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1 /* |
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2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. Oracle designates this |
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8 * particular file as subject to the "Classpath" exception as provided |
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9 * by Oracle in the LICENSE file that accompanied this code. |
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10 * |
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11 * This code is distributed in the hope that it will be useful, but WITHOUT |
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12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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14 * version 2 for more details (a copy is included in the LICENSE file that |
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15 * accompanied this code). |
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16 * |
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17 * You should have received a copy of the GNU General Public License version |
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18 * 2 along with this work; if not, write to the Free Software Foundation, |
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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20 * |
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21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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22 * or visit www.oracle.com if you need additional information or have any |
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23 * questions. |
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24 */ |
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25 |
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26 package java.security; |
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27 |
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28 import java.security.spec.KeySpec; |
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29 import java.security.spec.InvalidKeySpecException; |
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30 |
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31 /** |
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32 * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>) |
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33 * for the {@code KeyFactory} class. |
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34 * All the abstract methods in this class must be implemented by each |
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35 * cryptographic service provider who wishes to supply the implementation |
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36 * of a key factory for a particular algorithm. |
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37 * |
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38 * <P> Key factories are used to convert <I>keys</I> (opaque |
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39 * cryptographic keys of type {@code Key}) into <I>key specifications</I> |
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40 * (transparent representations of the underlying key material), and vice |
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41 * versa. |
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42 * |
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43 * <P> Key factories are bi-directional. That is, they allow you to build an |
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44 * opaque key object from a given key specification (key material), or to |
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45 * retrieve the underlying key material of a key object in a suitable format. |
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46 * |
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47 * <P> Multiple compatible key specifications may exist for the same key. |
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48 * For example, a DSA public key may be specified using |
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49 * {@code DSAPublicKeySpec} or |
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50 * {@code X509EncodedKeySpec}. A key factory can be used to translate |
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51 * between compatible key specifications. |
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52 * |
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53 * <P> A provider should document all the key specifications supported by its |
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54 * key factory. |
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55 * |
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56 * @author Jan Luehe |
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57 * |
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58 * |
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59 * @see KeyFactory |
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60 * @see Key |
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61 * @see PublicKey |
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62 * @see PrivateKey |
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63 * @see java.security.spec.KeySpec |
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64 * @see java.security.spec.DSAPublicKeySpec |
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65 * @see java.security.spec.X509EncodedKeySpec |
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66 * |
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67 * @since 1.2 |
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68 */ |
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69 |
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70 public abstract class KeyFactorySpi { |
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71 |
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72 /** |
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73 * Generates a public key object from the provided key |
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74 * specification (key material). |
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75 * |
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76 * @param keySpec the specification (key material) of the public key. |
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77 * |
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78 * @return the public key. |
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79 * |
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80 * @exception InvalidKeySpecException if the given key specification |
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81 * is inappropriate for this key factory to produce a public key. |
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82 */ |
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83 protected abstract PublicKey engineGeneratePublic(KeySpec keySpec) |
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84 throws InvalidKeySpecException; |
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85 |
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86 /** |
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87 * Generates a private key object from the provided key |
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88 * specification (key material). |
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89 * |
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90 * @param keySpec the specification (key material) of the private key. |
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91 * |
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92 * @return the private key. |
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93 * |
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94 * @exception InvalidKeySpecException if the given key specification |
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95 * is inappropriate for this key factory to produce a private key. |
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96 */ |
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97 protected abstract PrivateKey engineGeneratePrivate(KeySpec keySpec) |
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98 throws InvalidKeySpecException; |
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99 |
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100 /** |
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101 * Returns a specification (key material) of the given key |
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102 * object. |
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103 * {@code keySpec} identifies the specification class in which |
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104 * the key material should be returned. It could, for example, be |
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105 * {@code DSAPublicKeySpec.class}, to indicate that the |
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106 * key material should be returned in an instance of the |
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107 * {@code DSAPublicKeySpec} class. |
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108 * |
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109 * @param <T> the type of the key specification to be returned |
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110 * |
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111 * @param key the key. |
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112 * |
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113 * @param keySpec the specification class in which |
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114 * the key material should be returned. |
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115 * |
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116 * @return the underlying key specification (key material) in an instance |
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117 * of the requested specification class. |
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118 |
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119 * @exception InvalidKeySpecException if the requested key specification is |
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120 * inappropriate for the given key, or the given key cannot be dealt with |
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121 * (e.g., the given key has an unrecognized format). |
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122 */ |
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123 protected abstract <T extends KeySpec> |
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124 T engineGetKeySpec(Key key, Class<T> keySpec) |
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125 throws InvalidKeySpecException; |
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126 |
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127 /** |
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128 * Translates a key object, whose provider may be unknown or |
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129 * potentially untrusted, into a corresponding key object of this key |
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130 * factory. |
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131 * |
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132 * @param key the key whose provider is unknown or untrusted. |
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133 * |
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134 * @return the translated key. |
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135 * |
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136 * @exception InvalidKeyException if the given key cannot be processed |
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137 * by this key factory. |
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138 */ |
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139 protected abstract Key engineTranslateKey(Key key) |
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140 throws InvalidKeyException; |
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141 |
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142 } |