def embed_or_extract(algorithm, filename, destfilename, message, para, embed):
"""This function gets as parameters
filename ... the input file name
destfilename ... the output filen ame
message ... the message
para ... the parameter for the chosen algorithm
embed ... boolean: if True, we embed, else we extract.
If embed is True it uses libstego to embed the given message
in the given output file, calling the <algorithm>_embed()
function in libstego.
If embed is False, it uses libstego to extract a message
from the given file, calling the <algorithm>_extract()
function in libstego.
This function can therefor be called recursively to check
if embedding a message worked by calling it with embed=False.
"""
ending = filename[-3:]
print ending
if embed:
msglen = len(message) + 1
else:
message = libstego.new_charp()
msglen = libstego.new_intp()
if ending == "gif":
src_data = libstegofile.palette_data_t()
stego_data = libstegofile.palette_data_t()
gif_int = libstegofile.gif_internal_data_t()
libstegofile.io_gif_read(filename, src_data, gif_int)
if algorithm == "Sort / Unsort":
if embed:
libstego.sortunsort_embed(src_data, stego_data, message, msglen, para)
else:
libstego.sortunsort_extract(src_data, message, msglen, para)
elif algorithm == "GifShuffle":
if embed:
if para.method == 1:
pw_message = para.password
pw_message_len = para.pwlen
para.password = ""
para.pwlen = 0
pwmsg_data = libstegofile.palette_data_t()
para.method = 0
libstego.gifshuffle_embed(src_data, pwmsg_data, pw_message, pw_message_len, para)
para.method = 1
libstego.gifshuffle_embed(pwmsg_data, stego_data, message, msglen, para)
else:
print "normal gifshuffle:"
print "pw: " + para.password
print "pwlen: " + str(para.pwlen)
libstego.gifshuffle_embed(src_data, stego_data, message, msglen, para)
else:
if para.method == 1:
pw_message = para.password
pw_message_len = para.pwlen
para.password = ""
para.pwlen = 0
pwmsg_data = libstegofile.palette_data_t()
para.method = 0
libstego.gifshuffle_embed(src_data, pwmsg_data, pw_message, pw_message_len, para)
para.adv_pal = pwmsg_data
para.method = 1
libstego.gifshuffle_extract(src_data, message, msglen, para)
else:
libstego.gifshuffle_extract(src_data, message, msglen, para)
elif algorithm == "Frirui":
if embed:
libstego.frirui_embed(src_data, stego_data, message, msglen, para)
else:
libstego.frirui_extract(src_data, message, msglen, para)
if embed:
print "integrate and write ..."
libstegofile.io_gif_integrate(gif_int, stego_data)
libstegofile.io_gif_write(destfilename, gif_int)
# libstegofile.io_gif_cleanup_data(stego_data)
# libstegofile.io_gif_cleanup_data(src_data)
# libstegofile.io_gif_cleanup_internal(gif_int)
elif ending == "png":
src_data = libstegofile.rgb_data_t()
stego_data = libstegofile.rgb_data_t()
png_int = libstegofile.png_internal_data_t()
libstegofile.io_png_read(filename, src_data, png_int)
if algorithm == "Battlesteg":
if embed:
libstego.battlesteg_embed(src_data, stego_data, message, msglen, para)
else:
libstego.battlesteg_extract(src_data, message, msglen, para)
elif algorithm == "CPT":
if embed:
libstego.cpt_embed(src_data, stego_data, message, msglen, para)
else:
libstego.cpt_extract(src_data, message, msglen, para)
elif algorithm == "LSB":
bytes = libstego.new_charpp()
num_bytes = libstego.new_intp()
stego_data = src_data
libstego.lsb_convert_png(stego_data, bytes, num_bytes)
if embed:
ret = libstego.lsb_embed_indirect(
libstego.charpp_value(bytes), libstego.intp_value(num_bytes), message, msglen, para
)
if ret != 0:
print "An error occured. Error code: " + ` libstego.cvar.lstg_errno `
return False
else:
ret = libstego.lsb_extract_indirect(
libstego.charpp_value(bytes), libstego.intp_value(num_bytes), message, msglen, para
)
if ret != 0:
print "An error occured. Error code: " + ` libstego.cvar.lstg_errno `
return False
libstego.lsb_cleanup_converted_data(libstego.charpp_value(bytes))
libstego.delete_charpp(bytes)
if embed:
libstegofile.io_png_integrate(png_int, stego_data)
libstegofile.io_png_write(destfilename, png_int)
libstegofile.io_png_cleanup_data(stego_data)
# png cleanup ruft segmentation faults hervor...
# libstegofile.io_png_cleanup_data(src_data)
# libstegofile.io_png_cleanup_internal(png_int)
elif ending == "svg":
src_data = libstegofile.svg_data_t()
stego_data = libstegofile.svg_data_t()
svg_int = libstegofile.svg_internal_data_t()
libstegofile.io_svg_read(filename, src_data, svg_int)
if algorithm == "SVG Steg":
if embed:
ret = libstego.svg_embed(src_data, stego_data, message, msglen, para)
if ret != 0:
print "An error occured. Error code: " + ` libstego.cvar.lstg_errno `
return False
else:
ret = libstego.svg_extract(src_data, message, msglen, para)
if ret != 0:
print "An error occured. Error code: " + ` libstego.cvar.lstg_errno `
return False
if embed:
libstegofile.io_svg_integrate(svg_int, stego_data)
libstegofile.io_svg_write(destfilename, svg_int)
libstegofile.io_svg_cleanup_data(stego_data)
libstegofile.io_svg_cleanup_data(src_data)
libstegofile.io_svg_cleanup_internal(svg_int)
elif ending == "wav":
src_data = libstegofile.wav_data_t()
stego_data = libstegofile.wav_data_t()
wav_int = libstegofile.wav_internal_data_t()
libstegofile.io_wav_read(filename, src_data, svg_int)
if algorithm == "Echo Hiding":
if embed:
libstego.echohiding_embed(src_data, stego_data, message, msglen, para)
else:
libstego.echohiding_extract(src_data, message, msglen, para)
elif algorithm == "Phase Coding":
if embed:
libstego.phasecoding_embed(src_data, stego_data, message, msglen, para)
else:
libstego.phasecoding_extract(src_data, message, msglen, para)
libstegofile.io_wav_integrate(wav_int, stego_data)
libstegofile.io_wav_write(destfilename, wav_int)
libstegofile.io_wav_cleanup_data(stego_data)
libstegofile.io_wav_cleanup_data(src_data)
libstegofile.io_wav_cleanup_internal(wav_int)
elif ending == "jpg" or "peg":
src_data = libstegofile.jpeg_data_t()
stego_data = libstegofile.jpeg_data_t()
jpg_int = libstegofile.jpeg_internal_data_t()
libstegofile.io_jpeg_read(filename, src_data, jpg_int)
if algorithm == "F5":
if embed:
libstego.f5_embed(src_data, stego_data, message, msglen, para)
else:
libstego.f5_extract(src_data, message, msglen, para)
elif algorithm == "MB2":
if embed:
libstego.mb2_embed(src_data, stego_data, message, msglen, para)
else:
libstego.mb2_extract(src_data, message, msglen, para)
libstegofile.io_jpeg_integrate(jpg_int, stego_data)
libstegofile.io_jpeg_write(destfilename, jpg_int)
# libstegofile.io_jpeg_cleanup_data(stego_data)
libstegofile.io_jpeg_cleanup_data(src_data)
libstegofile.io_jpeg_cleanup_internal(jpg_int)
# TODO: extract for testing purpose!
if embed:
return True
else:
new_message = str(libstego.charp_value(message))
length = libstego.intp_value(msglen)
print new_message
return new_message
def get_best_method(filename, msglen):
global num_methods
global method_to_algo
global methods
for method in range(0, num_methods):
fits = False
para = methods[method]
print "Testing method " + `method+1`
print "Algorithm: " + method_to_algo[method]
if method_to_algo[method] == "PQ":
# prepare data strucures
jpeg_data = libstegofile.jpeg_data_t()
jpeg_int = libstegofile.jpeg_internal_data_t()
# read file data
err = libstegofile.io_jpeg_read(filename, jpeg_data, jpeg_int)
if err != 0:
# TODO better error handling -> detailed message what went wrong
# by using the 'lstg_errno' code
return None
# check if message fits with the current params
if libstego.pq_check_capacity(jpeg_data, para) >= msglen:
fits = True
# cleanup
libstegofile.io_jpeg_cleanup_data(jpeg_data)
libstegofile.io_jpeg_cleanup_internal_data(jpeg_int)
elif method_to_algo[method] == "F5":
# prepare data strucures
jpeg_data = libstegofile.jpeg_data_t()
jpeg_int = libstegofile.jpeg_internal_data_t()
# read file data
err = libstegofile.io_jpeg_read(filename, jpeg_data, jpeg_int)
if err != 0:
# TODO better error handling -> detailed message what went wrong
# by using the 'lstg_errno' code
return None
# check if message fits with the current params
if libstego.f5_check_capacity(jpeg_data) >= msglen:
fits = True
# cleanup
libstegofile.io_jpeg_cleanup_data(jpeg_data)
libstegofile.io_jpeg_cleanup_internal_data(jpeg_int)
elif method_to_algo[method] in ["Adv. Gifshuffle", "Gifshuffle"]:
# prepare data strucures
palette_data = libstegofile.palette_data_t()
gif_int = libstegofile.gif_internal_data_t()
# read file data
err = libstegofile.io_gif_read(filename, palette_data, gif_int)
if err != 0:
# TODO better error handling -> detailed message what went wrong
# by using the 'lstg_errno' code
return None
# check if message fits with the current params
if libstego.gifshuffle_check_capacity(palette_data, para) >= msglen:
fits = True
# cleanup
libstegofile.io_gif_cleanup_data(palette_data)
libstegofile.io_gif_cleanup_internal(gif_int)
elif method_to_algo[method] == "Frirui":
# prepare data strucures
palette_data = libstegofile.palette_data_t()
gif_int = libstegofile.gif_internal_data_t()
# read file data
err = libstegofile.io_gif_read(filename, palette_data, gif_int)
if err != 0:
# TODO better error handling -> detailed message what went wrong
# by using the 'lstg_errno' code
return None
# check if message fits with the current params
if libstego.frirui_check_capacity(palette_data, para) >= msglen:
fits = True
# cleanup
libstegofile.io_gif_cleanup_data(palette_data)
libstegofile.io_gif_cleanup_internal(gif_int)
elif method_to_algo[method] == "Sort/Unsort":
# prepare data strucures
palette_data = libstegofile.palette_data_t()
gif_int = libstegofile.gif_internal_data_t()
# read file data
err = libstegofile.io_gif_read(filename, palette_data, gif_int)
if err != 0:
# TODO better error handling -> detailed message what went wrong
# by using the 'lstg_errno' code
return None
# check if message fits with the current params
if libstego.sortunsort_check_capacity(palette_data, para) >= msglen:
fits = True
# cleanup
libstegofile.io_gif_cleanup_data(palette_data)
libstegofile.io_gif_cleanup_internal(gif_int)
elif method_to_algo[method] == "CPT":
# prepare data strucures
rgb_data = libstegofile.rgb_data_t()
png_int = libstegofile.png_internal_data_t()
# read file data
err = libstegofile.io_png_read(filename, rgb_data, png_int)
if err != 0:
# TODO better error handling -> detailed message what went wrong
# by using the 'lstg_errno' code
return None
# check if message fits with the current params
if libstego.cpt_check_capacity(rgb_data, para) >= msglen:
fits = True
# cleanup
libstegofile.io_png_cleanup_data(rgb_data)
libstegofile.io_png_cleanup_internal(png_int)
elif method_to_algo[method] == "Battlesteg":
# prepare data strucures
rgb_data = libstegofile.rgb_data_t()
png_int = libstegofile.png_internal_data_t()
# read file data
err = libstegofile.io_png_read(filename, rgb_data, png_int)
if err != 0:
# TODO better error handling -> detailed message what went wrong
# by using the 'lstg_errno' code
return None
# check if message fits with the current params
if libstego.battlesteg_check_capacity(rgb_data, para) >= msglen:
fits = True
# cleanup
libstegofile.io_png_cleanup_data(rgb_data)
libstegofile.io_png_cleanup_internal(png_int)
elif method_to_algo[method] == "SVG Steg":
# prepare data strucures
svg_data = libstegofile.svg_data_t()
svg_int = libstegofile.svg_internal_data_t()
# read file data
err = libstegofile.io_svg_read(filename, svg_data, svg_int)
if err != 0:
# TODO better error handling -> detailed message what went wrong
# by using the 'lstg_errno' code
return None
# check if message fits with the current params
if libstego.svg_check_capacity(svg_data, para) >= msglen:
fits = True
# cleanup
libstegofile.io_svg_cleanup_data(svg_data)
libstegofile.io_svg_cleanup_internal(svg_int)
elif method_to_algo[method] == "Echo Hiding":
# prepare data strucures
wav_data = libstegofile.wav_data_t()
wav_int = libstegofile.wav_internal_data_t()
# read file data
err = libstegofile.io_wav_read(filename, wav_data, wav_int)
if err != 0:
# TODO better error handling -> detailed message what went wrong
# by using the 'lstg_errno' code
return None
# check if message fits with the current params
if libstego.eh_check_capacity(wav_data, para) >= msglen:
fits = True
# cleanup
libstegofile.io_wav_cleanup_data(wav_data)
libstegofile.io_wav_cleanup_internal(wav_int)
elif method_to_algo[method] == "Phase Coding":
# TODO implement
pass
elif method_to_algo[method] == "LSB":
# TODO implement
pass
if fits:
print "best method: " + `method+1`
return method
return None