EncryptedPrivateKeyInfo ASN.1
* type as specified in PKCS #8 -
* Private-Key Information Syntax Standard.
*
* The ASN.1 type EncryptedPrivateKeyInfo is:
*
*
* EncryptedPrivateKeyInfo ::= SEQUENCE {
* encryptionAlgorithm EncryptionAlgorithmIdentifier,
* encryptedData EncryptedData }
*
* EncryptionAlgorithmIdentifier ::= AlgorithmIdentifier
*
* EncrytpedData ::= OCTET STRING
*
* AlgorithmIdentifier ::= SEQUENCE {
* algorithm OBJECT IDENTIFIER,
* parameters ANY DEFINED BY algorithm OPTIONAL }
*
*
* @author Casey Marshall (csm@gnu.org)
* @since 1.4
* @see java.security.spec.PKCS8EncodedKeySpec
*/
public class EncryptedPrivateKeyInfo
{
// Fields.
// ------------------------------------------------------------------------
/** The encrypted data. */
private byte[] encryptedData;
/** The encoded, encrypted key. */
private byte[] encoded;
/** The OID of the encryption algorithm. */
private OID algOid;
/** The encryption algorithm name. */
private String algName;
/** The encryption algorithm's parameters. */
private AlgorithmParameters params;
/** The encoded ASN.1 algorithm parameters. */
private byte[] encodedParams;
// Constructors.
// ------------------------------------------------------------------------
/**
* Create a new EncryptedPrivateKeyInfo object from raw
* encrypted data and the parameters used for encryption.
*
* The encryptedData array is cloned.
*
* @param params The encryption algorithm parameters.
* @param encryptedData The encrypted key data.
* @throws java.lang.IllegalArgumentException If the
* encryptedData array is empty (zero-length).
* @throws java.security.NoSuchAlgorithmException If the algorithm
* specified in the parameters is not supported.
* @throws java.lang.NullPointerException If encryptedData
* is null.
*/
public EncryptedPrivateKeyInfo(AlgorithmParameters params,
byte[] encryptedData)
throws IllegalArgumentException, NoSuchAlgorithmException
{
if (encryptedData.length == 0)
{
throw new IllegalArgumentException("0-length encryptedData");
}
this.params = params;
algName = params.getAlgorithm ();
algOid = getOid (algName);
this.encryptedData = (byte[]) encryptedData.clone();
}
/**
* Create a new EncryptedPrivateKeyInfo from an encoded
* representation, parsing the ASN.1 sequence.
*
* @param encoded The encoded info.
* @throws java.io.IOException If parsing the encoded data fails.
* @throws java.lang.NullPointerException If encoded is
* null.
*/
public EncryptedPrivateKeyInfo(byte[] encoded)
throws IOException
{
this.encoded = (byte[]) encoded.clone();
decode();
}
/**
* Create a new EncryptedPrivateKeyInfo from the cipher
* name and the encrytpedData.
*
*
The encryptedData array is cloned.
*
* @param algName The name of the algorithm (as an object identifier).
* @param encryptedData The encrypted key data.
* @throws java.lang.IllegalArgumentException If the
* encryptedData array is empty (zero-length).
* @throws java.security.NoSuchAlgorithmException If algName is not
* the name of a supported algorithm.
* @throws java.lang.NullPointerException If encryptedData
* is null.
*/
public EncryptedPrivateKeyInfo(String algName, byte[] encryptedData)
throws IllegalArgumentException, NoSuchAlgorithmException,
NullPointerException
{
if (encryptedData.length == 0)
{
throw new IllegalArgumentException("0-length encryptedData");
}
this.algName = algName.toString (); // do NP check
this.algOid = getOid (algName);
this.encryptedData = (byte[]) encryptedData.clone();
}
/**
* Return the OID for the given cipher name.
*
* @param str The string.
* @throws NoSuchAlgorithmException If the OID is not known.
*/
private static OID getOid (final String str)
throws NoSuchAlgorithmException
{
if (str.equalsIgnoreCase ("DSA"))
{
return new OID ("1.2.840.10040.4.3");
}
// FIXME add more
try
{
return new OID (str);
}
catch (Throwable t)
{
}
throw new NoSuchAlgorithmException ("cannot determine OID for '" + str + "'");
}
// Instance methods.
// ------------------------------------------------------------------------
/**
* Return the name of the cipher used to encrypt this key.
*
* @return The algorithm name.
*/
public String getAlgName()
{
return algOid.toString();
}
public AlgorithmParameters getAlgParameters()
{
if (params == null && encodedParams != null)
{
try
{
params = AlgorithmParameters.getInstance(getAlgName());
params.init(encodedParams);
}
catch (NoSuchAlgorithmException ignore)
{
// FIXME throw exception?
}
catch (IOException ignore)
{
}
}
return params;
}
public synchronized byte[] getEncoded() throws IOException
{
if (encoded == null) encode();
return (byte[]) encoded.clone();
}
public byte[] getEncryptedData()
{
return encryptedData;
}
public PKCS8EncodedKeySpec getKeySpec(Cipher cipher)
throws InvalidKeySpecException
{
try
{
return new PKCS8EncodedKeySpec(cipher.doFinal(encryptedData));
}
catch (Exception x)
{
throw new InvalidKeySpecException(x.toString());
}
}
// Own methods.
// -------------------------------------------------------------------------
private void decode() throws IOException
{
DERReader der = new DERReader(encoded);
DERValue val = der.read();
if (val.getTag() != DER.SEQUENCE)
throw new IOException("malformed EncryptedPrivateKeyInfo");
val = der.read();
if (val.getTag() != DER.SEQUENCE)
throw new IOException("malformed AlgorithmIdentifier");
int algpLen = val.getLength();
DERValue oid = der.read();
if (oid.getTag() != DER.OBJECT_IDENTIFIER)
throw new IOException("malformed AlgorithmIdentifier");
algOid = (OID) oid.getValue();
if (algpLen == 0)
{
val = der.read();
if (val.getTag() != 0)
{
encodedParams = val.getEncoded();
der.read();
}
}
else if (oid.getEncodedLength() < val.getLength())
{
val = der.read();
encodedParams = val.getEncoded();
}
val = der.read();
if (val.getTag() != DER.OCTET_STRING)
throw new IOException("malformed AlgorithmIdentifier");
encryptedData = (byte[]) val.getValue();
}
private void encode() throws IOException
{
List algId = new ArrayList(2);
algId.add(new DERValue(DER.OBJECT_IDENTIFIER, algOid));
getAlgParameters();
if (params != null)
{
algId.add (DERReader.read (params.getEncoded()));
}
else
{
algId.add (new DERValue (DER.NULL, null));
}
List epki = new ArrayList(2);
epki.add(new DERValue(DER.CONSTRUCTED|DER.SEQUENCE, algId));
epki.add(new DERValue(DER.OCTET_STRING, encryptedData));
encoded = new DERValue(DER.CONSTRUCTED|DER.SEQUENCE, epki).getEncoded();
}
}