Decode Base64
Amjan Bouchard
I just added a custom HMAC, if the result of this isnt what your after then its just a case of running the result through the base64 encode action. I will signup to coinbase when i get a chance and test it properly.
However there is also a base64 encode action in the plugin, it takes no longer to have that run - just reference the plugins output as the base64 input and the output will very quickly become the latter of the above.
That would be essentially the same. So what do I do to decode it from base64? I've looked at the base64 module, but it takes a bytes object as an argument, and I can't think of the way to present str as bytes, because if I try to construct a bytes object, Python will try to encode the string, which I don't need.
Now, that being more or less clear, let's move on to base64 encoding, which is also an encoding of sorts, but has a slightly different meaning.Suppose you have some binary data (i.e. bytes) that may mean anything (in my case it's a bunch of floats). Now you want to represent this binary array with a string. That's what base64 encoding means: you have your bytes represented as an ASCII string.
Base64 means 6 bit, so in a base64-encoded string a single character stands for 6 bits of your data. That is why base64-encoded strings need to have the length that is a multiple of 4: otherwise the number of bytes encoded will be not integer.
Finally, to decode from base64 you need an ASCII string. A Unicode string won't do, there can only be characters from the base64 alphabet. Base64 module does the job in Python. The base64.b64decode() function takes a byte string as the argument. In Python 2 it means: str. In Python 3 it means: bytes. So if you have a str, such as
And by the way, this will return a bytes object, so it's really up to you how to treat those bytes then. Maybe it's my floats, but maybe you should try to decode it as ASCII :)In Python 2 however it will be just a str. Anyway, have a look at struct for the tools to unpack your data from those bytes.
On Python 2, encode('ascii') won't effectively do anything because it's applied to str. So it will do an implicit conversion to Unicode first, and then do what you want (convert it back to ASCII). decode('ascii') will return a unicode object on Python 2.
I'm new to using python and flask and really like it. I'm returning a query to be displayed in a jinja template and one of my columns being returned has base64 data. How do I decode that data and display it.
the default behaviour of file input component is to store in base64 encoded string
this is allowing me to access the base64 string of the image/ that i picked from my system
i want to upload the image, to S3signedurl using put mehtod, i am sending the body as binary
is there a way to "not encode the file to base64", or any way to convert back the fille(image) back to orignal?
as you can see from the screenshot that, the same image picked from fileinput is viewable in image component, it means the the image component decodes the base64 string
The easiest thing which popped into my mind was to use the expect and actual. Then it worked fine for Android, but it was not possible to make the actual method for iOS to decode a simple base64 string.
@dalewking:
The Ktor Base64 decoder seems to be an internal Ktor API which I could not use in my KMM project.
It is also marked as deprecated(?) in the docs: -base64.html
It would be amazing if I could find a workaround to use it.
Hello all,
I am working on something I have never worked on before and I really do not know where to go from here and I am hoping someone might have some direction for me to attempt trying to get this parsed to Elasticsearch properly.
I have been given a sample JSON file to parse to ES using logstash however they are requesting that we if we want to review the relevant information, we would have to decode via base64. Given that I have never worked on something like this before, I did a bit of research which led me to install the cipher plugin for logstash. As I continued down this path, I realized that I truly did not know where to go from here so I am hoping someone can assist on where to at least start as I attempt to write this pipeline. I have provided what I have so far (my filter is where my issue is) along with a sample record, hoping for some reference documentation or an understanding of how to write this.
Badger, just to clarify, your response just used one of his fields as an example right? Since he has some fields encoded in base64 and others not i figured you just used "message" as an example but in reality based on his log example do we need to switch:
So far I have tried a simple bash file containing python -m base64 -d $1 but this command expects a filename not a string. Is there another non-interactive command (not necessarily in a Python module) that I can run from the command line to achieve this, without having to install any extra packages? (Or if I do, something super-minimal.)
I had a few moments of hair-pulling on this one because the base64 Linux tool and also the openssl can decode, indeed. But I have this particular base64 encoded file that decodes to slightly wrong value. The few bytes do match, but then there is this presence of EF BF BD EF BF BD when I view in hexedit viewer. And then the next sequence of bytes match again when compared to the correctly decoded expected output. These weird sequence of bytes got inserted in the in-betweens, sometime as EF BF BD only.
I am trying to come up with a way to decode the Base64 we receive in an HL7 message into a PDF file and save it in a directory on our AIX machine. I thought I had the following working at one time but I am having issues. Has anyone done this before?
In this example I am using the Function Item node which allows running arbitrary JS code. The example code adds a new memo_text field with the decoded value of each memo_base64 field in your transactions array:
I am hoping to scan a QR code with the barcode scanner that is encoded via base64. I thought I found an XPath function base64Decode that might work, but I think that's possibly only available as an extension.
I believe another option would be to change your form design to wrap the call in a conditional that relies on some value in the form being filled in. For example, if you want to decode the value from a field called scanned, you could use if($scanned!='', base64-decode($scanned}, '').
Could you provide us with a file in a ZIP so we have an example that is like it is on your machine. I was not able to convert your example. Maybe if you could put your base64 file and your excel into a ZIP we would have an example.
Since you mentioned that the base64 string can come via some stream I have loaded the content of the TXT file into knime and saved it again and converted it again to see if there is a way to do it without having an original TXT file.
I am trying to decode a string returned from an REST API call and am having problems with unrecognised characters. I have been able to decode the same string in Javascript on my laptop, but not using Groovy on my C-4 hub.
As far as I can tell, I am receiving a UTF-8 string in the HTTP response, both in terms of the header settings and my ability to read it on screen. I am storing this in a String variable without setting the encoding. I then create a second String variable, taking in the byte array from a decodeBase64 call on the first variable, and setting the encoding to Unicode. When I output the result, I can see all but one of the characters, with the problematic output showing as a question mark. I know it is not being recognised because I take this decoded string and attempt to convert it to a hex string / int array, which produces an 0xfffd result, which I understand to be the indication for an unrecognised character. Does anyone have any tips?
This is a thermostat driver for Mitsubishi Wi-Fi adaptors, specifically those systems hooked into their Kumo Cloud-hosted system in the U.S. They have an option (though not documented I believe) to control the thermostats locally using an encrypted(?) message. So you do periodic call to their cloud API and get back an encoded password and a "cryptoSerial" (I'm assuming private key...). The base64 encoded password is decoded, mashed together with the text for the command (turn on the heating), then a SHA-256 hash is done and a few other transformations with the crypto serial and what I assume is a Kumo public key (I didn't pay enough attention during data security at Uni). You can then send this encrypted message to the thermostat over the LAN without needing to involve the cloud.
Problem solved, needed to include the "unsigning" of the integers I was getting out of the decoded byte array, something I had used in various places a few days ago in a blind attempt to get this working, I just needed to introduce as I converted the byte array coming out of the decoding call. I'll add some sample code here later, once I tidy it up, but here's a link to the article that reminded me of this:
When decoding Base64 text, four characters are typically converted back to three bytes. The only exceptions are when padding characters exist. A single = indicates that the four characters will decode to only two bytes, while == indicates that the four characters will decode to only a single byte. For example:
Another way to interpret the padding character is to consider it as an instruction to discard 2 trailing bits from the bit string each time a = is encountered. For example, when `bGlnaHQgdw==` is decoded, we convert each character (except the trailing occurrences of =) into their corresponding 6-bit representation, and then discard 2 trailing bits for the first = and another 2 trailing bits for the other =. In this instance, we would get 6 bits from the d, and another 6 bits from the w for a bit string of length 12, but since we remove 2 bits for each = (for a total of 4 bits), the dw== ends up producing 8 bits (1 byte) when decoded.
ffe2fad269