| /* |
| * Copyright(C) 2021 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" (short)0IS, |
| * 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.javacard.keymaster; |
| |
| import javacard.framework.ISO7816; |
| import javacard.framework.ISOException; |
| import javacard.framework.Util; |
| |
| /** |
| * KMCoseHeaders represents headers section from the Cose standard |
| * https://datatracker.ietf.org/doc/html/rfc8152#section-3. The supported key types are KMInteger, |
| * KMNInteger and the supported value types are KMInteger, KMNInteger, KMByteBlob, KMCoseKey. It |
| * corresponds to a CBOR Map type. struct{byte TAG_TYPE; short length; short arrayPtr } where |
| * arrayPtr is a pointer to array with any KMTag subtype instances. |
| */ |
| public class KMCoseHeaders extends KMCoseMap { |
| |
| private static KMCoseHeaders prototype; |
| |
| private KMCoseHeaders() {} |
| |
| private static KMCoseHeaders proto(short ptr) { |
| if (prototype == null) { |
| prototype = new KMCoseHeaders(); |
| } |
| instanceTable[KM_COSE_HEADERS_OFFSET] = ptr; |
| return prototype; |
| } |
| |
| public static short exp() { |
| short arrPtr = KMArray.instance((short) 4); |
| // CoseKey is internally an Array so evaluate it separately. |
| short coseKeyValueExp = KMCosePairCoseKeyTag.exp(); |
| KMArray arr = KMArray.cast(arrPtr); |
| arr.add((short) 0, KMCosePairIntegerTag.exp()); |
| arr.add((short) 1, KMCosePairNegIntegerTag.exp()); |
| arr.add((short) 2, KMCosePairByteBlobTag.exp()); |
| arr.add((short) 3, coseKeyValueExp); |
| return KMCoseHeaders.instance(arrPtr); |
| } |
| |
| public static short instance(short vals) { |
| short ptr = KMType.instance(COSE_HEADERS_TYPE, (short) 2); |
| Util.setShort(heap, (short) (ptr + TLV_HEADER_SIZE), vals); |
| return ptr; |
| } |
| |
| public static KMCoseHeaders cast(short ptr) { |
| if (heap[ptr] != COSE_HEADERS_TYPE) { |
| ISOException.throwIt(ISO7816.SW_CONDITIONS_NOT_SATISFIED); |
| } |
| short arrPtr = Util.getShort(heap, (short) (ptr + TLV_HEADER_SIZE)); |
| if (heap[arrPtr] != ARRAY_TYPE) { |
| ISOException.throwIt(ISO7816.SW_CONDITIONS_NOT_SATISFIED); |
| } |
| return proto(ptr); |
| } |
| |
| @Override |
| public short getVals() { |
| return Util.getShort(heap, (short) (instanceTable[KM_COSE_HEADERS_OFFSET] + TLV_HEADER_SIZE)); |
| } |
| |
| @Override |
| public short length() { |
| short arrPtr = getVals(); |
| return KMArray.cast(arrPtr).length(); |
| } |
| |
| @Override |
| public void canonicalize() { |
| KMCoseMap.canonicalize(getVals()); |
| } |
| |
| private short getValueType(short key) { |
| short index = 0; |
| short len = length(); |
| short arr = getVals(); |
| short tagType; |
| short valPtr = 0; |
| short keyPtr; |
| boolean found = false; |
| while (index < len) { |
| tagType = KMCosePairTagType.getTagValueType(KMArray.cast(arr).get(index)); |
| switch (tagType) { |
| case KMType.COSE_PAIR_BYTE_BLOB_TAG_TYPE: |
| keyPtr = KMCosePairByteBlobTag.cast(KMArray.cast(arr).get(index)).getKeyPtr(); |
| if (key == (byte) KMCosePairTagType.getKeyValueShort(keyPtr)) { |
| valPtr = KMCosePairByteBlobTag.cast(KMArray.cast(arr).get(index)).getValuePtr(); |
| found = true; |
| } |
| break; |
| case KMType.COSE_PAIR_COSE_KEY_TAG_TYPE: |
| keyPtr = KMCosePairCoseKeyTag.cast(KMArray.cast(arr).get(index)).getKeyPtr(); |
| if (key == (byte) KMCosePairTagType.getKeyValueShort(keyPtr)) { |
| valPtr = KMCosePairCoseKeyTag.cast(KMArray.cast(arr).get(index)).getValuePtr(); |
| found = true; |
| } |
| break; |
| case KMType.COSE_PAIR_INT_TAG_TYPE: |
| keyPtr = KMCosePairIntegerTag.cast(KMArray.cast(arr).get(index)).getKeyPtr(); |
| if (key == (byte) KMCosePairTagType.getKeyValueShort(keyPtr)) { |
| valPtr = KMCosePairIntegerTag.cast(KMArray.cast(arr).get(index)).getValuePtr(); |
| found = true; |
| } |
| break; |
| case KMType.COSE_PAIR_NEG_INT_TAG_TYPE: |
| keyPtr = KMCosePairNegIntegerTag.cast(KMArray.cast(arr).get(index)).getKeyPtr(); |
| if (key == (byte) KMCosePairTagType.getKeyValueShort(keyPtr)) { |
| valPtr = KMCosePairNegIntegerTag.cast(KMArray.cast(arr).get(index)).getValuePtr(); |
| found = true; |
| } |
| break; |
| default: |
| break; |
| } |
| if (found) { |
| break; |
| } |
| index++; |
| } |
| return valPtr; |
| } |
| |
| public short getKeyIdentifier() { |
| return getValueType(KMCose.COSE_LABEL_KEYID); |
| } |
| |
| public short getCoseKey() { |
| return getValueType(KMCose.COSE_LABEL_COSE_KEY); |
| } |
| |
| public short getIV() { |
| return getValueType(KMCose.COSE_LABEL_IV); |
| } |
| |
| public short getAlgorithm() { |
| return getValueType(KMCose.COSE_LABEL_ALGORITHM); |
| } |
| |
| public boolean isDataValid(short[] buff, short alg, short keyIdPtr) { |
| short bufLen = 4; |
| buff[0] = KMCose.COSE_LABEL_ALGORITHM; |
| buff[1] = alg; |
| buff[2] = KMCose.COSE_LABEL_KEYID; |
| buff[3] = keyIdPtr; |
| boolean valid = false; |
| short value; |
| short ptr; |
| short tagIndex = 0; |
| while (tagIndex < bufLen) { |
| value = buff[(short) (tagIndex + 1)]; |
| if (value != KMType.INVALID_VALUE) { |
| valid = false; |
| ptr = getValueType(buff[tagIndex]); |
| switch (KMType.getType(ptr)) { |
| case KMType.BYTE_BLOB_TYPE: |
| if ((KMByteBlob.cast(value).length() == KMByteBlob.cast(ptr).length()) |
| && (0 |
| == Util.arrayCompare( |
| KMByteBlob.cast(value).getBuffer(), |
| KMByteBlob.cast(value).getStartOff(), |
| KMByteBlob.cast(ptr).getBuffer(), |
| KMByteBlob.cast(ptr).getStartOff(), |
| KMByteBlob.cast(ptr).length()))) { |
| valid = true; |
| } |
| break; |
| case KMType.INTEGER_TYPE: |
| if (value == KMInteger.cast(ptr).getShort()) { |
| valid = true; |
| } |
| break; |
| case KMType.NEG_INTEGER_TYPE: |
| if ((byte) value == (byte) KMNInteger.cast(ptr).getShort()) { |
| valid = true; |
| } |
| break; |
| default: |
| break; |
| } |
| if (!valid) { |
| break; |
| } |
| } |
| tagIndex += 2; |
| } |
| return valid; |
| } |
| } |