Interface AccessController
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- All Known Implementing Classes:
DefaultAccessController
,ExperimentalAccessController
public interface AccessController
The AccessController interface defines a set of methods that can be used in a wide variety of applications to enforce access control. In most applications, access control must be performed in multiple different locations across the various application layers. This class provides access control for URLs, business functions, data, services, and files.The implementation of this interface will need to access the current User object (from Authenticator.getCurrentUser()) to determine roles or permissions. In addition, the implementation will also need information about the resources that are being accessed. Using the user information and the resource information, the implementation should return an access control decision.
Implementers are encouraged to implement the ESAPI access control rules, like assertAuthorizedForFunction() using existing access control mechanisms, such as methods like isUserInRole() or hasPrivilege(). While powerful, methods like isUserInRole() can be confusing for developers, as users may be in multiple roles or possess multiple overlapping privileges. Direct use of these finer grained access control methods encourages the use of complex boolean tests throughout the code, which can easily lead to developer mistakes.
The point of the ESAPI access control interface is to centralize access control logic behind easy to use calls like assertAuthorized() so that access control is easy to use and easy to verify. Here is an example of a very straightforward to implement, understand, and verify ESAPI access control check:
try { ESAPI.accessController().assertAuthorized("businessFunction", runtimeData); // execute BUSINESS_FUNCTION } catch (AccessControlException ace) { ... attack in progress }
Note that in the user interface layer, access control checks can be used to control whether particular controls are rendered or not. These checks are supposed to fail when an unauthorized user is logged in, and do not represent attacks. Remember that regardless of how the user interface appears, an attacker can attempt to invoke any business function or access any data in your application. Therefore, access control checks in the user interface should be repeated in both the business logic and data layers.<% if ( ESAPI.accessController().isAuthorized( "businessFunction", runtimeData ) ) { %> <a href="/doAdminFunction">ADMIN</a> <% } else { %> <a href="/doNormalFunction">NORMAL</a> <% } %>
- Author:
- Mike H. Fauzy (mike.fauzy@aspectsecurity.com) ESAPI v1.6-, Jeff Williams (jeff.williams@aspectsecurity.com) ESAPI v0-1.5
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description void
assertAuthorized(java.lang.Object key, java.lang.Object runtimeParameter)
assertAuthorized
executes theAccessControlRule
that is identified bykey
and listed in theresources/ESAPI-AccessControlPolicy.xml
file.void
assertAuthorizedForData(java.lang.String action, java.lang.Object data)
Checks if the current user is authorized to access the referenced data.void
assertAuthorizedForFile(java.lang.String filepath)
Checks if the current user is authorized to access the referenced file.void
assertAuthorizedForFunction(java.lang.String functionName)
Checks if the current user is authorized to access the referenced function.void
assertAuthorizedForService(java.lang.String serviceName)
Checks if the current user is authorized to access the referenced service.void
assertAuthorizedForURL(java.lang.String url)
Checks if the current user is authorized to access the referenced URL.boolean
isAuthorized(java.lang.Object key, java.lang.Object runtimeParameter)
isAuthorized
executes theAccessControlRule
that is identified bykey
and listed in theresources/ESAPI-AccessControlPolicy.xml
file.boolean
isAuthorizedForData(java.lang.String action, java.lang.Object data)
Checks if the current user is authorized to access the referenced data, represented as an Object.boolean
isAuthorizedForFile(java.lang.String filepath)
Checks if the current user is authorized to access the referenced file.boolean
isAuthorizedForFunction(java.lang.String functionName)
Checks if the current user is authorized to access the referenced function.boolean
isAuthorizedForService(java.lang.String serviceName)
Checks if the current user is authorized to access the referenced service.boolean
isAuthorizedForURL(java.lang.String url)
Checks if the current user is authorized to access the referenced URL.
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Method Detail
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isAuthorized
boolean isAuthorized(java.lang.Object key, java.lang.Object runtimeParameter)
isAuthorized
executes theAccessControlRule
that is identified bykey
and listed in theresources/ESAPI-AccessControlPolicy.xml
file. It returns true if theAccessControlRule
decides that the operation should be allowed. Otherwise, it returns false. Any exception thrown by theAccessControlRule
must result in false. Ifkey
does not map to anAccessControlRule
, then false is returned. Developers should call isAuthorized to control execution flow. For example, if you want to decide whether to display a UI widget in the browser using the same logic that you will use to enforce permissions on the server, then isAuthorized is the method that you want to use. Typically, assertAuthorized should be used to enforce permissions on the server.- Parameters:
key
-key
maps to<AccessControlPolicy><AccessControlRules> <AccessControlRule name="key"
runtimeParameter
- runtimeParameter can contain anything that the AccessControlRule needs from the runtime system.- Returns:
- Returns
true
if and only if the AccessControlRule specified bykey
exists and returnedtrue
. Otherwise returnsfalse
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assertAuthorized
void assertAuthorized(java.lang.Object key, java.lang.Object runtimeParameter) throws AccessControlException
assertAuthorized
executes theAccessControlRule
that is identified bykey
and listed in theresources/ESAPI-AccessControlPolicy.xml
file. It does nothing if theAccessControlRule
decides that the operation should be allowed. Otherwise, it throws anorg.owasp.esapi.errors.AccessControlException
. Any exception thrown by theAccessControlRule
will also result in anAccesControlException
. Ifkey
does not map to anAccessControlRule
, then anAccessControlException
is thrown. Developers should callassertAuthorized
to enforce privileged access to the system. It should be used to answer the question: "Should execution continue." Ideally, the call toassertAuthorized
should be integrated into the application framework so that it is called automatically.- Parameters:
key
-key
maps to <AccessControlPolicy><AccessControlRules> <AccessControlRule name="key"runtimeParameter
- runtimeParameter can contain anything that the AccessControlRule needs from the runtime system.- Throws:
AccessControlException
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isAuthorizedForURL
boolean isAuthorizedForURL(java.lang.String url)
Checks if the current user is authorized to access the referenced URL. Generally, this method should be invoked in the application's controller or a filter as follows:ESAPI.accessController().isAuthorizedForURL(request.getRequestURI().toString());
The implementation of this method should call assertAuthorizedForURL(String url), and if an AccessControlException is not thrown, this method should return true. This way, if the user is not authorized, false would be returned, and the exception would be logged.- Parameters:
url
- the URL as returned by request.getRequestURI().toString()- Returns:
- true, if is authorized for URL
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isAuthorizedForFunction
boolean isAuthorizedForFunction(java.lang.String functionName)
Checks if the current user is authorized to access the referenced function. The implementation of this method should call assertAuthorizedForFunction(String functionName), and if an AccessControlException is not thrown, this method should return true.- Parameters:
functionName
- the name of the function- Returns:
- true, if is authorized for function
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isAuthorizedForData
boolean isAuthorizedForData(java.lang.String action, java.lang.Object data)
Checks if the current user is authorized to access the referenced data, represented as an Object. The implementation of this method should call assertAuthorizedForData(String action, Object data), and if an AccessControlException is not thrown, this method should return true.- Parameters:
action
- The action to verify for an access control decision, such as a role, or an action being performed on the object (e.g., Read, Write, etc.), or the name of the function the data is being passed to.data
- The actual object or object identifier being accessed or a reference to the object being accessed.- Returns:
- true, if is authorized for the data
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isAuthorizedForFile
boolean isAuthorizedForFile(java.lang.String filepath)
Checks if the current user is authorized to access the referenced file. The implementation of this method should call assertAuthorizedForFile(String filepath), and if an AccessControlException is not thrown, this method should return true.- Parameters:
filepath
- the path of the file to be checked, including filename- Returns:
- true, if is authorized for the file
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isAuthorizedForService
boolean isAuthorizedForService(java.lang.String serviceName)
Checks if the current user is authorized to access the referenced service. This can be used in applications that provide access to a variety of back end services. The implementation of this method should call assertAuthorizedForService(String serviceName), and if an AccessControlException is not thrown, this method should return true.- Parameters:
serviceName
- the service name- Returns:
- true, if is authorized for the service
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assertAuthorizedForURL
void assertAuthorizedForURL(java.lang.String url) throws AccessControlException
Checks if the current user is authorized to access the referenced URL. The implementation should allow access to be granted to any part of the URL. Generally, this method should be invoked in the application's controller or a filter as follows:ESAPI.accessController().assertAuthorizedForURL(request.getRequestURI().toString());
This method throws an AccessControlException if access is not authorized, or if the referenced URL does not exist. If the User is authorized, this method simply returns.Specification: The implementation should do the following:
- Check to see if the resource exists and if not, throw an AccessControlException
- Use available information to make an access control decision
- Ideally, this policy would be data driven
- You can use the current User, roles, data type, data name, time of day, etc.
- Access control decisions must deny by default
- If access is not permitted, throw an AccessControlException with details
- Parameters:
url
- the URL as returned by request.getRequestURI().toString()- Throws:
AccessControlException
- if access is not permitted
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assertAuthorizedForFunction
void assertAuthorizedForFunction(java.lang.String functionName) throws AccessControlException
Checks if the current user is authorized to access the referenced function. The implementation should define the function "namespace" to be enforced. Choosing something simple like the class name of action classes or menu item names will make this implementation easier to use.This method throws an AccessControlException if access is not authorized, or if the referenced function does not exist. If the User is authorized, this method simply returns.
Specification: The implementation should do the following:
- Check to see if the function exists and if not, throw an AccessControlException
- Use available information to make an access control decision
- Ideally, this policy would be data driven
- You can use the current User, roles, data type, data name, time of day, etc.
- Access control decisions must deny by default
- If access is not permitted, throw an AccessControlException with details
- Parameters:
functionName
- the function name- Throws:
AccessControlException
- if access is not permitted
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assertAuthorizedForData
void assertAuthorizedForData(java.lang.String action, java.lang.Object data) throws AccessControlException
Checks if the current user is authorized to access the referenced data. This method simply returns if access is authorized. It throws an AccessControlException if access is not authorized, or if the referenced data does not exist.Specification: The implementation should do the following:
- Check to see if the resource exists and if not, throw an AccessControlException
- Use available information to make an access control decision
- Ideally, this policy would be data driven
- You can use the current User, roles, data type, data name, time of day, etc.
- Access control decisions must deny by default
- If access is not permitted, throw an AccessControlException with details
- Parameters:
action
- The action to verify for an access control decision, such as a role, or an action being performed on the object (e.g., Read, Write, etc.), or the name of the function the data is being passed to.data
- The actual object or object identifier being accessed or a reference to the object being accessed.- Throws:
AccessControlException
- if access is not permitted
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assertAuthorizedForFile
void assertAuthorizedForFile(java.lang.String filepath) throws AccessControlException
Checks if the current user is authorized to access the referenced file. The implementation should validate and canonicalize the input to be sure the filepath is not malicious.This method throws an AccessControlException if access is not authorized, or if the referenced File does not exist. If the User is authorized, this method simply returns.
Specification: The implementation should do the following:
- Check to see if the File exists and if not, throw an AccessControlException
- Use available information to make an access control decision
- Ideally, this policy would be data driven
- You can use the current User, roles, data type, data name, time of day, etc.
- Access control decisions must deny by default
- If access is not permitted, throw an AccessControlException with details
- Parameters:
filepath
- Path to the file to be checked- Throws:
AccessControlException
- if access is denied
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assertAuthorizedForService
void assertAuthorizedForService(java.lang.String serviceName) throws AccessControlException
Checks if the current user is authorized to access the referenced service. This can be used in applications that provide access to a variety of backend services.This method throws an AccessControlException if access is not authorized, or if the referenced service does not exist. If the User is authorized, this method simply returns.
Specification: The implementation should do the following:
- Check to see if the service exists and if not, throw an AccessControlException
- Use available information to make an access control decision
- Ideally, this policy would be data driven
- You can use the current User, roles, data type, data name, time of day, etc.
- Access control decisions must deny by default
- If access is not permitted, throw an AccessControlException with details
- Parameters:
serviceName
- the service name- Throws:
AccessControlException
- if access is not permitted
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