java/6 : sun/security/x509/AlgorithmId.java

AlgorithmId
https://openjdk.java.net/
GPLv2 + Classpath Exception
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
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 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package sun.security.x509;

import java.io.*;
import java.util.*;
import java.security.*;

import sun.security.util.*;


This class identifies algorithms, such as cryptographic transforms, each
of which may be associated with parameters.  Instances of this base class
are used when this runtime environment has no special knowledge of the
algorithm type, and may also be used in other cases.  Equivalence is
defined according to OID and (where relevant) parameters.
Subclasses may be used, for example when 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, Amit Kapoor, Hemma Prafullchandra/**
 * This class identifies algorithms, such as cryptographic transforms, each
 * of which may be associated with parameters.  Instances of this base class
 * are used when this runtime environment has no special knowledge of the
 * algorithm type, and may also be used in other cases.  Equivalence is
 * defined according to OID and (where relevant) parameters.
 *
 * <P>Subclasses may be used, for example when 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).
 *
 * <P>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 /** use serialVersionUID from JDK 1.1. for interoperability */
    private static final long serialVersionUID = 7205873507486557157L;

    The object identitifer being used for this algorithm.
/**
     * The object identitifer being used for this algorithm.
     */
    private ObjectIdentifier algid;

    // The (parsed) parameters
    private AlgorithmParameters algParams;
    private boolean constructedFromDer = true;

    Parameters for this algorithm.  These are stored in unparsed
DER-encoded form; subclasses can be made to automaticaly parse
them so there is fast access to these parameters.
/**
     * Parameters for this algorithm.  These are stored in unparsed
     * DER-encoded form; subclasses can be made to automaticaly parse
     * them so there is fast access to these parameters.
     */
    protected DerValue          params;


    Constructs an algorithm ID which will be initialized
separately, for example by deserialization.
Deprecated: use one of the other constructors./**
     * 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.
Params: oid – the identifier for the algorithm/**
     * 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.
Params: oid – the identifier for the algorithm.
algparams – the associated algorithm parameters./**
     * Constructs an algorithm ID with algorithm parameters.
     *
     * @param oid the identifier for the algorithm.
     * @param algparams the associated algorithm parameters.
     */
    public AlgorithmId(ObjectIdentifier oid, AlgorithmParameters algparams) {
        algid = oid;
        algParams = algparams;
        constructedFromDer = false;
    }

    private AlgorithmId(ObjectIdentifier oid, DerValue params)
            throws IOException {
        this.algid = oid;
        this.params = params;
        if (this.params != null) {
            decodeParams();
        }
    }

    protected void decodeParams() throws IOException {
        String algidString = algid.toString();
        try {
            algParams = AlgorithmParameters.getInstance(algidString);
        } catch (NoSuchAlgorithmException e) {
            try {
                // Try the internal EC code so that we can fully parse EC
                // keys even if the provider is not registered.
                // This code can go away once we have EC in the SUN provider.
                algParams = AlgorithmParameters.getInstance(algidString,
                                sun.security.ec.ECKeyFactory.ecInternalProvider);
            } catch (NoSuchAlgorithmException ee) {
                /*
                 * This algorithm parameter type is not supported, so we cannot
                 * parse the parameters.
                 */
                algParams = null;
                return;
            }
        }
        // Decode (parse) the parameters
        algParams.init(params.toByteArray());
    }

    Marshal a DER-encoded "AlgorithmID" sequence on the DER stream.
/**
     * Marshal a DER-encoded "AlgorithmID" sequence on the DER stream.
     */
    public final void encode(DerOutputStream out) throws IOException {
        derEncode(out);
    }

    DER encode this object onto an output stream.
Implements the DerEncoder interface.
Params: out – 
the output stream on which to write the DER encoding.
Throws: IOException – on encoding error./**
     * DER encode this object onto an output stream.
     * Implements the <code>DerEncoder</code> interface.
     *
     * @param out
     * the output stream on which to write the DER encoding.
     *
     * @exception IOException on encoding error.
     */
    public void derEncode (OutputStream out) throws IOException {
        DerOutputStream bytes = new DerOutputStream();
        DerOutputStream tmp = new DerOutputStream();

        bytes.putOID(algid);
        // Setup params from algParams since no DER encoding is given
        if (constructedFromDer == false) {
            if (algParams != null) {
                params = new DerValue(algParams.getEncoded());
            } else {
                params = null;
            }
        }
        if (params == null) {
            // Changes backed out for compatibility with Solaris

            // Several AlgorithmId should omit the whole parameter part when
            // it's NULL. They are ---
            // rfc3370 2.1: Implementations SHOULD generate SHA-1
            // AlgorithmIdentifiers with absent parameters.
            // rfc3447 C1: When id-sha1, id-sha224, id-sha256, id-sha384 and
            // id-sha512 are used in an AlgorithmIdentifier the parameters
            // (which are optional) SHOULD be omitted.
            // rfc3279 2.3.2: The id-dsa algorithm syntax includes optional
            // domain parameters... When omitted, the parameters component
            // MUST be omitted entirely
            // rfc3370 3.1: When the id-dsa-with-sha1 algorithm identifier
            // is used, the AlgorithmIdentifier parameters field MUST be absent.
            /*if (
                algid.equals((Object)SHA_oid) ||
                algid.equals((Object)SHA224_oid) ||
                algid.equals((Object)SHA256_oid) ||
                algid.equals((Object)SHA384_oid) ||
                algid.equals((Object)SHA512_oid) ||
                algid.equals((Object)DSA_oid) ||
                algid.equals((Object)sha1WithDSA_oid)) {
                ; // no parameter part encoded
            } else {
                bytes.putNull();
            }*/
            bytes.putNull();
        } else {
            bytes.putDerValue(params);
        }
        tmp.write(DerValue.tag_Sequence, bytes);
        out.write(tmp.toByteArray());
    }


    Returns the DER-encoded X.509 AlgorithmId as a byte array.
/**
     * Returns the DER-encoded X.509 AlgorithmId as a byte array.
     */
    public final byte[] encode() throws IOException {
        DerOutputStream out = new DerOutputStream();
        derEncode(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.
/**
     * 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 <code>getName</code>
     * 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 may be 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 names like "OID.1.2.3.4", when
no particular name for the algorithm is known.
/**
     * Returns a name for the algorithm which may be 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 names like "OID.1.2.3.4", when
     * no particular name for the algorithm is known.
     */
    public String getName() {
        String algName = nameTable.get(algid);
        if (algName != null) {
            return algName;
        }
        if ((params != null) && algid.equals((Object)specifiedWithECDSA_oid)) {
            try {
                AlgorithmId paramsId =
                        AlgorithmId.parse(new DerValue(getEncodedParams()));
                String paramsName = paramsId.getName();
                if (paramsName.equals("SHA")) {
                    paramsName = "SHA1";
                }
                algName = paramsName + "withECDSA";
            } catch (IOException e) {
                // ignore
            }
        }
        return (algName == null) ? algid.toString() : algName;
    }

    public AlgorithmParameters getParameters() {
        return algParams;
    }

    Returns the DER encoded parameter, which can then be
used to initialize java.security.AlgorithmParamters.
Returns: DER encoded parameters, or null not present./**
     * Returns the DER encoded parameter, which can then be
     * used to initialize java.security.AlgorithmParamters.
     *
     * @return DER encoded parameters, or null not present.
     */
    public byte[] getEncodedParams() throws IOException {
        return (params == null) ? null : params.toByteArray();
    }

    Returns true iff the argument indicates the same algorithm
with the same parameters.
/**
     * Returns true iff the argument indicates the same algorithm
     * with the same parameters.
     */
    public boolean equals(AlgorithmId other) {
        boolean paramsEqual =
          (params == null ? other.params == null : params.equals(other.params));
        return (algid.equals((Object)other.algid) && paramsEqual);
    }

    Compares this AlgorithmID to another.  If algorithm parameters are
available, they are compared.  Otherwise, just the object IDs
for the algorithm are compared.
Params: other – preferably an AlgorithmId, else an ObjectIdentifier/**
     * 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
     */
    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.
/**
     * 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);
    }

    Returns a hashcode for this AlgorithmId.
Returns: a hashcode for this AlgorithmId./**
     * Returns a hashcode for this AlgorithmId.
     *
     * @return a hashcode for this AlgorithmId.
     */
    public int hashCode() {
        StringBuilder sbuf = new StringBuilder();
        sbuf.append(algid.toString());
        sbuf.append(paramsToString());
        return sbuf.toString().hashCode();
    }

    Provides a human-readable description of the algorithm parameters.
This may be redefined by subclasses which parse those parameters.
/**
     * Provides a human-readable description of the algorithm parameters.
     * This may be redefined by subclasses which parse those parameters.
     */
    protected String paramsToString() {
        if (params == null) {
            return "";
        } else if (algParams != null) {
            return algParams.toString();
        } else {
            return ", params unparsed";
        }
    }

    Returns a string describing the algorithm and its parameters.
/**
     * Returns a string describing the algorithm and its parameters.
     */
    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.
Params: val – the input value, which contains the algid and, if
         there are any parameters, those parameters.
Throws: IOException – on error.
Returns: 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./**
     * 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.
Params: algname – the name being used
Throws: NoSuchAlgorithmException – on error.
Deprecated: use the short get form of this method./**
     * 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.
Params: algname – the name being used
Throws: NoSuchAlgorithmException – on error./**
     * 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.
Params: algparams – the associated algorithm parameters.
Throws: NoSuchAlgorithmException – on error./**
     * Returns one of the algorithm IDs most commonly associated
     * with this algorithm parameters.
     *
     * @param algparams the associated algorithm parameters.
     * @exception NoSuchAlgorithmException on error.
     */
    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 {
        // See if algname is in printable OID ("dot-dot") notation
        if (name.indexOf('.') != -1) {
            if (name.startsWith("OID.")) {
                return new ObjectIdentifier(name.substring("OID.".length()));
            } else {
                return new ObjectIdentifier(name);
            }
        }

        // Digesting algorithms
        if (name.equalsIgnoreCase("MD5")) {
            return AlgorithmId.MD5_oid;
        }
        if (name.equalsIgnoreCase("MD2")) {
            return AlgorithmId.MD2_oid;
        }
        if (name.equalsIgnoreCase("SHA") || name.equalsIgnoreCase("SHA1")
            || name.equalsIgnoreCase("SHA-1")) {
            return AlgorithmId.SHA_oid;
        }
        if (name.equalsIgnoreCase("SHA-256") ||
            name.equalsIgnoreCase("SHA256")) {
            return AlgorithmId.SHA256_oid;
        }
        if (name.equalsIgnoreCase("SHA-384") ||
            name.equalsIgnoreCase("SHA384")) {
            return AlgorithmId.SHA384_oid;
        }
        if (name.equalsIgnoreCase("SHA-512") ||
            name.equalsIgnoreCase("SHA512")) {
            return AlgorithmId.SHA512_oid;
        }
        if (name.equalsIgnoreCase("SHA-224") ||
            name.equalsIgnoreCase("SHA224")) {
            return AlgorithmId.SHA224_oid;
        }

        // Various public key algorithms
        if (name.equalsIgnoreCase("RSA")) {
            return AlgorithmId.RSAEncryption_oid;
        }
        if (name.equalsIgnoreCase("Diffie-Hellman")
            || name.equalsIgnoreCase("DH")) {
            return AlgorithmId.DH_oid;
        }
        if (name.equalsIgnoreCase("DSA")) {
            return AlgorithmId.DSA_oid;
        }
        if (name.equalsIgnoreCase("EC")) {
            return EC_oid;
        }
        if (name.equalsIgnoreCase("ECDH")) {
            return AlgorithmId.ECDH_oid;
        }

        // Common signature types
        if (name.equalsIgnoreCase("MD5withRSA")
            || name.equalsIgnoreCase("MD5/RSA")) {
            return AlgorithmId.md5WithRSAEncryption_oid;
        }
        if (name.equalsIgnoreCase("MD2withRSA")
            || name.equalsIgnoreCase("MD2/RSA")) {
            return AlgorithmId.md2WithRSAEncryption_oid;
        }
        if (name.equalsIgnoreCase("SHAwithDSA")
            || name.equalsIgnoreCase("SHA1withDSA")
            || name.equalsIgnoreCase("SHA/DSA")
            || name.equalsIgnoreCase("SHA1/DSA")
            || name.equalsIgnoreCase("DSAWithSHA1")
            || name.equalsIgnoreCase("DSS")
            || name.equalsIgnoreCase("SHA-1/DSA")) {
            return AlgorithmId.sha1WithDSA_oid;
        }
        if (name.equalsIgnoreCase("SHA224WithDSA")) {
            return AlgorithmId.sha224WithDSA_oid;
        }
        if (name.equalsIgnoreCase("SHA256WithDSA")) {
            return AlgorithmId.sha256WithDSA_oid;
        }
        if (name.equalsIgnoreCase("SHA1WithRSA")
            || name.equalsIgnoreCase("SHA1/RSA")) {
            return AlgorithmId.sha1WithRSAEncryption_oid;
        }
        if (name.equalsIgnoreCase("SHA1withECDSA")
                || name.equalsIgnoreCase("ECDSA")) {
            return AlgorithmId.sha1WithECDSA_oid;
        }
        if (name.equalsIgnoreCase("SHA224withECDSA")) {
            return AlgorithmId.sha224WithECDSA_oid;
        }
        if (name.equalsIgnoreCase("SHA256withECDSA")) {
            return AlgorithmId.sha256WithECDSA_oid;
        }
        if (name.equalsIgnoreCase("SHA384withECDSA")) {
            return AlgorithmId.sha384WithECDSA_oid;
        }
        if (name.equalsIgnoreCase("SHA512withECDSA")) {
            return AlgorithmId.sha512WithECDSA_oid;
        }

        // See if any of the installed providers supply a mapping from
        // the given algorithm name to an OID string
        String oidString;
        if (!initOidTable) {
            Provider[] provs = Security.getProviders();
            for (int i=0; i<provs.length; i++) {
                for (Enumeration<Object> enum_ = provs[i].keys();
                     enum_.hasMoreElements(); ) {
                    String alias = (String)enum_.nextElement();
                    String upperCaseAlias = alias.toUpperCase(Locale.ENGLISH);
                    int index;
                    if (upperCaseAlias.startsWith("ALG.ALIAS") &&
                            (index=upperCaseAlias.indexOf("OID.", 0)) != -1) {
                        index += "OID.".length();
                        if (index == alias.length()) {
                            // invalid alias entry
                            break;
                        }
                        if (oidTable == null) {
                            oidTable = new HashMap<String,ObjectIdentifier>();
                        }
                        oidString = alias.substring(index);
                        String stdAlgName = provs[i].getProperty(alias);
                        if (stdAlgName != null) {
                            stdAlgName = stdAlgName.toUpperCase(Locale.ENGLISH);
                        }
                        if (stdAlgName != null &&
                                oidTable.get(stdAlgName) == null) {
                            oidTable.put(stdAlgName,
                                         new ObjectIdentifier(oidString));
                        }
                    }
                }
            }

            if (oidTable == null) {
                oidTable = Collections.<String,ObjectIdentifier>emptyMap();
            }
            initOidTable = true;
        }

        return oidTable.get(name.toUpperCase(Locale.ENGLISH));
    }

    private static ObjectIdentifier oid(int ... values) {
        return ObjectIdentifier.newInternal(values);
    }

    private static boolean initOidTable = false;
    private static Map<String,ObjectIdentifier> oidTable;
    private static final Map<ObjectIdentifier,String> nameTable;

    /*****************************************************************/

    /*
     * HASHING ALGORITHMS
     */

    Algorithm ID for the MD2 Message Digest Algorthm, from RFC 1319.
OID = 1.2.840.113549.2.2
/**
     * Algorithm ID for the MD2 Message Digest Algorthm, from RFC 1319.
     * OID = 1.2.840.113549.2.2
     */
    public static final ObjectIdentifier MD2_oid =
    ObjectIdentifier.newInternal(new int[] {1, 2, 840, 113549, 2, 2});

    Algorithm ID for the MD5 Message Digest Algorthm, from RFC 1321.
OID = 1.2.840.113549.2.5
/**
     * Algorithm ID for the MD5 Message Digest Algorthm, from RFC 1321.
     * OID = 1.2.840.113549.2.5
     */
    public static final ObjectIdentifier MD5_oid =
    ObjectIdentifier.newInternal(new int[] {1, 2, 840, 113549, 2, 5});

    Algorithm ID for the SHA1 Message Digest Algorithm, from FIPS 180-1.
This is sometimes called "SHA", though that is often confusing since
many people refer to FIPS 180 (which has an error) as defining SHA.
OID = 1.3.14.3.2.26. Old SHA-0 OID: 1.3.14.3.2.18.
/**
     * Algorithm ID for the SHA1 Message Digest Algorithm, from FIPS 180-1.
     * This is sometimes called "SHA", though that is often confusing since
     * many people refer to FIPS 180 (which has an error) as defining SHA.
     * OID = 1.3.14.3.2.26. Old SHA-0 OID: 1.3.14.3.2.18.
     */
    public static final ObjectIdentifier SHA_oid =
    ObjectIdentifier.newInternal(new int[] {1, 3, 14, 3, 2, 26});

    public static final ObjectIdentifier SHA224_oid =
    ObjectIdentifier.newInternal(new int[] {2, 16, 840, 1, 101, 3, 4, 2, 4});

    public static final ObjectIdentifier SHA256_oid =
    ObjectIdentifier.newInternal(new int[] {2, 16, 840, 1, 101, 3, 4, 2, 1});

    public static final ObjectIdentifier SHA384_oid =
    ObjectIdentifier.newInternal(new int[] {2, 16, 840, 1, 101, 3, 4, 2, 2});

    public static final ObjectIdentifier SHA512_oid =
    ObjectIdentifier.newInternal(new int[] {2, 16, 840, 1, 101, 3, 4, 2, 3});

    /*
     * COMMON PUBLIC KEY TYPES
     */
    private static final int DH_data[] = { 1, 2, 840, 113549, 1, 3, 1 };
    private static final int DH_PKIX_data[] = { 1, 2, 840, 10046, 2, 1 };
    private static final int DSA_OIW_data[] = { 1, 3, 14, 3, 2, 12 };
    private static final int DSA_PKIX_data[] = { 1, 2, 840, 10040, 4, 1 };
    private static final int RSA_data[] = { 1, 2, 5, 8, 1, 1 };
    private static final int RSAEncryption_data[] =
                                 { 1, 2, 840, 113549, 1, 1, 1 };

    public static final ObjectIdentifier DH_oid;
    public static final ObjectIdentifier DH_PKIX_oid;
    public static final ObjectIdentifier DSA_oid;
    public static final ObjectIdentifier DSA_OIW_oid;
    public static final ObjectIdentifier EC_oid = oid(1, 2, 840, 10045, 2, 1);
    public static final ObjectIdentifier ECDH_oid = oid(1, 3, 132, 1, 12);
    public static final ObjectIdentifier RSA_oid;
    public static final ObjectIdentifier RSAEncryption_oid;

    /*
     * COMMON SIGNATURE ALGORITHMS
     */
    private static final int md2WithRSAEncryption_data[] =
                                       { 1, 2, 840, 113549, 1, 1, 2 };
    private static final int md5WithRSAEncryption_data[] =
                                       { 1, 2, 840, 113549, 1, 1, 4 };
    private static final int sha1WithRSAEncryption_data[] =
                                       { 1, 2, 840, 113549, 1, 1, 5 };
    private static final int sha1WithRSAEncryption_OIW_data[] =
                                       { 1, 3, 14, 3, 2, 29 };
    private static final int sha224WithRSAEncryption_data[] =
                                       { 1, 2, 840, 113549, 1, 1, 14 };
    private static final int sha256WithRSAEncryption_data[] =
                                       { 1, 2, 840, 113549, 1, 1, 11 };
    private static final int sha384WithRSAEncryption_data[] =
                                       { 1, 2, 840, 113549, 1, 1, 12 };
    private static final int sha512WithRSAEncryption_data[] =
                                       { 1, 2, 840, 113549, 1, 1, 13 };
    private static final int shaWithDSA_OIW_data[] =
                                       { 1, 3, 14, 3, 2, 13 };
    private static final int sha1WithDSA_OIW_data[] =
                                       { 1, 3, 14, 3, 2, 27 };
    private static final int dsaWithSHA1_PKIX_data[] =
                                       { 1, 2, 840, 10040, 4, 3 };

    public static final ObjectIdentifier md2WithRSAEncryption_oid;
    public static final ObjectIdentifier md5WithRSAEncryption_oid;
    public static final ObjectIdentifier sha1WithRSAEncryption_oid;
    public static final ObjectIdentifier sha1WithRSAEncryption_OIW_oid;
    public static final ObjectIdentifier sha224WithRSAEncryption_oid;
    public static final ObjectIdentifier sha256WithRSAEncryption_oid;
    public static final ObjectIdentifier sha384WithRSAEncryption_oid;
    public static final ObjectIdentifier sha512WithRSAEncryption_oid;
    public static final ObjectIdentifier shaWithDSA_OIW_oid;
    public static final ObjectIdentifier sha1WithDSA_OIW_oid;
    public static final ObjectIdentifier sha1WithDSA_oid;
    public static final ObjectIdentifier sha224WithDSA_oid =
                                            oid(2, 16, 840, 1, 101, 3, 4, 3, 1);
    public static final ObjectIdentifier sha256WithDSA_oid =
                                            oid(2, 16, 840, 1, 101, 3, 4, 3, 2);

    public static final ObjectIdentifier sha1WithECDSA_oid =
                                            oid(1, 2, 840, 10045, 4, 1);
    public static final ObjectIdentifier sha224WithECDSA_oid =
                                            oid(1, 2, 840, 10045, 4, 3, 1);
    public static final ObjectIdentifier sha256WithECDSA_oid =
                                            oid(1, 2, 840, 10045, 4, 3, 2);
    public static final ObjectIdentifier sha384WithECDSA_oid =
                                            oid(1, 2, 840, 10045, 4, 3, 3);
    public static final ObjectIdentifier sha512WithECDSA_oid =
                                            oid(1, 2, 840, 10045, 4, 3, 4);
    public static final ObjectIdentifier specifiedWithECDSA_oid =
                                            oid(1, 2, 840, 10045, 4, 3);

    Algorithm ID for the PBE encryption algorithms from PKCS#5 and
PKCS#12.
/**
     * Algorithm ID for the PBE encryption algorithms from PKCS#5 and
     * PKCS#12.
     */
    public static final ObjectIdentifier pbeWithMD5AndDES_oid =
        ObjectIdentifier.newInternal(new int[]{1, 2, 840, 113549, 1, 5, 3});
    public static final ObjectIdentifier pbeWithMD5AndRC2_oid =
        ObjectIdentifier.newInternal(new int[] {1, 2, 840, 113549, 1, 5, 6});
    public static final ObjectIdentifier pbeWithSHA1AndDES_oid =
        ObjectIdentifier.newInternal(new int[] {1, 2, 840, 113549, 1, 5, 10});
    public static final ObjectIdentifier pbeWithSHA1AndRC2_oid =
        ObjectIdentifier.newInternal(new int[] {1, 2, 840, 113549, 1, 5, 11});
    public static ObjectIdentifier pbeWithSHA1AndDESede_oid =
        ObjectIdentifier.newInternal(new int[] {1, 2, 840, 113549, 1, 12, 1, 3});
    public static ObjectIdentifier pbeWithSHA1AndRC2_40_oid =
        ObjectIdentifier.newInternal(new int[] {1, 2, 840, 113549, 1, 12, 1, 6});

    static {
    /*
     * Note the preferred OIDs are named simply with no "OIW" or
     * "PKIX" in them, even though they may point to data from these
     * specs; e.g. SHA_oid, DH_oid, DSA_oid, SHA1WithDSA_oid...
     */
    /**
     * Algorithm ID for Diffie Hellman Key agreement, from PKCS #3.
     * Parameters include public values P and G, and may optionally specify
     * the length of the private key X.  Alternatively, algorithm parameters
     * may be derived from another source such as a Certificate Authority's
     * certificate.
     * OID = 1.2.840.113549.1.3.1
     */
        DH_oid = ObjectIdentifier.newInternal(DH_data);

    /**
     * Algorithm ID for the Diffie Hellman Key Agreement (DH), from RFC 3279.
     * Parameters may include public values P and G.
     * OID = 1.2.840.10046.2.1
     */
        DH_PKIX_oid = ObjectIdentifier.newInternal(DH_PKIX_data);

    /**
     * Algorithm ID for the Digital Signing Algorithm (DSA), from the
     * NIST OIW Stable Agreements part 12.
     * Parameters may include public values P, Q, and G; or these may be
     * derived from
     * another source such as a Certificate Authority's certificate.
     * OID = 1.3.14.3.2.12
     */
        DSA_OIW_oid = ObjectIdentifier.newInternal(DSA_OIW_data);

    /**
     * Algorithm ID for the Digital Signing Algorithm (DSA), from RFC 3279.
     * Parameters may include public values P, Q, and G; or these may be
     * derived from another source such as a Certificate Authority's
     * certificate.
     * OID = 1.2.840.10040.4.1
     */
        DSA_oid = ObjectIdentifier.newInternal(DSA_PKIX_data);

    /**
     * Algorithm ID for RSA keys used for any purpose, as defined in X.509.
     * The algorithm parameter is a single value, the number of bits in the
     * public modulus.
     * OID = 1.2.5.8.1.1
     */
        RSA_oid = ObjectIdentifier.newInternal(RSA_data);

    /**
     * Algorithm ID for RSA keys used with RSA encryption, as defined
     * in PKCS #1.  There are no parameters associated with this algorithm.
     * OID = 1.2.840.113549.1.1.1
     */
        RSAEncryption_oid = ObjectIdentifier.newInternal(RSAEncryption_data);

    /**
     * Identifies a signing algorithm where an MD2 digest is encrypted
     * using an RSA private key; defined in PKCS #1.  Use of this
     * signing algorithm is discouraged due to MD2 vulnerabilities.
     * OID = 1.2.840.113549.1.1.2
     */
        md2WithRSAEncryption_oid =
            ObjectIdentifier.newInternal(md2WithRSAEncryption_data);

    /**
     * Identifies a signing algorithm where an MD5 digest is
     * encrypted using an RSA private key; defined in PKCS #1.
     * OID = 1.2.840.113549.1.1.4
     */
        md5WithRSAEncryption_oid =
            ObjectIdentifier.newInternal(md5WithRSAEncryption_data);

    /**
     * Identifies a signing algorithm where a SHA1 digest is
     * encrypted using an RSA private key; defined by RSA DSI.
     * OID = 1.2.840.113549.1.1.5
     */
        sha1WithRSAEncryption_oid =
            ObjectIdentifier.newInternal(sha1WithRSAEncryption_data);

    /**
     * Identifies a signing algorithm where a SHA1 digest is
     * encrypted using an RSA private key; defined in NIST OIW.
     * OID = 1.3.14.3.2.29
     */
        sha1WithRSAEncryption_OIW_oid =
            ObjectIdentifier.newInternal(sha1WithRSAEncryption_OIW_data);

    /**
     * Identifies a signing algorithm where a SHA224 digest is
     * encrypted using an RSA private key; defined by PKCS #1.
     * OID = 1.2.840.113549.1.1.14
     */
        sha224WithRSAEncryption_oid =
            ObjectIdentifier.newInternal(sha224WithRSAEncryption_data);

    /**
     * Identifies a signing algorithm where a SHA256 digest is
     * encrypted using an RSA private key; defined by PKCS #1.
     * OID = 1.2.840.113549.1.1.11
     */
        sha256WithRSAEncryption_oid =
            ObjectIdentifier.newInternal(sha256WithRSAEncryption_data);

    /**
     * Identifies a signing algorithm where a SHA384 digest is
     * encrypted using an RSA private key; defined by PKCS #1.
     * OID = 1.2.840.113549.1.1.12
     */
        sha384WithRSAEncryption_oid =
            ObjectIdentifier.newInternal(sha384WithRSAEncryption_data);

    /**
     * Identifies a signing algorithm where a SHA512 digest is
     * encrypted using an RSA private key; defined by PKCS #1.
     * OID = 1.2.840.113549.1.1.13
     */
        sha512WithRSAEncryption_oid =
            ObjectIdentifier.newInternal(sha512WithRSAEncryption_data);

    /**
     * Identifies the FIPS 186 "Digital Signature Standard" (DSS), where a
     * SHA digest is signed using the Digital Signing Algorithm (DSA).
     * This should not be used.
     * OID = 1.3.14.3.2.13
     */
        shaWithDSA_OIW_oid = ObjectIdentifier.newInternal(shaWithDSA_OIW_data);

    /**
     * Identifies the FIPS 186 "Digital Signature Standard" (DSS), where a
     * SHA1 digest is signed using the Digital Signing Algorithm (DSA).
     * OID = 1.3.14.3.2.27
     */
        sha1WithDSA_OIW_oid = ObjectIdentifier.newInternal(sha1WithDSA_OIW_data);

    /**
     * Identifies the FIPS 186 "Digital Signature Standard" (DSS), where a
     * SHA1 digest is signed using the Digital Signing Algorithm (DSA).
     * OID = 1.2.840.10040.4.3
     */
        sha1WithDSA_oid = ObjectIdentifier.newInternal(dsaWithSHA1_PKIX_data);

        nameTable = new HashMap<ObjectIdentifier,String>();
        nameTable.put(MD5_oid, "MD5");
        nameTable.put(MD2_oid, "MD2");
        nameTable.put(SHA_oid, "SHA");
        nameTable.put(SHA224_oid, "SHA224");
        nameTable.put(SHA256_oid, "SHA256");
        nameTable.put(SHA384_oid, "SHA384");
        nameTable.put(SHA512_oid, "SHA512");
        nameTable.put(RSAEncryption_oid, "RSA");
        nameTable.put(RSA_oid, "RSA");
        nameTable.put(DH_oid, "Diffie-Hellman");
        nameTable.put(DH_PKIX_oid, "Diffie-Hellman");
        nameTable.put(DSA_oid, "DSA");
        nameTable.put(DSA_OIW_oid, "DSA");
        nameTable.put(EC_oid, "EC");
        nameTable.put(ECDH_oid, "ECDH");

        nameTable.put(sha1WithECDSA_oid, "SHA1withECDSA");
        nameTable.put(sha224WithECDSA_oid, "SHA224withECDSA");
        nameTable.put(sha256WithECDSA_oid, "SHA256withECDSA");
        nameTable.put(sha384WithECDSA_oid, "SHA384withECDSA");
        nameTable.put(sha512WithECDSA_oid, "SHA512withECDSA");
        nameTable.put(md5WithRSAEncryption_oid, "MD5withRSA");
        nameTable.put(md2WithRSAEncryption_oid, "MD2withRSA");
        nameTable.put(sha1WithDSA_oid, "SHA1withDSA");
        nameTable.put(sha1WithDSA_OIW_oid, "SHA1withDSA");
        nameTable.put(shaWithDSA_OIW_oid, "SHA1withDSA");
        nameTable.put(sha224WithDSA_oid, "SHA224withDSA");
        nameTable.put(sha256WithDSA_oid, "SHA256withDSA");
        nameTable.put(sha1WithRSAEncryption_oid, "SHA1withRSA");
        nameTable.put(sha1WithRSAEncryption_OIW_oid, "SHA1withRSA");
        nameTable.put(sha224WithRSAEncryption_oid, "SHA224withRSA");
        nameTable.put(sha256WithRSAEncryption_oid, "SHA256withRSA");
        nameTable.put(sha384WithRSAEncryption_oid, "SHA384withRSA");
        nameTable.put(sha512WithRSAEncryption_oid, "SHA512withRSA");
        nameTable.put(pbeWithMD5AndDES_oid, "PBEWithMD5AndDES");
        nameTable.put(pbeWithMD5AndRC2_oid, "PBEWithMD5AndRC2");
        nameTable.put(pbeWithSHA1AndDES_oid, "PBEWithSHA1AndDES");
        nameTable.put(pbeWithSHA1AndRC2_oid, "PBEWithSHA1AndRC2");
        nameTable.put(pbeWithSHA1AndDESede_oid, "PBEWithSHA1AndDESede");
        nameTable.put(pbeWithSHA1AndRC2_40_oid, "PBEWithSHA1AndRC2_40");
    }

    Creates a signature algorithm name from a digest algorithm
name and a encryption algorithm name.
/**
     * Creates a signature algorithm name from a digest algorithm
     * name and a encryption algorithm name.
     */
    public static String makeSigAlg(String digAlg, String encAlg) {
        digAlg = digAlg.replace("-", "").toUpperCase(Locale.ENGLISH);
        if (digAlg.equalsIgnoreCase("SHA")) digAlg = "SHA1";

        encAlg = encAlg.toUpperCase(Locale.ENGLISH);
        if (encAlg.equals("EC")) encAlg = "ECDSA";

        return digAlg + "with" + encAlg;
    }

    Extracts the encryption algorithm name from a signature
algorithm name.
/**
     * Extracts the encryption algorithm name from a signature
     * algorithm name.
      */
    public static String getEncAlgFromSigAlg(String signatureAlgorithm) {
        signatureAlgorithm = signatureAlgorithm.toUpperCase(Locale.ENGLISH);
        int with = signatureAlgorithm.indexOf("WITH");
        String keyAlgorithm = null;
        if (with > 0) {
            int and = signatureAlgorithm.indexOf("AND", with + 4);
            if (and > 0) {
                keyAlgorithm = signatureAlgorithm.substring(with + 4, and);
            } else {
                keyAlgorithm = signatureAlgorithm.substring(with + 4);
            }
            if (keyAlgorithm.equalsIgnoreCase("ECDSA")) {
                keyAlgorithm = "EC";
            }
        }
        return keyAlgorithm;
    }

    Extracts the digest algorithm name from a signature
algorithm name.
/**
     * Extracts the digest algorithm name from a signature
     * algorithm name.
      */
    public static String getDigAlgFromSigAlg(String signatureAlgorithm) {
        signatureAlgorithm = signatureAlgorithm.toUpperCase(Locale.ENGLISH);
        int with = signatureAlgorithm.indexOf("WITH");
        if (with > 0) {
            return signatureAlgorithm.substring(0, with);
        }
        return null;
    }

    // Copied from com.sun.crypto.provider.OAEPParameters.convertToStandardName()
    public static String getStandardDigestName(String internalName) {
        if (internalName.equals("SHA")) {
            return "SHA-1";
        } else if (internalName.equals("SHA224")) {
            return "SHA-224";
        } else if (internalName.equals("SHA256")) {
            return "SHA-256";
        } else if (internalName.equals("SHA384")) {
            return "SHA-384";
        } else if (internalName.equals("SHA512")) {
            return "SHA-512";
        } else {
            return internalName;
        }
    }
}
Params:	out – the output stream on which to write the DER encoding.
Throws:	IOException – on encoding error.
Params:	val – the input value, which contains the algid and, if there are any parameters, those parameters.
Throws:	IOException – on error.
Returns:	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.
Params:	algname – the name being used
Throws:	NoSuchAlgorithmException – on error.
Deprecated:	use the short get form of this method.
Params:	algparams – the associated algorithm parameters.
Throws:	NoSuchAlgorithmException – on error.
/

java/ 6/ sun/security/x509/AlgorithmId.java
