EncodeHex() in Windows crashes with Einhugur binary string

Targets Windows
#1

feedback://showreport?report_id=29250

This bug is only a problem in Windows, not in Mac, Linux or Web Edition. It is not an error in Einhugur’s plugin (I used the latest v10.2.1) but in Xojo. I was using Xojo 2013 b5, but it was there in previous non-beta versions. It was not a problem in RS that I remember as I have this code in the current app.

Convert a string to an encrypted binary string using Einhugur’s plugin:

Dim returnString, tempString As String
Dim tempInt, tempInt2 As Integer

returnString = Encrypt(Salt + OriginalText, PassKey, 0) 'This part works OK
returnString = EncodeHex(returnString, True) 'this is where Windows gives an ‘XYZ application has stopped working’ error. EncodeHex inserts spaces and makes the Hex uppercase

I am not sure if there is something funny in the Einhugur binary string, but it seems OK in the debugger and as I said above it works fine in Mac, Web and Linux.

Workarounds:
The workaround is to Hex the binary string manually — this works in Windows:

'EncodeHex crashes in Windows, so manually Hex the binary string
returnString = “”
tempInt2 = LenB(tempString)
For tempInt = 1 to tempInt2
returnString = returnString + Right(“0” + Hex(Asc(Mid(tempString, tempInt, 1))), 2) + " "
next
if right(returnString, 1) = " " then returnString = left(returnString, len(returnString) - 1) 'remove trailing space

#2

Maybe you ask Björn about how he builds the string…

#3

Your case occurs for any string or just one specific string? EncodeHex() hangs even with EncodeHex(returnString, False) ? As you know the result of the Encryt(), can you replace this line (to check if the guilt comes from there) by a DecodeHex() to obtain the same result and check if the following EncodeHex() will hang?

#4

The string is raw binary data without encoding since its encrypted. I am guessing the EncodeHex function does something internally that assumes encoding. So you would get random crashes passing in binary data to it.

#5

I recall reporting something similar on the mailing list a few months ago.

#6

Well I have no idea whats wrong but the following encodes every byte value just fine
This suggest something else is going on - but I’m not sure what

Dim returnString As String

dim mb as new memoryblock(256)

for i as integer = 0 to 255
mb.byte(i) = i
next

returnString = EncodeHex(mb, True)

break

#7

Could be great trying to isolate the origin as I told, with few tests.
If we can’t reproduce the problem without the Encrypt() part (a specific content causing the problem), Björn will need to check the case more deeply.

#8

Is usually character combination that means something in some text encoding and not a specific byte code that creates such crash. Win32 API calls are very sensitive to getting different encoding than expected.

#9

I suppose he could give us the hex codes of the string that crashes ?

And better yet, try to execute that string on his system. A string created from the hex codes.

#10

Remember this only has a problem with Windows (tests OK on Mac, Linux and WE).

Try the following under Windows:

tempString = Encrypt("!VRkZ$$t4#Rstest123", "v6mX??+q0Q)B", 0) 'This returns ‘??{%<??bJ??t??*??z+?’

tempString = EncodeHex(tempString, True) 'this returns Hex ‘CF CF 7B 25 3C D1 81 62 4A 04 BB 74 BD 89 2A C9 F2 7A 2B BD’ on Mac, but crashes under Windows

#11

In the debugger, what is the encoding of tempString before you try to run EncodeHex?

(Both platforms would be helpful)

#12

No encoding, just:

Dim returnString, tempString As String

I tried to place a DefineEncoding command after the encrypt plus a MidB(tempString, 0) but neither helped.

#13

For a bug report and attach a sample project. I’d really like us to see this in action.

#14

I have added an attachment to the FeedBack report. Run it under Windows and click the ‘EncodeHex’ button a couple of times and Windows will complain that the app has stopped working. Clicking the ‘non-EncodeHex’ button does a manual EncodeHex().

Interestingly, placing the code directly in the button rather than calling a method doesn’t seem to cause the crash.

It might also be the particular Salt, PassKey and password I am using, but I don’t think so, since they are normal ASCII characters.

#15

Remove the calls to the plugin & see what happens
If you get no crashes without using the plugin then you’ve probably isolated it to something about using the plugin

The code I pasted above I’ve run in a loop about 100000 times and it encodes it all possible byte values each time in that loop with out problems.

Some thing else is the issue

#16