/*
* Copyright (c) 2003, 2010, 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
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package sun.security.provider.certpath;
import java.io.*;
import java.math.BigInteger;
import java.security.*;
import java.security.cert.CertificateException;
import java.security.cert.CertificateParsingException;
import java.security.cert.CertPathValidatorException;
import java.security.cert.X509Certificate;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import sun.misc.HexDumpEncoder;
import sun.security.x509.*;
import sun.security.util.*;
/**
* This class is used to process an OCSP response.
* The OCSP Response is defined
* in RFC 2560 and the ASN.1 encoding is as follows:
* <pre>
*
* OCSPResponse ::= SEQUENCE {
* responseStatus OCSPResponseStatus,
* responseBytes [0] EXPLICIT ResponseBytes OPTIONAL }
*
* OCSPResponseStatus ::= ENUMERATED {
* successful (0), --Response has valid confirmations
* malformedRequest (1), --Illegal confirmation request
* internalError (2), --Internal error in issuer
* tryLater (3), --Try again later
* --(4) is not used
* sigRequired (5), --Must sign the request
* unauthorized (6) --Request unauthorized
* }
*
* ResponseBytes ::= SEQUENCE {
* responseType OBJECT IDENTIFIER,
* response OCTET STRING }
*
* BasicOCSPResponse ::= SEQUENCE {
* tbsResponseData ResponseData,
* signatureAlgorithm AlgorithmIdentifier,
* signature BIT STRING,
* certs [0] EXPLICIT SEQUENCE OF Certificate OPTIONAL }
*
* The value for signature SHALL be computed on the hash of the DER
* encoding ResponseData.
*
* ResponseData ::= SEQUENCE {
* version [0] EXPLICIT Version DEFAULT v1,
* responderID ResponderID,
* producedAt GeneralizedTime,
* responses SEQUENCE OF SingleResponse,
* responseExtensions [1] EXPLICIT Extensions OPTIONAL }
*
* ResponderID ::= CHOICE {
* byName [1] Name,
* byKey [2] KeyHash }
*
* KeyHash ::= OCTET STRING -- SHA-1 hash of responder's public key
* (excluding the tag and length fields)
*
* SingleResponse ::= SEQUENCE {
* certID CertID,
* certStatus CertStatus,
* thisUpdate GeneralizedTime,
* nextUpdate [0] EXPLICIT GeneralizedTime OPTIONAL,
* singleExtensions [1] EXPLICIT Extensions OPTIONAL }
*
* CertStatus ::= CHOICE {
* good [0] IMPLICIT NULL,
* revoked [1] IMPLICIT RevokedInfo,
* unknown [2] IMPLICIT UnknownInfo }
*
* RevokedInfo ::= SEQUENCE {
* revocationTime GeneralizedTime,
* revocationReason [0] EXPLICIT CRLReason OPTIONAL }
*
* UnknownInfo ::= NULL -- this can be replaced with an enumeration
*
* </pre>
*
* @author Ram Marti
*/
public final class OCSPResponse {
public enum ResponseStatus {
SUCCESSFUL, // Response has valid confirmations
MALFORMED_REQUEST, // Illegal confirmation request
INTERNAL_ERROR, // Internal error in issuer
TRY_LATER, // Try again later
UNUSED, // is not used
SIG_REQUIRED, // Must sign the request
UNAUTHORIZED // Request unauthorized
};
private static ResponseStatus[] rsvalues = ResponseStatus.values();
private static final Debug DEBUG = Debug.getInstance("certpath");
private static final boolean dump = false;
private static final ObjectIdentifier OCSP_BASIC_RESPONSE_OID =
ObjectIdentifier.newInternal(new int[] { 1, 3, 6, 1, 5, 5, 7, 48, 1, 1});
private static final ObjectIdentifier OCSP_NONCE_EXTENSION_OID =
ObjectIdentifier.newInternal(new int[] { 1, 3, 6, 1, 5, 5, 7, 48, 1, 2});
// Certificate status CHOICE
private static final int CERT_STATUS_GOOD = 0;
private static final int CERT_STATUS_REVOKED = 1;
private static final int CERT_STATUS_UNKNOWN = 2;
// ResponderID CHOICE tags
private static final int NAME_TAG = 1;
private static final int KEY_TAG = 2;
// Object identifier for the OCSPSigning key purpose
private static final String KP_OCSP_SIGNING_OID = "1.3.6.1.5.5.7.3.9";
private final ResponseStatus responseStatus;
private final Map<CertId, SingleResponse> singleResponseMap;
// Maximum clock skew in milliseconds (15 minutes) allowed when checking
// validity of OCSP responses
private static final long MAX_CLOCK_SKEW = 900000;
/*
* Create an OCSP response from its ASN.1 DER encoding.
*/
// used by OCSPChecker
OCSPResponse(byte[] bytes, Date dateCheckedAgainst,
X509Certificate responderCert)
throws IOException, CertPathValidatorException {
// OCSPResponse
if (dump) {
HexDumpEncoder hexEnc = new HexDumpEncoder();
System.out.println("OCSPResponse bytes are...");
System.out.println(hexEnc.encode(bytes));
}
DerValue der = new DerValue(bytes);
if (der.tag != DerValue.tag_Sequence) {
throw new IOException("Bad encoding in OCSP response: " +
"expected ASN.1 SEQUENCE tag.");
}
DerInputStream derIn = der.getData();
// responseStatus
int status = derIn.getEnumerated();
if (status >= 0 && status < rsvalues.length) {
responseStatus = rsvalues[status];
} else {
// unspecified responseStatus
throw new IOException("Unknown OCSPResponse status: " + status);
}
if (DEBUG != null) {
DEBUG.println("OCSP response status: " + responseStatus);
}
if (responseStatus != ResponseStatus.SUCCESSFUL) {
// no need to continue, responseBytes are not set.
singleResponseMap = Collections.emptyMap();
return;
}
// responseBytes
der = derIn.getDerValue();
if (!der.isContextSpecific((byte)0)) {
throw new IOException("Bad encoding in responseBytes element " +
"of OCSP response: expected ASN.1 context specific tag 0.");
};
DerValue tmp = der.data.getDerValue();
if (tmp.tag != DerValue.tag_Sequence) {
throw new IOException("Bad encoding in responseBytes element " +
"of OCSP response: expected ASN.1 SEQUENCE tag.");
}
// responseType
derIn = tmp.data;
ObjectIdentifier responseType = derIn.getOID();
if (responseType.equals(OCSP_BASIC_RESPONSE_OID)) {
if (DEBUG != null) {
DEBUG.println("OCSP response type: basic");
}
} else {
if (DEBUG != null) {
DEBUG.println("OCSP response type: " + responseType);
}
throw new IOException("Unsupported OCSP response type: " +
responseType);
}
// BasicOCSPResponse
DerInputStream basicOCSPResponse =
new DerInputStream(derIn.getOctetString());
DerValue[] seqTmp = basicOCSPResponse.getSequence(2);
if (seqTmp.length < 3) {
throw new IOException("Unexpected BasicOCSPResponse value");
}
DerValue responseData = seqTmp[0];
// Need the DER encoded ResponseData to verify the signature later
byte[] responseDataDer = seqTmp[0].toByteArray();
// tbsResponseData
if (responseData.tag != DerValue.tag_Sequence) {
throw new IOException("Bad encoding in tbsResponseData " +
"element of OCSP response: expected ASN.1 SEQUENCE tag.");
}
DerInputStream seqDerIn = responseData.data;
DerValue seq = seqDerIn.getDerValue();
// version
if (seq.isContextSpecific((byte)0)) {
// seq[0] is version
if (seq.isConstructed() && seq.isContextSpecific()) {
//System.out.println ("version is available");
seq = seq.data.getDerValue();
int version = seq.getInteger();
if (seq.data.available() != 0) {
throw new IOException("Bad encoding in version " +
" element of OCSP response: bad format");
}
seq = seqDerIn.getDerValue();
}
}
// responderID
short tag = (byte)(seq.tag & 0x1f);
if (tag == NAME_TAG) {
if (DEBUG != null) {
X500Name responderName = new X500Name(seq.getData());
DEBUG.println("OCSP Responder name: " + responderName);
}
} else if (tag == KEY_TAG) {
// Ignore, for now
} else {
throw new IOException("Bad encoding in responderID element of " +
"OCSP response: expected ASN.1 context specific tag 0 or 1");
}
// producedAt
seq = seqDerIn.getDerValue();
if (DEBUG != null) {
Date producedAtDate = seq.getGeneralizedTime();
DEBUG.println("OCSP response produced at: " + producedAtDate);
}
// responses
DerValue[] singleResponseDer = seqDerIn.getSequence(1);
singleResponseMap
= new HashMap<CertId, SingleResponse>(singleResponseDer.length);
if (DEBUG != null) {
DEBUG.println("OCSP number of SingleResponses: "
+ singleResponseDer.length);
}
for (int i = 0; i < singleResponseDer.length; i++) {
SingleResponse singleResponse
= new SingleResponse(singleResponseDer[i]);
singleResponseMap.put(singleResponse.getCertId(), singleResponse);
}
// responseExtensions
if (seqDerIn.available() > 0) {
seq = seqDerIn.getDerValue();
if (seq.isContextSpecific((byte)1)) {
DerValue[] responseExtDer = seq.data.getSequence(3);
for (int i = 0; i < responseExtDer.length; i++) {
Extension responseExtension =
new Extension(responseExtDer[i]);
if (DEBUG != null) {
DEBUG.println("OCSP extension: " + responseExtension);
}
if (responseExtension.getExtensionId().equals(
OCSP_NONCE_EXTENSION_OID)) {
/*
ocspNonce =
responseExtension[i].getExtensionValue();
*/
} else if (responseExtension.isCritical()) {
throw new IOException(
"Unsupported OCSP critical extension: " +
responseExtension.getExtensionId());
}
}
}
}
// signatureAlgorithmId
AlgorithmId sigAlgId = AlgorithmId.parse(seqTmp[1]);
// check that the signature algorithm is not disabled.
AlgorithmChecker.check(sigAlgId);
// signature
byte[] signature = seqTmp[2].getBitString();
X509CertImpl[] x509Certs = null;
// if seq[3] is available , then it is a sequence of certificates
if (seqTmp.length > 3) {
// certs are available
DerValue seqCert = seqTmp[3];
if (!seqCert.isContextSpecific((byte)0)) {
throw new IOException("Bad encoding in certs element of " +
"OCSP response: expected ASN.1 context specific tag 0.");
}
DerValue[] certs = seqCert.getData().getSequence(3);
x509Certs = new X509CertImpl[certs.length];
try {
for (int i = 0; i < certs.length; i++) {
x509Certs[i] = new X509CertImpl(certs[i].toByteArray());
}
} catch (CertificateException ce) {
throw new IOException("Bad encoding in X509 Certificate", ce);
}
}
// Check whether the cert returned by the responder is trusted
if (x509Certs != null && x509Certs[0] != null) {
X509Certificate cert = x509Certs[0];
// First check if the cert matches the responder cert which
// was set locally.
if (cert.equals(responderCert)) {
// cert is trusted, now verify the signed response
// Next check if the cert was issued by the responder cert
// which was set locally.
} else if (cert.getIssuerX500Principal().equals(
responderCert.getSubjectX500Principal())) {
// check the certificate algorithm
AlgorithmChecker.check(cert);
// Check for the OCSPSigning key purpose
try {
List<String> keyPurposes = cert.getExtendedKeyUsage();
if (keyPurposes == null ||
!keyPurposes.contains(KP_OCSP_SIGNING_OID)) {
throw new CertPathValidatorException(
"Responder's certificate not valid for signing " +
"OCSP responses");
}
} catch (CertificateParsingException cpe) {
// assume cert is not valid for signing
throw new CertPathValidatorException(
"Responder's certificate not valid for signing " +
"OCSP responses", cpe);
}
// verify the signature
try {
cert.verify(responderCert.getPublicKey());
responderCert = cert;
// cert is trusted, now verify the signed response
} catch (GeneralSecurityException e) {
responderCert = null;
}
}
}
// Confirm that the signed response was generated using the public
// key from the trusted responder cert
if (responderCert != null) {
if (!verifyResponse(responseDataDer, responderCert,
sigAlgId, signature)) {
throw new CertPathValidatorException(
"Error verifying OCSP Responder's signature");
}
} else {
// Need responder's cert in order to verify the signature
throw new CertPathValidatorException(
"Unable to verify OCSP Responder's signature");
}
}
/**
* Returns the OCSP ResponseStatus.
*/
ResponseStatus getResponseStatus() {
return responseStatus;
}
/*
* Verify the signature of the OCSP response.
* The responder's cert is implicitly trusted.
*/
private boolean verifyResponse(byte[] responseData, X509Certificate cert,
AlgorithmId sigAlgId, byte[] signBytes)
throws CertPathValidatorException {
try {
Signature respSignature = Signature.getInstance(sigAlgId.getName());
respSignature.initVerify(cert);
respSignature.update(responseData);
if (respSignature.verify(signBytes)) {
if (DEBUG != null) {
DEBUG.println("Verified signature of OCSP Responder");
}
return true;
} else {
if (DEBUG != null) {
DEBUG.println(
"Error verifying signature of OCSP Responder");
}
return false;
}
} catch (InvalidKeyException ike) {
throw new CertPathValidatorException(ike);
} catch (NoSuchAlgorithmException nsae) {
throw new CertPathValidatorException(nsae);
} catch (SignatureException se) {
throw new CertPathValidatorException(se);
}
}
/**
* Returns the SingleResponse of the specified CertId, or null if
* there is no response for that CertId.
*/
SingleResponse getSingleResponse(CertId certId) {
return singleResponseMap.get(certId);
}
/*
* A class representing a single OCSP response.
*/
final static class SingleResponse implements OCSP.RevocationStatus {
private final CertId certId;
private final CertStatus certStatus;
private final Date thisUpdate;
private final Date nextUpdate;
private final Date revocationTime;
private static Reason[] values = Reason.values();
private final Reason revocationReason;
private SingleResponse(DerValue der) throws IOException {
if (der.tag != DerValue.tag_Sequence) {
throw new IOException("Bad ASN.1 encoding in SingleResponse");
}
DerInputStream tmp = der.data;
certId = new CertId(tmp.getDerValue().data);
DerValue derVal = tmp.getDerValue();
short tag = (byte)(derVal.tag & 0x1f);
if (tag == CERT_STATUS_REVOKED) {
certStatus = CertStatus.REVOKED;
revocationTime = derVal.data.getGeneralizedTime();
if (derVal.data.available() != 0) {
DerValue dv = derVal.data.getDerValue();
tag = (byte)(dv.tag & 0x1f);
if (tag == 0) {
int reason = dv.data.getEnumerated();
// if reason out-of-range just leave as UNSPECIFIED
if (reason >= 0 && reason < values.length) {
revocationReason = values[reason];
} else {
revocationReason = Reason.UNSPECIFIED;
}
} else {
revocationReason = Reason.UNSPECIFIED;
}
} else {
revocationReason = Reason.UNSPECIFIED;
}
// RevokedInfo
if (DEBUG != null) {
DEBUG.println("Revocation time: " + revocationTime);
DEBUG.println("Revocation reason: " + revocationReason);
}
} else {
revocationTime = null;
revocationReason = Reason.UNSPECIFIED;
if (tag == CERT_STATUS_GOOD) {
certStatus = CertStatus.GOOD;
} else if (tag == CERT_STATUS_UNKNOWN) {
certStatus = CertStatus.UNKNOWN;
} else {
throw new IOException("Invalid certificate status");
}
}
thisUpdate = tmp.getGeneralizedTime();
if (tmp.available() == 0) {
// we are done
nextUpdate = null;
} else {
derVal = tmp.getDerValue();
tag = (byte)(derVal.tag & 0x1f);
if (tag == 0) {
// next update
nextUpdate = derVal.data.getGeneralizedTime();
} else {
nextUpdate = null;
}
}
// singleExtensions
if (tmp.available() > 0) {
derVal = tmp.getDerValue();
if (derVal.isContextSpecific((byte)1)) {
DerValue[] singleExtDer = derVal.data.getSequence(3);
for (int i = 0; i < singleExtDer.length; i++) {
Extension ext = new Extension(singleExtDer[i]);
if (DEBUG != null) {
DEBUG.println("OCSP single extension: " + ext);
}
if (ext.isCritical()) {
throw new IOException(
"Unsupported OCSP critical extension: " +
ext.getExtensionId());
}
}
}
}
long now = System.currentTimeMillis();
Date nowPlusSkew = new Date(now + MAX_CLOCK_SKEW);
Date nowMinusSkew = new Date(now - MAX_CLOCK_SKEW);
if (DEBUG != null) {
String until = "";
if (nextUpdate != null) {
until = " until " + nextUpdate;
}
DEBUG.println("Response's validity interval is from " +
thisUpdate + until);
}
// Check that the test date is within the validity interval
if ((thisUpdate != null && nowPlusSkew.before(thisUpdate)) ||
(nextUpdate != null && nowMinusSkew.after(nextUpdate))) {
if (DEBUG != null) {
DEBUG.println("Response is unreliable: its validity " +
"interval is out-of-date");
}
throw new IOException("Response is unreliable: its validity " +
"interval is out-of-date");
}
}
/*
* Return the certificate's revocation status code
*/
@Override public CertStatus getCertStatus() {
return certStatus;
}
private CertId getCertId() {
return certId;
}
@Override public Date getRevocationTime() {
return (Date) revocationTime.clone();
}
@Override public Reason getRevocationReason() {
return revocationReason;
}
/**
* Construct a string representation of a single OCSP response.
*/
@Override public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("SingleResponse: \n");
sb.append(certId);
sb.append("\nCertStatus: "+ certStatus + "\n");
if (certStatus == CertStatus.REVOKED) {
sb.append("revocationTime is " + revocationTime + "\n");
sb.append("revocationReason is " + revocationReason + "\n");
}
sb.append("thisUpdate is " + thisUpdate + "\n");
if (nextUpdate != null) {
sb.append("nextUpdate is " + nextUpdate + "\n");
}
return sb.toString();
}
}
}