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Diffstat (limited to 'gcc-4.4.3/libjava/classpath/gnu/java/security/key/rsa/RSAKeyPairGenerator.java')
| -rw-r--r-- | gcc-4.4.3/libjava/classpath/gnu/java/security/key/rsa/RSAKeyPairGenerator.java | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/gcc-4.4.3/libjava/classpath/gnu/java/security/key/rsa/RSAKeyPairGenerator.java b/gcc-4.4.3/libjava/classpath/gnu/java/security/key/rsa/RSAKeyPairGenerator.java new file mode 100644 index 000000000..c31cc4cc1 --- /dev/null +++ b/gcc-4.4.3/libjava/classpath/gnu/java/security/key/rsa/RSAKeyPairGenerator.java @@ -0,0 +1,246 @@ +/* RSAKeyPairGenerator.java -- + Copyright 2001, 2002, 2003, 2006 Free Software Foundation, Inc. + +This file is a part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2 of the License, or (at +your option) any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; if not, write to the Free Software +Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 +USA + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package gnu.java.security.key.rsa; + +import gnu.java.security.Configuration; +import gnu.java.security.Registry; +import gnu.java.security.key.IKeyPairGenerator; +import gnu.java.security.util.PRNG; + +import java.math.BigInteger; +import java.security.KeyPair; +import java.security.PrivateKey; +import java.security.PublicKey; +import java.security.SecureRandom; +import java.security.spec.RSAKeyGenParameterSpec; +import java.util.Map; +import java.util.logging.Logger; + +/** + * A key-pair generator for asymetric keys to use in conjunction with the RSA + * scheme. + * <p> + * Reference: + * <ol> + * <li><a + * href="http://www.cosic.esat.kuleuven.ac.be/nessie/workshop/submissions/rsa-pss.zip"> + * RSA-PSS Signature Scheme with Appendix</a>, part B. Primitive specification + * and supporting documentation. Jakob Jonsson and Burt Kaliski. </li> + * <li><a href="http://www.cacr.math.uwaterloo.ca/hac/">Handbook of Applied + * Cryptography</a>, Alfred J. Menezes, Paul C. van Oorschot and Scott A. + * Vanstone. Section 11.3 RSA and related signature schemes.</li> + * </ol> + */ +public class RSAKeyPairGenerator + implements IKeyPairGenerator +{ + private static final Logger log = Logger.getLogger(RSAKeyPairGenerator.class.getName()); + + /** The BigInteger constant 1. */ + private static final BigInteger ONE = BigInteger.ONE; + + /** The BigInteger constant 2. */ + private static final BigInteger TWO = BigInteger.valueOf(2L); + + /** Property name of the length (Integer) of the modulus of an RSA key. */ + public static final String MODULUS_LENGTH = "gnu.crypto.rsa.L"; + + /** + * Property name of an optional {@link SecureRandom} instance to use. The + * default is to use a classloader singleton from {@link PRNG}. + */ + public static final String SOURCE_OF_RANDOMNESS = "gnu.crypto.rsa.prng"; + + /** + * Property name of an optional {@link RSAKeyGenParameterSpec} instance to use + * for this generator's <code>n</code>, and <code>e</code> values. The + * default is to generate <code>n</code> and use a fixed value for + * <code>e</.code> (Fermat's F4 number). + */ + public static final String RSA_PARAMETERS = "gnu.crypto.rsa.params"; + + /** + * Property name of the preferred encoding format to use when externalizing + * generated instance of key-pairs from this generator. The property is taken + * to be an {@link Integer} that encapsulates an encoding format identifier. + */ + public static final String PREFERRED_ENCODING_FORMAT = "gnu.crypto.rsa.encoding"; + + /** Default value for the modulus length. */ + private static final int DEFAULT_MODULUS_LENGTH = 1024; + + /** Default encoding format to use when none was specified. */ + private static final int DEFAULT_ENCODING_FORMAT = Registry.RAW_ENCODING_ID; + + /** The desired bit length of the modulus. */ + private int L; + + /** + * This implementation uses, by default, Fermat's F4 number as the public + * exponent. + */ + private BigInteger e = BigInteger.valueOf(65537L); + + /** The optional {@link SecureRandom} instance to use. */ + private SecureRandom rnd = null; + + /** Our default source of randomness. */ + private PRNG prng = null; + + /** Preferred encoding format of generated keys. */ + private int preferredFormat; + + // implicit 0-arguments constructor + + public String name() + { + return Registry.RSA_KPG; + } + + /** + * Configures this instance. + * + * @param attributes the map of name/value pairs to use. + * @exception IllegalArgumentException if the designated MODULUS_LENGTH value + * is less than 1024. + */ + public void setup(Map attributes) + { + if (Configuration.DEBUG) + log.entering(this.getClass().getName(), "setup", attributes); + // do we have a SecureRandom, or should we use our own? + rnd = (SecureRandom) attributes.get(SOURCE_OF_RANDOMNESS); + // are we given a set of RSA params or we shall use our own? + RSAKeyGenParameterSpec params = (RSAKeyGenParameterSpec) attributes.get(RSA_PARAMETERS); + // find out the modulus length + if (params != null) + { + L = params.getKeysize(); + e = params.getPublicExponent(); + } + else + { + Integer l = (Integer) attributes.get(MODULUS_LENGTH); + L = (l == null ? DEFAULT_MODULUS_LENGTH : l.intValue()); + } + if (L < 1024) + throw new IllegalArgumentException(MODULUS_LENGTH); + + // what is the preferred encoding format + Integer formatID = (Integer) attributes.get(PREFERRED_ENCODING_FORMAT); + preferredFormat = formatID == null ? DEFAULT_ENCODING_FORMAT + : formatID.intValue(); + if (Configuration.DEBUG) + log.exiting(this.getClass().getName(), "setup"); + } + + /** + * <p> + * The algorithm used here is described in <i>nessie-pss-B.pdf</i> document + * which is part of the RSA-PSS submission to NESSIE. + * </p> + * + * @return an RSA keypair. + */ + public KeyPair generate() + { + if (Configuration.DEBUG) + log.entering(this.getClass().getName(), "generate"); + BigInteger p, q, n, d; + // 1. Generate a prime p in the interval [2**(M-1), 2**M - 1], where + // M = CEILING(L/2), and such that GCD(p, e) = 1 + int M = (L + 1) / 2; + BigInteger lower = TWO.pow(M - 1); + BigInteger upper = TWO.pow(M).subtract(ONE); + byte[] kb = new byte[(M + 7) / 8]; // enough bytes to frame M bits + step1: while (true) + { + nextRandomBytes(kb); + p = new BigInteger(1, kb).setBit(0); + if (p.compareTo(lower) >= 0 && p.compareTo(upper) <= 0 + && p.isProbablePrime(80) && p.gcd(e).equals(ONE)) + break step1; + } + // 2. Generate a prime q such that the product of p and q is an L-bit + // number, and such that GCD(q, e) = 1 + step2: while (true) + { + nextRandomBytes(kb); + q = new BigInteger(1, kb).setBit(0); + n = p.multiply(q); + if (n.bitLength() == L && q.isProbablePrime(80) && q.gcd(e).equals(ONE)) + break step2; + // TODO: test for p != q + } + // TODO: ensure p < q + // 3. Put n = pq. The public key is (n, e). + // 4. Compute the parameters necessary for the private key K (see + // Section 2.2). + BigInteger phi = p.subtract(ONE).multiply(q.subtract(ONE)); + d = e.modInverse(phi); + // 5. Output the public key and the private key. + PublicKey pubK = new GnuRSAPublicKey(preferredFormat, n, e); + PrivateKey secK = new GnuRSAPrivateKey(preferredFormat, p, q, e, d); + KeyPair result = new KeyPair(pubK, secK); + if (Configuration.DEBUG) + log.exiting(this.getClass().getName(), "generate", result); + return result; + } + + /** + * Fills the designated byte array with random data. + * + * @param buffer the byte array to fill with random data. + */ + private void nextRandomBytes(byte[] buffer) + { + if (rnd != null) + rnd.nextBytes(buffer); + else + getDefaultPRNG().nextBytes(buffer); + } + + private PRNG getDefaultPRNG() + { + if (prng == null) + prng = PRNG.getInstance(); + + return prng; + } +} |