[xmlsec] Can't decrypt GCM based algorithms

[Timothy Legge]

Hi

It also seems to be an issue with a IdP SAMLResponse from okta:

I have attached the xml as test xml and the base64 version as well as
the private key (that private key is from perl-Net-SAML2 and is
already public so it is fine to post).  My perl XML::Enc module
decrypts this file without any issues.

I am continuing to review.

Tim

xmlsec1 --decrypt --privkey-pem sign-private-rsa.pem test.xml
func=xmlSecXPathDataExecute:file=xpath.c:line=246:obj=unknown:subj=xmlXPtrEval:error=5:libxml2
library function
failed:expr=xpointer(id('_040a0aae3380dc9275ae08c24a8ddd72')); xml
error: 0: NULL
func=xmlSecXPathDataListExecute:file=xpath.c:line=330:obj=unknown:subj=xmlSecXPathDataExecute:error=1:xmlsec
library function failed:
func=xmlSecTransformXPathExecute:file=xpath.c:line=430:obj=xpointer:subj=xmlSecXPathDataListExecute:error=1:xmlsec
library function failed:
func=xmlSecTransformDefaultPushXml:file=transforms.c:line=2108:obj=xpointer:subj=xmlSecTransformExecute:error=1:xmlsec
library function failed:
func=xmlSecTransformCtxXmlExecute:file=transforms.c:line=1044:obj=xpointer:subj=xmlSecTransformPushXml:error=1:xmlsec
library function failed:
func=xmlSecTransformCtxExecute:file=transforms.c:line=1092:obj=unknown:subj=xmlSecTransformCtxXmlExecute:error=1:xmlsec
library function failed:
func=xmlSecKeyDataRetrievalMethodXmlRead:file=keyinfo.c:line=1108:obj=retrieval-method:subj=xmlSecTransformCtxExecute:error=1:xmlsec
library function failed:
func=xmlSecKeyInfoNodeRead:file=keyinfo.c:line=121:obj=retrieval-method:subj=xmlSecKeyDataXmlRead:error=1:xmlsec
library function failed:node=RetrievalMethod
func=xmlSecKeysMngrGetKey:file=keys.c:line=1234:obj=unknown:subj=xmlSecKeyInfoNodeRead:error=1:xmlsec
library function failed:node=KeyInfo
func=xmlSecEncCtxEncDataNodeRead:file=xmlenc.c:line=779:obj=unknown:subj=unknown:error=45:key
is not found:encMethod=aes256-gcm
func=xmlSecEncCtxDecryptToBuffer:file=xmlenc.c:line=596:obj=unknown:subj=xmlSecEncCtxEncDataNodeRead:error=1:xmlsec
library function failed:
func=xmlSecEncCtxDecrypt:file=xmlenc.c:line=524:obj=unknown:subj=xmlSecEncCtxDecryptToBuffer:error=1:xmlsec
library function failed:
Error: failed to decrypt file
Error: failed to decrypt file "test.xml"

Timothy Legge
timlegge at gmail.com
timlegge at cpan.org

On Tue, Mar 29, 2022 at 1:25 PM Timothy Legge <timlegge at gmail.com> wrote:
>
> perfect.  I do get errors but my laptop is home at the moment.  I will test again tonight and let you know.
>
> Tim
>
> On Tue., Mar. 29, 2022, 12:57 p.m. Aleksey Sanin, <aleksey at aleksey.com> wrote:
>>
>> Well, the gcm code for openssl is here:
>>
>> https://github.com/lsh123/xmlsec/blob/4b6ab2d86b71f8642f19ab3b7a0777984b6bce9a/src/openssl/ciphers.c#L80
>>
>> so adding printfs in these functions would help.
>>
>> Do you get any errors?
>>
>> Aleksey
>>
>> On 3/29/22 11:51 AM, Timothy Legge wrote:
>> > Hi
>> >
>> > I am working on adding support for aes*-gcm to perl's XML::Enc.  I can:
>> >
>> > 1. Decrypt SAML responses encrypted with aes*-gcm using XML::Enc
>> > 2. Decrypt xmlsec encrypted aes*-gcm XML using XML::Enc
>> > 3. Encrypt XML using aes*-gcm with XML::Sec
>> > 4. Decrypt XML that was encrypted with XML::Sec using ases*-gcm
>> >
>> > However, I cannot use xmlsec to decrypt XML::Sec encrypted XML that
>> > uses aes*-gcm.
>> >
>> > I can't think of any issues that would allow me to encrypt and decrypt
>> > XML successfully with XML::Enc but not allow xmlsec to decrypt those
>> > files.
>> >
>> > I was wondering if there is a debug flag for XML sec that would allow
>> > me to output the following:
>> >
>> > 1. base64 of the CipherValue it reads from the XML file
>> > 2. base 64 of IV
>> > 3 base64 of encrypted data
>> > 4 base 64 of the tag
>> > 5 base 64 of the key
>> >
>> > I don't mind adding some print debugging and recompiling if you can
>> > point me to a starting place.  It has been a while since I wrote much
>> > C but I have no issues.  Finding the correct spot though...
>> >
>> > Tim
>> >
>> > Timothy Legge
>> > timlegge at gmail.com
>> > timlegge at cpan.org
>> > _______________________________________________
>> > xmlsec mailing list
>> > xmlsec at aleksey.com
>> > http://www.aleksey.com/mailman/listinfo/xmlsec
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