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package sun.security.rsa;

import java.io.IOException;
import java.security.*;
import java.security.spec.*;
import sun.security.util.ObjectIdentifier;
import sun.security.x509.AlgorithmId;

Utility class for SunRsaSign provider. Currently used by RSAKeyPairGenerator and RSAKeyFactory.
Since:8
/** * Utility class for SunRsaSign provider. * Currently used by RSAKeyPairGenerator and RSAKeyFactory. * * @since 8 */
public class RSAUtil { public enum KeyType { RSA ("RSA"), PSS ("RSASSA-PSS") ; private final String algo; KeyType(String keyAlgo) { this.algo = keyAlgo; } public String keyAlgo() { return algo; } public static KeyType lookup(String name) throws InvalidKeyException, ProviderException { if (name == null) { throw new InvalidKeyException("Null key algorithm"); } for (KeyType kt : KeyType.values()) { if (kt.keyAlgo().equalsIgnoreCase(name)) { return kt; } } // no match throw new ProviderException("Unsupported algorithm " + name); } } public static void checkParamsAgainstType(KeyType type, AlgorithmParameterSpec paramSpec) throws ProviderException { switch (type) { case RSA: if (paramSpec != null) { throw new ProviderException("null params expected for " + type.keyAlgo()); } break; case PSS: if ((paramSpec != null) && !(paramSpec instanceof PSSParameterSpec)) { throw new ProviderException ("PSSParmeterSpec expected for " + type.keyAlgo()); } break; default: throw new ProviderException ("Unsupported RSA algorithm " + type); } } public static AlgorithmId createAlgorithmId(KeyType type, AlgorithmParameterSpec paramSpec) throws ProviderException { checkParamsAgainstType(type, paramSpec); ObjectIdentifier oid = null; AlgorithmParameters params = null; try { switch (type) { case RSA: oid = AlgorithmId.RSAEncryption_oid; break; case PSS: if (paramSpec != null) { params = AlgorithmParameters.getInstance(type.keyAlgo()); params.init(paramSpec); } oid = AlgorithmId.RSASSA_PSS_oid; break; default: throw new ProviderException ("Unsupported RSA algorithm " + type); } AlgorithmId result; if (params == null) { result = new AlgorithmId(oid); } else { result = new AlgorithmId(oid, params); } return result; } catch (NoSuchAlgorithmException | InvalidParameterSpecException e) { // should not happen throw new ProviderException(e); } } public static AlgorithmParameterSpec getParamSpec(AlgorithmId algid) throws ProviderException { if (algid == null) { throw new ProviderException("AlgorithmId should not be null"); } return getParamSpec(algid.getParameters()); } public static AlgorithmParameterSpec getParamSpec(AlgorithmParameters params) throws ProviderException { if (params == null) return null; try { String algName = params.getAlgorithm(); KeyType type = KeyType.lookup(algName); Class<? extends AlgorithmParameterSpec> specCls; switch (type) { case RSA: throw new ProviderException("No params accepted for " + type.keyAlgo()); case PSS: specCls = PSSParameterSpec.class; break; default: throw new ProviderException("Unsupported RSA algorithm: " + algName); } return params.getParameterSpec(specCls); } catch (ProviderException pe) { // pass it up throw pe; } catch (Exception e) { throw new ProviderException(e); } } }