50 lines
1.3 KiB
Dart
50 lines
1.3 KiB
Dart
// See file LICENSE for more information.
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library impl.key_generator.ec_key_generator;
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import 'package:pointycastle/api.dart';
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import 'package:pointycastle/ecc/api.dart';
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import 'package:pointycastle/key_generators/api.dart';
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import 'package:pointycastle/src/registry/registry.dart';
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/// Abstract [CipherParameters] to init an ECC key generator.
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class ECKeyGenerator implements KeyGenerator {
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static final FactoryConfig factoryConfig =
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StaticFactoryConfig(KeyGenerator, 'EC', () => ECKeyGenerator());
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late ECDomainParameters _params;
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late SecureRandom _random;
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@override
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String get algorithmName => 'EC';
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@override
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void init(CipherParameters params) {
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ECKeyGeneratorParameters ecparams;
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if (params is ParametersWithRandom) {
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_random = params.random;
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ecparams = params.parameters as ECKeyGeneratorParameters;
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} else {
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_random = SecureRandom();
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ecparams = params as ECKeyGeneratorParameters;
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}
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_params = ecparams.domainParameters;
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}
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@override
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AsymmetricKeyPair<ECPublicKey, ECPrivateKey> generateKeyPair() {
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var n = _params.n;
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var nBitLength = n.bitLength;
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BigInt? d;
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do {
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d = _random.nextBigInteger(nBitLength);
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} while (d == BigInt.zero || (d >= n));
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var Q = _params.G * d;
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return AsymmetricKeyPair(ECPublicKey(Q, _params), ECPrivateKey(d, _params));
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}
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}
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