Manual de TAIPS-net v0.1

Copyright (c) Segurmatica. Authors: Nelson William Gamazo Sanchez, Jorge Lodos Vigil.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the Section entitled "GNU Free Documentation License".

Introducción.

El sistema TAIPS-net (Traffic Analysis and Intrusion Prevention System) es una combinación de los proyectos Honeywall ( honeynet.org) y Nepehentes ( nepenthes.mwcollect.org ). El objetivo que persigue este sistema es integrar sistemas de potes de miel de baja interacción con funcionalidad de IDS/IPS, captura y análisis de tráfico en una sola computadora. TAIPS-net es un sistema de código abierto que se mantiene bajo licencia GPLv2.

La posibilidad de funcionar con una sola interfaz de red se adicionó a Honeywall como un modo adicionalal modo puente existente, nombrado modo simple,. El uso del modo de trabajo puede seleccionarse durante la instalación y después de instalado a través de la interfaz menú presente en el Honeywall.

A continuación se describen las diferencias con respecto a la arquitectura entre en los dos modos de funcionamiento de TAIPS-net y se explican los pasos para modificar el Honeywall una vez instalado para obtener una instalación de TAIPS-net.

La versión 1.1 de Honeywall incluye las reglas distribuidas para Snort por la compañía Sourcefire. Esto establece limitaciones a la distribución comercial de estas reglas, que no tienen una licencia de código abierto. Por esta razon estas reglas no se usan en TAIPS-net. En su lugar se incluyen las reglas mantenidas por la comunidad.

1. Arquitectura de la red de potes de miel.

El objetivo del proyecto Honeywall es funcionar como un IDS/IPS y analizador de tráfico en línea, para los potes de miel que se instalen detrás de el de forma que su presencia sea indetectable para los atacantes. El Honeywall opera con la arquitectura que se muestra en la Figura 1 , y garantiza niveles mínimos de protección contra ataques que provengan de los portes de miel una vez comprometidos utilizando las características IPS del Snort (Snort inline). También incluye un Sistema de Detección de Intrusos basado en Snort para señalizar los ataques recibidos y un conjunto de herramientas para recolectar datos relativos a los ataques como son la captura del tráfico de red, análisis de sesiones en las conexiones, estadísticas de las conexiones y una aproximada identificación del sistema origen del ataque.

Figura 1. Arquitectura de red utilizada para la captura automática.

Si bien la arquitectura utilizada es ideal para la instalación de potes de miel de alta interacción el sistema exige los siguientes requerimientos mínimos:

• Al menos tres interfaces de red.

• Necesita máquinas independientes para los potes de miel a instalar.

Estos requerimientos son limitaciones importantes en el uso de forma masiva de estas tecnologías.

1.1 Limitaciones del proyecto Honeywall.

Tres interfaces de red.

Para conectar el Honeywall hacen falta al menos dos puertos de red. Las 2 primeras interfaces se usan en modo bridge para analizar trafico y transmitirlo sin alteraciones a otro sistema. La tercera interfaz se usa para la administración. Es frecuente encontrar situaciones donde:

• Los puertos disponibles son limitados.

• No se puede garantizar una administración fuera de banda si se quiere administrar el honeywall desde el exterior de la DMZ (a través de Internet).

• Por las características del cableado físico, la interfaz de administración debe ser conectada en el mismo segmento de red que la interfaz que recibe el tráfico a analizar.

Máquinas independientes.

En escenarios que utilizan solamente potes de miel de baja interacción, donde el alcance del ataque es controlado por el sistema que simula determinados servicios, y además se desean aprovechar las funcionalidades del Honeywall como IDS/IPS, captura y análisis de tráfico, puede perfectamente integrarse en un solo sistema operativo la funcionalidad del Honeywall y los potes de miel de baja interacción. Todas las desventajas anteriores pueden solucionarse incorporando los potes de miel de baja interacción dentro del Honeywall y utilizando este con una sola interfaz de red como se muestra en la Figura 2 .

Figura 2. Arquitectura de la red de pote de miel con una solo interfaz de red.

La integración del Honeywall con potes de miel de baja interacción es muy útil, por ejemplo, para el despliegue de sensores que incluyen funcionalidad de captura de programas malignos. El uso de una sola interfaz de red facilita la instalación y permite usar el Honeywall como IDS.

En el capitulo siguiente se explican los cambios a realizar a un Honeywall previamente instalado para convertirlo en un sistema TAIPS-net.

2. Cambios al Honeywall para habilitarle el modo simple.

Para instalar el Honeywall se requieren tres interfaces de red en la computadora. Usando TAIPS-net se necesita solamente 1. Un honeywall previamente instalado puede convertirse en un sistema TAIPS-net. En este capitulo se describen los cambios a realizar a un Honeywall previamente instalado para convertirlo en un sistema TAIPS-net que use una sola interfaz de red. Los cambios que se explican se realizan para la version 1.1 de Honeywall y la versión 0.1.7 del Nepenthes. Los pasos a realizar son 7:

1. Copiar los scripts modificados.

2. Crear las variables de Honeywall.

3. Instalar paquetes para nepenthes.

4. Ejecutar menu y cambiar al modo simple.

5. Remover las interfaces de red innecesarias.

6. Opcionalmente, cambiar y/o actualizar las reglas del Snort.

7. Usuarios por defecto.

A continuación se describe cada paso.

2.1 Copiar los scripts modificados. Script

Los scripts modificados están contenidos en un archivo compactado que contiene además tres ficheros de configuración. Usted puede descargar estos Scripts desde este enlace. Los ficheros de configuración cambian los puertos activos a los servicios siguientes:

• SSH al 2222

• Https al 4443

• SMTP al 2225

El cambio de los puertos es necesario porque el pote de miel de baja interacción usa los puertos originales de estos servicios para simular vulnerabilidades.

A continuación se describe donde debe ser copiado el contenido de cada carpeta:

• Crontab: Contiene el fichero crontab y debe ser copiado a /etc/

• Dlg: Contiene dos scripts que modifican la interfaz menu.

o SetupHoneywall.sh copiar a /dlg/

o ModeConfig.sh copiar a /dlg/config/

• Httpd: Contiene fichero de configuración del apache para Walleye. Copiar a /etc/walleye/

• Init.d: contiene scripts que inicio modificados. Copiar a /etc/init.d/

• Opt: Instalación del nepenthes copiar a /opt/

• Postfix: Fichero de configuración del postfix. Copiar a /etc/postfix.

• Single_mode: Contiene scripts modificados. Copiar a /etc/single_mode/

• Ssh: Contiene fichero de configuración del servicio ssh. Copiar a /etc/ssh/

Una vez que se tienen los scripts copiados antes de usarlos es necesario crear varias variables usadas por ellos con la herramienta hwctl del Honeywall. Estas variables son similares a las que usa Honeywall y se pueden ver todas con el comando: hwctl -a

2.2 Crear las variables de Honeywall.

Hay que crear tres variables. Ellas son:

• HwSINGLE_MODE_ENABLE: Especifica si el modo simple esta habilitado.

•HwS_IFACE: Especifica la única interfaz utilizada en modo simple.

• HwNEPENTHES_ENABLE: Especifica si nepenthes estará habilitado.

Se crean utilizando el comando hwctl de la forma siguiente:

1. hwctl HwSINGLE_MODE_ENABLE=no

2. hwctl HwS_IFACE =eth0

3. hwctl HwNEPENTHES_ENABLE =no

Una vez creadas las variables se puede pasar a habilitar el modo simple y nepenthes.

2.3 Instalación de paquetes para nepenthes.

Para habilitar nepenthes se requiere instalar varios paquetes que dependen de la funcionalidad que se habilite. Una información detallada puede obtenerse en el sitio de Nepenthes (http://nepenthes.mwcollect.org). Los siguientes paquetes son necesarios para la version 0.1.7 del Nepenthes soportada por TAIPS-net.

adns-1.2-1.el4.rf.i386.rpm

curl-7.12.1-3.i386.rpm

libidn-0.5.6-1.i386.rpm

2.4 Usar la interfaz menu para cambiar al modo simple y habilitar Nepenthes.

Una vez instalados los scripts modificados el proceso de configuración y puesta en marcha del modo simple es similar a la manera que se configura el Honeywall porque utiliza la misma interfaz menú. El modo simple, permite operar con una sola interfaz de red, y habilitarle las posibilidades de captura de programas malignos. Se puede cambiar de un modo a otro recordando que en modo puente necesitando las tres interfaces de red o al menos dos sino se quiere interfaz web de administración.

La configuración del modo de operación una vez instalado se realiza con la Interfaz “menu” como se muestra en la Figura 3 .

Figura 3. Configurar el Modo de Operación.

Cuando se selecciona Mode and IP Information aparece la ventana que configura el modo como se muestra en la Figura 4 .

Figura 4 Selección del Modo de Operación.

En la Figura 4 se indica cual es el modo activo en el momento de la configuración y la opción uno permite entrar a cambiar el modo de operación. También se puede ver que es posible habilitar y deshabilitar la funcionalidad de captura con la opción tres.

Al entrar en la opción uno de la ventana de la Figura 4 aparece la ventana de la Figura 5 .

Figura 5. Cambio de Modo de Operación.

La ventana anterior muestra el modo activo actual y permite cambiarlo a otro. Hay que tener en cuenta que el cambio de modo de simple a puente necesita que estén instaladas al menos dos tarjetas de red. El resto de las configuraciones son similares a las de Honeywall y mantienen el mismo significado.

A partir de la selección del modo simple el sistema corre con una sola interfaz de red, soportando a la vez captura de programas malignos y funcionalidades de captura y análisis de tráfico.

2.5 Remover las interfaces de red innecesarias.

Para remover las interfaces de red solo es necesario apagar el sistema y removerlas físicamente. Cuando sistema reinicia ya no necesita las interfaces removidas y todos los servicios funcionan con una sola interfaz.

2.6 Opcionalmente, cambiar y/o actualizar las reglas del Snort.

La versión 1.1 de Honeywall tiene incluida las reglas VRT del Snort. Si estas se quieres eliminar y dejar solo las mantenidas por la comunidad entonces se pueden seguir los pasos documentados en el sitio del Snort ( www.snort.org ).

2.7 Usuarios por defecto.

Por defecto el las credenciales para entrar al sistema son las mimas que las de Honeywall. Hay dos usuarios:

1. nombre de usuario: roo Contraseña: honey

2. nombre de usuario: root Contraseña: honey.

GNU Free Documentation License
Version 1.2, November 2002

Copyright (C) 2000,2001,2002 Free Software Foundation, Inc. 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.

0. PREAMBLE

The purpose of this License is to make a manual, textbook, or other functional and useful document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.

This License is a kind of "copyleft", which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software.

We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference.

1. APPLICABILITY AND DEFINITIONS

This License applies to any manual or other work, in any medium, that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. Such a notice grants a world-wide, royalty-free license, unlimited in duration, to use that work under the conditions stated herein. The "Document", below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as "you". You accept the license if you copy, modify or distribute the work in a way requiring permission under copyright law.

A "Modified Version" of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language.

A "Secondary Section" is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document's overall subject (or to related matters) and contains nothing that could fall directly
within that overall subject. (Thus, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them.

The "Invariant Sections" are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License. If a section does not fit the above definition of Secondary then it is not allowed to be designated as Invariant. The Document may contain zero Invariant Sections. If the Document does not identify any Invariant Sections then there are none.

The "Cover Texts" are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may be at most 25 words.

A "Transparent" copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, that is suitable for revising the document straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup, or absence of markup, has been arranged to thwart or discourage subsequent modification by readers is not Transparent. An image format is not Transparent if used for any substantial amount of text. A copy that is not "Transparent" is called "Opaque".

Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML, PostScript or PDF designed for human modification. Examples of transparent image formats include PNG, XCF and JPG. Opaque formats include proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML, PostScript or PDF produced by some word processors for output purposes only.

The "Title Page" means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, "Title Page" means the text near the most prominent appearance of the work's title, preceding the beginning of the body of the text.

A section "Entitled XYZ" means a named subunit of the Document whose title either is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in another language. (Here XYZ stands for a specific section name mentioned below, such as "Acknowledgements", "Dedications", "Endorsements", or "History".) To "Preserve the Title" of such a section when you modify the Document means that it remains a
section "Entitled XYZ" according to this definition.

The Document may include Warranty Disclaimers next to the notice which states that this License applies to the Document. These Warranty Disclaimers are considered to be included by reference in this License, but only as regards disclaiming warranties: any other implication that these Warranty Disclaimers may have is void and has no effect on the meaning of this License.

2. VERBATIM COPYING

You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3.

You may also lend copies, under the same conditions stated above, and you may publicly display copies.

3. COPYING

IN QUANTITY If you publish printed copies (or copies in media that commonly have printed covers) of the Document, numbering more than 100, and the Document's license notice requires Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The front cover must present the full title with all words of the title equally prominent and visible. You may add other material on the covers in addition. Copying with changes limited to the covers, as long as they preserve the title of the Document and satisfy these conditions, can be treated as verbatim copying in other respects.

If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages.

If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a computer-network location from which the general network-using public has access to download using public-standard network protocols a complete Transparent copy of the Document, free of added material. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public.

It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document.

4. MODIFICATIONS

You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version:

A. Use in the Title Page (and on the covers, if any) a title distinct from that of the Document, and from those of previous versions (which should, if there were any, be listed in the History section of the Document). You may use the same title as a previous version if the original publisher of that version gives permission.
B. List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together with at least five of the principal authors of the Document (all of its principal authors, if it has fewer than five), unless they release you from this requirement.
C. State on the Title page the name of the publisher of the Modified Version, as the publisher.
D. Preserve all the copyright notices of the Document.
E. Add an appropriate copyright notice for your modifications adjacent to the other copyright notices.
F. Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below.
G. Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document's license notice.
H. Include an unaltered copy of this License.
I. Preserve the section Entitled "History", Preserve its Title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section Entitled "History" in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence.
J. Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for previous versions it was based on. These may be placed in the "History" section. You may omit a network location for a work that was published at least four years before the Document itself, or if the original publisher of the version it refers to gives permission.
K. For any section Entitled "Acknowledgements" or "Dedications", Preserve the Title of the section, and preserve in the section all the substance and tone of each of the contributor acknowledgements and/or dedications given therein.
L. Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers
or the equivalent are not considered part of the section titles.
M. Delete any section Entitled "Endorsements". Such a section may not be included in the Modified Version.
N. Do not retitle any existing section to be Entitled "Endorsements" or to conflict in title with any Invariant Section.
O. Preserve any Warranty Disclaimers.

If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version's license notice. These titles must be distinct from any other section titles.

You may add a section Entitled "Endorsements", provided it contains nothing but endorsements of your Modified Version by various parties--for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard.

You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one.

The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version.

5. COMBINING DOCUMENTS

You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers.

The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work.

In the combination, you must combine any sections Entitled "History" in the various original documents, forming one section Entitled "History"; likewise combine any sections Entitled "Acknowledgements", and any sections Entitled "Dedications". You must delete all sections Entitled "Endorsements".

6. COLLECTIONS OF DOCUMENTS

You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.

You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.

7. AGGREGATION WITH INDEPENDENT WORKS

A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, is called an "aggregate" if the copyright resulting from the compilation is not used to limit the legal rights of the compilation's users beyond what the individual works permit. When the Document is included in an aggregate, this License does not apply to the other works in the aggregate which are not themselves derivative works of the Document.

If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one half of the entire aggregate, the Document's Cover Texts may be placed on covers that bracket the Document within the aggregate, or the electronic equivalent of covers if the Document is in electronic form. Otherwise they must appear on printed covers that bracket the whole aggregate.

8. TRANSLATION

Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail.

If a section in the Document is Entitled "Acknowledgements", "Dedications", or "History", the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title.

9. TERMINATION

You may not copy, modify, sublicense, or distribute the Document except as expressly provided for under this License. Any other attempt to copy, modify, sublicense or distribute the Document is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance.

10. FUTURE REVISIONS OF THIS LICENSE

The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See http://www.gnu.org/copyleft/.

Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License "or any later version" applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation.

If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation.

ADDENDUM: How to use this License for your documents

To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page:

Copyright (c) YEAR YOUR NAME.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
A copy of the license is included in the section entitled "GNU Free Documentation License".

If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the "with...Texts." line with this:

with the Invariant Sections being LIST THEIR TITLES, with the Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.

If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation.

If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.

Contacto: Email: Grupo de Soporte Técnico
Teléfonos: 870-3536 al 38, ext 112