Java tutorial
package org.bouncycastle.jcajce.util; import java.util.HashMap; import java.util.Map; import org.bouncycastle.asn1.ASN1ObjectIdentifier; import org.bouncycastle.asn1.cryptopro.CryptoProObjectIdentifiers; import org.bouncycastle.asn1.gm.GMObjectIdentifiers; import org.bouncycastle.asn1.gnu.GNUObjectIdentifiers; import org.bouncycastle.asn1.iso.ISOIECObjectIdentifiers; import org.bouncycastle.asn1.nist.NISTObjectIdentifiers; import org.bouncycastle.asn1.oiw.OIWObjectIdentifiers; import org.bouncycastle.asn1.pkcs.PKCSObjectIdentifiers; import org.bouncycastle.asn1.teletrust.TeleTrusTObjectIdentifiers; public class MessageDigestUtils { private static Map<ASN1ObjectIdentifier, String> digestOidMap = new HashMap<ASN1ObjectIdentifier, String>(); static { digestOidMap.put(PKCSObjectIdentifiers.md2, "MD2"); digestOidMap.put(PKCSObjectIdentifiers.md4, "MD4"); digestOidMap.put(PKCSObjectIdentifiers.md5, "MD5"); digestOidMap.put(OIWObjectIdentifiers.idSHA1, "SHA-1"); digestOidMap.put(NISTObjectIdentifiers.id_sha224, "SHA-224"); digestOidMap.put(NISTObjectIdentifiers.id_sha256, "SHA-256"); digestOidMap.put(NISTObjectIdentifiers.id_sha384, "SHA-384"); digestOidMap.put(NISTObjectIdentifiers.id_sha512, "SHA-512"); digestOidMap.put(TeleTrusTObjectIdentifiers.ripemd128, "RIPEMD-128"); digestOidMap.put(TeleTrusTObjectIdentifiers.ripemd160, "RIPEMD-160"); digestOidMap.put(TeleTrusTObjectIdentifiers.ripemd256, "RIPEMD-128"); digestOidMap.put(ISOIECObjectIdentifiers.ripemd128, "RIPEMD-128"); digestOidMap.put(ISOIECObjectIdentifiers.ripemd160, "RIPEMD-160"); digestOidMap.put(CryptoProObjectIdentifiers.gostR3411, "GOST3411"); digestOidMap.put(GNUObjectIdentifiers.Tiger_192, "Tiger"); digestOidMap.put(ISOIECObjectIdentifiers.whirlpool, "Whirlpool"); digestOidMap.put(NISTObjectIdentifiers.id_sha3_224, "SHA3-224"); digestOidMap.put(NISTObjectIdentifiers.id_sha3_256, "SHA3-256"); digestOidMap.put(NISTObjectIdentifiers.id_sha3_384, "SHA3-384"); digestOidMap.put(NISTObjectIdentifiers.id_sha3_512, "SHA3-512"); digestOidMap.put(GMObjectIdentifiers.sm3, "SM3"); } /** * Attempt to find a standard JCA name for the digest represented by the passed in OID. * * @param digestAlgOID the OID of the digest algorithm of interest. * @return a string representing the standard name - the OID as a string if none available. */ public static String getDigestName(ASN1ObjectIdentifier digestAlgOID) { String name = (String) digestOidMap.get(digestAlgOID); // for pre 1.5 JDK if (name != null) { return name; } return digestAlgOID.getId(); } }