International Business Machines Corporation

Symantec Corporation

Todd A Smith

Donavon W Johnson

Stephen P Morgan

Amal A Shaheen-Gouda

Larry W Henson

Grover Herbert Neuman

Larry K Loucks

Charles H Sauer

Albert Y Chang

Charles Andrew Payne

John C O'Quin, Iii

Keith E Duvall

Michael Anthony Alagna

Anthony D Hooten

Luca Loiodice

In a first embodiment, an information handling system determines whether a resource is likely misrepresented as a trusted resource within a global computer network. In a second embodiment, the information handling system outputs an indication of whether a resource within a global computer network is recognized as a known trusted resource.

Method, system, and computer program product for security within a global computer network

The system and method of this invention authorizes a process running at a client data processing system to have access to a service at a server data processing system. The data processing systems are connected by a communication link in a distributed processing environment. A set of credentials for the process are created at the server in response to a message from the client requesting a service. The server returns a credentials id identifying the created set of credentials to the client process. The client uses this returned id in subsequent requests and is authorized access as controlled by the set of credentials identified by the returned id in the subsequent request. The server can deny access to the service by the process if the id returned in a subsequent request is determined by the server not to identify the set of credentials. The server denies the access if the server requires an authentication of the process.

Remote authentication and authorization in a distributed data processing

A distributed data processing system and method in which locks on a file are supported by a data structure that resides on either a client machine or on the file's server. When only a single client's processes are locking a file, the data structure can reside on that client. Whenever a plurality of client machines attempt to place locks on a file, the data structure is moved to the server; this forces the clients locking the file to communicate with the server when performing lock operations. When a client requests a lock from the server that cannot be granted because of an existing blocking lock, the client is informed that it should put the requesting process asleep awaiting a retry notification. When there is a change in the locks on the file that might allow such a client's now sleeping process to acquire the lock, the server sends a retry notice to the client. This awakens the sleeping process at the client, and the process then reattempts the lock operation by sending a message to the server.

File lock management in a distributed data processing system

In a distributed data processing system, the authentication of a process at one node for the use of a service at another node is performed in a facility that is separate from the requestor and service process. The separate facility is also replaceable, thereby allowing different authentication policies to be implemented within the distributed data processing system. The requesting process and the service process merely pass the authentication information between themselves without attempting to interpret the work of the separate authentication facility. In addition to authenticating the requestor to the service, the service is also authenticated to the requestor.

Flexible interface to authentication services in a distributed data

The system and method of this invention controls how client data processing systems in a distributed networking environment can efficiently extend files and write into regions of the files previously unoccupied by data. The server data processing system manages the distributed allocation of new file blocks by sending nascent zeros in addition to real bytes that have been requested by the client data processing system. Nascent zeros are logically zero bytes that have never been stored to or written to, and may be outside the current extent of the file. The server determines whether or not this additional range of nascent zeros will be sent to a client depending upon the amount of physical storage available at the server, and whether or not other client data processing systems require access to this range of blocks. Likewise, the client data processing system has the option of writing to this additional range of nascent zeros. By writing to the additional range of nascent zeros, a client data processing system can minimize the network traffic overhead used in sending messages to the server data processing system requesting a range of bytes.

File extension by clients in a distributed data processing system

A conventional single node operating system is provided with a distributed file management system (DFS) with a plurality of nodes and a plurality of files. The DFS uses the UNIX operating system tree structure employing inodes (data structure containing administrative information for each file) to manage the local files and surrogate inodes (s.sub.-- inode) to manage access to files existing on another node. In addition, the DFS uses a lock table to manage the lock status of files. The method which implements the DFS locking of records and files involves the following steps. If the file is a local file, then the UNIX operating system standard file locking is used. However, if a remote file is to be locked, the UNIX operating system LOCKF and FCNTL system calls are intercepted and an remote process call (RPC) DFS.sub.-- LOCK.sub.-- CONTROL is executed. The server node receives the remote process call and carries out the lock request. The request could entail locking a single record, a set of records or the whole file. The server then acknowledges receipt of the RPC by sending a signal while the client surrogate inode is waiting for a reply from the DFS.sub.-- LOCK.sub.-- CONTROL RPC. The client confirms the reception of the lock and sends an acknowledgement to the remote server. The server updates the lock table after receiving the acknowledgement from the client surrogate inode. If the server does not confirm the reception of DFS.sub.-- LOCK.sub.-- CONTROL's acknowledgement, then DFS.sub.-- LOCK.sub.-- CONTROL updates the lock table.

System for file and record locking between nodes in a distributed data

A distributed file management system (DFS) with a plurality of nodes and a plurality of files is disclosed. The DFS uses the UNIX operating system tree structure employing inodes (data structures containing the administrative information of each file) to manage the local files and surrogate inodes (s.sub.-- inode) to manage access to files existing on another node. In addition, the DFS uses a file access structure lock (fas.sub.-- lock) to manage multiple requests to a single file. The primary reason for the addition of the fas.sub.-- lock for each file is to avoid the problem of deadlocks. The inodes and s.sub.-- inodes use the fas.sub.-- lock to synchronize their accesses to a file and avoid a deadlock situation where both s.sub.-- inode and inode await the use of a file that is locked by the other.

Distributed file access structure lock

A system and method in which client access to data at a server is synchronized to keep the data consistent by ensuring that each portion of the data accessible for modification at a node is not accessible for reading or modification by any other node, while allowing portions of the data accessible only for reading to be accessible by any number of nodes. If a conflicting request arises from a different client the server must revoke data that has been previously distributed to a client. For a revoke.sub.-- bytes request, all outstanding get.sub.-- bytes are marked so that the bytes that are being requested to be revoked will be discarded when they do arrive at the client. To insure that read and write system calls on a file are performed in a serializable fashion throughout a distributed environment, each machine at which a read is being performed must acquire a read token and each machine at which a write is being performed must acquire a read/write token from the server for the file. When any machine has a read/write token, no machine is allowed to have a read token, although any number of machines may have a read token at the same time. The server coordinates the distribution of these tokens by revoking all read tokens whenever a write token is requested and revoking the write token whenever any read token is requested.

System and method for controlling client machine access to a portion of

An improved directory caching technique is provided for a plurality of data processing systems which are connected together in a network. In the system, when a local, or client, data processing system interrogates a remote, or server, data processing system for a unit of directory information, the server system is enabled to automatically send additional units of pertinent director information back to the client system in response to a subsequent change in the directory structure of the server system. If the server system is unable to continue updating the client system, for any of a plurality of possible reasons, the server system informs the client system of this fact, which enables the client system to purge itself of the formerly stored directory cache entry relative to this path, since the client system can no longer consider this cached path information to be currently correct.

Directory cache management in a distributed data processing system

The system and method of this invention maintains the latest file attributes such as file size, modify time, and access time, at the server data processing system in a distributed data processing system. The server data processing system combines information requested from the client data processing system that has permission to write to the file with information periodically received from other client data processing systems that may be extending the same file by mapping the file into their own virtual address space. In this way, the server can maintain the latest file size attribute even when some clients are extending the file through system calls and other clients are extending the file through mapped access. To maintain a latest modify time and access time, the server keeps a modify count and access count. The client data processing systems periodically send to the server data processing the modify count and access count that have been incremented whenever the client data processing system modifies and accesses the file. The server data processing system compares the counts at the server with the counts received from the clients to determine a latest corresponding modify time and access time.

Maintenance of file attributes in a distributed data processing system

Encryption and decryption mechanisms at transmitters and receivers, respectively, have applied thereto encryption or decryption keys and initializing values. These mechanisms generate cryptographic bit streams which are intermediate streams of generated values. These intermediate streams, generated prior to their real time need in the encryption or decryption processes, are stored in buffers until data is presented for encryption or decryption, at which time the cryptographic bit streams are conveyed from the buffers to mathematical functions, for combination with the data. This avoids the delays associated with the real time generation of the cryptographic bit streams during the encryption and decryption processes. Appropriate synchronization of the generation and buffer storage of the cryptographic bit streams at the transmitter and receiver is provided.

Buffered encryption/decryption

These master system files define the system characteristics that a user at any node in the system can expect to have. The master system files are mounted remotely from each of the nodes of the system and a local copy of the master system files is kept locally reflecting the current contents of the master system file. If a master system file is not available, the local copy is used in read only mode until the node containing the master is available. In addition, each user has its own file tree organization that dictates the necessary remote mounts of directories to enable a user logged on to any node to have the same view of the system that would be obtained from any other node in the system by that user.

Single system image uniquely defining an environment for each user in a

In a distributed environment several data processing systems are interconnected across a network system. A distributed services program installed on the systems in the network allows the processors to access data files distributed across the various nodes of the network without regard to the location of the data file in the network. The processing system accessing file, referred to as the client processing system, utilizes a client cache within its operating system to store the data file. Utilizing the client cache minimizes the number of reads and writes that must go over the network to the server processing system where the file physically resides. The system and method of this invention prevents a process in the client processing system from accessing data in the client cache that has been modified at another node in the network. The blocks of data in the client cache are tested for validity in the client processing system by using modification times as measured by the server processing system. If the cache data blocks are determined to be valid, the data blocks are determined to be invalid, the data blocks are discarded, and the file is accessed from the server processing system.

System and method for using cached data at a local node after re-opening

A distrbuted services program installed on each of a plurality of data processing systems in a network allows the processors to access data files distrbuted across the various nodes of the network. To reduce the network traffic overhead when files at other nodes are accessed, and to preserve the file system semantics, i.e. the file integrity, the accessing of the various files are managed by file synchronization modes. A file is given a first synchronization mode if a file is open at only one node for either read or write access. A file is given a second synchronization mode if a file is opened for read only access at any node. A file is given a third synchronization mode if the file is open for read access in more than one node, and at least one node has the file open for write access. If a file is in either the first or second synchronization mode, the client node, which is the node accessing the file, uses a client cache within its operating system store the file. All read and writes are then sent to this cache. If a file is in the third mode, all read and write requests must go to the server node where the file resides. The node accessing the file does not use the cache in its operating system to access the file data during this third mode.

Growing community of inventors

Austin, TX, United States of America

Todd A Smith