# Patent

## Title
Providing multiple isolated execution environments for securely accessing untrusted content

## Abstract

A sandbox tool can create and maintain multiple isolated execution environments, simultaneously. The sandbox tool can assign a unique security label to each isolated execution environment. In order to ensure the security labels are unique, the sandbox tool, for each security label, can bind a communication socket in an abstract name space of the operating system with a name that is the same as the security label. If the operating system returns an error that the name for the communication socket is already in use, the sandbox tool can determine that the security label is already in use by another isolated execution environment or other process.

## Background
FIELD
This invention relates generally to computer security.
DESCRIPTION OF THE RELATED ART
In today's distributed computing environments, security is of the utmost importance. Due to the rise of wide-area public networks, users have unlimited access to content, e.g. data, files, applications, programs, etc., from a variety of sources. Often, the users are unaware of the origin of the content available in the public networks. Malicious entities utilize this ease of accessibility and anonymity to attack the users. For example, the malicious entities can plant viruses, Trojans, or other malicious agents in publicly available content in order to attack the users' computing systems and steal sensitive information from the users. As such, the users must treat content from unknown sources as untrusted and possibly dangerous.
Typically, to prevent attacks, the users utilize filtering programs, anti-virus programs, etc. in order to identify and block known dangerous content. These programs, however, suffer from several weaknesses. In order to properly identify and block the dangerous content, the filtering and anti-virus programs must typically be configured with the identity of the source of known dangerous content. As such, the filtering and anti-virus programs lack the ability to stop previously unknown and emerging threats. Likewise, the filtering and anti-virus programs are themselves subject to attack. Many types of dangerous content utilize weaknesses in the filtering and anti-virus programs to attack the users' computing systems using the filtering and anti-virus programs as a vehicle for attacking the users' computing systems. As such, the users lack methods to guarantee that untrusted content does not pose a threat.



BRIEF DESCRIPTION OF THE DRAWINGS
Various features of the embodiments can be more fully appreciated, as the same become better understood with reference to the following detailed description of the embodiments when considered in connection with the accompanying figures, in which:
FIG. 1 illustrates a network of computing systems in which various embodiments of the present teachings can be practiced;
FIGS. 2A and 2B illustrate an exemplary software environment for utilizing an isolated execution environment, according to various embodiments of the present teachings;
FIG. 3 illustrates components of an exemplary secure operating system including a sandbox tool, according to various embodiments;
FIGS. 4A and 4B illustrate an exemplary process for accessing untrusted content in the isolated execution environment, according to various embodiments;
FIGS. 5A and 5B illustrate exemplary interfaces for accessing untrusted content in the isolated execution environment, according to various embodiments; and
FIG. 6 illustrates an exemplary computing system which can implement the secure operating system and the sandbox tool, according to various embodiments.



DETAILED DESCRIPTION OF EMBODIMENTS
For simplicity and illustrative purposes, the principles of the present teachings are described by referring mainly to exemplary embodiments thereof. However, one of ordinary skill in the art would readily recognize that the same principles are equally applicable to, and can be implemented in, all types of information and systems, and that any such variations do not depart from the true spirit and scope of the present teachings. Moreover, in the following detailed description, references are made to the accompanying figures, which illustrate specific embodiments. Electrical, mechanical, logical and structural changes may be made to the embodiments without departing from the spirit and scope of the present teachings. The following detailed description is, therefore, not to be taken in a limiting sense and the scope of the present teachings is defined by the appended claims and their equivalents.
Embodiments of the present teachings relate to systems and methods for accessing, viewing, and running untrusted content, such as data, files, programs, and applications, without exposing a computing system to untrusted content and possibly malicious content. More particularly, a “sandbox tool” can create multiple isolated execution environments for accessing untrusted content that are isolated from each other and other processes executing on the computing system.
According to embodiments, the sandbox tool can be configured to cooperate with components of a secure operating system, such as security enhanced LinuxTM (SELinux), to create an isolated execution environment for accessing untrusted content without exposing other processes and resources of the computing system to the unfrosted content. In particular, the sandbox tool can be configured to allocate resources (storage space, memory, etc) of the computing system, which are necessary to access the untrusted content, to the isolated execution environment, and apply security polices of the operating system to the isolated execution environment such that untrusted content running in the isolated execution environment can only access the resources allocated to the isolated execution environment. As such, the user can access the untrusted content without exposing the overall computing system to any possible malicious or dangerous content.
According to embodiments, the sandbox tool can be configured to create and maintain multiple isolated execution environments, simultaneously. The sandbox tool can be configured to assign a unique security label to each isolated execution environment. For an isolated execution environment, the security label identifies the security policies applied by the operating system to the isolated execution environment, thereby, defining the levels of access the untrusted content and any other processes have to the resources of the computing system. In order to ensure the security labels are unique, the sandbox tool, for each security label, can be configured to bind a communication socket in an abstract name space of the operating system with a name that is the same as the security label.
In embodiments, to select a security label for a new isolated execution environment, the sandbox tool can be configured to select a security label, for example, randomly select the security label. Once selected, the sandbox tool can be configured to bind a communication socket in the abstract name space with a name that is the same as the selected security label. If the operating system returns an error that the name for the communication socket is already in use, the sandbox tool can determine that the security label is already in use by another isolated execution environment or other process. As such, the sandbox tool can be configured to select a different random security label and attempt to bind a communication socket in the abstract name space with a name that is the same as the newly selected security label.
By utilizing the sandbox tool, untrusted content can be accessed on a computing system without exposing the computing system to any malicious agents that may be contained in the untrusted content. As such, the untrusted content can be accessed without regard to the source of the content. Likewise, untrusted content can be accessed without the use of other security programs and applications which may be susceptible to malicious agents contained in the untrusted content. Further, by assigning the security labels utilizing the abstract name space, the sandbox tool can create multiple isolated execution environments with unique security labels even if the multiple isolated execution environments are created by different users that may not share access to the same name space and directories.
FIG. 1 illustrates an exemplary network 100 of computing systems, according to various embodiments. It should be readily apparent to those of ordinary skill in the art that the network 100 depicted in FIG. 1 represents a generalized schematic illustration and that other components may be added or existing components may be removed or modified. Moreover, the network 100 may be implemented using software components, hardware components, or combinations thereof.
As illustrated in FIG. 1, the network 100 can represent the systems of private entities, such as individuals, businesses, partnerships, companies, corporations, etc., and public entities, such as universities, governmental agencies, etc. The network 100 can include a number of computing systems, such as a user computing system 102 and remote computing systems 104. The computing systems, such as the user computing system 102 and remote computing systems 104, can include hardware resources, such as processors, memory, network hardware, storage devices, and the like, and software resources, such as operating systems (OS), application programs, and the like.
In embodiments, the user computer system 102 can include a secure OS 106, such as security enhanced Linux (“SELinux”), available from Red HatTM, Inc. In this example, SELinux implements a monolithic kernel which is configured to provide an X-Window computing environment to the user computing system 102. SELinux is a version of Linux that integrates FLASK architectural components to provide general support for the enforcement of many kinds of mandatory security policies, including those based on the concepts of type enforcement, role-based access control (“RBAC”), and multi-level security.
In embodiments, the computing systems in environment 100 can be located at any location, whether located at single geographic location or remotely located from each other. In order to communicate and share data, the user computing system 102 and the remote computing systems 104 can be coupled to one or more networks 108. The one or more networks 108 can be any type of communications networks, whether wired or wireless, to allow the computing system to communicate, such as wide-area networks (e.g. Internet) or local-area networks.
In embodiments, a user of the user computing system 102 can utilize the computing environment of the secure OS 106 to access content on the user computing system 102. The content can include any number and type of data, applications, and programs such as word processing applications, web browser applications, file sharing applications, electronic mail (e-mail) applications, multimedia applications, chat applications, etc. Likewise, the content can include files and data utilized by the applications or accessed utilizing the applications. The content accessed on the user computing system 102 can be acquired from a variety of sources. For example, the content can be installed and copied to the user computing system 102 from media such as compact discs (CDs) and digital versatile discs (DVDs). Likewise, the content can be downloaded from one or more of the remote computing systems 104 via the network 108.
In embodiments, the content accessed on the user computing system 102 may not be secure. For example, the user computing system 102 can acquire the content from one or more of the remote computing systems 104. In this example, the user computing system 102 may not know the source of the content and cannot guarantee that the content is secure. Likewise, content installed and copied from media can be untrusted and possibly insecure. As such, the content can be deemed to be untrusted and can possibly be insecure.
In embodiments, regardless of whether the content is trusted or untrusted, the user of the user computing system 102 can desire to access the content without exposing the user computing system 102 to malicious agents (e.g. viruses, Trojans, etc.). In order to allow access of the content without exposing the user computing system 102 to malicious agents, the user computing system 102 can include a sandbox tool 110. The sandbox tool 110 can be configured to cooperate with components of the secure OS 106 to create an isolated execution environment for accessing untrusted content without exposing other processes and resources of the user computing system 102 to the untrusted content. In particular, the sandbox tool 110 can be configured to allocate resources (storage space, memory, etc) of the user computing system 102, which are necessary to access the untrusted content, to the isolated execution environment, and apply security polices of the secure OS 106 to the isolated execution environment such that untrusted content running in the isolated execution environment can only access the resources allocated to the isolated execution environment. As such, the user can access the untrusted content without exposing the user computing system 102 to any possible malicious or dangerous content.
In embodiments, the untrusted content can be applications, programs, files, and/or data. The sandbox tool 110 can be configured to create the isolated execution environment to allow the applications, programs, files, and/or data to be accessed, executed, or viewed without exposing the user computing system 102 to any possible malicious or dangerous content. For example, the applications, programs, files, and/or data can only access the resources allocated to the isolated execution environment.
In embodiments, the sandbox tool 110 can be configured to create and maintain multiple isolated execution environments. For instance, a user can desire to access, execute, or view multiple pieces of untrusted content. In this instance, the sandbox tool 110 can be configured to access, execute, or view each piece of untrusted content in a separate isolated execution environment while maintaining the isolation of each isolated execution environment. Additionally, for example, multiple users can operate the user computing system 102, and each user can have different access level to the user computing system 102. In this example, the sandbox tool 110 can be configured to create and maintain isolated execution environments, simultaneously, for different users while maintaining the isolation of each isolated execution environment.
In embodiments, as illustrated, the sandbox tool 110 can be implemented as part of the secure OS 106. Likewise, the sandbox tool 110 can be implemented as a standalone application that communicates with the components of the secure OS 106. In either case, the sandbox tool 110 can be written in any type of known open-source or proprietary programming language, such as C, C++, JAVA, etc.
In embodiments, the user computing system 102 can store and execute the secure operating system 106 and sandbox tool 110. Additionally, one or more of the remote computing systems 104 can store and execute the secure operating system 106 and the sandbox tool 110. As such, the user computing system 102 can access the operating system 102 and the sandbox 110 stored on the one or more remote computing system 104 via the network 108 in order to access content using a client-server model.
FIGS. 2A and 2B illustrate an exemplary software environment 200 in accordance with various embodiments. It should be readily apparent to those of ordinary skill in the art that software environment 200 depicted in FIGS. 2A and 2B represent a generalized schematic illustration and that other components may be added or existing components may be removed or modified.
As shown in FIG. 2A, the software environment 200 can include the secure OS 106, such as SELinux or similar secure multi-tasking, multi-user operating system. A run-time environment (not shown) can be configured to execute on the secure OS 106. The run-time environment can provide a set of software that supports the access of content (e.g. applications, files, data, etc.). The run-time environment can also comprise an application program interface (“API”) 205 and a complementary API (not shown) within an application space 210. The API 205 can be configured to provide a set of routines that the application space 210 uses to request lower-level services performed by the secure OS 106. The secure OS 106 can include a kernel (not shown) and device drivers 215. The kernel can be configured to provide secure access to the underlying hardware of the user computing system 102 (e.g. processor, memory, storage, input/output devices, network devices, etc.) through the device drivers 215.
In embodiments, during operation, the secure OS 106 can be configured to create a user execution environment 220 in the application space 210. The user execution environment 220 allows users to interact with the user computing system 102 to access content such as run application and programs, view files, etc. The secure OS 106 can be configured to perform the necessary processes to establish the user execution environment 220 such as creating a virtual processes server (e.g. X-server) to support user interaction with the user execution environment 220, providing access to the devices drivers 215, allocating resources (e.g. user namespace such as home directory and temporary directory) to support the user execution environment 220, and the like. Likewise, the secure OS 106 can enforce security policies in the user execution environment 220 to allow/prevent access to underlying resources (network ports, file directories, memory, etc.) of the user computing system 102.
In embodiments, in order to provide access to untrusted content 225 without endangering the user computing system 102, the sandbox tool 110 can be configured to cooperate with components of a secure OS 106, to create an isolated execution environment 230 for accessing untrusted content 225 without exposing other processes such as the user execution environment 220 and resources of the user computing system 102 to the untrusted content 225. In particular, the sandbox tool 110 can be configured to allocate resources (storage space, memory, etc) of the user computing system 102, which are necessary to access the untrusted content 225, to the isolated execution environment 230, and apply security polices of the secure OS 106 to the isolated execution environment 230 such that untrusted content 225 running in the isolated execution environment 230 can only access the resources allocated to the isolated execution environment 230.
In embodiments, to create the isolated execution environment 230, the sandbox tool 110 can be configured to cooperate with the secure OS 106 to create a temporary namespace for the isolated execution environment 230 (e.g. temporary home directory and trap directory). The sandbox tool 110 can be configured to copy (or instruct the secure OS 106 to copy) the untrusted content 225 to the temporary namespace and can be configured to create an execution file in the temporary namespace for accessing the untrusted content 225, for example, initiating and executing applications to view data and files.
In embodiments, the sandbox tool 110 can be configured to cooperate with the secure OS 106 to isolate the isolated execution environment 230 from the user execution environment 220. For example, the sandbox tool 110 can instruct the secure OS 106 to unshare any other namespaces (e.g. the user name space of the user execution environment 220) with the temporary namespace and to mount the temporary namespace over any existing namespaces so that the processes of isolated execution environment 230 cannot access files and processes of any other namespace except the temporary namespace.
In embodiments, once the temporary namespace is created, the sandbox tool 110 can be configured to cooperate with the secure OS 106 to associate a security context of the secure OS 106 with the isolated execution environment 230. For example, the sandbox tool 110 can assign (or instruct the secure OS 106 to assign) a security label to the execution file and any other processes of the isolated execution environment 230. The security label can identify the security policies applied by the secure OS 106 to the isolated execution environment, thereby, defining the levels of access the untrusted content 225 and any other processes have to the resources of the user computing system 102 via the device drivers 215. Likewise, the secure OS 106 can utilize the security label to allow processes with a particular security label (i.e. processes of a particular isolated execution environment 230) to access only processes with the same particular security label (i.e. other processes of the particular isolated execution environment 230).
In embodiments, the sandbox tool 110 can be configured to cooperate with the secure OS 106 to start a new virtual process server, such as an X Server providing an X Windows interface, for the isolated execution environment 230. The new virtual process server can be configured to provide a user interface to the untrusted content 225 and other processes running in the isolated execution environment 230. The new virtual process server can run with other virtual process servers supported by the secure OS 106, such as the virtual process server supporting the user execution environment 220. The sandbox tool 110 can be configured to associate the security label of the isolated execution environment 230 with the new virtual process server. Accordingly, the secure OS 106 can be aware of the new virtual process server and any processes utilizing the new virtual process server, such as the untrusted content 225, can only access processes and resources allowed by the security context of the isolated execution environment 230.
In embodiments, once the isolated execution environment 230 is created, the sandbox tool 110 can initiate execution of the untrusted content 225 in the isolated execution environment 230. During execution, the secure OS 106 can apply the security policies associated with the security label of the isolated execution environment 230. For example, the secure OS 106 can allow the new virtual process server to only access the processes with the same security label, and to only access the resources, for example, limit and control access to the device drivers 215, associated with the security label assigned to the isolated execution environment 230. Once the untrusted content 220 is finished executing, the sandbox tool 110 can be configured to remove (or instruct the secure OS 106 to remove) all traces of the isolated execution environment 230 such as terminating the new process server and removing the temporary namespace.
In embodiments, the sandbox tool 110 can be configured to create and/or maintain one or more isolated execution environments, simultaneously. For example, as illustrated in FIG. 2B, the sandbox tool 110 can create and maintain a new isolated execution environment 235 for accessing, executing, and/or viewing other untrusted content, such as untrusted content 240. The new isolated execution environment 235 can be initiated at the request of the user of the user execution environment 220 or processes running in the user execution environment 220. Likewise, the computing system 102 can be supporting multiple users, and, as such, the application space 210 can include additional user execution environments, such as user execution environment 245. The new isolated execution environment 235 can be initiated at the request of the user of the user execution environment 245 or processes running in the user execution environment 245. While FIG. 2B illustrated two exemplary user execution environments, one skilled in the art will realize that the sandbox tool 110 can create any number of user execution environments. Likewise, while FIG. 2B illustrated two exemplary isolated execution environments, one skilled in the art will realize that the sandbox tool 110 can create any number of isolated execution environments.
The isolated execution environments 230 and 235 can have the same security context, for example, the same levels of access to the resources of the user computing system 102. In order to keep the isolated execution environments 230 and 235 isolated from each other, the sandbox tool 110 can be configured to assign (or instruct the secure OS 106 to assign) unique security labels to each of the isolated execution environments 230 and 235. As such, the sandbox tool 110 can create the isolated execution environments 230 and 235 which co-exist and have the same level of access, but remain isolated from each other.
In embodiments, the sandbox tool 110 can be configured to select the security labels so that the isolated execution environment 230 and 235 each have a unique security label that is different from security labels assigned to other isolated execution environments and other processes running on the user computing system 102. In order to ensure the security labels are unique, the sandbox tool 110, for each security label, can be configured to bind a communication socket in an “abstract name space” (not shown) of the secure OS 106 with a name that is the same as the security label.
In embodiments, the abstract name space defines a group of communication sockets that processes for the computing system 102 use to communicate. The abstract name space is independent of the file systems of the computing system 102, such as the files systems of the user execution environment 220 and 245. For example, if the secure OS 106 is a distribution of Linux, the abstract name space can include the communication sockets defined by the “Unix” command (e.g. “AF_UNIX”, “AF_LOCAL”). Because the abstract name space is independent of the file systems of the computing system 102, processes running in either the user execution environment 220 or 245 can see the communication sockets in the abstract name space.
In embodiments, to select a security label for either isolated execution environment 230 or 235, the sandbox tool 110 can be configured to select a security label, for example, randomly select a security label. Once selected, the sandbox tool 110 can be configured to (or instruct the secure OS 106 to) bind a communication socket in the abstract name space with a name that is the same as the selected security label. If the secure OS 106 returns an error that the name for the communication socket is already in use, the sandbox tool 110 can determine that the security label is already in use by another isolated execution environment or other process. As such, the sandbox tool 110 can be configured to select a different security label and attempt to bind a communication socket in the abstract name space with a name that is the same as the newly selected security label.
In embodiments, the sandbox tool 110 can be configured to select different security labels until a unique security label is determined, in other words, until the sandbox tool 110 successfully binds a communication socket with a name that is the same as the security label. Once an isolated execution environment ends, the sandbox tool 110 can be configured to (or instruct the secure OS 106 to) take down the bind associated with the security label of the isolated execution environment that is ending.
By binding a communication socket in the abstract name space, the sandbox tool 110 can reserve security labels for the isolated execution environments 230 and 235 and ensure that the isolated execution environments 230 and 235 have unique security labels. Additionally, because the sandbox tool 110 utilizes the abstract name space that is independent of the file systems, the sandbox tool 110 can assign unique security labels when the isolated execution environments 230 and 235 are initiated by different user execution environments 220 and 245 without collision.
FIG. 3 shows an exemplary block diagram of the secure OS 106 including the sandbox tool 110 according to various embodiments. It should be readily apparent to those of ordinary skill in the art that the secure OS 106 depicted in FIG. 3 represents a generalized schematic illustration and that other components may be added or existing components can be removed or modified. Likewise, while FIG. 3 illustrates the sandbox tool 110 as part of the secure OS 106, those of ordinary skill in the art will realize that the sandbox tool 110 can be implemented as a separate and standalone program or application that can communicate and cooperate with the secure OS 106, and the sandbox tool 110 can incorporate one or more of the components of the secure OS 106.
As shown in FIG. 3, the secure OS 106 can include a namespace module 305, a security module 310, a process server module 315. These components can be incorporated into the secure OS 106 and/or the sandbox tool 110 to implement the functionality of the isolated execution environment 230 as previously described and described in greater detail below.
In embodiments, the namespace module 305 can be configured generate and maintain the namespaces that support the user execution environments 220 and 245 and the isolated execution environments 230 and 235. More particularly, the namespace module 305 can create directories including a home directory (Homedir), file directory(/tmp) and /var/tmp for each of the user execution environments 220 and 245, and, when necessary, create a temporary home directory and tmp directory for each of the isolated execution environments 230 and 235. Likewise, the namespace module 305 can be configured to remove the namespace of each of the isolated execution environments 230 and 235 once the user computing system 102 has completed accessing the untrusted content 225 or 240. Additionally the namespace module 305 can be configured to bind communication sockets in the abstract name space as described above and below.
In embodiments, the security module 310 can be configured to maintain and enforce the security policies of the secure operating system 106. The security policies can define the various access levels of the processes running on the user computing system 102. For example, the security policies can define the various resources that are accessible at different access levels such as full or limited network access, full or limited memory access, full or limited storage access, and the like. To enforce the security policies, the security module 310 can be configured to apply a security context to different processes running on the user computing system 102 by assigning a security label, for example MCS label in SELinux, to different processes. The security label is associated with the secure OS 106 and can identify what security policies the security module 310 should apply to the processes running on the user computer system 102. When the processes, which are assigned a particular security label, request access to resources of the user computing system 102, the secure OS 106 can read the security label and apply the associated security policy to the processes, thereby restricting access of the processes to the security context. For example, the security module 310 can allow processes with a particular security label to only access the processes with the same security label, and to only access the resources, for example, limit and control access to the device drivers 215, defined by the security policies associated with the particular security label.
In embodiments, the process server module 315 can be configured to implement virtual processes servers for the processes running on the user computing system 102 such as the user execution environments 220 and 245 and the isolated execution environments 230 and 235. For example, if secure OS 106 is SELinux, the process server module 310 can be configured to implement one or more X Servers which provide X Windows interfaces that allow the user of the user computing system 102 to interact with the processes running on the user computing system 102.
In embodiments, the sandbox tool 110 can be configured to include the necessary logic, instructions, and commands to implement the methods and processes of creating the isolated execution environments 230 and 235 as described above and below. The sandbox tool 110 can be configured to cooperate with the secure OS 106 to create the execution environments 230 and 235 (e.g. creating/removing namespaces, isolating namespaces, copying content, applying security contexts, accessing the untrusted content 225 or 240, and the like).
In embodiments, the sandbox tool 110 can be configured to apply various security contexts to the isolated execution environments 230 and 235. For example, the sandbox tool 110 can define various security contexts for the isolated execution environments 230 and 235 from completely isolated (access to resources only necessary to access the untrusted content 225 or 240) to limited access (limited access to memory, network, storage, etc.). In the case of limited access, the sandbox tool 110 can be configured to apply security contexts that restrict access to a particular type of resource (e.g. network, memory, storage, processors) and/or that limits access to the different types of resources (e.g. certain network ports, certain memory ranges, certain storage location, certain processors). To apply the security context, the sandbox tool 110 can apply a security label to the isolated execution environments 230 and 235 and the processes of the isolated execution environments 230 and 235 and/or can instruct the security module 310 to apply a security label to the isolated execution environments 230 and 235 and the processes of the isolated execution environments 230 and 235. When applying the security context, the isolated execution environments 230 and 235 can have different levels of access.
In embodiments, the sandbox tool 110 can be configured to create and/or maintain one or more isolated execution environments, such as isolated execution environments 230 and 235, simultaneously. The multiple isolated execution environments 230 can have the same security context, for example, the same levels of access to the resources of the user computing system 102 or different. In order to keep the isolated execution environments 230 and 235 isolated from each other, the sandbox tool 110 can be configured to assign (or instruct the security module 310 to assign) unique security labels to each of the multiple isolated execution environments 230. For example, the sandbox tool 110 can be configured to (or instruct the security module 310 to) select a security label, for example, randomly select a security label. Then, the sandbox tool 110 can be configured to (or instruct the name space module 305 to) bind a communication socket in the abstract name space with a name that is the same as the selected security label, as described above. As such, the sandbox tool 110 can create the isolated execution environments 230 and 235 which co-exist and have the same or different level of access, but remain isolated from each other.
In embodiments, the sandbox tool 110 can be preconfigured with the security context to apply to the isolated execution environments 230 and 235. For example, the sandbox tool 110 can be preconfigured to apply a completely isolated context or limited access context to the isolated execution environments 230 and 235. Likewise, the sandbox tool 110 can be preconfigured to apply a security context based on the type of untrusted content 225 or 240 accessed in the isolated execution environments 230 and 235. For instance, the sandbox tool 110 can be preconfigured to apply a limited network access (e.g. access to only specific network ports) security context to any untrusted content that requires network access.
In embodiments, the sandbox tool 110 can be configured to allow the user to select the security context for the isolated execution environment 230. For example, the sandbox tool 110 can allow the user to select the preconfigured security context to apply to the isolated execution environment. Likewise, the sandbox tool 110 can allow the user to select the security context each time an isolated execution environment 230 or 235 is created. As such, the sandbox tool 110 can be configured to include the necessary logic, instructions, and commands to generate graphical user interfaces (GUIs) that allow a user select a security context to apply to the isolated execution environments 230 and 235.
In embodiments, in order to initiate access in the isolated execution environment 230, the sandbox tool 110 can be configured to allow a user to request the access of untrusted content 225 or 240 in an isolated execution environment 230 and/or 235. As such, the sandbox tool 110 can be configured to include the necessary logic, instructions, and commands to generate GUIs that allow a user to start the sandbox tool 110, select untrusted content 225 and/or to access in the isolated execution environment 230, and select a security context to apply to the isolated execution environment 230. For instance, the sandbox tool 110 can be directly accessed in order to initiate access of the untrusted content 225 in the isolated execution environment 230. Additionally, the sandbox tool 110 can be linked to other applications and programs (e.g. web browsers) to allow access of the untrusted content 225 in the isolated execution environment 230.
In embodiments, additionally, in order to initiate access in the isolated execution environment, the sandbox tool 110 can be configured to automatically initiate access of the untrusted content in the isolated execution environments 230 and/or 235. For example, upon the access of certain untrusted content, such as particular files or applications, the sandbox tool 110 can automatically initiate access of the untrusted content in the isolated execution environments 230 and/or 235. As such, the sandbox tool 110 can be configured to include the necessary logic, instructions, and commands to GUIs that allow selection of types of untrusted content 225 and/or 240 which will automatically be accessed in the isolated execution environments 230 and/or 240 and the security context to be applied to the isolated execution environment 230.
FIG. 4A depicts an exemplary flow diagram 400 for creating an isolated execution environment in accordance with various embodiments. It should be readily apparent to those of ordinary skill in the art that the flow diagram 400 depicted in FIG. 4A represents a generalized schematic illustration and that other stages can be added or existing stages can be removed or modified.
In 405, the processing can begin. In 410, the sandbox tool 110 can initiate access of the untrusted content in an isolated execution environment. The sandbox tool 110 can automatically initiate access of the untrusted content in the isolated execution environment 230. For example, upon the access of certain content, such as particular files or applications, the sandbox tool 110 can automatically initiate access of the untrusted content in the isolated execution environment 230.
Likewise, the sandbox tool 110 can initiate access of the untrusted content based on a request from the user of the user computing system 106. For example, the sandbox tool 110 can be configured to be accessed by the user and configured to allow the user to select the unfrosted content 225 to be accessed in the isolated execution environment 230. For instance, the sandbox tool 110 can be directly accessed in order to initiate access of the untrusted content 225 in the isolated execution environment 230. Additionally, the sandbox tool 110 can be linked to other applications and programs (e.g. web browsers) to allow access of the untrusted content 225 in the isolated execution environment 230.
In 415, the sandbox tool 110 can create a temporary namespace for the isolated execution environment 230. For example, the sandbox tool 110 can instruct the namespace module 305 to create a temporary namespace for the isolated execution environment 230, such as a temporary home directory and tmp directory. The namespace module 205 can create the temporary namespace to model the structure of the namespace of the user execution environment 220 and can label the temporary directories with a unique name such as “sandbox_x_file.t”.
In 420, the sandbox tool 110 can copy the untrusted content 225 to the temporary namespace for the isolated execution environment 230. For example, the sandbox tool 110 can copy or can instruct the secure OS 106 to copy the untrusted content 225 to the temporary home directory and tmp directory in the same location it would be found in the home directory and tmp directory of the user execution environment 220. In addition to copying the untrusted content 225, the sandbox tool 110 can copy any other necessary content (files, applications, programs) to the temporary namespace, which is required to access the untrusted content 225.
For example, if the untrusted content 225 is an untrusted file or data, the sandbox tool 110 can copy or can instruct the secure OS 106 to copy the untrusted file and/or data to the temporary home directory and tmp directory in the same location it would be found in the home directory and tmp directory of the user execution environment 220. Additionally, the sandbox tool 110 can copy or can instruct the secure OS 106 to copy any additional data, files and applications to the temporary home directory and tmp directory that are required to access the untrusted file and/or data.
In another example, if the untrusted content 225 is an untrusted program or application, the sandbox tool 110 can copy or can instruct the secure OS 106 to copy the untrusted program or application to the temporary home directory and tmp directory in the same location it would be found in the home directory and tmp directory of the user execution environment 220. Additionally, the sandbox tool 110 can copy or can instruct the secure OS 106 to copy any additional data, files and applications to the temporary home directory and tmp directory that are required to access and execute the untrusted program or application.
In 425, the sandbox tool 110 can create an execution file in the temporary namespace. The execution file can be configured to cause the untrusted content 225 to execute once the isolated execution environment 230 is completely created. For example, if the untrusted content 225 is an unfrosted program or application, the execution file can cause the untrusted program or application to begin execution. Likewise, if the untrusted content 225 is an untrusted file and/or data, the execution file can cause the appropriate applications or programs to begin execution in order to view and access the untrusted data and/or files.
In 430, the sandbox tool 110 can isolate the temporary namespace for other namespaces such as the namespace of the user execution environment 220. For example, the sandbox tool 110 can instruct the namespace module 305 to unshare the namespace of the user execution environment 220 to prevent access to processes in the user execution environment 220. Then, the sandbox tool 110 can instruct the namespace module 305 to mount the temporary namespace over the namespace of the user execution environment 220, thereby preventing any access by the untrusted content 225 to the user execution environment 220.
In 435, the sandbox tool 110 can set the security context of the isolated execution environment 230. For example, the sandbox tool 110 can apply or can instruct the security module 310 to apply a security label, which identifies the security policies, to the isolated execution environment 230. The security context can be predetermined for the particular untrusted content 225 and/or selected by the user of the computing system 102.
For example, if the secure OS 106 is SELinux, the sandbox tool 110 can apply or can instruct the security module 310 to apply a MCS label, such as “MCS1”, to the isolated execution environment. In embodiments, the sandbox tool 110 can be configured to create and/or maintain one or more isolated execution environments 230, simultaneously. The multiple isolated execution environments 230 can have the same security context, for example, the same levels of access to the resources of the user computing system 102. In the above example, in order to keep the multiple isolated execution environments 230 isolated from each other, the sandbox tool 110 can be configured to assign (or instruct the security module 310 to apply) different MCS labels, for example random MCS labels, to each of the multiple isolated execution environments 230. For instance, the sandbox tool 110 can assign other isolated execution environment 230 different MCS labels, such as “MCS2”, “MCS3”, etc. As such, the sandbox tool 110 can create one or more isolated execution environments 230 which co-exist and have the same level of access, but remain isolated from each other.
In 440, the sandbox tool 110 can create a new virtual process server for the isolated execution environment 230. For example, the sandbox tool 110 can instruct the process server module 315 to create a new virtual process server for the isolated execution environment 230. Because a security label has been applied to the isolated execution environment 230, the new virtual process server will run according to the attached security label, for example, “sandbox_xserver_t:MCS1”. In 445, the sandbox tool 110 can remove any data used to create the isolated execution environment 230.
In 450, the sandbox tool 110 can instruct the new virtual process server to automatically maximize user interfaces generated by the new virtual process server. For example, if the new virtual process server is an X Windows server, the sandbox tool 110 can instruct, directly or via the process server module 315, to maximize the X windows generated by the new X Server. Because a security label has been applied to the isolated execution environment 230, the windows manager of the new virtual process server will run according to the attached security label, for example, “sandbox_x_t:MCS1”.
In 455, the sandbox tool 110 can run the execution file for the untrusted content 225. As such, the untrusted content 225 will be accessed in the isolated execution environment. For example, if the untrusted content 225 is an untrusted program or application, running the execution file causes the untrusted program or application to begin execution. Likewise, if the untrusted content 225 is an untrusted file and/or data, running the execution file causes the appropriate applications or programs to begin execution in order to view and access the untrusted data and/or files. In these examples, once the untrusted applications, programs, and/or the appropriate application and programs to access the untrusted data and/or files begin execution, the new virtual process server generates user interfaces (e.g. X-Windows environment) to allow the user to interact with the application and programs.
Because a security label has been applied to the isolated execution environment 230, the untrusted content 225 and/or any other process will run according to the attached security label, for example, “sandbox_x_client_t:MCS1”. As such, the secure OS 106 will apply security policies and grant/restrict access to the resources of the user computing system 102 according to the attached security label. Likewise, the untrusted content 225 and any other process with the applied security label can only access processes with the same security label, “MCS1”.
In 460, the sandbox tool 110 can optionally track malicious activity from the untrusted content 225. The sandbox tool 110 can track or instruct the security module 310 to track malicious activity from the untrusted content 225. For example, the sandbox tool 110 and/or security module 310 can monitor for requests to access resources outside the security context of the isolated execution environment. The sandbox tool 110 and/or the security module 310 can store a record of the malicious activity and/or notify the user of the malicious activity. Because the malicious activity is outside the security context of the isolated execution environment, the secure OS 106 can prevent the malicious activity from gaining access to the resources and processes of the user computing system 102.
In 465, the sandbox tool 110 can remove the isolated execution environment 230 after completion of the access of the untrusted content 225. For instance, the sandbox tool 110 can begin removal of the isolated execution environment 230 once the untrusted applications, programs, and/or the appropriate application and programs to access the untrusted data arid/or files are closed. For example, to remove the isolated execution environment, the sandbox tool 110 can stop or instruct the processor server module 315 to stop the new virtual process server associated with the isolated execution environment 230. Likewise, the sandbox tool 110 can delete or instruct the namespace module 305 to delete the temporary namespace (e.g. delete the temporary home directory and tmp directory). Additionally, the sandbox tool 110 can mount or instruct the namespace 305 to mount the home directory and tmp directory of the user execution environment 220. In 470, the processing can end, repeat or return to any point.
FIG. 4B depicts an exemplary flow diagram 480 for selecting a unique security label for an isolated execution environment 235. The selecting of a unique security label can be utilized in creating any isolated execution environment, for example, during the setting of the security context, illustrated above in FIG. 4B. It should be readily apparent to those of ordinary skill in the art that the flow diagram 480 depicted in FIG. 4B represents a generalized schematic illustration and that other stages can be added or existing stages can be removed or modified.
In 482, the processing can begin. In 484, the sandbox tool 110 can select a security label for an isolated execution environment 235. For example, if the secure OS 106 is SELinux, the sandbox tool 110 may have (or instructed the security module 310) to select a MCS label, such as “MCS1”, for the isolated execution environment 230, and the sandbox tool 110 may have (or instructed the namespace module 305) to bind a communication socket to a name that is the same as “MCS1”. In this example, for isolated execution environment 235, the sandbox tool 110 can select (or instruct the security module 310 to select) a new MCS label for the isolated execution environment 235, such as “MCS2”.
When selecting the security label, the sandbox tool 110 can randomly select the security label. In the above example, the MCS label can include a part that takes the form “s0: Number 1, number 2” where “Number 1” and “Number 2” can be any number randomly selected between 0-1023 and “Number 2” is larger than “Number 1”. Accordingly, in the above example, “MCS1” could include the randomly selected part “s0: 0025, 0101”. Likewise, the sandbox tool 110 can randomly select “MCS2” to include the part “s0: 0075, 0085”.
In 486, the sandbox tool 110 can bind a communication socket in the abstract namespace to a name that is the same as the security label. For instance in the above example, the sandbox tool 110 can bind (or instruct the namespace module 305) to bind a communication socket in the abstract namespace to the name “MCS2” (e.g. “s0: 0075, 0085”), which is same as the security label for the isolated execution environment 235. In this example, the sandbox 110 can utilize a command such as “BIND” in Linux.
In 788, the sandbox tool 110 can determine if an error occurred in binding the communication socket. If a communication socket has already been bound to the selected security label, the secure OS 106 can return an error indicating that the name is invalid because it already exists. For instance, in the above example, the sandbox tool 110 randomly selected a security label “MCS2” which was different from the security label “MCS1”. As such, the sandbox tool 110 can bind a communication socket to the name “MCS2” without receiving an error that the name already exists.
If the sandbox tool 110 did receive an error in the binding, the sandbox tool 110 can randomly select a new security label and attempt to bind a communication socket in the abstract namespace. For instance, in the above example, if the sandbox tool 110 had randomly selected a previously selected security label, for example, “MCS1” (e.g. s0: 0025, 0101) for the isolated execution environment 235, the sandbox tool 110 would receive an error indicating that a communication socket with that name already exists (i.e. was bound to “MCS1” during the creation of the isolated execution environment 230). As such, the sandbox tool 110 can randomly select a new MCS label for the isolated execution environment 230 and attempt to bind a communication socket in the abstract namespace.
In 490, if no error occurs in the binding, the sandbox tool 110 can apply the security label to the isolated execution environment 235. Because the sandbox tool 110 binds a communication socket to each security label applied to each isolated execution environment, the sandbox tool 110 can ensure that security label for isolated execution environment 235 is unique and that no future isolated execution environments will be assigned the security label while the isolated execution environment exists. In 492, the processing can end, repeat or return to any point.
As mentioned above, the sandbox tool 110 can be accessed directly or via other programs in order to initiate access of content in the isolated execution environment 230. FIGS. 5A and 5B are exemplary screen shots of various methods and processes of initiating the sandbox tool 110, and resulting exemplary interface for the isolated execution environment 230. While FIGS. 5A and 5B describe exemplary screen shots with reference to isolated execution environment 230 and the user execution environment 220, one skilled in the art will realize that the methods and processes can be applied to any user execution environment and/or isolated execution environment.
As illustrated in FIG. 5A, the secure OS 106, running on the user computing system 102, can provide the user execution environment 505, such as an X Windows interfaces, that allows a user to nm applications and programs, view files and data, and communicate with the remote computing systems 104.
In one exemplary embodiment, a user can execute a program such as a web browser, in order to communicate with the remote computing systems 104. As illustrated, the user can access the web browser through an interface 510. The user can desire to access the untrusted content 225, such as an ADOBE pdf file “game.pdf”. Because the user may not know the source of the untrusted content 225, the user can desire to isolate the user computing system 102 for the untrusted content 225. In one exemplary embodiments, the sandbox tool 110 can be configured to generate a selection 520 in a menu 515 that allows the user to initiate the sandbox tool 110 in order to access the untrusted content 225 in the isolated execution environment 230. When the user selects the untrusted content 225, the menu 515 can be presented to the user, which allows the user to initiate the sandbox tool 110.
In another exemplary embodiment, in order to initiate the sandbox tool 110, the user can directly access the sandbox tool 110. As illustrated in FIG. 5A, the sandbox tool 110 can be configured to provide a icon or link 525 that causes the sandbox tool 110 to initiate. In order to initiate the sandbox tool 110, the user can select the icon or link 525. Once initiated, the sandbox tool 110 can provide GUIs that allow the user to select the untrusted content 225 to access in the isolated execution environment 230, and select a security context to apply to the isolated execution environment 230.
As illustrated in FIG. 5B, once the sandbox tool 110 has created the isolated execution environment 230 and the execution file is run, the new virtual process server can create a new interface 530 for displaying the interface 535 for the application (e.g. ADOBE READER) to access the untrusted content 225. As such, the user can access the untrusted content 225 in the isolated execution environment 230.
FIG. 6 illustrates an exemplary block diagram of a computing system 600 which can be implemented as user computing system 102 and/or the remote computing systems 104 according to various embodiments. The functions of the secure OS 106 and the sandbox tool 110 can be implemented in program code and executed by the computing system 600.
As shown in FIG. 6, the computing system 600 includes one or more processors, such as processor 602 that provide an execution platform for embodiments of the secure OS 106 and the sandbox tool 110. Commands and data from the processor 602 are communicated over a communication bus 604. The computing system 600 also includes a main memory 606, for example, one or more computer readable storage media such as a Random Access Memory (RAM), where the secure OS 106 and the sandbox module 110 can be executed during runtime, and a secondary memory 608. The secondary memory 608 includes, for example, one or more computer readable storage media such as a hard disk drive 610 and/or a removable storage drive 612, representing a floppy diskette drive, a magnetic tape drive, a compact disk drive, etc., where a copy of a computer application program embodiment for the secure OS 106 and the sandbox tool 110 can be stored. The removable storage drive 612 reads from and/or writes to a removable storage unit 614 in a well-known manner. A user can interface with the secure OS 106 and the sandbox tool 110 with a keyboard 616, a mouse 618, and a display 620. The display adapter 622 interfaces with the communication bus 604 and the display 620. The display adapter 622 also receives display data from the processor 602 and converts the display data into display commands for the display 620.
Certain embodiments may be performed as a computer application or program. The computer program may exist in a variety of forms both active and inactive. For example, the computer program can exist as software program(s) comprised of program instructions in source code, object code, executable code or other formats; firmware program(s); or hardware description language (HDL) files. Any of the above can be embodied on a computer readable medium, which include computer readable storage devices and media, and signals, in compressed or uncompressed form. Exemplary computer readable storage devices and media include conventional computer system RAM (random access memory), ROM (read-only memory), EPROM (erasable, programmable ROM), EEPROM (electrically erasable, programmable ROM), and magnetic or optical disks or tapes. Exemplary computer readable signals, whether modulated using a carrier or not, are signals that a computer system hosting or running the present teachings can be configured to access, including signals downloaded through the Internet or other networks. Concrete examples of the foregoing include distribution of executable software program(s) of the computer program on a CD-ROM or via Internet download. In a sense, the Internet itself, as an abstract entity, is a computer readable medium. The same is true of computer networks in general.
While the teachings has been described with reference to the exemplary embodiments thereof, those skilled in the art will be able to make various modifications to the described embodiments without departing from the true spirit and scope. The terms and descriptions used herein are set forth by way of illustration only and are not meant as limitations. In particular, although the method has been described by examples, the steps of the method may be performed in a different order than illustrated or simultaneously. Furthermore, to the extent that the terms “including”, “includes”, “having”, “has”, “with”, or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term “comprising.” As used herein, the term “one or more of” with respect to a listing of items such as, for example, A and B, means A alone, B alone, or A and B. Those skilled in the art will recognize that these and other variations are possible within the spirit and scope as defined in the following claims and their equivalents.

## Claims

1. A method comprising:
creating, by a processor, a first execution environment on a computing system to access untrusted content, wherein the first execution environment is isolated from a second execution environment running on the computing system, the second execution environment is isolated from the first execution environment, and wherein the first and the second execution environments are associated with a single security context to control access to resources of the computing system;
creating, after the first execution environment is created, a temporary namespace for the first execution environment, wherein the temporary namespace comprises one or more temporary directories;
copying the untrusted content to the temporary namespace for the first execution environment, wherein the untrusted content is accessed from the temporary namespace in the first execution environment;
selecting after the first execution environment is created, a first security label for the first execution environment, wherein the first security label identifies a first set of policies for granting limited access to the resources of the computing system;
selecting a second security label for the second execution environment, wherein the second security label identifies a second set of policies for granting the limited access to the resources of the computing system;
binding a first communication socket to a first abstract name space associated with an operating system of the computing system with a first name that matches the first security label;
binding a second communication socket to an additional abstract name space associated with the operating system of the computing system with a second name that matches the second security label;
assigning the first security label to the first execution environment;
assigning the second security label to the second execution environment; and
upon completion of access of the untrusted content in the first execution environment, removing the first execution environment by deleting the temporary namespace for the first execution environment.

2. The method of claim 1, further comprising:
receiving an indication from the operating system that the first communication socket was previously bound with the first security label;
selecting a new security label for the first execution environment;
binding an additional communication socket with the new security label within the first abstract name space associated with the operating system; and
assigning the new security label to the first execution environment.

3. The method of claim 1, further comprising:
unbinding the first communication socket from the first security label after access of the untrusted content.

4. The method of claim 1, wherein selecting the first security label comprises randomly selecting the first security label.

5. The method of claim 1, further comprising:
receiving a selection of the identified first set of policies to apply to the first execution environment.

6. The method of claim 1, wherein creating the first execution environment comprises:
receiving a request to access the untrusted content in the first execution environment.

7. The method of claim 1, wherein the untrusted content comprises at least one of an application or a file.

8. A non-transitory computer readable storage medium comprising instructions to cause a processor to:
create, by the processor, a first execution environment on a computing system to access untrusted content, wherein the first execution environment is isolated from a second execution environment running on the computing system, the second execution environment is isolated from the first execution environment, and wherein the first and the second execution environments are associated with a single security context to control access to resources of the computing system;
create, after the first execution environment is created, a temporary namespace for the first execution environment, wherein the temporary namespace comprises one or more temporary directories;
copy the untrusted content to the temporary namespace for the first execution environment, wherein the untrusted content is accessed from the temporary namespace in the first execution environment;
select, by the processor, after the first execution environment is created, a first security label for the first execution environment, wherein the first security label identifies a first set of policies for granting limited access to the resources of the computing system;
select, by the processor, a second security label for the second execution environment, wherein the second security label identifies a second set of policies for granting the limited access to the resources of the computing system;
bind a first communication socket to a first abstract name space associated with an operating system of the computing system with a first name that matches the first security label;
bind a second communication socket to an additional abstract name space associated with the operating system of the computing system with a second name that matches the second security label;
assign the first security label to the first execution environment;
assign the second security label to the second execution environment; and
upon completion of access of the untrusted content in the first execution environment, remove the first execution environment by deleting the temporary namespace for the first execution environment.

9. The non-transitory computer readable storage medium of claim 8, further comprising instructions to cause the processor to:
receive an indication from the operating system that the first communication socket was previously bound with the first security label;
select a new security label for the first execution environment;
bind an additional communication socket with the new security label within the first abstract name space associated with the operating system; and
assign the new security label to the first execution environment.

10. The non-transitory computer readable storage medium of claim 8, further comprising instructions to cause the processor to:
unbind the communication socket from the first security label after access of the untrusted content.

11. The non-transitory computer readable storage medium of claim 8, wherein the instructions to cause the processor to select the first security label further comprise instructions to cause the processor to randomly select the first security label.

12. The non-transitory computer readable storage medium of claim 8, further comprising instructions to cause the processor to:
receive a selection of the identified first set of policies to apply to the first execution environment.

13. The non-transitory computer readable storage medium of claim 8, wherein the instructions to cause the processor to create the first execution environment further comprise instructions to cause the processor to receive a request to access the untrusted content in the first execution environment.

14. The non-transitory computer readable storage medium of claim 8, wherein the untrusted content comprises at least one of an application or a file.

15. A method comprising:
creating, by a processor, a first execution environment on a computing system to access untrusted content, wherein the first execution environment is isolated from a second execution environment running on the computing system, the second execution environment is isolated from the first execution environment, and wherein the first and the second execution environments are associated with a single security context to control access to resources of the computing system;
creating, after the first execution environment is created, a temporary namespace for the first execution environment, wherein the temporary namespace comprises one or more temporary directories;
copying the untrusted content to the temporary namespace for the first execution environment, wherein the untrusted content is accessed from the temporary namespace in the first execution environment;
selecting after the first execution environment is created, a first security label for the first execution environment, wherein the first security label identifies a first set of policies for granting limited access to the resources of the computing system;
selecting a second security label for the second execution environment, wherein the second security label identifies a second set of policies for granting the limited access to the resources of the computing system;
instructing an operating system of the computing system to bind a first communication socket to a first abstract name space associated with the operating system with a first name that matches the first security label;
instructing the operating system of the computing system to bind a second communication socket to an additional abstract name space associated with the operating system with a second name that matches the second security label;
assigning the first security label to the first execution environment;
assigning the second security label to the second execution environment; and
upon completion of access of the untrusted content in the first execution environment, removing the first execution environment by deleting the temporary namespace for the first execution environment.

16. The method of claim 15, further comprising:
receiving an indication from the operating system that the first communication socket was previously bound with the first security label;
selecting a new security label for the first execution environment;
instructing the operating system to bind an additional communication socket with the new security label within the first abstract name space associated with the operating system; and
assigning the new security label to the first execution environment.

17. The method of claim 15, further comprising:
instructing the operating system to unbind the first communication socket from the first security label after access of the untrusted content.

18. The method of claim 15, wherein selecting the first security label comprises randomly selecting the first security label.