LsUq7wEj

1public static void main(final String[] args)
2{
3  final BitsProvider bitsProvider = Random256BitsProvider.INSTANCE;
4
5  System.out.format("Example #%02d%n", i);
6  final byte[] identityUnlockKey = bitsProvider.get();
7  dumpInHex("Identity Unlock Key", identityUnlockKey);
8  final IdentityLock identityLock = new IdentityLock(identityUnlockKey);
9
10  final byte[] randomLockVal = bitsProvider.get();
11  dumpInHex("Random Lock Val", randomLockVal);
12  final IdentityLockForSite identityLockForSite = identityLock.getLockForSite(randomLockVal);
13}
14
15
16final class IdentityLock
17{
18  private final byte[] identityLockKey;
19  private final byte[] identityUnlockKey;
20  
21  public IdentityLock(final byte[] identityUnlockKey)
22  {
23    this.identityUnlockKey = identityUnlockKey.clone();
24    identityLockKey = makePublic(identityUnlockKey);
25    dumpInHex("Identity Lock Key", identityLockKey);
26  }
27
28  public IdentityLockForSite getLockForSite(final byte[] siteLockVal)
29  {
30    final byte[] serverUnlockKey = makePublic(siteLockVal);
31    dumpInHex("Server Unlock Key", serverUnlockKey);
32
33    final byte[] keyAgreementVal1 = dhka(identityLockKey, siteLockVal);
34    dumpInHex("DH Key Agreement Val 1", keyAgreementVal1);
35
36    final byte[] verifyUnlockKey = getPublicKeyForSeed(keyAgreementVal1);
37    dumpInHex("Verify Unlock Key", verifyUnlockKey);
38    
39    // Now make sure it works
40    System.out.println();
41    System.out.println("Steps and values for verifying identity unlock:");
42    final byte[] keyAgreementVal2 = dhka(serverUnlockKey, identityUnlockKey);
43    dumpInHex("DH Key Agreement Val 2", keyAgreementVal2);
44
45    final byte[] unlockRequestSigningKey = getPrivateKeyForSeed(keyAgreementVal2);
46    dumpInHex("Unlock Request Signing Key", unlockRequestSigningKey);
47  }
48}
49
50
51byte[] getPublicKeyForSeed(final byte[] seedForKeyPair)
52{
53  final byte[] privateKeyBytes = new byte[SECRETKEYBYTES];
54  final byte[] publicKeyBytes  = new byte[PUBLICKEYBYTES];
55  crypto_sign_seed_keypair(publicKeyBytes, privateKeyBytes, seedForKeyPair);
56  return publicKeyBytes;
57}
58
59
60byte[] getPrivateKeyForSeed(final byte[] seedForKeyPair)
61{
62  final byte[] privateKeyBytes = new byte[SECRETKEYBYTES];
63  final byte[] publicKeyBytes  = new byte[PUBLICKEYBYTES];
64  crypto_sign_seed_keypair(publicKeyBytes, privateKeyBytes, seedForKeyPair);
65  return Arrays.copyOfRange(privateKeyBytes, 32, 64);
66}
67
68
69public static byte[] makePublic(final byte[] secretKey)
70{
71  byte[] result = new byte[PUBLICKEYBYTES];
72  crypto_scalarmult_base(result, secretKey);
73  return result;
74}
75
76
77public static byte[] dhka(final byte[] publicKey, final byte[] secretKey)
78{
79  byte[] result = new byte[SCALARMULT_BYTES];
80  if (crypto_scalarmult(result, secretKey, publicKey) == 0)
81  {
82    return result;
83  }
84  throw new IllegalStateException("crypto_scalarmult failed");
85}