Subclasses may be used, for example when the algorithm ID has * associated parameters which some code (e.g. code using public keys) needs * to have parsed. Two examples of such algorithms are Diffie-Hellman key * exchange, and the Digital Signature Standard Algorithm (DSS/DSA). * *
The OID constants defined in this class correspond to some widely
* used algorithms, for which conventional string names have been defined.
* This class is not a general repository for OIDs, or for such string names.
* Note that the mappings between algorithm IDs and algorithm names is
* not one-to-one.
*
*
* @author David Brownell
* @author Amit Kapoor
* @author Hemma Prafullchandra
*/
public class AlgorithmId implements Serializable, DerEncoder {
/** use serialVersionUID from JDK 1.1. for interoperability */
@java.io.Serial
private static final long serialVersionUID = 7205873507486557157L;
/**
* The object identifier being used for this algorithm.
*/
private ObjectIdentifier algid;
// The (parsed) parameters
@SuppressWarnings("serial") // Not statically typed as Serializable
private AlgorithmParameters algParams;
/**
* Parameters for this algorithm. These are stored in unparsed
* DER-encoded form; subclasses can be made to automatically parse
* them so there is fast access to these parameters.
*/
protected transient byte[] encodedParams;
/**
* Constructs an algorithm ID which will be initialized
* separately, for example by deserialization.
* @deprecated use one of the other constructors.
*/
@Deprecated
public AlgorithmId() { }
/**
* Constructs a parameterless algorithm ID.
*
* @param oid the identifier for the algorithm
*/
public AlgorithmId(ObjectIdentifier oid) {
algid = oid;
}
/**
* Constructs an algorithm ID with algorithm parameters.
*
* @param oid the identifier for the algorithm.
* @param algparams the associated algorithm parameters, can be null.
* @exception IllegalStateException if algparams is not initialized
* or cannot be encoded
*/
public AlgorithmId(ObjectIdentifier oid, AlgorithmParameters algparams) {
algid = oid;
this.algParams = algparams;
if (algParams != null) {
try {
encodedParams = algParams.getEncoded();
} catch (IOException ioe) {
throw new IllegalStateException(
"AlgorithmParameters not initialized or cannot be decoded",
ioe);
}
}
}
/**
* Constructs an algorithm ID with algorithm parameters as a DerValue.
*
* @param oid the identifier for the algorithm.
* @param params the associated algorithm parameters, can be null.
*/
@SuppressWarnings("this-escape")
public AlgorithmId(ObjectIdentifier oid, DerValue params)
throws IOException {
this.algid = oid;
if (params != null) {
encodedParams = params.toByteArray();
decodeParams();
}
}
protected void decodeParams() throws IOException {
String algidName = getName();
try {
algParams = AlgorithmParameters.getInstance(algidName);
} catch (NoSuchAlgorithmException e) {
/*
* This algorithm parameter type is not supported, so we cannot
* parse the parameters.
*/
algParams = null;
return;
}
// Decode (parse) the parameters
algParams.init(encodedParams.clone());
}
/**
* DER encode this object onto an output stream.
* Implements the DerEncoder interface.
*
* @param out the output stream on which to write the DER encoding.
*/
@Override
public void encode(DerOutputStream out) {
DerOutputStream bytes = new DerOutputStream();
bytes.putOID(algid);
if (encodedParams == null) {
// MessageDigest algorithms usually have a NULL parameters even
// if most RFCs suggested absent.
// RSA key and signature algorithms requires the NULL parameters
// to be present, see A.1 and A.2.4 of RFC 8017.
if (algid.equals(RSAEncryption_oid)
|| algid.equals(MD2_oid)
|| algid.equals(MD5_oid)
|| algid.equals(SHA_oid)
|| algid.equals(SHA224_oid)
|| algid.equals(SHA256_oid)
|| algid.equals(SHA384_oid)
|| algid.equals(SHA512_oid)
|| algid.equals(SHA512_224_oid)
|| algid.equals(SHA512_256_oid)
|| algid.equals(SHA3_224_oid)
|| algid.equals(SHA3_256_oid)
|| algid.equals(SHA3_384_oid)
|| algid.equals(SHA3_512_oid)
|| algid.equals(SHA1withRSA_oid)
|| algid.equals(SHA224withRSA_oid)
|| algid.equals(SHA256withRSA_oid)
|| algid.equals(SHA384withRSA_oid)
|| algid.equals(SHA512withRSA_oid)
|| algid.equals(SHA512$224withRSA_oid)
|| algid.equals(SHA512$256withRSA_oid)
|| algid.equals(MD2withRSA_oid)
|| algid.equals(MD5withRSA_oid)
|| algid.equals(SHA3_224withRSA_oid)
|| algid.equals(SHA3_256withRSA_oid)
|| algid.equals(SHA3_384withRSA_oid)
|| algid.equals(SHA3_512withRSA_oid)) {
bytes.putNull();
}
} else {
bytes.writeBytes(encodedParams);
}
out.write(DerValue.tag_Sequence, bytes);
}
/**
* Returns the DER-encoded X.509 AlgorithmId as a byte array.
*/
public final byte[] encode() {
DerOutputStream out = new DerOutputStream();
encode(out);
return out.toByteArray();
}
/**
* Returns the ISO OID for this algorithm. This is usually converted
* to a string and used as part of an algorithm name, for example
* "OID.1.3.14.3.2.13" style notation. Use the getName
* call when you do not need to ensure cross-system portability
* of algorithm names, or need a user-friendly name.
*/
public final ObjectIdentifier getOID () {
return algid;
}
/**
* Returns a name for the algorithm which can be used by getInstance()
* call of a crypto primitive. The name is usually more intelligible
* to humans than the algorithm's OID, but which won't necessarily
* be comprehensible on other systems. For example, this might
* return a name such as "MD5withRSA" for a signature algorithm on
* some systems. It also returns OID names like "1.2.3.4", when
* no particular name for the algorithm is known. The OID may also be
* recognized by getInstance() calls since an OID is usually defined
* as an alias for an algorithm by the security provider.
*
* In some special cases where the OID does not include enough info
* to return a Java standard algorithm name, an algorithm name
* that includes info on the params is returned:
*
* 1. For ecdsa-with-SHA2 plus hash algorithm (Ex: SHA-256), this method
* returns the "full" signature algorithm (Ex: SHA256withECDSA) directly.
*
* 2. For PBES2, this method returns the "full" cipher name containing the
* KDF and Enc algorithms (Ex: PBEWithHmacSHA256AndAES_256) directly.
*/
public String getName() {
String oidStr = algid.toString();
// first check the list of support oids
KnownOIDs o = KnownOIDs.findMatch(oidStr);
if (o == KnownOIDs.SpecifiedSHA2withECDSA) {
if (encodedParams != null) {
try {
AlgorithmId digestParams =
AlgorithmId.parse(new DerValue(encodedParams));
String digestAlg = digestParams.getName();
return digestAlg.replace("-", "") + "withECDSA";
} catch (IOException e) {
// ignore
}
}
} else if (o == KnownOIDs.PBES2) {
if (algParams != null) {
return algParams.toString();
} else {
// when getName() is called in decodeParams(), algParams is
// null, where AlgorithmParameters.getInstance("PBES2") will
// be used to initialize it.
}
}
if (o != null) {
return o.stdName();
} else {
String n = aliasOidsTable().get(oidStr);
return (n != null) ? n : algid.toString();
}
}
public AlgorithmParameters getParameters() {
return algParams;
}
/**
* Returns the DER encoded parameter, which can then be
* used to initialize java.security.AlgorithmParameters.
*
* Note that this* method should always return a new array as it is called
* directly by the JDK implementation of X509Certificate.getSigAlgParams()
* and X509CRL.getSigAlgParams().
*
* Note: for ecdsa-with-SHA2 plus hash algorithm (Ex: SHA-256), this method
* returns null because {@link #getName()} has already returned the "full"
* signature algorithm (Ex: SHA256withECDSA).
*
* @return DER encoded parameters, or null not present.
*/
public byte[] getEncodedParams() {
return (encodedParams == null ||
algid.toString().equals(KnownOIDs.SpecifiedSHA2withECDSA.value()))
? null
: encodedParams.clone();
}
/**
* Returns true iff the argument indicates the same algorithm
* with the same parameters.
*/
public boolean equals(AlgorithmId other) {
return algid.equals(other.algid) &&
Arrays.equals(encodedParams, other.encodedParams);
}
/**
* Compares this AlgorithmID to another. If algorithm parameters are
* available, they are compared. Otherwise, just the object IDs
* for the algorithm are compared.
*
* @param other preferably an AlgorithmId, else an ObjectIdentifier
*/
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (other instanceof AlgorithmId) {
return equals((AlgorithmId) other);
} else if (other instanceof ObjectIdentifier) {
return equals((ObjectIdentifier) other);
} else {
return false;
}
}
/**
* Compares two algorithm IDs for equality. Returns true iff
* they are the same algorithm, ignoring algorithm parameters.
*/
public final boolean equals(ObjectIdentifier id) {
return algid.equals((Object)id);
}
/**
* {@return a hashcode for this AlgorithmId}
*/
@Override
public int hashCode() {
int hashCode = algid.hashCode();
hashCode = 31 * hashCode + Arrays.hashCode(encodedParams);
return hashCode;
}
/**
* Provides a human-readable description of the algorithm parameters.
* This may be redefined by subclasses which parse those parameters.
*/
protected String paramsToString() {
if (encodedParams == null) {
return "";
} else if (algParams != null) {
return ", " + algParams.toString();
} else {
return ", params unparsed";
}
}
/**
* Returns a string describing the algorithm and its parameters.
*/
@Override
public String toString() {
return getName() + paramsToString();
}
/**
* Parse (unmarshal) an ID from a DER sequence input value. This form
* parsing might be used when expanding a value which has already been
* partially unmarshaled as a set or sequence member.
*
* @exception IOException on error.
* @param val the input value, which contains the algid and, if
* there are any parameters, those parameters.
* @return an ID for the algorithm. If the system is configured
* appropriately, this may be an instance of a class
* with some kind of special support for this algorithm.
* In that case, you may "narrow" the type of the ID.
*/
public static AlgorithmId parse(DerValue val) throws IOException {
if (val.tag != DerValue.tag_Sequence) {
throw new IOException("algid parse error, not a sequence");
}
/*
* Get the algorithm ID and any parameters.
*/
ObjectIdentifier algid;
DerValue params;
DerInputStream in = val.toDerInputStream();
algid = in.getOID();
if (in.available() == 0) {
params = null;
} else {
params = in.getDerValue();
if (params.tag == DerValue.tag_Null) {
if (params.length() != 0) {
throw new IOException("invalid NULL");
}
params = null;
}
if (in.available() != 0) {
throw new IOException("Invalid AlgorithmIdentifier: extra data");
}
}
return new AlgorithmId(algid, params);
}
/**
* Returns one of the algorithm IDs most commonly associated
* with this algorithm name.
*
* @param algname the name being used
* @deprecated use the short get form of this method.
* @exception NoSuchAlgorithmException on error.
*/
@Deprecated
public static AlgorithmId getAlgorithmId(String algname)
throws NoSuchAlgorithmException {
return get(algname);
}
/**
* Returns one of the algorithm IDs most commonly associated
* with this algorithm name.
*
* @param algname the name being used
* @exception NoSuchAlgorithmException on error.
*/
public static AlgorithmId get(String algname)
throws NoSuchAlgorithmException {
ObjectIdentifier oid;
try {
oid = algOID(algname);
} catch (IOException ioe) {
throw new NoSuchAlgorithmException
("Invalid ObjectIdentifier " + algname);
}
if (oid == null) {
throw new NoSuchAlgorithmException
("unrecognized algorithm name: " + algname);
}
return new AlgorithmId(oid);
}
/**
* Returns one of the algorithm IDs most commonly associated
* with this algorithm parameters.
*
* @param algparams the associated algorithm parameters.
* @exception NoSuchAlgorithmException on error.
* @exception IllegalStateException if algparams is not initialized
* or cannot be encoded
*/
public static AlgorithmId get(AlgorithmParameters algparams)
throws NoSuchAlgorithmException {
ObjectIdentifier oid;
String algname = algparams.getAlgorithm();
try {
oid = algOID(algname);
} catch (IOException ioe) {
throw new NoSuchAlgorithmException
("Invalid ObjectIdentifier " + algname);
}
if (oid == null) {
throw new NoSuchAlgorithmException
("unrecognized algorithm name: " + algname);
}
return new AlgorithmId(oid, algparams);
}
/*
* Translates from some common algorithm names to the
* OID with which they're usually associated ... this mapping
* is the reverse of the one below, except in those cases
* where synonyms are supported or where a given algorithm
* is commonly associated with multiple OIDs.
*
* XXX This method needs to be enhanced so that we can also pass the
* scope of the algorithm name to it, e.g., the algorithm name "DSA"
* may have a different OID when used as a "Signature" algorithm than when
* used as a "KeyPairGenerator" algorithm.
*/
private static ObjectIdentifier algOID(String name) throws IOException {
if (name.startsWith("OID.")) {
name = name.substring("OID.".length());
}
KnownOIDs k = KnownOIDs.findMatch(name);
if (k != null) {
return ObjectIdentifier.of(k);
}
// unknown algorithm oids
if (!name.contains(".")) {
// see if there is a matching oid string alias mapping from
// 3rd party providers
name = name.toUpperCase(Locale.ENGLISH);
String oidStr = aliasOidsTable().get(name);
if (oidStr != null) {
return ObjectIdentifier.of(oidStr);
} return null;
} else {
return ObjectIdentifier.of(name);
}
}
// oid string cache indexed by algorithm name and oid strings
private static volatile Map