apps/callhome-provider/src/main/java/org/opendaylight/netconf/callhome/mount/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.mount;
   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 /**
  39  * FIXME: This should be probably located at AAA library.
  40  */
  41 public class AuthorizedKeysDecoder {
  42     private static final Logger LOG = LoggerFactory.getLogger(AuthorizedKeysDecoder.class);
  43
  44     private static final ImmutableMap<String, String> ECDSA_CURVES = ImmutableMap.<String, String>builder()
  45         .put("nistp256", "secp256r1")
  46         .put("nistp384", "secp384r1")
  47         .put("nistp512", "secp512r1")
  48         .build();
  49
  50     private static final String ECDSA_SUPPORTED_CURVE_NAME = "nistp256";
  51     private static final byte[] ECDSA_SUPPORTED_CURVE_NAME_BYTES =
  52         ECDSA_SUPPORTED_CURVE_NAME.getBytes(StandardCharsets.UTF_8);
  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 byte[] KEY_TYPE_RSA_BYTES = KEY_TYPE_RSA.getBytes(StandardCharsets.UTF_8);
  57
  58     private static final String KEY_TYPE_DSA = "ssh-dss";
  59     private static final byte[] KEY_TYPE_DSA_BYTES = KEY_TYPE_DSA.getBytes(StandardCharsets.UTF_8);
  60     private static final String KEY_TYPE_ECDSA = "ecdsa-sha2-" + ECDSA_SUPPORTED_CURVE_NAME;
  61     private static final byte[] KEY_TYPE_ECDSA_BYTES = KEY_TYPE_ECDSA.getBytes(StandardCharsets.UTF_8);
  62
  63     private static final KeyFactory RSA_FACTORY = loadOrWarn("RSA");
  64     private static final KeyFactory DSA_FACTORY = loadOrWarn("DSA");
  65     private static final KeyFactory EC_FACTORY = loadOrWarn("EC");
  66
  67     private static KeyFactory loadOrWarn(final String algorithm) {
  68         try {
  69             return KeyFactory.getInstance(algorithm);
  70         } catch (NoSuchAlgorithmException e) {
  71             LOG.warn("KeyFactory for {} not found", algorithm, e);
  72             return null;
  73         }
  74     }
  75
  76     private byte[] bytes = new byte[0];
  77     private int pos = 0;
  78
  79     public PublicKey decodePublicKey(final SshPublicKey keyLine) throws GeneralSecurityException {
  80         bytes = keyLine.getValue();
  81         pos = 0;
  82
  83         final var type = decodeType();
  84         return switch (type) {
  85             case KEY_TYPE_RSA -> decodeAsRSA();
  86             case KEY_TYPE_DSA -> decodeAsDSA();
  87             case KEY_TYPE_ECDSA -> decodeAsEcDSA();
  88             default -> throw new IllegalArgumentException("Unknown decode key type " + type + " in " + keyLine);
  89         };
  90     }
  91
  92     private PublicKey decodeAsEcDSA() throws GeneralSecurityException {
  93         if (EC_FACTORY == null) {
  94             throw new NoSuchAlgorithmException("ECDSA keys are not supported");
  95         }
  96
  97         ECNamedCurveParameterSpec spec256r1 = ECNamedCurveTable.getParameterSpec(ECDSA_SUPPORTED_CURVE_NAME_SPEC);
  98         ECNamedCurveSpec params256r1 = new ECNamedCurveSpec(
  99             ECDSA_SUPPORTED_CURVE_NAME_SPEC, spec256r1.getCurve(), spec256r1.getG(), spec256r1.getN());
 100         // copy last 65 bytes from ssh key.
 101         ECPoint point = ECPointUtil.decodePoint(params256r1.getCurve(), Arrays.copyOfRange(bytes, 39, bytes.length));
 102         return EC_FACTORY.generatePublic(new ECPublicKeySpec(point, params256r1));
 103     }
 104
 105     private PublicKey decodeAsDSA() throws GeneralSecurityException {
 106         if (DSA_FACTORY == null) {
 107             throw new NoSuchAlgorithmException("RSA keys are not supported");
 108         }
 109
 110         final var p = decodeBigInt();
 111         final var q = decodeBigInt();
 112         final var g = decodeBigInt();
 113         final var y = decodeBigInt();
 114         return DSA_FACTORY.generatePublic(new DSAPublicKeySpec(y, p, q, g));
 115     }
 116
 117     private PublicKey decodeAsRSA() throws GeneralSecurityException {
 118         if (RSA_FACTORY == null) {
 119             throw new NoSuchAlgorithmException("RSA keys are not supported");
 120         }
 121
 122         final var exponent = decodeBigInt();
 123         final var modulus = decodeBigInt();
 124         return RSA_FACTORY.generatePublic(new RSAPublicKeySpec(modulus, exponent));
 125     }
 126
 127     private String decodeType() {
 128         int len = decodeInt();
 129         String type = new String(bytes, pos, len, StandardCharsets.UTF_8);
 130         pos += len;
 131         return type;
 132     }
 133
 134     private int decodeInt() {
 135         return (bytes[pos++] & 0xFF) << 24 | (bytes[pos++] & 0xFF) << 16
 136                 | (bytes[pos++] & 0xFF) << 8 | bytes[pos++] & 0xFF;
 137     }
 138
 139     private BigInteger decodeBigInt() {
 140         int len = decodeInt();
 141         byte[] bigIntBytes = new byte[len];
 142         System.arraycopy(bytes, pos, bigIntBytes, 0, len);
 143         pos += len;
 144         return new BigInteger(bigIntBytes);
 145     }
 146
 147     private static void encodeBigInt(final DataOutput out, final BigInteger value) throws IOException {
 148         final var bytes = value.toByteArray();
 149         out.writeInt(bytes.length);
 150         out.write(bytes);
 151     }
 152
 153     public static @NonNull SshPublicKey encodePublicKey(final PublicKey publicKey) throws IOException {
 154         final var baos = new ByteArrayOutputStream();
 155
 156         try (var dout = new DataOutputStream(baos)) {
 157             if (publicKey instanceof RSAPublicKey rsa) {
 158                 dout.writeInt(KEY_TYPE_RSA_BYTES.length);
 159                 dout.write(KEY_TYPE_RSA_BYTES);
 160                 encodeBigInt(dout, rsa.getPublicExponent());
 161                 encodeBigInt(dout, rsa.getModulus());
 162             } else if (publicKey instanceof DSAPublicKey dsa) {
 163                 final var dsaParams = dsa.getParams();
 164                 dout.writeInt(KEY_TYPE_DSA_BYTES.length);
 165                 dout.write(KEY_TYPE_DSA_BYTES);
 166                 encodeBigInt(dout, dsaParams.getP());
 167                 encodeBigInt(dout, dsaParams.getQ());
 168                 encodeBigInt(dout, dsaParams.getG());
 169                 encodeBigInt(dout, dsa.getY());
 170             } else if (publicKey instanceof ECPublicKey ec) {
 171                 dout.writeInt(KEY_TYPE_ECDSA_BYTES.length);
 172                 dout.write(KEY_TYPE_ECDSA_BYTES);
 173                 dout.writeInt(ECDSA_SUPPORTED_CURVE_NAME_BYTES.length);
 174                 dout.write(ECDSA_SUPPORTED_CURVE_NAME_BYTES);
 175
 176                 final var q = ec.getQ();
 177                 final var coordX = q.getAffineXCoord().getEncoded();
 178                 final var coordY = q.getAffineYCoord().getEncoded();
 179                 dout.writeInt(coordX.length + coordY.length + 1);
 180                 dout.writeByte(0x04);
 181                 dout.write(coordX);
 182                 dout.write(coordY);
 183             } else {
 184                 throw new IOException("Unknown public key encoding: " + publicKey);
 185             }
 186         }
 187         return new SshPublicKey(baos.toByteArray());
 188     }
 189 }