正如我所观察到的（并从 Veracode 的消息中理解），应该执行以下操作：
- 要删除的换行符，以便不能伪造日志（通过生成可以模仿日志条目的输入）
- 要转义/编码某些字符以减轻对日志查看工具的攻击
这可以通过使用encodeForHtml()ESAPI 库中的编码方法来实现。但是，该库需要一些额外的配置（ESAPI.properties），如果您只想转义记录的值，这是多余的。为了克服这个问题，我提取（并稍微修改）了转义代码。这是代码：
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
public class HtmlEncoder {
private static final char REPLACEMENT_CHAR = '\ufffd';
private static final String REPLACEMENT_HEX = "fffd";
private static Map<Character,String> characterToEntityMap; // statically initialized
/**
* Initialize an array to mark which characters are to be encoded. Store the hex
* string for that character to save time later. If the character shouldn't be
* encoded, then store null.
*/
private static final String[] encodedCharsCache = new String[256];
public String encodeForHTML(String input) {
return encode(input);
}
// note: bases encodeForHTML() from ESAPI. Unfortunately ESAPI requires configuration in properties which
// is a pain if you just need to encode
private String encode(String input) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < input.length(); i++) {
char c = input.charAt(i);
sb.append(encodeCharacter(c));
}
return sb.toString();
}
private static String toHex(char c) {
return Integer.toHexString(c);
}
private static String getHexForNonAlphanumeric(char c) {
// note: we cache only up to 256 characters (ASCII)
return c < 0xFF ? encodedCharsCache[c] : toHex(c);
}
private String encodeCharacter( Character c ) {
// check for immune characters
if ( c == ',' || c == '.' || c == '-' || c == '_' || c == ' ') {
return ""+c;
}
// check for alphanumeric characters
String hex = getHexForNonAlphanumeric(c);
if ( hex == null ) { // means we should not encode the character
return ""+c;
}
// check for illegal characters
if ( ( c <= 0x1f && c != '\t' && c != '\n' && c != '\r' ) || ( c >= 0x7f && c <= 0x9f ) )
{
hex = REPLACEMENT_HEX; // Let's entity encode this instead of returning it
c = REPLACEMENT_CHAR;
}
// check if there's a defined entity
String entityName = (String) characterToEntityMap.get(c);
if (entityName != null) {
return "&" + entityName + ";";
}
// return hex representation of entity
return "&#x" + hex + ";";
}
static {
for ( char c = 0; c < 0xFF; c++ ) {
if ( c >= 0x30 && c <= 0x39 || c >= 0x41 && c <= 0x5A || c >= 0x61 && c <= 0x7A ) {
encodedCharsCache[c] = null;
} else {
encodedCharsCache[c] = toHex(c).intern();
}
}
Map<Character, String> map = new HashMap<Character,String>(252);
map.put((char)34, "quot"); /* quotation mark */
map.put((char)38, "amp"); /* ampersand */
map.put((char)60, "lt"); /* less-than sign */
map.put((char)62, "gt"); /* greater-than sign */
map.put((char)160, "nbsp"); /* no-break space */
map.put((char)161, "iexcl"); /* inverted exclamation mark */
map.put((char)162, "cent"); /* cent sign */
map.put((char)163, "pound"); /* pound sign */
map.put((char)164, "curren"); /* currency sign */
map.put((char)165, "yen"); /* yen sign */
map.put((char)166, "brvbar"); /* broken bar */
map.put((char)167, "sect"); /* section sign */
map.put((char)168, "uml"); /* diaeresis */
map.put((char)169, "copy"); /* copyright sign */
map.put((char)170, "ordf"); /* feminine ordinal indicator */
map.put((char)171, "laquo"); /* left-pointing double angle quotation mark */
map.put((char)172, "not"); /* not sign */
map.put((char)173, "shy"); /* soft hyphen */
map.put((char)174, "reg"); /* registered sign */
map.put((char)175, "macr"); /* macron */
map.put((char)176, "deg"); /* degree sign */
map.put((char)177, "plusmn"); /* plus-minus sign */
map.put((char)178, "sup2"); /* superscript two */
map.put((char)179, "sup3"); /* superscript three */
map.put((char)180, "acute"); /* acute accent */
map.put((char)181, "micro"); /* micro sign */
map.put((char)182, "para"); /* pilcrow sign */
map.put((char)183, "middot"); /* middle dot */
map.put((char)184, "cedil"); /* cedilla */
map.put((char)185, "sup1"); /* superscript one */
map.put((char)186, "ordm"); /* masculine ordinal indicator */
map.put((char)187, "raquo"); /* right-pointing double angle quotation mark */
map.put((char)188, "frac14"); /* vulgar fraction one quarter */
map.put((char)189, "frac12"); /* vulgar fraction one half */
map.put((char)190, "frac34"); /* vulgar fraction three quarters */
map.put((char)191, "iquest"); /* inverted question mark */
map.put((char)192, "Agrave"); /* Latin capital letter a with grave */
map.put((char)193, "Aacute"); /* Latin capital letter a with acute */
map.put((char)194, "Acirc"); /* Latin capital letter a with circumflex */
map.put((char)195, "Atilde"); /* Latin capital letter a with tilde */
map.put((char)196, "Auml"); /* Latin capital letter a with diaeresis */
map.put((char)197, "Aring"); /* Latin capital letter a with ring above */
map.put((char)198, "AElig"); /* Latin capital letter ae */
map.put((char)199, "Ccedil"); /* Latin capital letter c with cedilla */
map.put((char)200, "Egrave"); /* Latin capital letter e with grave */
map.put((char)201, "Eacute"); /* Latin capital letter e with acute */
map.put((char)202, "Ecirc"); /* Latin capital letter e with circumflex */
map.put((char)203, "Euml"); /* Latin capital letter e with diaeresis */
map.put((char)204, "Igrave"); /* Latin capital letter i with grave */
map.put((char)205, "Iacute"); /* Latin capital letter i with acute */
map.put((char)206, "Icirc"); /* Latin capital letter i with circumflex */
map.put((char)207, "Iuml"); /* Latin capital letter i with diaeresis */
map.put((char)208, "ETH"); /* Latin capital letter eth */
map.put((char)209, "Ntilde"); /* Latin capital letter n with tilde */
map.put((char)210, "Ograve"); /* Latin capital letter o with grave */
map.put((char)211, "Oacute"); /* Latin capital letter o with acute */
map.put((char)212, "Ocirc"); /* Latin capital letter o with circumflex */
map.put((char)213, "Otilde"); /* Latin capital letter o with tilde */
map.put((char)214, "Ouml"); /* Latin capital letter o with diaeresis */
map.put((char)215, "times"); /* multiplication sign */
map.put((char)216, "Oslash"); /* Latin capital letter o with stroke */
map.put((char)217, "Ugrave"); /* Latin capital letter u with grave */
map.put((char)218, "Uacute"); /* Latin capital letter u with acute */
map.put((char)219, "Ucirc"); /* Latin capital letter u with circumflex */
map.put((char)220, "Uuml"); /* Latin capital letter u with diaeresis */
map.put((char)221, "Yacute"); /* Latin capital letter y with acute */
map.put((char)222, "THORN"); /* Latin capital letter thorn */
map.put((char)223, "szlig"); /* Latin small letter sharp sXCOMMAX German Eszett */
map.put((char)224, "agrave"); /* Latin small letter a with grave */
map.put((char)225, "aacute"); /* Latin small letter a with acute */
map.put((char)226, "acirc"); /* Latin small letter a with circumflex */
map.put((char)227, "atilde"); /* Latin small letter a with tilde */
map.put((char)228, "auml"); /* Latin small letter a with diaeresis */
map.put((char)229, "aring"); /* Latin small letter a with ring above */
map.put((char)230, "aelig"); /* Latin lowercase ligature ae */
map.put((char)231, "ccedil"); /* Latin small letter c with cedilla */
map.put((char)232, "egrave"); /* Latin small letter e with grave */
map.put((char)233, "eacute"); /* Latin small letter e with acute */
map.put((char)234, "ecirc"); /* Latin small letter e with circumflex */
map.put((char)235, "euml"); /* Latin small letter e with diaeresis */
map.put((char)236, "igrave"); /* Latin small letter i with grave */
map.put((char)237, "iacute"); /* Latin small letter i with acute */
map.put((char)238, "icirc"); /* Latin small letter i with circumflex */
map.put((char)239, "iuml"); /* Latin small letter i with diaeresis */
map.put((char)240, "eth"); /* Latin small letter eth */
map.put((char)241, "ntilde"); /* Latin small letter n with tilde */
map.put((char)242, "ograve"); /* Latin small letter o with grave */
map.put((char)243, "oacute"); /* Latin small letter o with acute */
map.put((char)244, "ocirc"); /* Latin small letter o with circumflex */
map.put((char)245, "otilde"); /* Latin small letter o with tilde */
map.put((char)246, "ouml"); /* Latin small letter o with diaeresis */
map.put((char)247, "divide"); /* division sign */
map.put((char)248, "oslash"); /* Latin small letter o with stroke */
map.put((char)249, "ugrave"); /* Latin small letter u with grave */
map.put((char)250, "uacute"); /* Latin small letter u with acute */
map.put((char)251, "ucirc"); /* Latin small letter u with circumflex */
map.put((char)252, "uuml"); /* Latin small letter u with diaeresis */
map.put((char)253, "yacute"); /* Latin small letter y with acute */
map.put((char)254, "thorn"); /* Latin small letter thorn */
map.put((char)255, "yuml"); /* Latin small letter y with diaeresis */
map.put((char)338, "OElig"); /* Latin capital ligature oe */
map.put((char)339, "oelig"); /* Latin small ligature oe */
map.put((char)352, "Scaron"); /* Latin capital letter s with caron */
map.put((char)353, "scaron"); /* Latin small letter s with caron */
map.put((char)376, "Yuml"); /* Latin capital letter y with diaeresis */
map.put((char)402, "fnof"); /* Latin small letter f with hook */
map.put((char)710, "circ"); /* modifier letter circumflex accent */
map.put((char)732, "tilde"); /* small tilde */
map.put((char)913, "Alpha"); /* Greek capital letter alpha */
map.put((char)914, "Beta"); /* Greek capital letter beta */
map.put((char)915, "Gamma"); /* Greek capital letter gamma */
map.put((char)916, "Delta"); /* Greek capital letter delta */
map.put((char)917, "Epsilon"); /* Greek capital letter epsilon */
map.put((char)918, "Zeta"); /* Greek capital letter zeta */
map.put((char)919, "Eta"); /* Greek capital letter eta */
map.put((char)920, "Theta"); /* Greek capital letter theta */
map.put((char)921, "Iota"); /* Greek capital letter iota */
map.put((char)922, "Kappa"); /* Greek capital letter kappa */
map.put((char)923, "Lambda"); /* Greek capital letter lambda */
map.put((char)924, "Mu"); /* Greek capital letter mu */
map.put((char)925, "Nu"); /* Greek capital letter nu */
map.put((char)926, "Xi"); /* Greek capital letter xi */
map.put((char)927, "Omicron"); /* Greek capital letter omicron */
map.put((char)928, "Pi"); /* Greek capital letter pi */
map.put((char)929, "Rho"); /* Greek capital letter rho */
map.put((char)931, "Sigma"); /* Greek capital letter sigma */
map.put((char)932, "Tau"); /* Greek capital letter tau */
map.put((char)933, "Upsilon"); /* Greek capital letter upsilon */
map.put((char)934, "Phi"); /* Greek capital letter phi */
map.put((char)935, "Chi"); /* Greek capital letter chi */
map.put((char)936, "Psi"); /* Greek capital letter psi */
map.put((char)937, "Omega"); /* Greek capital letter omega */
map.put((char)945, "alpha"); /* Greek small letter alpha */
map.put((char)946, "beta"); /* Greek small letter beta */
map.put((char)947, "gamma"); /* Greek small letter gamma */
map.put((char)948, "delta"); /* Greek small letter delta */
map.put((char)949, "epsilon"); /* Greek small letter epsilon */
map.put((char)950, "zeta"); /* Greek small letter zeta */
map.put((char)951, "eta"); /* Greek small letter eta */
map.put((char)952, "theta"); /* Greek small letter theta */
map.put((char)953, "iota"); /* Greek small letter iota */
map.put((char)954, "kappa"); /* Greek small letter kappa */
map.put((char)955, "lambda"); /* Greek small letter lambda */
map.put((char)956, "mu"); /* Greek small letter mu */
map.put((char)957, "nu"); /* Greek small letter nu */
map.put((char)958, "xi"); /* Greek small letter xi */
map.put((char)959, "omicron"); /* Greek small letter omicron */
map.put((char)960, "pi"); /* Greek small letter pi */
map.put((char)961, "rho"); /* Greek small letter rho */
map.put((char)962, "sigmaf"); /* Greek small letter final sigma */
map.put((char)963, "sigma"); /* Greek small letter sigma */
map.put((char)964, "tau"); /* Greek small letter tau */
map.put((char)965, "upsilon"); /* Greek small letter upsilon */
map.put((char)966, "phi"); /* Greek small letter phi */
map.put((char)967, "chi"); /* Greek small letter chi */
map.put((char)968, "psi"); /* Greek small letter psi */
map.put((char)969, "omega"); /* Greek small letter omega */
map.put((char)977, "thetasym"); /* Greek theta symbol */
map.put((char)978, "upsih"); /* Greek upsilon with hook symbol */
map.put((char)982, "piv"); /* Greek pi symbol */
map.put((char)8194, "ensp"); /* en space */
map.put((char)8195, "emsp"); /* em space */
map.put((char)8201, "thinsp"); /* thin space */
map.put((char)8204, "zwnj"); /* zero width non-joiner */
map.put((char)8205, "zwj"); /* zero width joiner */
map.put((char)8206, "lrm"); /* left-to-right mark */
map.put((char)8207, "rlm"); /* right-to-left mark */
map.put((char)8211, "ndash"); /* en dash */
map.put((char)8212, "mdash"); /* em dash */
map.put((char)8216, "lsquo"); /* left single quotation mark */
map.put((char)8217, "rsquo"); /* right single quotation mark */
map.put((char)8218, "sbquo"); /* single low-9 quotation mark */
map.put((char)8220, "ldquo"); /* left double quotation mark */
map.put((char)8221, "rdquo"); /* right double quotation mark */
map.put((char)8222, "bdquo"); /* double low-9 quotation mark */
map.put((char)8224, "dagger"); /* dagger */
map.put((char)8225, "Dagger"); /* double dagger */
map.put((char)8226, "bull"); /* bullet */
map.put((char)8230, "hellip"); /* horizontal ellipsis */
map.put((char)8240, "permil"); /* per mille sign */
map.put((char)8242, "prime"); /* prime */
map.put((char)8243, "Prime"); /* double prime */
map.put((char)8249, "lsaquo"); /* single left-pointing angle quotation mark */
map.put((char)8250, "rsaquo"); /* single right-pointing angle quotation mark */
map.put((char)8254, "oline"); /* overline */
map.put((char)8260, "frasl"); /* fraction slash */
map.put((char)8364, "euro"); /* euro sign */
map.put((char)8465, "image"); /* black-letter capital i */
map.put((char)8472, "weierp"); /* script capital pXCOMMAX Weierstrass p */
map.put((char)8476, "real"); /* black-letter capital r */
map.put((char)8482, "trade"); /* trademark sign */
map.put((char)8501, "alefsym"); /* alef symbol */
map.put((char)8592, "larr"); /* leftwards arrow */
map.put((char)8593, "uarr"); /* upwards arrow */
map.put((char)8594, "rarr"); /* rightwards arrow */
map.put((char)8595, "darr"); /* downwards arrow */
map.put((char)8596, "harr"); /* left right arrow */
map.put((char)8629, "crarr"); /* downwards arrow with corner leftwards */
map.put((char)8656, "lArr"); /* leftwards double arrow */
map.put((char)8657, "uArr"); /* upwards double arrow */
map.put((char)8658, "rArr"); /* rightwards double arrow */
map.put((char)8659, "dArr"); /* downwards double arrow */
map.put((char)8660, "hArr"); /* left right double arrow */
map.put((char)8704, "forall"); /* for all */
map.put((char)8706, "part"); /* partial differential */
map.put((char)8707, "exist"); /* there exists */
map.put((char)8709, "empty"); /* empty set */
map.put((char)8711, "nabla"); /* nabla */
map.put((char)8712, "isin"); /* element of */
map.put((char)8713, "notin"); /* not an element of */
map.put((char)8715, "ni"); /* contains as member */
map.put((char)8719, "prod"); /* n-ary product */
map.put((char)8721, "sum"); /* n-ary summation */
map.put((char)8722, "minus"); /* minus sign */
map.put((char)8727, "lowast"); /* asterisk operator */
map.put((char)8730, "radic"); /* square root */
map.put((char)8733, "prop"); /* proportional to */
map.put((char)8734, "infin"); /* infinity */
map.put((char)8736, "ang"); /* angle */
map.put((char)8743, "and"); /* logical and */
map.put((char)8744, "or"); /* logical or */
map.put((char)8745, "cap"); /* intersection */
map.put((char)8746, "cup"); /* union */
map.put((char)8747, "int"); /* integral */
map.put((char)8756, "there4"); /* therefore */
map.put((char)8764, "sim"); /* tilde operator */
map.put((char)8773, "cong"); /* congruent to */
map.put((char)8776, "asymp"); /* almost equal to */
map.put((char)8800, "ne"); /* not equal to */
map.put((char)8801, "equiv"); /* identical toXCOMMAX equivalent to */
map.put((char)8804, "le"); /* less-than or equal to */
map.put((char)8805, "ge"); /* greater-than or equal to */
map.put((char)8834, "sub"); /* subset of */
map.put((char)8835, "sup"); /* superset of */
map.put((char)8836, "nsub"); /* not a subset of */
map.put((char)8838, "sube"); /* subset of or equal to */
map.put((char)8839, "supe"); /* superset of or equal to */
map.put((char)8853, "oplus"); /* circled plus */
map.put((char)8855, "otimes"); /* circled times */
map.put((char)8869, "perp"); /* up tack */
map.put((char)8901, "sdot"); /* dot operator */
map.put((char)8968, "lceil"); /* left ceiling */
map.put((char)8969, "rceil"); /* right ceiling */
map.put((char)8970, "lfloor"); /* left floor */
map.put((char)8971, "rfloor"); /* right floor */
map.put((char)9001, "lang"); /* left-pointing angle bracket */
map.put((char)9002, "rang"); /* right-pointing angle bracket */
map.put((char)9674, "loz"); /* lozenge */
map.put((char)9824, "spades"); /* black spade suit */
map.put((char)9827, "clubs"); /* black club suit */
map.put((char)9829, "hearts"); /* black heart suit */
map.put((char)9830, "diams"); /* black diamond suit */
characterToEntityMap = Collections.unmodifiableMap(map);
}
}
现在有了该功能，您可以通过以下方式记录您的条目：
// below can be static (to be shared), or the method HtmlEncoder#encodeForHtml can be made static for easier usage.. but just to illustrate
private HtmlEncoder htmlEncoder = new HtmlEncoder();
logger.info("I wanted to log param: [{}]", htmlEncoder.encodeForHTML(someVariable));