1 files changed, 66 insertions, 0 deletions
diff --git a/libraries/spongycastle/prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/rsa/RSAUtil.java b/libraries/spongycastle/prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/rsa/RSAUtil.java
new file mode 100644
index 000000000..da57ec3b6
--- /dev/null
+++ b/libraries/spongycastle/prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/rsa/RSAUtil.java
@@ -0,0 +1,66 @@
+package org.spongycastle.jcajce.provider.asymmetric.rsa;
+
+import java.security.interfaces.RSAPrivateCrtKey;
+import java.security.interfaces.RSAPrivateKey;
+import java.security.interfaces.RSAPublicKey;
+
+import org.spongycastle.asn1.ASN1ObjectIdentifier;
+import org.spongycastle.asn1.pkcs.PKCSObjectIdentifiers;
+import org.spongycastle.asn1.x509.X509ObjectIdentifiers;
+import org.spongycastle.crypto.params.RSAKeyParameters;
+import org.spongycastle.crypto.params.RSAPrivateCrtKeyParameters;
+
+/**
+ * utility class for converting java.security RSA objects into their
+ * org.spongycastle.crypto counterparts.
+ */
+public class RSAUtil
+{
+    public static final ASN1ObjectIdentifier[] rsaOids =
+    {
+        PKCSObjectIdentifiers.rsaEncryption,
+        X509ObjectIdentifiers.id_ea_rsa,
+        PKCSObjectIdentifiers.id_RSAES_OAEP,
+        PKCSObjectIdentifiers.id_RSASSA_PSS
+    };
+
+    public static boolean isRsaOid(
+        ASN1ObjectIdentifier algOid)
+    {
+        for (int i = 0; i != rsaOids.length; i++)
+        {
+            if (algOid.equals(rsaOids[i]))
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    static RSAKeyParameters generatePublicKeyParameter(
+        RSAPublicKey key)
+    {
+        return new RSAKeyParameters(false, key.getModulus(), key.getPublicExponent());
+
+    }
+
+    static RSAKeyParameters generatePrivateKeyParameter(
+        RSAPrivateKey key)
+    {
+        if (key instanceof RSAPrivateCrtKey)
+        {
+            RSAPrivateCrtKey k = (RSAPrivateCrtKey)key;
+
+            return new RSAPrivateCrtKeyParameters(k.getModulus(),
+                k.getPublicExponent(), k.getPrivateExponent(),
+                k.getPrimeP(), k.getPrimeQ(), k.getPrimeExponentP(), k.getPrimeExponentQ(), k.getCrtCoefficient());
+        }
+        else
+        {
+            RSAPrivateKey k = key;
+
+            return new RSAKeyParameters(true, k.getModulus(), k.getPrivateExponent());
+        }
+    }
+}