Package com.composum.sling.core.util

Class XSS

java.lang.Object

com.composum.sling.core.util.XSS

public class XSS
extends Object

the static access for the Sling XSSAPI / XSSFilter - wraps the Sling XSS services

Field Summary

Fields

Modifier and Type	Field	Description
protected static ServiceHandle<org.apache.sling.xss.XSSAPI>	XSSAPI_HANDLE
protected static ServiceHandle<org.apache.sling.xss.XSSFilter>	XSSFilter_HANDLE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	XSS()

Method Summary

Modifier and Type	Method	Description
static @NotNull org.apache.sling.xss.XSSAPI	api()
static boolean	check(org.apache.sling.xss.ProtectionContext context, String src)	Indicates whether or not a given source string contains XSS policy violations.
static @Nullable String	encodeForCSSString(@Nullable String source)	Encodes a source string for writing to CSS string content.
static @Nullable String	encodeForHTML(@Nullable String source)	Encodes a source string for HTML element content.
static @Nullable String	encodeForHTMLAttr(@Nullable String source)	Encodes a source string for writing to an HTML attribute value.
static @Nullable String	encodeForJSString(@Nullable String source)	Encodes a source string for writing to JavaScript string content.
static @Nullable String	encodeForXML(@Nullable String source)	Encodes a source string for XML element content.
static @Nullable String	encodeForXMLAttr(@Nullable String source)	Encodes a source string for writing to an XML attribute value.
static @NotNull org.apache.sling.xss.XSSFilter	filter()
static String	filter(String src)	Prevents the given source string from containing XSS stuff.
static String[]	filter(String[] src)	Prevents the given source strings from containing XSS stuff.
static String	filter(String contextName, String src)	Protects the given source string from containing XSS stuff.
static String	filter(org.apache.sling.xss.ProtectionContext context, String src)	Protects the given source string from containing XSS stuff.
static @NotNull String	filterHTML(@Nullable String source)	Filters potentially user-contributed HTML to meet the AntiSamy policy rules currently in effect for HTML output (see the XSSFilter service for details).
static @Nullable String	getValidCSSColor(@Nullable String color, @Nullable String defaultColor)	Validate a CSS color value.
static @Nullable String	getValidDimension(@Nullable String dimension, @Nullable String defaultValue)	Validate a string which should contain a dimension, returning a default value if the source is empty, can't be parsed, or contains XSS risks.
static @Nullable Double	getValidDouble(@Nullable String source, double defaultValue)	Validate a string which should contain an double, returning a default value if the source is null, empty, can't be parsed, or contains XSS risks.
static @NotNull String	getValidHref(@Nullable String url)	Sanitizes a URL for writing as an HTML href or src attribute value.
static @Nullable Integer	getValidInteger(@Nullable String integer, int defaultValue)	Validate a string which should contain an integer, returning a default value if the source is null, empty, can't be parsed, or contains XSS risks.
static String	getValidJSON(@Nullable String json, @Nullable String defaultJson)	Validate a JSON string
static @Nullable String	getValidJSToken(@Nullable String token, @Nullable String defaultValue)	Validate a Javascript token.
static @Nullable Long	getValidLong(@Nullable String source, long defaultValue)	Validate a string which should contain a long, returning a default value if the source is null, empty, can't be parsed, or contains XSS risks.
static String	getValidMultiLineComment(@Nullable String comment, @Nullable String defaultComment)	Validate multi-line comment to be used inside a <script>...</script> or <style>...</style> block.
static @Nullable String	getValidStyleToken(@Nullable String token, @Nullable String defaultValue)	Validate a style/CSS token.
static String	getValidXML(@Nullable String xml, @Nullable String defaultXml)	Validate an XML string
static boolean	isValidHref(String url)	Checks if the given URL is valid to be used for the href attribute in a a tag.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

XSSAPI_HANDLE

protected static ServiceHandle<org.apache.sling.xss.XSSAPI> XSSAPI_HANDLE

XSSFilter_HANDLE

protected static ServiceHandle<org.apache.sling.xss.XSSFilter> XSSFilter_HANDLE

Constructor Detail

XSS

protected XSS()

Method Detail

api

@NotNull
public static @NotNull org.apache.sling.xss.XSSAPI api()

filter

@NotNull
public static @NotNull org.apache.sling.xss.XSSFilter filter()

getValidInteger

@Nullable
public static @Nullable Integer getValidInteger(@Nullable
                                                @Nullable String integer,
                                                int defaultValue)

Validate a string which should contain an integer, returning a default value if the source is null, empty, can't be parsed, or contains XSS risks.

Parameters:

integer - the source integer

defaultValue - a default value if the source can't be used, is null or an empty string

Returns:

a sanitized integer

getValidLong

@Nullable
public static @Nullable Long getValidLong(@Nullable
                                          @Nullable String source,
                                          long defaultValue)

Validate a string which should contain a long, returning a default value if the source is null, empty, can't be parsed, or contains XSS risks.

Parameters:

source - the source long

defaultValue - a default value if the source can't be used, is null or an empty string

Returns:

a sanitized integer

getValidDouble

@Nullable
public static @Nullable Double getValidDouble(@Nullable
                                              @Nullable String source,
                                              double defaultValue)

Validate a string which should contain an double, returning a default value if the source is null, empty, can't be parsed, or contains XSS risks.

Parameters:

source - the source double

defaultValue - a default value if the source can't be used, is null or an empty string

Returns:

a sanitized double

getValidDimension

@Nullable
public static @Nullable String getValidDimension(@Nullable
                                                 @Nullable String dimension,
                                                 @Nullable
                                                 @Nullable String defaultValue)

Validate a string which should contain a dimension, returning a default value if the source is empty, can't be parsed, or contains XSS risks. Allows integer dimensions and the keyword "auto".

Parameters:

dimension - the source dimension

defaultValue - a default value if the source can't be used, is null or an empty string

Returns:

a sanitized dimension

getValidHref

@NotNull
public static @NotNull String getValidHref(@Nullable
                                           @Nullable String url)

Sanitizes a URL for writing as an HTML href or src attribute value.

Parameters:

url - the source URL

Returns:

a sanitized URL (possibly empty)

getValidJSToken

@Nullable
public static @Nullable String getValidJSToken(@Nullable
                                               @Nullable String token,
                                               @Nullable
                                               @Nullable String defaultValue)

Validate a Javascript token. The value must be either a single identifier, a literal number, or a literal string.

Parameters:

token - the source token

defaultValue - a default value to use if the source is null, an empty string, or doesn't meet validity constraints.

Returns:

a string containing a single identifier, a literal number, or a literal string token

getValidStyleToken

@Nullable
public static @Nullable String getValidStyleToken(@Nullable
                                                  @Nullable String token,
                                                  @Nullable
                                                  @Nullable String defaultValue)

Validate a style/CSS token. Valid CSS tokens are specified at http://www.w3.org/TR/css3-syntax/

Parameters:

token - the source token

defaultValue - a default value to use if the source is null, an empty string, or doesn't meet validity constraints.

Returns:

a string containing sanitized style token

getValidCSSColor

@Nullable
public static @Nullable String getValidCSSColor(@Nullable
                                                @Nullable String color,
                                                @Nullable
                                                @Nullable String defaultColor)

Validate a CSS color value. Color values as specified at http://www.w3.org/TR/css3-color/#colorunits are safe and definitively allowed. Vulnerable constructs will be disallowed. Currently known vulnerable constructs include url(...), expression(...), and anything with a semicolon.

Parameters:

color - the color value to be used.

defaultColor - a default value to use if the input color value is null, an empty string, doesn't meet validity constraints.

Returns:

a string a css color value.

getValidMultiLineComment

public static String getValidMultiLineComment(@Nullable
                                              @Nullable String comment,
                                              @Nullable
                                              @Nullable String defaultComment)

Validate multi-line comment to be used inside a <script>...</script> or <style>...</style> block. Multi-line comment end block is disallowed.

Parameters:

comment - the comment to be used

defaultComment - a default value to use if the comment is null or not valid.

Returns:

a valid multi-line comment

getValidJSON

public static String getValidJSON(@Nullable
                                  @Nullable String json,
                                  @Nullable
                                  @Nullable String defaultJson)

Validate a JSON string

Parameters:

json - the JSON string to validate

defaultJson - the default value to use if json is null or not valid

Returns:

a valid JSON string

getValidXML

public static String getValidXML(@Nullable
                                 @Nullable String xml,
                                 @Nullable
                                 @Nullable String defaultXml)

Validate an XML string

Parameters:

xml - the XML string to validate

defaultXml - the default value to use if xml is null or not valid

Returns:

a valid XML string

encodeForHTML

@Nullable
public static @Nullable String encodeForHTML(@Nullable
                                             @Nullable String source)

Encodes a source string for HTML element content. DO NOT USE FOR WRITING ATTRIBUTE VALUES!

Parameters:

source - the input to encode

Returns:

an encoded version of the source

encodeForHTMLAttr

@Nullable
public static @Nullable String encodeForHTMLAttr(@Nullable
                                                 @Nullable String source)

Encodes a source string for writing to an HTML attribute value. DO NOT USE FOR ACTIONABLE ATTRIBUTES (href, src, event handlers); YOU MUST USE A VALIDATOR FOR THOSE!

Parameters:

source - the input to encode

Returns:

an encoded version of the source

encodeForXML

@Nullable
public static @Nullable String encodeForXML(@Nullable
                                            @Nullable String source)

Encodes a source string for XML element content. DO NOT USE FOR WRITING ATTRIBUTE VALUES!

Parameters:

source - the input to encode

Returns:

an encoded version of the source

encodeForXMLAttr

@Nullable
public static @Nullable String encodeForXMLAttr(@Nullable
                                                @Nullable String source)

Encodes a source string for writing to an XML attribute value.

Parameters:

source - the input to encode

Returns:

an encoded version of the source

encodeForJSString

@Nullable
public static @Nullable String encodeForJSString(@Nullable
                                                 @Nullable String source)

Encodes a source string for writing to JavaScript string content. DO NOT USE FOR WRITING TO ARBITRARY JAVASCRIPT; YOU MUST USE A VALIDATOR FOR THAT. (Encoding only ensures that the source material cannot break out of its context.)

Parameters:

source - the input to encode

Returns:

an encoded version of the source

encodeForCSSString

@Nullable
public static @Nullable String encodeForCSSString(@Nullable
                                                  @Nullable String source)

Encodes a source string for writing to CSS string content. DO NOT USE FOR WRITING OUT ARBITRARY CSS TOKENS; YOU MUST USE A VALIDATOR FOR THAT! (Encoding only ensures the source string cannot break out of its context.)

Parameters:

source - the input to encode

Returns:

an encoded version of the source

filterHTML

@NotNull
public static @NotNull String filterHTML(@Nullable
                                         @Nullable String source)

Filters potentially user-contributed HTML to meet the AntiSamy policy rules currently in effect for HTML output (see the XSSFilter service for details).

Parameters:

source - a string containing the source HTML

Returns:

a string containing the sanitized HTML which may be an empty string if source is null or empty

check

public static boolean check(org.apache.sling.xss.ProtectionContext context,
                            String src)

Indicates whether or not a given source string contains XSS policy violations.

Parameters:

context - context to use for checking

src - source string

Returns:

true if the source is violation-free

Throws:

NullPointerException - if context is null

filter

public static String filter(String src)

Prevents the given source string from containing XSS stuff.

The default protection context is used for checking.

Parameters:

src - source string

Returns:

string that does not contain XSS stuff

filter

public static String[] filter(String[] src)

Prevents the given source strings from containing XSS stuff.

The default protection context is used for checking.

Parameters:

src - array of source strings

Returns:

array of strings that does not contain XSS stuff

filter

public static String filter(String contextName,
                            String src)

Protects the given source string from containing XSS stuff.

Parameters:

context - context to use for checking

src - source string

Returns:

string that does not contain XSS stuff

Throws:

NullPointerException - if context is null

filter

public static String filter(org.apache.sling.xss.ProtectionContext context,
                            String src)

Protects the given source string from containing XSS stuff.

Parameters:

context - context to use for checking

src - source string

Returns:

string that does not contain XSS stuff

Throws:

NullPointerException - if context is null

isValidHref

public static boolean isValidHref(String url)

Checks if the given URL is valid to be used for the href attribute in a a tag.

The default protection context is used for checking.

Parameters:

url - the URL that should be validated

Returns:

true if the URL is violation-free