UNIX for Advanced & Expert Users

I have extracted a raw data file from a magnetic tape using the dd command

Afterwards, I managed to read the extracted data with Bless HexEditor and I found out that at offset 0x200000 there is a sequence of value which originally was stored in a table.

I would like to extract this data and import it in an Excel or CSV file, but above all I would like to understand the data encryption.

This is an example of the data extracted in hexadecimal format and its representation in unsigned int little endian:

Code:

//Hex Not.    // Little-Endian unsigned int 32
10 00 00 00   // 84       (Ref Number)  
55 F1 2E 04   // 20070306 (Date)
A2 3F 32 01   // 15144184 (Time)
F8 14 E7 00   // 20070306 (Date)
A2 3F 32 01   // 15491037 (Time)
DD 5F EC 00   // 1
01 00 00 00   // 1
01 00 00 00   // 4486656
00 76 44 00   // 492
EC 01 00 00   // 1
01 00 00 00   // 814185724
FC 7C 87 30   // 814185728
00 7D 87 30   // 814185732
04 7D 87 30   // 16

New Line

10 00 00 00   // 84
55 F1 2E 04   // 20070306
A2 3F 32 01   // 15491037
DD 5F EC 00   // 20070306
A2 3F 32 01   // 15534889
29 0B ED 00   // 18
12 00 00 00   // 1
01 00 00 00   // 4486656
00 76 44 00   // 492
EC 01 00 00   // 1
01 00 00 00   // 814185724
FC 7C 87 30   // 814185728
00 7D 87 30   // 814185732
04 7D 87 30   // 16

Can you understand starting from this piece of converted data how the raw file is encoded and how I can create a bash script to decode it??

Thanks

Moderator's Comments:

Please use code tags next time for your code and data. Thanks

Try the file command. It might give you some info about the file.

Do you suggest any particular parameter?

It returns that that file is a normal data stream (Very Useful )
The magic file cannot be found and the data is in a proprietary format.

Before we can help more: What is the source of the tape?

Please: Give the name of the OS or brand of machine that wrote it - the OS or brand of computer, not the tape drive name.

There are some ways to "resurrect" tape data from ancient systems.

The hardware configuration should be:
CPU Pentium II 400 MHz
Internal memory 128 Mb

Operating System: Windows 2000 server

If the data is in a proprietary format, you pretty much have to go back to the proprietor of that format.

You might get something useful by running "strings" against the file.

Thank you for your reply

I have heard many times that this job cannot be done without knowing the source of my data and how it has been written on the tape and I agree with you. Unfortunately, I must do it without any insight and this is the reason why I started looking at its hexadecimal notation with an hex editor.

The tape is a mix of metadata and voice audio and I need to figure out how I can decrypt both these source within the image.

Thanks to the hex editor I now understand that before each audio there is a piece information concerning the audio.

The information above is regarding this info.
My knowledge about reverse engineering is limited but I must do it (Job is Job )

Apprarently I was previously wrong since I have copied and pasted this piece of data on this website and the data format seems to be big endian 32

Btw I have typed this command in the shell to convert the file

Code:

cat file | strings --encoding=B > convToString

but something went wrong.

whereas the command

Code:

cat file | strings > convToString

convert it but with many errors

Any help?