add support of PEM parsing for EdDSA

README.md

@@ -2,16 +2,18 @@
 
 [![pub version](https://img.shields.io/pub/v/dart_jsonwebtoken.svg)](https://pub.dev/packages/dart_jsonwebtoken)
 
-A dart implementation of the famous javascript library `jsonwebtoken`.
+An easy to use JSON Web Token implementation in Dart (all algorithms supported).
 
 JSON Web Tokens are an open, industry standard RFC 7519 method for representing claims securely between two parties.
 
-https://jwt.io allows you to decode, verify and generate JWT.
+`dart_jsonwebtoken` allows you to sign, decode and verify JWT.
 
 ## Examples
 
 Check out the [Example File](https://github.com/jonasroussel/dart_jsonwebtoken/blob/main/example/example.dart) for a full example code of all the differents algorithms.
 
+You can also check out the [jwt.io](https://jwt.io) website for more information.
+
 ## Usage
 
 ### Import
@@ -110,9 +112,16 @@ MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEEVs/o5+uQbTjL3chynL4wXgUg2R9
 ''');
 
 
-// EdDSA (PEM parsing is not available for EdDSA keys)
-final edPrivKey = EdDSAPrivateKey([1, 42, 12, 84, ...]);
-final edPubKey = EdDSAPublicKey([1, 42, 12, 84, ...]);
+// EdDSA
+final edPrivKey = EdDSAPrivateKey.fromPEM('''-----BEGIN PRIVATE KEY-----
+MC4CAQAwBQYDK2VwBCIEICXCjBHvjArjXquUI5jo3x5SHI4ofZA2azwJ39IC/Qct
+-----END PRIVATE KEY-----
+''');
+
+final edPubKey = EdDSAPublicKey.fromPEM('''-----BEGIN PUBLIC KEY-----
+MCowBQYDK2VwAyEAEi7MNW0Q9T83UA3Rw+8DbspMgqeuxCqa2wXaWS+tHqY=
+-----END PUBLIC KEY-----
+''');
 ```
 
 ### Supported Algorithms

example/eddsa_private.pem

@@ -0,0 +1,3 @@
+-----BEGIN PRIVATE KEY-----
+MC4CAQAwBQYDK2VwBCIEICXCjBHvjArjXquUI5jo3x5SHI4ofZA2azwJ39IC/Qct
+-----END PRIVATE KEY-----

example/eddsa_public.pem

@@ -0,0 +1,3 @@
+-----BEGIN PUBLIC KEY-----
+MCowBQYDK2VwAyEAEi7MNW0Q9T83UA3Rw+8DbspMgqeuxCqa2wXaWS+tHqY=
+-----END PUBLIC KEY-----

example/example.dart

@@ -26,6 +26,10 @@ void main() {
   print('----- RSA Certificate -----');
   rsaCert();
   print('---------------------------\n');
+
+  print('----- EdDSA -----');
+  eddsa();
+  print('-----------------\n');
 }
 
 // HMAC SHA-256 algorithm
@@ -279,3 +283,45 @@ void rsaCert() {
     }
   }
 }
+
+void eddsa() {
+  String token;
+
+  /* Sign */ {
+    // Create a json web token
+    final jwt = JWT(
+      {
+        'id': 123,
+        'server': {
+          'id': '3e4fc296',
+          'loc': 'euw-2',
+        }
+      },
+      issuer: 'https://github.com/jonasroussel/dart_jsonwebtoken',
+    );
+
+    // Sign it
+    final privPem = File('./example/eddsa_private.pem').readAsStringSync();
+    final key = EdDSAPrivateKey.fromPEM(privPem);
+
+    token = jwt.sign(key, algorithm: JWTAlgorithm.EdDSA);
+
+    print('Signed token: $token\n');
+  }
+
+  /* Verify */ {
+    try {
+      // Verify a token
+      final pem = File('./example/eddsa_public.pem').readAsStringSync();
+      final key = EdDSAPublicKey.fromPEM(pem);
+
+      final jwt = JWT.verify(token, key);
+
+      print('Payload: ${jwt.payload}');
+    } on JWTExpiredException {
+      print('jwt expired');
+    } on JWTException catch (ex) {
+      print(ex.message); // ex: invalid signature
+    }
+  }
+}

lib/src/key_parser.dart

@@ -4,6 +4,7 @@ import 'dart:typed_data';
 import 'package:pointycastle/asn1/object_identifiers.dart';
 import 'package:pointycastle/pointycastle.dart';
 import 'package:pointycastle/ecc/ecc_fp.dart' as ecc_fp;
+import 'package:ed25519_edwards/ed25519_edwards.dart' as ed;
 
 import 'helpers.dart';
 
@@ -245,6 +246,38 @@ abstract class KeyParser {
     return pubKey;
   }
 
+  //---------------//
+  // EdDSA Parsing //
+  //---------------//
+
+  static ed.PrivateKey edPrivateKeyFromPEM(String pem) {
+    final bytes = bytesFromPEM(pem);
+    return edPrivateKey(bytes);
+  }
+
+  static ed.PrivateKey edPrivateKey(Uint8List bytes) {
+    var asn1Parser = ASN1Parser(bytes);
+    var topLevelSeq = asn1Parser.nextObject() as ASN1Sequence;
+
+    var octetString = topLevelSeq.elements!.elementAt(2) as ASN1OctetString;
+
+    return ed.newKeyFromSeed(octetString.valueBytes!.sublist(2));
+  }
+
+  static ed.PublicKey edPublicKeyFromPEM(String pem) {
+    final bytes = bytesFromPEM(pem);
+    return edPublicKey(bytes);
+  }
+
+  static ed.PublicKey edPublicKey(Uint8List bytes) {
+    var asn1Parser = ASN1Parser(bytes);
+    var topLevelSeq = asn1Parser.nextObject() as ASN1Sequence;
+
+    var bitString = topLevelSeq.elements!.elementAt(1) as ASN1BitString;
+
+    return ed.PublicKey(bitString.valueBytes!.sublist(1));
+  }
+
   //--------------//
   // PEM to Bytes //
   //--------------//

lib/src/keys.dart

@@ -115,18 +115,19 @@ class ECPublicKey extends JWTKey {
 
 /// For EdDSA algorithm, in sign method
 class EdDSAPrivateKey extends JWTKey {
-  late ed.PrivateKey key;
+  ed.PrivateKey key;
 
-  EdDSAPrivateKey(List<int> bytes) {
-    key = ed.PrivateKey(bytes);
-  }
+  EdDSAPrivateKey(List<int> bytes) : key = ed.PrivateKey(bytes);
+
+  EdDSAPrivateKey.fromPEM(String pem)
+      : key = KeyParser.edPrivateKeyFromPEM(pem);
 }
 
 /// For EdDSA algorithm, in verify method
 class EdDSAPublicKey extends JWTKey {
-  late ed.PublicKey key;
+  ed.PublicKey key;
 
-  EdDSAPublicKey(List<int> bytes) {
-    key = ed.PublicKey(bytes);
-  }
+  EdDSAPublicKey(List<int> bytes) : key = ed.PublicKey(bytes);
+
+  EdDSAPublicKey.fromPEM(String pem) : key = KeyParser.edPublicKeyFromPEM(pem);
 }

test/sign_test.dart

@@ -1,4 +1,3 @@
-import 'dart:convert';
 import 'dart:math';
 
 import 'package:dart_jsonwebtoken/dart_jsonwebtoken.dart';
@@ -43,12 +42,9 @@ MHQCAQEEINCRiJnNDnzfo2So2tWY4AIuzeC2ZBp/hmMDcZz3Fh45oAcGBSuBBAAK
 oUQDQgAE0aELkvG/Xeo5y6o0WXRAjlediLptGz7Q8zjDmpGFXkKBYZ6IiL7JJ2Tk
 cHzd83bmeUeGX33RGTYFPXs5t/VBnw==
 -----END EC PRIVATE KEY-----''');
-final edKey = EdDSAPrivateKey(
-  base64Decode(
-    'nWGxne/9WmC6hEr0kuwsxERJxWl7MmkZcDusAxyuf2DXWpgBgrEKt9VL/' +
-        'tPJZAc6DuFy89qmIyWvAhpo9wdRGg==',
-  ),
-);
+final edKey = EdDSAPrivateKey.fromPEM('''-----BEGIN PRIVATE KEY-----
+MC4CAQAwBQYDK2VwBCIEICXCjBHvjArjXquUI5jo3x5SHI4ofZA2azwJ39IC/Qct
+-----END PRIVATE KEY-----''');
 
 class MockRSAAlgorithm extends RSAAlgorithm {
   MockRSAAlgorithm(String name) : super(name, Random(42));
@@ -218,7 +214,7 @@ void main() {
 
         final expectedToken = 'eyJhbGciOiJFZERTQSIsInR5cCI6IkpXVCJ9' +
             '.eyJmb28iOiJiYXIifQ' +
-            '.8tRIxs_o_isQItc2FtzA34Ah-EEvBj7Fw6lKh2tD53IOx5CinBM36yIGo2TDHNmm-ElATCdnMisUKt_UJ5pTAg';
+            '.6Bw5vvdpJ_kgDwidU1l7aagtKCD9-QIJxrz44HXxtc6OJoOmImNko0dgXYpTtXhcEuX7vamSR5JPfGP1Q9d9DA';
 
         expect(token, equals(expectedToken));
       });

test/verify_test.dart

@@ -1,5 +1,3 @@
-import 'dart:convert';
-
 import 'package:dart_jsonwebtoken/dart_jsonwebtoken.dart';
 import 'package:test/test.dart';
 
@@ -21,9 +19,9 @@ final secp256kKey = ECPublicKey('''-----BEGIN PUBLIC KEY-----
 MFYwEAYHKoZIzj0CAQYFK4EEAAoDQgAE0aELkvG/Xeo5y6o0WXRAjlediLptGz7Q
 8zjDmpGFXkKBYZ6IiL7JJ2TkcHzd83bmeUeGX33RGTYFPXs5t/VBnw==
 -----END PUBLIC KEY-----''');
-final edKey = EdDSAPublicKey(
-  base64Decode('11qYAYKxCrfVS/7TyWQHOg7hcvPapiMlrwIaaPcHURo='),
-);
+final edKey = EdDSAPublicKey.fromPEM('''-----BEGIN PUBLIC KEY-----
+MCowBQYDK2VwAyEAEi7MNW0Q9T83UA3Rw+8DbspMgqeuxCqa2wXaWS+tHqY=
+-----END PUBLIC KEY-----''');
 
 void main() {
   group('Verify a JWT', () {
@@ -244,7 +242,7 @@ void main() {
       test('.verify EdDSA', () {
         final token = 'eyJhbGciOiJFZERTQSIsInR5cCI6IkpXVCJ9' +
             '.eyJmb28iOiJiYXIifQ' +
-            '.8tRIxs_o_isQItc2FtzA34Ah-EEvBj7Fw6lKh2tD53IOx5CinBM36yIGo2TDHNmm-ElATCdnMisUKt_UJ5pTAg';
+            '.6Bw5vvdpJ_kgDwidU1l7aagtKCD9-QIJxrz44HXxtc6OJoOmImNko0dgXYpTtXhcEuX7vamSR5JPfGP1Q9d9DA';
 
         final jwt = JWT.tryVerify(token, edKey);