Upgrade Dependencies and remove Warnings

Author: konstantinullrich

lib/src/rsa/private_key.dart

@@ -20,7 +20,7 @@ class RSAPrivateKey implements PrivateKey {
     final topLevelSeq = asn1Parser.nextObject() as ASN1Sequence;
     final privateKey = topLevelSeq.elements[2];
 
-    asn1Parser = ASN1Parser(privateKey.contentBytes()!);
+    asn1Parser = ASN1Parser(privateKey.contentBytes());
     final pkSeq = asn1Parser.nextObject() as ASN1Sequence;
 
     final modulus = pkSeq.elements[1] as ASN1Integer;
@@ -29,8 +29,8 @@ class RSAPrivateKey implements PrivateKey {
     final q = pkSeq.elements[5] as ASN1Integer;
 
     _privateKey = pointy.RSAPrivateKey(
-        modulus.valueAsBigInteger!,
-        privateExponent.valueAsBigInteger!,
+        modulus.valueAsBigInteger,
+        privateExponent.valueAsBigInteger,
         p.valueAsBigInteger,
         q.valueAsBigInteger);
   }

lib/src/rsa/public_key.dart

@@ -20,13 +20,13 @@ class RSAPublicKey implements PublicKey {
     final topLevelSeq = asn1Parser.nextObject() as ASN1Sequence;
     final publicKeyBitString = topLevelSeq.elements[1];
 
-    final publicKeyAsn = ASN1Parser(publicKeyBitString.contentBytes()!);
+    final publicKeyAsn = ASN1Parser(publicKeyBitString.contentBytes());
     final publicKeySeq = publicKeyAsn.nextObject() as ASN1Sequence;
     final modulus = publicKeySeq.elements[0] as ASN1Integer;
     final exponent = publicKeySeq.elements[1] as ASN1Integer;
 
     _publicKey = pointy.RSAPublicKey(
-        modulus.valueAsBigInteger!, exponent.valueAsBigInteger!);
+        modulus.valueAsBigInteger, exponent.valueAsBigInteger);
   }
 
   /// Create an [RSAPublicKey] from the given PEM-String.

pubspec.yaml

@@ -1,17 +1,17 @@
 name: crypton
 description: A simple Dart library for asymmetric encryption and digital signatures
-version: 2.1.0
+version: 2.2.0
 homepage: https://github.com/konstantinullrich
 repository: https://github.com/konstantinullrich/crypton
 issue_tracker: https://github.com/konstantinullrich/crypton/issues
 
 environment:
-  sdk: '>=2.14.0 <3.0.0'
+  sdk: ^3.0.0
 
 dependencies:
-  pointycastle: ^3.6.2
-  asn1lib: ^1.2.2
+  pointycastle: ^3.7.3
+  asn1lib: ^1.5.0
 
 dev_dependencies:
-  lints: ^1.0.1
-  test: ^1.21.4
+  lints: ^2.1.1
+  test: ^1.24.4