Package org.codehaus.groovy.control.customizers

Class SecureASTCustomizer

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 security customization 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 recommended 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

  • Constructor Details

    • SecureASTCustomizer

      public SecureASTCustomizer()

  • Method Details

    • 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