Bit Message
The Bit Message is a message that is hidden within the lines of an octet stream and it is represented as a hexadecimal string which has maximum length of 149 octets. The first 9 octets of the message contain the header for the message and the rest comprise the content . The header contains 1 type octet, 7 timestamp octets, and 1 message length octet. The content contains a maximum of 140 octets and could be packed with either 7 bit, 8 bit or 16 bit. 7 bit packed messages have a length of 160 characters, 8 bit packed messages have a length of 140 characters, and 16 bit packed messages will only have a length of 70 characters.
Here are some details on the structure of a bit message:
|
|
BIT MESSAGE FORMAT | |||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|
|
|
Octet-nth |
|
|
|
|
|
|
|
|
|
|
|
HEADER |
|
|
|
|
|
|
|
|
TYPE |
|
|
|
|
|
|
|
|
|
|
YEAR | |
|
|
|
|
|
|
|
|
|
|
MONTH | |
|
|
|
|
|
|
|
|
|
|
DAY | |
|
|
|
|
|
|
|
|
|
|
HOUR | |
|
|
|
|
|
|
|
|
|
|
MINUTE | |
|
|
|
|
|
|
|
|
|
|
SECOND | |
|
|
|
|
|
|
|
|
|
|
TIMEZONE | |
|
|
|
|
|
|
|
|
|
|
LENGTH | |
|
|
CONTENT |
|
|
|
|
|
|
|
|
Octet-1 |
|
|
...
|
|
|
|
|
|
|
|
...
|
|
|
|
|
|
|
|
|
|
|
|
Octet-140 | |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
7-BIT PACKED MESSAGE | |||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|
|
|
Octet-nth |
|
|
|
|
|
|
|
|
|
|
|
1 | 0 | b6 | b5 | b4 | b3 | b2 | b1 | b0 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
8-BIT PACKED MESSAGE | |||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|
|
|
Octet-nth |
|
|
|
|
|
|
|
|
|
|
|
1 | b7 | b6 | b5 | b4 | b3 | b2 | b1 | b0 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
16-BIT PACKED MESSAGE | |||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
|
|
|
Octet-nth |
|
|
|
|
|
|
|
|
|
|
|
1 | b7 | b6 | b5 | b4 | b3 | b2 | b1 | b0 |
|
|
|
2 | b15 | b14 | b13 | b12 | b11 | b10 | b9 | b8 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| HEADER | # OCTET | DESCRIPTION |
|
||||
|
|
|
|
|
|
|
|
|
| TYPE | 1 | contains specific flag for specific format identifier |
|
||||
|
|
|
|
|
|
|
|
|
|
|
DETAIL |
|
|
|
|
|
|
|
|
Bit 0-1 : | reserved message class meaning |
|
||||
|
|
Bit 2-3 : | message encoding |
|
||||
|
|
|
Bit 3 | Bit 2 | Pack |
|
|
|
|
|
|
0 | 0 | 7 bit |
|
|
|
|
|
|
0 | 1 | 8 bit |
|
|
|
|
|
|
1 | 0 | 16 bit |
|
|
|
|
|
|
1 | 1 | reserved |
|
|
|
|
|
|
|
|
|
|
||
|
|
Bit 4 : | reserved flag message class meaning |
|
||||
|
|
Bit 5 : | reserved message is compressed or uncompressed | |||||
|
|
Bit 6-7 : | reserved general data coding |
|
||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| TIMESTAMP | 7 | contains specific swapped nibbles for specific format identifier | |||||
|
|
|
|
|
|
|
||
|
|
DETAIL |
|
|
|
|
|
|
|
|
Octet 1 | YEAR e.g. 10 for 2001 |
|
||||
|
|
Octet 2 | MONTH e.g. 10 for Jan |
|
||||
|
|
Octet 3 | DAY e.g. 10 for 01 |
|
||||
|
|
|
|
|
|
|
|
|
|
|
Octet 4 | HOUR e.g. 10 for 01 |
|
||||
|
|
Octet 5 | MINUTE e.g. 10 for 01 |
|
||||
|
|
Octet 6 | SECOND e.g. 10 for 01 |
|
||||
|
|
|
|
|
|
|
|
|
|
|
Octet 7 | TIMEZONE e.g. 80 for 08 x 15 / 60 = +2 |
|
||||
|
|
|
The Time Zone is GMT format, expressed in quarters of an hour. In the first of the two semi-octets, the first bit represents the algebraic sign of this difference (0 : positive, 1 : negative) | |||||
|
|
|
||||||
|
|
|
||||||
|
|
|
||||||
|
|
|
|
|||||
|
|
|
|
|
|
|
|
|
| LENGTH | 1 | maximum characters allowed is 160, 140 or 70 characters depends on message packed format | |||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Input data: A hexadecimal string that is a bit message (unicode).
Output data: A list containing the timestamp, length of message and the message itself. The message is unicode.
Example:
assert(checkio('002080629173148007EDF27C1E3E9701') ==
['26 Aug 2002 19:37:41 GMT +2', 7, 'message']), "First Test"
assert(checkio('00317050201171820FD3323BDC0ED341C4303DEC3E8700') ==
['05 Jul 2013 02:11:17 GMT +7', 15, u'Selamat Datang!']), "Second Test, 7 bit"
assert(checkio('000130925161956915C8729E054A82C26D50DA0D7296EFA0EC5BBE06') ==
['29 Mar 2010 15:16:59 GMT -4', 21, 'Hey, I am in New York']), "Third Test, negative timezone"
assert(checkio('08071010101010611F04180441043A043B044E04470435043D043804350020043F043E04340442043204350440043604340430043504420020043F0440043004320438043B043E') ==
['01 Jan 1970 01:01:01 GMT +4', 31, 'Исключение подтверждает правило']), "Fourth Test, simulate 32-bit signed integer real life problem"
assert(checkio('088310913041804C23805E4E0D82E5805E4E4B002C805E4E4B4E0D82E5898B4E4B002C898B4E4B4E0D82E577E54E4B002C77E54E4B4E0D82E5884C4E4B002C5B7881F365BC884C4E4B800C6B6277E3 ') ==
['19 Jan 2038 03:14:08 GMT -11', 35, '聞不若聞之,聞之不若見之,見之不若知之,知之不若行之,學至於行之而止矣']), "But, we pass Y2K38 problem"
How it is used:
