How to decrypt the specified data?

Question

Cryptography

Hello! There is the following data in encrypted form (what is black):

Here is the black part in base64 format:

eJxFjctqwzAURP/lrq33tWJrGbLstt0WPa5jgyMVSaGFkH+vuyhZDRzmzDyAagUnh7+8tSu4fN/3AZLvHtwDPqi2rWRwIPnMDVdyPMEAq2/rwSwqklFZqy2aYAymlMIyjZFQj4j2aF7Kd96LT+91O4S19y8nREyZKcVp6az1UonHchNv/p7jSvWytV630MTr8XNWRuI8a4YYJoY6eea1JjYHY09xkTTpJM7t+r/BXy6nH4Ln8xd/QESc

The above data is known to be the result of AES-(128/192/256) encryption. Also, the following base64 string was extracted from the .exe, which can decrypt this data:

WT+fY3IKPLVJDEszF6MCAUnXPg9zSXR7JVQ0sT1rbhy/fG9dBhVoNbJcMzcLTRSOQE47R2V0VHlwZUZfb21IYW5kbGU7AWV0X05hbWU7SW5kZXhPZjtFeGl0O2dldF9GcmFtZUNvdW50O2dldF9MZW5ndGg7UmVhZFN0cmluZztBZGQ7Z2V0X1Bvc2l0aW9uO2dldF9DdXJyZW50RG9tYWluO1NldERhdGE7UnVudGltZU1ldGhvZDtTeXN0ZW0uRGlhZ25vc3RpY3MuU3RhY2tUcmFjZTtTeXN0ZW0uRGlhZ25vc3RpY3MuU3RhY2tGcmFtZTszNDI3MjtTeXN0ZW0uRW52aXJvbm1lbnQ7ZGU0ZG90O1NpbXBsZUFzc2VtYmx5RXhwbG9yZXI7YmFiZWx2bTtzbW9rZXRlc3Q=

After decoding it, the following data set was obtained:

Y?\x9fcr\n<\xb5I\x0cK3\x17\xa3\x02\x01I\xd7>\x0fsIt{%T4\xb1=kn\x1c\xbf|o]\x06\x15h5\xb2\\37\x0bM\x14\[email protected];GetTypeF_omHandle;\x01et_Name;IndexOf;Exit;get_FrameCount;get_Length;ReadString;Add;get_Position;get_CurrentDomain;SetData;RuntimeMethod;System.Diagnostics.StackTrace;System.Diagnostics.StackFrame;34272;System.Environment;de4dot;SimpleAssemblyExplorer;babelvm;smoketest

It is likely that the piece at the beginning is related to the key (not sure if this is part of the decoded string):

Y?\x9fcr\n<\xb5I\x0cK3\x17\xa3\x02\x01I\xd7>\x0fsIt{%T4\xb1=kn\x1c\xbf|o]\x06\x15h5\xb2\\37\x0bM\x14\[email protected]

Please help me find the key! Namely: to extract the key from all this, so that it can be used to successfully decrypt the data encrypted above. Thanks in advance!

Answer 1

And in general, you already have an http package.
Handshake goes on several levels, a little lower.
Read for example https://tls.dxdt.ru/tls.html