Forum Discussion
Michael_A__Fied
Nimbostratus
NimbostratusBroken b64 decoding
Following this article:
http://devcentral.f5.com/wiki/default.aspx/iRules/LTMMaintenancePage.html
I have a nicely implemented maintenance page.
I want to add a new png file in b64 encoding, and all went well except that the decoding seems to break about 30% down.
The image is about 700x700 pixels, in png format. Using the web-based decoder at http://www.motobit.com/util/base64-decoder-encoder.asp I can confirm that the file is b64 encoded and decoded properly.
File size is about 95k - is that even a factor?
Any ideas would be great at this point.
8 Replies
hoolioCirrostratus
I haven't seen any posts about the base64 decode failing. Maybe it's the format of the encoded string in the file? It should be in the format of:
"base64encodedtext",
with no new lines or carriage returns in between the double quotes.
If that doesn't solve the problem, can you elaborate on how the decoding is breaking 30% through the image?
Aaron
Michael_A__FiedThe image has been properly formatted with quotes and comma. We use other images that work just fine (albeit they are smaller images).
The image properties are transmitted correctly - pixels of size (683 x 730).
The first 200 or so pixels are rendered correctly, and then the rest is shown as white.
I took the same properly formatted string, used the online decoder, and it renders correctly.- hoolioAre there any spaces in the base64 encoded text? If so, I think they'd need to be replaced with +. Are you okay with posting the encoded text?
Aaron - hwidjaja_37598
Altostratus
Could it be due to there are '\r' characters in your base64? What about trying to remove it in step 4:
tr -d '\n|\r' < file_with_newlines > file_without_newlines
Or, try to verify your base64 in LTM (eg. file_with_newlines):
openssl enc -d -base64 -in file_with_newlines -out file.png - hwidjaja_37598Correction, the tr command should be:
tr -d '\n\r' < file_with_newlines > file_without_newlines - hwidjaja_37598Or, copy the png file (eg. image.png) to LTM and run this:
openssl enc -base64 -in image.png | tr -d '\n' > /var/class/maint.logo.png.class
Sorry for spamming :D - Michael_A__FiedThanks y'all for your assistance - the file was formatted correctly all along from the get-go.
Seems like there's a upper limit on the size of an external class file.
From F5 Support:One of my colleagues is working on an AskF5 solution article, but it is not yet ready for publication. He tells me that the maximum size of a list item (not including the surrounding double-quotes and trailing comma) is 65520 bytes.
So all we did was split the file into smaller segments and it worked just fine. - hoolioThanks for posting the issue/solution.
Aaron
