| // Copyright 2017 Google Inc. |
| // |
| // 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.google.crypto.tink.aead; |
| |
| import com.google.crypto.tink.Aead; |
| import com.google.crypto.tink.KeyTemplate; |
| import com.google.crypto.tink.Mac; |
| import com.google.crypto.tink.Registry; |
| import com.google.crypto.tink.config.internal.TinkFipsUtil; |
| import com.google.crypto.tink.internal.KeyTypeManager; |
| import com.google.crypto.tink.internal.PrimitiveFactory; |
| import com.google.crypto.tink.mac.HmacKeyManager; |
| import com.google.crypto.tink.proto.AesCtrHmacAeadKey; |
| import com.google.crypto.tink.proto.AesCtrHmacAeadKeyFormat; |
| import com.google.crypto.tink.proto.AesCtrKey; |
| import com.google.crypto.tink.proto.AesCtrKeyFormat; |
| import com.google.crypto.tink.proto.AesCtrParams; |
| import com.google.crypto.tink.proto.HashType; |
| import com.google.crypto.tink.proto.HmacKey; |
| import com.google.crypto.tink.proto.HmacKeyFormat; |
| import com.google.crypto.tink.proto.HmacParams; |
| import com.google.crypto.tink.proto.KeyData.KeyMaterialType; |
| import com.google.crypto.tink.subtle.EncryptThenAuthenticate; |
| import com.google.crypto.tink.subtle.IndCpaCipher; |
| import com.google.crypto.tink.subtle.Validators; |
| import com.google.protobuf.ByteString; |
| import com.google.protobuf.ExtensionRegistryLite; |
| import com.google.protobuf.InvalidProtocolBufferException; |
| import java.security.GeneralSecurityException; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| /** |
| * This key manager generates new {@link AesCtrHmacAeadKey} keys and produces new instances of |
| * {@link EncryptThenAuthenticate}. |
| */ |
| public final class AesCtrHmacAeadKeyManager extends KeyTypeManager<AesCtrHmacAeadKey> { |
| AesCtrHmacAeadKeyManager() { |
| super( |
| AesCtrHmacAeadKey.class, |
| new PrimitiveFactory<Aead, AesCtrHmacAeadKey>(Aead.class) { |
| @Override |
| public Aead getPrimitive(AesCtrHmacAeadKey key) throws GeneralSecurityException { |
| return new EncryptThenAuthenticate( |
| new AesCtrKeyManager().getPrimitive(key.getAesCtrKey(), IndCpaCipher.class), |
| new HmacKeyManager().getPrimitive(key.getHmacKey(), Mac.class), |
| key.getHmacKey().getParams().getTagSize()); |
| } |
| }); |
| } |
| |
| // Static so we don't have to construct the object and handle the exception when we need the |
| // key type. |
| @Override |
| public String getKeyType() { |
| return "type.googleapis.com/google.crypto.tink.AesCtrHmacAeadKey"; |
| } |
| |
| @Override |
| public int getVersion() { |
| return 0; |
| } |
| |
| @Override |
| public KeyMaterialType keyMaterialType() { |
| return KeyMaterialType.SYMMETRIC; |
| } |
| |
| @Override |
| public void validateKey(AesCtrHmacAeadKey key) throws GeneralSecurityException { |
| Validators.validateVersion(key.getVersion(), getVersion()); |
| new AesCtrKeyManager().validateKey(key.getAesCtrKey()); |
| new HmacKeyManager().validateKey(key.getHmacKey()); |
| } |
| |
| @Override |
| public AesCtrHmacAeadKey parseKey(ByteString byteString) throws InvalidProtocolBufferException { |
| return AesCtrHmacAeadKey.parseFrom(byteString, ExtensionRegistryLite.getEmptyRegistry()); |
| } |
| |
| @Override |
| public KeyFactory<AesCtrHmacAeadKeyFormat, AesCtrHmacAeadKey> keyFactory() { |
| return new KeyFactory<AesCtrHmacAeadKeyFormat, AesCtrHmacAeadKey>( |
| AesCtrHmacAeadKeyFormat.class) { |
| @Override |
| public void validateKeyFormat(AesCtrHmacAeadKeyFormat format) |
| throws GeneralSecurityException { |
| new AesCtrKeyManager().keyFactory().validateKeyFormat(format.getAesCtrKeyFormat()); |
| new HmacKeyManager().keyFactory().validateKeyFormat(format.getHmacKeyFormat()); |
| Validators.validateAesKeySize(format.getAesCtrKeyFormat().getKeySize()); |
| } |
| |
| @Override |
| public AesCtrHmacAeadKeyFormat parseKeyFormat(ByteString byteString) |
| throws InvalidProtocolBufferException { |
| return AesCtrHmacAeadKeyFormat.parseFrom( |
| byteString, ExtensionRegistryLite.getEmptyRegistry()); |
| } |
| |
| @Override |
| public AesCtrHmacAeadKey createKey(AesCtrHmacAeadKeyFormat format) |
| throws GeneralSecurityException { |
| AesCtrKey aesCtrKey = |
| new AesCtrKeyManager().keyFactory().createKey(format.getAesCtrKeyFormat()); |
| HmacKey hmacKey = new HmacKeyManager().keyFactory().createKey(format.getHmacKeyFormat()); |
| return AesCtrHmacAeadKey.newBuilder() |
| .setAesCtrKey(aesCtrKey) |
| .setHmacKey(hmacKey) |
| .setVersion(getVersion()) |
| .build(); |
| } |
| |
| @Override |
| public Map<String, KeyFactory.KeyFormat<AesCtrHmacAeadKeyFormat>> keyFormats() |
| throws GeneralSecurityException { |
| Map<String, KeyFactory.KeyFormat<AesCtrHmacAeadKeyFormat>> result = new HashMap<>(); |
| |
| result.put( |
| "AES128_CTR_HMAC_SHA256", |
| createKeyFormat(16, 16, 32, 16, HashType.SHA256, KeyTemplate.OutputPrefixType.TINK)); |
| result.put( |
| "AES128_CTR_HMAC_SHA256_RAW", |
| createKeyFormat(16, 16, 32, 16, HashType.SHA256, KeyTemplate.OutputPrefixType.RAW)); |
| |
| result.put( |
| "AES256_CTR_HMAC_SHA256", |
| createKeyFormat(32, 16, 32, 32, HashType.SHA256, KeyTemplate.OutputPrefixType.TINK)); |
| result.put( |
| "AES256_CTR_HMAC_SHA256_RAW", |
| createKeyFormat(32, 16, 32, 32, HashType.SHA256, KeyTemplate.OutputPrefixType.RAW)); |
| |
| return Collections.unmodifiableMap(result); |
| } |
| }; |
| } |
| |
| public static void register(boolean newKeyAllowed) throws GeneralSecurityException { |
| Registry.registerKeyManager(new AesCtrHmacAeadKeyManager(), newKeyAllowed); |
| } |
| |
| /** |
| * @return a {@link KeyTemplate} that generates new instances of AES-CTR-HMAC-AEAD keys with the |
| * following parameters: |
| * <ul> |
| * <li>AES key size: 16 bytes |
| * <li>AES CTR IV size: 16 byte |
| * <li>HMAC key size: 32 bytes |
| * <li>HMAC tag size: 16 bytes |
| * <li>HMAC hash function: SHA256 |
| * </ul> |
| * |
| * @deprecated use {@code KeyTemplates.get("AES128_CTR_HMAC_SHA256")} |
| */ |
| @Deprecated |
| public static final KeyTemplate aes128CtrHmacSha256Template() { |
| return createKeyTemplate(16, 16, 32, 16, HashType.SHA256); |
| } |
| |
| /** |
| * @return a {@link KeyTemplate} that generates new instances of AES-CTR-HMAC-AEAD keys with the |
| * following parameters: |
| * <ul> |
| * <li>AES key size: 32 bytes |
| * <li>AES CTR IV size: 16 byte |
| * <li>HMAC key size: 32 bytes |
| * <li>HMAC tag size: 32 bytes |
| * <li>HMAC hash function: SHA256 |
| * </ul> |
| * |
| * @deprecated use {@code KeyTemplates.get("AES256_CTR_HMAC_SHA256")} |
| */ |
| @Deprecated |
| public static final KeyTemplate aes256CtrHmacSha256Template() { |
| return createKeyTemplate(32, 16, 32, 32, HashType.SHA256); |
| } |
| |
| /** |
| * @return a {@link KeyTemplate} containing a {@link AesCtrHmacAeadKeyFormat} with some specific |
| * parameters. |
| */ |
| private static KeyTemplate createKeyTemplate( |
| int aesKeySize, int ivSize, int hmacKeySize, int tagSize, HashType hashType) { |
| AesCtrHmacAeadKeyFormat format = |
| createKeyFormat(aesKeySize, ivSize, hmacKeySize, tagSize, hashType); |
| return KeyTemplate.create( |
| new AesCtrHmacAeadKeyManager().getKeyType(), |
| format.toByteArray(), |
| KeyTemplate.OutputPrefixType.TINK); |
| } |
| |
| private static KeyFactory.KeyFormat<AesCtrHmacAeadKeyFormat> createKeyFormat( |
| int aesKeySize, |
| int ivSize, |
| int hmacKeySize, |
| int tagSize, |
| HashType hashType, |
| KeyTemplate.OutputPrefixType prefixType) { |
| return new KeyFactory.KeyFormat<>( |
| createKeyFormat(aesKeySize, ivSize, hmacKeySize, tagSize, hashType), prefixType); |
| } |
| |
| private static AesCtrHmacAeadKeyFormat createKeyFormat( |
| int aesKeySize, int ivSize, int hmacKeySize, int tagSize, HashType hashType) { |
| AesCtrKeyFormat aesCtrKeyFormat = |
| AesCtrKeyFormat.newBuilder() |
| .setParams(AesCtrParams.newBuilder().setIvSize(ivSize).build()) |
| .setKeySize(aesKeySize) |
| .build(); |
| HmacKeyFormat hmacKeyFormat = |
| HmacKeyFormat.newBuilder() |
| .setParams(HmacParams.newBuilder().setHash(hashType).setTagSize(tagSize).build()) |
| .setKeySize(hmacKeySize) |
| .build(); |
| return AesCtrHmacAeadKeyFormat.newBuilder() |
| .setAesCtrKeyFormat(aesCtrKeyFormat) |
| .setHmacKeyFormat(hmacKeyFormat) |
| .build(); |
| } |
| |
| @Override |
| public TinkFipsUtil.AlgorithmFipsCompatibility fipsStatus() { |
| return TinkFipsUtil.AlgorithmFipsCompatibility.ALGORITHM_REQUIRES_BORINGCRYPTO; |
| }; |
| } |
