| | 1 | | namespace NLightning.Infrastructure.Transport.Handshake.States; |
| | 2 | |
|
| | 3 | | using Common.Utils; |
| | 4 | | using Crypto.Factories; |
| | 5 | | using Crypto.Functions; |
| | 6 | | using Crypto.Hashes; |
| | 7 | | using Crypto.Interfaces; |
| | 8 | | using Crypto.Primitives; |
| | 9 | | using Domain.Crypto.Constants; |
| | 10 | |
|
| | 11 | | /// <summary> |
| | 12 | | /// A SymmetricState object contains a CipherState plus ck (a chaining |
| | 13 | | /// key of HashLen bytes) and h (a hash output of HashLen bytes). |
| | 14 | | /// </summary> |
| | 15 | | internal sealed class SymmetricState : IDisposable |
| | 16 | | { |
| | 17 | | private readonly ICryptoProvider _cryptoProvider; |
| 96 | 18 | | private readonly Sha256 _sha256 = new(); |
| 96 | 19 | | private readonly Hkdf _hkdf = new(); |
| 96 | 20 | | private readonly CipherState _state = new(); |
| | 21 | | private readonly SecureMemory _ck; |
| | 22 | | private readonly byte[] _h; |
| | 23 | |
|
| | 24 | | private bool _disposed; |
| | 25 | |
|
| | 26 | | /// <summary> |
| | 27 | | /// Initializes a new SymmetricState with an |
| | 28 | | /// arbitrary-length protocolName byte sequence. |
| | 29 | | /// </summary> |
| 96 | 30 | | public SymmetricState(ReadOnlySpan<byte> protocolName) |
| | 31 | | { |
| 96 | 32 | | _cryptoProvider = CryptoFactory.GetCryptoProvider(); |
| 96 | 33 | | _ck = new SecureMemory(CryptoConstants.SHA256_HASH_LEN); |
| 96 | 34 | | _h = new byte[CryptoConstants.SHA256_HASH_LEN]; |
| | 35 | |
|
| 96 | 36 | | if (protocolName.Length <= CryptoConstants.SHA256_HASH_LEN) |
| | 37 | | { |
| 0 | 38 | | protocolName.CopyTo(_h); |
| | 39 | | } |
| | 40 | | else |
| | 41 | | { |
| 96 | 42 | | _sha256.AppendData(protocolName); |
| 96 | 43 | | _sha256.GetHashAndReset(_h); |
| | 44 | | } |
| | 45 | |
|
| 96 | 46 | | _h.CopyTo(_ck); |
| 96 | 47 | | } |
| | 48 | |
|
| | 49 | | /// <summary> |
| | 50 | | /// Sets ck, tempK = HKDF(ck, inputKeyMaterial, 2). |
| | 51 | | /// If HashLen is 64, then truncates tempK to 32 bytes. |
| | 52 | | /// Calls InitializeKey(tempK). |
| | 53 | | /// </summary> |
| | 54 | | public void MixKey(ReadOnlySpan<byte> inputKeyMaterial) |
| | 55 | | { |
| 180 | 56 | | ExceptionUtils.ThrowIfDisposed(_disposed, nameof(Hkdf)); |
| | 57 | |
|
| 180 | 58 | | var length = inputKeyMaterial.Length; |
| 180 | 59 | | if (length != 0 && length != CryptoConstants.PRIVKEY_LEN) |
| | 60 | | { |
| 0 | 61 | | throw new ArgumentOutOfRangeException(nameof(inputKeyMaterial), $"Length should be either 0 or {CryptoConsta |
| | 62 | | } |
| | 63 | |
|
| 180 | 64 | | Span<byte> output = stackalloc byte[2 * CryptoConstants.SHA256_HASH_LEN]; |
| 180 | 65 | | _hkdf.ExtractAndExpand2(_ck, inputKeyMaterial, output); |
| | 66 | |
|
| 180 | 67 | | output[..CryptoConstants.SHA256_HASH_LEN].CopyTo(_ck); |
| | 68 | |
|
| 180 | 69 | | var tempK = output.Slice(CryptoConstants.SHA256_HASH_LEN, CryptoConstants.PRIVKEY_LEN); |
| 180 | 70 | | _state.InitializeKeyAndChainingKey(tempK, _ck); |
| 180 | 71 | | } |
| | 72 | |
|
| | 73 | | /// <summary> |
| | 74 | | /// Sets h = HASH(h || data). |
| | 75 | | /// </summary> |
| | 76 | | public void MixHash(ReadOnlySpan<byte> data) |
| | 77 | | { |
| 552 | 78 | | ExceptionUtils.ThrowIfDisposed(_disposed, nameof(Hkdf)); |
| | 79 | |
|
| 552 | 80 | | _sha256.AppendData(_h); |
| 552 | 81 | | _sha256.AppendData(data); |
| 552 | 82 | | _sha256.GetHashAndReset(_h); |
| 552 | 83 | | } |
| | 84 | |
|
| | 85 | | /// <summary> |
| | 86 | | /// Sets ck, tempH, tempK = HKDF(ck, inputKeyMaterial, 3). |
| | 87 | | /// Calls MixHash(tempH). |
| | 88 | | /// If HashLen is 64, then truncates tempK to 32 bytes. |
| | 89 | | /// Calls InitializeKey(tempK). |
| | 90 | | /// </summary> |
| | 91 | | public void MixKeyAndHash(ReadOnlySpan<byte> inputKeyMaterial) |
| | 92 | | { |
| 0 | 93 | | ExceptionUtils.ThrowIfDisposed(_disposed, nameof(Hkdf)); |
| | 94 | |
|
| 0 | 95 | | var length = inputKeyMaterial.Length; |
| 0 | 96 | | if (length != 0 && length != CryptoConstants.PRIVKEY_LEN) |
| | 97 | | { |
| 0 | 98 | | throw new ArgumentOutOfRangeException(nameof(inputKeyMaterial), $"Length should be either 0 or {CryptoConsta |
| | 99 | | } |
| | 100 | |
|
| 0 | 101 | | Span<byte> output = stackalloc byte[3 * CryptoConstants.SHA256_HASH_LEN]; |
| 0 | 102 | | _hkdf.ExtractAndExpand3(_ck, inputKeyMaterial, output); |
| | 103 | |
|
| 0 | 104 | | output[..CryptoConstants.SHA256_HASH_LEN].CopyTo(_ck); |
| | 105 | |
|
| 0 | 106 | | var tempH = output.Slice(CryptoConstants.SHA256_HASH_LEN, CryptoConstants.SHA256_HASH_LEN); |
| 0 | 107 | | var tempK = output.Slice(2 * CryptoConstants.SHA256_HASH_LEN, CryptoConstants.PRIVKEY_LEN); |
| | 108 | |
|
| 0 | 109 | | MixHash(tempH); |
| 0 | 110 | | _state.InitializeKeyAndChainingKey(tempK, _ck); |
| 0 | 111 | | } |
| | 112 | |
|
| | 113 | | /// <summary> |
| | 114 | | /// Returns h. This function should only be called at the end of |
| | 115 | | /// a handshake, i.e. after the Split() function has been called. |
| | 116 | | /// </summary> |
| | 117 | | public byte[] GetHandshakeHash() |
| | 118 | | { |
| 32 | 119 | | ExceptionUtils.ThrowIfDisposed(_disposed, nameof(Hkdf)); |
| | 120 | |
|
| 32 | 121 | | return _h; |
| | 122 | | } |
| | 123 | |
|
| | 124 | | /// <summary> |
| | 125 | | /// Sets ciphertext = EncryptWithAd(h, plaintext), |
| | 126 | | /// calls MixHash(ciphertext), and returns ciphertext. |
| | 127 | | /// </summary> |
| | 128 | | public int EncryptAndHash(ReadOnlySpan<byte> plaintext, Span<byte> ciphertext) |
| | 129 | | { |
| 108 | 130 | | ExceptionUtils.ThrowIfDisposed(_disposed, nameof(Hkdf)); |
| | 131 | |
|
| 108 | 132 | | var bytesWritten = _state.EncryptWithAd(_h, plaintext, ciphertext); |
| 108 | 133 | | MixHash(ciphertext[..bytesWritten]); |
| | 134 | |
|
| 108 | 135 | | return bytesWritten; |
| | 136 | | } |
| | 137 | |
|
| | 138 | | /// <summary> |
| | 139 | | /// Sets plaintext = DecryptWithAd(h, ciphertext), |
| | 140 | | /// calls MixHash(ciphertext), and returns plaintext. |
| | 141 | | /// </summary> |
| | 142 | | public int DecryptAndHash(ReadOnlySpan<byte> ciphertext, Span<byte> plaintext) |
| | 143 | | { |
| 116 | 144 | | ExceptionUtils.ThrowIfDisposed(_disposed, nameof(Hkdf)); |
| | 145 | |
|
| 116 | 146 | | var bytesRead = _state.DecryptWithAd(_h, ciphertext, plaintext); |
| 100 | 147 | | MixHash(ciphertext); |
| | 148 | |
|
| 100 | 149 | | return bytesRead; |
| | 150 | | } |
| | 151 | |
|
| | 152 | | /// <summary> |
| | 153 | | /// Returns a pair of CipherState objects for encrypting transport messages. |
| | 154 | | /// </summary> |
| | 155 | | public (CipherState c1, CipherState c2) Split() |
| | 156 | | { |
| 32 | 157 | | ExceptionUtils.ThrowIfDisposed(_disposed, nameof(Hkdf)); |
| | 158 | |
|
| 32 | 159 | | Span<byte> output = stackalloc byte[2 * CryptoConstants.SHA256_HASH_LEN]; |
| 32 | 160 | | _hkdf.ExtractAndExpand2(_ck, null, output); |
| | 161 | |
|
| 32 | 162 | | var tempK1 = output[..CryptoConstants.PRIVKEY_LEN]; |
| 32 | 163 | | var tempK2 = output.Slice(CryptoConstants.SHA256_HASH_LEN, CryptoConstants.PRIVKEY_LEN); |
| | 164 | |
|
| 32 | 165 | | var c1 = new CipherState(); |
| 32 | 166 | | var c2 = new CipherState(); |
| | 167 | |
|
| 32 | 168 | | c1.InitializeKeyAndChainingKey(tempK1, _ck); |
| 32 | 169 | | c2.InitializeKeyAndChainingKey(tempK2, _ck); |
| | 170 | |
|
| 32 | 171 | | return (c1, c2); |
| | 172 | | } |
| | 173 | |
|
| | 174 | | /// <summary> |
| | 175 | | /// Returns true if k and ck are non-empty, false otherwise. |
| | 176 | | /// </summary> |
| | 177 | | public bool HasKeys() |
| | 178 | | { |
| 244 | 179 | | ExceptionUtils.ThrowIfDisposed(_disposed, nameof(Hkdf)); |
| | 180 | |
|
| 244 | 181 | | return _state.HasKeys(); |
| | 182 | | } |
| | 183 | |
|
| | 184 | | public void Dispose() |
| | 185 | | { |
| 128 | 186 | | if (_disposed) |
| | 187 | | { |
| 32 | 188 | | return; |
| | 189 | | } |
| | 190 | |
|
| 96 | 191 | | _ck.Dispose(); |
| 96 | 192 | | _state.Dispose(); |
| 96 | 193 | | _hkdf.Dispose(); |
| 96 | 194 | | _sha256.Dispose(); |
| 96 | 195 | | _cryptoProvider.Dispose(); |
| | 196 | |
|
| 96 | 197 | | _disposed = true; |
| 96 | 198 | | } |
| | 199 | | } |