| /* |
| * Copyright (C) 2018 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.ike.ikev2.message; |
| |
| import static com.android.ike.ikev2.SaProposal.DhGroup; |
| import static com.android.ike.ikev2.SaProposal.EncryptionAlgorithm; |
| import static com.android.ike.ikev2.SaProposal.IntegrityAlgorithm; |
| import static com.android.ike.ikev2.SaProposal.PseudorandomFunction; |
| |
| import android.annotation.IntDef; |
| import android.util.ArraySet; |
| import android.util.Pair; |
| |
| import com.android.ike.ikev2.SaProposal; |
| import com.android.ike.ikev2.exceptions.IkeException; |
| import com.android.ike.ikev2.exceptions.InvalidSyntaxException; |
| import com.android.ike.ikev2.exceptions.NoValidProposalChosenException; |
| import com.android.internal.annotations.VisibleForTesting; |
| |
| import java.lang.annotation.Retention; |
| import java.lang.annotation.RetentionPolicy; |
| import java.nio.ByteBuffer; |
| import java.util.ArrayList; |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.Objects; |
| import java.util.Set; |
| |
| /** |
| * IkeSaPayload represents a Security Association payload. It contains one or more {@link Proposal}. |
| * |
| * @see <a href="https://tools.ietf.org/html/rfc7296#section-3.3">RFC 7296, Internet Key Exchange |
| * Protocol Version 2 (IKEv2)</a> |
| */ |
| public final class IkeSaPayload extends IkePayload { |
| public final boolean isSaResponse; |
| public final List<Proposal> proposalList; |
| /** |
| * Construct an instance of IkeSaPayload for decoding an inbound packet. |
| * |
| * @param critical indicates if this payload is critical. Ignored in supported payload as |
| * instructed by the RFC 7296. |
| * @param isResp indicates if this payload is in a response message. |
| * @param payloadBody the encoded payload body in byte array. |
| */ |
| IkeSaPayload(boolean critical, boolean isResp, byte[] payloadBody) throws IkeException { |
| super(IkePayload.PAYLOAD_TYPE_SA, critical); |
| |
| ByteBuffer inputBuffer = ByteBuffer.wrap(payloadBody); |
| proposalList = new LinkedList<>(); |
| while (inputBuffer.hasRemaining()) { |
| Proposal proposal = Proposal.readFrom(inputBuffer); |
| proposalList.add(proposal); |
| } |
| |
| // An SA response must have exactly one SA proposal. |
| if (isResp && proposalList.size() != 1) { |
| throw new InvalidSyntaxException( |
| "Expected only one negotiated proposal from SA response: " |
| + "Multiple negotiated proposals found."); |
| } |
| isSaResponse = isResp; |
| } |
| |
| /** |
| * Construct an instance of IkeSaPayload for building outbound packet. |
| * |
| * <p>The length of spis must be the same as saProposals. |
| * |
| * @param isResp indicates if this payload is in a response message. |
| * @param isIkeSa indicates if this payload is for IKE SA or Child SA |
| * @param spiSize the size of attached SPIs. |
| * @param spis the array of all attached SPIs. |
| * @param saProposals the array of all SA Proposals. |
| */ |
| public IkeSaPayload( |
| boolean isResp, boolean isIkeSa, byte spiSize, long[] spis, SaProposal[] saProposals) { |
| super(IkePayload.PAYLOAD_TYPE_SA, false); |
| |
| if (saProposals.length < 1 |
| || isResp && (saProposals.length > 1) |
| || saProposals.length != spis.length) { |
| throw new IllegalArgumentException("Invalid SA payload."); |
| } |
| |
| // TODO: Check that saProposals.length <= 255 in IkeSessionOptions and ChildSessionOptions |
| isSaResponse = isResp; |
| |
| proposalList = new ArrayList<Proposal>(saProposals.length); |
| int protocolId = isIkeSa ? PROTOCOL_ID_IKE : PROTOCOL_ID_ESP; |
| for (int i = 0; i < saProposals.length; i++) { |
| // Proposal number must start from 1. |
| Proposal proposal = |
| new Proposal( |
| (byte) (i + 1) /*proposal number*/, |
| protocolId, |
| spiSize, |
| spis[i], |
| saProposals[i], |
| false /*does not have unrecognized Transform*/); |
| proposalList.add(proposal); |
| } |
| } |
| |
| /** |
| * Construct an instance of IkeSaPayload for building outbound IKE initial setup request. |
| * |
| * <p>According to RFC 7296, for an initial IKE SA negotiation, no SPI is included in SA |
| * Proposal. IKE library, as a client, only supports requesting this initial negotiation. |
| * |
| * @param saProposals the array of all SA Proposals. |
| */ |
| public IkeSaPayload(SaProposal[] saProposals) { |
| this( |
| false /*is request*/, |
| true /*is IKE SA*/, |
| (byte) 0, |
| new long[saProposals.length], |
| saProposals); |
| } |
| |
| /** |
| * Validate and return the negotiated SA proposal from the received SA payload. |
| * |
| * @param reqSaPayload SA payload from SA initiator to validate against. |
| * @return the validated negotiated SA proposal. |
| * @throws NoValidProposalChosenException if received SA proposal is invalid. |
| */ |
| public SaProposal getVerifiedNegotiatedProposal(IkeSaPayload reqSaPayload) |
| throws NoValidProposalChosenException { |
| if (!isSaResponse) { |
| throw new UnsupportedOperationException( |
| "Cannot get negotiated SA proposal from a request message."); |
| } |
| |
| // If negotiated proposal has an unrecognized Transform, throw an exception. |
| Proposal respProposal = proposalList.get(0); |
| if (respProposal.hasUnrecognizedTransform) { |
| throw new NoValidProposalChosenException( |
| "Negotiated proposal has unrecognized Transform."); |
| } |
| |
| // In SA request payload, the first proposal MUST be 1, and subsequent proposals MUST be one |
| // more than the previous proposal. In SA response payload, the negotiated proposal number |
| // MUST match the selected proposal number in SA request Payload. |
| int negotiatedProposalNum = respProposal.number; |
| List<Proposal> reqProposalList = reqSaPayload.proposalList; |
| if (negotiatedProposalNum < 1 || negotiatedProposalNum > reqProposalList.size()) { |
| throw new NoValidProposalChosenException( |
| "Negotiated proposal has invalid proposal number."); |
| } |
| |
| Proposal reqProposal = reqProposalList.get(negotiatedProposalNum - 1); |
| if (!respProposal.isNegotiatedFrom(reqProposal)) { |
| throw new NoValidProposalChosenException("Invalid negotiated proposal."); |
| } |
| return respProposal.saProposal; |
| } |
| |
| @VisibleForTesting |
| interface TransformDecoder { |
| Transform[] decodeTransforms(int count, ByteBuffer inputBuffer) throws IkeException; |
| } |
| |
| // TODO: Add another constructor for building outbound message. |
| |
| /** |
| * Proposal represents a set contains cryptographic algorithms and key generating materials. It |
| * contains multiple {@link Transform}. |
| * |
| * @see <a href="https://tools.ietf.org/html/rfc7296#section-3.3.1">RFC 7296, Internet Key |
| * Exchange Protocol Version 2 (IKEv2)</a> |
| * <p>Proposals with an unrecognized Protocol ID, containing an unrecognized Transform Type |
| * or lacking a necessary Transform Type shall be ignored when processing a received SA |
| * Payload. |
| */ |
| public static final class Proposal { |
| private static final byte LAST_PROPOSAL = 0; |
| private static final byte NOT_LAST_PROPOSAL = 2; |
| |
| private static final int PROPOSAL_RESERVED_FIELD_LEN = 1; |
| private static final int PROPOSAL_HEADER_LEN = 8; |
| |
| @VisibleForTesting |
| static TransformDecoder sTransformDecoder = |
| new TransformDecoder() { |
| @Override |
| public Transform[] decodeTransforms(int count, ByteBuffer inputBuffer) |
| throws IkeException { |
| Transform[] transformArray = new Transform[count]; |
| for (int i = 0; i < count; i++) { |
| Transform transform = Transform.readFrom(inputBuffer); |
| if (transform.isSupported) { |
| transformArray[i] = transform; |
| } |
| } |
| return transformArray; |
| } |
| }; |
| |
| public final byte number; |
| /** All supported protocol will fall into {@link ProtocolId} */ |
| public final int protocolId; |
| |
| public final byte spiSize; |
| public final long spi; |
| |
| public final SaProposal saProposal; |
| |
| public final boolean hasUnrecognizedTransform; |
| |
| // TODO: Validate this proposal |
| |
| @VisibleForTesting |
| Proposal( |
| byte number, |
| int protocolId, |
| byte spiSize, |
| long spi, |
| SaProposal saProposal, |
| boolean hasUnrecognizedTransform) { |
| this.number = number; |
| this.protocolId = protocolId; |
| this.spiSize = spiSize; |
| this.spi = spi; |
| this.saProposal = saProposal; |
| this.hasUnrecognizedTransform = hasUnrecognizedTransform; |
| } |
| |
| @VisibleForTesting |
| static Proposal readFrom(ByteBuffer inputBuffer) throws IkeException { |
| byte isLast = inputBuffer.get(); |
| if (isLast != LAST_PROPOSAL && isLast != NOT_LAST_PROPOSAL) { |
| throw new InvalidSyntaxException( |
| "Invalid value of Last Proposal Substructure: " + isLast); |
| } |
| // Skip RESERVED byte |
| inputBuffer.get(new byte[PROPOSAL_RESERVED_FIELD_LEN]); |
| |
| int length = Short.toUnsignedInt(inputBuffer.getShort()); |
| byte number = inputBuffer.get(); |
| int protocolId = Byte.toUnsignedInt(inputBuffer.get()); |
| |
| byte spiSize = inputBuffer.get(); |
| int transformCount = Byte.toUnsignedInt(inputBuffer.get()); |
| |
| // TODO: Add check: spiSize must be 0 in initial IKE SA negotiation |
| // spiSize should be either 8 for IKE or 4 for IPsec. |
| long spi = SPI_NOT_INCLUDED; |
| switch (spiSize) { |
| case SPI_LEN_NOT_INCLUDED: |
| // No SPI attached for IKE initial exchange. |
| break; |
| case SPI_LEN_IPSEC: |
| spi = Integer.toUnsignedLong(inputBuffer.getInt()); |
| break; |
| case SPI_LEN_IKE: |
| spi = inputBuffer.getLong(); |
| break; |
| default: |
| throw new InvalidSyntaxException( |
| "Invalid value of spiSize in Proposal Substructure: " + spiSize); |
| } |
| |
| Transform[] transformArray = |
| sTransformDecoder.decodeTransforms(transformCount, inputBuffer); |
| // TODO: Validate that sum of all Transforms' lengths plus Proposal header length equals |
| // to Proposal's length. |
| |
| List<EncryptionTransform> encryptAlgoList = new LinkedList<>(); |
| List<PrfTransform> prfList = new LinkedList<>(); |
| List<IntegrityTransform> integAlgoList = new LinkedList<>(); |
| List<DhGroupTransform> dhGroupList = new LinkedList<>(); |
| List<EsnTransform> esnList = new LinkedList<>(); |
| |
| boolean hasUnrecognizedTransform = false; |
| |
| for (Transform transform : transformArray) { |
| switch (transform.type) { |
| case Transform.TRANSFORM_TYPE_ENCR: |
| encryptAlgoList.add((EncryptionTransform) transform); |
| break; |
| case Transform.TRANSFORM_TYPE_PRF: |
| prfList.add((PrfTransform) transform); |
| break; |
| case Transform.TRANSFORM_TYPE_INTEG: |
| integAlgoList.add((IntegrityTransform) transform); |
| break; |
| case Transform.TRANSFORM_TYPE_DH: |
| dhGroupList.add((DhGroupTransform) transform); |
| break; |
| case Transform.TRANSFORM_TYPE_ESN: |
| esnList.add((EsnTransform) transform); |
| break; |
| default: |
| hasUnrecognizedTransform = true; |
| } |
| } |
| |
| SaProposal saProposal = |
| new SaProposal( |
| protocolId, |
| encryptAlgoList.toArray( |
| new EncryptionTransform[encryptAlgoList.size()]), |
| prfList.toArray(new PrfTransform[prfList.size()]), |
| integAlgoList.toArray(new IntegrityTransform[integAlgoList.size()]), |
| dhGroupList.toArray(new DhGroupTransform[dhGroupList.size()]), |
| esnList.toArray(new EsnTransform[esnList.size()])); |
| |
| return new Proposal( |
| number, protocolId, spiSize, spi, saProposal, hasUnrecognizedTransform); |
| } |
| // TODO: Add another contructor for encoding. |
| |
| /** Package private */ |
| boolean isNegotiatedFrom(Proposal reqProposal) { |
| if (protocolId != reqProposal.protocolId || number != reqProposal.number) { |
| return false; |
| } |
| return saProposal.isNegotiatedFrom(reqProposal.saProposal); |
| } |
| |
| protected void encodeToByteBuffer(boolean isLast, ByteBuffer byteBuffer) { |
| Transform[] allTransforms = saProposal.getAllTransforms(); |
| byte isLastIndicator = isLast ? LAST_PROPOSAL : NOT_LAST_PROPOSAL; |
| |
| byteBuffer |
| .put(isLastIndicator) |
| .put(new byte[PROPOSAL_RESERVED_FIELD_LEN]) |
| .putShort((short) getProposalLength()) |
| .put(number) |
| .put((byte) protocolId) |
| .put(spiSize) |
| .put((byte) allTransforms.length); |
| |
| switch (spiSize) { |
| case SPI_LEN_NOT_INCLUDED: |
| // No SPI attached for IKE initial exchange. |
| break; |
| case SPI_LEN_IPSEC: |
| byteBuffer.putInt((int) spi); |
| break; |
| case SPI_LEN_IKE: |
| byteBuffer.putLong((long) spi); |
| break; |
| default: |
| throw new IllegalArgumentException( |
| "Invalid value of spiSize in Proposal Substructure: " + spiSize); |
| } |
| |
| // Encode all Transform. |
| for (int i = 0; i < allTransforms.length; i++) { |
| // The last transform has the isLast flag set to true. |
| allTransforms[i].encodeToByteBuffer(i == allTransforms.length - 1, byteBuffer); |
| } |
| } |
| |
| protected int getProposalLength() { |
| int len = PROPOSAL_HEADER_LEN + spiSize; |
| |
| Transform[] allTransforms = saProposal.getAllTransforms(); |
| for (Transform t : allTransforms) len += t.getTransformLength(); |
| return len; |
| } |
| } |
| |
| @VisibleForTesting |
| interface AttributeDecoder { |
| List<Attribute> decodeAttributes(int length, ByteBuffer inputBuffer) throws IkeException; |
| } |
| |
| /** |
| * Transform is an abstract base class that represents the common information for all Transform |
| * types. It may contain one or more {@link Attribute}. |
| * |
| * @see <a href="https://tools.ietf.org/html/rfc7296#section-3.3.2">RFC 7296, Internet Key |
| * Exchange Protocol Version 2 (IKEv2)</a> |
| * <p>Transforms with unrecognized Transform ID or containing unrecognized Attribute Type |
| * shall be ignored when processing received SA payload. |
| */ |
| public abstract static class Transform { |
| |
| @Retention(RetentionPolicy.SOURCE) |
| @IntDef({ |
| TRANSFORM_TYPE_ENCR, |
| TRANSFORM_TYPE_PRF, |
| TRANSFORM_TYPE_INTEG, |
| TRANSFORM_TYPE_DH, |
| TRANSFORM_TYPE_ESN |
| }) |
| public @interface TransformType {} |
| |
| public static final int TRANSFORM_TYPE_ENCR = 1; |
| public static final int TRANSFORM_TYPE_PRF = 2; |
| public static final int TRANSFORM_TYPE_INTEG = 3; |
| public static final int TRANSFORM_TYPE_DH = 4; |
| public static final int TRANSFORM_TYPE_ESN = 5; |
| |
| private static final byte LAST_TRANSFORM = 0; |
| private static final byte NOT_LAST_TRANSFORM = 3; |
| |
| // Length of reserved field of a Transform. |
| private static final int TRANSFORM_RESERVED_FIELD_LEN = 1; |
| |
| // Length of the Transform that with no Attribute. |
| protected static final int BASIC_TRANSFORM_LEN = 8; |
| |
| // TODO: Add constants for supported algorithms |
| |
| @VisibleForTesting |
| static AttributeDecoder sAttributeDecoder = |
| new AttributeDecoder() { |
| public List<Attribute> decodeAttributes(int length, ByteBuffer inputBuffer) |
| throws IkeException { |
| List<Attribute> list = new LinkedList<>(); |
| int parsedLength = BASIC_TRANSFORM_LEN; |
| while (parsedLength < length) { |
| Pair<Attribute, Integer> pair = Attribute.readFrom(inputBuffer); |
| parsedLength += pair.second; |
| list.add(pair.first); |
| } |
| // TODO: Validate that parsedLength equals to length. |
| return list; |
| } |
| }; |
| |
| // Only supported type falls into {@link TransformType} |
| public final int type; |
| public final int id; |
| public final boolean isSupported; |
| |
| /** Construct an instance of Transform for building an outbound packet. */ |
| protected Transform(int type, int id) { |
| this.type = type; |
| this.id = id; |
| if (!isSupportedTransformId(id)) { |
| throw new IllegalArgumentException( |
| "Unsupported " + getTransformTypeString() + " Algorithm ID: " + id); |
| } |
| this.isSupported = true; |
| } |
| |
| /** Construct an instance of Transform for decoding an inbound packet. */ |
| protected Transform(int type, int id, List<Attribute> attributeList) { |
| this.type = type; |
| this.id = id; |
| this.isSupported = |
| isSupportedTransformId(id) && !hasUnrecognizedAttribute(attributeList); |
| } |
| |
| @VisibleForTesting |
| static Transform readFrom(ByteBuffer inputBuffer) throws IkeException { |
| byte isLast = inputBuffer.get(); |
| if (isLast != LAST_TRANSFORM && isLast != NOT_LAST_TRANSFORM) { |
| throw new InvalidSyntaxException( |
| "Invalid value of Last Transform Substructure: " + isLast); |
| } |
| |
| // Skip RESERVED byte |
| inputBuffer.get(new byte[TRANSFORM_RESERVED_FIELD_LEN]); |
| |
| int length = Short.toUnsignedInt(inputBuffer.getShort()); |
| int type = Byte.toUnsignedInt(inputBuffer.get()); |
| |
| // Skip RESERVED byte |
| inputBuffer.get(new byte[TRANSFORM_RESERVED_FIELD_LEN]); |
| |
| int id = Short.toUnsignedInt(inputBuffer.getShort()); |
| |
| // Decode attributes |
| List<Attribute> attributeList = sAttributeDecoder.decodeAttributes(length, inputBuffer); |
| |
| validateAttributeUniqueness(attributeList); |
| |
| switch (type) { |
| case TRANSFORM_TYPE_ENCR: |
| return new EncryptionTransform(id, attributeList); |
| case TRANSFORM_TYPE_PRF: |
| return new PrfTransform(id, attributeList); |
| case TRANSFORM_TYPE_INTEG: |
| return new IntegrityTransform(id, attributeList); |
| case TRANSFORM_TYPE_DH: |
| return new DhGroupTransform(id, attributeList); |
| case TRANSFORM_TYPE_ESN: |
| return new EsnTransform(id, attributeList); |
| default: |
| return new UnrecognizedTransform(type, id, attributeList); |
| } |
| } |
| |
| // Throw InvalidSyntaxException if there are multiple Attributes of the same type |
| private static void validateAttributeUniqueness(List<Attribute> attributeList) |
| throws IkeException { |
| Set<Integer> foundTypes = new ArraySet<>(); |
| for (Attribute attr : attributeList) { |
| if (!foundTypes.add(attr.type)) { |
| throw new InvalidSyntaxException( |
| "There are multiple Attributes of the same type. "); |
| } |
| } |
| } |
| |
| // Check if there is Attribute with unrecognized type. |
| protected abstract boolean hasUnrecognizedAttribute(List<Attribute> attributeList); |
| |
| // Check if this Transform ID is supported. |
| protected abstract boolean isSupportedTransformId(int id); |
| |
| // Encode Transform to a ByteBuffer. |
| protected abstract void encodeToByteBuffer(boolean isLast, ByteBuffer byteBuffer); |
| |
| // Get entire Transform length. |
| protected abstract int getTransformLength(); |
| |
| protected void encodeBasicTransformToByteBuffer(boolean isLast, ByteBuffer byteBuffer) { |
| byte isLastIndicator = isLast ? LAST_TRANSFORM : NOT_LAST_TRANSFORM; |
| byteBuffer |
| .put(isLastIndicator) |
| .put(new byte[TRANSFORM_RESERVED_FIELD_LEN]) |
| .putShort((short) getTransformLength()) |
| .put((byte) type) |
| .put(new byte[TRANSFORM_RESERVED_FIELD_LEN]) |
| .putShort((short) id); |
| } |
| |
| /** |
| * Get Tranform Type as a String. |
| * |
| * @return Tranform Type as a String. |
| */ |
| public abstract String getTransformTypeString(); |
| |
| // TODO: Add abstract getTransformIdString() to return specific algorithm/dhGroup name |
| } |
| |
| /** |
| * EncryptionTransform represents an encryption algorithm. It may contain an Atrribute |
| * specifying the key length. |
| * |
| * @see <a href="https://tools.ietf.org/html/rfc7296#section-3.3.2">RFC 7296, Internet Key |
| * Exchange Protocol Version 2 (IKEv2)</a> |
| */ |
| public static final class EncryptionTransform extends Transform { |
| private static final int KEY_LEN_UNSPECIFIED = 0; |
| |
| // When using encryption algorithm with variable-length keys, mSpecifiedKeyLength MUST be |
| // set and a KeyLengthAttribute MUST be attached. Otherwise, mSpecifiedKeyLength MUST NOT be |
| // set and KeyLengthAttribute MUST NOT be attached. |
| private final int mSpecifiedKeyLength; |
| |
| /** |
| * Contruct an instance of EncryptionTransform with fixed key length for building an |
| * outbound packet. |
| * |
| * @param id the IKE standard Transform ID. |
| */ |
| public EncryptionTransform(@EncryptionAlgorithm int id) { |
| this(id, KEY_LEN_UNSPECIFIED); |
| } |
| |
| /** |
| * Contruct an instance of EncryptionTransform with variable key length for building an |
| * outbound packet. |
| * |
| * @param id the IKE standard Transform ID. |
| * @param specifiedKeyLength the specified key length of this encryption algorithm. |
| */ |
| public EncryptionTransform(@EncryptionAlgorithm int id, int specifiedKeyLength) { |
| super(Transform.TRANSFORM_TYPE_ENCR, id); |
| |
| mSpecifiedKeyLength = specifiedKeyLength; |
| try { |
| validateKeyLength(); |
| } catch (InvalidSyntaxException e) { |
| throw new IllegalArgumentException(e); |
| } |
| } |
| |
| /** |
| * Contruct an instance of EncryptionTransform for decoding an inbound packet. |
| * |
| * @param id the IKE standard Transform ID. |
| * @param attributeList the decoded list of Attribute. |
| * @throws InvalidSyntaxException for syntax error. |
| */ |
| protected EncryptionTransform(int id, List<Attribute> attributeList) |
| throws InvalidSyntaxException { |
| super(Transform.TRANSFORM_TYPE_ENCR, id, attributeList); |
| if (!isSupported) { |
| mSpecifiedKeyLength = KEY_LEN_UNSPECIFIED; |
| } else { |
| if (attributeList.size() == 0) { |
| mSpecifiedKeyLength = KEY_LEN_UNSPECIFIED; |
| } else { |
| KeyLengthAttribute attr = getKeyLengthAttribute(attributeList); |
| mSpecifiedKeyLength = attr.keyLength; |
| } |
| validateKeyLength(); |
| } |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(type, id, mSpecifiedKeyLength); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (!(o instanceof EncryptionTransform)) return false; |
| |
| EncryptionTransform other = (EncryptionTransform) o; |
| return (type == other.type |
| && id == other.id |
| && mSpecifiedKeyLength == other.mSpecifiedKeyLength); |
| } |
| |
| @Override |
| protected boolean isSupportedTransformId(int id) { |
| return SaProposal.isSupportedEncryptionAlgorithm(id); |
| } |
| |
| @Override |
| protected boolean hasUnrecognizedAttribute(List<Attribute> attributeList) { |
| for (Attribute attr : attributeList) { |
| if (attr instanceof UnrecognizedAttribute) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| private KeyLengthAttribute getKeyLengthAttribute(List<Attribute> attributeList) { |
| for (Attribute attr : attributeList) { |
| if (attr.type == Attribute.ATTRIBUTE_TYPE_KEY_LENGTH) { |
| return (KeyLengthAttribute) attr; |
| } |
| } |
| throw new IllegalArgumentException("Cannot find Attribute with Key Length type"); |
| } |
| |
| private void validateKeyLength() throws InvalidSyntaxException { |
| switch (id) { |
| case SaProposal.ENCRYPTION_ALGORITHM_3DES: |
| if (mSpecifiedKeyLength != KEY_LEN_UNSPECIFIED) { |
| throw new InvalidSyntaxException( |
| "Must not set Key Length value for this " |
| + getTransformTypeString() |
| + " Algorithm ID: " |
| + id); |
| } |
| return; |
| case SaProposal.ENCRYPTION_ALGORITHM_AES_CBC: |
| /* fall through */ |
| case SaProposal.ENCRYPTION_ALGORITHM_AES_GCM_8: |
| /* fall through */ |
| case SaProposal.ENCRYPTION_ALGORITHM_AES_GCM_12: |
| /* fall through */ |
| case SaProposal.ENCRYPTION_ALGORITHM_AES_GCM_16: |
| if (mSpecifiedKeyLength == KEY_LEN_UNSPECIFIED) { |
| throw new InvalidSyntaxException( |
| "Must set Key Length value for this " |
| + getTransformTypeString() |
| + " Algorithm ID: " |
| + id); |
| } |
| if (mSpecifiedKeyLength != SaProposal.KEY_LEN_AES_128 |
| && mSpecifiedKeyLength != SaProposal.KEY_LEN_AES_192 |
| && mSpecifiedKeyLength != SaProposal.KEY_LEN_AES_256) { |
| throw new InvalidSyntaxException( |
| "Invalid key length for this " |
| + getTransformTypeString() |
| + " Algorithm ID: " |
| + id); |
| } |
| return; |
| default: |
| // Won't hit here. |
| throw new IllegalArgumentException( |
| "Unrecognized Encryption Algorithm ID: " + id); |
| } |
| } |
| |
| @Override |
| protected void encodeToByteBuffer(boolean isLast, ByteBuffer byteBuffer) { |
| encodeBasicTransformToByteBuffer(isLast, byteBuffer); |
| |
| if (mSpecifiedKeyLength != KEY_LEN_UNSPECIFIED) { |
| new KeyLengthAttribute(mSpecifiedKeyLength).encodeToByteBuffer(byteBuffer); |
| } |
| } |
| |
| @Override |
| protected int getTransformLength() { |
| int len = BASIC_TRANSFORM_LEN; |
| |
| if (mSpecifiedKeyLength != KEY_LEN_UNSPECIFIED) { |
| len += new KeyLengthAttribute(mSpecifiedKeyLength).getAttributeLength(); |
| } |
| |
| return len; |
| } |
| |
| @Override |
| public String getTransformTypeString() { |
| return "Encryption Algorithm"; |
| } |
| } |
| |
| /** |
| * PrfTransform represents an pseudorandom function. |
| * |
| * @see <a href="https://tools.ietf.org/html/rfc7296#section-3.3.2">RFC 7296, Internet Key |
| * Exchange Protocol Version 2 (IKEv2)</a> |
| */ |
| public static final class PrfTransform extends Transform { |
| /** |
| * Contruct an instance of PrfTransform for building an outbound packet. |
| * |
| * @param id the IKE standard Transform ID. |
| */ |
| public PrfTransform(@PseudorandomFunction int id) { |
| super(Transform.TRANSFORM_TYPE_PRF, id); |
| } |
| |
| /** |
| * Contruct an instance of PrfTransform for decoding an inbound packet. |
| * |
| * @param id the IKE standard Transform ID. |
| * @param attributeList the decoded list of Attribute. |
| * @throws InvalidSyntaxException for syntax error. |
| */ |
| protected PrfTransform(int id, List<Attribute> attributeList) |
| throws InvalidSyntaxException { |
| super(Transform.TRANSFORM_TYPE_PRF, id, attributeList); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(type, id); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (!(o instanceof PrfTransform)) return false; |
| |
| PrfTransform other = (PrfTransform) o; |
| return (type == other.type && id == other.id); |
| } |
| |
| @Override |
| protected boolean isSupportedTransformId(int id) { |
| return SaProposal.isSupportedPseudorandomFunction(id); |
| } |
| |
| @Override |
| protected boolean hasUnrecognizedAttribute(List<Attribute> attributeList) { |
| return !attributeList.isEmpty(); |
| } |
| |
| @Override |
| protected void encodeToByteBuffer(boolean isLast, ByteBuffer byteBuffer) { |
| encodeBasicTransformToByteBuffer(isLast, byteBuffer); |
| } |
| |
| @Override |
| protected int getTransformLength() { |
| return BASIC_TRANSFORM_LEN; |
| } |
| |
| @Override |
| public String getTransformTypeString() { |
| return "Pseudorandom Function"; |
| } |
| } |
| |
| /** |
| * IntegrityTransform represents an integrity algorithm. |
| * |
| * <p>Proposing integrity algorithm for ESP SA is optional. Omitting the IntegrityTransform is |
| * equivalent to including it with a value of NONE. When multiple integrity algorithms are |
| * provided, choosing any of them are acceptable. |
| * |
| * @see <a href="https://tools.ietf.org/html/rfc7296#section-3.3.2">RFC 7296, Internet Key |
| * Exchange Protocol Version 2 (IKEv2)</a> |
| */ |
| public static final class IntegrityTransform extends Transform { |
| /** |
| * Contruct an instance of IntegrityTransform for building an outbound packet. |
| * |
| * @param id the IKE standard Transform ID. |
| */ |
| public IntegrityTransform(@IntegrityAlgorithm int id) { |
| super(Transform.TRANSFORM_TYPE_INTEG, id); |
| } |
| |
| /** |
| * Contruct an instance of IntegrityTransform for decoding an inbound packet. |
| * |
| * @param id the IKE standard Transform ID. |
| * @param attributeList the decoded list of Attribute. |
| * @throws InvalidSyntaxException for syntax error. |
| */ |
| protected IntegrityTransform(int id, List<Attribute> attributeList) |
| throws InvalidSyntaxException { |
| super(Transform.TRANSFORM_TYPE_INTEG, id, attributeList); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(type, id); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (!(o instanceof IntegrityTransform)) return false; |
| |
| IntegrityTransform other = (IntegrityTransform) o; |
| return (type == other.type && id == other.id); |
| } |
| |
| @Override |
| protected boolean isSupportedTransformId(int id) { |
| return SaProposal.isSupportedIntegrityAlgorithm(id); |
| } |
| |
| @Override |
| protected boolean hasUnrecognizedAttribute(List<Attribute> attributeList) { |
| return !attributeList.isEmpty(); |
| } |
| |
| @Override |
| protected void encodeToByteBuffer(boolean isLast, ByteBuffer byteBuffer) { |
| encodeBasicTransformToByteBuffer(isLast, byteBuffer); |
| } |
| |
| @Override |
| protected int getTransformLength() { |
| return BASIC_TRANSFORM_LEN; |
| } |
| |
| @Override |
| public String getTransformTypeString() { |
| return "Integrity Algorithm"; |
| } |
| } |
| |
| /** |
| * DhGroupTransform represents a Diffie-Hellman Group |
| * |
| * <p>Proposing DH group for non-first Child SA is optional. Omitting the DhGroupTransform is |
| * equivalent to including it with a value of NONE. When multiple DH groups are provided, |
| * choosing any of them are acceptable. |
| * |
| * @see <a href="https://tools.ietf.org/html/rfc7296#section-3.3.2">RFC 7296, Internet Key |
| * Exchange Protocol Version 2 (IKEv2)</a> |
| */ |
| public static final class DhGroupTransform extends Transform { |
| /** |
| * Contruct an instance of DhGroupTransform for building an outbound packet. |
| * |
| * @param id the IKE standard Transform ID. |
| */ |
| public DhGroupTransform(@DhGroup int id) { |
| super(Transform.TRANSFORM_TYPE_DH, id); |
| } |
| |
| /** |
| * Contruct an instance of DhGroupTransform for decoding an inbound packet. |
| * |
| * @param id the IKE standard Transform ID. |
| * @param attributeList the decoded list of Attribute. |
| * @throws InvalidSyntaxException for syntax error. |
| */ |
| protected DhGroupTransform(int id, List<Attribute> attributeList) |
| throws InvalidSyntaxException { |
| super(Transform.TRANSFORM_TYPE_DH, id, attributeList); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(type, id); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (!(o instanceof DhGroupTransform)) return false; |
| |
| DhGroupTransform other = (DhGroupTransform) o; |
| return (type == other.type && id == other.id); |
| } |
| |
| @Override |
| protected boolean isSupportedTransformId(int id) { |
| return SaProposal.isSupportedDhGroup(id); |
| } |
| |
| @Override |
| protected boolean hasUnrecognizedAttribute(List<Attribute> attributeList) { |
| return !attributeList.isEmpty(); |
| } |
| |
| @Override |
| protected void encodeToByteBuffer(boolean isLast, ByteBuffer byteBuffer) { |
| encodeBasicTransformToByteBuffer(isLast, byteBuffer); |
| } |
| |
| @Override |
| protected int getTransformLength() { |
| return BASIC_TRANSFORM_LEN; |
| } |
| |
| @Override |
| public String getTransformTypeString() { |
| return "Diffie-Hellman Group"; |
| } |
| } |
| |
| /** |
| * EsnTransform represents ESN policy that indicates if IPsec SA uses tranditional 32-bit |
| * sequence numbers or extended(64-bit) sequence numbers. |
| * |
| * <p>Currently IKE library only supports negotiating IPsec SA that do not use extended sequence |
| * numbers. The Transform ID of EsnTransform in outbound packets is not user configurable. |
| * |
| * @see <a href="https://tools.ietf.org/html/rfc7296#section-3.3.2">RFC 7296, Internet Key |
| * Exchange Protocol Version 2 (IKEv2)</a> |
| */ |
| public static final class EsnTransform extends Transform { |
| @Retention(RetentionPolicy.SOURCE) |
| @IntDef({ESN_POLICY_NO_EXTENDED, ESN_POLICY_EXTENDED}) |
| public @interface EsnPolicy {} |
| |
| public static final int ESN_POLICY_NO_EXTENDED = 0; |
| public static final int ESN_POLICY_EXTENDED = 1; |
| |
| /** |
| * Construct an instance of EsnTransform indicates using no-extended sequence numbers for |
| * building an outbound packet. |
| */ |
| public EsnTransform() { |
| super(Transform.TRANSFORM_TYPE_ESN, ESN_POLICY_NO_EXTENDED); |
| } |
| |
| /** |
| * Contruct an instance of EsnTransform for decoding an inbound packet. |
| * |
| * @param id the IKE standard Transform ID. |
| * @param attributeList the decoded list of Attribute. |
| * @throws InvalidSyntaxException for syntax error. |
| */ |
| protected EsnTransform(int id, List<Attribute> attributeList) |
| throws InvalidSyntaxException { |
| super(Transform.TRANSFORM_TYPE_ESN, id, attributeList); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(type, id); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (!(o instanceof EsnTransform)) return false; |
| |
| EsnTransform other = (EsnTransform) o; |
| return (type == other.type && id == other.id); |
| } |
| |
| @Override |
| protected boolean isSupportedTransformId(int id) { |
| return (id == ESN_POLICY_NO_EXTENDED || id == ESN_POLICY_EXTENDED); |
| } |
| |
| @Override |
| protected boolean hasUnrecognizedAttribute(List<Attribute> attributeList) { |
| return !attributeList.isEmpty(); |
| } |
| |
| @Override |
| protected void encodeToByteBuffer(boolean isLast, ByteBuffer byteBuffer) { |
| encodeBasicTransformToByteBuffer(isLast, byteBuffer); |
| } |
| |
| @Override |
| protected int getTransformLength() { |
| return BASIC_TRANSFORM_LEN; |
| } |
| |
| @Override |
| public String getTransformTypeString() { |
| return "Extended Sequence Numbers"; |
| } |
| } |
| |
| /** |
| * UnrecognizedTransform represents a Transform with unrecognized Transform Type. |
| * |
| * <p>Proposals containing an UnrecognizedTransform should be ignored. |
| */ |
| protected static final class UnrecognizedTransform extends Transform { |
| protected UnrecognizedTransform(int type, int id, List<Attribute> attributeList) { |
| super(type, id, attributeList); |
| } |
| |
| @Override |
| protected boolean isSupportedTransformId(int id) { |
| return false; |
| } |
| |
| @Override |
| protected boolean hasUnrecognizedAttribute(List<Attribute> attributeList) { |
| return !attributeList.isEmpty(); |
| } |
| |
| @Override |
| protected void encodeToByteBuffer(boolean isLast, ByteBuffer byteBuffer) { |
| throw new UnsupportedOperationException( |
| "It is not supported to encode a Transform with" + getTransformTypeString()); |
| } |
| |
| @Override |
| protected int getTransformLength() { |
| throw new UnsupportedOperationException( |
| "It is not supported to get length of a Transform with " |
| + getTransformTypeString()); |
| } |
| |
| /** |
| * Return Tranform Type of Unrecognized Transform as a String. |
| * |
| * @return Tranform Type of Unrecognized Transform as a String. |
| */ |
| @Override |
| public String getTransformTypeString() { |
| return "Unrecognized Transform Type."; |
| } |
| } |
| |
| /** |
| * Attribute is an abtract base class for completing the specification of some {@link |
| * Transform}. |
| * |
| * <p>Attribute is either in Type/Value format or Type/Length/Value format. For TV format, |
| * Attribute length is always 4 bytes containing value for 2 bytes. While for TLV format, |
| * Attribute length is determined by length field. |
| * |
| * <p>Currently only Key Length type is supported |
| * |
| * @see <a href="https://tools.ietf.org/html/rfc7296#section-3.3.5">RFC 7296, Internet Key |
| * Exchange Protocol Version 2 (IKEv2)</a> |
| */ |
| public abstract static class Attribute { |
| @Retention(RetentionPolicy.SOURCE) |
| @IntDef({ATTRIBUTE_TYPE_KEY_LENGTH}) |
| public @interface AttributeType {} |
| |
| // Support only one Attribute type: Key Length. Should use Type/Value format. |
| public static final int ATTRIBUTE_TYPE_KEY_LENGTH = 14; |
| |
| // Mask to extract the left most AF bit to indicate Attribute Format. |
| private static final int ATTRIBUTE_FORMAT_MASK = 0x8000; |
| // Mask to extract 15 bits after the AF bit to indicate Attribute Type. |
| private static final int ATTRIBUTE_TYPE_MASK = 0x7fff; |
| |
| // Package private mask to indicate that Type-Value (TV) Attribute Format is used. |
| static final int ATTRIBUTE_FORMAT_TV = ATTRIBUTE_FORMAT_MASK; |
| |
| // Package private |
| static final int TV_ATTRIBUTE_VALUE_LEN = 2; |
| static final int TV_ATTRIBUTE_TOTAL_LEN = 4; |
| static final int TVL_ATTRIBUTE_HEADER_LEN = TV_ATTRIBUTE_TOTAL_LEN; |
| |
| // Only Key Length type belongs to AttributeType |
| public final int type; |
| |
| /** Construct an instance of an Attribute when decoding message. */ |
| protected Attribute(int type) { |
| this.type = type; |
| } |
| |
| @VisibleForTesting |
| static Pair<Attribute, Integer> readFrom(ByteBuffer inputBuffer) throws IkeException { |
| short formatAndType = inputBuffer.getShort(); |
| int format = formatAndType & ATTRIBUTE_FORMAT_MASK; |
| int type = formatAndType & ATTRIBUTE_TYPE_MASK; |
| |
| int length = 0; |
| byte[] value = new byte[0]; |
| if (format == ATTRIBUTE_FORMAT_TV) { |
| // Type/Value format |
| length = TV_ATTRIBUTE_TOTAL_LEN; |
| value = new byte[TV_ATTRIBUTE_VALUE_LEN]; |
| } else { |
| // Type/Length/Value format |
| if (type == ATTRIBUTE_TYPE_KEY_LENGTH) { |
| throw new InvalidSyntaxException("Wrong format in Transform Attribute"); |
| } |
| |
| length = Short.toUnsignedInt(inputBuffer.getShort()); |
| int valueLen = length - TVL_ATTRIBUTE_HEADER_LEN; |
| // IkeMessage will catch exception if valueLen is negative. |
| value = new byte[valueLen]; |
| } |
| |
| inputBuffer.get(value); |
| |
| switch (type) { |
| case ATTRIBUTE_TYPE_KEY_LENGTH: |
| return new Pair(new KeyLengthAttribute(value), length); |
| default: |
| return new Pair(new UnrecognizedAttribute(type, value), length); |
| } |
| } |
| |
| // Encode Attribute to a ByteBuffer. |
| protected abstract void encodeToByteBuffer(ByteBuffer byteBuffer); |
| |
| // Get entire Attribute length. |
| protected abstract int getAttributeLength(); |
| } |
| |
| /** KeyLengthAttribute represents a Key Length type Attribute */ |
| public static final class KeyLengthAttribute extends Attribute { |
| public final int keyLength; |
| |
| protected KeyLengthAttribute(byte[] value) { |
| this(Short.toUnsignedInt(ByteBuffer.wrap(value).getShort())); |
| } |
| |
| protected KeyLengthAttribute(int keyLength) { |
| super(ATTRIBUTE_TYPE_KEY_LENGTH); |
| this.keyLength = keyLength; |
| } |
| |
| @Override |
| protected void encodeToByteBuffer(ByteBuffer byteBuffer) { |
| byteBuffer |
| .putShort((short) (ATTRIBUTE_FORMAT_TV | ATTRIBUTE_TYPE_KEY_LENGTH)) |
| .putShort((short) keyLength); |
| } |
| |
| @Override |
| protected int getAttributeLength() { |
| return TV_ATTRIBUTE_TOTAL_LEN; |
| } |
| } |
| |
| /** |
| * UnrecognizedAttribute represents a Attribute with unrecoginzed Attribute Type. |
| * |
| * <p>Transforms containing UnrecognizedAttribute should be ignored. |
| */ |
| protected static final class UnrecognizedAttribute extends Attribute { |
| protected UnrecognizedAttribute(int type, byte[] value) { |
| super(type); |
| } |
| |
| @Override |
| protected void encodeToByteBuffer(ByteBuffer byteBuffer) { |
| throw new UnsupportedOperationException( |
| "It is not supported to encode an unrecognized Attribute."); |
| } |
| |
| @Override |
| protected int getAttributeLength() { |
| throw new UnsupportedOperationException( |
| "It is not supported to get length of an unrecognized Attribute."); |
| } |
| } |
| |
| /** |
| * Encode SA payload to ByteBUffer. |
| * |
| * @param nextPayload type of payload that follows this payload. |
| * @param byteBuffer destination ByteBuffer that stores encoded payload. |
| */ |
| @Override |
| protected void encodeToByteBuffer(@PayloadType int nextPayload, ByteBuffer byteBuffer) { |
| encodePayloadHeaderToByteBuffer(nextPayload, getPayloadLength(), byteBuffer); |
| |
| for (int i = 0; i < proposalList.size(); i++) { |
| // The last proposal has the isLast flag set to true. |
| proposalList.get(i).encodeToByteBuffer(i == proposalList.size() - 1, byteBuffer); |
| } |
| } |
| |
| /** |
| * Get entire payload length. |
| * |
| * @return entire payload length. |
| */ |
| @Override |
| protected int getPayloadLength() { |
| int len = GENERIC_HEADER_LENGTH; |
| |
| for (Proposal p : proposalList) len += p.getProposalLength(); |
| |
| return len; |
| } |
| |
| /** |
| * Return the payload type as a String. |
| * |
| * @return the payload type as a String. |
| */ |
| @Override |
| public String getTypeString() { |
| return "SA Payload"; |
| } |
| } |
