I am using mitmproxy to sniff out a POST request that sends an image. However, the image seems to be sent as bytes, and I cannot figure out how to convert those bytes back to an image.
Already tried:
Copying and pasting the bytes to a file via notepad++
Using hexedit to create a new file with these bytes
Use an online hex to image converter
All of the above methods tell me the file is corrupted.
Part of stream:
START
\xff\xd8\xff\xe0\x00\x10JFIF\x00\x01\x01\x00\x00H\x00H\x00\x00\xff\xe1\x07\x88Exif\x00\x00MM\x00*\x00\x00\x00\x08\x00 \x01\x0f\x00\x02\x00\x00\x00\x06\x00\x00\x00z\x01\x10\x00\x02\x00\x00\x00 \x00\x00\x00\x80\x01\x12\x00\x03\x00\x00\x00\x01\x00\x01\x00\x00\x01\x1a\x00\x05\x00\x00\x00\x01\x00\x00\x00\x8a\x01\x1b\x00\x05\x00\x00\x00\x01\x00\x00\x00\x92\x01(\x00\x03\x00\x00\x00\x01\x00\x02\x00\x00\x011\x00\x02\x00\x00\x00\x05\x00\x00\x00\x9a\x012\x00\x02\x00\x00\x00\x14\x00\x00\x00\xa0\x87i\x00\x04\x00\x00\x00\x01\x00\x00\x00\xb4\x00\x00\x00\x00Apple\x00iPhone 7\x00\x00\x00\x00\x00H\x00\x00\x00\x01\x00\x00\x00H\x00\x00\x00\x0113.3\x00\x002022:05:22 20:33:01\x00\x00$\x82\x9a\x00\x05\x00\x00\x00\x01\x00\x00\x02j\x82\x9d\x00\x05\x00\x00\x00\x01\x00\x00\x02r\x88"\x00\x03\x00\x00\x00\x01\x00\x02\x00\x00\x88'\x00\x03\x00\x00\x00\x01\x01\x90\x00\x00\x90\x00\x00\x07\x00\x00\x00\x040231\x90\x03\x00\x02\x00\x00\x00\x14\x00\x00\x02z\x90\x04\x00\x02\x00\x00\x00\x14\x00\x00\x02\x8e\x90\x10\x00\x02\x00\x00\x00\x07\x00\x00\x02\xa2\x90\x11\x00\x02\x00\x00\x00\x07\x00\x00\x02\xaa\x90\x12\x00\x02\x00\x00\x00\x07\x00\x00\x02\xb2\x91\x01\x00\x07\x00\x00\x00\x04\x01\x02\x03\x00\x92\x01\x00
\x00\x00\x00\x01\x00\x00\x02\xba\x92\x02\x00\x05\x00\x00\x00\x01\x00\x00\x02\xc2\x92\x03\x00
\x00\x00\x00\x01\x00\x00\x02\xca\x92\x04\x00
END:
\x18\xb2\x12\x04\x8f\xd3\xb50.%\xaa\xa22K\xf3`\xf1\xfe5LHX\x90;;JN\xc8\x95\xbe\xef\x04\x90{\x9a\x82\x99*\xc9\x85b# \x0c\x81Mnb\xc7\xb7\x9c\xdf\xbb\x0f\x90y9\xef\xedC\x924Mu/\xad\xb4ko\xb0\xe4\xefm\xb8\xf4\xc7\xa1\xa6\x99\x99\x08\xde\xd9F\xc7\xc8s\xf8-U\xc6M\x04\xca\xc3\xe5\\s\xcf=y\xc5R\xb8\x1a\xd6\xf6\xaa \xf2\xf8i\x1b\xbf8\xab\x00\x8c\x86Uw\xce{\xe0\xfb\xe2\xb3RD\x12d\xc6\xbed\x84\xb8\x07\xa7\xbf\xadY\xa2,0\x89|\xb6\x95|\xc0\xfc\xe4\xf5\xf6\xac\xc2\xf6 Z\x18cT(w1\x010x\x1b\xbaf\x81^\xe5\xa8\xad\x01\x901b\xaf\x1f\x18\x1fw\x8fJ \xd4\x8a#\xba\x0f=\xd0\x12\xc0\xb7^\xfe\x99\xa0Vf\x8f\x95!\x825b\xa3\x1b\x8bapX\x0e\xd9\xad\x00\x86\x063<|\x90\x1b\x81\xcfLT2\xedm\x0bW\x08N\xe8\x83\x10\xc4\xf1\xc7\x18\xadX\x91V\xee5\xb7\x80(;\x99\xdba8\xfdj4(\xff\xd9
The image is an jpg, and the bytes seem to match JPG standard (Starting with xff, ending with xd9.)
Any help would be greatly appreciated.
Alright, got it working:
I found this link:
https://laurentmeyer.medium.com/understanding-jpeg-format-the-hard-way-57dd34abe2f1
Checked the HEX data of my request, copied the hex codes between xffxd8 and xffxd9, then used a tool on codepen to convert it back into an image.
To convert it back to an image, that worked.
Related
I know there is an image package that exist in Golang that implements encode and decode functionality, but how can I get other data from an image?. For example I am trying to get iTXt chunks from PNG images, is there any way I can do this?
#Khalil,
Looks like Go's PNG reader does not support ancillary chunks.
Check internals of https://golang.org/src/image/png/reader.go for line 87 and compare with https://www.w3.org/TR/PNG/#5ChunkOrdering.
Given a HL7 file which I know that in its TXA segment there's a byte code of an image, how can I extract that image?
I know my question might be blurry, but that's the details I have
EDIT: The TXA segment is as follows:
TXA|1|25^PathologyResultsReport|8^HTML|||||||||||||||||||908^מעבדת^פתולוגיה^^^^^^^^^^^^20110710084900|||PCFET0NUWVBFIGh0bWwgUFVCTElDICItLy9XM0MvL0RURCBYSFRNTCAxLjAgU3RyaWN0Ly9FTiIgImh0dHA6Ly93d3cudzMub3JnL1RSL3hodG1sMS9EVEQveGh0bWwxLXN0cmljdC5kdGQiPg0KPGh0bWw+PGhlYWQ+PG1ld...
+PGJyLz48L3RkPjwvdHI+DQo8dHI+PHRkPg0KPC90ZD48L3RyPg0KPC90Ym9keT4NCjwvdGFibGU+DQo8L3RkPjxTb2ZUb3ZOZXdDb2x1bW4gLz48L3RyPjxTb2ZUb3ZOZXdMaW5lIC8+DQo8L3Rib2R5Pg0KPC90YWJsZT4NCjwvYm9keT4NCjwvaHRtbD4NCg==|
Thanks in advance
From reading the documentation it appears that images are stored in this form:
OBX||TX|11490-0^^LN||^IM^TIFF^Base64^
SUkqANQAAABXQU5HIFRJRkYgAQC8AAAAVGl0bGU6AEF1dGhvcjoAU3ViamVjdDoAS2V5d29yZHM6~
AENvbW1lbnRzOgAAAFQAaQB0AGwAZQA6AAAAAABBAHUAdABoAG8AcgA6AAAAAABTAHUAYgBqAGUA~
YwB0ADoAAAAAAEsAZQB5AHcAbwByAGQAcwA6AAAAAABDAG8AbQBtAGUAbgB0AHMAOgAAAAAAAAAA~
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAASAP4ABAABAAAAAAAAAAAB~
(681 lines omitted)
1qqQS/cFpaSVeD1QP1/SX1VJfpPSfXr+tIOKrN2aSrB8OHoH1kfz2tnPLpB/6WkksJ0w5G6WKVNe~
vSisJQdhLdQjODpbznVXXDMPdBNhVtBNpOqqtkY60qYoJxQK17cUoS0v4ijYztCapqqYUKmIUJhJ~
sKqoIO2opiqr7lupIMFBBhNQmtOIzG4naS7XsQuDBLFOP/gAgAgAAKMHAACcBgAACRcAALcYAAC4~
EwAA5RoAALQXAADyBAAAnAMAAD8LAADbEQAA5CgAAJtBAABTVQAAOHAAAOyHAAA=|||||||F
This looks like a simple structure, where the image data is base64 encoded and stored as a long stream, you know its an image because it has ^IM and the image type because of ^TIFF
More specifically:
When an image is sent, OBX-2 must contain the value ED which stands for encapsulated data. The components of OBX-5 must be as described below.
The first component, source application, must be null.
Component 2, type of data, must contain IM, indicating image data.
Component 3, data subtype, must contain TIFF
Component 4, encoding, must contain Base64
Base64 encoding of non-structured (standard HL7) data, normally in an OBX (but could be anywhere) is the norm. Older systems may have a 32K or 64K byte limit, and when that happens the data will be spread over multiple segments.
The target system will first have to potentially concatenate multiple segments and then decode the Base64 encoding.
The target system must know what the expected data type is so that it can be properly displayed or further decoded/interpreted.
This would be a great question on our new StackExchange site for IT Healthcare: http://area51.stackexchange.com/proposals/51758/healthcare-it
Can anyone please explain to me how to generate an image from a remote server using simplexml and store it in a temporary image file or point me to a tutorial that would shed some light on how to do this?
Thanks!
Binary data is typically stored in XML using base64 encoding. You would run a base64 decode function over the data to get the image data.
I'm using rmagick to manipulate image files. I use the ImageList.new on each file to get started. When I apply this method to an invalid image file I get the below error which interrupts the execution of the script:
RMagick.rb:1635:in `read': Improper image header (Magick::ImageMagickError)
Therefore I would like to be able to check whether a file is a valid image file before using this method.
Any ideas?
Thanks.
You can check the format of the image. For example:
image = Magick::Image::read(file_path).first
image.format
So you can check if the format is one of the formats you expect:
image = Magick::Image::read(file_path).first
%w(JPEG GIF TIFF PNG).include? image.format
This is not based on the file name extension. It giess you the actual format of the file.
An exception seems like the perfect signal that an image is invalid... Why not simply rescue it?
If you really want to apply some other tests, you could use FastImage and request the type or size, for instance, and you will get nil if the header is corrupted.
If you are processing images of a certain format(s), you could analyze their headers to determine if they are really valid images files.
For example, the first 3 bytes of a GIF file header are "GIF", according to this GIF spec - so if you receive a file with a .gif extension, you could analyze it to verify its header matches the spec.
install mimemagic gem
gem 'mimemagic'
open stream(bytes of target image)
url="https://i.ebayimg.com/images/g/rbIAAOSwojpgyQz1/s-l500.jpg"
result = URI.parse(url).open
then check data-stream's file type
for example:
MimeMagic.by_magic(result).type == "image/jpeg"
even though as mentioned above
%w(JPEG GIF TIFF PNG).include?(MimeMagic.by_magic(result).type)
this might be more elegant
Is there a good way to see what format an image is, without having to read the entire file into memory?
Obviously this would vary from format to format (I'm particularly interested in TIFF files) but what sort of procedure would be useful to determine what kind of image format a file is without having to read through the entire file?
BONUS: What if the image is a Base64-encoded string? Any reliable way to infer it before decoding it?
Most image file formats have unique bytes at the start. The unix file command looks at the start of the file to see what type of data it contains. See the Wikipedia article on Magic numbers in files and magicdb.org.
Sure there is. Like the others have mentioned, most images start with some sort of 'Magic', which will always translate to some sort of Base64 data. The following are a couple examples:
A Bitmap will start with Qk3
A Jpeg will start with /9j/
A GIF will start with R0l (That's a zero as the second char).
And so on. It's not hard to take the different image types and figure out what they encode to. Just be careful, as some have more than one piece of magic, so you need to account for them in your B64 'translation code'.
Either file on the *nix command-line or reading the initial bytes of the file. Most files come with a unique header in the first few bytes. For example, TIFF's header looks something like this: 0x00000000: 4949 2a00 0800 0000
For more information on the TIFF file format specifically if you'd like to know what those bytes stand for, go here.
TIFFs will begin with either II or MM (Intel byte ordering or Motorolla).
The TIFF 6 specification can be downloaded here and isn't too hard to follow