1 /* 2 * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.security.spec; 27 28 import java.security.spec.AlgorithmParameterSpec; 29 30 /** 31 * This class specifies the set of parameters used with mask generation 32 * function MGF1 in OAEP Padding and RSASSA-PSS signature scheme, as 33 * defined in the 34 * <a href="https://tools.ietf.org/rfc/rfc8017.txt">PKCS#1 v2.2</a> standard. 35 * 36 * <p>Its ASN.1 definition in PKCS#1 standard is described below: 37 * <pre> 38 * PKCS1MGFAlgorithms ALGORITHM-IDENTIFIER ::= { 39 * { OID id-mgf1 PARAMETERS HashAlgorithm }, 40 * ... -- Allows for future expansion -- 41 * } 42 * </pre> 43 * where 44 * <pre> 45 * HashAlgorithm ::= AlgorithmIdentifier { 46 * {OAEP-PSSDigestAlgorithms} 47 * } 48 * 49 * OAEP-PSSDigestAlgorithms ALGORITHM-IDENTIFIER ::= { 50 * { OID id-sha1 PARAMETERS NULL }| 51 * { OID id-sha224 PARAMETERS NULL }| 52 * { OID id-sha256 PARAMETERS NULL }| 53 * { OID id-sha384 PARAMETERS NULL }| 54 * { OID id-sha512 PARAMETERS NULL }| 55 * { OID id-sha512-224 PARAMETERS NULL }| 56 * { OID id-sha512-256 PARAMETERS NULL }, 57 * ... -- Allows for future expansion -- 58 * } 59 * </pre> 60 * @see PSSParameterSpec 61 * @see javax.crypto.spec.OAEPParameterSpec 62 * 63 * @author Valerie Peng 64 * 65 * @since 1.5 66 */ 67 public class MGF1ParameterSpec implements AlgorithmParameterSpec { 68 69 /** 70 * The MGF1ParameterSpec which uses "SHA-1" message digest 71 */ 72 public static final MGF1ParameterSpec SHA1 = 73 new MGF1ParameterSpec("SHA-1"); 74 75 /** 76 * The MGF1ParameterSpec which uses "SHA-224" message digest 77 */ 78 public static final MGF1ParameterSpec SHA224 = 79 new MGF1ParameterSpec("SHA-224"); 80 81 /** 82 * The MGF1ParameterSpec which uses "SHA-256" message digest 83 */ 84 public static final MGF1ParameterSpec SHA256 = 85 new MGF1ParameterSpec("SHA-256"); 86 87 /** 88 * The MGF1ParameterSpec which uses "SHA-384" message digest 89 */ 90 public static final MGF1ParameterSpec SHA384 = 91 new MGF1ParameterSpec("SHA-384"); 92 93 /** 94 * The MGF1ParameterSpec which uses SHA-512 message digest 95 */ 96 public static final MGF1ParameterSpec SHA512 = 97 new MGF1ParameterSpec("SHA-512"); 98 99 /** 100 * The MGF1ParameterSpec which uses SHA-512/224 message digest 101 */ 102 public static final MGF1ParameterSpec SHA512_224 = 103 new MGF1ParameterSpec("SHA-512/224"); 104 105 /** 106 * The MGF1ParameterSpec which uses SHA-512/256 message digest 107 */ 108 public static final MGF1ParameterSpec SHA512_256 = 109 new MGF1ParameterSpec("SHA-512/256"); 110 111 private String mdName; 112 113 /** 114 * Constructs a parameter set for mask generation function MGF1 115 * as defined in the PKCS #1 standard. 116 * 117 * @param mdName the algorithm name for the message digest 118 * used in this mask generation function MGF1. 119 * @exception NullPointerException if {@code mdName} is null. 120 */ 121 public MGF1ParameterSpec(String mdName) { 122 if (mdName == null) { 123 throw new NullPointerException("digest algorithm is null"); 124 } 125 this.mdName = mdName; 126 } 127 128 /** 129 * Returns the algorithm name of the message digest used by the mask 130 * generation function. 131 * 132 * @return the algorithm name of the message digest. 133 */ 134 public String getDigestAlgorithm() { 135 return mdName; 136 } 137 }