/*******************************************************************************
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package at.gv.egiz.eaaf.modules.pvp2.impl.utils;

import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.interfaces.ECPrivateKey;
import java.security.interfaces.RSAPrivateKey;

import org.apache.commons.lang3.StringUtils;
import org.opensaml.xml.security.credential.Credential;
import org.opensaml.xml.security.credential.UsageType;
import org.opensaml.xml.security.x509.X509Credential;
import org.opensaml.xml.signature.Signature;
import org.opensaml.xml.signature.SignatureConstants;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import at.gv.egiz.eaaf.core.exceptions.EAAFException;
import at.gv.egiz.eaaf.core.impl.utils.KeyStoreUtils;
import at.gv.egiz.eaaf.modules.pvp2.exception.CredentialsNotAvailableException;
import at.gv.egiz.eaaf.modules.pvp2.impl.opensaml.KeyStoreX509CredentialAdapter;

public abstract class AbstractCredentialProvider {
	
	private static final Logger log = LoggerFactory.getLogger(AbstractCredentialProvider.class);
	
	private KeyStore keyStore = null;
	
	/**
	 * Get a friendlyName for this keyStore implementation
	 * This friendlyName is used for logging
	 * 
	 * @return keyStore friendlyName
	 */
	public abstract String getFriendlyName();
	
	/**
	 * Get KeyStore
	 * 
	 * @return URL to the keyStore
	 * @throws EAAFException 
	 */
	public abstract String getKeyStoreFilePath() throws EAAFException;
	
	/**
	 * Get keyStore password
	 * 
	 * @return Password of the keyStore
	 */
	public abstract String getKeyStorePassword();
	
	/**
	 * Get alias of key for metadata signing
	 * 
	 * @return key alias
	 */
	public abstract String getMetadataKeyAlias();
	
	/**
	 * Get password of key for metadata signing
	 * 
	 * @return key password
	 */
	public abstract String getMetadataKeyPassword();
	
	/**
	 * Get alias of key for request/response signing
	 * 
	 * @return key alias
	 */
	public abstract String getSignatureKeyAlias();
	
	/**
	 * Get password of key for request/response signing
	 * 
	 * @return key password
	 */
	public abstract String getSignatureKeyPassword();
	
	/**
	 * Get alias of key for IDP response encryption
	 * 
	 * @return key alias
	 */
	public abstract String getEncryptionKeyAlias();
	
	/**
	 * Get password of key for IDP response encryption
	 * 
	 * @return key password
	 */
	public abstract String getEncryptionKeyPassword();
	
	
	public X509Credential getIDPMetaDataSigningCredential()
			throws CredentialsNotAvailableException {
		try {
			
			if (keyStore == null)
				keyStore = KeyStoreUtils.loadKeyStore(getKeyStoreFilePath(), 
						getKeyStorePassword());

			KeyStoreX509CredentialAdapter credentials = new KeyStoreX509CredentialAdapter(
					keyStore, getMetadataKeyAlias(), getMetadataKeyPassword().toCharArray());

			credentials.setUsageType(UsageType.SIGNING);
			if (credentials.getPrivateKey() == null && credentials.getSecretKey() == null) {
				log.error(getFriendlyName() + " Metadata Signing credentials is not found or contains no PrivateKey.");
				throw new CredentialsNotAvailableException("config.27", new Object[]{getFriendlyName() + " Assertion Signing credentials (Alias: "
						+ getMetadataKeyAlias() + ") is not found or contains no PrivateKey."});
				
			}
			return credentials;
		} catch (Exception e) {
			log.error("Failed to generate " + getFriendlyName() + " Metadata Signing credentials");
			e.printStackTrace();
			throw new CredentialsNotAvailableException("config.27", new Object[]{e.getMessage()}, e);
		}
	}

	public X509Credential getIDPAssertionSigningCredential()
			throws CredentialsNotAvailableException {
		try {
			if (keyStore == null)
				keyStore = KeyStoreUtils.loadKeyStore(getKeyStoreFilePath(), 
						getKeyStorePassword());

			KeyStoreX509CredentialAdapter credentials = new KeyStoreX509CredentialAdapter(
					keyStore, getSignatureKeyAlias(), getSignatureKeyPassword().toCharArray());
			
			credentials.setUsageType(UsageType.SIGNING);
			if (credentials.getPrivateKey() == null && credentials.getSecretKey() == null) {
				log.error(getFriendlyName() + " Assertion Signing credentials is not found or contains no PrivateKey.");
				throw new CredentialsNotAvailableException("config.27", new Object[]{getFriendlyName() + " Assertion Signing credentials (Alias: "
						+ getSignatureKeyAlias() + ") is not found or contains no PrivateKey."});
				
			}
			
			return (X509Credential) credentials;
		} catch (Exception e) {
			log.error("Failed to generate " + getFriendlyName() + " Assertion Signing credentials");
			e.printStackTrace();
			throw new CredentialsNotAvailableException("config.27", new Object[]{e.getMessage()}, e);
		}
	}
	
	public X509Credential getIDPAssertionEncryptionCredential()
			throws CredentialsNotAvailableException {
		try {
			if (keyStore == null)
				keyStore = KeyStoreUtils.loadKeyStore(getKeyStoreFilePath(), 
						getKeyStorePassword());

			//if no encryption key is configured return null
			if (StringUtils.isEmpty(getEncryptionKeyAlias()))
				return null;
			
			KeyStoreX509CredentialAdapter credentials = new KeyStoreX509CredentialAdapter(
					keyStore, getEncryptionKeyAlias(), getEncryptionKeyPassword().toCharArray());
			
			credentials.setUsageType(UsageType.ENCRYPTION);
			
			if (credentials.getPrivateKey() == null && credentials.getSecretKey() == null) {
				log.error(getFriendlyName() + " Assertion Encryption credentials is not found or contains no PrivateKey.");
				throw new CredentialsNotAvailableException("config.27", new Object[]{getFriendlyName() + " Assertion Encryption credentials (Alias: "
						+ getEncryptionKeyAlias() + ") is not found or contains no PrivateKey."});
				
			}
			
			return (X509Credential) credentials;
			
		} catch (Exception e) {
			log.error("Failed to generate " + getFriendlyName() + " Assertion Encryption credentials");
			e.printStackTrace();
			throw new CredentialsNotAvailableException("config.27", new Object[]{e.getMessage()}, e);
		}
	}
	
	public static Signature getIDPSignature(Credential credentials) {		
		PrivateKey privatekey = credentials.getPrivateKey();		
		Signature signer = SAML2Utils.createSAMLObject(Signature.class);
		
		if (privatekey instanceof RSAPrivateKey) {
			signer.setSignatureAlgorithm(SignatureConstants.ALGO_ID_SIGNATURE_RSA_SHA256);
			
		} else if (privatekey instanceof ECPrivateKey) {
			signer.setSignatureAlgorithm(SignatureConstants.ALGO_ID_SIGNATURE_ECDSA_SHA256);

		} else {
			log.warn("Could NOT evaluate the Private-Key type from " + credentials.getEntityId() + " credential.");
			
			
		}

		signer.setCanonicalizationAlgorithm(SignatureConstants.ALGO_ID_C14N_EXCL_OMIT_COMMENTS);		
		signer.setSigningCredential(credentials);
		return signer;
		
	}
}