#6 HMAC problem

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nobody
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5
2008-11-13
2008-11-13
Thierry Micholt
No

My observations when HMAC(SHA1) is selected for multiple files:

Only the HMAC(SHA1) Message Digest of the FIRST file is correct!

Subsequent files show an incorrect Message Digest when compared to a known Message Digest source (e.g. HashCalc).

See the following test results for 3 identical files:

Test 1 no HMAC
File;crc32;sha1
C:\rng1.bin;C8BC3697;081B784484390550305DF369E20877756A68E06E
C:\rng6.bin;C8BC3697;081B784484390550305DF369E20877756A68E06E
C:\rng7.bin;C8BC3697;081B784484390550305DF369E20877756A68E06E

Test 2 HMAC
File;sha1
C:\rng1.bin;90D4BD1410916BF857B977F3A6449DC558263294
C:\rng6.bin;0D657F4DD9D05AD82DBD212B8314A0C6C752B69C
C:\rng7.bin;0D657F4DD9D05AD82DBD212B8314A0C6C752B69C

HashCalc:
C:\rng1.bin - 90d4bd1410916bf857b977f3a6449dc558263294
C:\rng6.bin - 90d4bd1410916bf857b977f3a6449dc558263294
C:\rng7.bin - 90d4bd1410916bf857b977f3a6449dc558263294

Also: HMAC seed is a Text String (not Hex.)

Steve N.

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