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Diffstat (limited to 'pki/base/util/src/netscape/security/x509/AlgIdDSA.java')
| -rw-r--r-- | pki/base/util/src/netscape/security/x509/AlgIdDSA.java | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/pki/base/util/src/netscape/security/x509/AlgIdDSA.java b/pki/base/util/src/netscape/security/x509/AlgIdDSA.java new file mode 100644 index 000000000..a3e638ebc --- /dev/null +++ b/pki/base/util/src/netscape/security/x509/AlgIdDSA.java @@ -0,0 +1,178 @@ +// --- BEGIN COPYRIGHT BLOCK --- +// This program 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; version 2 of the License. +// +// This program 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 this program; if not, write to the Free Software Foundation, Inc., +// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. +// +// (C) 2007 Red Hat, Inc. +// All rights reserved. +// --- END COPYRIGHT BLOCK --- +package netscape.security.x509; + +import java.io.IOException; +import java.math.BigInteger; +import java.security.*; +import java.security.interfaces.DSAParams; + +import netscape.security.util.*; + + +/** + * This class identifies DSS/DSA Algorithm variants, which are distinguished + * by using different algorithm parameters <em>P, Q, G</em>. It uses the + * NIST/IETF standard DER encoding. These are used to implement the Digital + * Signature Standard (DSS), FIPS 186. + * + * <P><em><b>NOTE:</b> At this time, DSS/DSA Algorithm IDs must always + * include these parameters. Use of DSS/DSA in modes where parameters are + * either implicit (e.g. a default applicable to a site or a larger scope), + * or are derived from some Certificate Authority's DSS certificate, is + * not currently supported. </em> + * + * @version 1.31 + * @author David Brownell + */ +public final +class AlgIdDSA extends AlgorithmId implements DSAParams +{ + /* + * The three unsigned integer parameters. + */ + private BigInteger p , q, g; + + /** Returns the DSS/DSA parameter "P" */ + public BigInteger getP () { return p; } + + /** Returns the DSS/DSA parameter "Q" */ + public BigInteger getQ () { return q; } + + /** Returns the DSS/DSA parameter "G" */ + public BigInteger getG () { return g; } + + /** + * Default constructor. The OID and parameters must be + * deserialized before this algorithm ID is used. + */ + // XXX deprecated for general use + public AlgIdDSA () {} + + AlgIdDSA (DerValue val) throws IOException + { super(val.getOID()); } + + /** + * Construct an AlgIdDSA from an X.509 encoded byte array. + */ + public AlgIdDSA (byte[] encodedAlg) throws IOException + { super (new DerValue(encodedAlg).getOID()); } + + /** + * Constructs a DSS/DSA Algorithm ID from unsigned integers that + * define the algorithm parameters. Those integers are encoded + * as big-endian byte arrays. + * + * @param p the DSS/DSA paramter "P" + * @param q the DSS/DSA paramter "Q" + * @param g the DSS/DSA paramter "G" + */ + public AlgIdDSA (byte p [], byte q [], byte g []) + throws IOException + { + this (new BigInteger (1, p), + new BigInteger (1, q), + new BigInteger (1, g)); + } + + /** + * Constructs a DSS/DSA Algorithm ID from numeric parameters. + * + * @param p the DSS/DSA paramter "P" + * @param q the DSS/DSA paramter "Q" + * @param g the DSS/DSA paramter "G" + */ + public AlgIdDSA (BigInteger p, BigInteger q, BigInteger g) + { + super (DSA_oid); + + try { + this.p = p; + this.q = q; + this.g = g; + initializeParams (); + + } catch (IOException e) { + /* this should not happen */ + throw new ProviderException ("Construct DSS/DSA Algorithm ID"); + } + } + + /** + * Returns "DSA", indicating the Digital Signature Algorithm (DSA) as + * defined by the Digital Signature Standard (DSS), FIPS 186. + */ + public String getName () + { return "DSA"; } + + + /* + * For algorithm IDs which haven't been created from a DER encoded + * value, "params" must be created. + */ + private void initializeParams () + throws IOException + { + DerOutputStream out = new DerOutputStream (); + + out.putInteger (new BigInt(p.toByteArray())); + out.putInteger (new BigInt(q.toByteArray())); + out.putInteger (new BigInt(g.toByteArray())); + params = new DerValue (DerValue.tag_Sequence,out.toByteArray ()); + } + + /** + * Parses algorithm parameters P, Q, and G. They're found + * in the "params" member, which never needs to be changed. + */ + protected void decodeParams () + throws IOException + { + if (params == null || params.tag != DerValue.tag_Sequence) + throw new IOException("DSA alg parsing error"); + + params.data.reset (); + + this.p = params.data.getInteger ().toBigInteger(); + this.q = params.data.getInteger ().toBigInteger(); + this.g = params.data.getInteger ().toBigInteger(); + + if (params.data.available () != 0) + throw new IOException ("AlgIdDSA params, extra="+ + params.data.available ()); + } + + + /* + * Returns a formatted string describing the parameters. + */ + public String toString () + { return paramsToString (); } + + /* + * Returns a string describing the parameters. + */ + protected String paramsToString () + { + return + "\n p:\n" + (new BigInt(p)).toString() + + "\n q:\n" + (new BigInt(q)).toString() + + "\n g:\n" + (new BigInt(g)).toString() + + "\n"; + } +} |