Decrypting PEM file using Triple DES

Question

Hi all,
I am trying to decrypt a Triple DES encrypted RSAPrivateKey stored in PEM format in a file. How do I get the DES key to initialize the Cipher. I am using the following code to get the IV from the file and get the DES key using pass phrase. But I get the message
java.lang.SecurityException: Unsupported keysize or algorithm parameters
Can someone help me.
Thanks in advance,
Trilok.
// Gets the IV params from the RSAPrivate key PEM file.
// Uses the last 16 digits in this line to get the IV.
// DEK-Info: DES-EDE3-CBC,4A90C209D3A81791
private IvParameterSpec getIV(String s) { // here s = 4A90C209D3A81791
byte[] ivBytes = new byte[8];
for (int j=0; j<8; j++) {
ivBytes[j] = (byte)Integer.parseInt(s.substring(j*2, j*2 + 2), 16);
return new IvParameterSpec(ivBytes);
private SecretKeySpec getSecretKey(byte [] pwd, byte [] iv)
throws NoSuchAlgorithmException {
     byte[] keyMat = new byte[24];
     MessageDigest md = MessageDigest.getInstance("MD5");
     md.update(pwd);
     md.update(iv);
     byte[] data = md.digest();
     System.arraycopy(data, 0, keyMat, 0, 16);
     md.update(data);
     md.update(pwd);
     md.update(iv);
     data = md.digest();
     System.arraycopy(data, 0, keyMat, 16, 8);
     return new SecretKeySpec(keyMat, encAlg);
}

Answer 1

Hi trilok,
Please let me know what JCE provider you are using for decrypting the Key.
Please make sure that you have made the static or dynamic registration properly.
For Static registration:
Please go to JAVA_HOME/jre/lib/security/java.security
Please edit
security.provider.1=sun.security.provider.Sun
For Dynamic Registration
Security.addProvider(new com.sun.crypto.provider.SunJCE());
Also please refer this URL, which is the third party provider which supports RSA.
http://www.bouncycastle.org/latest_releases.html
I hope this will help you.
Thanks
Bakrudeen
Technical Support Engineer
Sun MicroSystems Inc, India