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_capacity(algorithm, filename, para):
"""This function gets parameters
algorithm ... the String naming the chosen algorithm
filename ... the chosen input filename
para ... a parameter for the chosen algorithm
and computes the capacity of the algorithm for the
given file and parameters.
It returns the capacity.
"""
if filename[-3:] == "gif":
palette_data = libstegofile.palette_data_t()
gif_struct = libstegofile.gif_internal_data_t()
bla = libstegofile.io_gif_read(filename, palette_data, gif_struct)
if algorithm == "Frirui":
cap = libstego.frirui_check_capacity(palette_data, para)
elif algorithm == "GifShuffle":
cap = libstego.gifshuffle_check_capacity(palette_data, para)
elif algorithm == "Sort / Unsort":
cap = libstego.sortunsort_check_capacity(palette_data, para)
libstegofile.io_gif_cleanup_data(palette_data)
# libstegofile.io_gif_cleanup_internal(gif_struct)
elif filename[-3:] == "png":
rgb_data = libstegofile.rgb_data_t()
rgb_internal = libstegofile.png_internal_data_t()
bla = libstegofile.io_png_read(filename, rgb_data, rgb_internal)
if algorithm == "Battlesteg":
cap = libstego.battlesteg_check_capacity(rgb_data, para)
elif algorithm == "CPT":
cap = libstego.cpt_check_capacity(rgb_data, para)
elif algorithm == "LSB":
bytes = libstego.new_charpp()
num_bytes = libstego.new_intp()
libstego.lsb_convert_png(rgb_data, bytes, num_bytes)
cap = libstego.lsb_check_capacity_indirect(
libstego.charpp_value(bytes), libstego.intp_value(num_bytes), para
)
libstego.lsb_cleanup_converted_data(libstego.charpp_value(bytes))
libstego.delete_charpp(bytes)
elif filename[-3:] == "wav":
wav_data = wav_data_t()
wav_int = wav_internal_data_t()
bla = libstegofile.io_wav_read(filename, wav_data, wav_int)
if algorithm == "Echo Hiding":
cap = libstego.echohiding_check_capacity(wav_data, para)
elif algorithm == "Phase Coding":
cap = libstego.phasecoding_check_capacity(wav_data, para)
elif algorithm == "PW":
cap = libstego.pw_check_capacity(wav_data, para)
elif filename[-3:] == "svg":
svg_data = libstegofile.svg_data_t()
svg_int = libstegofile.svg_internal_data_t()
bla = libstegofile.io_svg_read(filename, svg_data, svg_int)
if algorithm == "SVG Steg":
cap = libstego.svg_check_capacity(svg_data, para)
elif filename[-3:] in ["peg", "jpg"]:
jpeg_data = libstegofile.jpeg_data_t()
jpeg_int = libstegofile.jpeg_internal_data_t()
bla = libstegofile.io_jpeg_read(filename, jpeg_data, jpeg_int)
if algorithm == "F5":
cap = libstego.f5_check_capacity(jpeg_data, para)
elif algorithm == "MB2":
cap = libstego.mb2_check_capacity(jpeg_data, para)
elif algorithm == "PQ":
cap = libstego.pq_check_capacity(jpeg_data, para)
elif algorithm == "LSB":
cap = libstego.lsb_check_capacity(palette_data, para)
print cap
if cap[0] == 0:
return cap[1]
else:
print "Error computing capacity!"
return 666