I am trying to generate ECDSA key pair using SpongyCastle in Android. This is the code:
static {
Security.insertProviderAt(new org.spongycastle.jce.provider.BouncyCastleProvider(), 1);
}
public static KeyPair generate() {
ECParameterSpec ecSpec = ECNamedCurveTable.getParameterSpec("prime256v1");
KeyPairGenerator generator = KeyPairGenerator.getInstance("ECDSA", "SC");
generator.initialize(ecSpec, new SecureRandom());
KeyPair keyPair = g.generateKeyPair();
Log.i(TAG, "EC Pub Key generated: " + utils.bytesToHex(keyPair.getPublic().getEncoded()));
Log.i(TAG, "EC Private Key generated: " + utils.bytesToHex(keyPair.getPrivate().getEncoded()));
return generator.generateKeyPair();
}
Something is wrong since I always get something like that example of Public Key:
3059301306072A8648CE3D020106082A8648CE3D03010703420004483ABA9F322240010ECF00E818C041A60FE71A2BD64C64CD5A60519985F110AEDE6308027D2730303F5E2478F083C7F5BB683DCAC22BFEB62F3A48BD01009F40
and Private Key:
308193020100301306072A8648CE3D020106082A8648CE3D030107047930770201010420219AB4B3701630973A4B2917D53F69A4BE6DAD61F48016BFEF147B2999575CB2A00A06082A8648CE3D030107A14403420004483ABA9F322240010ECF00E818C041A60FE71A2BD64C64CD5A60519985F110AEDE6308027D2730303F5E2478F083C7F5BB683DCAC22BFEB62F3A48BD01009F40
The site ECDSA sample give me "Invalid ECDSA signature message", and them seems really very different from that smaller Private Key and always starting with "04" Public Key generated in the same site.
Also, my backend verification gives me the error "Invalid point encoding 0x30"
The backend Java method check is:
public ECPublicKey getPublicKeyFromHex(String publicKeyHex)
throws NoSuchAlgorithmException, DecoderException, ApplicationGenericException {
byte[] rawPublicKey = Hex.decodeHex(publicKeyHex.toCharArray());
ECPublicKey ecPublicKey = null;
KeyFactory kf = null;
ECNamedCurveParameterSpec ecNamedCurveParameterSpec = ECNamedCurveTable.getParameterSpec("prime256v1");
ECCurve curve = ecNamedCurveParameterSpec.getCurve();
EllipticCurve ellipticCurve = EC5Util.convertCurve(curve, ecNamedCurveParameterSpec.getSeed());
java.security.spec.ECPoint ecPoint = ECPointUtil.decodePoint(ellipticCurve, rawPublicKey);
java.security.spec.ECParameterSpec ecParameterSpec = EC5Util.convertSpec(ellipticCurve,
ecNamedCurveParameterSpec);
java.security.spec.ECPublicKeySpec publicKeySpec = new java.security.spec.ECPublicKeySpec(ecPoint,
ecParameterSpec);
kf = KeyFactory.getInstance("ECDSA", new BouncyCastleProvider());
try {
ecPublicKey = (ECPublicKey) kf.generatePublic(publicKeySpec);
} catch (Exception e) {
throw new ApplicationGenericException(e.getMessage(), e.getCause());
}
return ecPublicKey;
}