| 1 | PRCHES0 ;WISC/RHD/AKS-ESIG MAINTENANCE ROUTINE ; 05/15/93  1:30 PM | 
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| 2 | V ;;5.1;IFCAP;;Oct 20, 2000 | 
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| 3 | ;Per VHA Directive 10-93-142, this routine should not be modified. | 
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| 4 | ;ROUTINE FOR MAINTAINING SUBFIELD 3 (ELECTRONIC SIGNATURE) | 
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| 5 | ; FIELD .05 (2237 REFERENCE NUMBER), FILE 442 | 
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| 6 | DECODE(LEVEL0,LEVEL1) ;Extrinsic Function to return hashed electronic sig to readable form. | 
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| 7 | ;returns "" if unsuccessful | 
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| 8 | NEW RECORD,VERSION,PERSON,SIG,CHECKSUM | 
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| 9 | ;get record and check version | 
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| 10 | S RECORD=$G(^PRC(442,LEVEL0,13,LEVEL1,0)) I RECORD="" Q "" | 
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| 11 | S VERSION=$P(RECORD,"^",14) | 
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| 12 | S PERSON=+$P(RECORD,"^",2) | 
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| 13 | I VERSION'="",VERSION'=1 Q "" | 
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| 14 | S SIG=$P(RECORD,"^",3) | 
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| 15 | D1 ;decode e signature for version 1 | 
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| 16 | S CHECKSUM=$$SUM^PRCUESIG(LEVEL0_"^"_LEVEL1_"^"_$$STRING(RECORD)) | 
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| 17 | Q $$DECODE^PRCUESIG(SIG,PERSON,CHECKSUM) | 
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| 18 | ENCODE(LEVEL0,LEVEL1,USERNUM,Y) ;usage:D ENCODE^PRCHES0(...) | 
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| 19 | ;Encode esig for version 1 only | 
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| 20 | NEW RECORD,SIGBLOCK,CHECKSUM,OLDUSER | 
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| 21 | ;get record | 
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| 22 | S USERNUM=+USERNUM | 
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| 23 | I USERNUM=0 S Y=-3 Q  ;-3 no user number | 
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| 24 | S SIGBLOCK=$P($G(^VA(200,USERNUM,20)),"^",2) | 
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| 25 | I SIGBLOCK="" S Y=-2 Q  ;-2 = no sig block in file 200 | 
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| 26 | S RECORD=$G(^PRC(442,LEVEL0,13,LEVEL1,0)) | 
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| 27 | I RECORD="" S Y=-1 Q  ;-1 no record | 
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| 28 | I $P(RECORD,"^",3)'="" S Y=-4 Q  ;-4 cannot re-sign record | 
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| 29 | S OLDUSER=+$P(RECORD,"^",2) | 
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| 30 | I OLDUSER=0 S $P(RECORD,"^",2)=USERNUM | 
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| 31 | I OLDUSER>0 S USERNUM=OLDUSER | 
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| 32 | S:$P(RECORD,"^",4)="" $P(RECORD,"^",4)=$$NOW^PRCUESIG | 
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| 33 | S CHECKSUM=$$SUM^PRCUESIG(LEVEL0_"^"_LEVEL1_"^"_$$STRING(RECORD)) | 
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| 34 | S $P(RECORD,"^",3)=$$ENCODE^PRCUESIG(SIGBLOCK,USERNUM,CHECKSUM) | 
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| 35 | S $P(RECORD,"^",13,14)=$$SUM^PRCUESIG(SIGBLOCK)_"^"_1 | 
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| 36 | S ^PRC(442,LEVEL0,13,LEVEL1,0)=RECORD | 
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| 37 | S Y=1 Q | 
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| 38 | REMOVE(LEVEL0,LEVEL1) ;Entry Point to remove esig | 
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| 39 | NEW I,RECORD | 
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| 40 | S RECORD=$G(^PRC(442,LEVEL0,13,LEVEL1,0)) I RECORD="" Q | 
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| 41 | F I=2,3,4,13 S $P(RECORD,"^",I)="" | 
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| 42 | S ^PRC(442,LEVEL0,13,LEVEL1,0)=RECORD | 
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| 43 | Q | 
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| 44 | VERIFY(LEVEL0,LEVEL1)      ;extrinsic function to verify esig  Returns 1 if valid, 0 if not valid | 
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| 45 | NEW RECORD,VERSION,SIGBLOCK | 
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| 46 | S RECORD=$G(^PRC(442,LEVEL0,13,LEVEL1,0)) | 
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| 47 | S VERSION=$P(RECORD,"^",14),SIGBLOCK=$P(RECORD,"^",13) | 
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| 48 | I VERSION_SIGBLOCK="" Q 1 | 
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| 49 | Q $$SUM^PRCUESIG($$DECODE(LEVEL0,LEVEL1))=SIGBLOCK | 
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| 50 | STRING(X)          ;Build String of critical fields | 
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| 51 | Q $P(X,"^")_"^"_$P(X,"^",4)_"^"_$P(X,"^",9) | 
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