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Re: Incorrect SHA1 checksum for files 4GB+ [message #50005 is a reply to message #50002]

Sat, 16 June 2018 11:19

Zbych
Messages: 327
Registered: July 2009

Senior Member

I've made some further tests:
1. reading and writing file using Upp's stream - no difference between original file and copy was detected.
2. replace Upp's sha1 with some random sha1 from git: https://github.com/clibs/sha1 - now checksum is the same as from sha1sum.
3. optimization level doesn't change result (both Upp's sha1 and git's)

Test app that calculates sha1 using Upp and git version at the same time is attached.

4GB file:

16.06.2018 11:11:27 File '/tmp/file4GB.bin' sha1 calculation started
16.06.2018 11:12:03 UPP SHA1: 1e4aca8da9f53733575cd351347b6a054a098bf5
16.06.2018 11:12:03 GIT SHA1: d43db14ac2c197da7d4d0048105f2af0bcb75f0b

$ sha1sum /tmp/file4GB.bin 
d43db14ac2c197da7d4d0048105f2af0bcb75f0b  /tmp/file4GB.bin

File smaller than 4GB:

16.06.2018 11:17:39 File '/tmp/file4GB-.bin' sha1 calculation started
16.06.2018 11:18:16 UPP SHA1: 30c411fa4ca4ed06b54ecb6143abcd39f2c32591
16.06.2018 11:18:16 GIT SHA1: 30c411fa4ca4ed06b54ecb6143abcd39f2c32591

$ sha1sum /tmp/file4GB-.bin 
30c411fa4ca4ed06b54ecb6143abcd39f2c32591  /tmp/file4GB-.bin

Attachment: sha1test.zip
(Size: 4.43KB, Downloaded 212 times)

[Updated on: Sat, 16 June 2018 11:27]

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