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checksums: Ugly fix for incremental checksums. Add randomized unit tests to ensure that varying length payloads are the same incrementally or all at once.

char-rename
Doug Coleman 2016-07-09 16:59:15 -05:00
parent d6d4e0e903
commit 217b7f2b0c
2 changed files with 62 additions and 15 deletions
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41
basis/checksums/common/common.factor
View File

@ -2,7 +2,7 @@
! See http://factorcode.org/license.txt for BSD license.
USING: accessors byte-arrays byte-vectors checksums grouping io
io.backend io.binary io.encodings.binary io.files kernel make
math sequences ;
math sequences locals ;
IN: checksums.common
: calculate-pad-length ( length -- length' )
@ -38,19 +38,32 @@ GENERIC: checksum-block ( bytes checksum-state -- )
GENERIC: get-checksum ( checksum-state -- value )
: add-checksum-bytes ( checksum-state data -- checksum-state' )
[
over bytes>> [ push-all ] keep
[ dup length pick block-size>> >= ]
[
over block-size>> cut-slice [
over checksum-block
[ block-size>> ] keep [ + ] change-bytes-read
] dip
] while
>byte-vector >>bytes
] keep
length 64 mod [ + ] curry change-bytes-read ;
: next-level ( n size -- n' )
2dup mod [ + ] [ - + ] if-zero ; inline
! Update the bytes-read before calculating checksum in case checksum uses
! this in the calculation.
:: add-checksum-bytes ( state data -- state' )
state block-size>> :> block-size
state bytes>> length :> initial-len
data length :> data-len
initial-len data-len + :> total-len
total-len block-size /mod :> ( n extra )
data state bytes>> [ push-all ] keep :> all-bytes
n zero? [
state [ data-len + ] change-bytes-read drop
] [
all-bytes block-size <groups> [ length 64 = ] partition [
[ state [ block-size next-level ] change-bytes-read drop state checksum-block ] each
BV{ } clone state bytes<<
] [
[
first
[ length state [ + ] change-bytes-read drop ]
[ >byte-vector state bytes<< ] bi
] unless-empty
] bi*
] if state ;
: add-checksum-stream ( checksum-state stream -- checksum-state )
[ [ add-checksum-bytes ] each-block ] with-input-stream ;

36
basis/checksums/sha/sha-tests.factor
View File

@ -1,6 +1,6 @@
USING: arrays checksums checksums.common checksums.sha
checksums.sha.private io.encodings.binary io.streams.byte-array
kernel math.parser sequences tools.test ;
kernel math.parser sequences tools.test random ;
IN: checksums.sha.tests
: test-checksum ( text identifier -- checksum )
@ -75,3 +75,37 @@ CONSTANT: bytes-b B{ 1 2 3 4 5 6 7 8 }
sha1 initialize-checksum-state bytes-a bytes-b append add-checksum-bytes get-checksum
sha1 initialize-checksum-state bytes-a add-checksum-bytes bytes-b add-checksum-bytes get-checksum =
] unit-test
: incremental-checksum ( algorithm seqs -- checksum )
[ initialize-checksum-state ] dip
[ add-checksum-bytes ] each get-checksum ;
: one-go-checksum ( algorithm seqs -- checksum )
[ initialize-checksum-state ] dip
concat add-checksum-bytes get-checksum ;
ERROR: checksums-differ algorithm seq incremental-checksum one-go-checksum ;
: compare-checksum-calculations ( algorithm seq -- ? )
2dup [ incremental-checksum ] [ one-go-checksum ] 2bi 2dup = [
2drop 2drop t
] [
checksums-differ
] if ;
{ t } [ 100 iota [ drop sha1 100 [ 100 random random-bytes ] replicate compare-checksum-calculations ] all? ] unit-test
{ t } [ 100 iota [ drop sha1 20 [ 20 random random-bytes ] replicate compare-checksum-calculations ] all? ] unit-test
{ t } [ 100 iota [ drop sha1 10 [ 10 random random-bytes ] replicate compare-checksum-calculations ] all? ] unit-test
{ t } [ sha1 {
B{ 105 27 166 214 73 114 110 }
B{ 39 162 16 218 0 42 }
B{ 129 235 197 233 }
B{ 61 29 254 66 67 }
B{ 28 236 253 45 240 123 134 191 22 }
B{ 220 27 205 59 27 48 }
B{ 249 2 196 177 74 195 12 131 91 }
B{ 174 102 159 89 250 38 230 5 }
B{ 126 22 231 253 118 64 }
B{ 185 127 20 126 123 35 204 243 43 }
} compare-checksum-calculations
] unit-test