apps/callhome-provider/src/main/java/org/opendaylight/netconf/topology/callhome/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.topology.callhome;
   9
  10 import com.google.common.collect.ImmutableMap;
  11 import java.io.ByteArrayOutputStream;
  12 import java.io.DataOutput;
  13 import java.io.DataOutputStream;
  14 import java.io.IOException;
  15 import java.math.BigInteger;
  16 import java.nio.charset.StandardCharsets;
  17 import java.security.GeneralSecurityException;
  18 import java.security.KeyFactory;
  19 import java.security.NoSuchAlgorithmException;
  20 import java.security.PublicKey;
  21 import java.security.interfaces.DSAPublicKey;
  22 import java.security.interfaces.RSAPublicKey;
  23 import java.security.spec.DSAPublicKeySpec;
  24 import java.security.spec.ECPoint;
  25 import java.security.spec.ECPublicKeySpec;
  26 import java.security.spec.RSAPublicKeySpec;
  27 import java.util.Arrays;
  28 import org.bouncycastle.jce.ECNamedCurveTable;
  29 import org.bouncycastle.jce.ECPointUtil;
  30 import org.bouncycastle.jce.interfaces.ECPublicKey;
  31 import org.bouncycastle.jce.spec.ECNamedCurveParameterSpec;
  32 import org.bouncycastle.jce.spec.ECNamedCurveSpec;
  33 import org.eclipse.jdt.annotation.NonNull;
  34 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.netconf.callhome.server.rev240129.SshPublicKey;
  35 import org.slf4j.Logger;
  36 import org.slf4j.LoggerFactory;
  37
  38 final class AuthorizedKeysDecoder {
  39     private static final Logger LOG = LoggerFactory.getLogger(AuthorizedKeysDecoder.class);
  40
  41     private static final ImmutableMap<String, String> ECDSA_CURVES = ImmutableMap.<String, String>builder()
  42         .put("nistp256", "secp256r1")
  43         .put("nistp384", "secp384r1")
  44         .put("nistp512", "secp512r1")
  45         .build();
  46
  47     private static final String ECDSA_SUPPORTED_CURVE_NAME = "nistp256";
  48     private static final byte[] ECDSA_SUPPORTED_CURVE_NAME_BYTES =
  49         ECDSA_SUPPORTED_CURVE_NAME.getBytes(StandardCharsets.UTF_8);
  50     private static final String ECDSA_SUPPORTED_CURVE_NAME_SPEC = ECDSA_CURVES.get(ECDSA_SUPPORTED_CURVE_NAME);
  51
  52     private static final String KEY_TYPE_RSA = "ssh-rsa";
  53     private static final byte[] KEY_TYPE_RSA_BYTES = KEY_TYPE_RSA.getBytes(StandardCharsets.UTF_8);
  54
  55     private static final String KEY_TYPE_DSA = "ssh-dss";
  56     private static final byte[] KEY_TYPE_DSA_BYTES = KEY_TYPE_DSA.getBytes(StandardCharsets.UTF_8);
  57     private static final String KEY_TYPE_ECDSA = "ecdsa-sha2-" + ECDSA_SUPPORTED_CURVE_NAME;
  58     private static final byte[] KEY_TYPE_ECDSA_BYTES = KEY_TYPE_ECDSA.getBytes(StandardCharsets.UTF_8);
  59
  60     private static final KeyFactory RSA_FACTORY = loadOrWarn("RSA");
  61     private static final KeyFactory DSA_FACTORY = loadOrWarn("DSA");
  62     private static final KeyFactory EC_FACTORY = loadOrWarn("EC");
  63
  64     private static KeyFactory loadOrWarn(final String algorithm) {
  65         try {
  66             return KeyFactory.getInstance(algorithm);
  67         } catch (NoSuchAlgorithmException e) {
  68             LOG.warn("KeyFactory for {} not found", algorithm, e);
  69             return null;
  70         }
  71     }
  72
  73     private final byte[] bytes;
  74     private int pos;
  75
  76     private AuthorizedKeysDecoder(final SshPublicKey keyLine) {
  77         bytes = keyLine.getValue();
  78     }
  79
  80     static @NonNull PublicKey decodePublicKey(final @NonNull SshPublicKey keyLine) throws GeneralSecurityException {
  81         final var instance = new AuthorizedKeysDecoder(keyLine);
  82         final var type = instance.decodeType();
  83         return switch (type) {
  84             case KEY_TYPE_RSA -> instance.decodeAsRSA();
  85             case KEY_TYPE_DSA -> instance.decodeAsDSA();
  86             case KEY_TYPE_ECDSA -> instance.decodeAsEcDSA();
  87             default -> throw new NoSuchAlgorithmException("Unknown decode key type " + type + " in " + keyLine);
  88         };
  89     }
  90
  91     static @NonNull SshPublicKey encodePublicKey(final PublicKey publicKey) throws IOException {
  92         final var baos = new ByteArrayOutputStream();
  93
  94         try (var dout = new DataOutputStream(baos)) {
  95             if (publicKey instanceof RSAPublicKey rsa) {
  96                 dout.writeInt(KEY_TYPE_RSA_BYTES.length);
  97                 dout.write(KEY_TYPE_RSA_BYTES);
  98                 encodeBigInt(dout, rsa.getPublicExponent());
  99                 encodeBigInt(dout, rsa.getModulus());
 100             } else if (publicKey instanceof DSAPublicKey dsa) {
 101                 final var dsaParams = dsa.getParams();
 102                 dout.writeInt(KEY_TYPE_DSA_BYTES.length);
 103                 dout.write(KEY_TYPE_DSA_BYTES);
 104                 encodeBigInt(dout, dsaParams.getP());
 105                 encodeBigInt(dout, dsaParams.getQ());
 106                 encodeBigInt(dout, dsaParams.getG());
 107                 encodeBigInt(dout, dsa.getY());
 108             } else if (publicKey instanceof ECPublicKey ec) {
 109                 dout.writeInt(KEY_TYPE_ECDSA_BYTES.length);
 110                 dout.write(KEY_TYPE_ECDSA_BYTES);
 111                 dout.writeInt(ECDSA_SUPPORTED_CURVE_NAME_BYTES.length);
 112                 dout.write(ECDSA_SUPPORTED_CURVE_NAME_BYTES);
 113
 114                 final var q = ec.getQ();
 115                 final var coordX = q.getAffineXCoord().getEncoded();
 116                 final var coordY = q.getAffineYCoord().getEncoded();
 117                 dout.writeInt(coordX.length + coordY.length + 1);
 118                 dout.writeByte(0x04);
 119                 dout.write(coordX);
 120                 dout.write(coordY);
 121             } else {
 122                 throw new IOException("Unknown public key encoding: " + publicKey);
 123             }
 124         }
 125         return new SshPublicKey(baos.toByteArray());
 126     }
 127
 128     private @NonNull PublicKey decodeAsEcDSA() throws GeneralSecurityException {
 129         if (EC_FACTORY == null) {
 130             throw new NoSuchAlgorithmException("ECDSA keys are not supported");
 131         }
 132
 133         ECNamedCurveParameterSpec spec256r1 = ECNamedCurveTable.getParameterSpec(ECDSA_SUPPORTED_CURVE_NAME_SPEC);
 134         ECNamedCurveSpec params256r1 = new ECNamedCurveSpec(
 135             ECDSA_SUPPORTED_CURVE_NAME_SPEC, spec256r1.getCurve(), spec256r1.getG(), spec256r1.getN());
 136         // copy last 65 bytes from ssh key.
 137         ECPoint point = ECPointUtil.decodePoint(params256r1.getCurve(), Arrays.copyOfRange(bytes, 39, bytes.length));
 138         return EC_FACTORY.generatePublic(new ECPublicKeySpec(point, params256r1));
 139     }
 140
 141     private @NonNull PublicKey decodeAsDSA() throws GeneralSecurityException {
 142         if (DSA_FACTORY == null) {
 143             throw new NoSuchAlgorithmException("RSA keys are not supported");
 144         }
 145
 146         final var p = decodeBigInt();
 147         final var q = decodeBigInt();
 148         final var g = decodeBigInt();
 149         final var y = decodeBigInt();
 150         return DSA_FACTORY.generatePublic(new DSAPublicKeySpec(y, p, q, g));
 151     }
 152
 153     private @NonNull PublicKey decodeAsRSA() throws GeneralSecurityException {
 154         if (RSA_FACTORY == null) {
 155             throw new NoSuchAlgorithmException("RSA keys are not supported");
 156         }
 157
 158         final var exponent = decodeBigInt();
 159         final var modulus = decodeBigInt();
 160         return RSA_FACTORY.generatePublic(new RSAPublicKeySpec(modulus, exponent));
 161     }
 162
 163     private String decodeType() {
 164         int len = decodeInt();
 165         String type = new String(bytes, pos, len, StandardCharsets.UTF_8);
 166         pos += len;
 167         return type;
 168     }
 169
 170     private int decodeInt() {
 171         return (bytes[pos++] & 0xFF) << 24 | (bytes[pos++] & 0xFF) << 16
 172                 | (bytes[pos++] & 0xFF) << 8 | bytes[pos++] & 0xFF;
 173     }
 174
 175     private BigInteger decodeBigInt() {
 176         int len = decodeInt();
 177         byte[] bigIntBytes = new byte[len];
 178         System.arraycopy(bytes, pos, bigIntBytes, 0, len);
 179         pos += len;
 180         return new BigInteger(bigIntBytes);
 181     }
 182
 183     private static void encodeBigInt(final DataOutput out, final BigInteger value) throws IOException {
 184         final var bytes = value.toByteArray();
 185         out.writeInt(bytes.length);
 186         out.write(bytes);
 187     }
 188 }