| /* RSASignatureFactory.java -- A Factory class to instantiate RSA Signatures |
| Copyright (C) 2006 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.java.security.sig.rsa; |
| |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.Set; |
| |
| import gnu.java.security.Registry; |
| import gnu.java.security.hash.HashFactory; |
| import gnu.java.security.hash.IMessageDigest; |
| import gnu.java.security.sig.ISignature; |
| |
| /** |
| * A Factory class to instantiate RSA Signature classes. |
| */ |
| public class RSASignatureFactory |
| { |
| private static Set names; |
| |
| /** |
| * Private constructor to enforce usage through Factory (class) methods. |
| */ |
| private RSASignatureFactory() |
| { |
| super(); |
| } |
| |
| /** |
| * Returns a new instance of an RSA Signature given its name. The name of an |
| * RSA Signature always starts with <code>rsa-</code>, followed by either |
| * <code>pss</code> or <code>pkcs1_v1.5</code>. An optional message digest |
| * name, to be used with the RSA signature may be specified by appending the |
| * hyphen chanaracter <code>-</code> followed by the canonical message digest |
| * algorithm name. When no message digest algorithm name is given, SHA-160 is |
| * used. |
| * |
| * @param name the composite RSA signature name. |
| * @return a new instance of an RSA Signature algorithm implementation. |
| * Returns <code>null</code> if the given name does not correspond to any |
| * supported RSA Signature encoding and message digest combination. |
| */ |
| public static final ISignature getInstance(String name) |
| { |
| if (name == null) |
| return null; |
| |
| name = name.trim(); |
| if (name.length() == 0) |
| return null; |
| |
| name = name.toLowerCase(); |
| if (! name.startsWith(Registry.RSA_SIG_PREFIX)) |
| return null; |
| |
| name = name.substring(Registry.RSA_SIG_PREFIX.length()).trim(); |
| if (name.startsWith(Registry.RSA_PSS_ENCODING)) |
| return getPSSSignature(name); |
| else if (name.startsWith(Registry.RSA_PKCS1_V1_5_ENCODING)) |
| return getPKCS1Signature(name); |
| else |
| return null; |
| } |
| |
| /** |
| * Returns a {@link Set} of names of <i>RSA</i> signatures supported by this |
| * <i>Factory</i>. |
| * |
| * @return a {@link Set} of RSA Signature algorithm names (Strings). |
| */ |
| public static synchronized final Set getNames() |
| { |
| if (names == null) |
| { |
| Set hashNames = HashFactory.getNames(); |
| HashSet hs = new HashSet(); |
| for (Iterator it = hashNames.iterator(); it.hasNext();) |
| { |
| String mdName = (String) it.next(); |
| hs.add(Registry.RSA_PSS_SIG + "-" + mdName); |
| } |
| |
| hs.add(Registry.RSA_PKCS1_V1_5_SIG + "-" + Registry.MD2_HASH); |
| hs.add(Registry.RSA_PKCS1_V1_5_SIG + "-" + Registry.MD5_HASH); |
| hs.add(Registry.RSA_PKCS1_V1_5_SIG + "-" + Registry.SHA160_HASH); |
| hs.add(Registry.RSA_PKCS1_V1_5_SIG + "-" + Registry.SHA256_HASH); |
| hs.add(Registry.RSA_PKCS1_V1_5_SIG + "-" + Registry.SHA384_HASH); |
| hs.add(Registry.RSA_PKCS1_V1_5_SIG + "-" + Registry.SHA512_HASH); |
| |
| names = Collections.unmodifiableSet(hs); |
| } |
| |
| return names; |
| } |
| |
| private static final ISignature getPSSSignature(String name) |
| { |
| name = name.substring(Registry.RSA_PSS_ENCODING.length()).trim(); |
| // remove the hyphen if found at the beginning |
| if (name.startsWith("-")) |
| name = name.substring(1).trim(); |
| |
| IMessageDigest md; |
| if (name.length() == 0) |
| md = HashFactory.getInstance(Registry.SHA160_HASH); |
| else |
| { |
| // check if there is such a hash |
| md = HashFactory.getInstance(name); |
| if (md == null) |
| return null; |
| } |
| |
| ISignature result = new RSAPSSSignature(md, 0); |
| return result; |
| } |
| |
| private static final ISignature getPKCS1Signature(String name) |
| { |
| name = name.substring(Registry.RSA_PKCS1_V1_5_ENCODING.length()).trim(); |
| // remove the hyphen if found at the beginning |
| if (name.startsWith("-")) |
| name = name.substring(1).trim(); |
| |
| IMessageDigest md; |
| if (name.length() == 0) |
| md = HashFactory.getInstance(Registry.SHA160_HASH); |
| else |
| { |
| // check if there is such a hash |
| md = HashFactory.getInstance(name); |
| if (md == null) |
| return null; |
| } |
| |
| ISignature result = new RSAPKCS1V1_5Signature(md); |
| return result; |
| } |
| } |