Class ProviderKey

impl/src/main/java/io/jsonwebtoken/impl/security/ProviderKey.java:24–76

import java.security.Provider;

public class ProviderKey<T extends Key> implements Key, KeySupplier<T> {

    private final T key;

    private final Provider provider;

    public static Provider getProvider(Key key, Provider backup) {
        if (key instanceof ProviderKey<?>) {
            ProviderKey<?> pkey = (ProviderKey<?>) key;
            return Assert.stateNotNull(pkey.getProvider(), "ProviderKey provider can never be null.");
        }
        return backup;
    }

    @SuppressWarnings("unchecked")
    public static <K extends Key> K getKey(K key) {
        return key instanceof ProviderKey ? ((ProviderKey<K>) key).getKey() : key;
    }

    ProviderKey(Provider provider, T key) {
        this.provider = Assert.notNull(provider, "Provider cannot be null.");
        this.key = Assert.notNull(key, "Key argument cannot be null.");
        if (key instanceof ProviderKey<?>) {
            String msg = "Nesting not permitted.";
            throw new IllegalArgumentException(msg);
        }
    }

    @Override
    public T getKey() {
        return this.key;
    }

    @Override
    public String getAlgorithm() {
        return this.key.getAlgorithm();
    }

    @Override
    public String getFormat() {
        return this.key.getFormat();
    }

    @Override
    public byte[] getEncoded() {
        return this.key.getEncoded();
    }

    public final Provider getProvider() {
        return this.provider;
    }

}