| poslední úprava: 9.3.2017 10:43
Portál AbcLinuxu, 25. dubna 2024 06:36
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| poslední úprava: 9.3.2017 10:43
Zajtra zdraží pivoObedové menu
Polievka 0,33 Hrachový krém s pažítkou
Hlavné jedlo 120/200 Pleskavica z teľacieho mäsa
dusená ryža, peperonáta a smotanový dressing
Ponuka ľahkých jedál 250 Miešaný zeleninový šalát,
grilované kuracie prsia, dressing 250 Mišaný zeleninový šalát,
grilované kúsky lososa, dressing 120/200 Grilovaný losos,
zemiaková kaša, restované fazuľkové kúsky, omáčka z lesných húb./snow -C -m "Zajtra zdraží pivo" -p "heslo" sprava.txt sprava.txt.snow ukrytie tajnej správy do textového súboru sprava.txt sprava.txt.snow je textový súbor s vloženou tajnou správou -C použije kompresiu -m text tajnej správy ktorú chceme vložiť -p použije heslo na zašifrovanie tajnej správy ./snow -C -p "heslo" sprava.txt.snow Zajtra zdraží pivo získanie ukrytej správy z textového súboru sprava.txt.snowBalíčky .deb - ak použijeme deb balíček program snow má meno stegsnow
man
snow [ -CQS ] [ -p passwd ] [ -l line-len ] [ -f file | -m message ] [ infile [ outfile ]]
Description
snow is a program for concealing messages in text files by
appending tabs and spaces on the end of lines, and for
extracting messages from files containing hidden
messages. Tabs and spaces are invisible to most text viewers hence the
steganographic nature of this encoding scheme.
The data is concealed in the text file by appending sequences of up to 7 spaces,
interspersed with tabs. This usually allows 3 bits to be stored every 8 columns. An
alternative encoding scheme, using alternating spaces and tabs to represent zeroes and ones,
was rejected because, although it used fewer bytes, it required
more columns per bit (4.5 vs 2.67).
The start of the data is indicated by an appended tab character, which allows the
insertion of mail and news headers without corrupting the data.
snow provides rudimentary compression, using Huffman tables optimised for English
text. However, if the data is not text, or if there is a lot of data, the use of the
built-in compression is not recommended, since an external compression
program such as compress or gzip will do a much better job.
Encryption is also provided, using the ICE encryption algorithm in 1-bit
cipher-feedback (CFB) mode. Because of ICE's arbitrary key size, passwords of any length
up to 1170 characters are supported (since only 7 bits of each character are used,
keys up to 1024-bytes are supported).
If a message string or message file are specified on the command-line, snow will
attempt to conceal the message in the file infile if specified, or standard input
otherwise. The resulting file will be written to outfile if specified, or
standard output if not.
If no message string is provided, snow attempts to extract a message from the input
file. The result is written to the output file or standard output.
Options
-C
Compress the data if concealing, or uncompress it if extracting.
-Q
Quiet mode. If not set, the program reports statistics such as compression
percentages and amount of available storage space used.
-S
Report on the approximate amount of space available for hidden message in the
text file. Line length is taken into account, but other options are ignored.
-p password
If this is set, the data will be encrypted with this password during concealment,
or decrypted during extraction.
-l line-length
When appending whitespace, snow will always produce lines shorter than this
value. By default it is set to 80.
-f message-file
The contents of this file will be concealed in the input text file.
-m message-string
The contents of this string will be concealed in the input text file. Note that,
unless a newline is somehow included in the string, a newline will not be
printed when the message is extracted.
Examples
The following command will conceal the message "I am lying" in the file infile, with
compression, and encrypted with the password "hello world". The resulting
text will be stored in outfile.
snow -C -m "I am lying" -p "hello world" infile outfile
To extract the message, the command would be
snow -C -p "hello world" outfile
Note that the resulting message will not be terminated by a newline.
To prevent line wrap if text with concealed whitespace is likely to be indented by
mail or news readers, a line length of 72 or less can be used.
snow -C -l 72 -m "I am lying" infile outfile
The approximate storage capacity of a file can be determined with the -S option.
snow -S -l 72 infile
Tiskni
Sdílej:
9.3.2017 00:23
Josef Kufner | skóre: 70
grilované kúsky lososati Slováci se vskutku zmáhají. Ještě před 30 lety taková zanedbaná země a dneska si dávají v restauraci lososa. Ale jinak díky za zajímavou informaci.
ISSN 1214-1267, (c) 1999-2007 Stickfish s.r.o.
