Examples with DSAParams java.security.interfaces.DSAParams used on opensource projects

Example 6 with DSAParams

use of java.security.interfaces.DSAParams in project robovm by robovm.

the class KeyPairGenerator4Test method test_initializeLjava_security_spec_AlgorithmParameterSpecLjava_security_SecureRandom.

/**
     * java.security.KeyPairGenerator#initialize(java.security.spec.AlgorithmParameterSpec,
     *        java.security.SecureRandom)
     */
public void test_initializeLjava_security_spec_AlgorithmParameterSpecLjava_security_SecureRandom() throws Exception {
    // create DSAParams
    KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("DSA");
    keyPairGenerator.initialize(1024);
    DSAPublicKey key = (DSAPublicKey) keyPairGenerator.genKeyPair().getPublic();
    DSAParams params = key.getParams();
    KeyPairGenerator keyPair = KeyPairGenerator.getInstance("DSA");
    keyPair.initialize(new DSAParameterSpec(params.getP(), params.getQ(), params.getG()), new SecureRandom());
}

Example 7 with DSAParams

use of java.security.interfaces.DSAParams in project wycheproof by google.

the class DsaTest method testKeyGeneration.

@SuppressWarnings("InsecureCryptoUsage")
public void testKeyGeneration(int keysize) throws Exception {
    KeyPairGenerator generator = KeyPairGenerator.getInstance("DSA");
    generator.initialize(keysize);
    KeyPair keyPair = generator.generateKeyPair();
    DSAPrivateKey priv = (DSAPrivateKey) keyPair.getPrivate();
    DSAParams params = priv.getParams();
    assertEquals(keysize, params.getP().bitLength());
    // The NIST standard does not fully specify the size of q that
    // must be used for a given key size. Hence there are differences.
    // For example if keysize = 2048, then OpenSSL uses 256 bit q's by default,
    // but the SUN provider uses 224 bits. Both are acceptable sizes.
    // The tests below simply asserts that the size of q does not decrease the
    // overall security of the DSA.
    int qsize = params.getQ().bitLength();
    switch(keysize) {
        case 1024:
            assertTrue("Invalid qsize for 1024 bit key:" + qsize, qsize >= 160);
            break;
        case 2048:
            assertTrue("Invalid qsize for 2048 bit key:" + qsize, qsize >= 224);
            break;
        case 3072:
            assertTrue("Invalid qsize for 3072 bit key:" + qsize, qsize >= 256);
            break;
        default:
            fail("Invalid key size:" + keysize);
    }
    // Check the length of the private key.
    // For example GPG4Browsers or the KJUR library derived from it use
    // q.bitCount() instead of q.bitLength() to determine the size of the private key
    // and hence would generate keys that are much too small.
    assertTrue(priv.getX().bitLength() >= qsize - 32);
}

Example 8 with DSAParams

use of java.security.interfaces.DSAParams in project XobotOS by xamarin.

the class SHA1withDSA_SignatureImpl method checkSignature.

private boolean checkSignature(byte[] sigBytes, int offset, int length) throws SignatureException {
    // names of below BigIntegers are the same as they are defined in DSA standard
    BigInteger r, s, w;
    BigInteger u1, u2, v;
    // parameters and public key
    BigInteger p, q, g, y;
    DSAParams params;
    int n1, n2;
    byte[] bytes;
    byte[] digest;
    // checking up on signature's ASN1
    try {
        byte dummy;
        n1 = sigBytes[offset + 3];
        n2 = sigBytes[offset + n1 + 5];
        if (sigBytes[offset + 0] != 0x30 || sigBytes[offset + 2] != 2 || sigBytes[offset + n1 + 4] != 2 || sigBytes[offset + 1] != (n1 + n2 + 4) || n1 > 21 || n2 > 21 || (length != 0 && (sigBytes[offset + 1] + 2) > length)) {
            throw new SignatureException("signature bytes have invalid encoding");
        }
        // to check length of sigBytes
        dummy = sigBytes[5 + n1 + n2];
    } catch (ArrayIndexOutOfBoundsException e) {
        throw new SignatureException("bad argument: byte[] is too small");
    }
    digest = msgDigest.digest();
    bytes = new byte[n1];
    System.arraycopy(sigBytes, offset + 4, bytes, 0, n1);
    r = new BigInteger(bytes);
    bytes = new byte[n2];
    System.arraycopy(sigBytes, offset + 6 + n1, bytes, 0, n2);
    s = new BigInteger(bytes);
    params = dsaKey.getParams();
    p = params.getP();
    q = params.getQ();
    g = params.getG();
    y = ((DSAPublicKey) dsaKey).getY();
    if (r.signum() != 1 || r.compareTo(q) != -1 || s.signum() != 1 || s.compareTo(q) != -1) {
        return false;
    }
    w = s.modInverse(q);
    u1 = (new BigInteger(1, digest)).multiply(w).mod(q);
    u2 = r.multiply(w).mod(q);
    v = g.modPow(u1, p).multiply(y.modPow(u2, p)).mod(p).mod(q);
    if (v.compareTo(r) != 0) {
        return false;
    }
    return true;
}

Example 9 with DSAParams

use of java.security.interfaces.DSAParams in project XobotOS by xamarin.

the class SHA1withDSA_SignatureImpl method engineSign.

/**
     * Returns signature bytes as byte array containing
     * ASN1 representation for two BigInteger objects
     * which is SEQUENCE of two INTEGERS.
     * Length of sequence varies from less than 46 to 48.
     *
     * Resets object to the state it was in
     * when previous call to either "initSign" method was called.
     *
     * @return
     *    byte array containing signature in ASN1 representation
     * @throws
     *    SignatureException if object's state is not SIGN or
     *                       signature algorithm cannot process data
     */
protected byte[] engineSign() throws SignatureException {
    // names of below BigIntegers are the same as they are defined in DSA standard
    BigInteger r = null;
    BigInteger s = null;
    BigInteger k = null;
    // parameters and private key
    BigInteger p, q, g, x;
    // BigInteger for message digest
    BigInteger digestBI;
    // various byte array being used in computing signature
    byte[] randomBytes;
    byte[] rBytes;
    byte[] sBytes;
    byte[] signature;
    int n, n1, n2;
    DSAParams params;
    if (appRandom == null) {
        appRandom = new SecureRandom();
    }
    params = dsaKey.getParams();
    p = params.getP();
    q = params.getQ();
    g = params.getG();
    x = ((DSAPrivateKey) dsaKey).getX();
    // forming signature according algorithm described in chapter 5 of DSA standard
    digestBI = new BigInteger(1, msgDigest.digest());
    randomBytes = new byte[20];
    for (; ; ) {
        appRandom.nextBytes(randomBytes);
        k = new BigInteger(1, randomBytes);
        if (k.compareTo(q) != -1) {
            continue;
        }
        r = g.modPow(k, p).mod(q);
        if (r.signum() == 0) {
            continue;
        }
        s = k.modInverse(q).multiply(digestBI.add(x.multiply(r)).mod(q)).mod(q);
        if (s.signum() != 0) {
            break;
        }
    }
    // forming signature's ASN1 representation which is SEQUENCE of two INTEGERs
    //
    rBytes = r.toByteArray();
    n1 = rBytes.length;
    if ((rBytes[0] & 0x80) != 0) {
        n1++;
    }
    sBytes = s.toByteArray();
    n2 = sBytes.length;
    if ((sBytes[0] & 0x80) != 0) {
        n2++;
    }
    // 48 is max. possible length of signature
    signature = new byte[6 + n1 + n2];
    // ASN1 SEQUENCE tag
    signature[0] = (byte) 0x30;
    // total length of two INTEGERs
    signature[1] = (byte) (4 + n1 + n2);
    // ASN1 INTEGER tag
    signature[2] = (byte) 0x02;
    // length of r
    signature[3] = (byte) n1;
    // ASN1 INTEGER tag
    signature[4 + n1] = (byte) 0x02;
    // length of s
    signature[5 + n1] = (byte) n2;
    if (n1 == rBytes.length) {
        n = 4;
    } else {
        n = 5;
    }
    System.arraycopy(rBytes, 0, signature, n, rBytes.length);
    if (n2 == sBytes.length) {
        n = 6 + n1;
    } else {
        n = 7 + n1;
    }
    System.arraycopy(sBytes, 0, signature, n, sBytes.length);
    return signature;
}

Example 10 with DSAParams

use of java.security.interfaces.DSAParams in project XobotOS by xamarin.

the class DSAKeyFactoryImpl method engineGetKeySpec.

/**
     * This method returns a specification for the supplied key.
     *
     * The specification will be returned in the form of an object of the type
     * specified by keySpec.
     *
     * @param key -
     *            either DSAPrivateKey or DSAPublicKey
     * @param keySpec -
     *            either DSAPrivateKeySpec.class or DSAPublicKeySpec.class
     *
     * @return either a DSAPrivateKeySpec or a DSAPublicKeySpec
     *
     * @throws InvalidKeySpecException
     *             if "keySpec" is not a specification for DSAPublicKey or
     *             DSAPrivateKey
     */
protected <T extends KeySpec> T engineGetKeySpec(Key key, Class<T> keySpec) throws InvalidKeySpecException {
    BigInteger p, q, g, x, y;
    if (key != null) {
        if (keySpec == null) {
            throw new NullPointerException("keySpec == null");
        }
        if (key instanceof DSAPrivateKey) {
            DSAPrivateKey privateKey = (DSAPrivateKey) key;
            if (keySpec.equals(DSAPrivateKeySpec.class)) {
                x = privateKey.getX();
                DSAParams params = privateKey.getParams();
                p = params.getP();
                q = params.getQ();
                g = params.getG();
                return (T) (new DSAPrivateKeySpec(x, p, q, g));
            }
            if (keySpec.equals(PKCS8EncodedKeySpec.class)) {
                return (T) (new PKCS8EncodedKeySpec(key.getEncoded()));
            }
            throw new InvalidKeySpecException("'keySpec' is neither DSAPrivateKeySpec nor PKCS8EncodedKeySpec");
        }
        if (key instanceof DSAPublicKey) {
            DSAPublicKey publicKey = (DSAPublicKey) key;
            if (keySpec.equals(DSAPublicKeySpec.class)) {
                y = publicKey.getY();
                DSAParams params = publicKey.getParams();
                p = params.getP();
                q = params.getQ();
                g = params.getG();
                return (T) (new DSAPublicKeySpec(y, p, q, g));
            }
            if (keySpec.equals(X509EncodedKeySpec.class)) {
                return (T) (new X509EncodedKeySpec(key.getEncoded()));
            }
            throw new InvalidKeySpecException("'keySpec' is neither DSAPublicKeySpec nor X509EncodedKeySpec");
        }
    }
    throw new InvalidKeySpecException("'key' is neither DSAPublicKey nor DSAPrivateKey");
}