[xmlsec] whats is the correct way to reset dsigCtx, without destroing it?

[Ranier VF]

Hi,
I'm around one problem with sign xml with function: xmlSecDSigCtxSign
func=xmlSecDSigCtxSign:file=..\src\xmldsig.c:line=274:obj=unknown:subj=dsigCtx->
result == NULL:error=100:assertion:

On first sign, all is ok, the xml is correctly signed.
On second sign, the error is raised.

Question: whats is the correct way to reset dsigCtx, without destroing it?
In case, I'm reusing struct dsigCtx.

Thank you.

Best regards,

Ranier Vilela