117 lines
2.2 KiB
Dart
117 lines
2.2 KiB
Dart
import 'dart:convert';
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import 'dart:typed_data';
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String base64UrlNoPadEncode(List<int> bytes) {
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var x = base64Url.encode(bytes);
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while (x.endsWith('=')) {
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x = x.substring(0, x.length - 1);
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}
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return x;
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}
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Uint8List base64UrlNoPadDecode(String source) {
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source = base64.normalize(source);
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return base64.decode(source);
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}
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abstract class EncodedString {
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late String contents;
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EncodedString(String s) {
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validate(s);
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contents = s;
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}
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EncodedString.encode(List<int> b) {
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var s = base64UrlNoPadEncode(b);
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validate(s);
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contents = s;
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}
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int encodedLength();
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int decodedLength();
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void validate(String s) {
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var d = base64UrlNoPadDecode(s);
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if (d.length != decodedLength()) {
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throw Exception("length ${s.length} should be ${encodedLength()}");
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}
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}
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Uint8List decode() {
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return base64UrlNoPadDecode(contents);
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}
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@override
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String toString() {
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return contents;
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}
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static T fromString<T extends EncodedString>(String s) {
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switch (T) {
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case FixedEncodedString32:
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return FixedEncodedString32(s) as T;
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case FixedEncodedString43:
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return FixedEncodedString43(s) as T;
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case FixedEncodedString86:
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return FixedEncodedString86(s) as T;
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default:
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throw UnimplementedError();
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}
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}
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}
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class FixedEncodedString32 extends EncodedString {
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FixedEncodedString32(String s) : super(s);
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@override
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int encodedLength() {
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return 32;
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}
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@override
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int decodedLength() {
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return 24;
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}
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String get json {
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return toString();
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}
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FixedEncodedString32.fromJson(dynamic json) : this(json as String);
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}
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class FixedEncodedString43 extends EncodedString {
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FixedEncodedString43(String s) : super(s);
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@override
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int encodedLength() {
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return 43;
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}
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@override
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int decodedLength() {
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return 32;
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}
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String get json {
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return toString();
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}
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FixedEncodedString43.fromJson(dynamic json) : this(json as String);
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}
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class FixedEncodedString86 extends EncodedString {
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FixedEncodedString86(String s) : super(s);
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@override
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int encodedLength() {
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return 86;
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}
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@override
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int decodedLength() {
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return 64;
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}
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String get json {
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return toString();
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}
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FixedEncodedString86.fromJson(dynamic json) : this(json as String);
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}
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