| mity@ropnet.ru 6 July 2001(lst modyfied 01/10/01 |
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Audio Galaxy Satellite Communication
Protocol
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Introduction.
AGSatelite.exe - this is client, it is a file sharing program, based on p2p.
This document, shows the way AGSatelite.exe communicates with server, and it describes the structure of messages, between 2 clients. And it gives a set of messages used. This document is an instruction, for public use. It can be enriched by any one who has an information related to the topic of this document. If you found any faults or you wish to add any thing just mail me. The following information was received by analyzing the traffic from AGSatelite.exe( W606)
Rules, Procedures.
AGSatelite(further Client) uses TCP for data transmission. The connection to servers is made through port 21. For connecting client uses 2 servers.
Connecting to the information service of audiogalaxy.com
1) Client makes connection to the Master Server(squash.audiogalaxy.com).
2) Client receives a REDIRECTION message.
3) Client connects to the information server(further Server).
(the following 3 steps where decrypted by thenks to Justin
Fletcher all thenxs goes to him)
4) Server sends Hash prefix (55)
5) Client generates 16 byte MD5
hash for the string PREFIX+PASSWORD. For example if you received a prefix
'fgh4564t' ajnd your password is 'teapot' you need to hash the string 'fgh4564tteapot'.
MD5 hashing will give you 16 byte string. Then you put it in the end of LOGIN
msg.
4) Client sends LOGIN(0) message.
5) Server tests the abilities of the client to Listen, and to Connect(further
proxy test)
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Proxy test. The server sends FILE TRANSFER(10) message which makes client download 'proxy test' file. Connection is made with client-client protocol. After connecting to server or opening port, client sends message FILE TRANSFER STATUS(6) with status 3. After client sends FILE REQUEST message, server closes the connection without sending any data(It is a step of connection checking).After connection is closed client sends FILE TRANSFER STATUS(6) with status 5. There are 3 tests. 2 - test for an ability to Listen, 1 - test for ability to Connect. |
6) Client informs server of the files to be shared.
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Informing Server of the Shares. The server sends message 8 a few times. On which you reply with message 7. Then server sends SEND SHARES(9) message. This message shows that you can send your shares. If you have any new files(which don't have server id) in the data base you send it's info with the message 33, then the server will reply with message 13 with the server IDs for the file. To inform the server about the files which alrady have server id, thet they are online, you send message 32. If you don't have any files to share you reply with message 7, but if so you will not be able to download more then 1 file at a time. |
7) Every 30 seconds you send message 5.
Files sharing
After going through LOGIN process, client may receive FILE TRANSFER(10) message - it is an information from the server to start file sharing. It may inform you to upload or download file. It also gives you information weather to Listen or Connect.
If client must wait for connection:
1) Client opens a port defined in the message 10. The IP set in the message is just a mask, it shows only first 2 bytes.
2) Client sends message 6 status 3
If client must connect.
1) Client makes a connection to the IP and port defined in message 10
2) Client sends message 6 status 3
If client downloads.
1) After connection is done Client sends FILE REQUEST message which consists of FILE ID received from message 10. Size of the file to be downloaded, and the position to resume(the first byte of the file is at position 0)
2) The sender if the file was found sends RESPONSE FOR REQUEST in response. After finishing both sides send message 6 status 0. And the downloader sends message 33 with the information on new file.
Transfer shutdown
During file transfer server may send message 11 with the FILE ID of the transfer to be shutted down. After the p2p connection was closed client sends message 6 status 8.
Message specification.
The messages in this protocol have binary structure. It is base on the fields of 4 types:
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String
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string size
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2 bytes (size of char array) |
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char array
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Byte
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1 byte (first byte is on the right) |
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Word
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2 byte (first byte is on the right) |
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Integer
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4 byte (first byte is on the right) |
Messages may be of 2 types:
1) Messages used fore redirection and clien-client
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START SIGNAL
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1163907285 (4 bytes) | |
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MESSAGE SIZE
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4 bytes . | A Size of the whole message without START SIGNAL |
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ID
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4 bytes | message count |
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Then fields specific for every message
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1) Messages server-client
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START SIGNAL
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17759(2 bytes) | |
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MESSAGE SIZE
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2 bytes . | A Size of the whole message without START SIGNAL |
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MESSAGE TYPE
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1 bytes | |
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Then fields specific for every message
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Message declaration.
REDIRECTOR (use the first type of header)
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REDIRECTION
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PORT - 4 bytes
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SERVER IP- String
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PEER TO SERVER (use the second type of header)
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msg ID
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parametrs
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comments
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LOGIN
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0
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? - 4 bytes | just use 0 |
| LOGIN - string | ||
| ZERO - String(2 byte) | just use 0 | |
| SATELITE VERSION - string | ||
| CLIENT IP - string | ||
| CLIENT HOST_NAME - string | ||
| ?(0) - 4 bytes | just use 0 | |
| 16 BYTE HASH | see Rules, Procedures. |
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LOGOFF
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1
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Sent when you quit the satelite |
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READY FOR TRANSFER
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5
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is sent every 20-40 sec, to keep you connected | |||
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FILE TRANSFER STATE
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6
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FILE_ID - string | ||||||||
STATE - 4 bytes
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READY TO SEND SHAES
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7
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it is sent in reply for message '8' and message '9' | |||
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SEND SHARES STEND BY
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8
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it is sent after proxy test is done, i guess it is a command for client to start gathering shares to send to the server | |||
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SEND SHARES
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9
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you send shares, and reply with '7', | |||
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FILE TRANSFER
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10
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FILE_ID - string | ||||
CONNECT - 1 byte
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DIRRECTION - 1 byte
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| IP - string | |||||
| PORT - 4 bytes | |||||
| ? - 4 bytes | |||||
| FILE NAME - string | |||||
| FILE SIZE - 4 byes |
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STOP FILE TRANSFER
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11
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FILE_ID - string | |
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NEW SHARE RESPONSE
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13
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Local ID - 4 bytes | position in the db file |
| fileSet - string | server position | |
| fileID - 4 bytes | server position | |
| songID - 4 bytes | server position | |
| size - 4 bytes | ||
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WRONG LOGIN MESSAGE
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14
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ERROR TYPE - 4 byte
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( msg was reseive from email of Marc Warne, addjusted from the msg of Justin Fletcher) | ||||||
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EX ACCOUNT INFORMATION
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31
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SATELITE_VERSION - string | |
| LOGIN - string | ||
| PASSWORD - string | ||
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OLD SHARES
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32
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Local ID - 4 bytes | |
| fileSet - string | ||
| fileID - 4 bytes | ||
| songID - 4 bytes | ||
| size - 4 bytes | ||
| bitRate - 4 bytes | ||
| LAST MOD DATE- 4 byte | ||
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DATA TO UPDATE SHARES
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33
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? - 4 byte | always was 0 | |||
| DB FILE COUNT- 2 byte | |||||
| FILE NAME- string | |||||
| FOLDER - string | |||||
| FILE SIZE - 4 byte | |||||
| KB/S - 2 byte | |||||
| SEC LENGTH- 4 byte | |||||
| LAST MOD DATE- 4 byte | |||||
FLAG ID3v1 exists - 1 byte
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If you set 0 then you don't need to add all the following( untill flag ID3v2) fields | ||||
| TITLE - string | lower register | ||||
| ARTIST - string | lower register | ||||
| ALBUM - string | lower register | ||||
FLAG ID3v2 exists - 1 byte
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If you set 0 then you don't need to add all the following fields | ||||
| TITLE - string | |||||
| ARTIST - string | |||||
| ALBUM - string | |||||
| TRACK - 2 byte | |||||
| ? - 2 bytes | it is not any field of the tag. May be just some reserved field, it is always 0 |
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NEW ACCOUNT INFORMATION
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35
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SATELITE_VERSION - string | |
| LOGIN - string | ||
| PASSWORD - string | ||
| E-MAIL - string | ||
| AGE - string | ||
| SEX - string | ||
| CITY - string | ||
| STATE - string | ||
| ZIP - string | ||
| COUNTRY - string | ||
| HOW_HEARD - string | ||
| ?(0) - 4 bytes |
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NEW ACCOUNT INFORMATION RESPONSE
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50
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RESPONSE - 4 bytes | ||||||||
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Thenks to efoster | ||||||||
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EX ACCOUNT INFORMATION RESPONSE
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51
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RESPONSE - 4 bytes | ||||
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DB UPDATE WITH FILE ID
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52
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File ID - string | |
| File Name - string | ||
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PLAY A FILE IN LOCAL DB
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53
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Unknown - 4 byte (allways 1) | thenks to Justin Fletcher |
| Unknown - 4 byte (allways 1) | ||
| Local ID - 4 bytes file id in db ( set by msg32) | ||
| Unknown - 4 byte | ||
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LOGIN HASH PREFIX
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55
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prefix - String | thenks to Justin Fletcher |
PEER TO PEER (use the first type of header)
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FILE REQUEST
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FILE ID - string
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FILE SIZE- 4 bytes
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RESUME POSITION- 4 bytes
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RESPONSE FOR REQUEST
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FILE ID - string
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FILE SIZE- 4 bytes
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"OK" - string
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7. Acknowledgements
A big THANKS goes to NAI for a very good Sniffer.
And to More Beer for some tips with AG emulator.