1 files changed, 124 insertions, 0 deletions
diff --git a/prov/src/main/java/org/spongycastle/jcajce/util/JcaJceUtils.java b/prov/src/main/java/org/spongycastle/jcajce/util/JcaJceUtils.java
new file mode 100644
index 00000000..b1bf5fec
--- /dev/null
+++ b/prov/src/main/java/org/spongycastle/jcajce/util/JcaJceUtils.java
@@ -0,0 +1,124 @@
+package org.spongycastle.jcajce.util;
+
+import java.io.IOException;
+import java.security.AlgorithmParameters;
+
+import org.spongycastle.asn1.ASN1Encodable;
+import org.spongycastle.asn1.ASN1ObjectIdentifier;
+import org.spongycastle.asn1.ASN1Primitive;
+import org.spongycastle.asn1.cryptopro.CryptoProObjectIdentifiers;
+import org.spongycastle.asn1.nist.NISTObjectIdentifiers;
+import org.spongycastle.asn1.oiw.OIWObjectIdentifiers;
+import org.spongycastle.asn1.pkcs.PKCSObjectIdentifiers;
+import org.spongycastle.asn1.teletrust.TeleTrusTObjectIdentifiers;
+
+/**
+ * General JCA/JCE utility methods.
+ */
+public class JcaJceUtils
+{
+    private JcaJceUtils()
+    {
+
+    }
+
+    /**
+     * Extract an ASN.1 encodable from an AlgorithmParameters object.
+     *
+     * @param params the object to get the encoding used to create the return value.
+     * @return an ASN.1 object representing the primitives making up the params parameter.
+     * @throws IOException if an encoding cannot be extracted.
+     */
+    public static ASN1Encodable extractParameters(AlgorithmParameters params)
+        throws IOException
+    {
+        // we try ASN.1 explicitly first just in case and then role back to the default.
+        ASN1Encodable asn1Params;
+        try
+        {
+            asn1Params = ASN1Primitive.fromByteArray(params.getEncoded("ASN.1"));
+        }
+        catch (Exception ex)
+        {
+            asn1Params = ASN1Primitive.fromByteArray(params.getEncoded());
+        }
+
+        return asn1Params;
+    }
+
+    /**
+     * Load an AlgorithmParameters object with the passed in ASN.1 encodable - if possible.
+     *
+     * @param params the AlgorithmParameters object to be initialised.
+     * @param sParams the ASN.1 encodable to initialise params with.
+     * @throws IOException if the parameters cannot be initialised.
+     */
+    public static void loadParameters(AlgorithmParameters params, ASN1Encodable sParams)
+        throws IOException
+    {
+        // we try ASN.1 explicitly first just in case and then role back to the default.
+        try
+        {
+            params.init(sParams.toASN1Primitive().getEncoded(), "ASN.1");
+        }
+        catch (Exception ex)
+        {
+            params.init(sParams.toASN1Primitive().getEncoded());
+        }
+    }
+
+    /**
+     * Attempt to find a standard JCA name for the digest represented by the past 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 getDigestAlgName(
+        ASN1ObjectIdentifier digestAlgOID)
+    {
+        if (PKCSObjectIdentifiers.md5.equals(digestAlgOID))
+        {
+            return "MD5";
+        }
+        else if (OIWObjectIdentifiers.idSHA1.equals(digestAlgOID))
+        {
+            return "SHA1";
+        }
+        else if (NISTObjectIdentifiers.id_sha224.equals(digestAlgOID))
+        {
+            return "SHA224";
+        }
+        else if (NISTObjectIdentifiers.id_sha256.equals(digestAlgOID))
+        {
+            return "SHA256";
+        }
+        else if (NISTObjectIdentifiers.id_sha384.equals(digestAlgOID))
+        {
+            return "SHA384";
+        }
+        else if (NISTObjectIdentifiers.id_sha512.equals(digestAlgOID))
+        {
+            return "SHA512";
+        }
+        else if (TeleTrusTObjectIdentifiers.ripemd128.equals(digestAlgOID))
+        {
+            return "RIPEMD128";
+        }
+        else if (TeleTrusTObjectIdentifiers.ripemd160.equals(digestAlgOID))
+        {
+            return "RIPEMD160";
+        }
+        else if (TeleTrusTObjectIdentifiers.ripemd256.equals(digestAlgOID))
+        {
+            return "RIPEMD256";
+        }
+        else if (CryptoProObjectIdentifiers.gostR3411.equals(digestAlgOID))
+        {
+            return "GOST3411";
+        }
+        else
+        {
+            return digestAlgOID.getId();
+        }
+    }
+}