// From email with Scott Fluhrer:
// To generate the SEED for a child LMS tree, we will adapt algorithm A by using the
// I value of the parent LMS tree the q value to be the LMS index of the child, and the i value to be 65534.
// Algorithm A:
// x_q[i] = H(I || u32str(q) || u16str(i) || u8str(0xff) || SEED).
// UPDATE: Generate child I from algorithm A using the I value of the parent LMS tree, the q value
// to be the LMS index of the child, and the i value to be 65535; the I value will be the first 128 bits of the hash.
public Hss(int layers, LmsType[] lmsTypes, LmotsType[] lmotsTypes,
EntropyProviderTypes entropyType = EntropyProviderTypes.Random, BitString seed = null, BitString rootI = null)
{
_entropyType = entropyType;
_entropyProvider = _entropyFactory.GetEntropyProvider(entropyType);
_entropyProvider.AddEntropy(seed);
SEED = _entropyProvider.GetEntropy(256); // for now will only be 256 bits (m = 256)
_entropyProvider.AddEntropy(rootI);
RootI = _entropyProvider.GetEntropy(128);
_sha256 = new NativeFastSha2_256();
_lms = new Lms[layers];
_lmsTypes = lmsTypes;
_lmotsTypes = lmotsTypes;
_lms[0] = new Lms(lmsTypes[0], lmotsTypes[0], entropyType, SEED, rootI);
var parentSeed = SEED;
var parentI = RootI;
for (int i = 1; i < layers; i++)
{
var childSeed = _sha256.HashMessage(parentI
.ConcatenateBits(new BitString(0, 32))
.ConcatenateBits(new BitString(65534, 16))
.ConcatenateBits(new BitString("ff", 8))
.ConcatenateBits(parentSeed)).Digest;
var I = _sha256.HashMessage(parentI
.ConcatenateBits(new BitString(0, 32))
.ConcatenateBits(new BitString(65535, 16))
.ConcatenateBits(new BitString("ff", 8))
.ConcatenateBits(parentSeed)).Digest.MSBSubstring(0, 128);
_lms[i] = new Lms(lmsTypes[i], lmotsTypes[i], entropyType, childSeed, I);
parentSeed = childSeed;
parentI = I;
}
}
public IDsaEcc GetInstance(HashFunction hashFunction, EntropyProviderTypes entropyType = EntropyProviderTypes.Random)
{
// KAS ECC is using the base IDsa function that relies on a hash function and entropy type.
// Kas ECC should be the only method using this function, but I didn't want to mark it obsolete,
// as the FFC KAS also uses this function from the base IDsa interface.
return(new EccDsa(_shaFactory.GetShaInstance(hashFunction), _entropyProviderFactory.GetEntropyProvider(entropyType)));
}
public Lmots(LmotsType type, EntropyProviderTypes entropyType = EntropyProviderTypes.Random)
{
var(n, w, p, ls, siglen, typecode) = LmotsModeMapping.GetValsFromType(type);
_n = n;
_w = w;
_p = p;
_ls = ls;
_siglen = siglen;
_typecode = typecode;
_entropyProvider = _entropyFactory.GetEntropyProvider(entropyType);
_isRandom = entropyType == EntropyProviderTypes.Random;
_sha256 = new NativeFastSha2_256();
}
/// <summary>
/// Returns a new instance of an <see cref="IEntropyProvider"/>
/// </summary>
/// <param name="providerType">The <see cref="IEntropyProvider"/> type </param>
/// <exception cref="ArgumentException">Thrown when <see cref="providerType"/> is invalid</exception>
/// <returns></returns>
public IEntropyProvider GetEntropyProvider(EntropyProviderTypes providerType)
{
switch (providerType)
{
case EntropyProviderTypes.Testable:
return(new TestableEntropyProvider());
case EntropyProviderTypes.Random:
return(new EntropyProvider(new Random800_90()));
default:
throw new ArgumentException($"Invalid {providerType} supplied.");
}
}
private const int H25_PIECE_SIZE = 32768; // creates 1024 threads
#endregion Fields
#region Constructors
// From an email from Scott Fluhrer:
// To generate the I value for the LMS tree, we will adapt algorithm A,
// by setting the I value input to be the all-zeros value, the q value
// to be 0 and the i value to be 65535; we will use the first 16 bytes of the hash output.
// Algorithm A:
// x_q[i] = H(I || u32str(q) || u16str(i) || u8str(0xff) || SEED).
// UPDATE: I value is now generated separate from SEED. Child I values still computed the same
public Lms(LmsType lmsType, LmotsType lmotsType,
EntropyProviderTypes entropyType = EntropyProviderTypes.Random, BitString seed = null, BitString I = null)
{
var(m, h, typecode) = LmsModeMapping.GetValsFromType(lmsType);
_m = m;
_h = h;
_typecode = typecode;
var param = LmotsModeMapping.GetValsFromType(lmotsType);
_lmotsTypecode = param.typecode;
_entropyProvider = _entropyFactory.GetEntropyProvider(entropyType);
_entropyProvider.AddEntropy(seed);
SEED = _entropyProvider.GetEntropy(_m * 8);
_entropyProvider.AddEntropy(I);
_I = _entropyProvider.GetEntropy(128);
_lmots = new Lmots(lmotsType, entropyType);
_isRandom = entropyType == EntropyProviderTypes.Random;
_sha256 = new NativeFastSha2_256();
// For optimization the balance between interop calls and asynchronization
if (_h == 5)
{
_pieceSize = H5_PIECE_SIZE;
}
else if (_h == 10)
{
_pieceSize = H10_PIECE_SIZE;
}
else if (_h == 15)
{
_pieceSize = H15_PIECE_SIZE;
}
else if (_h == 20)
{
_pieceSize = H20_PIECE_SIZE;
}
else
{
_pieceSize = H25_PIECE_SIZE;
}
}
// Used for both signatures and keys
public EccDsa(ISha sha, IEccNonceProvider nonceProvider, EntropyProviderTypes entropyType)
{
Sha = sha;
_nonceProvider = nonceProvider;
_entropyProvider = _entropyFactory.GetEntropyProvider(entropyType);
}
public IEntropyProvider GetEntropyProvider(EntropyProviderTypes providerType)
{
return(new EntropyProviderLeadingZeroes(_random, MinimumLeadingZeroes));
}
public FfcDsa(ISha sha, EntropyProviderTypes entropyType = EntropyProviderTypes.Random)
{
Sha = sha;
_entropyProvider = _entropyFactory.GetEntropyProvider(entropyType);
}
public void ShouldReturnRandomCorrectProvider(EntropyProviderTypes providerType, Type expectedType)
{
var result = _subject.GetEntropyProvider(providerType);
Assert.IsInstanceOf(expectedType, result);
}
public ProvablePQGeneratorValidator(ISha sha, EntropyProviderTypes entropyType = EntropyProviderTypes.Random)
{
_sha = sha;
_entropy = _entropyFactory.GetEntropyProvider(entropyType);
}
/// <summary>
/// hashFunction should just be null
/// </summary>
/// <param name="hashFunction"></param>
/// <param name="entropyType"></param>
/// <returns></returns>
public IDsaEd GetInstance(HashFunction hashFunction, EntropyProviderTypes entropyType = EntropyProviderTypes.Random)
{
return(new EdDsa(entropyType));
}
public IDsaFfc GetInstance(HashFunction hashFunction, EntropyProviderTypes entropyType = EntropyProviderTypes.Random)
{
return(new FfcDsa(_shaFactory.GetShaInstance(hashFunction), entropyType));
}
public IHss GetInstance(int layers, LmsType[] lmsTypes, LmotsType[] lmotsTypes,
EntropyProviderTypes entropyType = EntropyProviderTypes.Random, BitString seed = null, BitString rootI = null)
{
return(new Hss(layers, lmsTypes, lmotsTypes, entropyType, seed, rootI));
}
public EdDsa(EntropyProviderTypes entropyType = EntropyProviderTypes.Random)
{
_entropyProvider = _entropyFactory.GetEntropyProvider(entropyType);
}
public IPQGeneratorValidator GetGeneratorValidator(PrimeGenMode primeGenMode, ISha sha, EntropyProviderTypes entropyType = EntropyProviderTypes.Random)
{
switch (primeGenMode)
{
case PrimeGenMode.Probable:
return(new ProbablePQGeneratorValidator(sha, entropyType));
case PrimeGenMode.Provable:
return(new ProvablePQGeneratorValidator(sha, entropyType));
default:
throw new ArgumentOutOfRangeException("Invalid PrimeGenMode provided");
}
}