From ce57ab760f69de6db452def7ffbf5b114a2d8694 Mon Sep 17 00:00:00 2001 From: mark Date: Fri, 10 Mar 2006 21:46:48 +0000 Subject: Imported GNU Classpath 0.90 * scripts/makemake.tcl: Set gnu/java/awt/peer/swing to ignore. * gnu/classpath/jdwp/VMFrame.java (SIZE): New constant. * java/lang/VMCompiler.java: Use gnu.java.security.hash.MD5. * java/lang/Math.java: New override file. * java/lang/Character.java: Merged from Classpath. (start, end): Now 'int's. (canonicalName): New field. (CANONICAL_NAME, NO_SPACES_NAME, CONSTANT_NAME): New constants. (UnicodeBlock): Added argument. (of): New overload. (forName): New method. Updated unicode blocks. (sets): Updated. * sources.am: Regenerated. * Makefile.in: Likewise. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@111942 138bc75d-0d04-0410-961f-82ee72b054a4 --- .../gnu/java/security/sig/dss/DSSSignature.java | 347 +++++++++++++++++++++ .../security/sig/dss/DSSSignatureRawCodec.java | 191 ++++++++++++ .../security/sig/dss/DSSSignatureX509Codec.java | 193 ++++++++++++ 3 files changed, 731 insertions(+) create mode 100644 libjava/classpath/gnu/java/security/sig/dss/DSSSignature.java create mode 100644 libjava/classpath/gnu/java/security/sig/dss/DSSSignatureRawCodec.java create mode 100644 libjava/classpath/gnu/java/security/sig/dss/DSSSignatureX509Codec.java (limited to 'libjava/classpath/gnu/java/security/sig/dss') 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 00000000000..6bedfaefa3a --- /dev/null +++ b/libjava/classpath/gnu/java/security/sig/dss/DSSSignature.java @@ -0,0 +1,347 @@ +/* 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. + *
+ * + * @version $Revision: 1.1 $ + */ +public class DSSSignature extends BaseSignature +{ + + // Constants and variables + // ------------------------------------------------------------------------- + + // Constructor(s) + // ------------------------------------------------------------------------- + + /** 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(); + } + + // Class methods + // ------------------------------------------------------------------------- + + 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); + } + + // Implementation of abstract methods in superclass + // ------------------------------------------------------------------------- + + 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 + { + // BigInteger p = ((DSAPrivateKey) privateKey).getParams().getP(); + // BigInteger q = ((DSAPrivateKey) privateKey).getParams().getQ(); + // BigInteger g = ((DSAPrivateKey) privateKey).getParams().getG(); + // BigInteger x = ((DSAPrivateKey) privateKey).getX(); + // BigInteger m = new BigInteger(1, md.digest()); + // BigInteger k, r, s; + // + // 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; + // } + final BigInteger[] rs = computeRS(md.digest()); + + // return encodeSignature(r, s); + return encodeSignature(rs[0], rs[1]); + } + + protected boolean verifySignature(Object sig) throws IllegalStateException + { + final BigInteger[] rs = decodeSignature(sig); + // BigInteger r = rs[0]; + // BigInteger s = rs[1]; + // + // BigInteger g = ((DSAPublicKey) publicKey).getParams().getG(); + // BigInteger p = ((DSAPublicKey) publicKey).getParams().getP(); + // BigInteger q = ((DSAPublicKey) publicKey).getParams().getQ(); + // BigInteger y = ((DSAPublicKey) publicKey).getY(); + // BigInteger w = s.modInverse(q); + // + // byte bytes[] = md.digest(); + // BigInteger u1 = w.multiply(new BigInteger(1, bytes)).mod(q); + // BigInteger u2 = r.multiply(w).mod(q); + // + // BigInteger v = g.modPow(u1, p).multiply(y.modPow(u2, p)).mod(p).mod(q); + // return v.equals(r); + return checkRS(rs, md.digest()); + } + + // Other instance methods + // ------------------------------------------------------------------------- + + /** + * 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); + } +} diff --git a/libjava/classpath/gnu/java/security/sig/dss/DSSSignatureRawCodec.java b/libjava/classpath/gnu/java/security/sig/dss/DSSSignatureRawCodec.java new file mode 100644 index 00000000000..02f6b1ddc41 --- /dev/null +++ b/libjava/classpath/gnu/java/security/sig/dss/DSSSignatureRawCodec.java @@ -0,0 +1,191 @@ +/* DSSSignatureRawCodec.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.sig.ISignatureCodec; + +import java.io.ByteArrayOutputStream; +import java.math.BigInteger; + +/** + *

An object that implements the {@link ISignatureCodec} operations for the + * Raw format to use with DSS signatures.

+ * + * @version $Revision: 1.1 $ + */ +public class DSSSignatureRawCodec implements ISignatureCodec +{ + + // Constants and variables + // ------------------------------------------------------------------------- + + // Constructor(s) + // ------------------------------------------------------------------------- + + // implicit 0-arguments constructor + + // Class methods + // ------------------------------------------------------------------------- + + // Instance methods + // ------------------------------------------------------------------------- + + // gnu.crypto.sig.ISignatureCodec interface implementation ----------------- + + public int getFormatID() + { + return RAW_FORMAT; + } + + /** + *

Returns the encoded form of the designated DSS (Digital Signature + * Standard) signature object according to the Raw format supported by + * this library.

+ * + *

The Raw format for a DSA signature, in this implementation, is a + * byte sequence consisting of the following:

+ * + *
    + *
  1. 4-byte magic consisting of the value of the literal + * {@link Registry#MAGIC_RAW_DSS_SIGNATURE},
    2. + *
  2. 1-byte version consisting of the constant: 0x01,
    3. + *
  3. 4-byte count of following bytes representing the DSS parameter + * r in internet order,
    4. + *
  4. n-bytes representation of a {@link BigInteger} obtained by invoking + * the toByteArray() method on the DSS parameter r,
    5. + *
  5. 4-byte count of following bytes representing the DSS parameter + * s,
    6. + *
  6. n-bytes representation of a {@link BigInteger} obtained by invoking + * the toByteArray() method on the DSS parameter s.
    7. + *
+ * + * @param signature the signature to encode, consisting of the two DSS + * parameters r and s as a {@link java.math.BigInteger} + * array. + * @return the Raw format encoding of the designated signature. + * @exception IllegalArgumentException if the designated signature is not a + * DSS (Digital Signature Standard) one. + */ + public byte[] encodeSignature(Object signature) + { + BigInteger r, s; + try + { + BigInteger[] sig = (BigInteger[]) signature; + r = sig[0]; + s = sig[1]; + } + catch (Exception x) + { + throw new IllegalArgumentException("key"); + } + + ByteArrayOutputStream baos = new ByteArrayOutputStream(); + + // magic + baos.write(Registry.MAGIC_RAW_DSS_SIGNATURE[0]); + baos.write(Registry.MAGIC_RAW_DSS_SIGNATURE[1]); + baos.write(Registry.MAGIC_RAW_DSS_SIGNATURE[2]); + baos.write(Registry.MAGIC_RAW_DSS_SIGNATURE[3]); + + // version + baos.write(0x01); + + // r + byte[] buffer = r.toByteArray(); + int length = buffer.length; + baos.write(length >>> 24); + baos.write((length >>> 16) & 0xFF); + baos.write((length >>> 8) & 0xFF); + baos.write(length & 0xFF); + baos.write(buffer, 0, length); + + // s + buffer = s.toByteArray(); + length = buffer.length; + baos.write(length >>> 24); + baos.write((length >>> 16) & 0xFF); + baos.write((length >>> 8) & 0xFF); + baos.write(length & 0xFF); + baos.write(buffer, 0, length); + + return baos.toByteArray(); + } + + public Object decodeSignature(byte[] k) + { + // magic + if (k[0] != Registry.MAGIC_RAW_DSS_SIGNATURE[0] + || k[1] != Registry.MAGIC_RAW_DSS_SIGNATURE[1] + || k[2] != Registry.MAGIC_RAW_DSS_SIGNATURE[2] + || k[3] != Registry.MAGIC_RAW_DSS_SIGNATURE[3]) + { + throw new IllegalArgumentException("magic"); + } + + // version + if (k[4] != 0x01) + { + throw new IllegalArgumentException("version"); + } + + int i = 5; + int l; + byte[] buffer; + + // r + l = k[i++] << 24 | (k[i++] & 0xFF) << 16 | (k[i++] & 0xFF) << 8 + | (k[i++] & 0xFF); + buffer = new byte[l]; + System.arraycopy(k, i, buffer, 0, l); + i += l; + BigInteger r = new BigInteger(1, buffer); + + // s + l = k[i++] << 24 | (k[i++] & 0xFF) << 16 | (k[i++] & 0xFF) << 8 + | (k[i++] & 0xFF); + buffer = new byte[l]; + System.arraycopy(k, i, buffer, 0, l); + i += l; + BigInteger s = new BigInteger(1, buffer); + + return new BigInteger[] { r, s }; + } +} diff --git a/libjava/classpath/gnu/java/security/sig/dss/DSSSignatureX509Codec.java b/libjava/classpath/gnu/java/security/sig/dss/DSSSignatureX509Codec.java new file mode 100644 index 00000000000..0fdb754a982 --- /dev/null +++ b/libjava/classpath/gnu/java/security/sig/dss/DSSSignatureX509Codec.java @@ -0,0 +1,193 @@ +/* DSSSignatureX509Codec.java -- X.509 encoder/decoder for DSS signatures + Copyright (C) 2006 Free Software Foundation, Inc. + +This file is 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, 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; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, 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.der.DER; +import gnu.java.security.der.DERReader; +import gnu.java.security.der.DERValue; +import gnu.java.security.der.DERWriter; +import gnu.java.security.sig.ISignatureCodec; +import gnu.java.security.util.DerUtil; + +import java.io.ByteArrayOutputStream; +import java.io.IOException; +import java.math.BigInteger; +import java.security.InvalidParameterException; +import java.util.ArrayList; + +/** + * An implementation of an {@link ISignatureCodec} that knows to encode and + * decode DSS signatures into the raw bytes which would constitute a DER-encoded + * form of the ASN.1 structure defined in RFC-2459, and RFC-2313 as described in + * the next paragraphs. + *

+ * Digital signatures when transmitted in an X.509 certificates are encoded + * in DER (Distinguished Encoding Rules) as a BIT STRING; i.e. + * + * 

+ * Certificate ::= SEQUENCE {
+ *   tbsCertificate       TBSCertificate,
+ *   signatureAlgorithm   AlgorithmIdentifier,
+ *   signature            BIT STRING
+ * }
+ *
+ *

+ * The output of the encoder, and the input of the decoder, of this codec are + * then the raw bytes of such a BIT STRING; i.e. not the DER-encoded + * form itself. + *

+ * RFC-2459 states that, for the Digital Signature Standard (DSS), which + * generates two MPIs, commonly called r and s, as the + * result of digitally signing a message, these two numbers will be transferred + * as the following ASN.1 structure: + * + * 

+ *   Dss-Sig-Value ::= SEQUENCE {
+ *     r  INTEGER,
+ *     s  INTEGER
+ *   }
+ *
+ *

+ * Client code that needs to build a DER BIT STRING MUST construct such + * an ASN.1 value. The following is an example of how to do this: + *

+ * 

+ * ...
+ * import gnu.java.security.der.BitString;
+ * import gnu.java.security.der.DER;
+ * import gnu.java.security.der.DERValue;
+ * ...
+ * DERValue bitString = new DERValue(DER.BIT_STRING, new BitString(sigBytes));
+ * ...
+ *
+ */ +public class DSSSignatureX509Codec + implements ISignatureCodec +{ + // implicit 0-arguments constructor + + public int getFormatID() + { + return Registry.X509_ENCODING_ID; + } + + /** + * Encodes a DSS Signature output as the signature raw bytes which can + * be used to construct an ASN.1 DER-encoded BIT STRING as defined in the + * documentation of this class. + * + * @param signature the output of the DSS signature algorithm; i.e. the value + * returned by the invocation of + * {@link gnu.java.security.sig.ISignature#sign()} method. In the + * case of a DSS signature this is an array of two MPIs called + * r and s. + * @return the raw bytes of a DSS signature which could be then used as the + * contents of a BIT STRING as per rfc-2459. + * @throws InvalidParameterException if an exception occurs during the + * marshalling process. + */ + public byte[] encodeSignature(Object signature) + { + BigInteger[] rs = (BigInteger[]) signature; + + DERValue derR = new DERValue(DER.INTEGER, rs[0]); + DERValue derS = new DERValue(DER.INTEGER, rs[1]); + + ArrayList dssSigValue = new ArrayList(2); + dssSigValue.add(derR); + dssSigValue.add(derS); + DERValue derDssSigValue = new DERValue(DER.CONSTRUCTED | DER.SEQUENCE, + dssSigValue); + byte[] result; + ByteArrayOutputStream baos = new ByteArrayOutputStream(); + try + { + DERWriter.write(baos, derDssSigValue); + result = baos.toByteArray(); + } + catch (IOException x) + { + InvalidParameterException y = new InvalidParameterException(); + y.initCause(x); + throw y; + } + + return result; + } + + /** + * Decodes a signature as defined in the documentation of this class. + * + * @param input the byte array to unmarshall into a valid DSS signature + * instance; i.e. an array of two MPIs. MUST NOT be null. + * @return an array of two MPIs, r and s in this + * order, decoded from the designated input. + * @throw InvalidParameterException if an exception occurs during the + * unmarshalling process. + */ + public Object decodeSignature(byte[] input) + { + if (input == null) + throw new InvalidParameterException("Input bytes MUST NOT be null"); + + BigInteger r, s; + DERReader der = new DERReader(input); + try + { + DERValue derDssSigValue = der.read(); + DerUtil.checkIsConstructed(derDssSigValue, "Wrong Dss-Sig-Value field"); + + DERValue val = der.read(); + DerUtil.checkIsBigInteger(val, "Wrong R field"); + r = (BigInteger) val.getValue(); + val = der.read(); + DerUtil.checkIsBigInteger(val, "Wrong S field"); + s = (BigInteger) val.getValue(); + } + catch (IOException x) + { + InvalidParameterException y = new InvalidParameterException(); + y.initCause(x); + throw y; + } + + return new BigInteger[] { r, s }; + } +} -- cgit v1.2.3