001 package com.nimbusds.jose;
002
003
004 import java.text.ParseException;
005
006 import net.jcip.annotations.Immutable;
007 import net.minidev.json.JSONObject;
008
009 import com.nimbusds.jose.util.Base64URL;
010 import com.nimbusds.jose.util.JSONObjectUtils;
011
012
013 /**
014 * Public {@link KeyType#RSA RSA} JSON Web Key (JWK). This class is immutable.
015 *
016 * <p>Example JSON:
017 *
018 * <pre>
019 * {
020 * "kty" : "RSA",
021 * "n" : "0vx7agoebGcQSuuPiLJXZptN9nndrQmbXEps2aiAFbWhM78LhWx
022 * 4cbbfAAtVT86zwu1RK7aPFFxuhDR1L6tSoc_BJECPebWKRXjBZCiFV4n3oknjhMs
023 * tn64tZ_2W-5JsGY4Hc5n9yBXArwl93lqt7_RN5w6Cf0h4QyQ5v-65YGjQR0_FDW2
024 * QvzqY368QQMicAtaSqzs8KJZgnYb9c7d0zgdAZHzu6qMQvRL5hajrn1n91CbOpbI
025 * SD08qNLyrdkt-bFTWhAI4vMQFh6WeZu0fM4lFd2NcRwr3XPksINHaQ-G_xBniIqb
026 * w0Ls1jF44-csFCur-kEgU8awapJzKnqDKgw",
027 * "e" : "AQAB",
028 * "alg" : "RS256"
029 * "kid" : "2011-04-29"}
030 * }
031 * </pre>
032 *
033 * <p>See http://en.wikipedia.org/wiki/RSA_%28algorithm%29
034 *
035 * @author Vladimir Dzhuvinov
036 * @version $version$ (2013-01-08)
037 */
038 @Immutable
039 public final class RSAKey extends JWK {
040
041
042 /**
043 * The modulus value for the RSA public key.
044 */
045 private final Base64URL n;
046
047
048 /**
049 * The exponent value for the RSA public key.
050 */
051 private final Base64URL e;
052
053
054 /**
055 * Creates a new public RSA JSON Web Key (JWK) with the specified
056 * parameters.
057 *
058 * @param n The the modulus value for the RSA public key. It is
059 * represented as the Base64URL encoding of value's big
060 * endian representation. Must not be {@code null}.
061 * @param e The exponent value for the RSA public key. It is
062 * represented as the Base64URL encoding of value's big
063 * endian representation. Must not be {@code null}.
064 * @param use The key use. {@code null} if not specified.
065 * @param alg The intended JOSE algorithm for the key, {@code null} if
066 * not specified.
067 * @param kid The key ID. {@code null} if not specified.
068 */
069 public RSAKey(final Base64URL n, final Base64URL e,
070 final Use use, final Algorithm alg, final String kid) {
071
072 super(KeyType.RSA, use, alg, kid);
073
074 if (n == null) {
075 throw new IllegalArgumentException("The modulus value must not be null");
076 }
077
078 this.n = n;
079
080 if (e == null) {
081 throw new IllegalArgumentException("The exponent value must not be null");
082 }
083
084 this.e = e;
085 }
086
087
088 /**
089 * Returns the modulus value for this RSA public key. It is represented
090 * as the Base64URL encoding of the value's big ending representation.
091 *
092 * @return The RSA public key modulus.
093 */
094 public Base64URL getModulus() {
095
096 return n;
097 }
098
099
100 /**
101 * Returns the exponent value for this RSA public key. It is represented
102 * as the Base64URL encoding of the value's big ending representation.
103 *
104 * @return The RSA public key exponent.
105 */
106 public Base64URL getExponent() {
107
108 return e;
109 }
110
111
112 @Override
113 public JSONObject toJSONObject() {
114
115 JSONObject o = super.toJSONObject();
116
117 // Append RSA public key specific attributes
118 o.put("n", n.toString());
119 o.put("e", e.toString());
120
121 return o;
122 }
123
124
125 /**
126 * Parses a public RSA JWK from the specified JSON object
127 * representation.
128 *
129 * @param jsonObject The JSON object to parse. Must not be
130 * @code null}.
131 *
132 * @return The RSA Key.
133 *
134 * @throws ParseException If the JSON object couldn't be parsed to valid
135 * RSA JWK.
136 */
137 public static RSAKey parse(final JSONObject jsonObject)
138 throws ParseException {
139
140 // Parse the mandatory parameters first
141 KeyType kty = KeyType.parse(JSONObjectUtils.getString(jsonObject, "kty"));
142 Base64URL mod = new Base64URL(JSONObjectUtils.getString(jsonObject, "n"));
143 Base64URL exp = new Base64URL(JSONObjectUtils.getString(jsonObject, "e"));
144
145 // Get optional key use
146 Use use = JWK.parseKeyUse(jsonObject);
147
148 // Get optional intended algorithm
149 Algorithm alg = JWK.parseAlgorithm(jsonObject);
150
151 // Get optional key ID
152 String id = JWK.parseKeyID(jsonObject);
153
154 // Check key type
155 if (kty != KeyType.RSA) {
156 throw new ParseException("The key type \"kty\" must be RSA", 0);
157 }
158
159 return new RSAKey(mod, exp, use, alg, id);
160 }
161 }