Using OpenStego from Command-line

The general syntax for OpenStego is:

java -jar <path>\openstego.jar <command> [options]

Here, the first argument must be a command. Valid commands are:

Command	Action
embed, --embed	Embed message into cover file
extract, --extract	Extract message from stego file
gensig, --gensig	Generate a signature for watermarking
embedmark, --embedmark	Watermark a cover file using signature
checkmark, --checkmark	Checks for watermark presence in the file
algorithms, --algorithms	List down supported steganography algorithms
readformats, --readformats	List down supported formats for cover file
writeformats, --writeformats	List down supported formats for stego file
help, --help	Display the help. To get help on options specific to an algorithm, provide the name of the algorithm using -a option

Following option is common for all commands other than algorithms

Option	Description
-a, --algorithm <algorithm_name>	Name of the steganography algorithm to use. List of the supported algorithms can be retrieved using algorithms command

Possible options for embed command

Option	Description
-mf, --messagefile <filename>	Source message/data file. If this option is not provided or - is provided as the value then the message data is read from stdin
-cf, --coverfile <filename>	Cover file in which the message will be embedded. This option supports * and ? wildcards for filename. If wildcard filename is provided then make sure that it is surrounded by double quotes. Multiple filenames can also be provided by separating them with ; (semi-colon). If the wildcard expression returns more than one file, then -sf option is ignored, and each coverfile is overwritten with the corresponding generated stegofile
-sf, --stegofile <filename>	Output stego file containing the embedded message. If this option is not provided or - is provided as the value then the stego file is written to stdout
-c, --compress	Compress the message file before embedding (default)
-C, --nocompress	Do not compress the message file before embedding
-e, --encrypt	Encrypt the message file before embedding
-E, --noencrypt	Do not encrypt the message file before embedding (default)
-p, --password <password>	Password to be used for encryption. If this is not provided then prompt will be displayed for entry
-A, --cryptalgo <crypto algorithm>	Algorithm to be used for encryption. Defaults to AES128. Possible values are AES128 or AES256. Please note that AES256 will only be supported with JRE having unlimited strength jurisdiction policy

Additions and changes to embed options while using RandomLSB Plugin

Option	Description
-b, --maxBitsUsedPerChannel <n>	Max number of bits to use per color channel in the image for embedding data. This value can be increased at the expense of image quality, in case size of image is not able to accommodate the data (Default = 3)
-cf, --coverfile <filename>	If this option is not provided or - is provided as the value then a random image containing noise is generated and used as cover file. The size of image is minimum required to embed the given source file when maxBitsUsedPerChannel bits are used per color channel
-sf, --stegofile <filename>	If this option is not provided or - is provided as the value then stego file is written to stdout in PNG format

Possible options for extract command

Option	Description
-sf, --stegofile <filename>	Stego file containing the embedded message
-xf, --extractfile <filename>	Optional filename for the extracted data. Use this to override the filename embedded in the stego file
-xd, --extractdir <dir>	Directory where the message file will be extracted. If this option is not provided, then the file is extracted to current directory
-p, --password <password>	Password to be used for decryption. If this is not provided then prompt will be displayed for entry (if the message is encrypted)

Possible options for gensig command

Option	Description
-gf, --sigfile <filename>	Output signature file that can be used to watermark files. If this option is not provided or - is provided as the value then the signature file is written to stdout
-p, --password <password>	Password to be used for generation of signature. If this is not provided then prompt will be displayed for entry

Possible options for embedmark command

Option	Description
-gf, --sigfile <filename>	Watermarking signature file. If this option is not provided or - is provided as the value then the signature data is read from stdin
-cf, --coverfile <filename>	Cover file which needs to be digitally watermarked. This option supports * and ? wildcards for filename. If wildcard filename is provided then make sure that it is surrounded by double quotes. Multiple filenames can also be provided by separating them with ; (semi-colon). If the wildcard expression returns more than one file, then -sf option is ignored, and each coverfile is overwritten with the corresponding generated stegofile
-sf, --stegofile <filename>	Output stego file containing the embedded watermark. If this option is not provided or - is provided as the value then the stego file is written to stdout

Possible options for checkmark command

Option	Description
-sf, --stegofile <filename>	Stego file containing the embedded watermark
-gf, --sigfile <filename>	Signature file which was used to watermark the file

Examples

To embed secret.txt into wallpaper.png and generate the output into test.png:

java -jar <path>\openstego.jar embed -a randomlsb -mf secret.txt -cf wallpaper.png -sf test.png

OR

java -jar <path>\openstego.jar --embed --algorithm=randomlsb --messagefile=secret.txt --coverfile=wallpaper.png --stegofile=test.png

To extract embedded data from test.png to /data directory:

java -jar <path>\openstego.jar extract -a randomlsb -sf test.png -xd /data

OR

java -jar <path>\openstego.jar extract --algorithm=randomlsb --stegofile=test.png --extractdir=/data

To generate a signature file:

java -jar <path>\openstego.jar gensig -a dwtdugad -gf my.sig

OR

java -jar <path>\openstego.jar --gensig --algorithm=dwtdugad --sigfile=my.sig

To embed signature into owned.png and generate the output into out.png:

java -jar <path>\openstego.jar embedmark -a dwtdugad -gf my.sig -cf owned.png -sf out.png

OR

java -jar <path>\openstego.jar --embedmark --algorithm=dwtdugad --sigfile=my.sig --coverfile=owned.png --stegofile=out.png

To check for watermark in test.png using my.sig signature file:

java -jar <path>\openstego.jar checkmark -a dwtdugad -gf my.sig -sf test.png

OR

java -jar <path>\openstego.jar checkmark --algorithm=dwtdugad --sigfile=my.sig --stegofile=test.png

Piping example:

ls -R | java -jar <path>\openstego.jar embed -a randomlsb > test.png

Wildcard example (Please note that the double quotes are important):

java -jar <path>\openstego.jar embed -a randomlsb -cf "img???.png;wall*.png" -mf watermark.txt