SecureASTCustomizer (Groovy 2.4.3)

java.lang.Object
- org.codehaus.groovy.control.CompilationUnit.PrimaryClassNodeOperation
- - org.codehaus.groovy.control.customizers.CompilationCustomizer
  - - org.codehaus.groovy.control.customizers.SecureASTCustomizer

public class SecureASTCustomizer
extends CompilationCustomizer

This customizer allows securing source code by controlling what code constructs are allowed. For example, if you only want to allow arithmetic operations in a groovy shell, you can configure this customizer to restrict package imports, method calls and so on.

Most of the securization options found in this class work with either blacklist or whitelist. This means that, for a single option, you can set a whitelist OR a blacklist, but not both. You can mix whitelist/blacklist strategies for different options. For example, you can have import whitelist and tokens blacklist.

The recommanded way of securing shells is to use whitelists because it is guaranteed that future features of the Groovy language won't be allowed by defaut. Using blacklists, you can limit the features of the languages by opting out, but new language features would require you to update your configuration.

If you set neither a whitelist nor a blacklist, then everything is authorized.

Combinations of import and star imports constraints are authorized as long as you use the same type of list for both. For example, you may use an import whitelist and a star import whitelist together, but you cannot use an import white list with a star import blacklist. static imports are handled separately, meaning that blacklisting an import does not prevent from using a static import.

Eventually, if the features provided here are not sufficient, you may implement custom AST filtering handlers, either implementing the SecureASTCustomizer.StatementChecker interface or SecureASTCustomizer.ExpressionChecker interface then register your handlers thanks to the addExpressionCheckers(org.codehaus.groovy.control.customizers.SecureASTCustomizer.ExpressionChecker...) and addStatementCheckers(org.codehaus.groovy.control.customizers.SecureASTCustomizer.StatementChecker...) methods.

Here is an example of usage. We will create a groovy classloader which only supports arithmetic operations and imports the java.lang.Math classes by default.

 final ImportCustomizer imports = new ImportCustomizer().addStaticStars('java.lang.Math') // add static import of java.lang.Math
             final SecureASTCustomizer secure = new SecureASTCustomizer()
             secure.with {
                 closuresAllowed = false
                 methodDefinitionAllowed = false

                 importsWhitelist = []
                 staticImportsWhitelist = []
                 staticStarImportsWhitelist = ['java.lang.Math'] // only java.lang.Math is allowed

                 tokensWhitelist = [
                         PLUS,
                         MINUS,
                         MULTIPLY,
                         DIVIDE,
                         MOD,
                         POWER,
                         PLUS_PLUS,
                         MINUS_MINUS,
                         COMPARE_EQUAL,
                         COMPARE_NOT_EQUAL,
                         COMPARE_LESS_THAN,
                         COMPARE_LESS_THAN_EQUAL,
                         COMPARE_GREATER_THAN,
                         COMPARE_GREATER_THAN_EQUAL,
                 ].asImmutable()

                 constantTypesClassesWhiteList = [
                         Integer,
                         Float,
                         Long,
                         Double,
                         BigDecimal,
                         Integer.TYPE,
                         Long.TYPE,
                         Float.TYPE,
                         Double.TYPE
                 ].asImmutable()

                 receiversClassesWhiteList = [
                         Math,
                         Integer,
                         Float,
                         Double,
                         Long,
                         BigDecimal
                 ].asImmutable()
             }
             CompilerConfiguration config = new CompilerConfiguration()
             config.addCompilationCustomizers(imports, secure)
             GroovyClassLoader loader = new GroovyClassLoader(this.class.classLoader, config)

Since:: 1.8.0
Author:: Cedric Champeau, Guillaume Laforge, Hamlet D'Arcy

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static interface`	`SecureASTCustomizer.ExpressionChecker` This interface allows the user to plugin custom expression checkers if expression blacklist or whitelist are not sufficient
`static interface`	`SecureASTCustomizer.StatementChecker` This interface allows the user to plugin custom statement checkers if statement blacklist or whitelist are not sufficient

Constructor Summary

Constructors
Constructor and Description

SecureASTCustomizer()

Constructors
Constructor and Description
`SecureASTCustomizer()`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addExpressionCheckers(SecureASTCustomizer.ExpressionChecker... checkers)`
`void`	`addStatementCheckers(SecureASTCustomizer.StatementChecker... checkers)`
`void`	`call(SourceUnit source, GeneratorContext context, ClassNode classNode)`
`List<String>`	`getConstantTypesBlackList()`
`List<String>`	`getConstantTypesWhiteList()`
`List<Class<? extends Expression>>`	`getExpressionsBlacklist()`
`List<Class<? extends Expression>>`	`getExpressionsWhitelist()`
`List<String>`	`getImportsBlacklist()`
`List<String>`	`getImportsWhitelist()`
`List<String>`	`getReceiversBlackList()`
`List<String>`	`getReceiversWhiteList()`
`List<String>`	`getStarImportsBlacklist()`
`List<String>`	`getStarImportsWhitelist()`
`List<Class<? extends Statement>>`	`getStatementsBlacklist()`
`List<Class<? extends Statement>>`	`getStatementsWhitelist()`
`List<String>`	`getStaticImportsBlacklist()`
`List<String>`	`getStaticImportsWhitelist()`
`List<String>`	`getStaticStarImportsBlacklist()`
`List<String>`	`getStaticStarImportsWhitelist()`
`List<Integer>`	`getTokensBlacklist()`
`List<Integer>`	`getTokensWhitelist()`
`boolean`	`isClosuresAllowed()`
`boolean`	`isIndirectImportCheckEnabled()`
`boolean`	`isMethodDefinitionAllowed()`
`boolean`	`isPackageAllowed()`
`void`	`setClosuresAllowed(boolean closuresAllowed)`
`void`	`setConstantTypesBlackList(List<String> constantTypesBlackList)`
`void`	`setConstantTypesClassesBlackList(List<Class> constantTypesBlackList)` An alternative way of setting constant types.
`void`	`setConstantTypesClassesWhiteList(List<Class> constantTypesWhiteList)` An alternative way of setting constant types.
`void`	`setConstantTypesWhiteList(List<String> constantTypesWhiteList)`
`void`	`setExpressionsBlacklist(List<Class<? extends Expression>> expressionsBlacklist)`
`void`	`setExpressionsWhitelist(List<Class<? extends Expression>> expressionsWhitelist)`
`void`	`setImportsBlacklist(List<String> importsBlacklist)`
`void`	`setImportsWhitelist(List<String> importsWhitelist)`
`void`	`setIndirectImportCheckEnabled(boolean indirectImportCheckEnabled)` Set this option to true if you want your import rules to be checked against every class node.
`void`	`setMethodDefinitionAllowed(boolean methodDefinitionAllowed)`
`void`	`setPackageAllowed(boolean packageAllowed)`
`void`	`setReceiversBlackList(List<String> receiversBlackList)` Sets the list of classes which deny method calls.
`void`	`setReceiversClassesBlackList(List<Class> receiversBlacklist)` An alternative way of setting `receiver classes`.
`void`	`setReceiversClassesWhiteList(List<Class> receiversWhitelist)` An alternative way of setting `receiver classes`.
`void`	`setReceiversWhiteList(List<String> receiversWhiteList)` Sets the list of classes which may accept method calls.
`void`	`setStarImportsBlacklist(List<String> starImportsBlacklist)`
`void`	`setStarImportsWhitelist(List<String> starImportsWhitelist)`
`void`	`setStatementsBlacklist(List<Class<? extends Statement>> statementsBlacklist)`
`void`	`setStatementsWhitelist(List<Class<? extends Statement>> statementsWhitelist)`
`void`	`setStaticImportsBlacklist(List<String> staticImportsBlacklist)`
`void`	`setStaticImportsWhitelist(List<String> staticImportsWhitelist)`
`void`	`setStaticStarImportsBlacklist(List<String> staticStarImportsBlacklist)`
`void`	`setStaticStarImportsWhitelist(List<String> staticStarImportsWhitelist)`
`void`	`setTokensBlacklist(List<Integer> tokensBlacklist)` Sets the list of tokens which are blacklisted.
`void`	`setTokensWhitelist(List<Integer> tokensWhitelist)` Sets the list of tokens which are whitelisted.

Methods inherited from class org.codehaus.groovy.control.customizers.CompilationCustomizer
getPhase

Methods inherited from class org.codehaus.groovy.control.CompilationUnit.PrimaryClassNodeOperation
needSortedInput

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail
- SecureASTCustomizer
```
public SecureASTCustomizer()
```

Method Detail

isMethodDefinitionAllowed

public boolean isMethodDefinitionAllowed()

setMethodDefinitionAllowed

public void setMethodDefinitionAllowed(boolean methodDefinitionAllowed)

isPackageAllowed
```
public boolean isPackageAllowed()
```

isClosuresAllowed
```
public boolean isClosuresAllowed()
```

setClosuresAllowed

public void setClosuresAllowed(boolean closuresAllowed)

setPackageAllowed

public void setPackageAllowed(boolean packageAllowed)

getImportsBlacklist

public List<String> getImportsBlacklist()

setImportsBlacklist

public void setImportsBlacklist(List<String> importsBlacklist)

getImportsWhitelist

public List<String> getImportsWhitelist()

setImportsWhitelist

public void setImportsWhitelist(List<String> importsWhitelist)

getStarImportsBlacklist

public List<String> getStarImportsBlacklist()

setStarImportsBlacklist

public void setStarImportsBlacklist(List<String> starImportsBlacklist)

getStarImportsWhitelist

public List<String> getStarImportsWhitelist()

setStarImportsWhitelist

public void setStarImportsWhitelist(List<String> starImportsWhitelist)

getStaticImportsBlacklist

public List<String> getStaticImportsBlacklist()

setStaticImportsBlacklist

public void setStaticImportsBlacklist(List<String> staticImportsBlacklist)

getStaticImportsWhitelist

public List<String> getStaticImportsWhitelist()

setStaticImportsWhitelist

public void setStaticImportsWhitelist(List<String> staticImportsWhitelist)

getStaticStarImportsBlacklist

public List<String> getStaticStarImportsBlacklist()

setStaticStarImportsBlacklist

public void setStaticStarImportsBlacklist(List<String> staticStarImportsBlacklist)

getStaticStarImportsWhitelist

public List<String> getStaticStarImportsWhitelist()

setStaticStarImportsWhitelist

public void setStaticStarImportsWhitelist(List<String> staticStarImportsWhitelist)

getExpressionsBlacklist

public List<Class<? extends Expression>> getExpressionsBlacklist()

setExpressionsBlacklist

public void setExpressionsBlacklist(List<Class<? extends Expression>> expressionsBlacklist)

getExpressionsWhitelist

public List<Class<? extends Expression>> getExpressionsWhitelist()

setExpressionsWhitelist

public void setExpressionsWhitelist(List<Class<? extends Expression>> expressionsWhitelist)

getStatementsBlacklist

public List<Class<? extends Statement>> getStatementsBlacklist()

setStatementsBlacklist

public void setStatementsBlacklist(List<Class<? extends Statement>> statementsBlacklist)

getStatementsWhitelist

public List<Class<? extends Statement>> getStatementsWhitelist()

setStatementsWhitelist

public void setStatementsWhitelist(List<Class<? extends Statement>> statementsWhitelist)

getTokensBlacklist

public List<Integer> getTokensBlacklist()

isIndirectImportCheckEnabled

public boolean isIndirectImportCheckEnabled()

setIndirectImportCheckEnabled
```
public void setIndirectImportCheckEnabled(boolean indirectImportCheckEnabled)
```
Set this option to true if you want your import rules to be checked against every class node. This means that if someone uses a fully qualified class name, then it will also be checked against the import rules, preventing, for example, instantiation of classes without imports thanks to FQCN.

Parameters:
indirectImportCheckEnabled - set to true to enable indirect checks

setTokensBlacklist
```
public void setTokensBlacklist(List<Integer> tokensBlacklist)
```
Sets the list of tokens which are blacklisted.

Parameters:
tokensBlacklist - the tokens. The values of the tokens must be those of Types

getTokensWhitelist

public List<Integer> getTokensWhitelist()

setTokensWhitelist
```
public void setTokensWhitelist(List<Integer> tokensWhitelist)
```
Sets the list of tokens which are whitelisted.

Parameters:
tokensWhitelist - the tokens. The values of the tokens must be those of Types

addStatementCheckers

public void addStatementCheckers(SecureASTCustomizer.StatementChecker... checkers)

addExpressionCheckers

public void addExpressionCheckers(SecureASTCustomizer.ExpressionChecker... checkers)

getConstantTypesBlackList

public List<String> getConstantTypesBlackList()

setConstantTypesBlackList

public void setConstantTypesBlackList(List<String> constantTypesBlackList)

getConstantTypesWhiteList

public List<String> getConstantTypesWhiteList()

setConstantTypesWhiteList

public void setConstantTypesWhiteList(List<String> constantTypesWhiteList)

setConstantTypesClassesWhiteList
```
public void setConstantTypesClassesWhiteList(List<Class> constantTypesWhiteList)
```
An alternative way of setting constant types.

Parameters:
constantTypesWhiteList - a list of classes.

setConstantTypesClassesBlackList
```
public void setConstantTypesClassesBlackList(List<Class> constantTypesBlackList)
```
An alternative way of setting constant types.

Parameters:
constantTypesBlackList - a list of classes.

getReceiversBlackList

public List<String> getReceiversBlackList()

setReceiversBlackList
```
public void setReceiversBlackList(List<String> receiversBlackList)
```
Sets the list of classes which deny method calls. Please note that since Groovy is a dynamic language, and this class performs a static type check, it will be reletively simple to bypass any blacklist unless the receivers blacklist contains, at a minimum, Object, Script, GroovyShell, and Eval. Additionally, it is necessary to also blacklist MethodPointerExpression in the expressions blacklist for the receivers blacklist to function as a security check.

Parameters:
receiversBlackList - the list of refused classes, as fully qualified names

setReceiversClassesBlackList
```
public void setReceiversClassesBlackList(List<Class> receiversBlacklist)
```
An alternative way of setting receiver classes.

Parameters:
receiversBlacklist - a list of classes.

getReceiversWhiteList

public List<String> getReceiversWhiteList()

setReceiversWhiteList
```
public void setReceiversWhiteList(List<String> receiversWhiteList)
```
Sets the list of classes which may accept method calls.

Parameters:
receiversWhiteList - the list of accepted classes, as fully qualified names

setReceiversClassesWhiteList
```
public void setReceiversClassesWhiteList(List<Class> receiversWhitelist)
```
An alternative way of setting receiver classes.

Parameters:
receiversWhitelist - a list of classes.

call

public void call(SourceUnit source,
        GeneratorContext context,
        ClassNode classNode)
          throws CompilationFailedException

Specified by:: call in class CompilationUnit.PrimaryClassNodeOperation
Throws:: CompilationFailedException

Class SecureASTCustomizer