netconf/callhome-protocol/src/main/java/org/opendaylight/netconf/callhome/protocol/AuthorizedKeysDecoder.java

   1 /*
   2  * Copyright (c) 2016 Brocade Communication Systems and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.netconf.callhome.protocol;
   9
  10 import java.io.ByteArrayOutputStream;
  11 import java.io.DataOutputStream;
  12 import java.io.IOException;
  13 import java.math.BigInteger;
  14 import java.security.GeneralSecurityException;
  15 import java.security.KeyFactory;
  16 import java.security.PublicKey;
  17 import java.security.interfaces.DSAParams;
  18 import java.security.interfaces.DSAPublicKey;
  19 import java.security.interfaces.RSAPublicKey;
  20 import java.security.spec.DSAPublicKeySpec;
  21 import java.security.spec.ECPoint;
  22 import java.security.spec.ECPublicKeySpec;
  23 import java.security.spec.RSAPublicKeySpec;
  24 import java.util.Arrays;
  25 import java.util.Base64;
  26 import java.util.HashMap;
  27 import java.util.Map;
  28 import org.apache.sshd.common.util.security.SecurityUtils;
  29 import org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPublicKey;
  30 import org.bouncycastle.jce.ECNamedCurveTable;
  31 import org.bouncycastle.jce.ECPointUtil;
  32 import org.bouncycastle.jce.spec.ECNamedCurveParameterSpec;
  33 import org.bouncycastle.jce.spec.ECNamedCurveSpec;
  34
  35 /**
  36  * FIXME: This should be probably located at AAA library.
  37  */
  38 public class AuthorizedKeysDecoder {
  39
  40     private static final String KEY_FACTORY_TYPE_RSA = "RSA";
  41     private static final String KEY_FACTORY_TYPE_DSA = "DSA";
  42     private static final String KEY_FACTORY_TYPE_ECDSA = "EC";
  43
  44     private static final Map<String, String> ECDSA_CURVES = new HashMap<>();
  45
  46     static {
  47         ECDSA_CURVES.put("nistp256", "secp256r1");
  48         ECDSA_CURVES.put("nistp384", "secp384r1");
  49         ECDSA_CURVES.put("nistp512", "secp512r1");
  50     }
  51
  52     private static final String ECDSA_SUPPORTED_CURVE_NAME = "nistp256";
  53     private static final String ECDSA_SUPPORTED_CURVE_NAME_SPEC = ECDSA_CURVES.get(ECDSA_SUPPORTED_CURVE_NAME);
  54
  55     private static final String KEY_TYPE_RSA = "ssh-rsa";
  56     private static final String KEY_TYPE_DSA = "ssh-dss";
  57     private static final String KEY_TYPE_ECDSA = "ecdsa-sha2-" + ECDSA_SUPPORTED_CURVE_NAME;
  58
  59     private byte[] bytes = new byte[0];
  60     private int pos = 0;
  61
  62     public PublicKey decodePublicKey(final String keyLine) throws GeneralSecurityException {
  63
  64         // look for the Base64 encoded part of the line to decode
  65         // both ssh-rsa and ssh-dss begin with "AAAA" due to the length bytes
  66         bytes = Base64.getDecoder().decode(keyLine.getBytes());
  67         if (bytes.length == 0) {
  68             throw new IllegalArgumentException("No Base64 part to decode in " + keyLine);
  69         }
  70
  71         pos = 0;
  72
  73         String type = decodeType();
  74         if (type.equals(KEY_TYPE_RSA)) {
  75             return decodeAsRSA();
  76         }
  77
  78         if (type.equals(KEY_TYPE_DSA)) {
  79             return decodeAsDSA();
  80         }
  81
  82         if (type.equals(KEY_TYPE_ECDSA)) {
  83             return decodeAsEcDSA();
  84         }
  85
  86         throw new IllegalArgumentException("Unknown decode key type " + type + " in " + keyLine);
  87     }
  88
  89     private PublicKey decodeAsEcDSA() throws GeneralSecurityException {
  90         KeyFactory ecdsaFactory = SecurityUtils.getKeyFactory(KEY_FACTORY_TYPE_ECDSA);
  91
  92         ECNamedCurveParameterSpec spec256r1 = ECNamedCurveTable.getParameterSpec(ECDSA_SUPPORTED_CURVE_NAME_SPEC);
  93         ECNamedCurveSpec params256r1 = new ECNamedCurveSpec(
  94             ECDSA_SUPPORTED_CURVE_NAME_SPEC, spec256r1.getCurve(), spec256r1.getG(), spec256r1.getN());
  95         // copy last 65 bytes from ssh key.
  96         ECPoint point = ECPointUtil.decodePoint(params256r1.getCurve(), Arrays.copyOfRange(bytes, 39, bytes.length));
  97         ECPublicKeySpec pubKeySpec = new ECPublicKeySpec(point, params256r1);
  98
  99         return ecdsaFactory.generatePublic(pubKeySpec);
 100     }
 101
 102     private PublicKey decodeAsDSA() throws GeneralSecurityException {
 103         KeyFactory dsaFactory = SecurityUtils.getKeyFactory(KEY_FACTORY_TYPE_DSA);
 104         BigInteger prime = decodeBigInt();
 105         BigInteger subPrime = decodeBigInt();
 106         BigInteger base = decodeBigInt();
 107         BigInteger publicKey = decodeBigInt();
 108         DSAPublicKeySpec spec = new DSAPublicKeySpec(publicKey, prime, subPrime, base);
 109
 110         return dsaFactory.generatePublic(spec);
 111     }
 112
 113     private PublicKey decodeAsRSA() throws GeneralSecurityException {
 114         KeyFactory rsaFactory = SecurityUtils.getKeyFactory(KEY_FACTORY_TYPE_RSA);
 115         BigInteger exponent = decodeBigInt();
 116         BigInteger modulus = decodeBigInt();
 117         RSAPublicKeySpec spec = new RSAPublicKeySpec(modulus, exponent);
 118
 119         return rsaFactory.generatePublic(spec);
 120     }
 121
 122     private String decodeType() {
 123         int len = decodeInt();
 124         String type = new String(bytes, pos, len);
 125         pos += len;
 126         return type;
 127     }
 128
 129     private int decodeInt() {
 130         return (bytes[pos++] & 0xFF) << 24 | (bytes[pos++] & 0xFF) << 16
 131                 | (bytes[pos++] & 0xFF) << 8 | bytes[pos++] & 0xFF;
 132     }
 133
 134     private BigInteger decodeBigInt() {
 135         int len = decodeInt();
 136         byte[] bigIntBytes = new byte[len];
 137         System.arraycopy(bytes, pos, bigIntBytes, 0, len);
 138         pos += len;
 139         return new BigInteger(bigIntBytes);
 140     }
 141
 142     public static String encodePublicKey(final PublicKey publicKey) throws IOException {
 143         String publicKeyEncoded;
 144         ByteArrayOutputStream byteOs = new ByteArrayOutputStream();
 145         if (publicKey.getAlgorithm().equals(KEY_FACTORY_TYPE_RSA)) {
 146             RSAPublicKey rsaPublicKey = (RSAPublicKey) publicKey;
 147             DataOutputStream dout = new DataOutputStream(byteOs);
 148             dout.writeInt(KEY_TYPE_RSA.getBytes().length);
 149             dout.write(KEY_TYPE_RSA.getBytes());
 150             dout.writeInt(rsaPublicKey.getPublicExponent().toByteArray().length);
 151             dout.write(rsaPublicKey.getPublicExponent().toByteArray());
 152             dout.writeInt(rsaPublicKey.getModulus().toByteArray().length);
 153             dout.write(rsaPublicKey.getModulus().toByteArray());
 154         } else if (publicKey.getAlgorithm().equals(KEY_FACTORY_TYPE_DSA)) {
 155             DSAPublicKey dsaPublicKey = (DSAPublicKey) publicKey;
 156             DSAParams dsaParams = dsaPublicKey.getParams();
 157             DataOutputStream dout = new DataOutputStream(byteOs);
 158             dout.writeInt(KEY_TYPE_DSA.getBytes().length);
 159             dout.write(KEY_TYPE_DSA.getBytes());
 160             dout.writeInt(dsaParams.getP().toByteArray().length);
 161             dout.write(dsaParams.getP().toByteArray());
 162             dout.writeInt(dsaParams.getQ().toByteArray().length);
 163             dout.write(dsaParams.getQ().toByteArray());
 164             dout.writeInt(dsaParams.getG().toByteArray().length);
 165             dout.write(dsaParams.getG().toByteArray());
 166             dout.writeInt(dsaPublicKey.getY().toByteArray().length);
 167             dout.write(dsaPublicKey.getY().toByteArray());
 168         } else if (publicKey.getAlgorithm().equals(KEY_FACTORY_TYPE_ECDSA)) {
 169             BCECPublicKey ecPublicKey = (BCECPublicKey) publicKey;
 170             DataOutputStream dout = new DataOutputStream(byteOs);
 171             dout.writeInt(KEY_TYPE_ECDSA.getBytes().length);
 172             dout.write(KEY_TYPE_ECDSA.getBytes());
 173             dout.writeInt(ECDSA_SUPPORTED_CURVE_NAME.getBytes().length);
 174             dout.write(ECDSA_SUPPORTED_CURVE_NAME.getBytes());
 175
 176             byte[] coordX = ecPublicKey.getQ().getAffineXCoord().getEncoded();
 177             byte[] coordY = ecPublicKey.getQ().getAffineYCoord().getEncoded();
 178             dout.writeInt(coordX.length + coordY.length + 1);
 179             dout.writeByte(0x04);
 180             dout.write(coordX);
 181             dout.write(coordY);
 182         } else {
 183             throw new IllegalArgumentException("Unknown public key encoding: " + publicKey.getAlgorithm());
 184         }
 185         publicKeyEncoded = new String(Base64.getEncoder().encodeToString(byteOs.toByteArray()));
 186         return publicKeyEncoded;
 187     }
 188 }