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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package com.sun.crypto.provider;
import java.math.BigInteger;
import java.util.*;
import java.io.*;
import sun.security.util.*;
import sun.security.x509.*;
import java.security.AlgorithmParametersSpi;
import java.security.NoSuchAlgorithmException;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.InvalidParameterSpecException;
import java.security.spec.MGF1ParameterSpec;
import javax.crypto.spec.PSource;
import javax.crypto.spec.OAEPParameterSpec;
/**
* This class implements the OAEP parameters used with the RSA
* algorithm in OAEP padding. Here is its ASN.1 definition:
* RSAES-OAEP-params ::= SEQUENCE {
* hashAlgorithm [0] HashAlgorithm DEFAULT sha1,
* maskGenAlgorithm [1] MaskGenAlgorithm DEFAULT mgf1SHA1,
* pSourceAlgorithm [2] PSourceAlgorithm DEFAULT pSpecifiedEmpty
* }
*
* @author Valerie Peng
*
*/
public final class OAEPParameters extends AlgorithmParametersSpi {
private String mdName;
private MGF1ParameterSpec mgfSpec;
private byte[] p;
private static ObjectIdentifier OID_MGF1;
private static ObjectIdentifier OID_PSpecified;
static {
try {
OID_MGF1 = new ObjectIdentifier(new int[] {1,2,840,113549,1,1,8});
} catch (IOException ioe) {
// should not happen
OID_MGF1 = null;
}
try {
OID_PSpecified =
new ObjectIdentifier(new int[] {1,2,840,113549,1,1,9});
} catch (IOException ioe) {
// should not happen
OID_PSpecified = null;
}
}
public OAEPParameters() {
}
protected void engineInit(AlgorithmParameterSpec paramSpec)
throws InvalidParameterSpecException {
if (!(paramSpec instanceof OAEPParameterSpec)) {
throw new InvalidParameterSpecException
("Inappropriate parameter specification");
}
OAEPParameterSpec spec = (OAEPParameterSpec) paramSpec;
mdName = spec.getDigestAlgorithm();
String mgfName = spec.getMGFAlgorithm();
if (!mgfName.equalsIgnoreCase("MGF1")) {
throw new InvalidParameterSpecException("Unsupported mgf " +
mgfName + "; MGF1 only");
}
AlgorithmParameterSpec mgfSpec = spec.getMGFParameters();
if (!(mgfSpec instanceof MGF1ParameterSpec)) {
throw new InvalidParameterSpecException("Inappropriate mgf " +
"parameters; non-null MGF1ParameterSpec only");
}
this.mgfSpec = (MGF1ParameterSpec) mgfSpec;
PSource pSrc = spec.getPSource();
if (pSrc.getAlgorithm().equals("PSpecified")) {
p = ((PSource.PSpecified) pSrc).getValue();
} else {
throw new InvalidParameterSpecException("Unsupported pSource " +
pSrc.getAlgorithm() + "; PSpecified only");
}
}
private static String convertToStandardName(String internalName) {
if (internalName.equals("SHA")) {
return "SHA-1";
} else if (internalName.equals("SHA256")) {
return "SHA-256";
} else if (internalName.equals("SHA384")) {
return "SHA-384";
} else if (internalName.equals("SHA512")) {
return "SHA-512";
} else {
return internalName;
}
}
protected void engineInit(byte[] encoded)
throws IOException {
DerInputStream der = new DerInputStream(encoded);
mdName = "SHA-1";
mgfSpec = MGF1ParameterSpec.SHA1;
p = new byte[0];
DerValue[] datum = der.getSequence(3);
for (int i=0; i<datum.length; i++) {
DerValue data = datum[i];
if (data.isContextSpecific((byte) 0x00)) {
// hash algid
mdName = convertToStandardName(AlgorithmId.parse
(data.data.getDerValue()).getName());
} else if (data.isContextSpecific((byte) 0x01)) {
// mgf algid
AlgorithmId val = AlgorithmId.parse(data.data.getDerValue());
if (!val.getOID().equals((Object) OID_MGF1)) {
throw new IOException("Only MGF1 mgf is supported");
}
AlgorithmId params = AlgorithmId.parse(new DerValue(val.getEncodedParams()));
String mgfDigestName = convertToStandardName(params.getName());
if (mgfDigestName.equals("SHA-1")) {
mgfSpec = MGF1ParameterSpec.SHA1;
} else if (mgfDigestName.equals("SHA-256")) {
mgfSpec = MGF1ParameterSpec.SHA256;
} else if (mgfDigestName.equals("SHA-384")) {
mgfSpec = MGF1ParameterSpec.SHA384;
} else if (mgfDigestName.equals("SHA-512")) {
mgfSpec = MGF1ParameterSpec.SHA512;
} else {
throw new IOException("Unrecognized message digest algorithm");
}
} else if (data.isContextSpecific((byte) 0x02)) {
// pSource algid
AlgorithmId val = AlgorithmId.parse(data.data.getDerValue());
if (!val.getOID().equals((Object) OID_PSpecified)) {
throw new IOException("Wrong OID for pSpecified");
}
DerInputStream dis = new DerInputStream(val.getEncodedParams());
p = dis.getOctetString();
if (dis.available() != 0) {
throw new IOException("Extra data for pSpecified");
}
} else {
throw new IOException("Invalid encoded OAEPParameters");
}
}
}
protected void engineInit(byte[] encoded, String decodingMethod)
throws IOException {
if ((decodingMethod != null) &&
(!decodingMethod.equalsIgnoreCase("ASN.1"))) {
throw new IllegalArgumentException("Only support ASN.1 format");
}
engineInit(encoded);
}
protected AlgorithmParameterSpec engineGetParameterSpec(Class paramSpec)
throws InvalidParameterSpecException {
if (OAEPParameterSpec.class.isAssignableFrom(paramSpec)) {
return new OAEPParameterSpec(mdName, "MGF1", mgfSpec,
new PSource.PSpecified(p));
} else {
throw new InvalidParameterSpecException
("Inappropriate parameter specification");
}
}
protected byte[] engineGetEncoded() throws IOException {
DerOutputStream tmp = new DerOutputStream();
DerOutputStream tmp2, tmp3;
// MD
AlgorithmId mdAlgId;
try {
mdAlgId = AlgorithmId.get(mdName);
} catch (NoSuchAlgorithmException nsae) {
throw new IOException("AlgorithmId " + mdName +
" impl not found");
}
tmp2 = new DerOutputStream();
mdAlgId.derEncode(tmp2);
tmp.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0),
tmp2);
// MGF
tmp2 = new DerOutputStream();
tmp2.putOID(OID_MGF1);
AlgorithmId mgfDigestId;
try {
mgfDigestId = AlgorithmId.get(mgfSpec.getDigestAlgorithm());
} catch (NoSuchAlgorithmException nase) {
throw new IOException("AlgorithmId " +
mgfSpec.getDigestAlgorithm() + " impl not found");
}
mgfDigestId.encode(tmp2);
tmp3 = new DerOutputStream();
tmp3.write(DerValue.tag_Sequence, tmp2);
tmp.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)1),
tmp3);
// PSource
tmp2 = new DerOutputStream();
tmp2.putOID(OID_PSpecified);
tmp2.putOctetString(p);
tmp3 = new DerOutputStream();
tmp3.write(DerValue.tag_Sequence, tmp2);
tmp.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)2),
tmp3);
// Put all together under a SEQUENCE tag
DerOutputStream out = new DerOutputStream();
out.write(DerValue.tag_Sequence, tmp);
return out.toByteArray();
}
protected byte[] engineGetEncoded(String encodingMethod)
throws IOException {
if ((encodingMethod != null) &&
(!encodingMethod.equalsIgnoreCase("ASN.1"))) {
throw new IllegalArgumentException("Only support ASN.1 format");
}
return engineGetEncoded();
}
protected String engineToString() {
StringBuffer sb = new StringBuffer();
sb.append("MD: " + mdName + "\n");
sb.append("MGF: MGF1" + mgfSpec.getDigestAlgorithm() + "\n");
sb.append("PSource: PSpecified " +
(p.length==0? "":Debug.toHexString(new BigInteger(p))) + "\n");
return sb.toString();
}
}