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author | Keith Isdale <keith.isdale@nokia.com> | 2010-07-26 14:56:53 +1000 |
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committer | Keith Isdale <keith.isdale@nokia.com> | 2010-07-26 14:56:53 +1000 |
commit | 9f034793bcfc51c2b7c1dd14db806f7258f9a9eb (patch) | |
tree | 63bd0f50ce5b77828ad8205eafd7b9412810499e /botan/src/checksum/adler32/adler32.cpp | |
parent | 619d92cfef29e653bfdf852e83888e50cfc4348f (diff) | |
parent | 65271649dbc90f3af1184ad1b23bdb64c0c07d07 (diff) |
Merge branch 'master' of git://git-nokia.trolltech.com.au/qtsoftware/research/qtuitest
Diffstat (limited to 'botan/src/checksum/adler32/adler32.cpp')
-rw-r--r-- | botan/src/checksum/adler32/adler32.cpp | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/botan/src/checksum/adler32/adler32.cpp b/botan/src/checksum/adler32/adler32.cpp new file mode 100644 index 0000000..c66943b --- /dev/null +++ b/botan/src/checksum/adler32/adler32.cpp @@ -0,0 +1,74 @@ +/* +* Adler32 +* (C) 1999-2007 Jack Lloyd +* +* Distributed under the terms of the Botan license +*/ + +#include <botan/adler32.h> +#include <botan/loadstor.h> + +namespace Botan { + +/* +* Adler32 Checksum +*/ +void Adler32::hash(const byte input[], u32bit length) + { + u32bit S1x = S1, S2x = S2; + while(length >= 16) + { + S1x += input[ 0]; S2x += S1x; + S1x += input[ 1]; S2x += S1x; + S1x += input[ 2]; S2x += S1x; + S1x += input[ 3]; S2x += S1x; + S1x += input[ 4]; S2x += S1x; + S1x += input[ 5]; S2x += S1x; + S1x += input[ 6]; S2x += S1x; + S1x += input[ 7]; S2x += S1x; + S1x += input[ 8]; S2x += S1x; + S1x += input[ 9]; S2x += S1x; + S1x += input[10]; S2x += S1x; + S1x += input[11]; S2x += S1x; + S1x += input[12]; S2x += S1x; + S1x += input[13]; S2x += S1x; + S1x += input[14]; S2x += S1x; + S1x += input[15]; S2x += S1x; + input += 16; + length -= 16; + } + for(u32bit j = 0; j != length; ++j) + { + S1x += input[j]; S2x += S1x; + } + S1x %= 65521; + S2x %= 65521; + S1 = S1x; + S2 = S2x; + } + +/* +* Update an Adler32 Checksum +*/ +void Adler32::add_data(const byte input[], u32bit length) + { + const u32bit PROCESS_AMOUNT = 5552; + while(length >= PROCESS_AMOUNT) + { + hash(input, PROCESS_AMOUNT); + input += PROCESS_AMOUNT; + length -= PROCESS_AMOUNT; + } + hash(input, length); + } + +/* +* Finalize an Adler32 Checksum +*/ +void Adler32::final_result(byte output[]) + { + store_be(output, S2, S1); + clear(); + } + +} |