From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- .../gnu/java/security/sig/dss/DSSSignature.java | 275 +++++++++++++++++++++ 1 file changed, 275 insertions(+) create mode 100644 libjava/classpath/gnu/java/security/sig/dss/DSSSignature.java (limited to 'libjava/classpath/gnu/java/security/sig/dss/DSSSignature.java') diff --git a/libjava/classpath/gnu/java/security/sig/dss/DSSSignature.java b/libjava/classpath/gnu/java/security/sig/dss/DSSSignature.java new file mode 100644 index 000000000..024521ba4 --- /dev/null +++ b/libjava/classpath/gnu/java/security/sig/dss/DSSSignature.java @@ -0,0 +1,275 @@ +/* DSSSignature.java -- + Copyright (C) 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.sig.dss; + +import gnu.java.security.Registry; +import gnu.java.security.hash.IMessageDigest; +import gnu.java.security.hash.Sha160; +import gnu.java.security.prng.IRandom; +import gnu.java.security.sig.BaseSignature; +import gnu.java.security.sig.ISignature; + +import java.math.BigInteger; +import java.security.PrivateKey; +import java.security.PublicKey; +import java.security.interfaces.DSAPrivateKey; +import java.security.interfaces.DSAPublicKey; +import java.util.HashMap; +import java.util.Map; +import java.util.Random; + +/** + * The DSS (Digital Signature Standard) algorithm makes use of the following + * parameters: + *
    + *
  1. p: A prime modulus, where + * 2L-1 < p < 2L for 512 <= L + * <= 1024 and L a multiple of 64.
    2. + *
  2. q: A prime divisor of p - 1, where 2159 + * < q < 2160.
    3. + *
  3. g: Where g = h(p-1)/q mod p, where + * h is any integer with 1 < h < p - 1 such + * that h (p-1)/q mod p > 1 (g has order + * q mod p).
    4. + *
  4. x: A randomly or pseudorandomly generated integer with 0 < x + * < q.
    5. + *
  5. y: y = gx mod p.
    6. + *
  6. k: A randomly or pseudorandomly generated integer with 0 < k + * < q.
    7. + *
+ *

+ * The integers p, q, and g can be + * public and can be common to a group of users. A user's private and public + * keys are x and y, respectively. They are + * normally fixed for a period of time. Parameters x and + * k are used for signature generation only, and must be kept + * secret. Parameter k must be regenerated for each signature. + *

+ * The signature of a message M is the pair of numbers + * r and s computed according to the equations below: + *

+ *

+ * In the above, k-1 is the multiplicative inverse of + * k, mod q; i.e., (k-1 k) mod q = + * 1 and 0 < k-1 < q. The value of SHA(M) + * is a 160-bit string output by the Secure Hash Algorithm specified in FIPS + * 180. For use in computing s, this string must be converted to + * an integer. + *

+ * As an option, one may wish to check if r == 0 or s == 0 + * . + * If either r == 0 or s == 0, a new value of + * k should be generated and the signature should be recalculated + * (it is extremely unlikely that r == 0 or s == 0 if + * signatures are generated properly). + *

+ * The signature is transmitted along with the message to the verifier. + *

+ * References: + *

    + *
  1. Digital Signature + * Standard (DSS), Federal Information Processing Standards Publication + * 186. National Institute of Standards and Technology.
    2. + *
+ */ +public class DSSSignature + extends BaseSignature +{ + /** Trivial 0-arguments constructor. */ + public DSSSignature() + { + super(Registry.DSS_SIG, new Sha160()); + } + + /** Private constructor for cloning purposes. */ + private DSSSignature(DSSSignature that) + { + this(); + + this.publicKey = that.publicKey; + this.privateKey = that.privateKey; + this.md = (IMessageDigest) that.md.clone(); + } + + public static final BigInteger[] sign(final DSAPrivateKey k, final byte[] h) + { + final DSSSignature sig = new DSSSignature(); + final Map attributes = new HashMap(); + attributes.put(ISignature.SIGNER_KEY, k); + sig.setupSign(attributes); + return sig.computeRS(h); + } + + public static final BigInteger[] sign(final DSAPrivateKey k, final byte[] h, + Random rnd) + { + final DSSSignature sig = new DSSSignature(); + final Map attributes = new HashMap(); + attributes.put(ISignature.SIGNER_KEY, k); + if (rnd != null) + attributes.put(ISignature.SOURCE_OF_RANDOMNESS, rnd); + + sig.setupSign(attributes); + return sig.computeRS(h); + } + + public static final BigInteger[] sign(final DSAPrivateKey k, final byte[] h, + IRandom irnd) + { + final DSSSignature sig = new DSSSignature(); + final Map attributes = new HashMap(); + attributes.put(ISignature.SIGNER_KEY, k); + if (irnd != null) + attributes.put(ISignature.SOURCE_OF_RANDOMNESS, irnd); + + sig.setupSign(attributes); + return sig.computeRS(h); + } + + public static final boolean verify(final DSAPublicKey k, final byte[] h, + final BigInteger[] rs) + { + final DSSSignature sig = new DSSSignature(); + final Map attributes = new HashMap(); + attributes.put(ISignature.VERIFIER_KEY, k); + sig.setupVerify(attributes); + return sig.checkRS(rs, h); + } + + public Object clone() + { + return new DSSSignature(this); + } + + protected void setupForVerification(PublicKey k) + throws IllegalArgumentException + { + if (! (k instanceof DSAPublicKey)) + throw new IllegalArgumentException(); + + this.publicKey = k; + } + + protected void setupForSigning(PrivateKey k) throws IllegalArgumentException + { + if (! (k instanceof DSAPrivateKey)) + throw new IllegalArgumentException(); + + this.privateKey = k; + } + + protected Object generateSignature() throws IllegalStateException + { + final BigInteger[] rs = computeRS(md.digest()); + return encodeSignature(rs[0], rs[1]); + } + + protected boolean verifySignature(Object sig) throws IllegalStateException + { + final BigInteger[] rs = decodeSignature(sig); + return checkRS(rs, md.digest()); + } + + /** + * Returns the output of a signature generation phase. + * + * @return an object encapsulating the DSS signature pair r and + * s. + */ + private Object encodeSignature(BigInteger r, BigInteger s) + { + return new BigInteger[] { r, s }; + } + + /** + * Returns the output of a previously generated signature object as a pair of + * {@link java.math.BigInteger}. + * + * @return the DSS signature pair r and s. + */ + private BigInteger[] decodeSignature(Object signature) + { + return (BigInteger[]) signature; + } + + private BigInteger[] computeRS(final byte[] digestBytes) + { + final BigInteger p = ((DSAPrivateKey) privateKey).getParams().getP(); + final BigInteger q = ((DSAPrivateKey) privateKey).getParams().getQ(); + final BigInteger g = ((DSAPrivateKey) privateKey).getParams().getG(); + final BigInteger x = ((DSAPrivateKey) privateKey).getX(); + final BigInteger m = new BigInteger(1, digestBytes); + BigInteger k, r, s; + final byte[] kb = new byte[20]; // we'll use 159 bits only + while (true) + { + this.nextRandomBytes(kb); + k = new BigInteger(1, kb); + k.clearBit(159); + r = g.modPow(k, p).mod(q); + if (r.equals(BigInteger.ZERO)) + continue; + + s = m.add(x.multiply(r)).multiply(k.modInverse(q)).mod(q); + if (s.equals(BigInteger.ZERO)) + continue; + + break; + } + return new BigInteger[] { r, s }; + } + + private boolean checkRS(final BigInteger[] rs, final byte[] digestBytes) + { + final BigInteger r = rs[0]; + final BigInteger s = rs[1]; + final BigInteger g = ((DSAPublicKey) publicKey).getParams().getG(); + final BigInteger p = ((DSAPublicKey) publicKey).getParams().getP(); + final BigInteger q = ((DSAPublicKey) publicKey).getParams().getQ(); + final BigInteger y = ((DSAPublicKey) publicKey).getY(); + final BigInteger w = s.modInverse(q); + final BigInteger u1 = w.multiply(new BigInteger(1, digestBytes)).mod(q); + final BigInteger u2 = r.multiply(w).mod(q); + final BigInteger v = g.modPow(u1, p).multiply(y.modPow(u2, p)).mod(p).mod(q); + return v.equals(r); + } +} -- cgit v1.2.3