[xmlsec] xmlsec1-1.2.16 to xmlsec1-1.2.29 decrypt problems

[Floodeenjr, Thomas]

Aleksey,

Following the progression of our code, according to this call stack:

	Application.exe!xmlParseCDSect(_xmlParserCtxt * ctxt) Line 9748	C
 	Application.exe!xmlParseContent(_xmlParserCtxt * ctxt) Line 9831	C
 	Application.exe!xmlParseInNodeContext(_xmlNode * node, const char * data, int datalen, int options, _xmlNode * * lst) Line 13682	C
 	Application.exe!xmlSecReplaceNodeBufferAndReturn(_xmlNode * node, const unsigned char * buffer, unsigned int size, _xmlNode * * replaced) Line 632	C
 	Application.exe!xmlSecReplaceNodeBuffer(_xmlNode * node, const unsigned char * buffer, unsigned int size) Line 609	C
>	Application.exe!xmlSecEncCtxDecrypt(_xmlSecEncCtx * encCtx, _xmlNode * node) Line 562	C

Inside xmlSecReplaceNodeBufferAndReturn(), we call xmlParseInNodeContext(node->parent, (const char*)buffer, size, XML_PARSE_NODICT, &results);

It looks like the call in xmlSecReplaceNodeBufferAndReturn() hard-codes the option to "XML_PARSE_NODICT", and gives us no option to pass in the XML_PARSE_HUGE parameter we need when we call xmlSecEncCtxDecrypt().

Any ideas how to get around this?

Thanks,
-Tom

-----Original Message-----
From: Aleksey Sanin <aleksey at aleksey.com> 
Sent: Friday, March 27, 2020 5:17 PM
To: Floodeenjr, Thomas <thomas_floodeenjr at mentor.com>; xmlsec at aleksey.com
Subject: Re: [xmlsec] xmlsec1-1.2.16 to xmlsec1-1.2.29 decrypt problems

Great. I am not aware of any issues with this flag. Since you posted to libxml2 mailing list, I am sure you fill get the answer shortly.

Aleksey

On 3/27/20 2:55 PM, Floodeenjr, Thomas wrote:
> Aleksey,
> 
> It seems we found the problem. Before we decrypt, we call doc = xmlReadFile( filePath, NULL, XML_PARSE_HUGE ); It seems the XML_PARSE_HUGE flag is not honored in libxml2. I am not sure if this is a bug in libxml2, or if it is a new "feature". We are looking for a way to work around this. If we hard-code it in xmlCtxtUseOptionsInternal(), i.e., ctxt->options |= XML_PARSE_HUGE;, then our code decrypts fine.
> 
> Thanks for your replies.
> 
> -Tom
> 
> 
> 
> -----Original Message-----
> From: Aleksey Sanin <aleksey at aleksey.com>
> Sent: Friday, March 27, 2020 10:32 AM
> To: Floodeenjr, Thomas <thomas_floodeenjr at mentor.com>; 
> xmlsec at aleksey.com
> Subject: Re: [xmlsec] xmlsec1-1.2.16 to xmlsec1-1.2.29 decrypt 
> problems
> 
> Hi Thomas,
> 
> I am not aware of any limitations on file sizes. I would suggest to either set a breakpoint or dump the decrypted data before the call to xmlParseInNodeContext() to see what's wrong. There are a couple options I can think of:
> 1) Decryption is completely incorrect and you will see junk in the buffer.
> 2) Decryption is correct but the data is truncated.
> 
> Let me know what do you find.
> 
> Aleksey
> 
> On 3/27/20 6:07 AM, Floodeenjr, Thomas wrote:
>> Aleksey,
>>
>> Is there a limitation with xmlsec1-1.2.29 on the size of the 
>> encrypted XML that is being decrypted? The file seems to encrypt OK, 
>> but will not decrypt. (290 MB). Smaller files work fine both ways. We 
>> are using
>> libxml2-2.9.9 and openssl-1.1.1d.  (Previously we used libxml2-2.7.8 
>> and openssl-1.0.2g, and it worked fine.)
>>
>> Thanks,
>> -Tom
>>
>> -----Original Message-----
>> From: xmlsec <xmlsec-bounces at aleksey.com> On Behalf Of Floodeenjr, 
>> Thomas
>> Sent: Thursday, March 26, 2020 12:52 PM
>> To: Aleksey Sanin <aleksey at aleksey.com>; xmlsec at aleksey.com
>> Subject: Re: [xmlsec] xmlsec1-1.2.16 to xmlsec1-1.2.29 decrypt 
>> problems
>>
>> It returns here with -1
>>
>>       if(ret != XML_ERR_OK) {
>>           xmlSecXmlError("xmlParseInNodeContext", NULL);
>>           return(-1);
>>       }
>>
>> -----Original Message-----
>> From: Aleksey Sanin <aleksey at aleksey.com>
>> Sent: Thursday, March 26, 2020 11:05 AM
>> To: Floodeenjr, Thomas <thomas_floodeenjr at mentor.com>; 
>> xmlsec at aleksey.com
>> Subject: Re: [xmlsec] xmlsec1-1.2.16 to xmlsec1-1.2.29 decrypt 
>> problems
>>
>> What error do you get?
>>
>> Aleksey
>>
>> On 3/26/20 8:26 AM, Floodeenjr, Thomas wrote:
>>> Hello,
>>>
>>> We recently upgraded from xmlsec1-1.2.16 to xmlsec1-1.2.29. We have 
>>> some data created in 1.2.16 that we can decrypt, but it fails to 
>>> decrypt in 1.2.29.
>>>
>>>                  Application.exe!xmlSecCheckNodeName(_xmlNode * 
>>> const cur, const unsigned char * name, const unsigned char * ns) 
>>> Line 210 C
>>>
>>>>                 
>>>> Application.exe!xmlSecEncCtxEncDataNodeRead(_xmlSecEncCtx * encCtx, 
>>>> _xmlNode * node) Line 696      C
>>>
>>>                  
>>> Application.exe!xmlSecEncCtxDecryptToBuffer(_xmlSecEncCtx
>>> * encCtx, _xmlNode * node) Line 597      C
>>>
>>>                  Application.exe!xmlSecEncCtxDecrypt(_xmlSecEncCtx * 
>>> encCtx, _xmlNode * node) Line 524      C
>>>
>>> Other items do decrypt fine with both versions. Any ideas what we 
>>> can look into?
>>>
>>> Thanks,
>>>
>>> -Tom
>>>
>>>
>>> _______________________________________________
>>> xmlsec mailing list
>>> xmlsec at aleksey.com
>>> http://www.aleksey.com/mailman/listinfo/xmlsec
>>>
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