What type of encoding/encryption has been used?

Question

Encrypted output:

mgmt_opq=kdS+yok8yWM=:zS0U62VvOPI=:6C9zqH5bnu4=

Read all related posts, tried with Base64 decoders but didn't work.

Additional info

The output should be an Ethernet MAC address: 6 bytes, 48bits.

# fw_printenv | grep opq
mgmt_opq=kdS+yok8yWM=:zS0U62VvOPI=:6C9zqH5bnu4=

kdS+yok8yWM= should be the first word(16 bit) of MAC address

zS0U62VvOPI= should be second word of MAC address

6C9zqH5bnu4= should be third word of MAC address

Where did you get this string from? Knowing that would probably help. — John Wu, Jan 16 '17 at 00:41
is the output of a MAC address 48 bits, 6 bytes. 16bits:16bits:16bits i guess — Adrian Constantin Oprea, Jan 16 '17 at 00:48
fw_printenv | grep opq
mgmt_opq=kdS+yok8yWM=:zS0U62VvOPI=:6C9zqH5bnu4= — Adrian Constantin Oprea, Jan 16 '17 at 00:55
cat /proc/cpuinfo
Processor : ARM926EJ-S rev 1 (v5l) BogoMIPS : 1192.75 Features : swp half thumb fastmult edsp CPU implementer : 0x56 CPU architecture: 5TE CPU variant : 0x2 CPU part : 0x131 CPU revision : 1 Cache type : write-back Cache clean : cp15 c7 ops Cache lockdown : format C Cache format : Harvard I size : 16384 I assoc : 4 I line length : 32 I sets : 128 D size : 16384 D assoc : 4 D line length : 32 D sets : 128 — Adrian Constantin Oprea, Jan 16 '17 at 00:56
cat /proc/version
Linux version 2.6.22.18 (gcc version 4.2.0 20070413 (prerelease)) #1 Sun Aug 7 07:41:37 IDT 2016 — Adrian Constantin Oprea, Jan 16 '17 at 00:56
@AdrianConstantinOprea Is the answer below not enough or why are you still extending the question? (Oh, now it's gone...) — deviantfan, Jan 16 '17 at 01:05

Arminius · Answer 1 · 2017-01-16T01:13:46.823

2

Your output contains three colon-separated strings which are valid base64 sequences.

You shouldn't assume that base64-decoded data is always in the printable ASCII range since you can encode arbitrary binary. Here is the output:

kdS+yok8yWM=
00000000: 91d4 beca 893c c963                      .....<.c

zS0U62VvOPI=
00000000: cd2d 14eb 656f 38f2                      .-..eo8.

6C9zqH5bnu4=
00000000: e82f 73a8 7e5b 9eee                      ./s.~[..

That doesn't match the format of a single MAC address (48 bit) because each of the three segments has a length of 8 bytes (64 bit).

edited Jan 16 '17 at 01:13

answered Jan 16 '17 at 00:42

Arminius

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kdS+yok8yWM= 00000000: 91d4 beca 893c c963 .....<.c
zS0U62VvOPI= 00000000: cd2d 14eb 656f 38f2 .-..eo8.

6C9zqH5bnu4= 00000000: e82f 73a8 7e5b 9eee ./s.~[.. But this doesnt make sense, right ? tried with Base64 saw the same thing, but the output should be a MAC address. 16bit:16bit:16bit
– Adrian Constantin Oprea Jan 16 '17 at 00:47
why "-2" votes ? dumb question or what? – Adrian Constantin Oprea Jan 16 '17 at 00:51
1

@AdrianConstantinOprea You question was downvoted because you didn't provide any context and "what is that encryption?" questions are generally discouraged. – Arminius Jan 16 '17 at 00:53
I see. Sorry for that. I do research a lot before i ask. – Adrian Constantin Oprea Jan 16 '17 at 00:57
Any other thoughts other than Base64 ? – Adrian Constantin Oprea Jan 16 '17 at 01:12
@AdrianConstantinOprea I still think it's base64. That's consistent with the character range and the padding (=) at the end. – Arminius Jan 16 '17 at 01:17
Strange output. Should be a MAC address but like you said every segment has 8 bytes. hmm... – Adrian Constantin Oprea Jan 16 '17 at 01:18
now its "-3" :) – Adrian Constantin Oprea Jan 16 '17 at 01:29
@AdrianConstantinOprea If you have found a solution you can post it as an answer. :) – Arminius Jan 16 '17 at 02:03
I asked the device's vendor to provide an explanation. – Adrian Constantin Oprea Jan 16 '17 at 02:07

score 0 · Answer 2 · edited Jan 16 '17 at 07:39

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It was that mgmt_opq=kdS+yok8yWM=:zS0U62VvOPI=:6C9zqH5bnu4= it is a key (opaque format) used by the vendor to register the specified device to a server database.

Opaque data type:

https://en.wikipedia.org/wiki/Opaque_data_type

edited Jan 16 '17 at 07:39

schroeder

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answered Jan 16 '17 at 02:59

Adrian Constantin Oprea

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So it was no MAC address after all, like you said before Sigh. And I don't get what part about a key/serial is an unknown format. Raw encryption keys or pseudorandom serial data are not supposed to have some human-readable format. – deviantfan Jan 16 '17 at 14:34
@deviantfan Youre right. They call this key "Opaque MAC". – Adrian Constantin Oprea Jan 17 '17 at 00:43

What type of encoding/encryption has been used?

Additional info

2 Answers2