Digital signaturing method and system for re-creating specialized native files out of a container imported from an open network or residing on a CD-ROM

• US 6,353,887 B1
• Filed: 11/13/1998
• Issued: 03/05/2002
• Est. Priority Date: 11/13/1998
• Status: Expired due to Term

• Current Assignee: Unisys Corporation
• Original Assignee: Unisys Corporation
• Inventors: Frankel, Edward Henry, Cotugno, Lauren Ann, Pham, Thien Huu
• Primary Examiner(s): Peeso, Thomas R.
• Application Number:
  US09/191,880
• Time in Patent Office: 1,208 Days
• Field of Search: 713/165, 713/166, 713/168, 713/200, 713/201
• US Class Current: 713/165
• CPC Class Codes: G06F 21/6236 between heterogeneous systems

Abstract

A method and system is provided whereby after specialized original native format data files have been signatured and “wrapped” along with a directory into an industry standard byte stream container file for transmission over the Internet (or for use of other computer platforms), then subsequently, the container of wrapped files with its signature can be accessed by a proprietary computer platform which will then use the signature to verify the integrity of the files and will unwrap or re-create these files back into the original specialized native format for use by the proprietary computer platform.

Claims

1. A method for verifying and unwrapping a signatured wrapped container file comprising the steps of:

(a) establishing a DSA KEYSFILE which holds parameters of KeyID, SSR, P, Q, G and a system public key;

(b) establishing signatured words R and S for the container file which is wrapped and exists as an industry-standard byte stream text format file;

(c) utilizing an Unwrap operation which accesses said parameters of said DSA FILE and which accesses said signatured container file with said R and S words;

(d) executing an Unwrap operation to the parameters and signatured container file in order to restore files in the reconstituted specialized original native file format.

2. In a network having a first computer platform which utilizes specialized original native format file and a second platform which uses an industry-standard byte stream text data format container file with digital signature, as a standard file, a method for converting and reconstituting said industry-standard byte stream text container data file into specialized original native format files which are unwrapped and useable by said first computer platform comprising the steps of:

(a) accessing said industry-standard byte stream container data file with digital signature from an open network by transmission to said second platform;

(b) storing, by said second platform of said accessed industry-standard byte stream container data file and signature;

(c) receiving and processing by said first platform of said byte stream container data file (wrapped file) including;

(c1) verifying the signature of said wrapped container data file in order to validate the integrity of the transmitted file;

(c2) processing said wrapped byte stream container data file by said first computer platform using its own operating system and programs to convert said wrapped industry-standard byte stream container data file into unwrapped specialized original native files;

(d) placing said unwrapped files after verification onto a storage medium usable by said first computer platform.

3. The method of claim 2 wherein step (c1) includes the step of:

(c1a) calling a first program routine (MCP_FILEWRAPPER) which utilizes a special verification routine (DSAVERIFY) from a Signature Support Library to validate the integrity of the transmitted byte stream container data file.

4. The method of claim 2 wherein step (c2) includes the step of:

(c2a) executing a second program routine (MCP_WRAPPER), after signature verification, to convert (unwrap) said byte stream container data file into said original specialized native data files.

5. In a computer platform operating on a specialized original native format container data file, a method for converting an industry-standard byte stream data container file with signature back to said original specialized native format data files comprising the steps of:

(a) initiating an unwrap operation on said byte stream container data file with digital signature including entering a public key by a user;

(b) executing a MCP_FILEWRAPPER routine to verify the user specified public key and to verify the container file'"'"'s signature;

(c) calling a MCP_WRAPPER program to unwrap the verified container file in order to reconstitute the accessed byte stream signature and data files within the container into the original specialized native format data files.

6. The method of claim 5 wherein step (b) for signature verification includes the steps of:

(bi) checking for validity of the wrapped container file;

(bii) checking to see the container file has a digital signature;

(biii) calling a Signature Support Library to use a verification routine which then reads the digital signature;

(biv) verifying that the signature is the proper value.

7. The method of claim 6 where step (biii) includes the steps of:

(a) obtaining the System Software Release (SSR) level of the wrapped container file;

(b) calling the routine GET_DSA_PQGKEY in order to obtain the prime numbers P,Q,G and the system public key which is based on the System Software Release (SSR) level;

(c) reading the data from the signed wrapped container file to a local buffer and calling the program DSAVERIFY to verify signature words (R,S) where R and S are a series of digital words.

8. In a computer platform utilizing a Signature Support Library, and operating on a specialized original native format container data file and disk File Header (DFH), a system for receiving and utilizing an industry-standard byte stream data files having a digital signature in order to decode and reconstitute said byte stream container data file into said specialized original native format container data file after execution of a signature integrity verification program, said system comprising:

(a) means for accessing said industry-standard byte stream container data file and signature;

(b) means to verify said digital signature portion of said reconstituted byte stream container file in order to verify the integrity of said container file;

(c) program means to reconvert said accessed byte stream container data file into resultant files of said specialized original native files after signature verification;

(d) means to place said resultant verified files on a storage medium for use by said computer platform.

9. The system of claim 8 wherein said means to verify said digital signature includes:

(a) first program means (MCP_FILEWRAPPER) to access said Signature Support Library;

(b) said Signature Support Library for calling a verification routine (DSAVERIFY) which validates said signature;

(c) second program means (MCP_WRAPPER) for converting, after signature verification, said byte steam container data file into verified specialized original native files.

10. In a first computer platform operating on a specialized original native formatted files, a system for verifying and unwrapping a wrapped byte stream container data file into said original specialized native formatted files, comprising:

(a) means to access a signatured byte stream text container data file;

(b) means to access a Digital Signal Algorithm (DSA) Keysfile holding a set of specialized parameters and system public key;

(c) means to combine said DSA Keysfile with said signatured byte stream text container data file to verify said container data file'"'"'s integrity;

(d) means to execute an Unwrap operation on said verified container data file in order to reconstruct said specialized original native files after verification of said signature.

11. The system of claim 10 where said set of specialized parameters include:

(i) a KEYID;

(ii) a System Software Release level (SSR);

(iii) a random group of prime numbers designated P,Q,G.

12. A method for verifying and unwrapping a signatured wrapped container file comprising the steps of:

(a) initiating by a user of a Work Flow Language (WFL) Unwrap statement with digital signature for a container including passing a public key to a signature support library;

(b) parsing the unwrap statement command via a Work Flow Language compiler and instructing the Master Control Program Operating System to initiate the procedure MCP_FILEWRAPPER;

(c) executing the procedure MCP_FILEWRAPPER on a file list containing input container names and the file names to be unwrapped out of these containers and utilizing the public key which was passed to said Operating System;

(d) verifying the user-specified public keys;

(e) identifying a container name and opening the container to verify its validity;

(f) unwrapping a file name and/or a directory name for unwrapping out of the container;

(g) checking each directory name to see if the user is privileged to access it;

(h) sorting and checking to see if a particular container'"'"'s directory contains the specified file name or names that match the specified directory;

(i) adding to the internal processing list any matched file names which are found in the container'"'"'s directory;

(j) closing the container file.

13. The method of claim 12 wherein step (e) “

Got a Container Name?”

includes the steps of;

(i) calling the EXTRACTLIST program for processing if there is no container name, but there is something in the internal processing list;

(ii) executing the EXTRACTLIST program in order to;

(c1) get the next container name from the internal processing list;

(c2) open the container file and calling the SIGNATURE_VERIFIED logic to verify the container'"'"'s digital signature;

(c3) check to see that the container'"'"'s signature is verified;

(c4) check to see if there is a file name in the internal processing list to be unwrapped for this container;

(c5) get the file'"'"'s name for unwrapping, getting its address in the container file and its new destination file name;

(c6) positioning the container'"'"'s file pointer to the beginning of the file to be unwrapped as indicated by the file'"'"'s address;

(c7) executing the procedure MCP_WRAPPER in order to unwrap the passing file and giving it its new destination file name.

14. The method of claim 13 wherein step (c2) of the SIGNATURE_VERIFIED logic includes the steps of:

(a) initiating the signature verified logic;

(b) checking if the container supports a digital signature;

(c) seeing that the file has a digital signature;

(d) communicate with the signature support library to use its DSA Verify routine;

(e) read data from the wrapped file into a local buffer;

(f) read the R &

S signatures;

(g) call the DSA verify routine by passing the parameters P,Q,G,R,S and the public key;

(h) validating the signature as a good digital signature.

15. The method of claim 13 wherein step C7 on executing the MCP_WRAPPER procedure includes the steps of:

(a) initiating an unwrap action and checking for the input wrapped file'"'"'s validity;

(b) determining whether the wrapped file is signatured and there are no further calls by the MCP_FILEWRAPPER to the MCP_WRAPPER;

(c) exiting from the MCP_WRAPPER procedure.