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:
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BIT MESSAGE FORMAT | |||||||||
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Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
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Octet-nth |
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HEADER |
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TYPE |
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YEAR | |
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MONTH | |
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DAY | |
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HOUR | |
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MINUTE | |
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SECOND | |
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TIMEZONE | |
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LENGTH | |
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CONTENT |
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Octet-1 |
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...
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...
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Octet-140 | |
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7-BIT PACKED MESSAGE | |||||||||
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Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
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Octet-nth |
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1 | 0 | b6 | b5 | b4 | b3 | b2 | b1 | b0 |
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8-BIT PACKED MESSAGE | |||||||||
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Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
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Octet-nth |
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1 | b7 | b6 | b5 | b4 | b3 | b2 | b1 | b0 |
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16-BIT PACKED MESSAGE | |||||||||
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Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
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Octet-nth |
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1 | b7 | b6 | b5 | b4 | b3 | b2 | b1 | b0 |
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2 | b15 | b14 | b13 | b12 | b11 | b10 | b9 | b8 |
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| HEADER | # OCTET | DESCRIPTION |
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| TYPE | 1 | contains specific flag for specific format identifier |
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DETAIL |
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Bit 0-1 : | reserved message class meaning |
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Bit 2-3 : | message encoding |
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Bit 3 | Bit 2 | Pack |
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0 | 0 | 7 bit |
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0 | 1 | 8 bit |
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1 | 0 | 16 bit |
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1 | 1 | reserved |
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Bit 4 : | reserved flag message class meaning |
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Bit 5 : | reserved message is compressed or uncompressed | |||||
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Bit 6-7 : | reserved general data coding |
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| TIMESTAMP | 7 | contains specific swapped nibbles for specific format identifier | |||||
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DETAIL |
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Octet 1 | YEAR e.g. 10 for 2001 |
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Octet 2 | MONTH e.g. 10 for Jan |
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Octet 3 | DAY e.g. 10 for 01 |
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Octet 4 | HOUR e.g. 10 for 01 |
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Octet 5 | MINUTE e.g. 10 for 01 |
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Octet 6 | SECOND e.g. 10 for 01 |
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Octet 7 | TIMEZONE e.g. 80 for 08 x 15 / 60 = +2 |
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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) | |||||
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| LENGTH | 1 | maximum characters allowed is 160, 140 or 70 characters depends on message packed format | |||||
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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:
CheckiO Extensions allow you to use local files to solve missions. More info in a blog post.
In order to install CheckiO client you'll need installed Python (version at least 3.8)
Install CheckiO Client first:
pip3 install checkio_client
Configure your tool
checkio --domain=py config --key=
Sync solutions into your local folder
checkio sync
(in beta testing) Launch local server so your browser can use it and sync solution between local file end extension on the fly. (doesn't work for safari)
checkio serv -d
Alternatevly, you can install Chrome extension or FF addon
checkio install-plugin
checkio install-plugin --ff
checkio install-plugin --chromium
Read more here about other functionality that the checkio client provides. Feel free to submit an issue in case of any difficulties.
