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package javax.crypto.spec;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.MGF1ParameterSpec;
/**
* This class specifies the set of parameters used with OAEP Padding,
* as defined in the
* PKCS#1 v2.2 standard.
*
* Its ASN.1 definition in PKCS#1 standard is described below:
*
* RSAES-OAEP-params ::= SEQUENCE {
* hashAlgorithm [0] HashAlgorithm DEFAULT sha1,
* maskGenAlgorithm [1] MaskGenAlgorithm DEFAULT mgf1SHA1,
* pSourceAlgorithm [2] PSourceAlgorithm DEFAULT pSpecifiedEmpty
* }
*
* where
*
* HashAlgorithm ::= AlgorithmIdentifier {
* {OAEP-PSSDigestAlgorithms}
* }
* MaskGenAlgorithm ::= AlgorithmIdentifier { {PKCS1MGFAlgorithms} }
* PSourceAlgorithm ::= AlgorithmIdentifier {
* {PKCS1PSourceAlgorithms}
* }
*
* OAEP-PSSDigestAlgorithms ALGORITHM-IDENTIFIER ::= {
* { OID id-sha1 PARAMETERS NULL }|
* { OID id-sha224 PARAMETERS NULL }|
* { OID id-sha256 PARAMETERS NULL }|
* { OID id-sha384 PARAMETERS NULL }|
* { OID id-sha512 PARAMETERS NULL }|
* { OID id-sha512-224 PARAMETERS NULL }|
* { OID id-sha512-256 PARAMETERS NULL },
* ... -- Allows for future expansion --
* }
* PKCS1MGFAlgorithms ALGORITHM-IDENTIFIER ::= {
* { OID id-mgf1 PARAMETERS HashAlgorithm },
* ... -- Allows for future expansion --
* }
* PKCS1PSourceAlgorithms ALGORITHM-IDENTIFIER ::= {
* { OID id-pSpecified PARAMETERS EncodingParameters },
* ... -- Allows for future expansion --
* }
* EncodingParameters ::= OCTET STRING(SIZE(0..MAX))
*
*
* @spec https://www.rfc-editor.org/info/rfc8017
* RFC 8017: PKCS #1: RSA Cryptography Specifications Version 2.2
* @see java.security.spec.MGF1ParameterSpec
* @see PSource
*
* @author Valerie Peng
*
* @since 1.5
*/
public class OAEPParameterSpec implements AlgorithmParameterSpec {
private final String mdName;
private final String mgfName;
private final AlgorithmParameterSpec mgfSpec;
private final PSource pSrc;
/**
* The OAEP parameter set with all default values, i.e. "SHA-1" as message
* digest algorithm, "MGF1" as mask generation function (mgf) algorithm,
* {@code MGF1ParameterSpec.SHA1} as parameters for the mask generation
* function, and {@code PSource.PSpecified.DEFAULT} as the source of the
* encoding input.
*
* @deprecated This field uses the default values defined in the PKCS #1
* standard. Some of these defaults are no longer recommended due
* to advances in cryptanalysis -- see
* Appendix B.1 of PKCS #1
* for more details. Thus, it is recommended to create
* a new {@code OAEPParameterSpec} with the desired parameter values
* using the
* {@link #OAEPParameterSpec(String, String, AlgorithmParameterSpec, PSource)} constructor.
*
*/
@Deprecated(since="19")
public static final OAEPParameterSpec DEFAULT = new OAEPParameterSpec(
"SHA-1", "MGF1", MGF1ParameterSpec.SHA1,
PSource.PSpecified.DEFAULT);
/**
* Constructs a parameter set for OAEP padding as defined in
* the PKCS #1 standard using the specified message digest
* algorithm {@code mdName}, mask generation function
* algorithm {@code mgfName}, parameters for the mask
* generation function {@code mgfSpec}, and source of
* the encoding input P {@code pSrc}.
*
* @param mdName the algorithm name for the message digest
* @param mgfName the algorithm name for the mask generation function
* @param mgfSpec the parameters for the mask generation function;
* if {@code null} is specified, {@code null} will be returned by
* {@link #getMGFParameters()}
* @param pSrc the source of the encoding input P
* @throws NullPointerException if {@code mdName},
* {@code mgfName}, or {@code pSrc} is {@code null}
*/
public OAEPParameterSpec(String mdName, String mgfName,
AlgorithmParameterSpec mgfSpec,
PSource pSrc) {
if (mdName == null) {
throw new NullPointerException("digest algorithm is null");
}
if (mgfName == null) {
throw new NullPointerException("mask generation function " +
"algorithm is null");
}
if (pSrc == null) {
throw new NullPointerException("source of the encoding input " +
"is null");
}
this.mdName = mdName;
this.mgfName = mgfName;
this.mgfSpec = mgfSpec;
this.pSrc = pSrc;
}
/**
* Returns the message digest algorithm name.
*
* @return the message digest algorithm name.
*/
public String getDigestAlgorithm() {
return mdName;
}
/**
* Returns the mask generation function algorithm name.
*
* @return the mask generation function algorithm name.
*/
public String getMGFAlgorithm() {
return mgfName;
}
/**
* Returns the parameters for the mask generation function.
*
* @return the parameters for the mask generation function.
*/
public AlgorithmParameterSpec getMGFParameters() {
return mgfSpec;
}
/**
* Returns the source of encoding input P.
*
* @return the source of encoding input P.
*/
public PSource getPSource() {
return pSrc;
}
}