This is a breakdown of the most common uses of Snow, a Steganography tool.
Compress the data if concealing, or uncompress it if extracting.
Quiet mode. If not set, the program reports statistics such as compression percentages and amount of available storage space used.
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.
If this is set, the data will be encrypted with this password during concealment, or decrypted during extraction.
When appending whitespace, snow will always produce lines shorter than this value. By default it is set to 80.
The contents of this file will be concealed in the input text file.
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.
Synopsis: snow [ -CQS ] [ -p passwd ] [ -l line-len ] [ -f file | -m message ] [ infile [ outfile ]]
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
Note that the resulting message will not be terminated by a newline.
snow -C -p "hello world" outfile
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
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
Note for Compression: 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.