harlo / f5android

library porting 5f-steganography library to android.

F5Android

library porting 5f-steganography library to android.

see https://code.google.com/p/f5-steganography/

f5android's Issues

System.loadLibrary("f5buffers")

java.lang.UnsatisfiedLinkError: dalvik.system.PathClassLoader[DexPathList[[zip file "/data/app/com.example.vipin.myfirstapp-2/base.apk"],nativeLibraryDirectories=[/data/app/com.example.vipin.myfirstapp-2/lib/arm64, /system/fake-libs64, /data/app/com.example.vipin.myfirstapp-2/base.apk!/lib/arm64-v8a, /system/lib64, /vendor/lib64]]] couldn't find "libF5Buffers.so"

remove automatic "_embed.jpg" naming tag to obscure stego

images that are run through f5 stego should not all be tagged with the same "_embed" appendix. we should keep the image files as close to a standard/normail alphanum sequence as possible.

Fix output filename tagging with "_embed.jpg" taking 1 char from original name

Right now if no output filename is provided, F5Android library defaults to replacing the original extension by "_embed.jpg" but while doing so, it also messes up last char of original name. Example:
IMG_0001.jpg becomes IMG_000_embed.jpg (last 1 is accidentally chopped)

Fix:
Please change line 60 of Embed.java into
String extension = this.file.getName().substring(this.file.getName().lastIndexOf(".") );

Thanks.

Divide by 0 when image is fully black

Accidentally the leather cover was over the camera lens, so the image was fully black, and the embedding process ended up throwing an exception:

D/***************** JPEG-STEGO ******************(17749): Embedding of 1432 bits (175+4 bytes) 
D/***************** JPEG-STEGO ******************(17749): using default code, file will not fit
D/***************** JPEG-STEGO ******************(17749): 4 coefficients examined
E/***************** JPEG-STEGO ******************(17749): java.lang.ArithmeticException: divide by zero
W/System.err(17749): java.lang.ArithmeticException: divide by zero
W/System.err(17749):    at james.JpegEncoder.WriteCompressedData(JpegEncoder.java:577)
W/System.err(17749):    at james.JpegEncoder.Compress(JpegEncoder.java:93)
W/System.err(17749):    at james.JpegEncoder.Compress(JpegEncoder.java:113)
W/System.err(17749):    at info.guardianproject.f5android.Embed.<init>(Embed.java:84)
W/System.err(17749):    at info.guardianproject.f5android.Embed.<init>(Embed.java:41)
W/System.err(17749):    at com.mayorante.ztegocam.F5Embedder.doF5(F5Embedder.java:79)
W/System.err(17749):    at com.mayorante.ztegocam.F5Embedder.embed(F5Embedder.java:63)
W/System.err(17749):    at dalvik.system.NativeStart.run(Native Method)

It could be much simpler

If this is a porting of the original f5 java library referenced in the readme, then it is unnecessarily convoluted and the efficiency isn't as good (i.e. output size). It could be much simpler.