1 // Copyright 2023 Google Inc. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 // 15 //////////////////////////////////////////////////////////////////////////////// 16 17 package com.google.crypto.tink.hybrid; 18 19 import static com.google.crypto.tink.internal.TinkBugException.exceptionIsBug; 20 21 import com.google.crypto.tink.aead.AesCtrHmacAeadParameters; 22 import com.google.crypto.tink.aead.AesGcmParameters; 23 24 /** 25 * Pre-generated {@link Parameter} objects for {@link com.google.crypto.tink.HybridEncrypt} and 26 * {@link com.google.crypto.tink.HybridDecrypt} keys. 27 * 28 * <p>Note: if you want to keep dependencies small, consider inlining the constants here. 29 */ 30 public final class PredefinedHybridParameters { 31 /** 32 * A {@link KeyTemplate} that generates new instances of {@link 33 * com.google.crypto.tink.proto.EciesAeadHkdfPrivateKey} with the following parameters: 34 * 35 * <ul> 36 * <li>KEM: ECDH over NIST P-256 37 * <li>DEM: AES128-GCM 38 * <li>KDF: HKDF-HMAC-SHA256 with an empty salt 39 * </ul> 40 * 41 * <p>Unlike other key templates that use AES-GCM, the instances of {@link HybridDecrypt} 42 * generated by this key template has no limitation on Android KitKat (API level 19). They might 43 * not work in older versions though. 44 */ 45 public static final EciesParameters ECIES_P256_HKDF_HMAC_SHA256_AES128_GCM = 46 exceptionIsBug( 47 () -> 48 EciesParameters.builder() 49 .setCurveType(EciesParameters.CurveType.NIST_P256) 50 .setHashType(EciesParameters.HashType.SHA256) 51 .setNistCurvePointFormat(EciesParameters.PointFormat.UNCOMPRESSED) 52 .setVariant(EciesParameters.Variant.TINK) 53 .setDemParameters( 54 AesGcmParameters.builder() 55 .setIvSizeBytes(12) 56 .setKeySizeBytes(16) 57 .setTagSizeBytes(16) 58 .setVariant(AesGcmParameters.Variant.NO_PREFIX) 59 .build()) 60 .build()); 61 62 /** 63 * A {@link KeyTemplate} that generates new instances of {@link 64 * com.google.crypto.tink.proto.EciesAeadHkdfPrivateKey} with the following parameters: 65 * 66 * <ul> 67 * <li>KEM: ECDH over NIST P-256 68 * <li>DEM: AES128-GCM 69 * <li>KDF: HKDF-HMAC-SHA256 with an empty salt 70 * <li>EC Point Format: Compressed 71 * <li>OutputPrefixType: RAW 72 * </ul> 73 * 74 * <p>Unlike other key templates that use AES-GCM, the instances of {@link HybridDecrypt} 75 * generated by this key template has no limitation on Android KitKat (API level 19). They might 76 * not work in older versions though. 77 */ 78 public static final EciesParameters 79 ECIES_P256_HKDF_HMAC_SHA256_AES128_GCM_COMPRESSED_WITHOUT_PREFIX = 80 exceptionIsBug( 81 () -> 82 EciesParameters.builder() 83 .setCurveType(EciesParameters.CurveType.NIST_P256) 84 .setHashType(EciesParameters.HashType.SHA256) 85 .setNistCurvePointFormat(EciesParameters.PointFormat.COMPRESSED) 86 .setVariant(EciesParameters.Variant.NO_PREFIX) 87 .setDemParameters( 88 AesGcmParameters.builder() 89 .setIvSizeBytes(12) 90 .setKeySizeBytes(16) 91 .setTagSizeBytes(16) 92 .setVariant(AesGcmParameters.Variant.NO_PREFIX) 93 .build()) 94 .build()); 95 96 /** 97 * A {@link KeyTemplate} that generates new instances of {@link 98 * com.google.crypto.tink.proto.EciesAeadHkdfPrivateKey} with the following parameters: 99 * 100 * <ul> 101 * <li>KEM: ECDH over NIST P-256 102 * <li>DEM: AES128-CTR-HMAC-SHA256 with the following parameters 103 * <ul> 104 * <li>AES key size: 16 bytes 105 * <li>AES CTR IV size: 16 bytes 106 * <li>HMAC key size: 32 bytes 107 * <li>HMAC tag size: 16 bytes 108 * </ul> 109 * <li>KDF: HKDF-HMAC-SHA256 with an empty salt 110 * </ul> 111 */ 112 public static final EciesParameters ECIES_P256_HKDF_HMAC_SHA256_AES128_CTR_HMAC_SHA256 = 113 exceptionIsBug( 114 () -> 115 EciesParameters.builder() 116 .setCurveType(EciesParameters.CurveType.NIST_P256) 117 .setHashType(EciesParameters.HashType.SHA256) 118 .setNistCurvePointFormat(EciesParameters.PointFormat.UNCOMPRESSED) 119 .setVariant(EciesParameters.Variant.TINK) 120 .setDemParameters( 121 AesCtrHmacAeadParameters.builder() 122 .setAesKeySizeBytes(16) 123 .setHmacKeySizeBytes(32) 124 .setTagSizeBytes(16) 125 .setIvSizeBytes(16) 126 .setHashType(AesCtrHmacAeadParameters.HashType.SHA256) 127 .setVariant(AesCtrHmacAeadParameters.Variant.NO_PREFIX) 128 .build()) 129 .build()); 130 PredefinedHybridParameters()131 private PredefinedHybridParameters() {} 132 } 133