OpenCores
URL https://opencores.org/ocsvn/xgate/xgate/trunk

Subversion Repositories xgate

Compare Revisions

  • This comparison shows the changes necessary to convert path 
    /xgate
    from Rev 80 to Rev 81
    ↔ Reverse comparison
  •

Rev 80 → Rev 81

/trunk/sw/tools/HSW12ASM/README.txt
1,10 → 1,11
// 45678901234567890123456789012345678901234567890123456789012345678901234567890
Sept 1, 2009
August 10, 2010
 
The hsw12asm assembler was used to create the object code srecord files for
the test cases. This assembler is written in Perl so it should be usable on
most computer systems. I don't plan on trying a copy as part of this project
but please see to sites below for the most recent versions to download.
most computer systems. I don't plan on tieing a specific copy or version to
this project but please see the sites below for the most recent version
to download and use.
 
Documentation:
http://home.arcor.de/hotwolf/hsw12asm.html
/trunk/sw/applications/skipjack-1.01/skipjack.s
0,0 → 1,491
; 345678901234567890123456789012345678901234567890123456789012345678901234567890
; Copyright (c) 2010, Robert Hayes
; SKIPJACK ENCRYPT/DECRYPT for xgate RISC processor core
; Bob Hayes - August 7, 2010
; Version 0.1 Basic SKIPJACK Encrypt and Decrypt modules for the Xgate
; processor. These routines do the basic codebook encrypt and decrypt
; functions, other modes of use such as output feedback,cipher feedback and
; cipher block chaining can be added at the host code level or the routines
; could be expanded to incorporate the required functionality.
 
; This implementation is believed to be compliant with the SKIPJACK algorithm
; as described in "SKIPJACK and KEA Algorithm Specifications" Version 2.0
; dated 29 May 1998, which is available from the National Institute for
; Standards and Technology:
; http://csrc.nist.gov/groups/STM/cavp/documents/skipjack/skipjack.pdf
 
;
; This source file is free software: you can redistribute it and/or modify
; it under the terms of the GNU Lesser General Public License as published
; by the Free Software Foundation, either version 3 of the License, or
; (at your option) any later version.
;
; Supplemental terms.
; * Redistributions of source code must retain the above copyright
; notice, this list of conditions and the following disclaimer.
; * Neither the name of the <organization> nor the
; names of its contributors may be used to endorse or promote products
; derived from this software without specific prior written permission.
;
; THIS SOFTWARE IS PROVIDED BY Robert Hayes ''AS IS'' AND ANY
; EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
; WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
; DISCLAIMED. IN NO EVENT SHALL Robert Hayes BE LIABLE FOR ANY
; DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
; (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
; ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
; (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
;
; You should have received a copy of the GNU General Public License
; along with this program. If not, see <http://www.gnu.org/licenses/>.
 
 
CPU XGATE
 
ORG $fe00
DS.W 2 ; reserve two words at channel 0, always unused for thread
; channel 1
DC.W SK_ENCRYPT ; point to start address
DC.W ROUND_E ; point to initial variables (Loaded into R1)
; channel 2
DC.W SK_DECRYPT ; point to start address
DC.W ROUND_D ; point to initial variables (Loaded into R1)
; channel 3
DC.W _ERROR ; point to start address
DC.W V_PTR ; point to initial variables
 
 
ORG $2000 ; Setup a data storage area
 
V_PTR EQU 123
 
 
;-------------------------------------------------------------------------------
; Constants used for offset caculations from R1 of SKIPJACK RAM variables.
; These offsets are used by both encrypt and decrypt routines.
;-------------------------------------------------------------------------------
SK_ROUND EQU 0
SK_W1 EQU 2
SK_W2 EQU 4
SK_W3 EQU 6
SK_W4 EQU 8
SK_KEY1 EQU 10
SK_KEY2 EQU 12
SK_KEY3 EQU 14
SK_KEY4 EQU 16
SK_KEY5 EQU 18
SK_KEY_P EQU 20
SK_F_P EQU 22
 
;-------------------------------------------------------------------------------
; RAM Variables for Skipjack Encryption
;-------------------------------------------------------------------------------
ROUND_E DC.W $55aa ; R1+0
PT DC.B $33,$22,$11,$00,$dd,$cc,$bb,$aa ; R1+2
KEYE_N DS.W 5 ; R1+10
KEYE_PTR DS.W 1 ; R1+20
F_PTR_E DC.W F_TABLE ; R1+22
 
KEY DC.B $99,$00,$77,$88,$55,$66,$33,$44,$11,$22
; R1 can only be used to explictly address the first 32 bytes
 
 
;-------------------------------------------------------------------------------
; Variables for Skipjack Decryption
;-------------------------------------------------------------------------------
ALIGN 1
ROUND_D DC.W $55aa ; R1+0
CT DC.B $25,$87,$ca,$e2,$7a,$12,$d3,$00 ; R1+2
KEYD_N DS.W 5 ; R1+10
KEYD_PTR DS.W 1 ; R1+20
F_PTR_D DC.W F_TABLE ; R1+22
 
KEYD DC.B $99,$00,$77,$88,$55,$66,$33,$44,$11,$22
; R1 can only be used to explictly address the first 32 bytes
 
ALIGN 1
 
;-------------------------------------------------------------------------------
; Place where undefined interrupts go
;-------------------------------------------------------------------------------
_ERROR
LDL R2,#$04 ; Sent Message to Testbench Error Register
LDH R2,#$80
LDL R3,#$ff
STB R3,(R2,#0)
 
SIF
RTS
 
 
;-------------------------------------------------------------------------------
; Skipjack Encryption
;-------------------------------------------------------------------------------
SK_ENCRYPT
;--- Only used for testbench, Delete for production release --------------------
LDL R2,#$00 ; Sent Message to Testbench Check Point Register
LDH R2,#$80
LDL R3,#$01
STB R3,(R2,#0)
STB R3,(R2,#2) ; Send Message to clear Testbench interrupt register
;-------------------------------------------------------------------------------
 
; Copy and invert key so we can use the native XNOR functions
; Because this is only required to be done once the Host may implement
; the key inversion and then this code could be deleted.
LDL R3,#KEY
LDH R3,#KEY>>8 ; R3 is address of KEY
 
LDW R6,(R3,#0)
COM R6
STW R6,(R1,#SK_KEY1)
LDW R6,(R3,#2)
COM R6
STW R6,(R1,#SK_KEY2)
LDW R6,(R3,#4)
COM R6
STW R6,(R1,#SK_KEY3)
LDW R6,(R3,#6)
COM R6
STW R6,(R1,#SK_KEY4)
LDW R6,(R3,#8)
COM R6
STW R6,(R1,#SK_KEY5)
 
; The following code to initialize the F Table pointer could be done by the host
; to save a few cycles of execution since it is only needed to be done once.
LDL R5,#F_TABLE
LDH R5,#F_TABLE>>8 ; R5 is address of F Table Pointer
STW R5,(R1,#SK_F_P) ; Save F Table Pointer
 
; Start of the SKIPJACK encrypt code
AND R3,R3,R0 ; Clear R3
STW R3,(R1,#SK_ROUND) ; Save initial Round Counter
LDL R3,#SK_KEY1 ; Set the initial Key counter value
STW R3,(R1,#SK_KEY_P) ; Save Key counter initial value
 
SKE_LOOP:
LDW R3,(R1,#SK_KEY_P) ; Get Key Counter value
LDW R7,(R1,R3+) ; Get word of Key
CMPL R3,#(SK_KEY5+2) ; Check for rollover
BNE SKE_K1_OK ; Branch if rollover
LDL R3,#SK_KEY1 ; Set the initial Key counter value
 
SKE_K1_OK:
STW R3,(R1,#SK_KEY_P) ; Save Key Pointer
LDW R5,(R1,#SK_F_P) ; Get F Table Base Address
LDL R4,#$70 ; Set Bitfield extract field
LDW R6,(R1,#SK_W1) ; Get W1
TFR R2,PC ; Subroutine Call
BRA CALC_G
 
LDW R3,(R1,#SK_KEY_P) ; Get Key Counter
LDW R7,(R1,R3+) ; Get word of Key
CMPL R3,#(SK_KEY5+2) ; Check for rollover
BNE SKE_K2_OK ; Branch if not rollover
LDL R3,#SK_KEY1 ; Set the initial Key counter value
 
SKE_K2_OK:
STW R3,(R1,#SK_KEY_P) ; Save Key Pointer
TFR R2,PC ; Subroutine Call
BRA CALC_G
 
LDW R3,(R1,#SK_ROUND) ; Load Round Counter
BITL R3,#8 ;
BNE SKE_RUL_B ; Do rule B when bit 3 of round counter is set
 
SKE_RUL_A:
ADDL R3,#1 ; Update the Round Counter
LDW R5,(R1,#SK_W4) ; Get W4
XNOR R5,R6,R5
XNOR R5,R5,R3 ; XOR the Round counter
LDW R7,(R1,#SK_W2) ; Load W2=NEXT_W3
BRA SKE_SHIFT ; R5=NEXT_W1, R6=NEXT_W2, R7=NEXT_W3
 
SKE_RUL_B:
ADDL R3,#1 ; Update Round Counter
LDW R7,(R1,#SK_W1) ; Get W1
XNOR R7,R7,R3 ; XNOR W1 and Round Counter
LDW R5,(R1,#SK_W2) ; Load W2
XNOR R7,R5,R7 ; XNOR previous result with W2
LDW R5,(R1,#SK_W4) ; Load W4=NEXT_W1
 
SKE_SHIFT:
STW R3,(R1,#SK_ROUND) ; Save the Round Counter
STW R5,(R1,#SK_W1) ; Store New W1
STW R6,(R1,#SK_W2) ; Store New W2
LDW R6,(R1,#SK_W3) ; Load W3
STW R6,(R1,#SK_W4) ; Store New W4
STW R7,(R1,#SK_W3) ; Store New W3
 
CMPL R3,#31 ; Check for last round
BRKP_3 BLS SKE_LOOP
 
 
;--- Only used for testbench, Delete for production release --------------------
LDL R2,#$00 ; Sent Message to Testbench Check Point Register
LDH R2,#$80
LDL R3,#$02
STB R3,(R2,#0)
;-------------------------------------------------------------------------------
 
SIF
RTS
 
 
CALC_G
BFEXT R3,R6,R4 ; Copy low byte of W1 to R3
BFINSX R3,R7,R4 ; XNOR the low byte of W1 with the low byte of KEY_N
ADD R3,R3,R5 ; Caculate full F Table byte address
LDB R3,(R3,#0) ; Get F Table output
ROL R6,#8 ; Move the high byte of W1 to the low byte of R6
BFINSX R6,R3,R4 ; XNOR the high byte of W1 with the F table output
BFINS R3,R6,R4 ; Copy low byte
ROL R6,#8 ; Put low byte of W1 back to the low byte of R6
 
ROL R7,#8 ; Move the high byte of KEY_N to the low byte of R7
BFINSX R3,R7,R4 ; XNOR temp with the high byte of KEY_N
 
ANDH R3,#0 ; Clear R3 high byte
ADD R3,R3,R5 ; Caculate full F Table byte address
LDB R3,(R3,#0) ; Get F Table output
BFINSX R6,R3,R4 ; XNOR the low byte of W1 with the F table output
 
JAL R2 ; Jump to return address
 
 
;-------------------------------------------------------------------------------
; Skipjack Decryption
;-------------------------------------------------------------------------------
SK_DECRYPT
;--- Only used for testbench, Delete for production release --------------------
LDL R2,#$00 ; Sent Message to Testbench Check Point Register
LDH R2,#$80
LDL R3,#$02
STB R3,(R2,#0)
STB R3,(R2,#2) ; Send Message to clear Testbench interrupt register
;-------------------------------------------------------------------------------
 
; Copy and invert key so we can use the native XNOR functions
; Because this is only required to be done once the Host may implement
; the key inversion and then this code could be deleted.
LDL R3,#KEYD
LDH R3,#KEYD>>8 ; R3 is address of KEY
 
LDW R6,(R3,#0)
COM R6
STW R6,(R1,#SK_KEY1)
LDW R6,(R3,#2)
COM R6
STW R6,(R1,#SK_KEY2)
LDW R6,(R3,#4)
COM R6
STW R6,(R1,#SK_KEY3)
LDW R6,(R3,#6)
COM R6
STW R6,(R1,#SK_KEY4)
LDW R6,(R3,#8)
COM R6
STW R6,(R1,#SK_KEY5)
 
; The following code to initialize the F Table pointer could be done by the host
; to save a few cycles of execution since it is only needed to be done once.
LDL R5,#F_TABLE
LDH R5,#F_TABLE>>8 ; R5 is address of F Table Pointer
STW R5,(R1,#SK_F_P) ; Save F Table Pointer
 
; Start of the SKIPJACK decrypt code
LDL R3,#32 ;
STW R3,(R1,#SK_ROUND) ; Save initial Round Counter
LDL R3,#SK_KEY5 ; Set the initial Key counter value
STW R3,(R1,#SK_KEY_P) ; Save Key counter initial value
 
SKD_LOOP:
LDW R3,(R1,#SK_KEY_P) ; Get Key Counter value
LDW R7,(R1,-R3) ; Get word of Key
CMPL R3,#(SK_KEY1) ; Check for rollover
BNE SKD_K1_OK ; Branch if rollover
LDL R3,#(SK_KEY5+2) ; Set the initial Key counter value
 
SKD_K1_OK:
STW R3,(R1,#SK_KEY_P) ; Save Key Pointer
LDW R5,(R1,#SK_F_P) ; Get F Table Base Address
LDL R4,#$70 ; Set Bitfield extract field
LDW R6,(R1,#SK_W2) ; Get W2
TFR R2,PC ; Subroutine Call
BRA CALC_GN
 
LDW R3,(R1,#SK_KEY_P) ; Get Key Counter
LDW R7,(R1,-R3) ; Get word of Key
CMPL R3,#(SK_KEY1) ; Check for rollover
BNE SKD_K2_OK ; Branch if not rollover
LDL R3,#(SK_KEY5+2) ; Set the initial Key counter value
 
SKD_K2_OK:
STW R3,(R1,#SK_KEY_P) ; Save Key Pointer
TFR R2,PC ; Subroutine Call
BRA CALC_GN ; Return with the new W1 in R6
 
LDW R3,(R1,#SK_ROUND) ; Load Round Counter
MOV R4,R3 ; Copy R3 to R4
SUBL R4,#1 ; New Round Counter used to pick Rule A or B
BITL R4,#8 ;
BNE SKD_RUL_B ; Do rule B when bit 3 of round counter is set
 
SKD_RUL_A:
LDW R5,(R1,#SK_W2) ; Get W2
LDW R2,(R1,#SK_W1) ; Get W1
XNOR R5,R2,R5
XNOR R5,R5,R3 ; XOR the Round counter
LDW R7,(R1,#SK_W3) ; Load R7=NEXT_W2
BRA SKD_SHIFT ; R6=NEXT_W1, R7=NEXT_W2, R5=NEXT_W4
 
SKD_RUL_B:
LDW R5,(R1,#SK_W3) ; Get W3
XNOR R7,R6,R3 ; XNOR G and Round Counter
XNOR R7,R7,R5 ; XNOR W3 R7=NEXT_W2
LDW R5,(R1,#SK_W1) ; Load R5=NEXT_W4
 
SKD_SHIFT:
STW R4,(R1,#SK_ROUND) ; Save the Round Counter
STW R6,(R1,#SK_W1) ; Store New W1
LDW R6,(R1,#SK_W4) ; Load W4
STW R6,(R1,#SK_W3) ; Store New W3
STW R7,(R1,#SK_W2) ; Store New W2
STW R5,(R1,#SK_W4) ; Store New W4
 
CMPL R4,#1
BRKP_1 BHS SKD_LOOP
 
 
;--- Only used for testbench, Delete for production release --------------------
LDL R2,#$00 ; Sent Message to Testbench Check Point Register
LDH R2,#$80
LDL R3,#$02
STB R3,(R2,#0)
;-------------------------------------------------------------------------------
SIF
RTS
 
 
CALC_GN
BRKP_2 ROL R7,#8 ; Flip bytes of KEY_N
ROL R6,#8 ; Flip bytes of W2
BFEXT R3,R6,R4 ; Copy high byte of W2 to R3
BFINSX R3,R7,R4 ; XNOR the high byte of W2 with the high byte of KEY_N
ADD R3,R3,R5 ; Caculate full F Table byte address
LDB R3,(R3,#0) ; Get F Table output
ROL R6,#8 ; Swap the bytes of W2 back to starting place
BFINSX R6,R3,R4 ; XNOR the low byte of W2 with the F table output
 
ROL R7,#8 ; Flip bytes of KEY_N back to starting place
BFEXT R3,R6,R4 ; Copy low byte of W2 to R3
BFINSX R3,R7,R4 ; XNOR W2 final with the low byte of KEY_N
 
ADD R3,R3,R5 ; Caculate full F Table byte address
LDB R3,(R3,#0) ; Get F Table output
ROL R6,#8 ; Put high byte of W2 to the low byte of R6
BFINSX R6,R3,R4 ; XNOR the high byte of W2 with the F table output
ROL R6,#8 ; Put high byte of W2 back to the high byte of R6
 
JAL R2 ; Jump to return address
 
;-------------------------------------------------------------------------------
;-------------------------------------------------------------------------------
;-------------------------------------------------------------------------------
 
; Note locations in the $8000 range are used by the testbench
 
ORG $8040
 
; These memory locations are read by the testbench debugger to trigger
; register captures when the saved address if used
BREAK_CAPT_0 DC.W SKD_K1_OK
BREAK_CAPT_1 DC.W BRKP_1
BREAK_CAPT_2 DC.W BRKP_2
BREAK_CAPT_3 DC.W $0000
BREAK_CAPT_4 DC.W SKE_LOOP
BREAK_CAPT_5 DC.W BRKP_3
BREAK_CAPT_6 DC.W SKD_LOOP
BREAK_CAPT_7 DC.W BRKP_1
 
ORG $9000
 
; This is the inverted F Table that is used by the G Function
F_TABLE:
DC.B $5C,$28,$F6,$7C,$07,$B7,$09,$0B
DC.B $4C,$DE,$EA,$87,$66,$4E,$50,$06
DC.B $18,$D2,$B2,$75,$31,$B3,$35,$D1
DC.B $AD,$6A,$26,$E1,$B1,$C7,$BB,$D7
DC.B $F5,$20,$FD,$5F,$E8,$0E,$9F,$97
DC.B $ED,$48,$85,$3C,$16,$05,$C2,$AC
DC.B $69,$7B,$94,$45,$0D,$9C,$65,$E6
DC.B $83,$51,$1A,$0A,$08,$E9,$95,$5D
DC.B $C6,$49,$84,$F0,$3E,$6C,$7E,$E4
DC.B $11,$4B,$E5,$15,$2F,$6E,$D0,$47
DC.B $AA,$46,$25,$7A,$C0,$BE,$40,$1F
DC.B $A5,$A7,$7F,$A0,$99,$F4,$27,$6F
DC.B $CA,$2A,$3F,$58,$CC,$F9,$9A,$96
DC.B $BA,$FF,$6B,$A9,$92,$67,$64,$89
DC.B $68,$03,$4D,$3D,$4F,$01,$24,$DF
DC.B $1E,$14,$29,$1B,$22,$B8,$B5,$E2
DC.B $BD,$12,$61,$91,$B6,$C3,$32,$BC
DC.B $D8,$2D,$F8,$2B,$21,$38,$98,$E7
DC.B $76,$34,$CF,$E0,$72,$39,$70,$55
DC.B $37,$8B,$23,$36,$A2,$A3,$CE,$5B
DC.B $8F,$77,$9E,$D3,$60,$F2,$D4,$78
DC.B $AF,$7D,$AB,$9B,$D9,$82,$FC,$BF
DC.B $CB,$B4,$E3,$8C,$2E,$3B,$02,$C4
DC.B $33,$04,$80,$54,$19,$C1,$A4,$5A
DC.B $52,$FB,$DC,$63,$EB,$AE,$DD,$0F
DC.B $D6,$86,$8E,$81,$00,$73,$F1,$1D
DC.B $F3,$10,$43,$8D,$8A,$90,$C8,$5E
DC.B $13,$2C,$71,$9D,$74,$79,$EF,$17
DC.B $F7,$88,$EE,$41,$6D,$B0,$DB,$3A
DC.B $CD,$C9,$62,$30,$0C,$59,$44,$53
DC.B $A1,$93,$56,$EC,$A8,$DA,$4A,$1C
DC.B $42,$57,$C5,$FE,$FA,$A6,$D5,$B9
 
;-------------------------------------------------------------------------------
; This is the un-inverted F Table and it is included for reference only
; Not required
DC.B $a3,$d7,$09,$83,$f8,$48,$f6,$f4
DC.B $b3,$21,$15,$78,$99,$b1,$af,$f9
DC.B $e7,$2d,$4d,$8a,$ce,$4c,$ca,$2e
DC.B $52,$95,$d9,$1e,$4e,$38,$44,$28
DC.B $0a,$df,$02,$a0,$17,$f1,$60,$68
DC.B $12,$b7,$7a,$c3,$e9,$fa,$3d,$53
DC.B $96,$84,$6b,$ba,$f2,$63,$9a,$19
DC.B $7c,$ae,$e5,$f5,$f7,$16,$6a,$a2
DC.B $39,$b6,$7b,$0f,$c1,$93,$81,$1b
DC.B $ee,$b4,$1a,$ea,$d0,$91,$2f,$b8
DC.B $55,$b9,$da,$85,$3f,$41,$bf,$e0
DC.B $5a,$58,$80,$5f,$66,$0b,$d8,$90
DC.B $35,$d5,$c0,$a7,$33,$06,$65,$69
DC.B $45,$00,$94,$56,$6d,$98,$9b,$76
DC.B $97,$fc,$b2,$c2,$b0,$fe,$db,$20
DC.B $e1,$eb,$d6,$e4,$dd,$47,$4a,$1d
DC.B $42,$ed,$9e,$6e,$49,$3c,$cd,$43
DC.B $27,$d2,$07,$d4,$de,$c7,$67,$18
DC.B $89,$cb,$30,$1f,$8d,$c6,$8f,$aa
DC.B $c8,$74,$dc,$c9,$5d,$5c,$31,$a4
DC.B $70,$88,$61,$2c,$9f,$0d,$2b,$87
DC.B $50,$82,$54,$64,$26,$7d,$03,$40
DC.B $34,$4b,$1c,$73,$d1,$c4,$fd,$3b
DC.B $cc,$fb,$7f,$ab,$e6,$3e,$5b,$a5
DC.B $ad,$04,$23,$9c,$14,$51,$22,$f0
DC.B $29,$79,$71,$7e,$ff,$8c,$0e,$e2
DC.B $0c,$ef,$bc,$72,$75,$6f,$37,$a1
DC.B $ec,$d3,$8e,$62,$8b,$86,$10,$e8
DC.B $08,$77,$11,$be,$92,$4f,$24,$c5
DC.B $32,$36,$9d,$cf,$f3,$a6,$bb,$ac
DC.B $5e,$6c,$a9,$13,$57,$25,$b5,$e3
DC.B $bd,$a8,$3a,$01,$05,$59,$2a,$46
;-------------------------------------------------------------------------------
 
 
_BENCH DS.W 8
 
 
/trunk/sw/applications/skipjack-1.01/README.txt
0,0 → 1,37
// 45678901234567890123456789012345678901234567890123456789012345678901234567890
Bob Hayes -- August 10, 2010
 
SKIPJACK ENCRYPT/DECRYPT for xgate RISC processor core
Version 0.1 Basic SKIPJACK Encrypt and Decrypt modules for the Xgate
processor. These routines do the basic codebook encrypt and decrypt
functions, other modes of use such as output feedback,cipher feedback and
cipher block chaining can be added at the host code level or the routines
could be expanded to incorporate the required functionality.
 
This implementation is believed to be compliant with the SKIPJACK algorithm
as described in "SKIPJACK and KEA Algorithm Specifications" Version 2.0
dated 29 May 1998, which is available from the National Institute for
Standards and Technology:
http://csrc.nist.gov/groups/STM/cavp/documents/skipjack/skipjack.pdf
The algorithm encrypts a 64 bit block of data with an 80 bit key running
through the encryption loop 32 times. The encrypt/decrypt function has been
verified by running the key and plain text and cypher test given in the
specification document.(Some have noted that this only verifies about half
of the entries in the F Table.)
Basic encryption process takes approx. 6468 cycles
Basic decryption process takes approx. 6786 cycles
The code has several sections that are only needed for the Verilog test bench
and can be deleted in normal use. There is also some additional initialization
code that only needs to be done once and could be replaced by the host putting
the correct values in the appropriate RAM locations. These sections are marked
in the code. The starting address of the F Table in memory shouldn't be critical
although starting on a 256 byte boundary is convenient for debugging. The
algorithm variables use 8 bit address offset calculations so care should be
taken if the key is saved in a memory range that crosses an 8 bit addressing
boundary.
 
 
/trunk/sw/applications/skipjack-1.01/make_core.scr
0,0 → 1,3
../../tools/HSW12ASM/hsw12asm.pl skipjack.s
../../tools/s_2_verilog skipjack_pag.s28
mv skipjack_pag.v ../../../bench/verilog/skipjack.v
trunk/sw/applications/skipjack-1.01/make_core.scr Property changes : Added: svn:executable ## -0,0 +1 ## +* \ No newline at end of property

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.