FirmaSAT features

Summary | Supported XML document types | Supported supplements | New in the Latest Version | Contact

Summary of Features

FirmaSAT enables the user to analyze and sign CFDi Comprobante documents as specified by the Servicio de Administración Tributaria (SAT) in Mexico. It also supports Retenciones, Contabilidad electrónica and Controles volumétricos documents.

sign a given XML file directly by creating and adding the `sello` field and (at the user's option) the `certificado` and `noCertficado` fields
make the signature (`sello`) string in base64 format given an XML file, the private key file and its password
validate an XML file for the correct SAT form
verify a signature in an XML file using either the encapsulated `certificado` field or a separate X.509 certificate file
create the "piped-string" (cadena) required for the signature from an XML file
compute the hash digest of the piped string
extract the digest from the signature
form the cadena original del timbre fiscal digital del SAT from the `tfd` element in a CFDi document.
verify the `selloSAT` field in the `tfd` element.
do all the above for a Retenciones document with `Sello`, `Cert` and `NumCert` fields (see Retenciones).
do all the above for Contabilidad electrónica and Controles volumétricos^** documents.
extract the serial number and start and expiry dates of the certificate, either from the `certificado` field in an XML file or from the .CER file directly.
extract a given attribute from the XML file
convert a certificate file to base64 format suitable for the `certificado` field.
check that a private key and certificate are matched.
produce a private key in base64 format suitable for the the `llaveCertificado` element of a `Cancelacion` XML document.
create a PFX (PKCS-12) file in the base64 form required by some PACs to cancel an invoice.
save a key file with a new password.

FirmaSAT is a fast, stand-alone product that does not use any slow external XML or crypto libraries. In particular, FirmaSAT does not use OpenSSL in any form.

Supported XML document types

The following types of XML documents are supported

cfdi:Comprobante v4.0 with optional tfd:TimbreFiscalDigital v1.1
cfdi:Comprobante v3.3 with optional tfd:TimbreFiscalDigital v1.1
cfdi:Comprobante (legacy) v3.2 with optional tfd:TimbreFiscalDigital v1.0
retenciones:Retenciones v2.0 with optional tfd:TimbreFiscalDigital v1.1
retenciones:Retenciones v1.0 with optional tfd:TimbreFiscalDigital
catalogocuentas:Catalogo
BCE:Balanza
PLZ:Polizas
RepAux:RepAuxFol
AuxiliarCtas:AuxiliarCtas
sellodigital:SelloDigitalContElec
controlesvolumetricos:ControlesVolumetricos (versions 1.1 and 1.2 only)^**

^** Only versions 1.1 and 1.2 of ControlesVolumetricos are supported. We will not be supporting the latest changes in 2022.

Supported supplements

FirmaSAT includes support for all the supplements listed on Actualización Factura electrónica – Reforma Fiscal 2022, Complementos y complementos concepto de factura , Documento Electrónico que ampara Retenciones e Información de Pagos and Complemento Carta Porte as at 8 December 2021.

Complementos

aerolineas.xsd
cartaporte.xsd
cartaporte20.xsd
certificadodedestruccion.xsd
cfdiregistrofiscal.xsd
ComercioExterior10.xsd
ComercioExterior11.xsd
consumodecombustibles.xsd
consumodecombustibles11.xsd
detallista.xsd
divisas.xsd
donat11.xsd
ecb.xsd
ecc.xsd
ecc11.xsd
ecc12.xsd
GastosHidrocarburos10.xsd
implocal.xsd
ine10.xsd
ine11.xsd
IngresosHidrocarburos.xsd
leyendasFisc.xsd
nomina11.xsd
nomina12.xsd
notariospublicos.xsd
obrasarteantiguedades.xsd
pagoenespecie.xsd
Pagos10.xsd
Pagos20.xsd
pfic.xsd
psgecfd.xsd
renovacionysustitucionvehiculos.xsd
servicioparcialconstruccion.xsd
spei.xsd
TimbreFiscalDigital.xsd
TuristaPasajeroExtranjero.xsd
valesdedespensa.xsd
vehiculousado.xsd

Complementos Concepto

AcreditamientoIEPS.xsd
iedu.xsd
terceros11.xsd (CDFi v3.3 only)
ventavehiculos11.xsd

Retenciones Complementos

arrendamientoenfideicomiso.xsd
dividendos.xsd
enajenaciondeacciones.xsd
fideicomisonoempresarial.xsd
intereses.xsd
intereseshipotecarios.xsd
operacionesconderivados.xsd
pagosaextranjeros.xsd
planesderetiro.xsd
premios.xsd
sectorfinanciero.xsd
TimbreFiscalDigital.xsd

New in the Latest Version

Contact us

For more information please send us a message.

This page last updated 10 September 2025