Creating Key Objects from a Set of Digital Signature Algorithm (DSA) Parameters
The DSA requires three parameters to create a key pair – the
prime (P), the subprime (Q), and the base (G). These three values are
used to create a private key (called X) and a public key (called Y).
This example creates a PrivateKey and PublicKey from a set
of DSA parameters.
try {
// Obtain the DSA parameters;
// see Getting the Digital Signature Algorithm (DSA) Parameters of a Key Pair
BigInteger p = ...;
BigInteger q = ...;
BigInteger g = ...;
BigInteger x = ...;
BigInteger y = ...;
// Create the DSA key factory
KeyFactory keyFactory = KeyFactory.getInstance("DSA");
// Create the DSA private key
KeySpec privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
PrivateKey privateKey = keyFactory.generatePrivate(privateKeySpec);
// Create the DSA public key
KeySpec publicKeySpec = new DSAPublicKeySpec(y, p, q, g);
PublicKey publicKey = keyFactory.generatePublic(publicKeySpec);
} catch (InvalidKeySpecException e) {
} catch (NoSuchAlgorithmException e) {
}
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