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package com.sun.crypto.provider;
import java.math.BigInteger;
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 =
ObjectIdentifier.of(KnownOIDs.MGF1);
private static ObjectIdentifier OID_PSpecified =
ObjectIdentifier.of(KnownOIDs.PSpecified);
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");
}
}
protected void engineInit(byte[] encoded) throws IOException {
DerInputStream der = DerValue.wrap(encoded).data();
var sub = der.getOptionalExplicitContextSpecific(0);
if (sub.isPresent()) {
mdName = AlgorithmId.parse(sub.get()).getName();
} else {
mdName = "SHA-1";
}
sub = der.getOptionalExplicitContextSpecific(1);
if (sub.isPresent()) {
AlgorithmId val = AlgorithmId.parse(sub.get());
if (!val.getOID().equals(OID_MGF1)) {
throw new IOException("Only MGF1 mgf is supported");
}
AlgorithmId params = AlgorithmId.parse(
new DerValue(val.getEncodedParams()));
mgfSpec = switch (params.getName()) {
case "SHA-1" -> MGF1ParameterSpec.SHA1;
case "SHA-224" -> MGF1ParameterSpec.SHA224;
case "SHA-256" -> MGF1ParameterSpec.SHA256;
case "SHA-384" -> MGF1ParameterSpec.SHA384;
case "SHA-512" -> MGF1ParameterSpec.SHA512;
case "SHA-512/224" -> MGF1ParameterSpec.SHA512_224;
case "SHA-512/256" -> MGF1ParameterSpec.SHA512_256;
default -> throw new IOException(
"Unrecognized message digest algorithm");
};
} else {
mgfSpec = MGF1ParameterSpec.SHA1;
}
sub = der.getOptionalExplicitContextSpecific(2);
if (sub.isPresent()) {
AlgorithmId val = AlgorithmId.parse(sub.get());
if (!val.getOID().equals(OID_PSpecified)) {
throw new IOException("Wrong OID for pSpecified");
}
p = DerValue.wrap(val.getEncodedParams()).getOctetString();
} else {
p = new byte[0];
}
der.atEnd();
}
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
T engineGetParameterSpec(Class paramSpec)
throws InvalidParameterSpecException {
if (paramSpec.isAssignableFrom(OAEPParameterSpec.class)) {
return paramSpec.cast(
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() {
StringBuilder sb = new StringBuilder();
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();
}
}