/*
* Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* 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).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.security.rsa;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.math.BigInteger;
import java.util.Arrays;
import java.security.*;
import java.security.interfaces.*;
import sun.security.util.*;
import sun.security.x509.AlgorithmId;
/**
* PKCS#1 RSA signatures with the various message digest algorithms.
* This file contains an abstract base class with all the logic plus
* a nested static class for each of the message digest algorithms
* (see end of the file). We support MD2, MD5, SHA-1, SHA-256, SHA-384,
* and SHA-512.
*
* @since 1.5
* @author Andreas Sterbenz
*/
public abstract class RSASignature extends SignatureSpi {
// we sign an ASN.1 SEQUENCE of AlgorithmId and digest
// it has the form 30:xx:30:0c:[digestOID]:05:00:04:xx:[digest]
// this means the encoded length is (8 + digestOID.length + digest.length)
private static final int baseLength = 8;
// object identifier for the message digest algorithm used
private final ObjectIdentifier digestOID;
// length of the encoded signature blob
private final int encodedLength;
// message digest implementation we use
private final MessageDigest md;
// flag indicating whether the digest is reset
private boolean digestReset;
// private key, if initialized for signing
private RSAPrivateKey privateKey;
// public key, if initialized for verifying
private RSAPublicKey publicKey;
// padding to use, set when the initSign/initVerify is called
private RSAPadding padding;
/**
* Construct a new RSASignature. Used by subclasses.
*/
RSASignature(String algorithm, ObjectIdentifier digestOID, int oidLength) {
this.digestOID = digestOID;
try {
md = MessageDigest.getInstance(algorithm);
} catch (NoSuchAlgorithmException e) {
throw new ProviderException(e);
}
digestReset = true;
encodedLength = baseLength + oidLength + md.getDigestLength();
}
// initialize for verification. See JCA doc
protected void engineInitVerify(PublicKey publicKey)
throws InvalidKeyException {
RSAPublicKey rsaKey = (RSAPublicKey)RSAKeyFactory.toRSAKey(publicKey);
this.privateKey = null;
this.publicKey = rsaKey;
initCommon(rsaKey, null);
}
// initialize for signing. See JCA doc
protected void engineInitSign(PrivateKey privateKey)
throws InvalidKeyException {
engineInitSign(privateKey, null);
}
// initialize for signing. See JCA doc
protected void engineInitSign(PrivateKey privateKey, SecureRandom random)
throws InvalidKeyException {
RSAPrivateKey rsaKey = (RSAPrivateKey)RSAKeyFactory.toRSAKey(privateKey);
this.privateKey = rsaKey;
this.publicKey = null;
initCommon(rsaKey, random);
}
/**
* Init code common to sign and verify.
*/
private void initCommon(RSAKey rsaKey, SecureRandom random)
throws InvalidKeyException {
resetDigest();
int keySize = RSACore.getByteLength(rsaKey);
try {
padding = RSAPadding.getInstance
(RSAPadding.PAD_BLOCKTYPE_1, keySize, random);
} catch (InvalidAlgorithmParameterException iape) {
throw new InvalidKeyException(iape.getMessage());
}
int maxDataSize = padding.getMaxDataSize();
if (encodedLength > maxDataSize) {
throw new InvalidKeyException
("Key is too short for this signature algorithm");
}
}
/**
* Reset the message digest if it is not already reset.
*/
private void resetDigest() {
if (digestReset == false) {
md.reset();
digestReset = true;
}
}
/**
* Return the message digest value.
*/
private byte[] getDigestValue() {
digestReset = true;
return md.digest();
}
// update the signature with the plaintext data. See JCA doc
protected void engineUpdate(byte b) throws SignatureException {
md.update(b);
digestReset = false;
}
// update the signature with the plaintext data. See JCA doc
protected void engineUpdate(byte[] b, int off, int len)
throws SignatureException {
md.update(b, off, len);
digestReset = false;
}
// update the signature with the plaintext data. See JCA doc
protected void engineUpdate(ByteBuffer b) {
md.update(b);
digestReset = false;
}
// sign the data and return the signature. See JCA doc
protected byte[] engineSign() throws SignatureException {
byte[] digest = getDigestValue();
try {
byte[] encoded = encodeSignature(digestOID, digest);
byte[] padded = padding.pad(encoded);
byte[] encrypted = RSACore.rsa(padded, privateKey);
return encrypted;
} catch (GeneralSecurityException e) {
throw new SignatureException("Could not sign data", e);
} catch (IOException e) {
throw new SignatureException("Could not encode data", e);
}
}
// verify the data and return the result. See JCA doc
protected boolean engineVerify(byte[] sigBytes) throws SignatureException {
byte[] digest = getDigestValue();
try {
byte[] decrypted = RSACore.rsa(sigBytes, publicKey);
byte[] unpadded = padding.unpad(decrypted);
byte[] decodedDigest = decodeSignature(digestOID, unpadded);
return Arrays.equals(digest, decodedDigest);
} catch (javax.crypto.BadPaddingException e) {
// occurs if the app has used the wrong RSA public key
// or if sigBytes is invalid
// return false rather than propagating the exception for
// compatibility/ease of use
return false;
} catch (GeneralSecurityException e) {
throw new SignatureException("Signature verification failed", e);
} catch (IOException e) {
throw new SignatureException("Signature encoding error", e);
}
}
/**
* Encode the digest, return the to-be-signed data.
* Also used by the PKCS#11 provider.
*/
public static byte[] encodeSignature(ObjectIdentifier oid, byte[] digest)
throws IOException {
DerOutputStream out = new DerOutputStream();
new AlgorithmId(oid).encode(out);
out.putOctetString(digest);
DerValue result = new DerValue(DerValue.tag_Sequence, out.toByteArray());
return result.toByteArray();
}
/**
* Decode the signature data. Verify that the object identifier matches
* and return the message digest.
*/
public static byte[] decodeSignature(ObjectIdentifier oid, byte[] signature)
throws IOException {
DerInputStream in = new DerInputStream(signature);
DerValue[] values = in.getSequence(2);
if ((values.length != 2) || (in.available() != 0)) {
throw new IOException("SEQUENCE length error");
}
AlgorithmId algId = AlgorithmId.parse(values[0]);
if (algId.getOID().equals(oid) == false) {
throw new IOException("ObjectIdentifier mismatch: " + algId.getOID());
}
if (algId.getEncodedParams() != null) {
throw new IOException("Unexpected AlgorithmId parameters");
}
byte[] digest = values[1].getOctetString();
return digest;
}
// set parameter, not supported. See JCA doc
protected void engineSetParameter(String param, Object value)
throws InvalidParameterException {
throw new UnsupportedOperationException("setParameter() not supported");
}
// get parameter, not supported. See JCA doc
protected Object engineGetParameter(String param)
throws InvalidParameterException {
throw new UnsupportedOperationException("getParameter() not supported");
}
// Nested class for MD2withRSA signatures
public static final class MD2withRSA extends RSASignature {
public MD2withRSA() {
super("MD2", AlgorithmId.MD2_oid, 10);
}
}
// Nested class for MD5withRSA signatures
public static final class MD5withRSA extends RSASignature {
public MD5withRSA() {
super("MD5", AlgorithmId.MD5_oid, 10);
}
}
// Nested class for SHA1withRSA signatures
public static final class SHA1withRSA extends RSASignature {
public SHA1withRSA() {
super("SHA-1", AlgorithmId.SHA_oid, 7);
}
}
// Nested class for SHA256withRSA signatures
public static final class SHA256withRSA extends RSASignature {
public SHA256withRSA() {
super("SHA-256", AlgorithmId.SHA256_oid, 11);
}
}
// Nested class for SHA384withRSA signatures
public static final class SHA384withRSA extends RSASignature {
public SHA384withRSA() {
super("SHA-384", AlgorithmId.SHA384_oid, 11);
}
}
// Nested class for SHA512withRSA signatures
public static final class SHA512withRSA extends RSASignature {
public SHA512withRSA() {
super("SHA-512", AlgorithmId.SHA512_oid, 11);
}
}
}