Snapchat is a photo messaging application available for iOS and Android devices. This app helps in exchanging images and videos between contacts. What is special about this app is it deletes the image after the viewing time is over. Say if you send a image to a friend with a time limit of 10 seconds,he can view the image for a maximum of 10 seconds.
I started looking around for how snapchat stores its images till they are opened and found that they store the image in the app’s internal data folder which can be easily accessed if you have a rooted device. So i copied to *.jpg.nomedia file onto my computer and tried to open it but they had used a AES-128 encryption. I used the app’s apk file to see if i can find the key for encryption and it was hardcoded in the app in the crpyto folder under util in the com.snapchat.android package. I then decrypted the image using that key .
So now that i had all the essentials i made a small android widget for saving the images . You need a rooted phone to use this app. Download the source files from my github directory and compile it using eclipse. Install it on your phone and add the widget to your homescreen. Everytime you receive a snap open the app let the image complete loading .. go to your homescreen and press the button. The image will be at “/sdcard/Snapchat/” and it should also be there in your gallery.
Github directory : https://github.com/shady33/snapget-decrpyt
Laksh Bhatia 