22 lines
539 B
Factor
22 lines
539 B
Factor
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USING: kernel math sequences namespaces ;
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IN: crypto-internals
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: crc32-polynomial HEX: edb88320 ; inline
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: crc32-init ( -- table )
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256 [
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8 [
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dup 1 bitand 0 >
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[ -1 shift crc32-polynomial bitxor ] [ -1 shift ] if
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] times
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] map ;
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SYMBOL: crc32-table crc32-init global [ crc32-table set ] bind
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: calc-crc32 ( crc ch -- crc )
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over bitxor HEX: ff bitand crc32-table get nth swap -8 shift bitxor ;
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IN: crypto
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: >crc32 ( seq -- n ) HEX: ffffffff [ swap [ calc-crc32 ] each ] keep bitxor ;
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