hash method to verify integrity of dir vs dir.tar.gz - bash

Question

I'm working on a python scrip that verify the integrity of some downloaded projects.
On my nas, I have all my compressed folder: folder1.tar.gz, folder2.tar.gz, …
On my Linux computer, the equivalent uncompressed folder : folder1, folder2, …
So, i want to compare the integrity of my files without any UnTar or download !
I think i can do it on the nas with something like (with md5sum):
sshpass -p 'pasword' ssh login#my.nas.ip tar -xvf /path/to/my/folder.tar.gz | md5sum | awk '{ print $1 }'
this give me a hash, but I don't know how to get an equivalent hash to compare with the normal folder on my computer. Maybe the way I am doing it is wrong.
I need one command for the nas, and one for the Linux computer, that output the same hash ( if the folders are the same, of course )

Answer 1

If you did that, tar xf would actually extract the files. md5sum would only see the file listing, and not the file content.
However, if you have GNU tar on the server and the standard utility paste, you could create checksums this way:
mksums:
#!/bin/bash
data=/path/to/data.tar.gz
sums=/path/to/data.md5
paste \
<(tar xzf "$data" --to-command=md5sum) \
<(tar tzf "$data" | grep -v '/$') \
| sed 's/-\t//' > "$sums"
Run mksums above on the machine with the tar file.
Copy the sums file it creates to the computer with the folders and run:
cd /top/level/matching/tar/contents
md5sums -c "$sums"
paste joins lines of files given as arguments
<( ...) runs a command, making its output appear in a fifo
--to-command is a GNU tar extension which allows running commands which will receive their data from stdin
grep filters out directories from the tar listing
sed removes the extraneous -\t so the checksum file can be understood by md5sum
The above assumes you don't have any very-oddly named files (for example, the names can't contain newlines)