First of all, it's great to see you here Alex. Welcome.

--- In vmu-dev@egroups.com, "Alexander Villagran" <villagra@d...>
wrote:
> The encoding format is as follows:
> Here is Perl code to convert the modified Base64 format. After it
is
> decoded, you then pass it through a standard Base64 decoder.

This is all and well (I had expected some kind of base64 reordering of
this kind), however this is hardly the entire truth. Before being
encoded with this modified base64, there must be some other encoding
done on the binary data. For example, if I take an attachment of a 4K
large file consisting only of zeroes and run it through your Perl
function (and then a base64 decoder), this is what I get:

000000 51 a8 f3 b7 cc 71 77 b6 f9 47 12 ae 4f d1 1e 55
000010 b6 60 8a 42 aa 5a 7f 4f ee be ee 7c 6a f5 24 e8
000020 71 b2 b6 a5 70 6a fb 29 e1 05 cb a7 38 24 1f 65
000030 2f 0e 3f 36 5b 33 2e c4 7e 1e f6 e6 b7 b9 bc 63
000040 8a e5 c6 0d 95 49 b0 dd 54 22 2a 03 a5 66 cb b2
000050 73 d0 9b b2 0d 28 d6 84 0b bf f1 f4 66 b7 c4 c6
000060 3a cb 4d 6b 50 6a 59 a3 f3 72 16 20 17 40 eb 82
000070 45 85 5c d3 75 a9 a7 a1 79 5a 36 98 37 6e f5 d1
000080 59 ae dc fe 49 f7 52 39 b3 5b 96 bc 89 94 43 0f
000090 a9 51 e3 3e dd 79 21 9c 6b 85 4c fc 5c 90 5b b9
0000a0 73 f0 6e 61 f7 2f ab 58 fd a1 d4 8f 09 94 c0 6b
0000b0 a4 bf a1 5f ad 07 36 ab cf 84 e4 7f 22 e3 e9 a4
0000c0 ab 04 12 e2 4d af 5d c3 21 7b 28 88 fb e7 d7 9f
0000d0 3d f5 26 6a 49 cf 1f 3f 98 9a 21 0d 46 83 2e bb
0000e0 7d 8e 83 49 80 a7 ee 88 f7 a2 89 92 7a 1d d9 98
0000f0 c8 e9 8c 29 d5 ca 68 57 84 e4 9d 16 ff d0 e7 7d
000100 ff af 72 4e e7 1c eb f0 c3 94 a2 8d 06 3f 00 d0
000110 bc fe 88 45 c3 3c 55 1a c0 6f 46 f9 98 cc 92 39
000120 41 4a 61 ac 25 94 4c 3f 4a bc c6 64 83 14 d2 7b

etc. No zeroes to be seen.

Had it just been the modified base64, it wouldn't have been a problem
to crack the format, but there's obviuosly more to this than that.


// Marcus