+static const unsigned char base64_tab[256] = {
+ 255, 255, 255, 255, 255, 255, 255, 255, /* 00-07 */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* 08-0f */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* 10-17 */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* 18-1f */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* 20-2f */
+ 255, 255, 255, 62, 255, 255, 255, 63, /* 28-2f */
+ 52 , 53, 54, 55, 56, 57, 58, 59, /* 30-37 */
+ 60 , 61, 255, 255, 255, 255, 255, 255, /* 38-3f */
+ 255, 0, 1, 2, 3, 4, 5, 6, /* 40-47 */
+ 7 , 8, 9, 10, 11, 12, 13, 14, /* 48-4f */
+ 15 , 16, 17, 18, 19, 20, 21, 22, /* 50-57 */
+ 23 , 24, 25, 255, 255, 255, 255, 255, /* 58-5f */
+ 255, 26, 27, 28, 29, 30, 31, 32, /* 60-6f */
+ 33 , 34, 35, 36, 37, 38, 39, 40, /* 68-6f */
+ 41 , 42, 43, 44, 45, 46, 47, 48, /* 70-77 */
+ 49 , 50, 51, 255, 255, 255, 255, 255, /* 78-7f */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* 80-87 */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* 88-8f */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* 90-97 */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* 98-9f */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* a0-a7 */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* a8-af */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* b0-b7 */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* b8-bf */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* c0-c7 */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* c8-cf */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* d0-d7 */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* d8-df */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* e0-e7 */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* e8-ef */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* f0-f7 */
+ 255, 255, 255, 255, 255, 255, 255, 255, /* f8-ff */
+};