Java tutorial
/* * Copyright (C) 2016 Nikita Mikhailov <nikita.s.mikhailov@gmail.com> * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package org.sufficientlysecure.keychain.securitytoken; import org.bouncycastle.asn1.ASN1ObjectIdentifier; import org.bouncycastle.util.Arrays; import org.bouncycastle.util.encoders.Hex; import org.sufficientlysecure.keychain.pgp.CanonicalizedSecretKey; import org.sufficientlysecure.keychain.pgp.exception.PgpGeneralException; import org.sufficientlysecure.keychain.securitytoken.ECKeyFormat; import org.sufficientlysecure.keychain.securitytoken.RSAKeyFormat; import org.sufficientlysecure.keychain.securitytoken.KeyType; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.math.BigInteger; import java.security.interfaces.ECPrivateKey; import java.security.interfaces.ECPublicKey; import java.security.interfaces.RSAPrivateCrtKey; public class SecurityTokenUtils { public static byte[] attributesFromSecretKey(final KeyType slot, final CanonicalizedSecretKey secretKey) throws IOException, PgpGeneralException { if (secretKey.isRSA()) { final int mModulusLength = secretKey.getBitStrength(); final int mExponentLength = secretKey.getSecurityTokenRSASecretKey().getPublicExponent().bitLength(); final byte[] attrs = new byte[6]; int i = 0; attrs[i++] = (byte) 0x01; attrs[i++] = (byte) ((mModulusLength >> 8) & 0xff); attrs[i++] = (byte) (mModulusLength & 0xff); attrs[i++] = (byte) ((mExponentLength >> 8) & 0xff); attrs[i++] = (byte) (mExponentLength & 0xff); attrs[i++] = RSAKeyFormat.RSAAlgorithmFormat.CRT_WITH_MODULUS.getValue(); return attrs; } else if (secretKey.isEC()) { final byte[] oid = new ASN1ObjectIdentifier(secretKey.getCurveOid()).getEncoded(); final byte[] attrs = new byte[1 + (oid.length - 2) + 1]; if (slot.equals(KeyType.SIGN)) attrs[0] = ECKeyFormat.ECAlgorithmFormat.ECDSA_WITH_PUBKEY.getValue(); else { attrs[0] = ECKeyFormat.ECAlgorithmFormat.ECDH_WITH_PUBKEY.getValue(); } System.arraycopy(oid, 2, attrs, 1, (oid.length - 2)); attrs[attrs.length - 1] = (byte) 0xff; return attrs; } else { throw new IOException("Unsupported key type"); } } public static byte[] createRSAPrivKeyTemplate(RSAPrivateCrtKey secretKey, KeyType slot, RSAKeyFormat format) throws IOException { ByteArrayOutputStream stream = new ByteArrayOutputStream(), template = new ByteArrayOutputStream(), data = new ByteArrayOutputStream(), res = new ByteArrayOutputStream(); int expLengthBytes = (format.getExponentLength() + 7) / 8; // Public exponent template.write(new byte[] { (byte) 0x91, (byte) expLengthBytes }); writeBits(data, secretKey.getPublicExponent(), expLengthBytes); // Prime P, length 128 template.write(Hex.decode("928180")); writeBits(data, secretKey.getPrimeP(), 128); // Prime Q, length 128 template.write(Hex.decode("938180")); writeBits(data, secretKey.getPrimeQ(), 128); if (format.getAlgorithmFormat().isIncludeCrt()) { // Coefficient (1/q mod p), length 128 template.write(Hex.decode("948180")); writeBits(data, secretKey.getCrtCoefficient(), 128); // Prime exponent P (d mod (p - 1)), length 128 template.write(Hex.decode("958180")); writeBits(data, secretKey.getPrimeExponentP(), 128); // Prime exponent Q (d mod (1 - 1)), length 128 template.write(Hex.decode("968180")); writeBits(data, secretKey.getPrimeExponentQ(), 128); } if (format.getAlgorithmFormat().isIncludeModulus()) { // Modulus, length 256, last item in private key template template.write(Hex.decode("97820100")); writeBits(data, secretKey.getModulus(), 256); } // Bundle up // Ext header list data // Control Reference Template to indicate the private key stream.write(slot.getSlot()); stream.write(0); // Cardholder private key template stream.write(Hex.decode("7F48")); stream.write(encodeLength(template.size())); stream.write(template.toByteArray()); // Concatenation of key data as defined in DO 7F48 stream.write(Hex.decode("5F48")); stream.write(encodeLength(data.size())); stream.write(data.toByteArray()); // Result tlv res.write(Hex.decode("4D")); res.write(encodeLength(stream.size())); res.write(stream.toByteArray()); return res.toByteArray(); } public static byte[] createECPrivKeyTemplate(ECPrivateKey secretKey, ECPublicKey publicKey, KeyType slot, ECKeyFormat format) throws IOException { ByteArrayOutputStream stream = new ByteArrayOutputStream(), template = new ByteArrayOutputStream(), data = new ByteArrayOutputStream(), res = new ByteArrayOutputStream(); final int csize = (int) Math.ceil(publicKey.getParams().getCurve().getField().getFieldSize() / 8.0); writeBits(data, secretKey.getS(), csize); template.write(Hex.decode("92")); template.write(encodeLength(data.size())); if (format.getAlgorithmFormat().isWithPubkey()) { data.write(Hex.decode("04")); writeBits(data, publicKey.getW().getAffineX(), csize); writeBits(data, publicKey.getW().getAffineY(), csize); template.write(Hex.decode("99")); template.write(encodeLength(1 + 2 * csize)); } // Bundle up // Ext header list data // Control Reference Template to indicate the private key stream.write(slot.getSlot()); stream.write(0); // Cardholder private key template stream.write(Hex.decode("7F48")); stream.write(encodeLength(template.size())); stream.write(template.toByteArray()); // Concatenation of key data as defined in DO 7F48 stream.write(Hex.decode("5F48")); stream.write(encodeLength(data.size())); stream.write(data.toByteArray()); // Result tlv res.write(Hex.decode("4D")); res.write(encodeLength(stream.size())); res.write(stream.toByteArray()); return res.toByteArray(); } public static byte[] encodeLength(int len) { if (len < 0) { throw new IllegalArgumentException("length is negative"); } else if (len >= 16777216) { throw new IllegalArgumentException("length is too big: " + len); } byte[] res; if (len < 128) { res = new byte[1]; res[0] = (byte) len; } else if (len < 256) { res = new byte[2]; res[0] = -127; res[1] = (byte) len; } else if (len < 65536) { res = new byte[3]; res[0] = -126; res[1] = (byte) (len / 256); res[2] = (byte) (len % 256); } else { res = new byte[4]; res[0] = -125; res[1] = (byte) (len / 65536); res[2] = (byte) (len / 256); res[3] = (byte) (len % 256); } return res; } public static void writeBits(ByteArrayOutputStream stream, BigInteger value, int width) { if (value.signum() == -1) { throw new IllegalArgumentException("value is negative"); } else if (width <= 0) { throw new IllegalArgumentException("width <= 0"); } final byte[] prime = value.toByteArray(); int skip = 0; while ((skip < prime.length) && (prime[skip] == 0)) ++skip; if ((prime.length - skip) > width) { throw new IllegalArgumentException( "not enough width to fit value: " + (prime.length - skip) + "/" + width); } byte[] res = new byte[width]; System.arraycopy(prime, skip, res, width - (prime.length - skip), prime.length - skip); stream.write(res, 0, width); Arrays.fill(res, (byte) 0); Arrays.fill(prime, (byte) 0); } }