Adds new alphabet to Base64Codec

Author: dipu-bd

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 2.1.1
+
+- Adds new alphabet to `Base64Codec`: [bcrypt][https://en.wikipedia.org/wiki/Bcrypt#base64_encoding_alphabet]
+
 # 2.1.0
 
 - Adds more alphabets to `Base32Codec`. Additional alphabets are:

lib/src/codecs/base64.dart

@@ -23,7 +23,6 @@ const _base64EncodingRfc4648 = [
   0x77, 0x78, 0x79, 0x7a, 0x30, 0x31, 0x32, 0x33,
   0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x2b, 0x2f,
 ];
-
 const _base64EncodingRfc4648UrlSafe = [
   0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, //
   0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50,
@@ -34,7 +33,6 @@ const _base64EncodingRfc4648UrlSafe = [
   0x77, 0x78, 0x79, 0x7a, 0x30, 0x31, 0x32, 0x33,
   0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x2d, 0x5f,
 ];
-
 const _base64DecodingRfc4648 = [
   __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, //
   __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
@@ -45,6 +43,26 @@ const _base64DecodingRfc4648 = [
   43, 44, 45, 46, 47, 48, 49, 50, 51, __, __, __, __, __, __, __, __, __, __,
 ];
 
+const _base64EncodingBcrypt = [
+  0x2e, 0x2f, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, //
+  0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e,
+  0x4f, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56,
+  0x57, 0x58, 0x59, 0x5a, 0x61, 0x62, 0x63, 0x64,
+  0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c,
+  0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0x73, 0x74,
+  0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x30, 0x31,
+  0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
+];
+const _base64DecodingBcrypt = [
+  __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, //
+  __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __, __,
+  __, __, __, __, __, __, __, __, 00, 01, 54, 55, 56, 57, 58, 59, 60, 61, 62,
+  63, __, __, __, __, __, __, __, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12,
+  13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, __, __, __, __,
+  __, __, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44,
+  45, 46, 47, 48, 49, 50, 51, 52, 53, __, __, __, __, __, __, __, __, __, __,
+];
+
 // ========================================================
 // Base-64 Codec
 // ========================================================
@@ -142,4 +160,23 @@ class Base64Codec extends HashlibCodec {
       alphabet: _base64DecodingRfc4648,
     ),
   );
+
+  /// Codec instance to encode and decode 8-bit integer sequence to 6-bit
+  /// Base-64 character sequence using the alphabet described in
+  /// [Bcrypt](https://en.wikipedia.org/wiki/Bcrypt#base64_encoding_alphabet):
+  /// ```
+  /// ./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789
+  /// ```
+  ///
+  /// It is not padded.
+  static const Base64Codec bcrypt = Base64Codec._(
+    encoder: AlphabetEncoder(
+      bits: 6,
+      alphabet: _base64EncodingBcrypt,
+    ),
+    decoder: AlphabetDecoder(
+      bits: 6,
+      alphabet: _base64DecodingBcrypt,
+    ),
+  );
 }

pubspec.yaml

@@ -1,7 +1,7 @@
 name: hashlib_codecs
 description: Fast and error resilient codecs. Currently supporting Binary(Base2), Hexadecimal(Base16), Base32, Base64, BigInt.
 homepage: https://github.com/bitanon/hashlib_codecs
-version: 2.1.0
+version: 2.1.1
 
 environment:
   sdk: '>=2.14.0 <4.0.0'

scripts/alphabet_maker.py

@@ -48,7 +48,12 @@ def fwd(s):
 # print("z-base-32 reversed", end=":")
 # rev(b"ybndrfg8ejkmcpqxot1uwisza345h769")
 
-print("word-safe", end=":")
-fwd(b"23456789CFGHJMPQRVWXcfghjmpqrvwx")
-print("word-safe reversed", end=":")
-rev(b"23456789CFGHJMPQRVWXcfghjmpqrvwx")
+# print("word-safe", end=":")
+# fwd(b"23456789CFGHJMPQRVWXcfghjmpqrvwx")
+# print("word-safe reversed", end=":")
+# rev(b"23456789CFGHJMPQRVWXcfghjmpqrvwx")
+
+print("base64 bcrypt", end=":")
+fwd(b"./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789")
+print("base64 bcrypt reversed", end=":")
+rev(b"./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789")

test/base64_test.dart

@@ -105,6 +105,14 @@ void main() {
         expect(fromBase64(r), equals(b), reason: 'length $i');
       }
     });
+    test('[bcrypt] encoding <-> decoding', () {
+      for (int i = 0; i < 100; ++i) {
+        var b = randomBytes(i);
+        var r = toBase64(b, codec: Base64Codec.bcrypt);
+        var a = fromBase64(r, codec: Base64Codec.bcrypt);
+        expect(a, equals(b), reason: 'length $i');
+      }
+    });
     group('decoding with invalid chars', () {
       test('Hashlib!', () {
         try {