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encryption - Decrypt SSL traffic with the openssl command line tool 7

Generating the master secret/key I followed the steps outlined in my shell script. I validated that I am passing data correctly to it by manually entering these steps several times (entering $key manually) and ultimately I arrive at the same outcome/data in this case


key = decrypted pre master key from previous step


03033ab0d673caefc4a9f6d35cf51d349815d67a09ac454f11dfb9741c96001a
66a3e82f688b82138403018384cf35f2

mseed.key = "master secret" + client.random + server.random The file is a binary file when I use that the hexdump xxd -p mseed.key so you can see the data:


6d617374657220736563726574 5b689404b500456eef2f1a79ec782eb3ee
aac3a8d7c02ae03c8426f363b18a33 5b6894043bb1289e158b0278ef66dc
53c9fa71e75e900739af2657cd4476ec1e

Note: the spaces are not in the data I added those manually to make it clear

client.random xxd -p crnd.bin


5b689404b500456eef2f1a79ec782eb3eeaac3a8d7c02ae03c8426f363b1
8a33

server.random xxd - srnd.bin


5b6894043bb1289e158b0278ef66dc53c9fa71e75e900739af2657cd4476
ec1e

just so I am clear those randoms also include the unix time prefixed (correct?)


key=${1} #passed to shell script 
openssl dgst -sha256 -mac hmac -macopt hexkey:$key a1
openssl dgst -sha256 -mac hmac -macopt hexkey:$key a2
openssl dgst -sha256 -mac hmac -macopt hexkey:$key a3
openssl dgst -sha256 -mac hmac -macopt hexkey:$key a4

The next step is:


cat a1 mseed.key | openssl dgst -sha256 -mac hmac -macopt hexkey:$key -binary >k1
cat a2 mseed.key | openssl dgst -sha256 -mac hmac -macopt hexkey:$key -binary >k2
cat a3 mseed.key | openssl dgst -sha256 -mac hmac -macopt hexkey:$key -binary >k3   
cat a4 mseed.key | openssl dgst -sha256 -mac hmac -macopt hexkey:$key -binary >k4

Follwed by extracting the master secret


cat k1 k2 | head -c48 | xxd -p -c48 > master_secret.hex
truncate -s-1 master_secret.hex

master_secret at this point


$cat master_secret.hex
ee45b637f95ddf3b3bf51661cdf4e07bdd63a67f2d2df776322992b3fd871fe4ba38debcd7179bf4
ef8b8bb814fe4544d

From my wireshark log I extracted the client random during the conversation and saved it as the binary file crnd.bin


Random: 5b689404b500456eef2f1a79ec782eb3eeaac3a8d7c02ae0...
    GMT Unix Time: Aug  6, 2018 14:31:32.000000000 Eastern Daylight Time
    Random Bytes: b500456eef2f1a79ec782eb3eeaac3a8d7c02ae03c8426f3...

Subsequently I capture the server time and random bytes and save it as srnd.bin


Random: 5b6894043bb1289e158b0278ef66dc53c9fa71e75e900739...
    GMT Unix Time: Aug  6, 2018 14:31:32.000000000 Eastern Daylight Time
    Random Bytes: 3bb1289e158b0278ef66dc53c9fa71e75e900739af2657cd...

Dave, At this point I am stumped what I could be missing. I don't think I am missing something like a null in a variable or anything I've meticulously gone over the data and steps and don't see what I could be missing. Do you spot anything with these steps? Thanks

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