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

[Aleksey Sanin]

Could you please file a bug/feature request in github? I don't think it
is too difficult to do.

Aleksey

On 3/30/20 8:16 AM, Floodeenjr, Thomas wrote:
> 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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>>>
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