MD5 Hash modified trought netcat

Question

I used dd to create a sample empty file with 1MB, edited the sample file, created a MD5 hash of the file, started a listener on the examiner machine, piped the output off to nc and compared the hashes. Why does the hash value is modified if i transmited the same data from the same file to it?

dd if=/dev/zero of=/CaseStudies/sample.dd bs=1M count=1
hexedit sample.dd
ENTER
0x20000
68 65 72 65  20 49 20 61  6D 0A
Ctrl-X
dd if=/CaseStudies/sample.dd bs=4k | md5sum

output:

fc3ef9193baf3a1d3fc67da5aa4510ae

nc -lp 4444 > sample.dd
dd if=/CaseStudies/sample.dd bs=4k | nc -w3 127.0.0.1 4444
md5sum sample.dd

output:

d41d8cd98f00b204e9800998ecf8427e sample.dd

cmp sample.dd copy.dd

output:

cmp: EOF on sample.dd which is empty

For some reason the netcat isn't being able of sending the data through the connection. Could someone help me figuring out why?

Is your current working directory /CaseStudies/? See Bending a pipeline back into its origin. Does this answer your question? — Kamil Maciorowski, Jul 20 '23 at 05:03
For some reason the netcat isn't being able of sending the data through the connection. EOF on sample.dd which is empty This is your issue, not checksums changing. — Artem S. Tashkinov, Jul 20 '23 at 07:51

MD5 Hash modified trought netcat

0 Answers0