# 2.10.2. rfc2045¶

RFC 2045 Multipurpose Internet Mail Extensions (MIME) 主要定义了base64相关知识

The Base64 Alphabet:

Value Encoding  Value Encoding  Value Encoding  Value Encoding
0 A            17 R            34 i            51 z
1 B            18 S            35 j            52 0
2 C            19 T            36 k            53 1
3 D            20 U            37 l            54 2
4 E            21 V            38 m            55 3
5 F            22 W            39 n            56 4
6 G            23 X            40 o            57 5
7 H            24 Y            41 p            58 6
8 I            25 Z            42 q            59 7
9 J            26 a            43 r            60 8
10 K            27 b            44 s            61 9
11 L            28 c            45 t            62 +
12 M            29 d            46 u            63 /
13 N            30 e            47 v
14 O            31 f            48 w         (pad) =
15 P            32 g            49 x
16 Q            33 h            50 y