/*
* Copyright 2014 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.handler.ssl;
import io.netty.util.internal.PlatformDependent;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ConcurrentMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Converts a Java cipher suite string to an OpenSSL cipher suite string and vice versa.
*
* @see <a href="http://en.wikipedia.org/wiki/Cipher_suite">Wikipedia page about cipher suite</a>
*/
final class CipherSuiteConverter {
private static final InternalLogger logger = InternalLoggerFactory.getInstance(CipherSuiteConverter.class);
/**
* A_B_WITH_C_D, where:
*
* A - TLS or SSL (protocol)
* B - handshake algorithm (key exchange and authentication algorithms to be precise)
* C - bulk cipher
* D - HMAC algorithm
*
* This regular expression assumees that:
*
* 1) A is always TLS or SSL, and
* 2) D is always a single word.
*/
private static final Pattern JAVA_CIPHERSUITE_PATTERN =
Pattern.compile("^(?:TLS|SSL)_((?:(?!_WITH_).)+)_WITH_(.*)_(.*)$");
/**
* A-B-C, where:
*
* A - handshake algorithm (key exchange and authentication algorithms to be precise)
* B - bulk cipher
* C - HMAC algorithm
*
* This regular expression assumes that:
*
* 1) A has some deterministic pattern as shown below, and
* 2) C is always a single word
*/
private static final Pattern OPENSSL_CIPHERSUITE_PATTERN =
// Be very careful not to break the indentation while editing.
Pattern.compile(
"^(?:(" + // BEGIN handshake algorithm
"(?:(?:EXP-)?" +
"(?:" +
"(?:DHE|EDH|ECDH|ECDHE|SRP)-(?:DSS|RSA|ECDSA)|" +
"(?:ADH|AECDH|KRB5|PSK|SRP)" +
')' +
")|" +
"EXP" +
")-)?" + // END handshake algorithm
"(.*)-(.*)$");
private static final Pattern JAVA_AES_CBC_PATTERN = Pattern.compile("^(AES)_([0-9]+)_CBC$");
private static final Pattern JAVA_AES_PATTERN = Pattern.compile("^(AES)_([0-9]+)_(.*)$");
private static final Pattern OPENSSL_AES_CBC_PATTERN = Pattern.compile("^(AES)([0-9]+)$");
private static final Pattern OPENSSL_AES_PATTERN = Pattern.compile("^(AES)([0-9]+)-(.*)$");
/**
* Java-to-OpenSSL cipher suite conversion map
* Note that the Java cipher suite has the protocol prefix (TLS_, SSL_)
*/
private static final ConcurrentMap<String, String> j2o = PlatformDependent.newConcurrentHashMap();
/**
* OpenSSL-to-Java cipher suite conversion map.
* Note that one OpenSSL cipher suite can be converted to more than one Java cipher suites because
* a Java cipher suite has the protocol name prefix (TLS_, SSL_)
*/
private static final ConcurrentMap<String, Map<String, String>> o2j = PlatformDependent.newConcurrentHashMap();
/**
* Clears the cache for testing purpose.
*/
static void clearCache() {
j2o.clear();
o2j.clear();
}
/**
* Tests if the specified key-value pair has been cached in Java-to-OpenSSL cache.
*/
static boolean isJ2OCached(String key, String value) {
return value.equals(j2o.get(key));
}
/**
* Tests if the specified key-value pair has been cached in OpenSSL-to-Java cache.
*/
static boolean isO2JCached(String key, String protocol, String value) {
Map<String, String> p2j = o2j.get(key);
if (p2j == null) {
return false;
} else {
return value.equals(p2j.get(protocol));
}
}
/**
* Converts the specified Java cipher suites to the colon-separated OpenSSL cipher suite specification.
*/
static String toOpenSsl(Iterable<String> javaCipherSuites) {
final StringBuilder buf = new StringBuilder();
for (String c: javaCipherSuites) {
if (c == null) {
break;
}
String converted = toOpenSsl(c);
if (converted != null) {
c = converted;
}
buf.append(c);
buf.append(':');
}
if (buf.length() > 0) {
buf.setLength(buf.length() - 1);
return buf.toString();
} else {
return "";
}
}
/**
* Converts the specified Java cipher suite to its corresponding OpenSSL cipher suite name.
*
* @return {@code null} if the conversion has failed
*/
static String toOpenSsl(String javaCipherSuite) {
String converted = j2o.get(javaCipherSuite);
if (converted != null) {
return converted;
} else {
return cacheFromJava(javaCipherSuite);
}
}
private static String cacheFromJava(String javaCipherSuite) {
String openSslCipherSuite = toOpenSslUncached(javaCipherSuite);
if (openSslCipherSuite == null) {
return null;
}
// Cache the mapping.
j2o.putIfAbsent(javaCipherSuite, openSslCipherSuite);
// Cache the reverse mapping after stripping the protocol prefix (TLS_ or SSL_)
final String javaCipherSuiteSuffix = javaCipherSuite.substring(4);
Map<String, String> p2j = new HashMap<String, String>(4);
p2j.put("", javaCipherSuiteSuffix);
p2j.put("SSL", "SSL_" + javaCipherSuiteSuffix);
p2j.put("TLS", "TLS_" + javaCipherSuiteSuffix);
o2j.put(openSslCipherSuite, p2j);
logger.debug("Cipher suite mapping: {} => {}", javaCipherSuite, openSslCipherSuite);
return openSslCipherSuite;
}
static String toOpenSslUncached(String javaCipherSuite) {
Matcher m = JAVA_CIPHERSUITE_PATTERN.matcher(javaCipherSuite);
if (!m.matches()) {
return null;
}
String handshakeAlgo = toOpenSslHandshakeAlgo(m.group(1));
String bulkCipher = toOpenSslBulkCipher(m.group(2));
String hmacAlgo = toOpenSslHmacAlgo(m.group(3));
if (handshakeAlgo.length() == 0) {
return bulkCipher + '-' + hmacAlgo;
} else {
return handshakeAlgo + '-' + bulkCipher + '-' + hmacAlgo;
}
}
private static String toOpenSslHandshakeAlgo(String handshakeAlgo) {
final boolean export = handshakeAlgo.endsWith("_EXPORT");
if (export) {
handshakeAlgo = handshakeAlgo.substring(0, handshakeAlgo.length() - 7);
}
if ("RSA".equals(handshakeAlgo)) {
handshakeAlgo = "";
} else if (handshakeAlgo.endsWith("_anon")) {
handshakeAlgo = 'A' + handshakeAlgo.substring(0, handshakeAlgo.length() - 5);
}
if (export) {
if (handshakeAlgo.length() == 0) {
handshakeAlgo = "EXP";
} else {
handshakeAlgo = "EXP-" + handshakeAlgo;
}
}
return handshakeAlgo.replace('_', '-');
}
private static String toOpenSslBulkCipher(String bulkCipher) {
if (bulkCipher.startsWith("AES_")) {
Matcher m = JAVA_AES_CBC_PATTERN.matcher(bulkCipher);
if (m.matches()) {
return m.replaceFirst("$1$2");
}
m = JAVA_AES_PATTERN.matcher(bulkCipher);
if (m.matches()) {
return m.replaceFirst("$1$2-$3");
}
}
if ("3DES_EDE_CBC".equals(bulkCipher)) {
return "DES-CBC3";
}
if ("RC4_128".equals(bulkCipher) || "RC4_40".equals(bulkCipher)) {
return "RC4";
}
if ("DES40_CBC".equals(bulkCipher) || "DES_CBC_40".equals(bulkCipher)) {
return "DES-CBC";
}
if ("RC2_CBC_40".equals(bulkCipher)) {
return "RC2-CBC";
}
return bulkCipher.replace('_', '-');
}
private static String toOpenSslHmacAlgo(String hmacAlgo) {
// Java and OpenSSL use the same algorithm names for:
//
// * SHA
// * SHA256
// * MD5
//
return hmacAlgo;
}
/**
* Convert from OpenSSL cipher suite name convention to java cipher suite name convention.
* @param openSslCipherSuite An OpenSSL cipher suite name.
* @param protocol The cryptographic protocol (i.e. SSL, TLS, ...).
* @return The translated cipher suite name according to java conventions. This will not be {@code null}.
*/
static String toJava(String openSslCipherSuite, String protocol) {
Map<String, String> p2j = o2j.get(openSslCipherSuite);
if (p2j == null) {
p2j = cacheFromOpenSsl(openSslCipherSuite);
}
String javaCipherSuite = p2j.get(protocol);
if (javaCipherSuite == null) {
javaCipherSuite = protocol + '_' + p2j.get("");
}
return javaCipherSuite;
}
private static Map<String, String> cacheFromOpenSsl(String openSslCipherSuite) {
String javaCipherSuiteSuffix = toJavaUncached(openSslCipherSuite);
if (javaCipherSuiteSuffix == null) {
return null;
}
final String javaCipherSuiteSsl = "SSL_" + javaCipherSuiteSuffix;
final String javaCipherSuiteTls = "TLS_" + javaCipherSuiteSuffix;
// Cache the mapping.
final Map<String, String> p2j = new HashMap<String, String>(4);
p2j.put("", javaCipherSuiteSuffix);
p2j.put("SSL", javaCipherSuiteSsl);
p2j.put("TLS", javaCipherSuiteTls);
o2j.putIfAbsent(openSslCipherSuite, p2j);
// Cache the reverse mapping after adding the protocol prefix (TLS_ or SSL_)
j2o.putIfAbsent(javaCipherSuiteTls, openSslCipherSuite);
j2o.putIfAbsent(javaCipherSuiteSsl, openSslCipherSuite);
logger.debug("Cipher suite mapping: {} => {}", javaCipherSuiteTls, openSslCipherSuite);
logger.debug("Cipher suite mapping: {} => {}", javaCipherSuiteSsl, openSslCipherSuite);
return p2j;
}
static String toJavaUncached(String openSslCipherSuite) {
Matcher m = OPENSSL_CIPHERSUITE_PATTERN.matcher(openSslCipherSuite);
if (!m.matches()) {
return null;
}
String handshakeAlgo = m.group(1);
final boolean export;
if (handshakeAlgo == null) {
handshakeAlgo = "";
export = false;
} else if (handshakeAlgo.startsWith("EXP-")) {
handshakeAlgo = handshakeAlgo.substring(4);
export = true;
} else if ("EXP".equals(handshakeAlgo)) {
handshakeAlgo = "";
export = true;
} else {
export = false;
}
handshakeAlgo = toJavaHandshakeAlgo(handshakeAlgo, export);
String bulkCipher = toJavaBulkCipher(m.group(2), export);
String hmacAlgo = toJavaHmacAlgo(m.group(3));
return handshakeAlgo + "_WITH_" + bulkCipher + '_' + hmacAlgo;
}
private static String toJavaHandshakeAlgo(String handshakeAlgo, boolean export) {
if (handshakeAlgo.length() == 0) {
handshakeAlgo = "RSA";
} else if ("ADH".equals(handshakeAlgo)) {
handshakeAlgo = "DH_anon";
} else if ("AECDH".equals(handshakeAlgo)) {
handshakeAlgo = "ECDH_anon";
}
handshakeAlgo = handshakeAlgo.replace('-', '_');
if (export) {
return handshakeAlgo + "_EXPORT";
} else {
return handshakeAlgo;
}
}
private static String toJavaBulkCipher(String bulkCipher, boolean export) {
if (bulkCipher.startsWith("AES")) {
Matcher m = OPENSSL_AES_CBC_PATTERN.matcher(bulkCipher);
if (m.matches()) {
return m.replaceFirst("$1_$2_CBC");
}
m = OPENSSL_AES_PATTERN.matcher(bulkCipher);
if (m.matches()) {
return m.replaceFirst("$1_$2_$3");
}
}
if ("DES-CBC3".equals(bulkCipher)) {
return "3DES_EDE_CBC";
}
if ("RC4".equals(bulkCipher)) {
if (export) {
return "RC4_40";
} else {
return "RC4_128";
}
}
if ("DES-CBC".equals(bulkCipher)) {
if (export) {
return "DES_CBC_40";
} else {
return "DES_CBC";
}
}
if ("RC2-CBC".equals(bulkCipher)) {
if (export) {
return "RC2_CBC_40";
} else {
return "RC2_CBC";
}
}
return bulkCipher.replace('-', '_');
}
private static String toJavaHmacAlgo(String hmacAlgo) {
// Java and OpenSSL use the same algorithm names for:
//
// * SHA
// * SHA256
// * MD5
//
return hmacAlgo;
}
private CipherSuiteConverter() { }
}