How to store PublicKey and PrivateKey in database??

[Jahnvi Vyas]

Hello,

I am developing web application using JSP and MySql 5.1. I want to store PublicKey as well PrivateKey in my database.

The data type which I use to store key is BLOB. But I dont know how to store or retrive this. I tried with byte[]. By doing this I am able to store and retrive key, but it is as byte[] datatype. I want to retrive this as PublicKey or PrivateKey and there are no ways to convert byte[] to and Key type.

So, where am I goin wrong?? Are there any other ways to store and retrive Key??? And which datatype I should use for field??

Thanks.

Jahnvi..

[Aryan Khan]

You can use normal varchar field and encode the keys in lets say base64 and store it and while retreiving decode.

Ahmad

[Jahnvi Vyas]

Thanks Ahmad.

My actual problem is not how to store a key but to retrive it. Let me tell you exactly what I am trying to do:

1. I am generating PublicKey and PrivateKey from KeyPairGenerator and fetching them with getPublicKey() and getPrivateKey(). Then I am storing them in database where my field type is BLOB.

2. Now I want to fetch this key in byte[]. But there are no ways to convert byte[] into PrivateKey and PublicKey. I want them in key form because I want to further sign data with this PrivateKey and to initialize Signature object I must pass argument as PrivateKey (not as byte[]).

I hope now you got the actual problem. If you have further suggestions then I will be very much thankful.

Thanks.

Jahnvi

[greg stark]

Use the getEncoded() method to get the byte[] from the keys. To go the other way, getting an RSAPublicKey or RSAPrivateKey from a byte[], use the appropriate KeyFactory methods and encoded key specs, e.g. for RSAPrivateKey

// byte [] encodedKey contains the RSA private key retrieved from the DB
KeyFactory rsaKeyFac = KeyFactory.getInstance("RSA");
PKCS8EncodedKeySpec encodedKeySpec = new PKCS8EncodedKeySpec(encodedKey);
RSAPrivateKey privKey = (RSAPrivateKey)rsaKeyFac.generatePrivate(encodedKeySpec);

and for RSAPublicKey

KeyFactory rsaKeyFac = KeyFactory.getInstance("RSA");
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(encKey);
RSAPublicKey pubKey = (RSAPublicKey )rsaKeyFac .generatePublic(keySpec);

[Jahnvi Vyas]

Thanks Greg.

I tried that code (RSAPublicKey....) and it works. But now another problem occured. When I am signing message with this key I am getting error:

--> java.security.InvalidKeyException :No Installed provider supports this key:sun.security.rsa.RSAPrivateCrtKeyImpl

So, do I need to install it or simply if I update my jdk version(if it is the cause for the error) will give me proper result?

Thanks..

Jahnvi.

[Aryan Khan]

Download Bouncy Castle provider free from internet.

Ahmad

[Lasse Bergstr�m]

Originally posted by greg stark:
Use the getEncoded() method to get the byte[] from the keys. To go the other way, getting an RSAPublicKey or RSAPrivateKey from a byte[], use the appropriate KeyFactory methods and encoded key specs, e.g. for RSAPrivateKey

// byte [] encodedKey contains the RSA private key retrieved from the DB
KeyFactory rsaKeyFac = KeyFactory.getInstance("RSA");
PKCS8EncodedKeySpec encodedKeySpec = new PKCS8EncodedKeySpec(encodedKey);
RSAPrivateKey privKey = (RSAPrivateKey)rsaKeyFac.generatePrivate(encodedKeySpec);

and for RSAPublicKey

KeyFactory rsaKeyFac = KeyFactory.getInstance("RSA");
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(encKey);
RSAPublicKey pubKey = (RSAPublicKey )rsaKeyFac .generatePublic(keySpec);

Hi,

I applied your code to my example:

rsaKeyFac = KeyFactory.getInstance("RSA");
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(client_privatekey.getEncoded());
RSAPublicKey pubKey = (RSAPublicKey )rsaKeyFac.generatePublic(keySpec);

However I get the following error when executing the last line:
Exception in thread "main" java.security.spec.InvalidKeySpecException: java.security.InvalidKeyException: IOException: algid parse error, not a sequence

Any expeience from this?

Best regards

Lasse