需添加依赖:pointycastle
参考链接:https://github.com/bcgit/pc-dart/issues/165
Dart
import 'dart:convert';
import 'dart:typed_data';
import 'package:pointycastle/pointycastle.dart';
import 'package:pointycastle/src/platform_check/platform_check.dart';
import "package:pointycastle/export.dart";
class RSAUtils {
///
/// [生成RSA公私密钥对](https://github.com/bcgit/pc-dart/blob/master/tutorials/rsa.md)
///
static AsymmetricKeyPair<RSAPublicKey, RSAPrivateKey> generateKeyPair(
{int bitLength = 2048}) {
final keyGen = RSAKeyGenerator();
//初始化
final secureRandom = SecureRandom('Fortuna')
..seed(KeyParameter(
Platform.instance.platformEntropySource().getBytes(32)));
keyGen.init(ParametersWithRandom(
RSAKeyGeneratorParameters(BigInt.parse('65537'), bitLength, 64),
secureRandom));
final pair = keyGen.generateKeyPair();
final myPublic = pair.publicKey as RSAPublicKey;
final myPrivate = pair.privateKey as RSAPrivateKey;
return AsymmetricKeyPair<RSAPublicKey, RSAPrivateKey>(myPublic, myPrivate);
}
/// https://github.com/bcgit/pc-dart/blob/master/tutorials/asn1.md
/// https://github.com/bcgit/pc-dart/issues/165
static String publicKey2PemString(RSAPublicKey publicKey) {
const beginPublicKey = '-----BEGIN PUBLIC KEY-----';
const endPublicKey = '-----END PUBLIC KEY-----';
// Create the top level sequence
var topLevelSeq = ASN1Sequence();
// Create the sequence holding the algorithm information
var algorithmSeq = ASN1Sequence();
var paramsAsn1Obj = ASN1Object.fromBytes(Uint8List.fromList([0x5, 0x0]));
algorithmSeq.add(ASN1ObjectIdentifier.fromIdentifierString('1.2.840.113549.1.1.1'));
algorithmSeq.add(paramsAsn1Obj);
// Create the constructed ASN1BitString
/*var modulus = ASN1Integer(publicKey.modulus);
var exponent = ASN1Integer(publicKey.exponent);
var publicKeySeqBitString = ASN1BitString(elements : [modulus, exponent], tag: ASN1Tags.BIT_STRING_CONSTRUCTED);*/
var keySequence = ASN1Sequence();
keySequence.add(ASN1Integer(publicKey.modulus));
keySequence.add(ASN1Integer(publicKey.exponent));
keySequence.encode(encodingRule: ASN1EncodingRule.ENCODING_DER);
var publicKeySeqBitString = ASN1BitString(stringValues: keySequence.encodedBytes!);
// Add ASN1 objects to the top level sequence
topLevelSeq.add(algorithmSeq);
topLevelSeq.add(publicKeySeqBitString);
// topLevelSeq.encode();
// Encode base64
var dataBase64 = base64.encode(topLevelSeq.encodedBytes!);
var chunks = _chunk(dataBase64, 64);
return '$beginPublicKey\n${chunks.join('\n')}\n$endPublicKey';
}
static List<String> _chunk(String s, int chunkSize) {
var chunked = <String>[];
for (var i = 0; i < s.length; i += chunkSize) {
var end = (i + chunkSize < s.length) ? i + chunkSize : s.length;
chunked.add(s.substring(i, end));
}
return chunked;
}
}