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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package java.security.spec;
/**
* This immutable class specifies the set of parameters used for
* generating DSA parameters as specified in
* <a href="http://csrc.nist.gov/publications/fips/fips186-3/fips_186-3.pdf">FIPS 186-3 Digital Signature Standard (DSS)</a>.
*
* @see AlgorithmParameterSpec
*
* @since 8
*/
public final class DSAGenParameterSpec implements AlgorithmParameterSpec {
private final int pLen;
private final int qLen;
private final int seedLen;
/**
* Creates a domain parameter specification for DSA parameter
* generation using {@code primePLen} and {@code subprimeQLen}.
* The value of {@code subprimeQLen} is also used as the default
* length of the domain parameter seed in bits.
* @param primePLen the desired length of the prime P in bits.
* @param subprimeQLen the desired length of the sub-prime Q in bits.
* @exception IllegalArgumentException if {@code primePLen}
* or {@code subprimeQLen} is illegal per the specification of
* FIPS 186-3.
*/
public DSAGenParameterSpec(int primePLen, int subprimeQLen) {
this(primePLen, subprimeQLen, subprimeQLen);
}
/**
* Creates a domain parameter specification for DSA parameter
* generation using {@code primePLen}, {@code subprimeQLen},
* and {@code seedLen}.
* @param primePLen the desired length of the prime P in bits.
* @param subprimeQLen the desired length of the sub-prime Q in bits.
* @param seedLen the desired length of the domain parameter seed in bits,
* shall be equal to or greater than {@code subprimeQLen}.
* @exception IllegalArgumentException if {@code primePLenLen},
* {@code subprimeQLen}, or {@code seedLen} is illegal per the
* specification of FIPS 186-3.
*/
public DSAGenParameterSpec(int primePLen, int subprimeQLen, int seedLen) {
switch (primePLen) {
case 1024:
if (subprimeQLen != 160) {
throw new IllegalArgumentException
("subprimeQLen must be 160 when primePLen=1024");
}
break;
case 2048:
if (subprimeQLen != 224 && subprimeQLen != 256) {
throw new IllegalArgumentException
("subprimeQLen must be 224 or 256 when primePLen=2048");
}
break;
case 3072:
if (subprimeQLen != 256) {
throw new IllegalArgumentException
("subprimeQLen must be 256 when primePLen=3072");
}
break;
default:
throw new IllegalArgumentException
("primePLen must be 1024, 2048, or 3072");
}
if (seedLen < subprimeQLen) {
throw new IllegalArgumentException
("seedLen must be equal to or greater than subprimeQLen");
}
this.pLen = primePLen;
this.qLen = subprimeQLen;
this.seedLen = seedLen;
}
/**
* Returns the desired length of the prime P of the
* to-be-generated DSA domain parameters in bits.
* @return the length of the prime P.
*/
public int getPrimePLength() {
return pLen;
}
/**
* Returns the desired length of the sub-prime Q of the
* to-be-generated DSA domain parameters in bits.
* @return the length of the sub-prime Q.
*/
public int getSubprimeQLength() {
return qLen;
}
/**
* Returns the desired length of the domain parameter seed in bits.
* @return the length of the domain parameter seed.
*/
public int getSeedLength() {
return seedLen;
}
}