[asterisk-bugs] [Asterisk 0015271]: [patch] BASE64_DECODE() adds garbage end end of decoded string

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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https://issues.asterisk.org/view.php?id=15271 
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Reported By:                chappell
Assigned To:                lmadsen
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Project:                    Asterisk
Issue ID:                   15271
Category:                   Functions/func_base64
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     assigned
Asterisk Version:           1.4.24 
Regression:                 No 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2009-06-04 10:16 CDT
Last Modified:              2009-09-09 15:21 CDT
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Summary:                    [patch] BASE64_DECODE() adds garbage end end of
decoded string
Description: 
This problem has two causes:

1) BASE64_DECODE() fails to null terminate its return value. This becomes
evident if first a long string is decoded and then a short one.  The short
one will have have the last part of the long string appended to it.

2) What is more, ast_base64decode() does not recognize the equals signs
which pad the end of a string the length of which is not a multiple of
three bytes. Rather than stopping, it decodes the padding as data,
producing bogus output.  
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Relationships       ID      Summary
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related to          0011018 patch for 10979 breaks IAX RSA auth
related to          0010979 [path] main/util.c missed *dst='\0'; in...
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 (0110439) kobaz (reporter) - 2009-09-09 15:21
 https://issues.asterisk.org/view.php?id=15271#c110439 
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In trunk, the base64 decoded string is properly null terminated now, but
still doesn't stop after encountering an '='

main/utils.c: Line 270
-       while (*src && (cnt < max)) {
+       while (*src && (*src != '=') && (cnt < max)) { 

Issue History 
Date Modified    Username       Field                    Change               
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2009-09-09 15:21 kobaz          Note Added: 0110439                          
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