🍖Protected File Transfers

File Encryption on Windows

One of the simplest methods is the Invoke-AESEncryption.ps1 PowerShell script for enryption of files and strings.

.EXAMPLE
Invoke-AESEncryption -Mode Encrypt -Key "p@ssw0rd" -Text "Secret Text" 

Description
-----------
Encrypts the string "Secret Test" and outputs a Base64 encoded ciphertext.
 
.EXAMPLE
Invoke-AESEncryption -Mode Decrypt -Key "p@ssw0rd" -Text "LtxcRelxrDLrDB9rBD6JrfX/czKjZ2CUJkrg++kAMfs="
 
Description
-----------
Decrypts the Base64 encoded string "LtxcRelxrDLrDB9rBD6JrfX/czKjZ2CUJkrg++kAMfs=" and outputs plain text.

Or for a file ->

#Encrypt
Invoke-AESEncryption -Mode Encrypt -Key "p@ssw0rd" -Path file.bin

#Decrypt
Invoke-AESEncryption -Mode Decrypt -Key "p@ssw0rd" -Path file.bin.aes

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After the script has been transferred, it only needs to be imported as a module ->

PS C:\htb> Import-Module .\Invoke-AESEncryption.ps1

File Encryption on Linux

To encrypt a file using openssl we can select different ciphers like -aes256. We can also override the default iterations counts with the option -iter 100000 and add the option -pbkdf2 to use the Password-Based Key Derivation Function 2 algorithm

Let's try encrypting /etc/passwd ->

ElFelixi0@htb[/htb]$ openssl enc -aes256 -iter 100000 -pbkdf2 -in /etc/passwd -out passwd.enc

and to decrypt it ->

ElFelixi0@htb[/htb]$ openssl enc -d -aes256 -iter 100000 -pbkdf2 -in passwd.enc -out passwd