]),
(ub4) OCI_ATTR_APPCTX_VALUE, errhp))
printerr("OCIAttrSet:argv[3]");
/* username first command line argument */
if (OCIAttrSet((dvoid *) authp, (ub4) OCI_HTYPE_SESSION, (dvoid *) argv[1],
(ub4) strlen((char *) argv[1]), (ub4) OCI_ATTR_USERNAME,
errhp))
printerr("OCIAttrSet:username");
/* password second command line argument */
if (OCIAttrSet((dvoid *) authp, (ub4) OCI_HTYPE_SESSION, (dvoid *) argv[2],
(ub4) strlen((char *) argv[2]), (ub4) OCI_ATTR_PASSWORD,
errhp))
printerr("OCIAttrSet:password");
if (OCISessionBegin(svchp, errhp, authp, OCI_CRED_RDBMS, (ub4) OCI_DEFAULT))
printerr("OCISessionBegin");
if (OCIAttrSet((dvoid *) svchp, (ub4) OCI_HTYPE_SVCCTX, (dvoid *) authp,
(ub4) 0, (ub4) OCI_ATTR_SESSION, errhp))
printerr("OCIAttrSet:OCI_ATTR_SESSION");
if (OCIHandleAlloc((dvoid *) envhp, (dvoid **) &stmtp, OCI_HTYPE_STMT,
0, 0))
printerr("OCIHandleAlloc:OCI_HTYPE_STMT");
if (OCIStmtPrepare(stmtp, errhp, (CONST OraText *) selectstmt,
(ub4) strlen((const char *) selectstmt),
(ub4) OCI_NTV_SYNTAX, (ub4) OCI_DEFAULT))
printerr("OCIStmtPrepare");
if (OCIDefineByPos(stmtp, &defnp, errhp, (ub4) 1, (dvoid *) &avg_sal,
(sb4) sizeof(avg_sal), SQLT_INT, 0, 0, 0, OCI_DEFAULT))
printerr("OCIDefineByPos");
if (status = OCIStmtExecute(svchp, stmtp, errhp, 1, 0, NULL, NULL,
OCI_DEFAULT))
{
if (status == OCI_NO_DATA)
{
printf("No Data found!\n");
exit(1);
}
}
if (OCISessionEnd(svchp, errhp, authp, OCI_DEFAULT))
printerr("OCISessionEnd");
printf("average salary is: %d\n", avg_sal);
}
void checkerr(errhp, status)
OCIError *errhp;
sword status;
{
text errbuf[512];
sb4 errcode = 0;
switch (status)
{
case OCI_ERROR:
(void) OCIErrorGet((dvoid *) errhp, 1, NULL, &errcode, errbuf,
(ub4) sizeof(errbuf), OCI_HTYPE_ERROR);
printf("Error - %.*s\n", 512, errbuf);
break;
default:
break;
}
}
void printerr(call)
char *call;
{
printf("Error: %s\n", call);
}
/* end of file ext_mls.c */